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NASA has selected five science investigations for refinement during the next year as a first step in choosing one or two missions for flight opportunities as early as 2020. The submitted proposals would study Venus, near-Earth objects and a variety of asteroids.
Each investigation team will receive $3 million to conduct concept design studies and analyses. After a detailed review and evaluation of the concept studies, NASA will make the final selections by September 2016 for continued development leading up to launch. Any selected mission will cost approximately $500 million, not including launch vehicle funding or the cost of post-launch operations.
"The selected investigations have the potential to reveal much about the formation of our solar system and its dynamic processes," said John Grunsfeld, astronaut and associate administrator for NASA's Science Mission Directorate in Washington. "Dynamic and exciting missions like these hold promise to unravel the mysteries of our solar system and inspire future generations of explorers. It's an incredible time for science, and NASA is leading the way."
NASA's Discovery Program requested proposals for spaceflight investigations in November 2014. A panel of NASA and other scientists and engineers reviewed 27 submissions.
The planetary missions selected to pursue concept design studies are:
Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging (DAVINCI)
DAVINCI would study the chemical composition of Venus' atmosphere during a 63-minute descent. It would answer scientific questions that have been considered high priorities for many years, such as whether there are volcanoes active today on the surface of Venus and how the surface interacts with the atmosphere of the planet. Lori Glaze of NASA's Goddard Space Flight Center in Greenbelt, Maryland, is the principal investigator. Goddard would manage the project.
The Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy mission (VERITAS)
VERITAS would produce global, high-resolution topography and imaging of Venus' surface and produce the first maps of deformation and global surface composition. Suzanne Smrekar of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California is the principal investigator. JPL would manage the project.
Psyche would explore the origin of planetary cores by studying the metallic asteroid Psyche. This asteroid is likely the survivor of a violent hit-and-run with another object that stripped off the outer, rocky layers of a protoplanet. Linda Elkins-Tanton of Arizona State University in Tempe, Arizona is the principal investigator. JPL would manage the project.
Near Earth Object Camera (NEOCam)
NEOCAM would discover ten times more near-Earth objects than all NEOs discovered to date. It would also begin to characterize them. Amy Mainzer of JPL is the principal investigator, and JPL would manage the project.
Lucy would perform the first reconnaissance of the Jupiter Trojan asteroids, objects thought to hold vital clues to deciphering the history of the solar system. Harold Levison of the Southwest Research Institute in Boulder, Colorado is the principal investigator. Goddard would manage the project.
Created in 1992, the Discovery Program sponsors frequent, cost-capped solar system exploration missions with highly focused scientific goals. The program has funded and developed 12 missions to date, including MESSENGER, Dawn, Stardust, Deep Impact, Genesis and GRAIL, and is currently completing development of InSight. The Planetary Missions Program Office at NASA's Marshall Space Flight Center in Huntsville, Alabama manages the program for the agency's Science Mission Directorate.
For more information about NASA's Discovery Program, visit:

subset: commoncrawl


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Why your phone is damaging your brain
Do you have a phone addiction? If this is the case, you are not alone. It's challenging to go a day without utilizing some technological gadget in today's environment. According to an app that measures phone usage, we look at our phones an average of 58 times daily. This is causing brain damage. While there are several advantages to utilizing technology, there are also certain risks associated with excessive use. The damage that phone addiction may bring to our brains is one of the most frightening.
People, like any addiction, tend to use their phones more and more and then find it difficult to stop. Constantly carrying our phones might cause anxiety if we leave them at home or in the car by accident. Smartphone separation anxiety has been discovered as a serious source of stress that can trigger dread and fear of missing out. It stems from our increasing reliance on our phones for communication, information, directions, and reminders of what we are meant to accomplish that day. Nomophobia, or the dread of not always having our phone with us, has been given a name. Furthermore, concerns about a low battery, insufficient data or credit, and inadequate network coverage have prompted anxiety and even panic attacks.
We live in an age of immediate pleasure. As a result, another type of anxiety associated with smartphone use is the feeling you get when you send a message to someone and they don't respond right away or when there aren't enough "Likes" or comments on your newest social media post. On the other side, you have the impression that you should answer communications immediately but don't want to. This might generate anxiety as a result of guilt. All of this may seem trivial, but it produces worry in many individuals, which has harmful repercussions on the brain.
Over half of all eleven-year-old American youngsters own a smartphone. This is alarming since by age twelve, youngsters use their phones for slightly under five hours per day, rising to more than seven hours per day in teens. The first thing that comes to mind as a source of concern is that these children are playing games on their phones than outside. Physical activity promotes brain health, improves mood, attention, and concentration, and increases energy. When we use our cell phones, we tend to hop from one activity to the next, from one screen to the next, and from one program to the next. A study of this loss of attention when using cell phones discovered that it damages brain growth. Furthermore, excessive screen usage might cause the brain's outer layer to thin. This brain damage was discovered in the preliminary findings of research that followed the smartphone use of 11,000 youngsters for a decade. Observing how much damage these children's brains have sustained after 10 years will be intriguing.
In addition to worry, phone addiction can result in sleep deprivation, depression, transient memory loss, headaches, dizziness, and exhaustion. All of these things can harm the brain or impair its function.
Mobile phones prevent us from concentrating correctly. We insist on having them around so that even while we are working or attempting to focus on anything else, we are disturbed if we hear an alert. We wonder who has messaged us, what is going on on social media, and whether we have an email that has to be answered. According to one research, even when we are not using our smartphones, they demand our attention and make us uneasy.
Using a cell phone also promotes mental laziness. It's tempting to "Google" anything when you want to learn something new. This, however, does not allow you to exercise your grey matter. "Use it or lose it," as the old adage goes.
Smartphone use can potentially harm our brains by causing sadness. We only post good events and news on social media. We may also use technology to apply filters to our images to make us appear immaculate. This, however, might be interpreted as living a great life, looking stunning, and loving every second of it. When people view these messages on a regular basis, it can make them feel inadequate, diminish their self-esteem, feel lonely, and feel as if they are missing out, all of which can contribute to depression. Worryingly, smartphone internet use can drive people, particularly adolescents, to self-harm or even commit suicide. This is a very concerning component that has the potential to harm the brain by creating psychological and emotional anguish. Having said that, one research found that being sad actually pushes people to utilize social media to seek validation in the form of likes or comments.
The Dangers of Blue Light
We've all heard that excessive screen time is hazardous for our eyesight. But did you know that the blue light emitted by screens can also be harmful to our brain health? Blue light is a kind of light wave generated by mobile phones and other devices with screens, such as laptops, tablets, and televisions. Some blue light exposure can really be advantageous since it can help us stay alert. However, too much of it might be harmful to our brains.
Blue light can have a deleterious influence on the brain function in a variety of ways. For starters, blue light has been proven to inhibit melatonin synthesis, a hormone that helps regulate our sleep cycles. This implies that exposure to blue light before bedtime might make it considerably more difficult to fall asleep and sleep well. Inadequate sleep can impair the brain's focus, mood, response time, and memory. Blue light has also been found to raise cortisol levels, the stress hormone. This, along with sleep disruption, can result in feelings of worry and even sadness.
So, how do you shield your brain from blue light? You may prevent blue light on your phone by downloading applications or purchasing specific coverings to place on the phone screen. If you use spectacles, request that your optician apply a blue light filter to the lenses. You may also get non-prescription blue-light-blocking glasses.
It is critical to be aware of the hazards and make efforts to decrease your phone usage. Here are some suggestions for detoxing from your phone addiction while still protecting your brain.
Limit your screen time.
Limiting your screen time is one of the most effective methods to lower your chances of acquiring a phone addiction. Set aside specified times of the day when you are not permitted to use your phone. This might imply putting it away between meals or before going to bed. You might also try setting and sticking to a daily limit for yourself. Using an app like Rescue Time will allow you to see how much time you spend on your phone. Put yourself in command of your phone rather than the other way around.
Take breaks from your phone.
It's also crucial to take phone breaks throughout the day. This will assist you in avoiding getting overly dependent on it and will allow your brain to relax. Try searching for information in a book rather than on the internet, or solving a crossword puzzle rather than playing an online game.
Only use your phone for specific tasks.
When you do use your phone, make an effort to be deliberate about it. Use it for specific activities and then put it away when finished. This will prevent you from wasting time reading through social media or playing games when you could be doing something else. This will be made easier if you delete social media from your phone. You must then log into your laptop to check it.
Be mindful of your phone usage.
It's also critical to be aware of how you're using your phone. Are you utilizing it to remain in touch with loved ones or escape your life? If you find yourself using your phone in harmful ways, it may be time to reduce your usage. Rather than communicating with your friends and family over social media, go see them in person.
Mobile phones have a place in society and appear to be here to stay. However, you should be aware of how much time you spend on your phone. Although old age may seem far away, using your phone excessively when you are young might have major consequences for your brain's health. You've been forewarned!
