• 한국전기전자재료학회논문지
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• 제20권3호
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• pp.218-222
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• 2007

In this study, Acoustic emission(AE) sensors were fabricated using lead-free piezoelectric ceramics for prohibiting environmental pollution. Structure of AE sensors were designed as Langvin type air backing form. Here, the piezoelectic element was used as PZT(EC-65)(AE1) and NKN(AE2), respectively. The measured resonant frequency, the maximum sensitivity frequency and sensitivity of AE sensors were as follows ; 143 kHz, 29.4 kHz and 69.3 dB in AE1 and 179 kHz, 29.4 kHz and 66.3dB in AE2, respectively.

• 자동차안전학회지
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• 제11권1호
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• pp.48-54
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• 2019

Optimal engine control is needed to cope with the global environmental regulations that are globally enforced. For optimum engine control, the electronic throttle control system (ETCS) is a prerequisite. Automotive makers are having an effect on reducing emissions and improving fuel economy by applying ETCS which is designed to secure stability. The ETCS controls the output of the throttle valve by passing the output value of the accelerator position sensor (APS) to the engine control unit (ECU). In this study, the authors investigated the safety standards of domestic and overseas accelerator control system and tried to understand how the air flow control affects the engine output by replacing the throttle. The authors suggest an improvement proposal of safety standard based on the result of driving evaluation by various modes.

• 센서학회지
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• 제32권4호
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• pp.213-218
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• 2023

Triboelectric nanogenerators (TENGs) have emerged as a highly promising energy harvesting technology capable of harnessing mechanical energy from various environmental vibrations. Their versatility in material selection and efficient conversion of mechanical energy into electric energy make them particularly attractive. TENGs can serve as a valuable technology for self-powered sensor operation in preparation for the IoT era. Additionally, they demonstrate potential for diverse applications, including energy sources for implanted medical devices (IMDs), neural therapy, and wound healing. In this review, we summarize the potential use of this universally applicable triboelectric energy harvesting technology in the disinfection and blocking of pathogens. By integrating triboelectric energy harvesting technology into human clothing, masks, and other accessories, we propose the possibility of blocking pathogens, along with technologies for removing airborne or waterborne infectious agents. Through this, we suggest that triboelectric energy harvesting technology could be an efficient alternative to existing pathogen removal technologies in the future.

• 한국환경보건학회지
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• 제48권1호
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• pp.44-51
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• 2022

Background: Air pollution is increasing together with industrialization and urbanization. In order to reduce air pollution, public transportation is recommended rather than private cars, and the number of passengers using public transportation is increasing accordingly. This study observes the concentration of indoor pollutants in city buses over time. Through this means, we intend to suggest a plan to manage the indoor air quality in city buses. Objectives: The concentration of indoor pollution in public transportation was investigated from April 2021 to January 2022. Based on this, we evaluated the exposure to indoor pollutants. Methods: Six city bus lines in an industrial city were selected for the research, and indoor pollution was measured through IoT (Internet of Things)-based sensor-type measuring devices. The concentration of pollutants was measured every minute, and statistical data were constructed based on the measurement results. Results: In all the city buses studied, the average concentration of pollutants were below the guidelines. However, some measurement results showed cases of exceeding the guidelines. As a result of the analysis by time zone, there were more cases in which pollutants exceeded the standard value during rush hour compared to at other times. A risk assessment for PM₁₀ was performed by evaluating the excess mortality risk from exposure and the risk from inhalation exposure. Conclusions: All measured indoor pollutants in the city buses did not exceed the guidelines. Also, the risk assessment results were found to be within the level of safety. However, if a city bus is used for a long time, there is a possibility that there may be an impact on the human body due to inhalation exposure, so additional management is required.

• 한국정보통신학회논문지
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• 제14권6호
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• pp.1488-1492
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• 2010

유비쿼터스 센서 네트워크는 부착된 태그와 센서로부터 사물 및 환경 정보를 감지, 저장, 가공, 전달하여 인간 생활에 폭넓게 활용되며, 환경오염에 대해서도 사람이 직접 측정 및 모니터링 하기 힘든 지역에 설치되어 활용되고 있다. 기존 네트워크에 비해 초소형, 저전력, 저비용으로 쉽게 구성 가능하기 때문에 꾸준히 연구되어지고 있으며 환경과 IT의 전략적 융합을 통한 그린 IT의 네트워크 접목 또한 중요한 연구 분야로 조명되고 있다. 본 논문에서는 네트워크 기반하에 실내 공기질 관리 센싱 메커니즘 구성도를 구현하고 환경요소를 측정하여 향후 환경 모니터링 시스템의 활용방안을 제안한다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.467-470
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• 2010

