• Journal of the Korean Geotechnical Society
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• v.24 no.10
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• pp.83-91
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• 2008

Previous settlement prediction methods based on settlement monitoring were developed under instantaneous loading condition and have restriction to be applied to soft ground under ramp loading condition. In this study, settlement prediction method under ramp loading was developed. New settlement prediction method under ramp loading considered influence factors of consolidation settlement such as thickness of clayed layer, quantity of surcharge load and preconsolidation pressure, etc. Geometrical correction method based on hyperbolic method (1991) and correction method based on probability theory were applied to increase accuracy of settlement prediction using field monitoring data after ramp loading. Large consolidation tests for ideally controlled one dimensional consolidation under ramp loading condition were performed and the settlement behavior was predicted based on the monitoring data. New prediction method yielded good result of entire settlement behavior by using data during an early stage of ramp load. Additionally, new prediction method offered better settlement prediction which had final settlement prediction in close proximity and low RMSE(Root Mean Square Error) than previous method such as hyperbolic method did.

• Development and Reproduction
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• v.5 no.1
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• pp.73-79
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• 2001

Recently many studies have reported that total and bioavailable androgens reduced in male and female athletes and that physical exercise reduces the body weight and increases the reproductive abnormalities such as oligomenorrhea, anovulation, inadequate luteal phase, and delayed puberty in women by the inhibition of the hypothalamic-pituitary-gonadal (HPG) axis . In addition, high mileage endurance 겨nning, psychological stress, and military endurance training in men also reduce the secretion of reproductive hormones. To investigate the efffcts of physical endurance exercise on the secretion of reproductive hormones in men, androgenic hormones from adrenal glands and testis were measured in serum by the conventional radioimmunoassays after long-term (more than3 months), short-term (1 week), and acute (1${sim}$2 hours) physical exercises. Androgenic hormones from adrenal glands and testis such as total testosterone (TT), free testosterone (fT), dehydroepiandrosterone (DHEA), and androstenedione (A) decreased after thesestrenuous endurance trainings, whereas ACTH, cortisol, and dehydroepiandrosterone sulfetes (DHEAS) increased. Conadotropins (LH and FSH) were not idluenced by the physical exercises. Based upon the present results, we assume that the decrease in adrenal and testicular androgens by physical endurance exercises might be associated with the reproductive abnormalities in athletes by unknown factor(s) in addition to the HPG axis disturbance.

• Journal of Intelligence and Information Systems
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• v.26 no.4
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• pp.127-148
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• 2020

The data center is a physical environment facility for accommodating computer systems and related components, and is an essential foundation technology for next-generation core industries such as big data, smart factories, wearables, and smart homes. In particular, with the growth of cloud computing, the proportional expansion of the data center infrastructure is inevitable. Monitoring the health of these data center facilities is a way to maintain and manage the system and prevent failure. If a failure occurs in some elements of the facility, it may affect not only the relevant equipment but also other connected equipment, and may cause enormous damage. In particular, IT facilities are irregular due to interdependence and it is difficult to know the cause. In the previous study predicting failure in data center, failure was predicted by looking at a single server as a single state without assuming that the devices were mixed. Therefore, in this study, data center failures were classified into failures occurring inside the server (Outage A) and failures occurring outside the server (Outage B), and focused on analyzing complex failures occurring within the server. Server external failures include power, cooling, user errors, etc. Since such failures can be prevented in the early stages of data center facility construction, various solutions are being developed. On the other hand, the cause of the failure occurring in the server is difficult to determine, and adequate prevention has not yet been achieved. In particular, this is the reason why server failures do not occur singularly, cause other server failures, or receive something that causes failures from other servers. In other words, while the existing studies assumed that it was a single server that did not affect the servers and analyzed the failure, in this study, the failure occurred on the assumption that it had an effect between servers. In order to define the complex failure situation in the data center, failure history data for each equipment existing in the data center was used. There are four major failures considered in this study: Network Node Down, Server Down, Windows Activation Services Down, and Database Management System Service Down. The failures that occur for each device are sorted in chronological order, and when a failure occurs in a specific equipment, if a failure occurs in a specific equipment within 5 minutes from the time of occurrence, it is defined that the failure occurs simultaneously. After configuring the sequence for the devices that have failed at the same time, 5 devices that frequently occur simultaneously within the configured sequence were selected, and the case where the selected devices failed at the same time was confirmed through visualization. Since the server resource information collected for failure analysis is in units of time series and has flow, we used Long Short-term Memory (LSTM), a deep learning algorithm that can predict the next state through the previous state. In addition, unlike a single server, the Hierarchical Attention Network deep learning model structure was used in consideration of the fact that the level of multiple failures for each server is different. This algorithm is a method of increasing the prediction accuracy by giving weight to the server as the impact on the failure increases. The study began with defining the type of failure and selecting the analysis target. In the first experiment, the same collected data was assumed as a single server state and a multiple server state, and compared and analyzed. The second experiment improved the prediction accuracy in the case of a complex server by optimizing each server threshold. In the first experiment, which assumed each of a single server and multiple servers, in the case of a single server, it was predicted that three of the five servers did not have a failure even though the actual failure occurred. However, assuming multiple servers, all five servers were predicted to have failed. As a result of the experiment, the hypothesis that there is an effect between servers is proven. As a result of this study, it was confirmed that the prediction performance was superior when the multiple servers were assumed than when the single server was assumed. In particular, applying the Hierarchical Attention Network algorithm, assuming that the effects of each server will be different, played a role in improving the analysis effect. In addition, by applying a different threshold for each server, the prediction accuracy could be improved. This study showed that failures that are difficult to determine the cause can be predicted through historical data, and a model that can predict failures occurring in servers in data centers is presented. It is expected that the occurrence of disability can be prevented in advance using the results of this study.

