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        검색결과 180

        2.
        2023.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In Korea, most nuclear power plants were designed based on the design response spectrum of Regulatory Guide 1.60 of the NRC. However, in the case of earthquakes occurring in the country, the characteristics of seismic motions in Korea and the design response spectrum differed. The seismic motion in Korea had a higher spectral acceleration in the high-frequency range compared to the design response spectrum. The seismic capacity may be reduced when evaluating the seismic performance of the equipment with high-frequency earthquakes compared with what is evaluated by the design response spectrum for the equipment with a high natural frequency. Therefore, EPRI proposed the inelastic energy absorption factor for the equipment anchorage. In this study, the seismic performance of welding anchorage was evaluated by considering domestic seismic characteristics and EPRI's inelastic energy absorption factor. In order to reflect the characteristics of domestic earthquakes, the uniform hazard response spectrum (UHRS) of Uljin was used. Moreover, the seismic performance of the equipment was evaluated with a design response spectrum of R.G.1.60 and a uniform hazard response spectrum (UHRS) as seismic inputs. As a result, it was confirmed that the seismic performance of the weld anchorage could be increased when the inelastic energy absorption factor is used. Also, a comparative analysis was performed on the seismic capacity of the anchorage of equipment by the welding and the extended bolt.
        4,000원
        3.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The cellular communication network factor (CCN) family proteins regulate many biological events such as angiogenesis, tumor growth, placentation, implantation, and embryogenesis. The expression and function of CCN1, CCN2, and CCN3 at the maternal-conceptus interface are established in humans and rodents, but little is known about the role of CCN4 to CCN6 in the reproductive organs in any other species. Several studies in transcriptome analysis in pigs have shown that the expression of CCN4 and CCN6 increases in the endometrium during early pregnancy. However, their expression, regulation, and function in the endometrium throughout the estrous cycle and pregnancy have not been fully understood in pigs. Thus, we determined the expression, localization, and regulation of CCN4 and CCN6 during the estrous cycle and at the maternal-conceptus interface in pigs. We found that the levels of CCN4, but not CCN6, changed during the estrous cycle. The levels of CCN4 were greater during mid- to late pregnancy than in the early stage, and the levels of CCN6 were greatest on Day 15 of pregnancy. CCN4 and CCN6 were detected in conceptus tissues during early pregnancy and in chorioallantoic tissues during the later stage of pregnancy. CCN4 mRNA was mainly localized to epithelial cells, CCN6 mRNAs to epithelial and stromal cells in the endometrium. In endometrial explant cultures, CCN4 expression was increased by progesterone, and CCN6 expression by interferon-γ. These results suggest that CCN4 and CCN6 may play roles in the establishment and maintenance of pregnancy by regulating the endometrial epithelial cell functions in pigs.
        4,200원
        4.
        2022.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Periodontal disease is a chronic but treatable condition which often does not cause pain during the initial stages of the illness. Lack of awareness of symptoms can delay initiation of treatment and worsen health. The aim of this study was to develop and compare different risk prediction models for periodontal disease using machine learning algorithms. We obtained information on risk factors for periodontal disease from the Korea National Health and Nutrition Examination Survey (KNHANES) dataset. Principal component analysis and an auto-encoder were used to extract data on risk factors for periodontal disease. A synthetic minority oversampling technique algorithm was used to solve the problem of data imbalance. We used a combination of logistic regression analysis, support vector machine (SVM) learning, random forest, and AdaBoost to classify and compare risk prediction models for periodontal disease. In cases where we used principal component analysis (PCA) to extract risk factors, the recall was higher than the feature selection method in the logistic regression and support-vector machine learning models. AdaBoost’s recall was 0.98, showing the highest performance of both feature selection and PCA. The F1 score showed relatively high performance in Ada- Boost, logistic regression, and SVM learning models. By using the risk factors extracted from the research results and the predictive model based on machine learning, it will be able to help in the prevention and diagnosis of periodontal disease, and it will be used to study the relationship with various diseases related to periodontal disease.
        4,300원
        5.