- Screen time stats 2019: Here's how much you use your phone during the workday https://blog.rescuetime.com/screen-time-stats-2018/
- Phone Separation Anxiety And Treatment https://advantagementalhealthcenter.com/phone-separation-anxiety-and-treatment/
- Scientists Study Nomophobia—Fear of Being without a Mobile Phone https://www.scientificamerican.com/article/scientists-study-nomophobia-mdash-fear-of-being-without-a-mobile-phone/
- Influence of Smartphone Use on Emotional, Cognitive and Educational Dimensions in University Students https://www.researchgate.net/publication/343697254_Influence_of_Smartphone_Use_on_Emotional_Cognitive_and_Educational_Dimensions_in_University_Students
- Is texting making you anxious? Here's what it means https://timesofindia.indiatimes.com/life-style/health-fitness/de-stress/is-texting-making-you-anxious-heres-what-it-means/articleshow/87736729.cms
- The Common Sense Census: media use by tweens And teens https://www.commonsensemedia.org/sites/default/files/research/report/2019-census-8-to-18-full-report-updated.pdf
- The Mental Health Benefits of Exercise https://www.helpguide.org/articles/healthy-living/the-mental-health-benefits-of-exercise.htm
- Impact of Smartphones on Society https://bit.ly/3CpbUNw
- Ground-breaking study examines effects of screen time on kids https://www.cbsnews.com/news/groundbreaking-study-examines-effects-of-screen-time-on-kids-60-minutes/
- Brain Drain: The Mere Presence of One's Own Smartphone Reduces Available Cognitive Capacity https://www.journals.uchicago.edu/doi/full/10.1086/691462
- The brain in your pocket: Evidence that Smartphones are used to supplant thinking https://bit.ly/3E7l56v
- The FOMO Is Real: How Social Media Increases Depression and Loneliness https://www.healthline.com/health-news/social-media-use-increases-depression-and-loneliness
- The role of online social networking on deliberate self-harm and suicidality in adolescents: A systematized review of literature https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6278213/
- Does Social Media Use Increase Depressive Symptoms? A Reverse Causation Perspective https://www.frontiersin.org/articles/10.3389/fpsyt.2021.641934/full
- Blue light has a dark side https://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side
- What Lack of Sleep Does to Your Mind https://www.webmd.com/sleep-disorders/features/emotions-cognitive
- The Effects of Red and Blue Lights on Circadian Variations in Cortisol, Alpha Amylase, and Melatonin https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2905913/
- What are Sleep Disorders? https://www.psychiatry.org/patients-families/sleep-disorders/what-are-sleep-disorders
- 5 apps which help reduce the harmful blue light that emanates from smartphones https://www.digitalinformationworld.com/2018/08/applications-which-help-reduce-harmful.html
- Best Blue-Light-Blocking Screen Protectors https://www.healthline.com/health/best-blue-light-screen-protectors
- 8 Best Blue Light Glasses of 2022, Tested by Health Experts https://www.goodhousekeeping.com/health/a20707076/blue-light-glasses/
- https://www.rescuetime.com/mobile
The post Why Is Your Phone Harming Your Brain? appeared first on https://gqcentral.co.uk


text: Technical Support Frequently Asked Questions Licensing and Installation Graphing Data Analysis Data Handling Miscellaneous Programming Licensing and Installation What should I do if my Origin crashes? Is there a Mac Version of Origin? What should I do if double-clicking on my OPJ file fails to launch Origin? How can I install Origin on my Mac with WineBottler installed? Read More >> Graphing How do I insert Greek symbols and other special characters in a graph label? How do I add a second nonlinear x or y axis to my graph layer? How to insert greek symbols and subscript in plot legend and axis titles from worksheet headers? What to do if the color printer only prints black? How do I create a double Y axis graph? Read More >> Data Analysis How do I calculate the FWHM? How to compute EC50/IC50 in Dose Response fitting How do I find the area under my curve? How do I know if my fit result is good? How do I perform Peak Deconvolution? Read More >> Data Handling Are Origin project files (OPJ) forward- and backward-compatible? What are the different methods to calculate average value in Origin? How do I find the minimum or maximum value in a dataset? How to enable rich text for worksheet header rows? How can I recover a damaged Origin file? Read More >> Miscellaneous How do I solve Origin display problem in high resolution screen? How do I turn off the collapsible menus and show full menus? How do I reset my graph or worksheet template to default settings? Why are the Plot Setup dialog box or Theme Gallery not opening? Why the exported EPS file cannot be opened in Photoshop or Illustrator? Read More >> Programming How do I delete every nth row or column from my worksheet? How do I modify the legend? How to run Origin from command line? How can I run Python in Origin? How do I create custom toolbar buttons that run my script macros? Read More >>


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Building the City from the Inside
Architecture and Urban Transformation in Los Angeles, Porto, and Las Vegas
Time: Thu 2020-03-12 14.00
Location: F3, Lindstedsvägen 26, Stockholm (English)
Subject area: Architecture, Urban Design
Doctoral student: Hannes Frykholm , Stadsbyggnad
Opponent: Professor Albena Yaneva, University of Manchester, UK
Supervisor: Docent Daniel Koch, Stadsbyggnad, Arkitekturskolan; Associate Professor Catharina Gabrielsson, Stadsbyggnad; Professor Roemer van Toorn, Umeå universitet
Positioned in the research field of "interior urbanism" (Rice, 2016), this thesis considers entrance situations that occur between buildings and cities in order to develop new ways of investigating the relationship between architecture and urban transformation. From the main research question—How does architecture mediate urban transformation?—the thesis focuses on experience-driven narratives about the city (Pine & Gilmore, 2011). Looking at the means by which architecture situates the subject in an urban experience, the thesis asks how the experience contributes to a particular attention to the city. This approach intends to shed light on architecture's role in both mediating and challenging neoliberal urbanism (Peck, Theodore, & Brenner, 2009; Fraser, 2019). The thesis argues for analyzing large-scale processes of urban transformation by placing a sharpened empirical focus on the built environment. This is tested by a transversal research method (Frichot, Gabrielsson, Havik, & Jobst, forthcoming) that intersects multiple investigative techniques.
The three cases that are addressed—the Westin Bonaventure Hotel in Los Angeles, the Casa da Música in Porto, and Wynn Casino in Las Vegas—each epitomize a particular discourse about architecture and urbanization. Through observations and the analysis of the three cases, the thesis unpacks three dimensions of architectural experience of the city: first, by highlighting the spatial logic of a stretched threshold; second, by considering temporality and ways of waiting; and third, by observing the labor that is necessary to keep the interior environment intact. A recurring narrative in these buildings lies in the suggestion that the process of urban redevelopment never ends. Together, the cases point to an oft-overlooked parallel between the refurbishment of building interiors and exterior urban transformations, adding empirical nuances to what has been labelled the "architecture of neoliberalism" (Spencer, 2016). The threshold between building and city is shown to be a fragile and unstable territory, which is under continuous negotiation and where the claims of multiple actors, conditions, and events come together.
The thesis attempts to make a contribution in three ways: by developing transversal methods, by considering the threshold as knowledge device, and by exploring micro-scale investigations of urban transformation. The project points to how the stretched threshold of these projects speak of a transforming relationship between architecture and capitalism, where the city is reconfigured through the stretching of interiors out to adjacent sidewalks and squares. If the city is built from the expanding insides of architecture, the city is by definition an unfinished project. To think of the instability of architecture not as a shortcoming but as a virtue opens up for a continuous engagement with the city as the unfinished construction site of a democratic project.


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Scaling OSPF and IS-IS
- SPF Enhancements
- Flooding Enhancements
- Fragmentation
- Overloading
- Review Questions
Scalable may well be one of the most overused words in the network designer's lexicon. It applies to protocols, to software, to operating systems, to hardware architecture, and to networks. Scalable means, simply enough, the ability of the relevant entity (select one from the list just given) to get much bigger than it presently is without reducing performance, stability, or accuracy; making your customers angry; or getting you fired.
You have already encountered in this book a number of features that make OSPF and IS-IS scalable from the smallest to the largest networks. The most prominent feature for both protocols is areas. By dividing a network into multiple areas, you can control in each area the scope of flooding, the size of the link state database, and the complexity of the SPF calculations. By bounding these three fundamental link state functions, you constrain the demand OSPF and IS-IS put on router memory, router processing cycles, and link bandwidth, respectively.
You have also encountered features or extensions that can increase scalability, such as configurable refresh timers and increased metric sizes. This chapter delves further into features and extensions that can increase the scalability of the protocols.
8.1 SPF Enhancements
Chapter 2 gave you an idea of how an SPF algorithm works. And while that overview is enough to give you an understanding of the SPF algorithm, it is too simplistic for a practical link state protocol implementation. In fact, even if you follow the OSPF and IS-IS standards, you will get an implementation that is workable (if naïve) for small networks, but that lacks the stability, scalability, and accuracy necessary to survive in large-scale networks. For router vendors wanting to market to the largest network operators, sophisticated OSPF and IS-IS implementations are essential. Demonstrably robust implementations are a competitive advantage, and as a result, many of the enhancements to the SPF algorithm—and in fact the SPF algorithm itself—can be closely guarded corporate secrets. Therefore, it is impossible to detail many vendor-specific enhancements, but the general areas of enhancement can be examined.
