The invention generally relates a method of determining completion criteria for a coal bed methane reservoir having a plurality of coal seams. A second III-V compound layer is disposed on the first III-V compound layer and is different from the first III-V compound layer in composition. The packet stream may comprise standard data packets. The current transfer unit transfers the generated current. A protective plastic cap covers the bolt head and has protrusions sheared off when the cap is removed to provide a tamper indication. Since the similar cases are determined taking a peripheral distribution of a new case into consideration, suitable similar cases can be selected for reasoning even when the case distribution is not uniform.