• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2242-2244
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• 2004

This paper deals with the design of a reduced-order stabilizing controller for the linear system. The coupled lineal matrix inequality (LMI) problem subject to a rank condition is solved by a sequential semidefinite programming (SDP) approach. The nonconvex rank constraint is incorporated into a strictly linear penalty function, and the computation of the gradient and Hessian function for the Newton method is not required. The penalty factor and related term are updated iteratively. Therefore the overall procedure leads to a successive LMI relaxation method. Extensive numerical experiments illustrate the proposed algorithm.

• 농업과학연구
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• 제29권1호
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• pp.84-98
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• 2002

Rank of Chungnam's flower industry in Korea is sixth in the number of flower fanning household and fifth in the flower cultivating land size in 2000. However, based on the SWOT analysis of Chungnam's agro-environmental factors influencing flower growing, it is noted that further shift of the regional flower industry up to 2nd highest rank nationally can be demonstrated. Strategies for achieving such targets are suggested as follows ; 1) specializing in flower varieties with regional comparative advantage, such as orchids, lily and rose, 2) establishing the educational system for farmers to manage the risks of market price fluctuation, flower cultivation and agricultural finance properly, 3) enlarging the investments in R&D and research facilities 4) assigning the efficient function and communication among the local government, farmers and agricultural marketeers so as to increase the flower exportation.

• 한국전기전자재료학회논문지
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• 제31권6호
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• pp.398-402
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• 2018

The following conclusions were obtained after analyzing the data transmission characteristics using two frequencies and studying a system that selects data with a good reception frequency as a priority data. Data transmission and reception using two frequencies were measured at -41 to -51 dBm when the frequency was normal, and data transmitted at 900 MHz was selected as priority data. When priority frequency failure occurred, the frequency reception data of the next rank was automatically adopted, and when the frequency of the next rank was disturbed, the priority frequency search was performed again. The above results show that the use of two frequencies enables more stable data transmission and transmission, and further studies should be continued to expand the transmission and reception distances.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
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• pp.83-85
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• 2013

With an increase in the use of low rank coals in power plants, various operational issues were raised in the fuel storage and supply, combustion, boiler and flue gas treatment systems. In the fuel storage and supply system, the main issue is the self-heating propensity of low rank coals leading to spontaneous combustion in yard storage, transport and pulverization. This study evaluated the reactivity of various sub-bituminous and bituminous coals with oxygen at low temperatures by analyzing the temperature increase characteristics of coals under a constant flow rate of oxygen supply. The results were quantified to a self-heating index and the relation with the fuel properties were evaluated.

• 정보관리학회지
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• 제9권1호
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• pp.24-54
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• 1992

본 연구는 연구자들이 정보에 접근할 때 직면하고 있는 장애요소들을 종합적으로 규명하고, 규명된 장애요소들을 연구자들이 인식하고 있는 장애의 심각도에 따라 순차적으로 제시하였다. 문헌정보학 분야의 문헌, 도서관 및 정보시스템의 관리자 및 연구자들을 통해 모두 43건의 장애요소가 규명되었으며, 측정된 장애요소의 심각도 순위를 연구자의 연구분야, 연구경력 및 도서관 이용빈도별로 비교,분석하였다.

• 산업경영시스템학회지
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• 제13권21호
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• pp.61-72
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• 1990

In the past, a fundamental technique in inventory control system was to rank the items of a inventory from a distribution by value to draw an ABC curve. Unfortunately the use of ABC categorization technique has created problems and introduced some gross errors into the inventory control system. First, the author considers the possible applications of the technique in the real world and then attempts to discuss ABC fallacies through the literatures. Finally, an inventory categorization algorithm by the principal component analysis is derived and a numerical example is also presented to illustrate the algorithm.

• 대한임베디드공학회논문지
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• 제18권6호
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• pp.311-317
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• 2023

This paper presents a sliding mode observer (SMO) for reconstructing cyber attacks affecting a system. The system is first re-expressed such that its design freedom is easier to manipulate. The SMO is then used to reconstruct the cyber attack affecting the system. A simulation example is used to verify the performance of the SMO under two types of cyber attacks, and its results demonstrate the effectiveness of our proposed scheme.

• 지능정보연구
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• 제25권2호
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• pp.167-194
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• 2019

