• 조명전기설비학회논문지
• /
• 제29권4호
• /
• pp.47-53
• /
• 2015

The electrical safety and efficiency is the most important thing of the electric vehicle charging system. The prior system is contact charging system that is contacted directly by human. So, it has riskiness such as electric shock in the case of poor insulation or contact problems. To solve these safety issues and the convenience problems, a wireless power transmission system has been developed and is currently in trial operation. However, because high frequency is used in wireless power transmission system instead of commercial frequency, we need to apply protection measures concerning electric shock and equipment protection. Also, it should be accompanied by measuring efficiency for the effective operation of the wireless power transmission system. Therefore, we structured monitoring system in trial operation area of wireless power transmission system and applied decision algorithm for protection of human and equipment and economic operation of it.

• Structural Monitoring and Maintenance
• /
• 제7권3호
• /
• pp.261-281
• /
• 2020

Civil structures may experience progressive deterioration and damage under environmental and operational conditions over their service life. Finite element (FE) model updating method is one of the most important approaches for damage identification in structures due to its capabilities in structural health monitoring. Although various damage detection approaches have been investigated on structures, there are limited studies on large-sized space structures. Thus, this paper aims to investigate the applicability and efficiency of sensitivity-based FE model updating framework for damage identification in large space structures from a distinct point of view. This framework facilitates modeling and model updating in large and geometric complicated space structures. Considering sensitivity-based FE model updating and vibration measurements, the discrepancy between acceleration response data in real damaged structure and hypothetical damaged structure have been minimized through adjusting the updating parameters. The feasibility and efficiency of the above-mentioned approach for damage identification has finally been demonstrated with two numerical examples: a flat double layer grid and a double layer diamatic dome. According to the results, this method can detect, localize, and quantify damages in large-scaled space structures very accurately which is robust to noisy data. Also, requiring a remarkably small number of iterations to converge, typically less than four, demonstrates the computational efficiency of this method.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1996년도 하계학술대회 논문집 B
• /
• pp.916-918
• /
• 1996

We have an urgent matter that is lack of energy resource. So we have to accomplish the design of economical energy utility systems and to develop energy facilities with high efficiency. Cogeneration system is one of them. It has high efficiency and can solve unbalanced electricity and heat demand in Summer & Winter concurrently. Recently, to increase the efficiency and stability of the total system, it is applying automatic control and monitoring software to the hardware facilities in industrial control systems. Therefore, these systems has been researched and developed in the advanced countries. It also has been researched and developed in the domestic since '60. But the control and monitoring software in cogeneration system has been hardly developed and has been imported expensive products from the advanced countries. In this study, we have developed the software of operating control, status monitoring, operating data managing and tele-controlling. We have confirmed usefullness of developed software by applying to gas turbine cogeneration system.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2008년도 춘계학술대회논문집
• /
• pp.821-825
• /
• 2008

Requirements of wireless sensor are increasing in machine condition monitoring. But, the limitation of battery power, self-power wireless sensor is necessary for the purpose of stand-alone operation. To overcome this problem, energy harvester is developed by the vibration energy. The purpose of this study is to develop a high efficiency energy harvester with high precision tuning.

• 한국수자원학회논문집
• /
• 제52권spc2호
• /
• pp.855-863
• /
• 2019

어류의 어도 이용효율평가를 위해서는 유인효율과 통과효율로 분리하여 분석할 때, 각각의 효율을 증대시킬 수 있는 방향으로 어도 설치 및 관리 계획이 수립될 수 있다. 기 설치된 어도는 어류 모니터링을 통해 보다 직접적으로 각각의 효율을 평가할 수 있다. 반면 어도를 계획할 때, 또는 여건상 어류 모니터링이 어려운 경우, 수리해석을 통해 간접적으로 어도 효율을 평가할 수 있다. 본 연구에서는 어도의 효율평가가 가능한 수리해석 기법을 제시하였다. 유인효율 분석에는 어류 물리서식처 모듈이 장착된 River-2D모형을 사용하였고, 효율의 지표로 가중가용면적을 제안하였다. 통과효율 분석에는 자유 수면을 가지고 수리구조물상의 유체거동을 해석할 수 있는 3차원 모형(Flow-3D)을 해석 도구로 이용하였다. 그리고 덕천강 백곡보에 설치된 아이스하버 어도를 선택하여 어도 효율을 가늠해 보았고, 실제 어류 모니터링자료와 비교해 보았다. 그 결과 수리해석 자료를 정량적으로 어도 효율로 치환하기는 어렵지만, 대체적인 경향성 파악에는 도움을 줄 수 있었다.

