• Journal of Korean Society of Rural Planning
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• v.25 no.2
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• pp.15-21
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• 2019

The agricultural environment is changing and becoming more advanced due to the influence of the 4th Industrial Revolution. From the basic plan of Rural Informatics to the current level of 2nd generation smart farms aimed at improving productivity using Big data, cloud network and more IoT technology. We are continuing to provide support and research and development. However, many problems remain to be solved in order to supply and settle smart farms in Korea. The purpose of this study is to provide a method of collecting and sharing data on farming environment and to help improve the income and productivity of farmers based on collected data. In the case of hog farm, the multiple sensors for environmental data like temperature, humidity and gases and the network environment for connecting the internet were established. The environment sensor was made using the ESP8266 Node MCU board as micro-controller, DHT22 sensor for temperature and humidity, and MQ series sensors for various gases in the hog pens. The network sensor was applied experimentally for one month and the environmental data of the hog farm was stored on a web database. This study is expected to raise the importance of collecting and managing the agricultural and environmental data, for the next generation farmers to understand the smart farm more easily and to try it by themselves.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.239-244
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• 1998

ESP(Electronic Speckle Pattern Interferometry) is an optical technique to measure deforamtion of engineering components and materials in industrial areas. ESPI, a non-contact and non-destructive measuring method, is capable of providing full-field results with high spatial resolution and high speed. One of important application aspects using electronic speckle pattern interferometry is to generate contours of a diffuse object in order to provide data for 3-D shape analysis and topography measurement. The electronic speckle contouring is suitable for providing measurement range from millimeters to several centimeters. In this study, we introduce the contouring method by modified dual-beam speckle pattern interferometer and a shift of the two illumination beams through optical fiber in order to obtain the contour fringe patterns. Before the experiments, we performed the geometric analysis for dual-beam-shifted ESPI contouring. And by this geometric analysis, we performed the electronic speckle contouring experiment. We used 4-frame phase shifting method with PZT for quantitative analysis of contour fringes. Finally, we showed good agreements between the geometric analysis and experimental results.

• International Journal of Automotive Technology
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• v.8 no.2
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• pp.249-258
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• 2007

This paper proposes a method that can be used for the resistance estimation of a PWM (Pulse Width Modulation)-driven solenoid. By using estimated solenoid resistance, the PWM duty ratio was compensated to be proportional to the solenoid current. The proposed method was developed for use with EHB (Electro-Hydraulic Braking) systems, which are essential features of the regenerative braking system of many electric vehicles. Because the HU (Hydraulic Unit) of most EHB systems performs not only ABS/TCS/ESP (Electronic Stability Program) functions but also service braking function, the possible duration of continuous solenoid driving is so long that the generated heat can drastically change the level of solenoid resistance. The current model of the PWM-driven solenoid is further developed in this paper; from this a new resistance equation is derived. This resistance equation is solved by using an iterative method known as the FPT (fixed point theorem). Furthermore, by taking the average of the resistance estimates, it was possible to successfully eliminate the effect of measurement noise factors. Simulation results showed that the proposed method contained a sufficient pass-band in the frequency response. Experimental results also showed that adaptive solenoid driving which incorporates resistance estimations is able to maintain a linear relationship between the PWM duty ratio and the solenoid current in spite of a wide variety of ambient temperatures and continuous driving.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2726-2728
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• 2001

This paper describes an optimal synthesis method of binary neural network(BNN) for an approximation problem of a circular region using a newly proposed learning algorithm[7] Our object is to minimize the number of connections and neurons in hidden layer by using a Newly Expanded and Truncated Learning Algorithm(NETLA) for the multilayer BNN. The synthesis method in the NETLA is based on the extension principle of Expanded and Truncated Learning(ETL) and is based on Expanded Sum of Product (ESP) as one of the boolean expression techniques. And it has an ability to optimize the given BNN in the binary space without any iterative training as the conventional Error Back Propagation(EBP) algorithm[6] If all the true and false patterns are only given, the connection weights and the threshold values can be immediately determined by an optimal synthesis method of the NETLA without any tedious learning. Futhermore, the number of the required neurons in hidden layer can be reduced and the fast learning of BNN can be realized. The superiority of this NETLA to other algorithms was proved by the approximation problem of one circular region.