8.1.1 Equal-Cost Multipath
The basic Dijkstra calculation described in Chapter 2 uses the following steps:
The router adds itself to the tree database as the root of the tree. It shows itself as its own neighbor, with a cost of 0.
All entries in the link state database describing links from the root to its neighbors are added to the candidate database.
The cost from the root to each node in the candidate database is calculated. The link in the candidate database with the lowest cost is moved to the tree database, along with the cost from the root. If two or more links are an equally low cost from the root, choose one. If any entries are left in the candidate database with a link to the neighbor just moved to the tree, those entries are deleted from the candidate database.
The router ID of the neighbor on the link just added to the tree is examined. Entries originated by that neighbor are added to the candidate database, except for entries in which the ID of the neighbor is already in the tree database.
If entries remain in the candidate database, return to Step 3. If the candidate database is empty, terminate the calculation. At this time, every router in the network should be represented as a neighbor on one of the links in the tree database, and every router should be represented just once.
However, there is an inefficiency in Step 3. Namely, "If two or more links are an equally low cost from the root, choose one. If any entries are left in the candidate database with a link to the neighbor just moved to the tree, those entries are deleted from the candidate database." An example is needed to understand why this is an inefficiency. Figure 8.1 shows a small network and its link state database. What is important about this network is that unlike the network in Figure 2.15 that was used for the SPF example in that chapter, all of the links in this network have the same cost. This example will show the SPF calculation at R1.
Steps 1 and 2 are shown in Figure 8.2. R1 adds itself to the tree database, the links to its neighbors are added to the candidate database, and the costs from the root to the destination nodes are calculated.
Figure 8.1 All links in this network have a cost of 2.
Figure 8.2 The links from R1 to its neighbors are added to the candidate database.
Step 3 is performed in Figure 8.3. The costs to the root are equal, so one of the entries is randomly chosen and moved from the candidate database to the tree database. The inefficiency in Step 3 will not be apparent until the end of the SPF calculation.
Figure 8.3 The link from R1 to R2 is moved to the tree database.
Step 4 is performed in Figure 8.4. R2 was added to the tree database, so all the links from R2 to its neighbors are examined in the link state database. R1 is already in the tree database, so only the link from R2 to R4 is added to the candidate database. The cost from the root to R4 is 4.
Figure 8.4 The link from R2 to R4 is added to the candidate database.
There are entries remaining in the candidate database, so, as Step 5 prescribes, Figure 8.5 shows a return to Step 3. The cost to root associated with the R1-R3 link is the lowest, so that link is moved from the candidate database to the tree database.
Figure 8.5 The R1-R3 link is moved to the tree database.
With R3 added to the database, the links to its neighbors are examined in the link state database. R1 is already in the tree database, so only the R3-R4 link is added to the candidate database in Figure 8.6. The cost from the root to R4 is 4.
Figure 8.6 The R3-R4 link is added to the candidate database.
In Figure 8.7, the cost from the root of both entries in the candidate database is 4, so one (R2-R4) is randomly chosen and moved to the tree database.
Figure 8.7 The R2-R4 link is moved to the tree database.
In Figure 8.8, the link state database is examined for R4's links to its neighbors: There are two, R4-R2 and R4-R3. However, both R2 and R3 are already in the tree database, so there are no new entries to add to the candidate database. But there is still an entry in the candidate database, and Step 5 says the SPF calculation stops only when the candidate database is empty. This is the reason for the part of Step 3 that says, "If any entries are left in the candidate database with a link to the neighbor just moved to the tree, those entries are deleted from the candidate database." If the "leftover" entries in the candidate database are not removed, the SPF calculation cannot end.
But the inefficiency of this rule also reveals itself at this point. If multiple equal-cost paths exist, choosing only one of the paths means all traffic will be routed on that path, possibly congesting it, while other equally good paths are ignored. We can modify Step 3 so that if there are multiple links in the candidate database to the same node and equally low cost, all the links can be moved from the candidate database to the tree database. In Figure 8.9, moving the R3-R4 link to the tree database empties the candidate database so that the SPF can stop. An enhancement to the router's forwarding processes can then be made that takes advantage of these multiple equal-cost paths by spreading traffic across all of them. This is equal-cost multipath (ECMP), or load balancing.1
Figure 8.8 The R3-R4 link remains on the candidate database and must be removed before the SPF calculation can end.
Figure 8.9 By moving the R3-R4 link to the tree database rather than just deleting it from the candidate database, an SPF tree is created in which two equal-cost paths from R1 to R4 exist.
Figure 8.10 shows one situation in which ECMP can apply. In this topology, the next hop from Router A to subnet 10.1.1.0 is Router B. But there are three links to Router B, each with a cost of 50. Router A can balance the traffic going to 10.1.1.0—and any other destination for which Router B is the next hop—across the three links.
Figure 8.10 ECMP allows Router A to utilize all three links to Router B for traffic going to subnet 10.1.1.0.
Figure 8.11 shows another application of ECMP. Here, Router A has two next hops—Router B and Router C—to subnet 10.2.2.0. Routes to the destination through either next hop have the same cost because all four of the links shown have the same cost. So in this case, Router A can select both next hops and balance the traffic to 10.2.2.0—and any other traffic to destinations that pass through Router D—between Routers B and C.
Figure 8.11 ECMP allows Router A to use two equal-cost routes to subnet 10.2.2.0.
Given multiple equal-cost paths—either to the same next-hop router as in Figure 8.10 or through separate next-hop routers as in Figure 8.11—a router can balance traffic across them in several ways. One approach is per-packet load balancing, in which the router forwards packets round-robin or randomly over each path as shown in Figure 8.12. The problem with this approach is that different links, although of equal cost, might not be of equal delay. Link propagation, router latency and buffering, and link MTUs requiring fragmentation might differ from one path to another. As a result, packets can become reordered at the receiving end. This can cause problems for TCP, which when it sees out-of-sequence packets can request retransmits. The result is reduced performance and wasted bandwidth.
Figure 8.12 Per-packet load balancing distributes packets individually over equal-cost paths.
A better approach is per-destination load balancing, in which packets are distributed across multiple paths by destination, as shown in Figure 8.13. In this example, Router A knows it has two equal-cost paths to the destinations 10.1.1.0 and 10.2.2.0. It chooses Router B as the next hop for the route to 10.1.1.0, and Router C for the route to 10.2.2.0. As Router A discovers more routes to destinations reachable through Router D, it continues to alternately assign Router B and Router C as next hops. The functional difference is that per-packet load balancing assigns all ECMP next hops to each route, whereas per-destination load balancing selects, either round-robin or randomly, one next hop from the set of ECMP next hops for each route.
Although per-destination load balancing is an improvement over per-packet, it is still not very good. If substantially more packets are sent to one destination than to another, the overall bandwidth utilization will be uneven. For example, suppose Router E in Figure 8.14 is providing Internet access. When it advertises BGP routes to the other routers in the figure, the routes are given a next-hop address of 10.255.0.1, Router E's loopback address. This is common practice; Router E is advertising that it is the next hop for any Internet destinations. When Router A receives these BGP advertisements, it does a lookup of 10.255.0.1 in its IGP routes to find out how to reach the BGP next hop. If the router is performing per-destination load balancing, it selects either Router B or Router C as the "next hop to the next hop"—that is, the IGP next hop to the BGP next hop. The potential problem is that if traffic passing through Router A to the Internet is relatively heavy compared to other traffic passing through Router A to Router D, the loading across the equal cost paths can be severely unbalanced.
Figure 8.13 Per-destination load balancing distributes next hops or outgoing interfaces among multiple equal-cost routes.
Figure 8.14 Per-destination load balancing might be inefficient in this topology.
Per-flow load balancing improves the traffic distribution by identifying individual traffic flows and forwarding all packets belonging to the flow to the same next hop or out the same interface. At a minimum, a flow might be defined as all packets with the same source and destination addresses. However, flows can be made more granular by defining a flow not only by source and destination address but also by protocol number, source and destination port,2 and perhaps ToS or DSCP (differentiated services code point) values. When a packet is to be forwarded, the values of these fields become the input to a hashing algorithm. (Router vendors define their own hashing algorithms.) The packet is then associated with a flow based on the resulting hash value, and all packets belonging to the same flow are forwarded to the same next hop.
8.1.2 Pseudonodes and ECMP
If some but not all of the links in an ECMP group are broadcast links, a subtle problem can arise from simplistic SPF implementations. Another example SPF run will help you understand the problem.
