• 대한수학회보
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• 제57권3호
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• pp.535-545
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• 2020

Let A be an m × n matrix over nonnegative integers. The isolation number of A is the maximum number of isolated entries in A. We investigate linear operators that preserve the isolation number of matrices over nonnegative integers. We obtain that T is a linear operator that strongly preserve isolation number k for 1 ≤ k ≤ min{m, n} if and only if T is a (P, Q)-operator, that is, for fixed permutation matrices P and Q, T(A) = P AQ or, m = n and T(A) = P A^tQ for any m × n matrix A, where A^t is the transpose of A.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2576-2581
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• 2003

We consider fault detection and isolation (FDI) problem for inertial navigation systems (INS) which use redundant inertial sensors and propose an FDI method using average of multiple parity vectors which reduce false alarm and wrong isolation, and improve correct isolation. We suggest optimal isolation threshold based on navigation performance, and suggest optimal sample number to obtain short detection time and to enhance detectability of faults little larger than threshold.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2188-2191
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• 2005

We consider a fault detection and isolation problem for inertial navigation systems which use redundant inertial sensors. We propose a FDI method using average of multiple parity vectors which reduce false alarm and wrong isolation, and improve correct isolation. We suggest the number of redundant sensors required to isolate simultaneous faults. The performance of the proposed FDI algorithm is analyzed by Monte-Carlo simulation.

• 제어로봇시스템학회논문지
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• 제4권6호
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• pp.695-702
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• 1998

In this paper, we propose a novel fault isolation filter design method using the left eigenstructure assignment scheme proposed by Choi et. al., The proposed filter shows good fault isolation performance with exact eigenstructure assignment. An eigenstructure assignment methodology which satisfies the required fault isolation conditions is also proposed. The proposed method guarantees that the corrupted m simultaneous faults can be isolated when the number of available output measurements are (m+1).

• 대한임상검사과학회지
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• 제39권2호
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• pp.76-85
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• 2007

The total number of clinical materials collected from Dec 1, 2005 to Nov 30, 2006 in C. hospital was 63,133. Among these materials, the isolation of Staphylococcus spp. was 5,252 strains. The proportions of Staphylococcus species infection were as follows ; 46.7% in S. aureus, 39.3% in S. epidermidis, 4.7% in S. hominis, 3.8% in S. haemolyticus, 2.9% in S. capitis and 2.5% in others. Seventeen strains of Staphylococcus species were identified with an isolation range of 0.02-46.7%. The isolation ratios of Staphylococcus species were 7.8% (2,134/27,362) in female, 8.7% (3,118/35,807) in male and 8.3% (5,252/63,133) in both. The age-related frequencies of Staphylococcus species were 22.1% in the 60-69 year group, 19.3% in the 70-79 year group and 17.1% in the 50-59 year group. The isolation ratio of the 0-49 year group to the 50-over 80 year group were 1.74 times in female, 1.92 in male and 1.85 in both. The isolation frequency of Staphylococcus spp. was at its highest in April (9.9%) and at its lowest in February (6.8%) according to monthly analysis. According to seasonal variation, the isolation frequencies of Staphylococcus spp. were 27.0% in Summer, 25.9% in Spring, 23.9% in Fall and 23.2% in Winter. The clinical departments showing over 9% isolation rate against Staphylococcus spp. were critical care medicine (12.9%), department of pediatrics (11.6%), department of urology (9.8%) and department of neuro-surgery (9.1%). On the other hand, the lowest number was observed in the department of family medicine. The clinical material showing over 15% isolation rate against Staphylococcus spp. were 32.1% in urine (random urine and catheterized urine), 20.6% in blood and 16.0% in sputum.

• 전산구조공학
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• 제3권1호
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• pp.71-81
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• 1990

Base isolation system은 구조물의 기초하부에 설치되며 지진에 의한 구조물의 피해를 감소시켜 준다. 지금까지 많은 공학들에 의해 여러가지 base isolation system이 개발되었으나 실용화된 것은 1970년대에 laminated rubber bearing(LR type)이 개발되고서부터 였다. 최근에는 laminated rubber bearing밑에 미끄럼판을 둔 새로운 base isolation system(SR type)이 개발되었다. 본 연구에서는 isolation system과 구조물의 여러가지 성질에 따른 isolation효과에 대한 연구를 수행하였다. 이 연구의 결과, isolaion system은 지진하중이 작용할 때 건물에 발생하는 피해를 상당히 감소시킴을 알 수 있으며, isolaion system의 주기가 길어짐에 따라 isolation효과는 증가함을 알 수 있다. 그리고 건물의 높이가 증가함에 따라 isolation효과는 줄어든다는 것을 알 수 있다. SR type isolation system이 있는 건물에 지진하중이 작용할 때, 건물내부에서 발생하는 가속도와 층간변위, 그리고 전체변위는 LR type의 경우보다 작으므로 보다 효율적이라는 것을 알 수 있다.