• Korean Journal of Mineralogy and Petrology
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• v.34 no.3
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• pp.157-167
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• 2021

Lead (Pb) is one of the key trace elements, exhibiting a peculiar partitioning behavior into silicate melts in contact with minerals. Partitioning behaviors of Pb between silicate mineral and melt have been known to depend on melt composition and thus, the atomic structures of corresponding silicate liquids. Despite the importance, detailed structural studies of Pb-bearing silicate melts are still lacking due to experimental difficulties. Here, we explored the effect of lead content on the atomic structures, particularly the evolution of silicate networks in Pb-bearing sodium metasilicate ([(PbO)_x(Na₂O)_1-x]·SiO₂) glasses as a model system for trace metal bearing natural silicate melts, using ²⁹Si solid-state nuclear magnetic resonance (NMR) spectroscopy. As the PbO content increases, the ²⁹Si peak widths increase, and the maximum peak positions shift from -76.2, -77.8, -80.3, -81.5, -84.6, to -87.7 ppm with increasing PbO contents of 0, 0.25, 0.5, 0.67, 0.86, and 1, respectively. The ²⁹Si MAS NMR spectra for the glasses were simulated with Gaussian functions for Qⁿ species (SiO₄ tetrahedra with n BOs) for providing quantitative resolution. The simulation results reveal the evolution of each Qⁿ species with varying PbO content. Na-endmember Na₂SiO₃ glass consists of predominant Q² species together with equal proportions of Q¹ and Q³. As Pb replaces Na, the fraction of Q² species tends to decrease, while those for Q¹ and Q³ species increase indicating an increase in disproportionation among Qⁿ species. Simulation results on the ²⁹Si NMR spectrum showed increases in structural disorder and chemical disorder as evidenced by an increase in disproportionation factor with an increase in average cation field strengths of the network modifying cations. Changes in the topological and configurational disorder of the model silicate melt by Pb imply an intrinsic origin of macroscopic properties such as element partitioning behavior.

• Food Science and Industry
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• v.55 no.2
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• pp.188-202
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• 2022

In the insect industry, as the scope of application of insects is expanded from pet insects and natural enemies to feed, edible and medicinal insects, the demand for quality control of insect raw materials is increasing, and interest in securing the safety of insect products is increasing. In the process of expanding the industrial scale, controlling the temperature and humidity and air quality in the insect breeding room and preventing the spread of pathogens and other pollutants are important success factors. It requires a controlled environment under the operating system. European commercial insect breeding facilities have attracted considerable investor interest, and insect companies are building large-scale production facilities, which became possible after the EU approved the use of insect protein as feedstock for fish farming in July 2017. Other fields, such as food and medicine, have also accelerated the application of cutting-edge technology. In the future, the global insect industry will purchase eggs or small larvae from suppliers and a system that focuses on the larval fattening, i.e., production raw material, until the insects mature, and a system that handles the entire production process from egg laying, harvesting, and initial pre-treatment of larvae., increasingly subdivided into large-scale production systems that cover all stages of insect larvae production and further processing steps such as milling, fat removal and protein or fat fractionation. In Korea, research and development of insect smart factory farms using artificial intelligence and ICT is accelerating, so insects can be used as carbon-free materials in secondary industries such as natural plastics or natural molding materials as well as existing feed and food. A Korean-style customized breeding system for shortening the breeding period or enhancing functionality is expected to be developed soon.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.3
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• pp.65-74
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• 2017