The physical topology in Figure 8.15 shows two routers, R1 and R2, interconnected with both a point-to-point link and an Ethernet link. The outgoing cost on both of R1's interfaces is 2, so the two links comprise equal cost paths, and load balancing can be performed between R1 and R2. The logical topology shows that the Ethernet link is represented as a pseudonode, which is labeled in this example as P3. Recall from the discussion of pseudonode basics in Section 4.4 that the cost from a pseudonode to any of its attached routers is 0, so that the pseudonode does not affect the transit cost of the broadcast link. Figure 8.16 shows the start of the SPF calculation at R1 for this small network, in which R1 installs itself in the tree database as the root and then adds all links to its neighbors to the candidate database.
The two links added to the candidate database are of equal cost (2) to the root, so as in previous examples, one is chosen at random and added to the tree database (Figure 8.17). In this case, the chosen link is R1-R2. Although not yet apparent, this random choice will cause a problem with ECMP.
Figure 8.15 There are two equal-cost paths between R1 and R2, one of which is point-to-point and one of which is broadcast.
Figure 8.16 R1 installs itself as root and adds the links to its neighbors to the candidate database.
Figure 8.17 The R1-R2 and R1-P3 links are of equal cost from the root, so one is randomly chosen to move to the tree database.
Because a link to R2 was added to the tree, the links to R2's neighbors are examined in the link state database (Figure 8.18). There are two, R2-R1 and R2-P3. R1 is already in the tree database, so only the R2-P3 link is added to the candidate database.
Figure 8.18 A link to R2 was added to the tree database in the last step, so the R2-P3 link is added to the candidate database.
In Figure 8.19, R1-P3 has the lowest cost from the root and so is moved to the tree database. Because there is now a path to P3 in the tree database, the higher-cost R2-P3 link is deleted from the candidate database.
Figure 8.19 The lower-cost R1-P3 link is moved to the tree database and the higher-cost R2-P3 link is deleted from the candidate database.
With P3 added to the tree, its links to its neighbors are examined in the link state database. There are two, P3-R1 and P3-R2. But both R1 and R2 are already on the tree, so neither of these links is moved to the candidate database. At this point, the candidate database is empty, so the SPF calculation stops. And now, in Figure 8.20, we can look at the resulting tree and see the ECMP problem. R1 has branches to R2 and to P3, each at cost of 2, but the tree does not include a branch from P3 to R2. Therefore, R1 forwards all traffic to R2 across the point-to-point link and none across the Ethernet link. No load balancing can take place.
As mentioned, the problem actually arose with the random selection in Figure 8.17 of the R1-R2 link from the candidate database. So let's back up to that step and select the other link instead. Figure 8.21 shows the candidate database in the same state as in Figure 8.17, but now R1-P3 is selected and moved to the tree database instead of R1-R2.
Figure 8.20 The resulting tree does not allow load balancing across the two equal-cost paths because it does not include a branch from P3 to R2.
Figure 8.21 Returning to the point in the SPF calculation where either R1-R2 or R1-P3 is randomly selected for the tree database, R1-P3 is now chosen instead of R1-R2 as in Figure 8.17.
Continuing on with the SPF calculation, because a link to P3 was added to the tree, the links to P3's neighbors are examined in the link state database. R1 is already on the tree, so only P3-R2 is added to the candidate database (Figure 8.22).
Figure 8.22 The P3-R2 link is added to the candidate database.
Now, in Figure 8.23, the candidate database contains two equal-cost entries for links to R2. Using the modification to the SPF algorithm described in Section 8.1.1 to accommodate ECMP, rather than randomly selecting one and discarding the other, both are moved to the tree database. No links remain in the link state database to nodes that are not already on the tree, and the candidate database is now empty, so SPF stops.
Figure 8.23 R1-R2 and P3-R2 are equal-cost links to the same node, so they are both moved to the tree database.
Figure 8.24 shows the resulting tree. Both equal-cost paths are now represented, and R1 can load balance traffic to R2. The significant step that prevented disruption of ECMP is that in Figure 8.21 the link to the pseudonode was selected for the tree database before the link to R2. Therefore, to ensure that ECMP works correctly when the ECMP group consists of a mixture of point-to-point and broadcast links, the following simple rule is added to the SPF procedure:
If there are multiple entries in the candidate database with equally low cost, and if at least one link is to a pseudonode and at least one link is to a router, always select the link to the pseudonode first rather than randomly selecting among the links.
Figure 8.24 The resulting tree correctly accounts for the two equal-cost paths, and so allows load balancing.
Specific OSPF or IS-IS implementations might or might not include this modification. So if load balancing is a part of your network design, be sure to verify with your vendor that their SPF routine includes this rule.
8.1.3 Incremental SPF Calculations
It is not difficult to find network engineers and operators who think distance vector protocols are preferable over link state for all but the largest networks. Ask them why, and their answer is "because the SPF calculations are complex and CPU intensive, and they will hurt my routers' performance." These folks are stuck in the nineties. Concern over the price in router resources needed to pay for SPF was partially justified a decade or so ago, but there is no longer reason to fear SPF (in relation to distance vector protocols, at least). Several factors contribute to this change in attitude:
Increased router performance and memory capacity
Increased sophistication of physical and logical router architectures
Increased base of experience designing and operating large, complex networks
Increased base of vendor experience designing sophisticated SPF processes
One of the improvements several router vendors have incorporated into their SPF procedures is Incremental SPF (iSPF). To understand iSPF, consider the network shown in Figure 8.25. Using the link costs given in the illustration, you can determine with little trouble that R1 will calculate the shortest-path tree shown in Figure 8.26.
Figure 8.25 An example network and link costs.
Figure 8.26 The shortest-path tree calculated by R1.
Now consider a change to the network topology. Figure 8.27 shows the addition of a new node, R8. The change to the tree to account for the new node is shown in Figure 8.28. With the SPF procedures as you have seen them so far, the addition of the new node requires the reflooding of LSAs or LSPs and a recalculation of SPF by all routers in the area. But a cursory look at the new topology shows that most of the tree has not changed; the addition of R8 involves the simple addition of a branch from R5.
Figure 8.27 Node R8 is added to the topology of Figure 8.25.
Figure 8.28 The new shortest-path tree from R1 shows the added router R8.
Consider another topological change, shown in Figure 8.29. Here, the link between R4 and R5 has failed or been disabled. Again, our understanding of SPF so far requires that this information be flooded throughout the area and that all nodes rerun SPF. But this link is not a part of the shortest-path tree shown in Figure 8.26, so rerunning SPF results in a tree that looks exactly the same as it did before the link failure.
Figure 8.29 Failure of the R4-R5 link does not change the shortest-path tree, because it was not a branch of the tree to begin with.
These two topological changes are the basis for iSPF. In the first example, in which a router with a single link to the network was added (that is, a stub router), there are no alternative links to consider and so no need to attempt to calculate a shortest path. There is only one path to the new node. Therefore, a full SPF run is unnecessary for the routers that were already on the tree; they only need to add the new branch from R5 to R8.
In the second example, the failure of the link has no affect whatsoever on the shortest-path tree and so again there is no need for the nodes in the area to rerun SPF. Only a reduction in the metrics associated with the R4-R5 link would necessitate a full SPF run.
iSPF takes into consideration topological changes, such as the two shown in this section, and performs SPF only to the extent necessary to allow for the changes. In the first case, a simple distance vector–like addition to the tree is required; in the second case, no action at all is required. Experience has shown that iSPF provides the greatest benefit in cases of the first example, when stub routers are added to or removed from the topology.
8.1.4 Partial Route Calculations
The topology changes described in the previous section are by no means unusual in an IGP-routed topology, so it is easy to understand how the changes to the basic SPF procedure incorporated by iSPF can improve efficiency. Another network change, as common as those of the previous section, is the addition, deletion, or metric change of IP addresses. Reviewing the basic SPF procedure, you can see that the only addresses used in the computation of the shortest-path tree are the RIDs. Although recording the distance and direction of IP prefixes from each router is the ultimate goal of any routing protocol, the prefixes themselves have no bearing on an SPF calculation; after the location and cost of each node on the shortest-path tree are determined, it should be a simple matter to record what prefixes are attached to or advertised by what node.
This is the basis of Partial Route Calculations (PRC). When a node advertises the addition, deletion, or metric change of an IP prefix, rather than unnecessarily rerunning the SPF calculation the other nodes on the tree simply record the change. Although a full SPF run in even large networks is very fast—a high-performance router should be able to process 500 to 1000 nodes in 50 to 100ms—PRC is substantially faster, ranging from 0.5 to 10ms depending on the number of prefixes to be scanned.
PRC's increased efficiency is more substantial in IS-IS than in OSPFv2 because of the way each protocol advertises IP prefixes. IS-IS advertises all IP prefixes in IP Reachability TLVs, whereas node information necessary for SPF calculations is advertised in IS Neighbors or IS Reachability TLVs. This clear separation of prefix information from topology information makes PRC easily applicable to any IP address change.
OSPFv2, on the other hand, incorporates IP address semantics into type 1 and type 2 LSAs. That is, routers or pseudonodes advertise both topological information and their attached IP addresses in the same LSAs. So for example, if an IP address attached to an OSPFv2 router changes, the router must originate a type 1 LSA to advertise the change. However, because node information is also carried in type 1 LSAs, flooding the LSA triggers a full SPF calculation in all routers in an area—even though the address change is irrelevant to the node topology. As a result, only type 3, 4, 5, and 7 LSAs—whose only purpose is to advertise prefix information—trigger a PRC in OSPFv2.
