• 한국산학기술학회논문지
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• 제10권2호
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• pp.215-221
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• 2009

최근 원격검침에 대한 많은 방식의 연구 및 개발이 진행되고 있지만, 검침 값의 신뢰성, 전원공급 등 여러가지 문제점이 나타나고 있다. 이러한 문제점들을 포토커플러를 이용한 디지털 펄스 계량기와 RF 모듈을 이용하였다. 본 연구에서 구현한 포토커플러와 RF, CDMA 통신을 활용한 원격검침 시스템은 기존의 시스템의 전 과정을 무인자동화 할 수 있고, 구역별 사용량 데이터 관리로 누수 상태의 실시간 확인이 가능하다. 그리고 사용자가 직접 확인이 가능하여 민원발생을 최소화할 수 있을 것이다. 더 나아가 지속적으로 증가하는 고령 인구들에 대한 실버산업의 일환으로 독거노인들의 안전관리시스템으로도 도입할 수 있을 것이다.

• Design & Manufacturing
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• 제16권1호
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• pp.55-61
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• 2022

As meters become digital and smart, energy data such as electricity, gas, heat, and water can be accurately and efficiently measured with a smart meter, providing consumers with data on energy used, so that real-time demand response and energy management services can be utilized. Although it is developing from a simple metering system to a smart metering industry to create a high value-added industry fused with ICT, illegal counterfeiting of electronic meters is causing problems in intelligent crimes such as manipulation and hacking of SW. The meter not only allows forgery of the meter data through arbitrary manipulation of the SW, but also leaves a fatal error in the metering performance, so that the OIML requires the validation of the SW from the authorized institution. In order to solve this problem, a quantitative confirmation device was developed in order to eradicate the act of cheating the fuel oil quantity through encoder pulse operation and program modulation, etc. In order to prevent the act of deceiving the lubricator, a device capable of checking pulse forgery was developed, manufactured, and verified. In addition, the performance of the device was verified by conducting an experiment on the meter being used in the actual field. It is judged that the developed quantitative confirmation device can be applied to other flow meters other than lubricators, and in this case, accurate measurement can be induced.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.377-379
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• 2007

To reduce the chattering errors of reed switch sensors used for automatic remote measurement of water supply system, a reed switch sensor was analyzed and improved. The operation of reed switch sensors can be described as a mechanical contact by approximation of permanent magnet piece to generate an electrical pulse. The reed switch sensors are used in measurement application by detecting the rotational or translational displacement. To apply for flow measurement devices, the reed switch sensors should keep high reliability. They are applied for the electronic digital type of water flow meters. The reed switch sensor is just installed simply on the mechanical type flow meter. A small magnet is attached on a pointer of the water meter counter rotor. Inside the reed sensor, two steel leaf springs make mechanical contact and apart as rotation of flow meter counter. The counting electrical contact pulses can be converted as the water flow amount. The MCU sends the digital flow rate data to the server using the wireless communication network. But it occurs data difference or errors by chattering noise. The reed switch sensor contains chattering error by it self at the force equivalent position. The vibrations such as passing car near to the switch sensor installed location. In order to reduce chattering error, most system uses just software methods for example using filter and also statistical calibration methods. The chattering errors were reduced by changing leaf spring structure using mechanical hysteresis characteristics.

• 전자공학회논문지SC
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• 제44권4호통권316호
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• pp.42-47
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• 2007