• Journal of Microbiology and Biotechnology
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• 제33권8호
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• pp.1066-1075
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• 2023

Kimchi is a traditional Korean fermented vegetable that is stored and fermented at low temperatures. However, kimchi lactic acid bacteria (LAB) are typically isolated under mesophilic conditions, which may be inappropriate for isolating the diverse LAB. Therefore, this study investigated the suitable conditions for isolating various LAB from kimchi. Here, LAB were isolated from four kimchi samples using MRS, PES, and LBS media and varying isolation temperatures (30, 20, 10, and 5℃). Then, MRS was selected as the suitable medium for LAB isolation. A comparison of culture-dependent and culture-independent approaches indicated that 5℃ was not a suitable isolation temperature. Thus, the number and diversity of LAB were determined at 30, 20, and 10℃ using 12 additional kimchi samples to elucidate the effect of isolation temperature. With the exception of two samples, most samples did not substantially differ in LAB number. However, Leuconostoc gelidum, Leuconostoc gasicomitatum, Leuconostoc inhae, Dellaglioa algida, Companilactobacillus kimchiensis, Leuconostoc miyukkimchii, Leuconostoc holzapfelii, and Leuconostoc carnosum were isolated only at 10 and 20℃. The growth curves of these isolates, except Leu. holzapfelii and Leu. carnosum, showed poor growth at 30℃. This confirmed their psychrotrophic characteristics. In Weissella koreensis, which was isolated at all isolation temperatures, there was a difference in the fatty acid composition of membranes between strains that could grow well at 30℃ and those that could not. These findings can contribute to the isolation of more diverse psychrotrophic strains that were not well isolated under mesophilic temperatures.

• 대한간호학회지
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• 제38권5호
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• pp.712-719
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• 2008

Purpose: The purpose of this study was to investigate the factors associated with social isolation in older adults using a senior welfare center. Methods: This study was a cross-sectional survey. Data was collected from June to August 2006 using a questionnaire. A total of 248 older adults responded. Results: About one third (34.9%) of participants responded they felt socially isolated. There were statistically significant differences in living, religion, family and belongingness social support, loneliness, depression, family function, perceived health status, and number of chronic illnesses between socially isolated and non isolated groups. However, factors influencing social isolation were family function (OR=0.954, CI=0.926-0.982), loneliness (OR=1.042, CI=1.002-1.083), depression (OR=1.041, CI=1.002-1.081), and number of chronic illness (OR=1.657, CI=1.153-2.382). Conclusion: We found that some older adults were feeling socially isolated even though the senior welfare center was a good place to meet people. The findings of this study indicated that older adults suffering from social isolation need special attention and may benefit from interventions which promote health and social interactions. Further studies are needed to develop and evaluate an intervention program for this population.

• Journal of Ecology and Environment
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• 제31권4호
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• pp.255-260
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• 2008

A commonly held view in studies of character displacement is that character states of both species are shifted in areas of sympatry. This view has been confirmed in an overwhelming number of cases for ecological character displacement. Excluding species pairs in which one of the two interacting species is found only within the distribution of the other species and species displaying gynogenesis, the pattern of reproductive character displacement is asymmetrical in that the shift in character states between areas of symaptry and allopatry occurs in only one of the two interacting species. Hypotheses for the reasons behind this asymmetry in reproductive character displacement include (1) homogenization by gene flow, (2) other mechanisms of reproductive isolation, and (3) sufficient reproductive isolation being provided by one of the interacting species exhibiting a pattern of reproductive character displacement. Because reproductive isolation can be achieved by divergence at any point in a sequence of premating reproductive behaviors and postmating developments, it is necessary to understand the mechanisms of reproductive isolation of two interacting taxa in areas of sympatry and allopatry and to analyze the relative contributions of potential factors to reproductive isolation to disentangle hypotheses for the patterns of asymmetry.

• 디지털융복합연구
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• 제16권7호
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• pp.429-439
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• 2018

본 연구는 사회적 고립 수준에 따라 인지기능에 차이가 있는지, 그리고 사회적 고립을 구성하는 개별 항목이 인지기능 수준과 관련성이 있는지 분석하는 것이 목적이다. 본 연구는 사회적 고립을 배우자 혹은 자녀가 없는 구조적 고립상태와 가족, 친구, 공식적 사회단체 등과 접촉하지 않는 접촉 고립상태로 구분하였다 본 연구는 한국고령화연구패널 5차 자료 중 65세 이상 노인 3,971명을 대상으로 다변수 회귀분석을 실시하였다. 분석 결과에 의하면 사회적으로 고립되어 있을수록 인지기능 수준이 낮다는 점을 확인하였다. 사회적 고립의 여러 구성 요소 중 친구 이웃 고립, 사회활동 고립이 인지기능과 관련성이 있다는 점도 확인하였다. 노인의 인지기능 약화를 방지하기 위해 다양한 사회활동 참여를 위한 정책이 필요한 것으로 판단된다. 사회적 고립의 영향을 고려할 때 향후 사회적 고립에 영향을 주는 요인을 분석하는 것도 필요하다.