The applicability of PRC to all IP prefixes in an IS-IS domain, not just prefixes external to an area as in OSPFv2, is a significant contributing factor to the better scaling properties of IS-IS in a single area. You will see in Chapter 12 that OSPFv3 improves its scaling by removing addressing semantics from its Router and Network LSAs and using a new type of LSA to advertise attached prefixes.
8.1.5 SPF Delay
Although the kinds of network events that trigger iSPF and PRC are common, they are not necessarily frequent. In large networks, the kinds of address changes that trigger PRC happen only a few times a day, and the kinds of topological changes that trigger iSPF might happen only a few times a week. Moreover, a full SPF run in even a very large network takes only tens of milliseconds. Given these facts, the value of iSPF and PRC becomes evident mainly when abnormal things happen. But in a large area, LSAs or LSPs will flood regularly because of the random expiration of refresh timers around the network, requiring regular SPF runs. And when bad things happen, routers can become inundated with changing LSA/LSPs. If each LSA/LSP triggers a full or incremental SPF run, and if they are arriving fast and furious, SPF can begin eating up the majority of CPU cycles. Scheduler slips result, important tasks become delayed or completely missed, and the router can become seriously destabilized.
The challenge in large-scale networks, then, is to quickly react to network changes while at the same time not allowing SPF calculations to dominate the route processors. This is the goal of SPF delay, also called SPF holddown or SPF throttling. Rather than kick off an SPF calculation every time a new LSA/LSP arrives, SPF delay forces the router to wait a bit between SPF runs. If a large number of LSA/LSPs are being flooded, a delay between SPF runs means that more LSA/LSPs are added to the link state database during the holddown period. Efficiency is then increased because when the holddown period expires and SPF is run, more network changes are included in a single calculation.
SPF delay arguably adds another small efficiency. When an SPF calculation is being run, it is necessary to "freeze" the link state database so that new LSA/LSPs are not added.3 The reason for this is obvious: Changing the link state database in the middle of an SPF calculation could corrupt the results. So, all LSA/LSPs that arrive during a running SPF calculation must be buffered until the calculation ends, and only then added to the link state database (likely triggering another SPF run). SPF delay, by reducing the overall frequency of SPF runs, reduces the frequency that LSA/LSPs must be buffered.
Of course, the price you pay for delaying an SPF calculation is an increased network convergence time. So, the challenge when determining a delay interval is to make it long enough that a heavy surge of LSA/LSPs does not destabilize the router while still keeping it short enough that convergence is not hurt significantly. Even better would be to have normal "fast" SPF calculations when conditions in the network are normal, and delayed SPF calculations when the network is unstable. Several vendors do offer such adaptive SPF timers.
Juniper Networks uses a delay scheme in which the normal period between SPF runs is short. This period is 200ms by default, meaning an SPF run cannot take place any sooner than 200ms after the last run. The period is configurable with the spf-delay command to between 50 and 1000ms; the command can be used with both OSPF and IS-IS, and applies to both full and partial SPF calculations. If three SPF runs are triggered in quick succession, indicating instability in the network, the delay period is automatically changed to 5 seconds. This "slow mode" period is not configurable. The routers remain in this "slow mode" until 20 seconds have passed since the last SPF run—indicating that the network has stabilized—and then switches back to "fast mode."
Cisco Systems originally had a similar linear fast/slow algorithm (configured for OSPF with the command timers spf). But more recently, Cisco has taken a different approach to adaptive SPF delays by using an exponential backoff algorithm. Initial delay, delay increment, and maximum delay periods4 are configured. The router waits the initial delay period before first running SPF. After the first run, the delay is increased by doubling the delay increment every time SPF runs. So for example, if the initial delay is 100ms and the delay increment is 1000ms, the router delays the first SPF run by 100ms, the second by 1000ms, the third by 2000ms, the fourth by 4000ms, and so on. The maximum delay value specifies in seconds the largest value to which the delay can be incremented—an obvious necessity to prevent an unstable network from causing the SPF delay to increase so much that SPF does not run at all. When SPF has not run for twice the time specified by the maximum delay period, the router switches back to "fast" mode in which the initial delay period is used.
These three timers are specified for OSPF with the IOS command timers throttle spf and for full IS-IS SPF with the command spf-interval. Partial SPF for IS-IS is configured separately with the IOS command prc-interval.


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1994 report to Sri Lanka's National Committee for the International Decade of the World's Indigenous People
by Patrick Harrigan of Cultural Survival of Sri Lanka
Sri Lanka's indigenous inhabitants, the Veddas or Wanniya-laeto ('forest-dwellers') as they call themselves, preserve a direct line of descent from the island's original Neolithic community dating from at least 14,000 BC and probably far earlier according to current scientific opinion.1 Even today, the surviving Wanniya-laeto community retains much of its own distinctive cyclic worldview, prehistoric cultural memory, and time-tested knowledge of their semi-evergreen dry monsoon forest habitat that has enabled their ancestor-revering culture to meet the diverse challenges to their collective identity and survival. With the impending extinction of Wanniya-laeto culture, however, Sri Lanka and the world stand to lose a rich body of indigenous lore and living ecological wisdom that is urgently needed for the sustainable future of the rest of mankind.
Historically, for the past twenty-five centuries or more Sri Lanka's indigenous community has been buffeted by successive waves of immigration and colonization that began with the arrival of the Sinhalese from North India in the 5th century BC. Consequently, the Wanniyalaeto have repeatedly been forced to choose between two alternative survival strategies: either to be assimilated into other cultures or to retreat ever further into a shrinking forest habitat. In the course of history, uncounted thousands of these original inhabitants of the wanni (dry monsoon forest) have been more or less absorbed into mainstream Sinhala society (as in the North Central and Uva provinces) or Tamil society (as on the East Coast). Today only a few remaining Wanniya-laeto still manage to preserve their cultural identity and traditional lifestyle despite relentless pressure from the surrounding dominant communities.
While the shy, retiring nature of the Wanniyalaeto has served to insulate them from the contaminating effects of contact with mainstream society, it has also effectively precluded their fair and adequate representation in the democratic decision-making process. Whenever a conflict of interests has arisen between the nomadic hunter-gatherer Wanniyalaeto community and the far larger dominant community of settled agriculturists and traders, the dominant community has invariably ignored the interests of the Wanniyalaeto.
Early Sinhala immigrants from North India were of the opinion that the forest-dwelling aboriginal were not human beings at all but wild jungle spirits (yakas) who were human in outward guise only. Such negative, stereotyped attitudes towards the island's indigenous people persists up to the present day even in educated circles and has been a major stumbling block to the recognition of Wanniya-laeto self-respect, dignity, human rights, and cultural uniqueness. Hence, the Wanniyalaeto are widely assumed to be a backward, gullible people whose point of view may be conveniently ignored.
The vulnerable position of the Wanniyalaeto vis-a-vis mainstream society may be said to stem from two principal causes. One is that they have never received secure land tenure that recognizes their collective custodianship over traditional hunting and gathering ranges. The other reason is that they have never been consulted or represented in the decision-making process that affects their daily lives. Given the secure right to manage their traditional habitat according to their ways and given a voice to represent their collective aspirations within the framework of society at large, the Wanniyalaeto are more than capable of preserving both their endangered forest habitat and their ancestral culture for the benefit of all.
The Wanniya-laeto themselves operate within a radically different conceptual framework from that of the local administrators who wield power over Wanniyalaeto land and interests. For instance, the Wanniyalaeto do not entertain modern notions of real estate belonging to individuals, but believe that they and their ancestor-spirits belong to the forests of the Wanni which they inhabit and protect. Likewise, the concept of acreage is strange to them since they recognize only natural landmarks like hills, rivers, and villages. As a consequence of such cultural differences, the Wanniyalaeto have been repeatedly swindled out of their ancestral heritage by contrary interests anxious to seize control over Wanniya-laeto lands and forest resources. Such encroachment and economic exploitation has noticeably accelerated in the post-Independence era.
Similarly, modern observers have typically been blind to the basic facts about indigenous culture. For instance, Wanniyalaeto social structure is a matrilineal exogamous clan organization based on female line of descent.2 In simple terms, the Wanniyalaeto are a forest people who trace their ancestry through their mother's line back to their mother-ancestor, the yaka-princess Kuveni.
This self-identification of the Wanniya-laeto differs radically from the definition of a 'Vedda' ('hunter') that was imposed upon them from outside with far-reaching social consequences. Hence, to colonial census-takers and other outsiders, a 'Vedda' was a primitive human-type of wild disheveled appearance, uncouth language and appearance, who resides in caves or wanders in the jungle, and who subsists by primitive means such as hunting with bow and arrows.