        2022.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper aims to propose a new systematic approach to analyze the factor productivity and to investigate those characteristics of factor productivity in operational and managerial perspectives. The Cobb-Douglas production function is adopted to estimate the labor and capital productivity. In estimating those productivities the data of The Research on the Actual Condition of Coastal Fisheries (RACF), especially those of Jeon-Nam Province are used. The statistical analysis of RACF data shows that the characteristics are a little bit different between labor and capital of the operational equipment in the coastal fisheries. The Cobb-Douglas type production function is useful in estimating the factor productivity, especially in case of ‘coastal Stow-net fishery’ even though the limited data is used. However, in case of ‘trap fishery,’ the Cobb-Douglas production function appears to have some limitations in estimation. This implies that estimating the factor productivities in fisheries employing broad perspectives and various methods are needed.
        4,900원
        6.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Developed countries that have experienced decline in productivity due to the economic crisis in the past have come to recognize the smart factory as an important means to strengthen the competitiveness of the manufacturing industry due to the increase in labor costs, the avoidance of the manufacturing industry, and the resolution of the shortage of skilled manpower. The necessity of nurturing manpower for self-maintenance was felt through identifying factors for successful smart factory introduction by companies and providing smart factory education. Therefore, the effects of educational satisfaction and operational competency on self-efficacy as a parameter and self-efficacy as a parameter were analyzed using research models and hypotheses to determine whether there was an effect between job satisfaction as a dependent variable. As a result of the analysis, it was found that the mediating effect of self-efficacy and self-efficacy on job satisfaction was found to have significant effects on operational competency and self-efficacy as parameters, as well as educational satisfaction and operational competency. The implication of this study is that continuous education and innovation activities are important in order to increase the business performance of companies, and through this, the manufacturing competitiveness of SMEs can be improved.
        4,000원
        8.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Naval weapons systems of the Republic of Korea are acquired through the Defense Planning Management System. Recently, acquisition of some naval ships have been delayed, and the causes of the delays have been recognized as inappropriate project management at the Execution Phase. However, we argue that the delay problem in naval ships acquisition should be approached, with due regard for the entire Defense Planning Management System. That is, We should try to investigate from Planning Phase to those of Programming, Budgeting and Execution Phases. Therefore, in this study, we investigated the actual cases of the delay in naval acquisition at all phases of the Defense Planning Management System. Based on the investigation, we tried to identify the naval ship Acquisition Delay Factors and find out the Weights of those factors. As the next step, we calculated the Influence Measures on the naval missions, including the Cost of Naval Capability Gap derived from the delays in acquisition of naval ships. As a final step, we calculated the Acquisition Delay Measures based on the interrelationship between the Acquisition Delay Factors and the Influence Measures. Then we evaluated and analyzed what the results stand for. Finally, we made suggestions for future improvement. The improvement suggestions we made for preventing delay in acquisition of naval ships in this study are as follows. First, we need a shift in perception. It is necessary to measure the Acquisition Delay Factors in acquiring naval ships and manage them from the Planning Phase. Second, resolution must be concerted efforts. All relevant agencies, not just a few, should work together to resolve the problems of acquisition delay. Third, analysis must be based on the accumulation of data. This allows the elaborating of naval ship Acquisition Delay Factors and Delay Measures. If this research method is applied to other military weapons systems in the future, we may be able to not just identify the Acquisition Delay Factors in acquisition of other military weapons systems, but also pursue improvement in those cases.
        4,200원
        10.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : In this study, the causality between smart parking user services and its satisfaction level was analyzed statistically, and a smart parking priority decision model was established in terms of the user side. METHODS :The results of the Daegu Metropolitan City survey for the parking state, parking fee, transfer, convenience of use, facilities, and safety that could influence smart parking user satisfaction were used. A structural equation model in SPSS 26 and AMOS 26 programs that facilitates hypothesis testing and importance factor analysis between observed and latent variables was used. RESULTS : The results demonstrated that the importance factor loading on smart parking user services was in the following order: convenience of use (0.996), parking facilities (0.814), safety (0.803), parking information (0.706), transfer (0.618), and parking fee (0.426). Among them, the parking fee was not quite influential in decision making. CONCLUSIONS : The most influential user service on smart parking information systems was the convenience of use, in which congestion in parking lots and parking time were the most influential variables. The most influential variables were in the following order: in parking facilities, the route design of vehicle flow and size of the parking garage; in safety, the entrance location and the level of wear; in the parking state, the availability of parking space and parking fees; and finally in transfer, the convenience of transfer to other modes and the number of transfer parking lots.
