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        검색결과 1,131

        201.
        2021.05 구독 인증기관·개인회원 무료
        This study pursues to solve a batch of nonlinear parameter estimation (NPE) problems where a model interpreting the independent and the dependent variables is given and fixed but corresponding data sets vary. Specifically, we assume that the model does not have an explicit form and the discrepancy between a value from a data set and a corresponding value from the model is unknown. Due to the complexity of the problem, one may prefer to use heuristic algorithms rather than gradient-based algorithms, but the performance of the heuristic algorithms depends on their initial settings. In this study, we suggest two schemes to improve the performance of heuristic algorithms to solve the target problem. Most of all, we apply a Bayesian optimization to find the best parameters of the heuristic algorithm for solving the first NPE problem of the batch and apply the parameters of the heuristic algorithm for solving other NPE problems. Besides, we save a list of simulation outputs obtained from the Bayesian optimization and then use the list to construct the initial population set of the heuristic algorithm. The suggested schemes were tested in two simulation studies and were applied to a real example of measuring the critical dimensions of a 2-dimensional high-aspect-ratio structure of a wafer in semiconductor manufacturing.
        211.
        2021.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Resistance to extended-spectrum cephalosporin in Enterobacteriaceae is increasingly prevalent in South Korea. This study aims to explore the distribution of AmpC genes in Proteus mirabilis isolated from stray and hospital-admitted companion animals in South Korea. AmpC β-lactamases hold clinical significance due to its potential to facilitate antimicrobial resistance to cefoxitin, cefazolin, and most penicillins. A total of 163 bacterial isolates belonging to the Enterobacteriaceae family were collected from dogs (n = 158) and cats (n=5). Of them, 134 isolates were from hospital-admitted animals, while 29 isolates from stray animals. Boronic acid tests and antimicrobial susceptibility tests were conducted for an initial screening to detect AmpC β-lactamase resistant P. mirabilis. Gene-specific PCRs were conducted to identify the type of AmpC genes, which include six groups (MOXM, CITM, DHAM, ACCM, EBCM, and FOXM), in the resistant isolates. The boronic acid disk tests revealed 45 (27.6%) positive isolates out of 163 isolates tested. Of these 45 isolates, six were determined to harbor the EBCM gene, 13 for CITM, one for FOXM, and one for DHAM by single detection PCR. No isolates carried for ACCM or MOXM. Thus, a total of 21 out of 163 isolates (12.9%) were demonstrated to possess AmpC genes. No isolates contain more than one group of AmpC gene family. A significantly higher percentage of P. mirabilis was found to possess AmpC genes compared to past studies. Therefore, the increasing trend in antimicrobial resistance in P. mirabilis indicates a dire need to monitor antimicrobial prescription in the veterinary field.
        4,000원
        212.
        2021.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Nuclear power plants (NPPs) produce radioactive waste and decommissioning this waste entails additional cost; determining these costs for various types and specifications of radioactive waste can be challenging. The purpose of this study is to identify major determinants of the decommissioning cost and their impact on NPPs. To this end, data from defunct NPPs were gathered and 2SLS (Two Stage Least Squares) regression models were developed to investigate the major contributors depending on the reactor types, viz. PWR (Pressurized Water Reactors) and BWR (Boiling Water Reactors). Additionally, cost estimations and the Monte Carlo simulation were performed as part of performance validation. Our study established that the decommissioning costs are primarily influenced by the level of radioactivity in the decommissioned waste, which can be realized from operational factors like operation period, overall efficiency, and plant capacity, as well as from duration of decommissioning and labour cost. While our study provides an improved statistical approach to recognize these factors, we acknowledge that our models have limitations in forecasting accurately which we envisage to bolster in future studies by identifying more substantive factors.
        6,300원
        213.
        2021.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Using data from flies collected with pitfall traps in 365 forests on a nationwide scale in Korea, the abundance and distribution changes of two families (Phoridae and Lauxaniidae) in Korean forests were predicted at the genus level according to two climate change scenarios: RCP 4.5 and RCP 8.5. The most suitable temperature for the 17 major genera was estimated using a weighted average regression model. Stichillus and Anevrina displayed the lowest optimum temperature with 7.6℃ and 8.5℃ in annual mean temperature, respectively, whereas Chonocephalus had the highest optimum temperature with 12.1℃. Among thirty genera, seven genera (four from Phoridae and three from Lauxaniidae), which showed their abundance in a bell-type or linear pattern along the temperature gradient, were used for predicting the distribution changes according to the future climate change scenarios. All the taxa of this study are expected to decrease in abundance and distribution as a function of temperature increase. Moreover, cold-adapted taxa were found to be more affected than warmadapted taxa.