There have been questions how entrepreneurs think, act and why individuals become entrepreneurs. The trait-based explanation of entrepreneurial activities has been main stream. However, the trait-based theory has been criticized because it assumes that entrepreneurial traits are inherited, stable and enduring over time. This research accepts the cognitive theory to see how entrepreneurs learn or accept others' values, how entrepreneurial perceptions of opportunity impact entrepreneurial actions and how individuals acquire the social legitimation of the formation of entrepreneurial activities. In order to capture the attitudes, activities and motivations of people who are involved in entrepreneurial activities, the author uses the GEM Korea 2016 data. The data from the Global Entrepreneurship Monitor(GEM) has been well known for the data to capture individuals early-stage entrepreneurial activities. This paper used the sample from the APS(Adult Population Survey) of the GEM which was completed by a representative sample of two thousand adults in Korea by the qualified survey vendor, with strict procedures and oversight by the GEM central data team. The hypotheses are tested with logit regression analysis to estimate the probability of the influence of perceptual variables such as individual perception in social learning, the opportunity recognition in the environment, and social legitimation in the entrepreneurial activities. Based on the results, individuals tend to have high entrepreneurial activities if individuals have high self-efficacy. Also, the existence of role models around the entrepreneurs encourages the individuals involve in entrepreneurial activities more however the perception of opportunity in the environment is not strongly associated with entrepreneurial activities. The media exposure of successful entrepreneurs is more important than others' perception of entrepreneurs on the desirable career option or respect from communities. This paper can contribute to the cognitive processes, particular perception about oneself, as well as perception which is impacted by a community or a society.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.923-927
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• 2006

국내의 수자원장기종합계획(건교부, 2001년)에 의하면 농업용수는 우리나라 수자원의 48%를 차지하고 있으며 하천유지용수를 제외한 이용량으로 보면 62%에 해당하는 최대 용수이용 부문이다. 그러므로, 농업용수의 효율적인 계획과 관리는 우리나라 수자원의 효율적인 이용에 있어서 매우 중요하다. 우리나라의 농촌은 1970년 이후 급격한 도시화, 산업화로 농업인구의 격감과 노동력의 부족에 따른 농업용 기계가 보급되게 됨에 따라, 과거의 주로 인력에 의한 벼농사의 영농방식에 변화가 생기게 되었다. 그러한 영농전반의 변화들은 직파재배, 집단육묘, 비닐하우스를 이용한 못자리, 어린모 이앙법 등 다양한 방식으로 벼재배 방식에서도 나타나고 있다. 이러한 영농상황의 변화는 농업용수공급 현황에도 영향을 미쳐 물이용 형태가 과거와 많은 차이를 보임을 알 수 있다. 이러한 차이는 최근의 연구결과에서도 나타나고 있는데 2002년 농어촌연구원 '용수수급의 안정성 제고 연구 및 종합시험지구 운영'에 의하면 3개 저수지지구의 계획공급량과 용수공급량 비율이 $0.7{\sim}1.3$이며, 영농초기 $4{\sim}5$월에 특히 차이가 큼을 알 수 있었다. 2001년 한국건설 기술연구원의 '물관리 효율성 제고기술 연구보고서'에 의하면 $4{\sim}5$월에 큰 차이를 보이는 등 농어촌연구원과 비슷한 결과를 나타내었다. 본 연구는 중부지방인 경기 남부지역을 대상으로 영농방식에 대한 조사를 하고 농업용수 공급량을 측정하여 현행 농업용수량 산정기준에 의한 농업용수량과 비교함으로써 변화된 영농환경을 고려한 적정한 관개 용수량 산정방법을 제시하는 것을 목적으로 하고 있다.악할 수 없었던 수체내의 많은 특징을 파악 할 수 있었다.. 중랑천 유역의 소배수구역을 대상으로 연중 발생하는 큰 호우사상에 대해 임의의 강우관측소를 결측지점으로 가정하고 주변의 강우관측소로부터 각각의 방법을 이용해 가중치들을 산정하여 결측지점의 강우량 값을 보정하고자 하였다. 또한 각각의 방법을 이용하여 얻어진 결과에 대해 실측값과 보정값의 오차정도를 평균절대오차법(Mean Absolute Error)과 제곱평균제곱근오차법(Root Mean Squared Error)에 의해 산정하여 보정 방법간의 효율성을 검토하고자 하였다.9년, 그리고 2010년${\sim}$2019년까지 총 4구간으로 나누어 결과를 도출하였으며 예상한 바와 같이 후반기 20년 동안에 세 가지 지표가 취약해 지는 것을 확인할 수 있었고, 특히 2000년부터 2009년까지 10년 동안에는 더욱 취약해짐을 확인할 수 있었다.를 보임에 따라 그 정책적 효과는 때로 역기능적인 결과로 초래하였다. 그럼에도 불구하고 이 연구결과를 통하여 최소한 주식시장(株式市場)에서 위탁증거금제도는 그 제도적 의의가 여전히 있다는 사실이 확인되었다. 또한 우리나라 주식시장에서 통상 과열투기 행위가 빈번히 일어나 주식시장을 교란시킴으로써 건전한 투자풍토조성에 저해된다는 저간의 우려가 매우 커왔으나 표본 기간동안에 대하여 실증분석을 한 결과 주식시장 전체적으로 볼 때 주가변동율(株價變動率), 특히 초과주가변동율(超過株價變動率)에 미치는 영향이 그다지 심각한 정도는 아니었으며 오히려 우리나라의 주식시장은 미국시장에 비해 주가가 비교적 안정적인 수준을 유지해 왔다고 볼 수 있다.36.4%)와 외식을 선호(29.1%)${\lrcorner

