• Journal of the Korean Geosynthetics Society
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• v.21 no.3
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• pp.71-78
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• 2022

In this study, the applicability of underground displacement sensors was considered through rock blasting tests to develop a relatively inexpensive and efficient slope failure prediction system that can quickly detect the risk of slope failure in advance and issue predictions and warnings with accurate judgment. In the blasting experiment, the sensor located close to the blasting source showed a large displacement due to crushing inside the rock and the sensor located away from the blasting source showed a relatively small strain. This study confirmed that the wired and wireless type underground displacement sensor system can be applied to measure the behavior of the rock slope, and it can be used as a basic data for establishing an early warning system to predict slope failure.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.129-135
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• 2002

The present article deals with the measurement and the numerical calculations far the temperature distribution near the facing of the lockup clutch. The rotating telemetry system is Introduced for the estimation inside high-speed torque converter For the numerical calculation, the effect of the convective heat transfer is considered as well as the conduction to the solid. The estimation shows that the oil temperature near facing rapidly rises as the lockup clutch is engaged. The numerical results shows good agreements with the experimental values for the maximum temperature near the facing of the lockup clutch.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.3 s.258
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• pp.242-247
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• 2007

Energy savings and environmental protection policies have been the general trend in the engine design. The friction power loss associated with the cam mechanism has become important. But it is difficult to measure the torque of rotating valvetrain in real engine environment because most of conventional torque meters are axial type. The objective of this paper is to develop new equipment which can be installed in a rotating camshaft. It uses strain gages to measure the elastic deformation of torque sensor which replaces the cam sprocket. It includes telemetry to transmit torque data via Bluetooth and induction power system to provide adequate power to rotating torque meter. The developed torque meter has good linearity and thermostability. It was installed in a real engine, and successfully measured the valvetrain torque.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.273-275
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• 2009

In recent years, many home machines have been developed in order to design and control comfortable interior inside houses. For such task, important factors are temperature, natural and interior lights, and space and control of relative factors each other. This paper presents novel sensor module inside houses, which is designed based on these factors through the PMV (Predicted Mean Vote) standard using information about home state. Moreover, LonWorks based power line communication technique is utilized for control interior lights and air-conditioners by means of wireless remote controllers. This mechanism is systemically operated via intelligent control framework.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.678-681
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• 2007

In this study, an implementation of a system for measuring more accurate blood pressure by non-invasive methods of oscillometric was performed. The system were composed of pressure control, signal measurement, blood pressure signal processing units and wireless sensor network parts. For verify the validity of the system, tests of characteristics evaluations for pressure measurement unit, extraction of characteristic ratios for blood pressure estimation, blood pressure tracking by oscillometric method were performed. A group of five adult male was selected for the clinical test of the implemented system. The results of the oscillometric method in comparison with auscultatory method are that the maximum ratios of PAD of average, systolic and diastolic arterial pressure are 1.38%, 1.63% and 2.97% with SEP of 5.00, 3.72 and 4.34.

• Smart Media Journal
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• v.12 no.5
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• pp.81-87
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• 2023

In this paper, accidents in high-voltage overhead distribution lines, which provide stable power supply in the power system, cause inconvenience in life and disruption of production of companies. 22.9 [kV] high-voltage overhead power distribution lines aim to improve reliability and stability, such as damage caused by rain, snow, wind, etc., or electric shock prevention. Therefore, in order to prevent wire disconnection accidents due to deterioration of electrical conductivity or tensile strength due to corrosion of overhead distribution lines, it is necessary to prevent unexpected accidents in the future through regular inspection and repair. In order to diagnose deterioration due to corrosion of distribution lines, a diagnostic system (measuring instrument) is installed on the wires to monitor the condition of the wires. The manager on the ground receives the measured data through ZigBee wireless communication, controls the diagnosis system through the diagnosis system program, and grasps the condition of the overhead distribution line through the measured data and photographed photos, and predicts the life of the wire along with the visual inspection method. developed a program.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.5
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• pp.315-321
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• 2009

Remote water meter monitoring is essential in U-city applications, whoγe digital water meter is a key component. While there are several kinds of water meters, the way to use has sensors has the merit of better preciseness, but the drawback of more power consumption. In this paper, we suggest an advanced sensing algorithm to diminish the power consumption while keeping the quality of preciseness. Our approach is to use less precise hall sensor for detecting the start of water impeller rotation with lower power consumption. During the rotation, a high precision hall sensor is used to meter the amount of water consumption. Our algorithm is analyzed to get 2 times lower power consumption than the previous algorithm.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.1
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• pp.55-60
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• 2011