본 논문은 키워드검색광고와 관련하여 의사결정자인 광고주의 입장에서 분석한 통계모델 기반 검색엔진최적화(Search Engine Optimization)논문이다. 일반적으로 키워드입찰은 노출순위를 대상으로 하는 입찰가액에 의해 이루어지고 있다. 그런데, 대부분 광고주는 수천 개 이상의 많은 키워드를 관리함에 있어, 매시간적으로 바뀌는 키워드별 입찰가액을 통해 입찰광고시스템을 관리하고 있는데, 사실상 시간과 인력자원측면에서 비효율적이다. 따라서, 본 논문에서는 기존의 입찰가액을 중심으로 하는 입찰시스템에 대해 의문점을 제기하고, 새로운 관점에서 노출순위를 의사결정변수로 하는 새로운 검색광고모델을 재정의하여 제시하였다. 새로운 검색광고모델에 대한 최적화실증분석을 위해 예측모델과 최적화모델을 제시하였다. 연구과정은 우선 키워드의 특성에 따라 키워드그룹을 원천 제조브랜드 유통브랜드의 범주화기준을 제시한 후, PC 와 모바일 매체별로 대표 키워드 선정한 후 노출순위와 클릭률이 비선형분포임을 보였고, 통계적 관계를 검토하였다. 클릭률예측 및 입찰가액예측을 위한 통계적 시나리오를 제시하였고, 적합성 분석을 통해 최적의 예측모델을 선정한 후, 선정된 예측모델을 기반으로 하여 클릭률과 기대이익(전환율)에 관한 최적화목적함수를 정의하고 실증분석을 진행하였다. 분석결과, 본 논문에서 제시한 검색광고모델은 클릭률 기반의 클릭수와 전환율 기반의 기대이익으로 표현되는 최적화모델 모두에서 개선효과가 있음을 확인하였다. 다만, 기대이익 최적화모델의 경우에는 핵심키워드임에도 불구하고 기대이익이 낮아 광고에서 배제되는 문제를 있음을 확인하고 대안을 제시했다. 마코브체인분석을 통해 핵심 경유키워드 개념을 도입하였고, 최적화목적함수에 대해 핵심경유키워드의 기회이익을 반영한 최적화수정모델을 제시하여 적용가능성을 확인하였다. 본 논문은 키워드입찰시스템의 의사결정변수를 노출순위의 관점으로 전환하는 새로운 모델을 제안하였고, 키워드 범주별 및 노출순위 기반의 통계적 예측을 제시하고, 포트폴리오 구성에서의 최적화실증분석을 통해 노출순위 기반 예측모델의 유효성을 확인함과 동시에, 키워드간의 확산효과를 포함하는 수정모델제시 등 전략적인 입찰을 제안한 점에 시사점이 있다.

• 한국의류학회지
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• 제36권7호
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• pp.767-777
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• 2012

This study analyzed the system and arguments on the light-pink official uniforms and investigated the backgrounds and principles on the changes of the Sibok system. A study on light-pink danryeong in the latter part of the Joseon Dynasty is a de facto study on Sibok since the name of the light-pink official uniforms (implemented at the time of King Seonjo) changed from Sangbok to Sibok. Sangbok is discussed to explain the name change from Sangbok to Sibok and distinguish their usages; in addition, Gongbok is examined to understand the characteristics of the Sibok system. The Annals of the Joseon Dynasty (books written by scholars) and related laws are used as research materials. The research results are as follows. The name of the light-pink uniforms (a custom before the Japanese invasion in 1592) changed from Sangbok to Sibok at the time of King Gwanghaegun and the light-pink uniform was used as a relatively light formal uniform compared to Sangbok. Sibok was added to the law Sok-dae-jeon at the time of King Yeongjo (because the king respected the custom) and its color rank system was denoted from light-pink and red. Sibok was revised to light-pink, blue, and green under the law Dae-jeon-tong-pyeon that was promulgated at time of King Jeongjo. In the development of the Sibok system in the latter part of the Joseon Dynasty, the color rank system of Gongbok was reflected. The sovereign ideas in the official uniforms in the latter part of the Joseon Dynasty (revealed in the study of the system and arguments on the light-pink official uniforms) were the thoughts that respected the custom and the principles that distinguish ranks to establish a Confucian based hierarchy.

• 동력기계공학회지
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• 제19권1호
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• pp.56-63
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• 2015

In this study, the exhaust characteristics of the diesel engine for the change of the mixing ratio of biodiesel fuel were quantitatively analyzed by using the numerical analysis method. As the fuel used in the experiment, the diesel and biodiesel(waste oil, soybean oil), the mixed fuel BD2(Diesel only), BD3, BD5, BD20, BD50 and BD100 were used. The injection pressure($p_{inj}$) was set to 400bar, 600bar, 800bar, 1000bar and 1200bar as the experimental variable. Also the concept of the standard deviation, Pearson's correlation coefficient and Spearman rank-order correlation coefficient based on the statistics was introduced in order to analyze the exhaust characteristics of the quantitative NOx and Soot according to the injection pressure and the mixing ratio variation of biodiesel blending fuel. It is considered that as a result of studies, for the waste oil, NOx and Soot can be simultaneously reduced through control of the mixing ratio at the regions of $p_{inj}=400bar$ and $p_{inj}=600bar$, and the Soot can be reduced without affecting on the emission of NOx at more than $p_{inj}=800bar$. For the soybean oil, NOx and Soot can be simultaneously reduced at $p_{inj}=400bar$ and the Soot can be reduced without affecting on the emission of NOx at $p_{inj}=600bar$.