Thus, by these misleading criteria, the 'Veddas' (a term never used by the Wanniya-laeto themselves) were doomed to disappear in the course of time. Indeed, according to census records the Veddah population actually fell from 4,510 in 1921 to 2,361 in 1946 while since 1963 no separate count has been made, although a 1978 study identified six thousand Veddas in the Anuradhapura district alone. 3
This failure to recognize the Wanniya-laeto people's own criteria of self-identification. Whether intentional or not, it has effectively accelerated their disappearance as a distinct culture and denied them representation in the democratic decision-making process.
As a result of pervasive social discrimination directed against the Wanniya-laeto, many of their people have adopted a survival strategy that includes taking Sinhala or Tamil names for themselves and their children, adopting the prevalent language, diet, dress, and lifestyle patterns and becoming, nominally at least, Buddhist or Hindu converts. And yet, because their matrilineal ancestry goes unnoticed and unrecognized by the dominant patrilineal society at large, the Wanniya-laeto have been able to preserve their social cohesion and cultural self-identification even while immersed within the outward trappings of cultures very much unlike their own.
A field study conducted in 1992 by a specialist in indigenous development policy from the International Labour Organisation succinctly summarized the plight of the Veddas (Wanniya-laeto) with respect to current development policy in Sri Lanka: According to the existing studies, the majority of the resettled Veddas are economically backward, socially isolated, and politically marginalised. The Veddas did not have the skills, means and knowledge needed to either adjust to the new situation (no knowledge of capital accumulation or savings, no familiarity with the monetary system of exchange, no long-term involvement in agriculture as a livelihood, lack of incentive for competitive tasks, etc.), or to cope with the other non-Vedda settlers. As a result, they are being exploited by the other settlers who have control over the local political institutions and economic opportunities; in several cases attempts to get the Veddas used to seasonal paddy cultivation have failed, thus worsening severely their livelihood since they do not resort any longer to hunting or food gathering. It has been pointed out that tribal peoples have suffered from depression and loss of confidence as a consequence of factors such as loss of land, loss of freedom of the forest and disappearance of ritual hunts as the causes of their demoralization. The situation has not changed substantially even after national authorities recognized the Veddas' desire to preserve their cults and customs and to be resettled in close proximity to their traditional lands. 4
The same study traces the wholesale disruption brought upon Wanniyalaeto culture due to 20th-century development activities:
The drastic changes in the number, distribution and social organisation of the Veddas started in the 1930s and 1940s when large irrigation and colonization schemes in the Polonnaruwa and Mahiyangana regions were launched. These projects brought a massive influx of Sinhalese and Tamil colonists and a reduction of the forestland that was homeland to the Veddas. In the 1950s when the Gal Oya scheme was completed, access of the Veddas to their ancestral lands and their means of livelihood were eroded even more drastically.5
The Sri Lanka government's concern for its indigenous people dates back to the early 1950s when a Vedda Welfare Committee was created as part of a Backward Communities Development Board. During this period, the prevalent philosophy of development regarded the disappearance of indigenous and tribal peoples as distinct societies as an irreversible and desirable process. Seen as backward and irrational, they were regarded as obstacles to national development and growth. Needless to say, such indigenous and tribal peoples as the Wanniyalaeto were not consulted for their views on the subject.
In recent years, however, the way of viewing the relationship between culture and development has undergone changes. Even during the 1960s and 70s, culture was considered to be irrelevant to the development process and much of the blame for failed development projects was attributed to resistance to modernization from affected traditional communities. Later, culture came to be regarded as inviolable and, as such, development was to be discouraged and enforced isolation was advocated. But this strategy also is inadequate to enable endangered cultures to cope with social change.
More recently, culture has come to be regarded both as a goal and as a framework within which to promote other development goals.6 This means that it is up to the affected people to decide how and to what extent to retain their cultural values and ways of life, and that any development initiative should bear these values in mind. Like all societies, indigenous cultures are subject to change, too.
Accelerated Development
In 1977 the Accelerated Mahaweli Development Scheme was launched, under which vast tracts of traditional Wanniyalaeto hunting lands were alienated for the proposed benefit of other communities. As usual, the offering of equitable compensation to the region's displaced indigenous inhabitants was not even considered. Every major decision was taken either in far-off Colombo or in distant foreign capitals without consulting the region's indigenous people.
Under the Accelerated Mahaweli Development Scheme, vast extents of forestland have been logged and inundated or earmarked for colonization. One last Wanniyalaeto hunting domain remained upon 145,450 acres of forest between the western chain of reservoirs and the Maduru Oya irrigation dam, but this too was on November 9th, 1983, declared to be the Maduru Oya National Park. It was intended as a habitat for displaced wildlife and as a protected catchment area: But under the terms of the Fauna and Flora Ordinance, "No person shall be entitled to enter any National Park, except for the purpose of observing the fauna and flora therein", and "no animal shall be hunted, killed and taken and no plant shall be damaged, collected, or destroyed in a National Park." Entry can be allowed only under "the authority and in accordance with the conditions of a permit issued by the prescribed officer on payment of the prescribed fee", and only to allow the permit-holder to observe fauna and flora.
Consequently, the Wanniya-laeto, who had been occupational hunter- gatherers and custodians of the forest for uncounted millennia, were transformed overnight into game poachers and trespassers. Barriers, guards, and outposts were stationed along the park's demarcated borders and the hapless Wanniyalaeto were evacuated to "rehabilitation" villages in Systems C and B of the Accelerated Mahaweli Development Scheme where they were to become rice cultivators (see Map of Mahaweli Development Scheme settlements). As one translocated Wanniyalaeto leader later observed, "The government took away our hunting tools and gave us mammoties to dig our own graves."
The old Wanniyalaeto chieftain Uru Warige Tissagami (popularly known as Tissashamy) and his kinsfolk of Kotabakinni, however, refused to be evicted from the land of their ancestors. Officials considered him to be very obstinate and stubborn, for he would not budge an inch no matter how many emissaries came to "talk sense" to him. Finally the government had to concede that these seven families could remain as long as the old man lives. However, according to the 1987 Master Plan for Maduru Oya National Park, the day that aged chief Tissahamy expires, the rest his kinsfolk will have to evacuate the hamlet immediately.7 Knowing this, Tissahamy even refused to die (note: Tissahamy finally expired in June 1999 at the age of 96).
Wanniyalaeto leaders allege that since 1974 they have listened to official assurances that a sanctuary of 1,800-acre extent will be created for them to pursue their traditional way of life. Successive governments have repeated this pledge, but to date still no government has implemented its pledge. Even this modest figure (amounting to only one percent of the park's area) was originally cited not as a sanctuary for all affected Wanniyalaeto, but only as a buffer zone to prohibit commercial logging activities around Tissahamy's hamlet of Kotabakinni only.
In fact, the other affected hamlets cannot possibly be included in a sanctuary of this size, which is sufficient to sustain a few families by their traditional means of livelihood. But the 1,8OO-acre figure has remained to be seized upon by officials and even, years later, by Tissahamy's attorney, resulting in further tensions and misunderstandings.
However disadvantaged the island's indigenous forest-dwellers may appear to be in the eyes of modern-educated observers, nevertheless their sense of honour, justice, and fair play is very keen. Despite centuries of injustice and exploitation by economic predators from outside communities, even to this day the Wanniyalaeto people remain so gentle and patient towards younger cultures that, although they are proficient hunters, they have never been known to raise a weapon in anger, to commit theft or fraud out of greed, or even to raise their voice toward outsiders, let alone to speak any untruth for personal gain. Indeed, these are precisely the elements of their cultural heritage that the Wanniyalaeto are most anxious to preserve for future generations. Colonised Wanniyalaeto are deeply dismayed by the corruption of their culture caused by forced assimilation into a modern society which they regard, justifiably, with utter contempt.
Human Rights
In the absence of any provision for direct representation of indigenous interests in official decision-making, the Wanniyalaeto have explored other potential avenues to achieve justice, including a court system that is completely alien to their own tradition of justice. Going still further, chief Tissagami and other Wanniyalaeto leaders have been granted sympathetic hearings by Presidents Jayewardena and Premadasa respectively and by other high-ranking officials who have promised to rectify injustices, but resistance to change within the government bureaucracy has effectively stifled every high-level initiative designed to respect Wanniyalaeto aspirations.
Over the years, scientific interest in the millennia-old Wanniya-laeto culture has helped to bring their plight to international notice. In particular, one Swedish cultural anthropologist, Dr. Wiveca Stegeborn, has been closely associated with the Wanniyalaeto community of Dambana since 1977, even to the extent of learning their language and living among them as one of their people. With her professional training and close familiarity with the kinds of problems that the Wanniyalaeto have faced in recent years, Dr. Stegeborn has played an invaluable, if little-appreciated, role in garnering international sympathy and support for the Wanniyalaeto community.