The mobile internet telephony service rapidly grows according to the extending deployment of smartphones. Unlike telephony service over a conventional public switched telephone network (PSTN) or mobile network, internet telephony service cannot guarantee its service quality, which can be severer in a wireless environment. Therefore, a more strict and systematic quality management is required for successful settlement and popularization of mobile internet telephony service. Existing quality management scheme using a specific measurement equipment cannot measure all the time so that it performs late management. In order to overcome the problem, this paper develops a software that can be equipped on a user terminal and measures the service quality all the time. By using the developed software, all-time and user-activating service quality monitoring can be supported.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.229-233
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• 2011

IT기술의 발달과 함께 최근 유비쿼터스 패러다임이 등장함에 따라 수자원분야의 정보화 환경이 변화하여야 한다는 논의가 활발하다. 빈번하게 발생하고 있는 자연재해에 있어서 주요 치수시설물의 안전모니터링은 새로운 기술의 적극적인 도입과 개발이 필수적이다. 또한 지속적인 수자원 관리 및 활용 고도화를 위해서도 정보화 경쟁력을 제고하고, 높아지는 사용자의 서비스 요구수준을 충족시켜야할 필요가 있다. 본 연구는 제방 및 보(수문)의 안전모니터링 선진화를 위해 다음과 같은 과정으로 연구하였다. 주요 치수시설물의 안전모니터링 요소를 분석하기 위해 붕괴원인 유형에 따른 주요 모니터링 취약성 인자를 도출한다. 취약성 인자 중 제방의 경우 침투, 침식, 월류, 구조물에 의한 붕괴 등에 의한 유형과 보(수문)의 경우 전도, 활동, 부유 등 다양한 관련 붕괴 현상을 검토하여 각각의 발생된 인자 특성별 모니터링이 가능하도록 최적 센서를 도출한다. 이러한 일련의 과정은 과거의 계측기를 통하거나 육안 및 수동적인 모니터링에서 벗어나, IT기술의 통신분야와 융합한 무선센서네트워크를 적용하여 경제성, 효율성, 현실성을 가지는 치수시설물의 모니터링이 가능하도록 하였다. 향후 이러한 USN(Ubiquitous Sensor Network) 등 유비쿼터스의 융합과 IT기술을 활용한 치수시설물 안전모니터링 선진화를 통해 홍수방어 및 관리시스템 구축에 활용되어 인명 및 재산피해를 절감하고 기술수준을 향상시킴으로서 홍수 재해로부터 안전한 국토 건설 및 국민의 삶의 질을 향상시킬 것이다. 또한, 국가 홍수관리 시스템 구축, 치수능력증대, 장래유역단위 통합홍수방어 및 관리기술 개발에 기여할 것으로 판단된다.

• Korean Chemical Engineering Research
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• v.60 no.1
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• pp.86-92
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• 2022

Recently, the bio-healthcare market is enlarging worldwide due to various reasons such as the COVID-19 pandemic. Among them, biometric measurement and analysis technology are expected to bring about future technological innovation and socio-economic ripple effect. Existing systems require a large-capacity battery to drive signal processing, wireless transmission part, and an operating system in the process. However, due to the limitation of the battery capacity, it causes a spatio-temporal limitation on the use of the device. This limitation can act as a cause for the disconnection of data required for the user's health care monitoring, so it is one of the major obstacles of the health care device. In this study, we report the concept of a standalone healthcare monitoring module, which is based on both triboelectric effects and electromagnetic effects, by converting biomechanical energy into suitable electric energy. The proposed system can be operated independently without an external power source. In particular, the wireless foot pressure measurement monitoring system, which is rationally designed triboelectric sensor (TES), can recognize the user's walking habits through foot pressure measurement. By applying the triboelectric effects to the contact-separation behavior that occurs during walking, an effective foot pressure sensor was made, the performance of the sensor was verified through an electrical output signal according to the pressure, and its dynamic behavior is measured through a signal processing circuit using a capacitor. In addition, the biomechanical energy dissipated during walking is harvested as electrical energy by using the electromagnetic induction effect to be used as a power source for wireless transmission and signal processing. Therefore, the proposed system has a great potential to reduce the inconvenience of charging caused by limited battery capacity and to overcome the problem of data disconnection.