Corrosion engineering is the field dedicated to controlling and preventing corrosion. Corticosteroids are effective in controlling and suppressing symptoms in most cases. CM emphasizes the functional relation between parts, subsystems, and systems for effectively controlling system change. Local authorities are considering means of controlling or eradicating it. It is responsible for controlling circadian rhythms. Spacecraft are vehicles capable of controlling their trajectory through space. Aircraft have means of automatically controlling flight. Their challenges are controlling disease and producing sufficient food. Some are purely ornamental, while others are useful in controlling algae and removing debris. They focus on controlling and directing regular employees. Testosterone is one of the hormones controlling libido in human beings. This helps them gain experience in controlling females. Managers undertake the tasks of planning, budgeting, organizing, staffing, controlling and problem solving. One purpose of region coding is controlling release dates. The key to controlling decay is controlling moisture.