This invention relates to a system and method for establishing a secure group of entities in a computer network, such as those originating from different trust domains, for the purpose of protecting the activity being executed. The loader excavator comprises a main boom and a dipper boom, wherein a loader bucket or an excavator bucket can be selectively utilized in accordance with user preference. The single frame comprises an event type identifier that is operable to identify the single frame as corresponding to the one-frame event. The negative electrode is wound at least one extra turn from the winding end of the positive electrode of the capacitor element, and hence a part where the polarized electrode layers formed in the negative electrode face each other through the separator is formed on the outermost periphery of the capacitor element. A wire brush makes contact with a rotating surface of the generator to carry away electricity, and the wire brush is continuously fed to make up for wear.