• 대한화학회지
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• 제47권4호
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• pp.325-333
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• 2003

1,2-와 1,3-dioxetane$(C_2O_2H_4)$, 그리고 1,3-cyclodisiloxane$(Si_2O_2H_4)$에 대하여 높은 이론 수준에서 분자구조, 진동주파수, 그리고 에너지 등을 계산하였다. 위의 모든 분자들에 대하여 TZ2P CCSD(T)의 이론 수준까지 분자구조를 최적화 하였으며. 진동주파수는 여러 basis set에서 SCF 방법으로 계산하였다. 본 연구에서 최적화된 분자구조들에 대한 진동주파수가 모두 실수(real number)로 예측됨으로서, 제안된 모든 분자구조가 local minimum 구조임을 확인하였다. 1,2- 및 1,3-dioxetane들과 cyclodisiloxane이 두 분자의 aldehyde와 silanone으로 해리 될 때의 중합에너지를 zero-point vibrational energy(ZPVE)를 고려하여 계산하고, 안정성을 비교하였다.

• Journal of Mechanical Science and Technology
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• 제15권3호
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• pp.291-299
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• 2001

Recently, severe wear on the shutdown rod cladding of Ulchin Nuclear Power Plant #1, #2 were observed by the Eddy Current Test(E.C.T.). In particular, the wear at the sixth card location was up to 75%. The test results indicated that the Flow Induced Vibration(F.I.V.) might be the cause of the fretting wear resulting from the contact between Rod Cluster Control Assemblies(RCCAs) and their spacing cards(guide plates) arranged in the guide tube. From reviewing RCCAs fretting wear repots and analyzing the general characteristics of F.I.V. mechanism in the reactor, geometric layout and flow conditions around the control rod, it is concluded that the turbulence excitation is the most probable vibration mechanism of RCCA. To identify the governing mechanism of RCCA vibration, an experiment was performed for a representative rod position in which the most serious fretting wear experienced among the six rod positions. The experimental rig was designed and set up to satisfy the governing nondimensional numbers which are Reynolds number and mass damping parameter. The vibration amplitude measurement by the non-contact laser displacement sensor showed good agreements in the frequency and the maximum wearing(vibration) location with Ulchin E.C.T. results and Framatome report, respectively. The sudden increase in the vibration amplitude was sensed around the 6th guide plate with mass flow rate variation. Comparing the similitude rod behaviour with the idealized response of a cylinder in flow induced vibration, it was found that he dominant mechanism of vibration was transferred from turbulence excitation to periodic shedding at the mass flow ate 90ι/min. Also the critical velocity of the vibration in RCCAs was determined and the vibration can be prevented by reducing the bypass flow rate below the critical velocity.

• 한국컴퓨터정보학회논문지
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• 제28권5호
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• pp.129-153
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• 2023

본 연구는 코로나19 팬데믹 상황이 심각하였을 때, 대중들의 관심도가 높은 코로나19 백신과 관련한 대량의 언론 보도 프레임을 분석하여, 위기커뮤니케이션의 핵심 요소로서 바람직한 언론의 역할과 방향성을 모색하기 위해 수행되었다. 본 연구의 기간은 코로나19 백신 개발이 가시화되기 시작한 2020년 11월부터 2021년 6월까지 8개월이며, 연구 대상은 대중 신뢰도 및 이용도 순위에 따라 조선일보, 중앙일보, 동아일보, 한겨레로 설정하였다. 결과의 정확성 및 효율성을 제고하기 위해 최신 빅데이터 연구 기법인 구조적 토픽 모델링(STM) 및 의미연결망 분석 기법을 활용하였다. 연구결과, 구성 단어들의 명확한 군집도 및 중심성 분석값을 기반으로 각 언론사 당 16개 프레임, 총 64개의 유의미한 프레임이 도출되었다. 또한 프레임의 구성 정도 및 내용에 대한 차이를 확인하기 위해 4개 언론사를 비교 분석하였으며, 모든 언론사마다 유의미한 차이가 없음을 확인하였다.