        4,000원
        11.
        2020.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Companies struggle to make their best products with high quality and service at a competitive price in global markets. However, customer needs and requirements keep changing with a variety of situations. Companies that face the changes can not stay the same and make an effort to adapt themselves to new circumstances. They would probably review the overall management system that is currently implementing to improve management efficiency. Among other things, quality might be considered to be a crucial element if they are manufacturing industries to be sustained in global markets. KSA (Korean Standards Association) is a government- affiliated organization under the Ministry of Trade, Infrastructure, and Energy. It is a Korean standards provider for quality and service industry. KSA confers national commendations for organizations, quality circles, artisans, QCEC (Quality Competitive Excellent Company), and the most honorable KNQA (Korean National Quality Award) every year. KSA established KNQA on the basis of Malcom Baldrige National Quality Award, Deming Prize, and European Quality Award. Research on quality awards shows that there are many similarities in the framework. Although KSA summarizes two factors for 13 evaluation indicators in the quality competitive excellent model of QCEC, the categorization is ambiguous to explain them according to earlier studies. We performed a deep analysis of foreign quality awards and background for KNQA and QCEC. We conducted a content analysis of KNQA and QCEC and matched evaluation items that were closely related. We proposed a quality competitiveness model with three factors, Technology, System, and Tools, summarizing 13 evaluation indicators in QCEC. Based on audit data for six years from 2012 to 2017 we carried out a confirmatory factor analysis for the proposed model by examining the model validity and fitness.
        4,200원
        12.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A new WRKY transcription factor gene was isolated by ESTs screening from a cDNA library of suspension cultured cells of Sweet potato (Ipomoea batatas). The 2,285 bp cDNA fragment, IbWRKY, was sequenced, from which a 505 amino acid residue protein was deduced. A search of the protein BLAST database identified significant similarity to other plant WRKY31 protein sequences. RT-PCR analysis showed expression patterns of IbWRKY31 in various intact tissues and suspension cultured cells of Sweet potato, and in leaves exposed to different stresses. The IbWRKY31 gene was highly expressed in suspension cultured cells. In leaf tissues, IbWRKY31 showed strong expression during salicylic acid and methyl jasmonate treatments. Expression of IbWRKY31 was also induced under various abiotic stress and pathogen infection conditions, such as wounding, H2O2, MV, PEG, NaCl, and bacterial pathogen infection. These results suggest that IbWRKY31 is involved in plant responses to various stress conditions, such as abiotic stresses and pathogen infection through a defense signaling pathway.
        4,000원
        14.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The stench of various sources has become a complex issue that all governments must face and solve. n-Butanol is often used as an odor intensity reference for daily air quality monitoring and evaluation. However, its odor space, including odor sensation and odor effect, is still not fully understood, especially in wide concentration ranges. This study described n-butanol odor character profiles with objective descriptors. They are mostly presented as “odorless” or “offensive” at low concentrations, and frequently characterized as “chemical” or “medicinal” at high concentrations. The semantic differential shows that n-butanol odor is a negative emotional odor rather than a positive one. The principal component analysis shows that the representative factors of the n-butanol sensibility structure according to the sensibility evaluation are expressed with diverse sensibility vocabulary, and ‘esthetics’ represent its characterless nature. The good linearity between intensity and concentration, the near absence of gender difference, diverse odor types rather than a specific type, and ease with which to make a wide range of concentrations, makes n-butanol a candidate to be considered as a suitable standard odorant.
        4,000원
        17.
