• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.4
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• pp.47-53
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• 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
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• v.7 no.3
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• pp.261-281
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• 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.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.916-918
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• 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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.821-825
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• 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.

• Journal of Korea Water Resources Association
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• v.52 no.spc2
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• pp.855-863
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• 2019

The efficiency of fishway installed in rivers can be directly evaluated by means of fish monitoring. On the other hand, when it is difficult to monitor the fish in certain conditions, or when planning a fishway, the efficiency can be evaluated indirectly through the hydraulic analysis. In this study, the hydraulic analysis technique for evaluating the efficiency of a fishway was presented. The River-2D model with the fish physical habitat module was used for the analysis of the attraction efficiency, and the weighted usable area was proposed as an index of the efficiency. In the analysis of passage efficiency, the three-dimensional model, Flow-3D, was used as an evaluation tool to describe the fluid behavior on a hydraulic structure with free surface. The ice-harbor type fishway at Baekgok weir in the Deokcheon River was selected as a test-site, and the efficiency was estimated using the hydraulic analysis. And then it was compared with fish monitoring data acquired from the river. As a result, it is difficult to replace the hydraulic analysis results with the efficiency quantitatively, but it can help to grasp the general tendency.

• Smart Structures and Systems
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• v.3 no.1
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• pp.1-22
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• 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.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06a
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• pp.1-6
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• 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.

• Journal of Animal Environmental Science
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• v.6 no.1
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• pp.15-22
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• 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.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1120_1121
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• 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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.560-565
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• 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.