• 융합보안논문지
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• 제16권1호
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• pp.49-58
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• 2016

이 연구는 민간경비원의 조직학습화수준에 따른 조직몰입이 직무만족에 미치는 영향을 검증하고자 수도권에 분포되어 있는 8개의 업체에 직접 방문하여 유층집락무선표집법을 통하여 2009년 9월 1일 부터 10월 10일 까지 총 40일간에 걸쳐 실시하였다. 설문지는 총 320부를 배포하여 회수된 259부의 설문지를 분석에 활용하였다. 수집된 설문지는 SPSS 21.0, AMOS 21.0프로그램을 활용하여 분석하였으며, 통계분석 기법은 신뢰도분석, 요인분석, 상관분석, 일원변량분석, 사후비교분석, 다중회귀분석 및 경로분석 등이 사용되었다. 통계적 유의 수준은 .05로 설정하였다. 이와 같은 방법과 절차에 따른 자료 분석을 통하여 본 연구에서 얻은 결과는 다음과 같다. 조직학습화수준에서 인간차원, 업무차원만이 조직몰입에 유의한 영향을 미친다. 그리고 조직몰입은 직무만족에 유의한 영향을 미친다.

• 한국환경과학회지
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• 제18권2호
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• pp.129-139
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• 2009

Development of an artificial neural network model was presented to predict the daily maximum $SO_2$ concentration in the urban-industrial area of Ulsan. The network model was trained during April through September for 2000-2005 using $SO_2$ potential parameters estimated from meteorological and air quality data which are closely related to daily maximum $SO_2$ concentrations. Meteorological data were obtained from regional modeling results, upper air soundings and surface field measurements and were then used to create the $SO_2$ potential parameters such as synoptic conditions, mixing heights, atmospheric stabilities, and surface conditions. In particular, two-stage clustering techniques were used to identify potential index representing major synoptic conditions associated with high $SO_2$ concentration. Two neural network models were developed and tested in different conditions for prediction: the first model was set up to predict daily maximum $SO_2$ at 5 PM on the previous day, and the second was 10 AM for a given forecast day using an additional potential factors related with urban emissions in the early morning. The results showed that the developed models can predict the daily maximum $SO_2$ concentrations with good simulation accuracy of 87% and 96% for the first and second model. respectively, but the limitation of predictive capability was found at a higher or lower concentrations. The increased accuracy for the second model demonstrates that improvements can be made by utilizing more recent air quality data for initialization of the model.

• 보건행정학회지
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• 제20권2호
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• pp.40-52
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• 2010

Health insurance fees are set by relative value scales and conversion factors. Since 2008 the conversion factor has been classified into 7 according to the provider type, and a separate contract has been made respectively. As such classification of the conversion factor reflects only the different characteristics of providers, however, further classification to reflect the different cost structures of providers is proposed. Cost varies according to the type of not only providers but also services each provider supply. In fact different cost structures of providers are the result of their different services. This study analyzed the cost structure of medical services to propose a new approach to the classification of the conversion factor. This study analyzed the cost structure of medical services using cost data constructed in the revision study of relative value scales. The cost data consist of doctor's fee, support staff's fee, cost of medical equipments, cost of medical supplies and indirect cost. The proportion of each cost component to the total cost was analyzed in terms of service department and service type. 72 service groups are defined in terms of the combination of service department and service type. Through cluster analysis, 72 service groups were reduced into 7 clusters each of which has a similar cost structure. Conversion factor is contracted annually to reflect the change in the cost of providing medical services. So the classification of conversion factor has to be based on the cost structures of medical services, not the characteristics of providers. Service clusters derived in this study can be used as a new classification for health insurance fee contract.

• The Plant Pathology Journal
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• 제29권2호
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• pp.209-220
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• 2013

Root colonization by Pseudomonas chlororaphis O6 induces systemic drought tolerance in Arabidopsis thaliana. Microarray analysis was performed using the 22,800-gene Affymetrix GeneChips to identify differentially-expressed genes from plants colonized with or without P. chlororaphis O6 under drought stressed conditions or normal growth conditions. Root colonization in plants grown under regular irrigation condition increased transcript accumulation from genes associated with defense, response to reactive oxygen species, and auxin- and jasmonic acid-responsive genes, but decreased transcription factors associated with ethylene and abscisic acid signaling. The cluster of genes involved in plant disease resistance were up-regulated, but the set of drought signaling response genes were down-regulated in the P. chlororaphis O6-colonized under drought stress plants compared to those of the drought stressed plants without bacterial treatment. Transcripts of the jasmonic acid-marker genes, VSP1 and pdf-1.2, the salicylic acid regulated gene, PR-1, and the ethylene-response gene, HEL, also were up-regulated in plants colonized by P. chlororaphis O6, but differed in their responsiveness to drought stress. These data show how gene expression in plants lacking adequate water can be remarkably influenced by microbial colonization leading to plant protection, and the activation of the plant defense signal pathway induced by root colonization of P. chlororaphis O6 might be a key element for induced systemic tolerance by microbes.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2020년도 춘계학술대회
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• pp.47-47
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• 2020