• Smart Structures and Systems
• /
• 제3권1호
• /
• pp.1-22
• /
• 2007

The energy efficiency of a self-powered wireless sensing system for pressure monitoring in injection molding is analyzed using Bond graph models. The sensing system, located within the mold cavity, consists of an energy converter, an energy modulator, and a ultrasonic signal transmitter. Pressure variation in the mold cavity is extracted by the energy converter and transmitted through the mold steel to a signal receiver located outside of the mold, in the form of ultrasound pulse trains. Through Bond graph models, the energy efficiency of the sensing system is characterized as a function of the configuration of a piezoceramic stack within the energy converter, the pulsing cycle of the energy modulator, and the thicknesses of the various layers that make up the ultrasonic signal transmitter. The obtained energy models are subsequently utilized to identify the minimum level of signal intensity required to ensure successful detection of the ultrasound pulse trains by the signal receiver. The Bond graph models established have shown to be useful in optimizing the design of the various constituent components within the sensing system to achieve high energy conversion efficiency under a compact size, which are critical to successful embedment within the mold structure.

• 한국농업기계학회:학술대회논문집
• /
• 한국농업기계학회 1996년도 학술발표대회 논문집
• /
• pp.1-6
• /
• 1996

A seeder monitoring system was developed to remove the uneasiness of mis-sowing that drop operations efficiency at sowing-work and to make reliable and stable work. The objectives of this study are to investigate that the system developed is applicable to sowing soybean seeds and scattering fertilizer and to evaluate performance of the system developed through the indoor test and the indoor test and the field test before it is propelled to put the system developed to practical use.

• 한국축산시설환경학회지
• /
• 제6권1호
• /
• pp.15-22
• /
• 2000

A monitoring and the forecasting system for the swine delivery was developed using CCD camera multi-function board microphone and data-recorder equipped on a personal computer. For the swine delivery monitoring and forecasting factors four factors were selected such as genitalia swine body shape breast color and sound. Image of physical variation of body shape, shape and color of genitalia area and color of breast of pregnant sow were grabbed using the CCD color camera and multi-function board and variation of voice of pregnant sow was acquired using microphone and data recorder. Acquired information of image and voice were analyzed using a custom developed algorithm and program. The result of the forecasting efficiency of swine delivery was 89%, 71% and 100% using the variation of genitalia are the body shape and the voice of pregnant sow. respectively. The efficiency of image processing was 100% for the delivery detection when the piglet was delivered half of its body from genitalia of pregnant sow, The monitoring and forecasting system informed the estimated time of the delivery of swine to a farm manager immediately if an estimated and established time set by the farm manager was the same and/or the estimated time ws earlier than the established time and the system detected the delivery.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2009년도 제40회 하계학술대회
• /
• pp.1120_1121
• /
• 2009

The remote monitoring system of this paper is a program for monitoring the temperature, voltage, and solar irradiance that made from photovoltaic(PV) system in remote area. And this monitoring system helps to check the efficiency and situation of PV system. The main subject of this paper is about making the more useful monitoring program to get and save the data from PV system. This program is monitoring the PV system by using the LabVIEW program.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2001년도 춘계학술대회 논문집
• /
• pp.560-565
• /
• 2001

Recently, machining process monitoring technique based on AE(acoustic emission) signal is used widely and becomes very important technique in machining process for improving the efficiency and the confidence of the systems. In this study, we fabricated a cheap acoustic emission sensor and monitoring system and estimated the properties of them through comparing with commercial AE sensor systems. In addition, we evaluated the performance of the fabricated sensor in polishing process. Futhermore, we are scheduled to develop the multi-point polishing process monitoring system through fabrication of the more AE sensors and complement of the monitoring system.