• Journal of KSNVE
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• v.5 no.3
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• pp.275-283
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• 1995

본 글에서는 지능구조물의 개념설명과 더불어 ERF의 특성, ERF를 함유란 함유 한 지능구조물 시스템의 구성, 동적 모델링과 진동제어 그리고 그 응용성에 관한 연구 현황과 방향에 대해 살펴보았다. 설명한 바와 같이 지능구조물은 새로운 차원의 신생 하는 첨단분야로서, 소음 및 진동에 관련된 무한한 잠재력과 다양한 응용성으로 미루 어 볼때 아주 매력적인 연구 분야이다. 그러나, 여러 응용 시스템의 상품화 단계로의 도약에 있어서 각 시스템 구성 요소 분야별 해결해야할 연구 사항들이 있다. 먼저, 액추에이팅을 수행하는 ERF 자체의 내구성 문제로서 고온에서 ERF의 효과 하락과 장시간 사용시 ERF에 의한 마멸, 고체 입자의 침전에 의한 초기 상태 불안정 등이 있다. 아울러 기존의 장치의 성능을 능가하기 위해 보다 큰 효과를 나타내는 새로운 차원의 ERF개발이 요구된다. 그리고 센서기술 분야에서는 호스트 재료에 보다 쉽게 결합이 되고 여러가지 형태의 요구조건을 만족시킬 수 있으며 외부 환경조건에 강건 하고 다양한 센서 개발이 요구된다. 또한, 보다 일번적인 동적 모델링을 통해 적용 시스템에 적합하고 강건한 제어기에 대한 연구가 진행되어야 한다. 마지막으로 능동 제어기를 실제로 구현하기 위한 호스트 재료 각 요소마다 센서의 설치, 페회로 피드백 시스템 장착, 상호간의 인터페이스 등의 기술 발전이 요구되며, 아울러 보다 효율적 인 시스템의 성능 특성을 실현할 수 있는 호스트 재료와 기계 메카니즘이 필요로 된다. 이상의 설명에서 알 수 있듯이 지능구조물에 대한 연구는 어느 한 분야에서만 아니라 기계, 전기전자, 토목, 물리, 재료과학 등 통합형식에 의한 접근 방향으로 추진되어야 할 것이다.서 세탁기의 진동 소음을 저감시키기 위해 진동 소음원에 대해 논술하고, 진동해석을 위해 컴퓨터 시뮬레이션 결과를 이용한 저진동 기술 개발에 대하여 기술하고자 한다.rotary piston)식 압축기는 약 20여년 전 부터 냉방용 압축기에서부터 널리 쓰이게 되었다. 약 10여년전부터 상용화 된 스크롤(scroll) 형 압축기도 현재 상대적으로 용량이 큰 가정용 냉방기를 중심으로 많이 쓰이고 있다. 스크류형 압축기는 보통 중대형 상업용에 주로 쓰인다. 해결하려 하였고, 수치해석은 피스톤의 운동을 배제한 단순화한 흡배기계의 정상상태 유동해석이 주를 이루어왔다. Taghaui and Dupont 등[5]은 KIVA코드를 사용하여 흡기포트와 연소실 그리고 밸브의 움직임을 동시에 고려한 수치해석을 도입하였다. 하지만 이들이 밸브의 운동을 고려하기 위해 사용한 이동격자는 격자점은 시간에 따라 변화하지만 그 격자의 수가 일정하게 유지되어 있어서 밸브의 완전개폐를 해석할 수가 없다. 강희정[6]은 단일 실린더와 단일 배기밸브를 갖는 문제로 단순화하여 피스톤과 밸브의 움직임을 고려하므로써 배기행정 후 소음이 어떻게 전파해 나가는가를 연구하였다. 본 연구에서도 최소밸브간격과 최대밸브간격 사이에서만 계산이 가능하나 흡기의 경우는 밸브가 닫힐 때 생기는 압력파가 중요하므로 실린더와 밸브사이에 벽면조건을 주어 밸브의 개폐를 모사하였다.술을 보유하고자 한다. 이용한 해마의 부피측정은 해마경화증 환자의 진단에 있어 육안적인 MR 진단이 어려운 제한된 경우에만 실제적 도움을 줄 수 있는 보조적인 방법으로 생각된다.ofile whereas relaxivity at high field is not affected by τS.