With Dr. Stegeborn serving as their intermediary and patron, the Wanniyalaeto were invited to come to Geneva in 1985 to submit testimony before the United Nations Working Group on Indigenous Populations Commission on Human Rights, Sub-Commission on Prevention of Discrimination and Protection of Minorities. But the three Wanniyalaeto delegates were unable to attend because officials of the Sri Lanka Government's Department of Immigration and Emigration refused to issue passports to them. One of the reasons offered for the refusal of passports was that the Wanniyalaeto were "not real Sri Lankans".8 Subsequently, Dr. Stegeborn was declared persona non grata, further obstructing efforts to redress social injustice.
Wanniyalaeto people say that they are still prohibited from pursuing their ancestral livelihood and face harassment or arrest by wildlife officials if they are caught 'trespassing' outside of their tiny enclaves. Tribal leaders accuse the armed forest officers of intimidation and allege that only recently the same officers were responsible for the shooting deaths of three Wanniyalaeto clansmen.9 To date, however, no investigation of the incident has been made.
Wanniyalaeto Sanctuary
On June 16th, 1990, President Premadasa and other high-level officials met in Kandy with a delegation of Wanniyalaeto leaders including chief Tissahamy to discuss longstanding grievances and measures required to address these grievances. Following the meeting, President Premadasa ordered prompt steps to be taken to reverse years of official injustice towards the indigenous community. Three days later, the President's Minister for Lands, Irrigation and Mahaweli Development, Mr. P. Dayaratna, recommended and later received Cabinet approval for the following two-fold course of action:
(i) Demarcate an area of approximately 1500 acres (covering Kotabakiniya, Keragoda, Buluganhadena and Kandeganwila villages), from the area gazetted as the Maduru Oya National Park, and declare this area as a Sanctuary under the Fauna and Flora Protection Ordinance.
(ii) Take specific measures to protect and nurture 'Vedda Wanni-etto' culture and establish a Trust or a Board for this purpose under the chairmanship of the Director of Wildlife Conservation with representation from the Ministry of Cultural Affairs and other relevant state agencies and non-governmental organizations. 10
Under the Fauna and Flora Protection Ordinance, all traditional Wanniyalaeto occupations including hunting, honey-gathering and chena cultivation are prohibited within national parks, but 'limited human activities' are permitted within other areas defined as 'sanctuaries'. However, the four aforementioned Wanniyalaeto hamlets cannot be encompassed within 1500 acres only, nor can 1500 acres sustain more than a few families living by hunting and gathering supplemented by shifting cultivation. Moreover, no provision is included to accommodate families of evacuees who wish to return to their former habitat.
Wannietto Trust
As of early 1993, section (i) of the 1990 Cabinet order has yet to be implemented. Regarding section (ii), sixteen months passed before officials from other concerned ministries and NGOs (including Cultural Survival) were invited to serve on the Board of the proposed Wannietto Trust, and another five months passed before the first meeting was actually held in April, 1992. In four meetings to date, the Trust has accomplished very little in concrete terms "to protect and nurture" Wanniyalaeto culture.
Its meeting of March 4th, 1993, appeared to have marked a watershed, however, with the long-overdue nomination of the first (university-educated) Wanniyalaeto representative to join as a full member of the Board and with the recognition at long last among Board members of the urgent need to implement section (i) of the 1990 Cabinet order. But first officials must resolve ambiguities regarding the boundaries of the Wanniyalaeto sanctuary.
The Wannietto Trust has been further hamstrung by the lack of any office facility and complete absence of any government funding, even to photocopy documents or to hire a paid secretary, fueling speculation that the Trust was created as a mere political eyewash. Since its creation, the Trust has relied almost entirely upon the NGO Cultural Survival of Sri Lanka to provide it with supporting documentation and liaison with Wanniyalaeto leaders and with concerned international agencies like the International Labour Organisation and others. This dependency has also put strains upon Cultural Survival's resources.
The present context of 1993 as the International Year for the World's Indigenous People has provided an opportunity to draw greater public and official notice to the plight of the Wanniyalaeto, but so far its effect has been cosmetic only. Since creation of the Maduru Oya National Park, the living standards, nutrition and morale of the Wanniyalaeto have markedly deteriorated. Meanwhile, plans are afoot to open the park not to Wanniyalaeto but to tourists willing to pay stiff entry fees. Tour operators have already been driving their clients up to the very doorstep of Wanniyalaeto hamlets to entertain them with sights of 'the last Veddas', even against the inhabitants' expressed wish to the contrary. Further violations of Wanniyalaeto cultural norms will surely hasten the final demise of their ancient culture.
Meanwhile, Sri Lanka has been elected to the UN Commission on Sustainable Development that was established "to oversee, coordinate, monitor, review and report on the implementation of Agenda 21", but in Sri Lanka little is being done to ratify — let alone implement — international protocols such as Agenda 21 and ILO Convention No.169 that concern the rights of indigenous people like the Wanniyalaeto. Still no mechanism exists for regular consultation between Wanniyalaeto leaders and government officials, while many privately fear that the government is only waiting for old chief Tissahamy to expire before plowing through with an agenda more attractive to private interests.
- "Pre-Anuradhapura civilisation discovered", Colombo: The Sunday Island, 3 January 1993.
- Seligmann, C.G. "Notes on Recent Work Among the Veddas". Journal of the Royal Asiatic Society (Ceylon), Vol. XXI No. 61 (1908), p. 74.
- Brown, J. Veddha Villages of Anuradhapura: The Anthropological History of a Community in Sri Lanka (1978).
- Tomei, Manuela. "A Plan for the Cultural Preservation and Development of the Veddhas" (1992), pp. 10-11.
- Tomei, p. 11.
- Tomei, p. 11-13.
- Master Plan, Maduru Oya National Park. Sri Lanka Ministry of State, Department of Wildlife Conservation, October 1985, revised June, 1987, p. 40.
- Immigration Officer (anonymous), Colombo: personal communication to W. Stegeborn, July 1985.
- "Veddhas Want to Return to their Homelands in the Jungle" Colombo: The Island, 14 May 1992.
- Dayaratna, P. "Establishment of a Sanctuary in 1500 acres of land within the Maduru Oya National Park for Uruwarige Tissahamy and the Veddha clan to pursue their traditional way of life". (note to Sri Lankan Cabinet) 19 June 1990.
- Map A: Traditional Vedda settlements in Sri Lanka
- Map B: Mahaweli Vedda resettlement areas
- Map C: Vedda hamlets in Maduru Oya National Park
Text and maps from report submitted to Sri Lanka's National Committee for the International Year of the World's Indigenous People in 1994 by Cultural Survival of Sri Lanka. For more information contact the author at: email@example.com.


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William's Magic
A visual masterpiece designed by Shin Lim and Tom Elderfield is used as a closer to Shin's Encore Act performed on the Illusionists Show from broadway. What more is there to say? Gone Deck can both be used as an APPEARING and VANISHING card box, making this a very versatile prop to anyones repertoire. Every package comes with a premade template so that you can apply any deck of your choosing and use it in the beginning, end, or even middle of your routine. And because it is simply one card thin and works as one unit with no separate parts to worry about, Gone Deck will not get in the way of your performances. Gone deck comes with an instructional tutorial on how to perform different vanishes, appearances, and even color changes. In addition, Shin Lim teaches you how to not only take care of your gimmick, but also how to create new ones of your own. Witness this incredible appearing and vanishing card box 5 years in the making "WTF!!! The Holy grail effect to open or close your card act!" - Rich Piccone *SansMinds and Nicholas Lawrence had independently created a similar effect called Unboxing.
This product was added to our catalog on Monday 08 February, 2016.


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- Availability:
- In Stock
- Product Code:
- CPat 193
Funny animal rattles noon One and Two Company today! With this set of designs, you can make a teddy bear, a giraffe, a frog and a pig in different versions. Add arms and wooden rings, or leave the rattle handles plain. Use bright colors to awaken your baby's curiosity or soft colors to relax your little one. Do you already know which is the perfect rattle for your baby?
This pattern includes:
· 5 languages: English, German, Dutch, Spanish and French.
· Skill Level: Easy / Intermediate
Measurements (height):
· Teddy Bear: 5 inches (12.5 cm).
· Giraffe: 5.5 inches (14 cm).
· Frog: 4.7 inches (12 cm).
· Pig: 5 inches (12.5 cm).
· I used Sport Yarn for this pattern.
· Written in American English crochet terms (English version).
· My patterns have Detailed Text instructions and symbol CHART instructions to help you.
You will need Adobe Reader to open this Pattern. The program can be downloaded for Free at http://www.adobe.com
By purchasing this pattern you agree to the following:
This pattern is copyright protected and cannot be sold, transmitted, distributed or reproduced in any form or by any means. However, you are welcome to donate, gift as well as sell any of your finished items (if you are an Individual Crafter). If you sell your work online, please link to my shop at http://www.oneandtwocompany.com
Flower vector created by freepik - www.freepik.com
Please, read the Policies of my Shop for more information.
If you have any question don't hesitate to contact me.
"Be Creative. Be Original"
© 2020 One and Two Company


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Professional Development Offerings >> Organization Development
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Organization Development Approaches and Consulting
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Old Glory Cuff Beanie
Made for the outdoors, the Old Glory Cuff Beanie doesn't skimp on warmth.