The Korean National Agrobiodiversity Center holds the more than 1300 accessions of proso millet, but a large portion of accessions are landrace of Korea that has very similar traits. To comprehend the maximum genetic diversity of this crop, a core collection with minimum number of accessions will facilitate easy access to genetic material. Here we assessed the genetic diversity and population structure in a germplasm collection of 830 accessions by employing EST-SSR markers and morphological traits. A total of 107 alleles were detected with an average allele number of 4.9 per locus among the 830 accessions based on 37 EST-SSR markers. The number of alleles per locus ranged from 2 to 7. Polymorphism information content and expected heterozygosity ranged from 0.06 to 0.68 (mean = 0.21) and 0.06 to 0.73 (mean = 0.23), respectively. The germplasm collection was separated into two groups based on population structure analysis, whereas principal coordinate analysis (PCoA) could not cluster accessions according to their geographic origin. Subsequently, a preliminarily developed core collection with a total of 141 accessions (17%) was selected from the whole set of germplasm by combining allelic variations of EST-SSR markers and eight different phenotypic traits. The core collection optimally represented the whole germplasm collection and displayed a similar level of PCoA value and genetic variation from the initial collection. The results obtained here provide a primary resource for further genetic analysis and establish a reference for further development of appropriate genetic breeding strategies.

• 한국어류학회지
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• 제2권1호
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• pp.36-46
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• 1990

제주도 남부 화순연안 정치망에서 채집된 유영생울의 군집구조을 밝히기 위하여 1987년 3월~10월까지 매월 1회씩 채집하였다. 조사시의 표층수온($13.3{\sim}24.8^{\circ}C$)과 염분($32.20{\sim}34.96^{\circ}/_{\circ\circ}$)은 계절적 변화를 보였고, 특히 여릅철에 변동폭이 컸다. 조사기간동안 21과(科) 28속(屬) 3종((種)이 채집되었고 20cm이하(96%)와 30g이하(74%)의 생물이 대부분이었다. 출현개체 수와 채집생물 량은 계절에 따라 다르나 1~2 종의 생울에 의해 우점(50%이상)되고 있으며 주요생물로는 전갱이, 줄도화돔, 오징어, 고등어류등이었다. 봄철에 생물량은 많지 않으냐나 종류수, 다양도 및 개체수 당 정보량지수가 높았고, 8월에 는 출현 종 수는 많지 않으나 다양도 및 개체수 당 정보량지수가 비교적 높게 나타났다. 2회이상 출현한 24종(種)은 모두 유사값도 0.14에서 군(群)을 이루었고, 비교적 높은 유사값 0.50을 기준으로 했을때 4개의 군(群)으로 구분되었다.

• 한국통신학회논문지
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• 제36권11A호
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• pp.903-911
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• 2011

이 논문에서는 무선 센서네트워크의 한정된 에너지 사용의 문제점을 해결하기 위해 노드 적응적 데이터 병합 및 전달 기법을 제안한다. 기존 무선 센서네트워크 환경에서 에너지 효율을 위해 사용되었던 계층적 구조 방식의 LEACH나 TEEN 방식을 기반으로 제안된 방법은 모든 라운드에서 전송 데이터가 있는 멤버노드(Member Node:MN)이나 전송 데이터가 없는 MN 모두에게 프레임을 할당하여 전송데이터가 없는 MN도 활성상태 모드(Active Mode)로 에너지를 소비한다. 또한 수집 데이터가 있다해도 이전 전송 데이터와 동일한 경우에도 데이터를 전송함으로 MN의 에너지 소비를 가중시킨다. 대부분의 계층적 방식은 LEACH를 기반으로 제안되었다. 따라서 이 논문에서는 이런 문제를 해결하기 위해 센싱 데이터가 있는 MN에게만 프레임을 할당한다. 또한 센싱 데이터가 있는 MN 중 이전 전송 데이터와 통일한 데이터를 센싱한 MN는 휴지상태 모드(Sleep Mode)로 전환하여 중복 데이터 전송을 피해 클러스터헤드(Cluster Head:CH)의 데이터전송 에너지를 감소하고 CH에서 데이터 병합 에너지를 감소하여 네트워크 전체 에너지 효율성을 제공한다.