        2018.10 구독 인증기관·개인회원 무료
        Host defense against pathogen invasion highly relies on immune defense machinery that is controlled by the nuclear factor-κB (NF-κB) of transcription factors. The Toll pathway are well known as an insect innate immune mechanism to protect host itself from invaded pathogens. Basically, in the edible insect, Tenebrio molitor, the Toll pathway is primarily activated by polymeric Lys-type peptidoglycans (PGNs), and components of fungal cell walls, β-1,3-glucan. Based on the current studies, the tremendous study has been focused on recognition and subsequent activation of spätzle in haemolymph, hence, there is a grave gap for intracellular event. Herein, in order to understand intracellular event of Toll signaling pathway, the Dorsal gene were identified. Moreover, domain analyses of TmDorsal2 gene indicate that there are two major domains such as Rel homology domain (RHD), ig-like, plexins, and transcription factors (IPT) domains. Based on the achieved results, TmDorsal2 mRNA was highly expressed in 1-day old pupa. Furthermore, TmDorsal2 was highly expressed in Malpighian tubules and fat body in last instar larvae (LL), and likewise mainly expressed in Malpighian tubules during adult 5-day old period, also the lowest expression of TmDorsal2 was observed in gonads. Moreover, TmDorsal2 mRNA levels after infection with E. coli appreciably went up at 6 and 9h time points. To investigate the effects of TmDorsal2 RNAi on larval susceptibility against various pathogens namely E. coli, S. aureus or C.albicans, dsRNA of TmDorsal2 has been synthesized the larvae dissected after 24h. As a result, TmAttacin1a, 1b and 2, TmDefencine1 and 2, TmTenecin1, 2, 3 and 4, TmCecropin2, TmColeoptericin1 and 2, Thaumatin-like protein 1 and 2 markedly reduced in the gut after injecting all mentioned microbes. In contrast, TmTenecin 2, Thaumatin-like protein 1 and 2 strikingly increased after microbe injection in the fat body. Interestingly, the most AMPs gene expression in whole body experimental case were upregulated. On the horizon, we will investigate effects of TmDorsal1 RNAi on larval susceptibility against various pathogens. Taken together, our studies may aid to understand insect innate immunity.
        18.
        2018.07 구독 인증기관·개인회원 무료
        This study reviews the SERVQUAL model theoretically and statistically in relation to the nonlinearity of the perceived service quality. Perceived service quality measurement based on the SERVQUAL model assumes that consumers evaluate service quality by comparing their perceptions with their expectations. However, previous studies adopt linear factor analysis to discuss the SERVQUAL model. The present study assumes that consumers evaluate the service quality with a standard to admit the difference between their expectations and perceptions, and that their perceived service quality follows a nonlinear response. A nonlinear SERVQUAL model based on a nonlinear factor analysis model is proposed to understand the characteristics. The proposed model employs a threshold specification that represents the space in which consumers admit their discrepancy. The study extends a nonlinear factor analysis model to a nonparametric model in order to examine the functional aspects that from the perceived service quality. A nonparametric SERVQUAL model is adopted without any assumptions of the functional form. The empirical studies on the retail sector shows that the nonlinear model performs better than the linear model, and that the nonparametric model estimates the nonlinear function for perceived service quality. The results from the proposed model in our study provide insights in a consumer’s perceived service quality recognized as nonlinear and asymmetric. We conclude that the functional form for perceived service quality should be considered when specifying the measurement model for SERVQUAL. In addition, we discuss future work for a nonlinear measurement model and a nonparametric factor analysis.
        20.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        마늘은 우리나라에서 가장 중요한 조미채소이지만 생산비용의 증가와 인력부족으로 재배 면적이 줄고 있다. 마늘 생산과정에서 노동력이 가장 많이 투입되는 작업은 파종작업으로 단 기간에 많은 시간과 노 력을 필요로 하는데 이런 문제점을 줄일 수 있는 마늘파종기의 개발은 필수적이라고 할 수 있다. 본 연 구는 세 가지 마늘크기에 대해서 일정한 간격으로 2립 파종이나 결주를 최소화 하여 점 파종을 할 수 있는 마늘파종기를 설계·제작하고자 수행하였다. 그 결과, 선별기를 통해서 마늘을 크기 별로 선별한 후 각 종자 크기에 맞는 배종 버킷을 부착하여 파종을 진행한다면 파종 성능을 높일 수 있을 것으로 나 타났다. 파종 성능 시험을 통해 중간 크기의 버킷을 부착하여 농가에서 종자용으로 가장 많이 사용하는 중간 크기의 마늘을 파종할 때 가장 낮은 결주율은 6.2%로 나타났다.
        4,000원
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