Our house-spun acrylic blend and 3M Thinsulate™ Insulation help you withstand the most frigid environments out there with unparalleled comfort, classic style, and functionality. Whether it's an arctic blast in the Midwest or you're braving the elements in the Rockies, we've got you covered.
Care Instructions: Wash with like colors, lay flat to dry.
- Yarn spun in-house
- Lined with 3M Thinsulate™ Insulation
- Cuffed
- Embroidered logo
We offer free U.S. shipping on orders $100+, and our products ship from our Cleveland, Ohio factory. Please note that shipping times do not account for fulfillment time. Returns or exchanges are accepted within 30 days of order date, and exclude marked down items such as Seconds. For more information, check out our Shipping + Returns page.


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Images in Cocoa Touch, represented by the UIImage class, are a very important subject. Apple's iOS platform prides itself on visual appeal, with Retina Displays, custom UI in many top apps, and a focus on photos with apps like Instagram. To that end, it behooves you as an iOS programmer to know a bit about working with images. This post won't discuss everything you need to know about using the UIImage class, as that's more appropriate for a book than a blog post—though maybe a series of blog posts would do—but instead will focus on one advanced topic: working with pixel data. You can find the basic stuff in the UIImage documentation, anyway.
Turning an Image Into Data
One of the first things you might want to do with a UIImage object is to save it to disk. To do that, you'll need to save it to an image file. There are built-in functions to get properly-formatted data from an image, in both PNG and JPEG functions:
- UIImagePNGRepresentation(), which returns an NSData object formatted as a PNG image, taking a pointer to a UIImage object as its sole parameter.
- UIImageJPEGRepresentation(), which returns an NSData object formatted as a JPEG image. Like the previous function, its first parameter is a pointer to a UIImage object, but it has a second argument: a CGFloat value representing the compression quality to use, with 0.0 representing the lowest-quality, highest-compression JPEG image possible, and 1.0 representing the highest-quality, lowest-compression image possible.
Once you have the image data represented by an NSData object, you can then save it to disk with various NSData methods, such as -writeToFile:atomically:.
Getting Raw Pixel Data
While the above functions are great for saving images, they aren't so great for image analysis. Sometimes you need to analyze the pixel data for a given pixel, down to the values for the red, green, blue, and alpha components. To get that kind of granularity in an image, we'll be using a lot of CoreGraphics functions. If you haven't used CoreGraphics before, know before going in that it's a C-based API à la CoreFoundation, so you won't be using the Objective-C objects you know and are used to. Instead, there are opaque types (represented by CFTypeRef, which is analogous to Objective-C's id) representing objects grafted onto C, complete with manual memory management—no ARC for you. That's neither here nor their, however; let's talk about pixel data.
Color Space
The color space of an image defines what the color components of each pixel are. Represented by the CGColorSpace type, you'll typically use either an RGB color space or a Gray color space, which have red, green, and blue components or a white component, respectively. For this example, we'll be using the RGB color space. We can create an instance of it with the CGColorSpaceCreateDeviceRGB() function, which returns a CGColorSpaceRef type—think of it as a pointer to a CGColorSpace object.
What does using this color space get us? We now know that the pixels of our image will have three color components, and in what order. This will come in handy later on when we need to query the data.
Graphics Contexts
A graphics context, represented by the CGContext type, is analogous to a painter's canvas—it's what you draw into. For the purposes of drawing an image, you'll create a CGBitmapContext, the ideal type of context for this data. You create a context with the CGBitmapContextCreate() function, which return a CGContextRef type. Let's look at the declaration of that function (from CGBitmapContext.h):
CGContextRef CGBitmapContextCreate ( void *data, size_t width, size_t height, size_t bitsPerComponent, size_t bytesPerRow, CGColorSpaceRef colorspace, CGBitmapInfo bitmapInfo );
So, that's pretty simple, right? It's actually fairly straightforward, despite its appearance. Let's break it down into more easily-digestible components. It'll make more sense if we don't go top-to-bottom, so we'll go in the order I think makes the most sense.
First is the bitmapInfo parameter. The CGBitmapInfo type is a bitmask that represents two options: the alpha component, which contains transparency information, and the byte order of the data. We'll talk about the alpha component here; byte order is another topic altogether. On iOS, only some pixel formats are supported. Looking at this chart in the documentation, we can see that, for all supported pixel formats on iOS in the RGB color space, these are the CGBitmapInfo constants we can use:
- kCGImageAlphaNoneSkipFirst
- kCGImageAlphaNoneSkipLast
- kCGImageAlphaPremultipliedFirst
- kCGImageAlphaPremultipliedLast
We can do two things with the alpha component: skip it, or use it in a premultiplied format. The premultiplied flag tells the system to multiply the individual red, green, and blue components by the alpha value when storing it. So, instead of RGBA values of 1, 1, 1, and 0.5, it's stored as 0.5, 0.5, 0.5, and 0.5. This is a performance-saving measure on iOS devices, and is done automatically to all of your PNG images by Xcode when you build for a device.
So, for the bitmapInfo parameter, I generally pass kCGImageAlphaPremultipliedLast.
The penultimate parameter, colorspace, is a CGColorSpaceRef pointing to a color space you've created. This informs the context about the number of color components. Keep in mind that there's one extra component for the alpha information if you're not skipping it, so an RGB color space uses 4 components including alpha.
The width and height parameters are pretty simple: the number of pixels wide and high to make the context. Keep in mind that for Retina displays, you may need to double the values. You can use the scale property of the main UIScreen object as a quick "am I on a Retina device?" check.
Next, let's talk about the first parameter: data Here you have two options: to pass in a pointer to a region of memory you've allocated for the image data, or to pass NULL and have the graphics subsystem create it for you. If you're trying to access pixel data, however, it'll help to have a pointer to the data, so here you'd pass in memory you've allocated. How do you know how much is enough? Let's look at the bitsPerComponent parameter. I usually use 8-bit components—again, see the chart linked above for valid options—so I would pass 8 for bitsPerComponent. Once you know that, you can determine bytesPerRow easily:
size_t bytesPerRow = (bitsPerComponent * width) / 8;
And then, finally, we can determine how much data to use. I use the uint8_t data type to represent this, as it's an unsigned 8-bit integer, perfect for our needs.
uint8_t data = calloc((width * height) * numberOfComponents, sizeof(uint8_t));
The entire stack might look like this:
The only thing in this code that we haven't gone over so far is the call to CGContextDrawImage, which (surprisingly) draws the image. It takes three parameters: the context to draw into, a CGRect defining where to draw, and a CGImageRef for the image. You can obtain a CGImageRef from a UIImage using its -CGImage method.
Now that the image is drawn in our context, the rawData array will be filled with real, live image data! You can access it like so (modify the values of x and y as suits your needs):
int x = 0; int y = 0; int byteIndex = (bytesPerRow * y) + (x * bytesPerPixel); uint8_ t red = rawData[byteIndex]; uint8_ t green = rawData[byteIndex + 1]; uint8_ t blue = rawData[byteIndex + 2]; uint8_ t alpha = rawData[byteIndex + 3];
And there you have it! Now that you've gotten the data out of your image, do whatever you want with it. Just remember the blog authors you read along the way when Facebook buys you for a billion dollars.
Note: The venerable Mike Ash published a similar article while this one was half-done in my drafts folder. I thought about scrapping it altogether, but since mine is iOS-specific, and with some prodding from a co-worker, I decided to press on. Go read Mike's blog, too. It's awesome.


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Infection Prevention and Control is the work an organisation does to identify potential risks for spread of infection between patients (and between patients and staff) and to take measures to reduce that risk. The Practice takes its responsibility to do this very seriously.
All staff take responsibility for their own role in this and all staff receive regular training in their role in Infection Prevention and Control.


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We have included a preset configuration option found in the Details tab of the template settings. This option allows you to quickly and easily import and export all of your template settings. The option exports a JSON file which can be easily imported in to other template style.
We have also included the option to load any of the Example Styles demonstrated on the template demo. Simply select the Example Styles of your choice and click Load Preset. Note that any previous template settings will be overwritten.


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The 1.4L MultiAir Fiat Turbo Internal Wastegate Actuator (IWG) provides better turbo response and greater sensitivity when managing boost pressures. Designed as a direct bolt-on replacement for the factory parts, the Fiat Turbo Internal Wastegate Actuator is easy to install and requires no special tools or fabrication. It can't get any easier!
It is the responsibility of Turbosmart to warn its customers and employees that some products sold on this website contain chemicals known to the State of California to cause cancer, birth defects or other reproductive harm.
This product does not have a CARB EO #; it is not legal for sale or use in CA on pollution controlled motor vehicles. This is intended as a "Race Only" product to be used solely for competition. It's use is limited to closed-course and open-course racing that is formally sanctioned by a recognized racing organization; any other use including recreational off-road use, may be a violation of local, state and federal laws. It is the buyer's responsibility to verify legal use of this product for the intended application and use.