• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.149-154
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• 2005

최근에 이르러 농촌 인구의 도시유입으로 도시의 주거공간이 절대적으로 부족해지고 있으며, 이는 대도시의 아파트 가격 상승을 유발하는 등 부수적인 사회/경제적 문제를 일으키고 있다. 정부나 지방자치단체에서는 이러한 문제를 해결하기 위하여 대규모의 신도시 개발계획을 추진하고 있으며, 이러한 신도시 개발은 도시화로 인하여 환경적, 수문학적으로 부정적인 영향을 미치는 것으로 조사되고 있다. 도시화는 수문학적으로 산림이나 농경지와 같은 투수지역을 건물, 도로 등의 불투수지역으로 변화시키는 것이며 (Im 등, 2003), 이로 인하여 홍수파의 도달시간이 줄어들고 첨두유량이 증가하는 등의 수문변화를 수반하게 된다. 도로나 건물 등이 대부분을 차지하고 있는 도시지역에서는 지표면이나 식생으로부터 대기중으로 방출되는 증발산량이 농촌이나 산림지역보다 상대적으로 적으며, 강우시 토양중의 침투량과 지표면의 저류량도 도시지역에서는 매우 적게 나타난다. 신도시 개발 전후의 수문순환을 평가하는 방법 중의 하나는 개발예정지에 대한 장$\cdot$단기의 수문/수질 관측을 통하여 개발 전과 개발 후의 유출특성과 수질부하를 정량적으로 비교하는 것이다. 본 연구에서는 도시화로 인하여 대규모의 토지이용 변화가 예상되는 신도시 개발예정지구를 시험유역으로 선정하여 장기적인 수문/수질 모니터링을 실시하고자 한다. 또한, 시험유역에서 계측된 자료와 유역수문모형을 활용하여 개발전후의 홍수 및 유출특성을 분석하고 도시화가 하천의 수문 및 수질에 미치는 영향을 정량적으로 비교분석 함으로써 효율적인 저감 대책의 수립에 활용할 계획이다. 본 연구에서는 국내$\cdot$외의 시험유역의 운영 실태를 조사하고, 신도시 개발 등으로 인하여 급격한 도시화가 진행되고 있는 지구를 시험유역으로 선정하여 유역의 물순환 체계를 조사하고자 한다. 이를 위하여 신도시 개발지구와 도시정비사업지구를 대상후보지로 선정하여 개발계획 및 유역의 특성 등을 조사하고, 시험유역의 선정기준을 수립하여 연구의 목적과 부합되는 지구를 시험유역으로 선정하였으며 선정된 시험유역에 대하여 수문$\cdot$수질 조사 계획을 수립하고, 계측시설을 설치하여 시험운영을 실시하고, 향후 시험유역의 수문계측 및 관리방안을 수립하고자 한다.

• Polymer(Korea)
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• v.38 no.3
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• pp.272-277
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• 2014

We studied in-line monitoring the dispersion of highly energetic material simulant by a twin screw extruder having a high temperature ultrasonic system. The simulant suspension system consisted of ethylene vinyl acetate and Dechlorane plus 25 as binder and filler, respectively. With increasing filling fraction, the ultrasonic velocity was not changed but the attenuation linearly decreased. It was possible to estimate the solid fraction of well dispersed suspension system by measuring ultrasonic attenuation. The ultrasonic attenuation of samples filled over 60 v% approached straight line with increasing filling fraction when the samples was extruded repeatedly. It was due to the enhanced dispersion of solid particles in the suspension system. It was believed that the degree of dispersion and filling fraction could be obtained by combination of on-line measurement like ultrasonic attenuation and off-line analysis like TGA and SEM with image analyzer.