상수도 원격 검침에서는 리드 스위치의 채터링 오차를 감소시키기 위한 센서 연구 및 개선이 필요하다. 센서의 동작은 전기적 펄스를 발생시키기 위한 영구 자석 주각의 접근에 의한 기계적 접촉스위치처럼 나타낼 수 있다. 대부분 회전 또는 전달 이동을 잡기 위해 사용되고 수류 측정 장치에 적용하기 위해서는 높은 신뢰성이 필수이다. 동작 형태를 간단히 설명하게 되면 미터기 작동 모터 끝에 달려있는 작은 자석이 미터기 회전에 의해 리드 스위치 내부에 있는 두 개의 스프링과 기계적 접촉 형식으로 반복적으로 떨어지게 된다. 즉 수류량에 따라 펄스의 수가 증가하는 것이다. 이렇게 측정된 값은 무선 이동 통신을 통해 서버로 전달되게 된다. 문제는 자석과 리드 스위치가 만나는 지점에서 스위치가 멈추게 되면 떨리면서 펄스가 잘못 올라가는 오차가 생기는 것이다. 이러한 오차를 감소시키기 위해 보통 소프트웨어적인 방법을 사용한다. 필터 알고리듬을 사용하는것과 통계적인 보정방법을 사용하는 것이 그러한 예이다. 하지만 그러한 방법보다는 하드웨어적으로 문제를 해결하는 것이 오차를 줄일 수 있는 더 직접적인 방법이다. 본 논문에서는 기계적인 이력현상의 특성을 이용하여 리프 스프링 구조의 변화로 오차를 감소시키는 연구를 수행하였다.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2001년도 전지기술심포지움
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• pp.145-161
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• 2001

Novel characterization of thermal properties of a battery has been introduced by defining its frequency-dependent thermal impedance function. Thermal impedance function can be approximated as a thermal impedance spectrum by analyzing experimental temperature transient which is related to the thermal impedance function through Laplace transformation. In order to obtain temperature transient, a process has been devised to generate external heat pulse with heating wire and to measure the response of battery. This process is used to study several commercial Li-ion batteries of cylindrical type. The thermal impedance measurements have been performed using potentionstat/galvanostate controlled digital signal processor, which is more commonly available than flow-meter usually applied for thermal property measurements. Thermal impedance spectra obtained for batteries produced by different manufactures are found to differ considerably. Comparison of spectra at different states of charge indicates independence of thermal impedance on charging state of battery. It is shown that thermal impedance spectrum can be used to obtain simultaneously thermal capacity and thermal conductivity of battery by non-linear complex least-square fit of the spectrum to thermal impedance model. Obtained data is used to simulate a response of the battery to internal heating during discharge. It is found that temperature inside the battery is by one-third larger that on its surface. This observation has to be considered to prevent damage by overheating.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.548-551
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• 2007

Among components of digital topographic maps used officially in Korea, only contours have 3D values except buildings and trees that are demanded in landscape planning. This study presented a series of processes for 3Dreconstructing landscape features such as terrain, buildings and standing trees using LiDAR (Light Detection And Ranging) data and aerial digital photo graphs. The 3D reconstructing processes contain 1) building terrain model, 2) delineating outline of landscape features, 3) extracting height values, and 4) shaping and coloring landscape features using aerial photograph and 3-D virtual data base. LiDAR data and aerial photograph was taken in November 2006 for $50km^{2}$ area in Sorak National Park located in eastern part of Korea. The average scanning density of LiDAR pulse was 1.32 points per square meter, and the aerial photograph with RGB bands has $0.35m{\times}0.35m$ spatial resolution. Using reconstructed 3D landscape features, visibility with the growing trees with time and at different viewpoints was analyzed. Visible area from viewpoint could be effectively estimated considering 3D information of landscape features. This process could be applied for landscape planning like building scale with the consideration of surrounding landscape features.

• 대한물리치료과학회지
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• 제6권4호
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• pp.173-178
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• 1999

The purpose of this study was to determine the effect of High Voltage Pulsed Current on pH in the healing wound bed. Seven adults, four males and three females, were studied with a total of fifty-five viable treatment sessions. Using a Cardy Digital pH meter, we measured the pH in the wound bed following saline rinse both prior to treatment and after a forty-five minute treatment. Analysis of all viable records(n=54) did not show a significant change in pH(p=0.82). The mean pH change in NoN-Smokers(-0.14) was more acidic when compared to the mean pH change in smokers(0.27) which was more alkaline.