• Journal of the Korean Solar Energy Society
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• v.21 no.4
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• pp.13-20
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• 2001

The purpose of this study is to analyze the effect of Super-insulation for self-sufficient house. The process of the study is presented in the following. 1) selection reference model for simulation and verification of reference model with computer simulation program(DOE2.1E and ESP-r 9.0). 2) analysis of effect according to insulation-thickness, installed insulation position, kinds of windows, rate of infiltration, Finally, the results of this study will be to provide the most reasonable method concerned with self-sufficient house.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.231-234
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• 2007

와전류를 이용한 전위강하법은 시험체에 와전류를 비 접촉식으로 발생 시킬 수 있어 기존의 방식에 비해 결함 검출시 발생하는 오차를 줄일 수 있고 물체의 결함 검출신호의 신뢰성을 향상 시킬 수 있다. 본 논문에서는 와전류를 이용한 전위강하법의 전자기 유한요소해석을 수행하였다. 3차원 유한요소해석과정에서 해석시간을 단축시키기 위해 각 영역별로 MVP, ESP, RMSP, TMSP의 미지수 변수를 부여하여 유한요소해석을 수행하였다. 기존의 전위강하법에 와전류의 개념을 적용하기 위해서 주파수에 대한 결함 깊이의 영향과 결함에 대한 주파수에 대한 영향을 검토해본 결과 결함의 깊이가 깊어질수록 또한 높은 주파수에서 신호의 크기가 선형적으로 증가하는 패턴을 보였다. 연구결과 와전류를 이용하여 ACPD법을 시행할 경우 데이터 처리 과정과 실험 장비를 단순화 시킬 수 있어 결함 검사를 손쉽게 할 수 있을 것이라 예상된다.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.13 no.1
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• pp.5-8
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• 2007

The effects of packaging conditions on freshness extension of cucumber were investigated during 24-day storage temperatures $18^{\circ}C$ and $10^{\circ}C$. The storage life of cucumbers was influenced by both packaging methods (corrugated cardboard vs EPS box) and temperatures during storage. The fresh weigh, vitamin C content and Chlorophyll of cucumbers were decreased, while yellowing of cucumber peel was increased during storage. The change of vitamin C content was influenced by both packaging method and temperature during storage. The EPS box and low temperature were revealed to be effective treatments to extend the storability or cucumber fruit.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.2906-2910
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• 2014

This report introduces Gaussian electrostatic models (GEMs) to account for charge penetration effects in water-water interactions, allowing electrostatic interactions to be accurately described. Three different Gaussian electrostatic models, GEM-3S, GEM-5S, and GEM-6S are designed with s-type Gaussian functions. The coefficients and exponents of the Gaussian functions are optimized using the electrostatic potential (ESP) fitting procedure based on that of the MP2/aug-cc-pVTZ method. The electrostatic energies of ten different water dimers that were calculated with GEM-6S agree well with the results of symmetry-adapted perturbation theory (SAPT), indicating that this designed model can be effectively applied to future water models.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.888-889
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• 2007

와전류를 이용한 전위강하법은 시험체에 와전류를 비접촉식으로 발생 시킬 수 있어 기존의 방식에 비해 결함 검출시 발생하는 오차를 줄일 수 있고 물체의 결함 검출신호의 신뢰성을 향상 시킬 수 있다. 본 논문에서는 와전류를 이용한 전위강하법의 전자기 유한요소해석을 수행하였다. 3차원 유한요소해석과정에서 해석시간을 단축시키기 위해 각 영역별로 MVP, ESP, RMSP, TMSP의 미지수 변수를 부여하여 유한요소해석을 수행하였다. 기존의 전위강하법에 와전류의 개념을 적용하기 위해서 결함의 깊이와 주파수에 대한 영향을 검토하였다. 정확한 결함검출을 위해 검사과정을 초기검사와 정밀검사로 나누어서 실시하여 결함의 위치를 $\pm$2[mm]까지 도출해 낼 수 있었으며 결함의 폭과 크기도 어느 정도 추측해 낼 수 있었다.

• Annual Conference of KIPS
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• 2012.04a
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• pp.942-945
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• 2012

스마트 그리스 환경이 구축되어 고객과 전력회사 간 양방향 서비스가 가능하게 되면 전력회사는 고객에게 IHD나 ESP를 통해 여러 전력 서비스를 제공할 수 있게 된다. 더불어 다양한 third party 서비스 업체들도 고객의 정보를 이용한 부가 가치 사업을 개발하여 서비스하게 될 텐데 이 경우 AMI 망을 통한 안전한 정보 공유를 위해 전력망에 대한 보안 정책이 필요하게 된다. 본 논문에서는 국내 실정에 맞는 AMI 기술 개발 및 안전한 운영을 위해 AMI 보안에 관하여 기본적인 요구사항을 분석하고 보안 기능을 설계한다.