The environmental monitoring technology has changed from passive logging system to intelligent networked sensor system. The sensor node measures the physical, chemical and biochemical quantities, and transfers the data to the base station by wireless sensor network. The sensor network server integrates these data as the environment datasets, and uploads to a cloud server. The technology facilitates the development of hazard detection and alert system. The examples in the natural world, agriculture and industry are reviewed in this paper. The environmental monitoring network is divided into four different categories in the scale and function. The environmental monitoring will become a standard and fundamental tool in the future society.

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An emitter current sensor was proposed in order to measure ion generation rates of corona discharge air ionizers aiming to investigate the effects of the operating condition on the neutralization performance. The emitter current is one of the most important operating conditions of a corona discharge air ionizer. A current sensor with high sensitivity is needed because the emitter current is small (nA or pA) and the voltage applied to the emitter is high (kilo volts). So, it is desirable to separate electrically the current detector from high voltage line. The proposed sensor consists of two areas: the high voltage region for detecting the emitter current, and the low voltage region for measuring the wave forms of the emitter current by using oscilloscope. The ion generation rates were obtained from the waveform of the difference between the total current and the displacement current. A MOSFET was used for detecting the emitter current, which enables to realize low cost measurement.

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Low power consumption and high temperature operation are important in an environmental monitoring system. The power consumption of 3mW is achieved for the radiation sensor using low voltage operational amplifier and comparator in the signal processing circuit. The leakage reverse current of photodiode causes the charge amplifier saturation over 50°C. High temperature durability was improved by optimizing the circuit configuration and the values of feedback resistance and capacitance in the charge amplifier. The pulse response of the radiation sensor was measured up to 55°C. The custom detection circuit was designed by 0.6µm CMOS process at 5V supply voltage. The operation temperature was improved up to 65°C.

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This Paper has been decided to be retracted, as per proposal from the author.

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Life monitoring systems with air pollution data have been developed for solitary elderly people. However, the existing systems obtain unnecessary information that invades their privacy. In addition, since degrees of air pollution change in distinctive ways due to the effect of home environment and airflow condition, it is difficult for people who have no expert knowledge to identify activities of their daily living (ADL). To solve the problems above, this paper presents a system to select useful information that is required to identify ADL. Experimental results have shown that the proposed system achieves 77.3% identification accuracy. Besides, compared with the case when 10 users were asked to identify ADL without the proposed system, the identification accuracy has increased by 11.3% with the proposed system.

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A method for fabricating multilevel interconnection structures using differential delamination energies (adhesion strength) between metal and silicon oxide thin films has been developed. When the selectivity of the delamination energies between the metal and the silicon oxide thin films sets on the wiring, the silicon oxide thin film can be released on the low delaminaion energy area and can be held on the high delamination energy area by using ultrasonic waves. The delamination energies are calculated by using a molecular dynamics simulation. The delamination energies between chromium, titanium, and nickel and silicon oxide thin films are larger than those of copper and gold thin films. The chromium, titanium, and nickel are applied as an adhesion layer with silicon oxide, and the copper and gold are applied as a release layer from silicon oxide. The results are applied to the process for fabricating the multilevel interconnection structures, and the release and the adhesive areas of silicon oxide thin film can be fabricated on the wiring by adding ultrasonic waves. With this method, the lower wrings and the contact areas of the multilevel interconnection structures can be easily fabricated.

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