        4,000원
        214.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aims of the present study were to confirm that regulation of the PA and environment via TGF-β regulation of sperm by Percoll-separated in porcine uterine epithelial cells. And, it was performed to identify the cytokines (TGF-β1, 2 and 3, TGF-β receptor1 and 2; interleukin, IL-6, IL-8) and PA-related genes (urokinase-PA, uPA; tissue- PA, tPA; PA inhibitor, PAI; uPA-receptor, uPAR) by spermatozoa. The experiment used porcine uterus epithelial cells (pUECs) and uterine tissue epithelial cells, Boar sperm were separated by discontinuous Percoll density gradient (45/90%), and tissues were co-incubated with spermatozoa, followed by real-time PCR. PA activity was measured of sperm by discontinuous Percoll density gradient (45/90%) for 24 hours. To measure viability and acrosome damage of sperm double stained propidium iodide (PI) and SYBR- 14 or FITC-PNA were used. In results, binding ratio of Percoll-separated sperm was found no differences, but sperms isolated from 90% Percoll layer reduced PA activity (p < 0.05). when co-cultured sperm selected Percoll in porcine uterus tissues epithelial cells, 90% layer sperm increased TGF-β R1, contrastively tPA and PAI-1 in comparison with control (p < 0.05). 45% sperm was decreased the expression of uPA (p < 0.05). TGF-β decreased PA activity in the supernatant collected from pUECs (p < 0.05). Especially, The group including uPA, PAI-1 were induce sperm intact, while it was reduced in sperm damage when compared to control (p < 0.05). Also, there was no significant difference group of tPA and tPA+I in the dead sperm and acrosome damage compared to control. The expression of tPA and PAI showed a common response. Percoll-separated spermatozoa in 90% layer reduced tPA and IL-related gene mRNA expression. Thus, Percoll-sparated sperm in 90% layer show that it can suppress inflammation through increased expression of TGF-β and downregulation of PA and IL in epithelial cells compared to 45% layer Percoll.
        4,000원
        215.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cymbidium ‘Aroma Pink’는 국립원예특작과학원에서 2017년 도에 육성한 신품종으로, 2000년에 C. Lucky Rainbow ‘Lapin Hot’과 C. eburneum을 인공교배하여 개발된 품종이다. 교배 후 기내파종과 하우스 순화를 통해 120개의 실생묘를 얻었고, 그 중 화색, 엽형, 꽃대 및 생육특성 등을 고려하여 3계통을 1차 선발하였고, 2011년부터 2016년까지 특성 검정을 통하여 품종의 안정성과 균일성을 확인하였다. 그 결과, 최종적으로 ‘00-1174-100’한 계통을 선발하였고 ‘원교 F1-62’로 계통명을 부 여한 후, ‘Aroma Pink’로 명명하였다. ‘Aroma Pink’ 품종은 백 색 바탕에 꽃받침 일부가 연한 분홍색, 순판 가운데가 노란색 을 띄며 화형은 꽃잎과 꽃받침이 약간 안쪽으로 오므라드는 안 아피기 형태이며 꽃의 길이와 폭은 6.1cm, 5.2cm로 작은 편이다. 전체적으로 동그란 화형과 중형종 크기는 모본인 C. Lucky Rainbow ‘Lapin Hot’과 유사하나 진한 적색 순판 대신 부본의 노란색 순판과 화색을 닮아 강렬한 느낌보다는 전체적으로 화 사한 느낌을 준다. 꽃대는 평균 2.9개 발생하고 화서당 꽃 수 가 6.5개로 적은 편에 속하지만, 부본인 C. eburneum 원종의 향기를 가지고 있다. 또한 직립한 꽃대에 늘어짐이 적은 잎을 가져 전체적으로 안정적인 형태를 이루며 개화시기는 3월경으 로 만생종에 속한다. 한편 고온에 의해 화색이 탁해질 수 있 으나, 전반적으로 재배 관리가 용이한 편이다.
        4,000원
        216.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문은 고령운전자의 운전 면허증 자진 반납을 유도하기 위하여 운전 시뮬레이터를 활용한 안전 운전 수행능력 평가 콘텐츠를 제안하고자 한다. 사용빈도가 많은 학술 데이터베이스에서 운전 시뮬레이터를 사용한 고령운전자 대상의 운전 능력을 평가하는 관련 문헌들을 검색한 후, 텍스트 네트워크를 사용하여 주행에 관련된 키워드들 간 연결중심성, 근접중심성, 매개중심성을 분석하였다. 이에 대한 결과로 도로유형 별 주행에서는 2차선과 4차선의 고속도로에서 연결중심성, 고속도로와 교차로에서는 매개중심성이 높게 나타났다. 그리고 주행상황 별 평가내용 키워드 분석 결과 에서는 연결중심성이 ‘좌회전’, ‘무단횡단’, ‘정체된 차량 회피’ 등에서 높게 나타났으며, 매개중심성에 서는 ‘좌회전’이 가장 많이 사용되는 평가내용으로 나타났다. 하지만 도로유형별 주행상황과 이에 대한 평가내용에 대한 근접중심성이 매우 유사하게 나타난 것은 각각의 실험 설계가 서로 비슷하다는 것을 의미한다.
        4,900원