• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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• pp.145-147
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• 2005

In present, most of metallic structures(gas pipeline, oil pipeline, water pipeline, etc) are running parallel with subway and power line in seoul. Moreover subway system and power line make a stray current due to electrical corrosion on metallic structures. The owner of metallic structures has a burden of responsibility for the protection of corrosion and the prevention against big accident such as gas explosion or soil pollution and so on. So, they have to measure and analyze the data about P/S(Pipe to Soil) potential due to stray current of subway system. So, we have developed the Real-time Wireless Remote Monitoring System for Stray Current of Subway System. In this system, the permanent buried type reference electrode is necessary. In this paper, results of development of buried type reference electrode using porous ceramic$({\alpha}-Al_{2}O_{3})$ are presented.

• 한국정보처리학회논문지
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• 제2권3호
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• pp.425-432
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• 1995

본 논문에서는 VLSI 회로망의 데스트 패턴 생성에 적합한 범용 자동 데스트 패턴 생성기(UATPG)의 설계 및 구현 기법을 기술하고자 한다. UATPG는 기존 ATPG의 용량을 확장하고 CAD 사용자에게 편리한 설계 환경을 제공하는데 초점을 맞추어 구현되었다. 테스트 패턴 생성시에 함수적 게이트의 신호선 논리값확인 및 고장효과전달을 효과적 으로 수행하기 위하여 경험적인 기법을 고안하여 적용하였다. 또한, 테스트 용이화 설계(design for testability)에 사용되는 기억소자(flip-flop)가 의사 입출력으로 이 용되어 VLSI 회로망의 시험성을 한층 높여 주었다. 그 결과, UATPG는 사용의 용이성과 성능면에서 좋은 성과를 보여주었다.

• 아동학회지
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• 제25권6호
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• pp.15-34
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• 2004

This study is an attempt to develop the 'Parental Intelligence Scale', which can be applied in the parent education and counselling and provide more useful information for more appropriate interventions by evaluating the characteristics of parent's roles and strong/weak points of the parent's roles under the special situation and environments. In developing the scales, this study reviews of numbers of existing literatures, analysis of scales and tools on parent's role or attitude, collection of episodes on parent's role, validity check processes by field experts, and 2 rounds of factor analysis. The outcomes of the study are as follows; In regard of the development of Parental Intelligence Scale, 3 factors of care-giving role, management role, nurturing role were derived from the conceptual and measurement model. From these 3 factors, 8 sub-factors of empathy, encourage, enhancement, rational authoritativeness, flexibility, rejection, acceptance, control were constructed. 39 question items were derived in order to measure these sub-factors. Especially through the two rounds of factor analysis, the question items with enhanced internal consistency were derived and total cumulative variance was increased, which made theoretical model into the generalized model possible.

• Macromolecular Research
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• 제12권3호
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• pp.251-257
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• 2004

The nature of the nematic liquid crystal (LC) alignment induced by the rubbed polyimide (PI) alignment layers (ALs) and the electro-optical (EO) properties of the LC cells are expected to depend on the chemical and physical features of the PI. By employing five pyromellitic dianhydride (PMDA)-type PIs having different functionalities, we have studied the effects of the PI's structure and chemistry on the alignment characteristics and the cell's EO properties. Increasing the flexibility of the PI increases the pretilt angle and tends to improve the alignment stability. On the other hand, the rigid, fluorinated PI displays poor stability for LCs and induces a less stable/uniform LC alignment and, subsequently, a small pre tilt angle. It also transpired that fluorination of the PI deteriorated the voltage-transmittance characteristics and the voltage holding ratio; increasing the flexibility of the PI structure improves these EO properties. The finding that the qualitative trends for the PI's functionalities are similar for both the alignment and EO properties suggests that the EO properties are closely related to the alignment characteristics, which are determined by short-range interactions between LC and PI molecules.

• Preventive Nutrition and Food Science
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• 제17권2호
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• pp.158-165
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• 2012

This study was designed to investigate whether the fatty acid composition could make a significant contribution to the oxidation stability of vegetable oils marketed in Korea. Ten kinds, 97 items of vegetable oils that were produced in either an industrialized or a traditional way were collected and analyzed for their fatty acid compositions and lipid oxidation products, in the absence or presence of oxidative stress. Peroxidability index (PI) calculations based on the fatty acid composition ranged from 7.10 to 111.87 with the lowest value found in olive oils and the highest in perilla oils. In the absence of induced oxidative stress, malondialdehyde (MDA), the secondary lipid oxidation product, was generated more in the oils with higher PI (r=0.890), while the tendency was not observed when the oils were subjected to an oxidation-accelerating system. In the presence of the oxidative stress, the perilla oils produced in an industrialized manner generated appreciably higher amounts of MDA than those produced in a traditional way, although both types of oils presented similar PIs. The results implicate that the fatty acid compositions could be a predictor for the oxidation stability of the vegetable oils at the early stage of oil oxidation, but not for those at a later stage of oxidation.