• Korean journal of applied entomology
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• v.50 no.3
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• pp.209-214
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• 2011

Changes in insect communities are one of the best indicators of environmental changes. A survey was conducted using the Flight Interception Trap (FIT) method to check the changes of species composition and abundance of silphids at Mt. Sokrisan National Park from April to October in 2003 to 2007. A total of 9,704 individuals of six silphid species were examined by FIT. Among them, Nicrophorus quadripunctatus was the most dominant species with 8,763 (90.3%) individuals. There were only 971 (9.7%) individuals of the other five species. The seasonal abundance of silphids peaked in July and August. The annual abundance has decreased gradually since 2004. Therefore, the changing patterns of species composition and abundance of silphids checked by long-term monitoring could be used as environmental indicators which indirectly show the environmental changes of Mt. Sokrisan National Park.

• The Korean Journal of Applied Statistics
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• v.34 no.5
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• pp.735-744
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• 2021

Maintaining the lifetime of a product is one of the objectives of quality control. In real processes, most samples are constructed with censored data because, in many situations, we cannot measure the lifetime of all samples due to time or cost problems. In this paper, we propose two cumulative sum (CUSUM) control charting procedures to monitor the mean of type I right-censored lognormal lifetime data. One of them is based on the likelihood ratio, and the other is based on the binomial distribution. Through simulations, we evaluate the performance of the two proposed procedures by comparing the average run length (ARL). The overall performance of the likelihood ratio CUSUM chart is better, especially this chart performs better when the censoring rate is low and the shape parameter value is small. Conversely, the binomial CUSUM chart is shown to perform better when the censoring rate is high, the shape parameter value is large, and the change in the mean is small.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.11
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• pp.1515-1522
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• 2008

Monitoring the pesticide residues in agricultural products is essential to protect consumers, obtain data for risk assessment, and ensure fair trade practices. We developed a multi-residue method for the analysis of 37 pesticides with different physico-chemical properties in agricultural products and analyzed the amount of pesticide residues on about 1,000 samples circulated in South Korea. The samples consisted of 26 different types of agricultural products selected at markets in 14 major cities; cereals (2 species), nuts (1 species) potatoes (1 species), beans (2 species), fruits (3 species), vegetables (16 species), and mushrooms (1 species). In this study, residual pesticides were detected in 23 samples (2.2%) and one sample was detected to be over maximum residue limits (MRLs, 0.1%) for pesticides in foods by the Korea food code. In leafy vegetables such as pepper leaves, radish leaves, cham-na-mul, shin-sun-cho, crown daisy, chwi-na-mul and citrus fruits such as kumquat, 8 kinds of pesticides were detected. Specially, diazinon were detected over MRLs and also, endosulfan, ethoprophos and phenthoate were detected frequently. Based on these results, we investigated the risk assesment from amount of residual pesticide, total %ADI was 1.262%, but the value has not effected on human health.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.4
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• pp.227-234
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• 2005

In this paper, a smart wireless MEMS-based accelerometer(MA) system has been designed and experimented for smart monitoring system of civil structures. Various performance and experimental tests have been carried out to evaluate whether this system is suitable for monitoring system of civil structures. First, we examined its sensitivity, resolution, and noise, specifically to evaluate the performance of the smart wireless MA system. The results of experiments enabled us to estimate performance of the MA in SWMAS in comparison to the value of data sheet from MA. Second, characteristics of model structure were analyzed by the ambient vibration test based on the NExT combined with ERA. Finally, this analysis was compared to the one that was made by FE results, and the comparison proved that a smart wireless MA system was fitted in smart monitoring system effectively.

• Journal of Software Engineering Society
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• v.28 no.2
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• pp.1-6
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• 2019

There are various stakeholders in the blockchain ecosystem. Since the emergence of Ethereum, many transactions have been made using smart contracts, and a wider range of stakeholders are participating, including not only developers, but also investors, banks, companies, and general users. However, various stakeholders have a problem in that it is difficult and complicated to check the state of smart contracts. If it becomes difficult to check the state, the reliability of the smart contract will be lowered and the utilization will be lowered. Also, if the state check is difficult and complicated for the developer, it will be difficult to provide high quality due to the difficulty of testing and debugging the smart contract developed by the developer. In this research, we propose a design and implementation method of the Ethereum Smart Contract State Monitoring System that enables various stakeholders and developers to easily and continuously check the state of smart contracts and analyze them using historical data.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.2
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• pp.117-127
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• 2008