유비쿼터스 센서 네트워크는 부착된 태그와 센서로부터 사물 및 환경 정보를 감지, 저장, 가공, 전달하여 인간 생활에 폭넓게 활용되며, 환경오염에 대해서도 사람이 직접 측정 및 모니터링 하기 힘든 지역에 설치되어 활용되고 있다. 기존 네트워크에 비해 초소형, 저전력, 저비용으로 쉽게 구성 가능하기 때문에 꾸준히 연구되어지고 있으며 환경과 IT의 전략적 융합을 통한 그린 IT의 네트워크 접목 또한 중요한 연구분야로 조명되고 있다. 본 논문에서는 네트워크 기반하에 실내 공기질 관리 센싱 메커니즘 구성도를 구현하고 환경요소를 측정하여 향후 환경 모니터링 시스템의 활용방안을 제안한다.

• 한국입자에어로졸학회지
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• 제18권3호
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• pp.61-68
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• 2022

In this study, a fluidized bed particle generator was developed to generate an aerosol without supply of compressed air and to increase portability. It was assumed that the mixing ratio of the test particles and beads, the input amount, and the air flow rate supplied to the generator would have effect on the aerosol generation characteristics. The product of these three parameters was set as a characteristic parameter and particle generation characteristics according to the change of the characteristic parameter were observed. As a result, it was confirmed that the input amount of test particles and beads was not suitable as a characteristic parameter and a characteristic parameter expressed as a product of the mass mixing ratio and the air flowrate was newly defined. When the new characteristic parameter is applied, it can be confirmed that the total amount of particles generated from the particle generator is a function of the characteristic parameter. As a result of measuring the amount of particle generation by adjusting the characteristic parameter, it was confirmed that the performance required for the test particle generator for the field inspection equipment of PM-2.5 sensors could be satisfied.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.997-1000
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• 2006

We estimate the net heat flux in the tropical and subtropical Atlantic Ocean using satellite data. These fluxes are related to changes in sea surface temperature (SST). This variable influences atmospheric circulations and is indicative of surface and subsurface oceanic circulations. We employ data from the geostationary METEOSAT-7 and 8 satellites and from the Special Sensor Microwave/Imager (SSM/I) for the shortwave and long-wave radiative fluxes, and for estimates of SST. For turbulent flux calculations, we use the bulk aerodynamic method with satellite estimates for wind speed and atmospheric humidity and temperature.

• 한국환경과학회지
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• 제9권5호
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• pp.385-388
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• 2000

Visibility reduction is a barometer of air pollution which people can notice easily. First of all we need to measure quantified visibility continuously in order to examine visibility reduction. Prevailing visibility is not practical to measure visibility depending on observer's expertness. Scattering visibility using Forward Scattering Meter(Belfort Visibility Sensor 6230) has been measured at Kwangan-Dong in Pusan and analysed since July 1998. According to the analysis the correlation coefficient(R) between prevailing visibility and scattering visibility was 0.7235. The visibility appeared that each frequency of poor visibility(under 6km) and good visibility(over 25km) was 10.6%, 9.7% on summertime in Pusan and the visibility range from 10km to 20km ranked high frequency as a half of whole ranges. The order of correlation coefficients between visibility an air pollutants are ranking CO. PM10 and NO2 that values are 0.5878, 0.5369,l 0.5284 respectively. In meteorolgical factor the case of poor visibility presented more weakly wind speed and higher relative humidity than the case of good visibility. The correlation coefficient between calculated visibility of multiple linear regression model and observed visibility was 0.7215. But the trend of calculated and observed visibility variation was similar with the exception of several good visibility cases.

• 전자공학회논문지 IE
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• 제45권3호
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• pp.27-35
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• 2008

본 논문은 다중 가스 필터 휠 (multi gas filter correlation wheel: multi GFC wheel)을 갖는 비분산 적외선법(NDIR method : non-dispersive infrared method)을 이용하여 대기 중 다종환경오염물질(CO, $SO_2$, NOx 등)을 동시에 실시간 측정할 수 있는 광학분석장치 개발을 위한 미세신호 검출 알고리즘을 제안한다. MCT(mercury cadmium telluride) 센서를 통해 측정된 각각의 환경오염물질의 미세신호는 고유한 NDIR 흡수 특성을 갖는다. 제안한 방법은 임계값과 하나의 외부 동기신호를 사용하여 연속적으로 측정된 신호로부터 각각의 오염물질 특정농도에 해당하는 데이터를 분리 검출한다.