• Journal of the Korean Society for Library and Information Science
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• v.50 no.4
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• pp.283-310
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• 2016

The present study aims to develop measures to enhance user service at Chungnam Representative Library by establishing Chungnam Representative Library Operation Master Plan. To this end, I conducted a literature review, analysis of services of other representative libraries, and a survey. The study results suggested six measures for user service enhancement. The first measure is space-specific programs, such as children's materials room, general materials room, electronic materials room, auditorium, multipurpose room, outdoor stage, exhibition room, and book café. The second measure is the services specific user types, such as children, adolescents, adults, the disabled, and multicultural families. The third measure is information service specific for information type, such as print material service and digital material service. The fourth measure is the service for the Information-Poor including the expansion of mobile library service, the service for information users in special environment, and the development of mobile library rules. Fifth measure is information service for Chungcheongnam-do residents, such as Baekje Studies specialized service that incorporates local characteristics, specialized information service for Chungcheong Studies and local materials, and information service for administrative and policy materials. The last measure is the measure to secure initial users and early stage service enhancement.

• Environmental and Resource Economics Review
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• v.21 no.3
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• pp.595-625
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• 2012

Recently environment-friendly pellet boilers have interests as emissions of greenhouse gases are regulated internationally and energy security becomes more important to oil addicted countries including Republic of Korea. But the Korean market for pellet boilers is on the initial stage due to the high production costs relative to other conventional boilers. Hence the Korean government has supported financially and promoted the pellet boiler business. In this sense, it would contribute market stratergy and effective promotion policy for both of the government and private companies if we can forecast market shares of pellet boilers appropriately. For this purpose, this study surveyed potential consumers' preferences on pellet boilers among various alternatives using a choice experiment reflecting intangible costs. As the market share of new technology increases, intangible costs decline. According to different intangible cost scenarios, we experimented people's preferences on oil, gas, electric, and pellet boilers. A multinomial logit model was employed to estimate coefficient parameters of common attributes for various alternative boilers. Based on the estimates, we forecasted market shares of individual boilers. We found that as intangible costs decline, the market share of pellet boiler increase substantically while market shares of electric and gas boilers decrease dramatically. The market share of oil boiler did not change significantly. Meanwhile, as people are more rich, more educated, and exposed to advertisement on pellet boilers, the likelihood of choosing the pellet boiler increases.