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Because of low temperatures and oxygen in cold water, fish will die when cold currents arrive. This will cause tremendous loss of money. In order reduce the cooling of the pond, an automatic thermal detecting and cold-roofing system using a wind-proofing device, heaters, and thermal detectors is proposed. To reduce heat loss due to thermal convection above the pond surface, a motor-driven wind-proofing device automatically controlled by a PLC controller is adopted. Here, the wind-proofing device, thermal detectors, and heating system are connected to the PLC controller. The PLC will also be connected to the PC interface. The temperature thresholds used to trigger the heater and the wind proofing device can be set at the PC interface. Two options for manipulating the heating and the automatic heating can be selected. The related wind-proofing area and the number of heaters will be determined according to the current temperature. Moreover, the PLC can be wirelessly connected to the server PC in the control room. The pond keeper can monitor everything online and control the pond water's temperature. With this, the problem of fish dying in a cold wave can be solved. Consequently, to reduce the electrical exhaust when heating up the pond water, green energy, solar energy and wind energy, is used.

The traditional structure of dual mode bandpass filter is formed by a circular or rectangular resonator, which causes excessive circuit areas to be occupied. A 5.2 GHz bandpass filter, based on the triple-branch self-coupled ring resonator, is designed to achieve most essential features such as low insertion loss, compact size, and wide stopband. The coupling of each coupled branch introduces the even- and odd-mode perturbation, which produce sharp bandpass and wide stopband responses due to the generation of band-edge transmission zeros. The simulation and measurement in this paper are respectively verified by using IE3D electromagnetic simulator and Agilent's HP8722C network analyzer. Experimental results show that the filter has 19.2% bandwidth centered at 5.2 GHz, 1.2 dB insertion loss, 25 dB stopband rejection from 6 to 9 GHz. Moreover, the circuit size in this paper has been down to 9×6 mm2 and can be applied to communication of microwave applications.

A 915 MHz printed radio-frequency-identification (RFID) antennas with the characteristics of good gain and omnidirectional beam wave is constructed and evaluated in this study. The objective is to find out their best reading rates for providing effective wireless communications among RFID antenna during the library book inventory process. And an optimal library inventory system which is based on electromagnetic identification (EMID) technology is proposed, which is constructed to find the optimal tag location for a book, test the tag readability for bookshelves, and connect a couple of multi-layer bookshelves with multiplexers and updat the tag reading status in the database of the computer terminal. The fabricated antenna reader and the proposed system are embedded into different locations of bookshelves and tested at the library of Cheng Shiu University in Taiwan. According to the experimental results, the designed prototype of the antenna reader has the characteristics of the directional radiation pattern, good gain, simple shape, low cost and is easy to be integrated into the bookshelf. And the designed library inventory system can authenticate the location of a book automatically. They can benefit administrating librarians with the capabilities of decreasing the library inventory processing time and reducing the possibility of the books being misplaced.