• Nuclear Engineering and Technology
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• 제49권6호
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• pp.1125-1134
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• 2017

In this paper, we present a new multilevel in space and energy diffusion (MSED) method for solving multigroup diffusion eigenvalue problems. The MSED method can be described as a PI scheme with three additional features: (1) a grey (one-group) diffusion equation used to efficiently converge the fission source and eigenvalue, (2) a space-dependent Wielandt shift technique used to reduce the number of PIs required, and (3) a multigrid-in-space linear solver for the linear solves required by each PI step. In MSED, the convergence of the solution of the multigroup diffusion eigenvalue problem is accelerated by performing work on lower-order equations with only one group and/or coarser spatial grids. Results from several Fourier analyses and a one-dimensional test code are provided to verify the efficiency of the MSED method and to justify the incorporation of the grey diffusion equation and the multigrid linear solver. These results highlight the potential efficiency of the MSED method as a solver for multidimensional multigroup diffusion eigenvalue problems, and they serve as a proof of principle for future work. Our ultimate goal is to implement the MSED method as an efficient solver for the two-dimensional/three-dimensional coarse mesh finite difference diffusion system in the Michigan parallel characteristics transport code. The work in this paper represents a necessary step towards that goal.

• 한국축산식품학회지
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• 제41권1호
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• pp.153-163
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• 2021

This study was conducted to examine the effects of starch noodles (dangmyeon; SNs) with different starch sources and porcine intestines (PIs) with different pH on the rehydration stability of Korean blood sausage (sundae). Mungbean SN3 and PI3 (pH 9.18) showed significantly higher values of 80.69%-91.67% and 79.66%-80.98%, respectively, regardless of the drying methods (hot air, vacuum and freeze drying) (p<0.05). A number of larger pores were observed only in the cross-section of the freeze dried SN and PI through SEM. SN2 (potato starch) and PI3 (pH 9.18) showed lower expansion (⁎ΔL 6.90 mm) and higher expansion ratio (⁎ΔL 26.29 mm), respectively, after rehydration of freeze dried sample (p<0.05). From the application of SN2 (potato starch) and PI (0.5%-2.0% Na-pyrophosphate) to freeze dried sundae manufacturing, higher rehydration stability of more than 91.5% was obtained. These results suggested that potato SN and treatment of PI with Na-pyrophosphate is useful for desirable rehydration stability of freeze dried sundae.

• Membrane and Water Treatment
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• 제13권5호
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• pp.245-257
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• 2022

Water quality characteristics and their spatial variations in the Nakdong River were statistically analyzed by multivariate techniques including correlation analysis, CA, and FA/PCA based on water quality parameters for 17 sites over 2017-2019, yielding PI values for primary factors. Site 10 indicated the highest parameter concentrations, and results of pearson's correlation analysis suggest that non-biodegradable organic matter had been distributed on the site. Five clusters were identified in order of descending pollution levels: I (Ib > Ia) > II (IIa > IIb) > III. Spatial variations started from sub-cluster Ib in which Daegu city and Geumho-river are joined. T-P, PO4-P, SS, COD, and TOC corresponded to VF 1 and 2, which were found to be principal components with strong influence on water quality. Sub-cluster Ib was strongly influenced by NO3-N and T-N compared to other clusters. According to the PIs, water quality pollution deteriorated due to non-biodegradable organic matter, nitrogen- and phosphorus-based nutrient salts in the middle and lower reaches, illustrating worsening water pollution due to inflows of anthropogenic sources on the Geumho-river, i.e., sewage and wastewater, discharged from Site 10, at which there is a concentration of urban, agricultural, and industrial areas.

• 한국가스학회지
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• 제7권3호
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• pp.24-31
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• 2003

화학공장은 수많은 장치들로 구성되어 있고 매우 복잡한 구조를 가지고 있다. 특히 분산 제어 시스템(Distributed Control System, DCS)이나 공정 정보 시스템(Process Information System, PIS) 등을 설치하여 매분 또는 매초 단위로 공정 데이터를 얻고 있다. 화학공장의 경우, 데이터들의 방대한 양 뿐 만 아니라 데이터들간의 상호 연관성이 크고 재순환이나 화학 반응 등으로 인하여 막대한 계산량 및 비선형성을 지니기 때문에 효과적 분석에 곤란한 점이 있다. 따라서 본 연구에서는 함수연결연상 신경망을 이용하여 입력변수들을 확장함으로써 신경망의 비선형성 표현능력과 학습능력이 뛰어난 프로그램의 개발에 주안점을 두고 있다. REFA (Real Time Fault Analyzer)는 실시간으로 공정정보를 입력받은 후 입력값을 PC로 매핑하고, 이를 다시 역으로 매핑하여 입력값을 예측하여 공정을 감시하는 시스템으로 개발되었으며, Tennessee Eastman 공정에 적용해 우수성을 입증하였다.

• 한국컴퓨터정보학회논문지
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• 제20권4호
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• pp.95-102
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• 2015

본 논문은 회로 최소화 문제를 간단하게 풀 수 있는 알고리즘을 제안하였다. 회로 최소화 문제는 수기식 방법인 카르노 맵과 전산화가 가능한 휴리스틱 방법인 Quine-McCluskey 알고리즘이 있다. 그러나 Quine-McCluskey 알고리즘은 변수 개수 n이 증가하면 $3^n/n$의 메모리와 수행횟수가 요구되는 단점을 갖고 있다. 제안된 방법은 빈도수에 기반하여 내포 항 표를 이용하여 주어진 부울 함수의 최소 항을 포함하는 주 내포 항을 빠르게 추출하는 방법을 적용하였다. 추출된 주 내포 항들 중에서 중복 선택된 여분의 주 내포 항을 빈도수를 적용하여 제거하는 방법을 제안하였다. 제안된 알고리즘은 비록 변수 개수 n이 증가하여도 다항시간으로 회로를 최소화시킬 수 있는 해를 구할수 있는 장점을 갖고 있다. 제안된 알고리즘을 3-변수와 4-변수의 다양한 사례들에 적용한 결과 해를 빠르고 정확하게 구할 수 있었다.