Korea has a large number of landslides due to localized torrential downpours and typhoons in summer, causing great human damage and economic losses. In particular, most roads in the Gangwon area are located in mountains, making them expose to a great risk of landslide. Therefore, it is urgent to prepare countermeasures to prevent these landslides. Necessary for that are various slope investigation and high-tech observation techniques for slope maintenance. Recently there have been slope observation techniques using optical fiber sensors, GPS, CCD cameras, Total Station and satellite images; however, these are not used much due to poor economic feasibility, low accuracy and efficiency. This study evaluated accuracy of displacement extraction of model slopes using terrestrial LiDAR to determine its application to landslide monitoring. As a result, it can measure several mm of minute displacement with high accuracy and help to rapidly obtain geographical features of slope.

• Journal of KIISE:Software and Applications
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• v.36 no.11
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• pp.920-927
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• 2009

In this paper, we developed a system that could assist appropriate activities for medication compliancy of the elderly. It employs a proactive knowledge which is represented as XML templates predefined for their medication activities. The knowledge-based assistance depends on the contexts considerably, which the system can recognize by continuously monitoring the current position and the time-schedule for their medications. The monitoring can be performed with ultrasonic sensors and infrared sensors mounted in a display and a pillbox respectively. According to the recognized contexts, the medication activities required by the elderly can be serviced through user-friendly multimedia display. In special, our experiment evaluates that the developed system is able to enhance the medication compliancy of chronic disease patients.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1843-1847
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• 2008

국토해양부는 수자원 상황을 효율적으로 모니터링하기 위하여 하천수 관리자, 하천수 사용자 및 일반 국민에게 하천유량, 사용량 및 기타 수문정보를 실시간으로 제공할 수 있는 모니터링 시스템을 시범 구축하였다. 향후 유역 물수지, 하천갈수상황을 분석할 수 있는 시스템을 추가하여 전국의 하천유량을 실시간으로 모니터링하고 관리하기 위하여 실시간 물관리시스템 구축을 추진 중에 있다. 구축된 실시간 물관리 시스템의 효율적 운영을 위해서는 하천 유량 등 수문정보와 더불어 하천 취수량 정보가 필수적이다. 본 연구에서는 실시간 물관리의 핵심자료인 하천수사용량을 실시간 수집할 수 있는 "영상을 이용한 실시간 하천수사용량 수집시스템"을 개발하였다. 개발된 시스템은 유량계 혹은 전력량계를 통해 표출되는 관련정보를 CCTV 카메라로 촬영하여 영상을 취득하고, 문자인식 알고리즘을 활용 수치로 변환하여 사용량을 제공해 주는 시스템이다. 관리자는 영상을 촬영한 후 문자로 인식된 사용량 주서버에 전송하여 저장하기 때문에 사용량과 함께 현장상황을 확인할 수 있다. 개발한 시스템은 다양한 형태의 유량계, 전력량계로 구성되어 있는 계측시설에 대해 적용이 용이하고, 기존 유량계 등을 그대로 활용하여 자료를 수집할 수 있기 때문에 저비용으로 하천수사용량 자료를 수집 관리할 수 있다. 현재 국토해양부에서는 "하천법"에 근거하여 용도별 일정규모이상의 하천수사용자에 대해 일사용량을 월별로 수집하고 있으나, 자발적인 선사용 후보고 체계로 객관성확보가 어렵고 실시간 물관리를 위한 자료로 활용이 곤란한 상황이다. 그러나, 본 시스템을 통해 하천수사용량을 수집할 경우 실시간으로 수치화된 사용량과 영상자료가 전송되어 서버에 저장할 수 있어 객관성을 확보하고 활용도를 높일 수 있는 장점이 있다. 본 시스템은 한강 홍수통제소 관할 허가지점에 3개소, 금강 관할 허가지점에 1개소에 시험적용하여 평가한 결과, 저비용으로 하천수 취수량을 효과적으로 수집할 수 있는 것으로 평가되었다.