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        검색결과 1,566

        269.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fumigation of fruits and vegetables during quarantine and pre-shipment (QPS) treatment should be effective with a shorter fumigation time to minimize phytotoxicity. In this research study, a shorter fumigation time, 2 hours exposure which is shorter than that of the current commercial fumigation procedures using a lower dose of ethyl formate (EF) mixed with phosphine (PH3) on strawberry was investigated. The reciprocal effect between EF and PH3 against nymphs and adult Myzus persicae (Sulzer) and Tetranychus urticae (Koch) was evaluated. In addition, L(Ct)50 and L(Ct)99 of EF only and EF mixed with PH3 were analyzed at 5°C and 20°C. The synergistic ratio (SR) of L(Ct)50 and L(Ct)99 for the nymph and adult stages of M. persicae were >1.0, which indicated a synergistic effect between EF and PH3. However, the SR values of L(Ct)50 and L(Ct)99 of the nymph and adult stages of T. urticae were ≤1.0 indicating that there was no synergistic effect between the two fumigants against T. urticae. Our results showed that the reciprocal effect between EF and PH3 has different effects on M. persicae and T. urticae. This could be attributed to the biological and physical differences between the class Arachnida and Insecta. The synergistic effect between EF and PH3 against M. persicae within a shorter exposure period and without phytotoxicity on fruits and vegetables will significantly benefit the horticultural industry.
        4,000원
        270.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As competition among companies has intensified and the life cycle of products has been shortened, strong innovation is needed to meet consumers' needs. In addition, it is necessary to shorten the life cycle of the product and reduce the time required for technology development for the competitive advantage of the product. In particular, venture companies where new technologies and ideas are important require more innovative capabilities than others companies. Therefore, this study analyzed the impact of technology innovation capabilities (product development process capability, human resource capability and financial capability) on sales by technology development for small and medium venture companies and analyzed moderating effect of technology development period on the relationship between technology innovation capabilities and sales by technology development. The data of 'Small and Medium Business Technology Statistics' collected by the government every year were used for analysis. Technology-intensive ventures were extracted from this data. In addition, the moderating effect was analyzed through hierarchical regression analysis. This study shows that product planning capability, test capability, and R&D expenditure have a positive impact on sales by technology development. In this study, the product development period showed a positive moderating effect on product development capability and sales performance. On the other hand, the product development period showed a negative moderating effect on R&D expenditure and sales by technology development.
        4,000원
        271.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        There is a growing interest in project management knowledge, project management information systems, and process improvement to systematically project execution in public sectors, achieve high performance and value, and increase the effectiveness of the overall industry. In particular, the software industry is a knowledge-intensive industry centered on professional manpower. This study examines the effect of the project managers' competences of regional SW promotion agencies on and project performance and the moderating effect of the level of project management maturity. We collected data using a questionnaire to the project managers of regional SW promotion agencies. In this study, a structural equation model was used to analyze the relationship between project managers’ competences and performance. In addition, a multi-group structural equation model was used to analyze the moderating effect according to the high and low project maturity. As a result of the analysis, it was found that only contextual competence among the competences of the project manager had a positive effect on project performance. It was found that technical and behavioral competence did not have a positive effect on management and completion performance. It was found that the moderating effect according to the maturity of business management of local institutions was not significant.
        4,000원
        272.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Barnyard millet is a short-lived tropical, short-term C4 plant and has superior vitality in humid conditions owing to its freshwater habitat. It shows strong adaptability to soils with poor drainage and low fertility, and efficiently competes with rice in paddy fields. Barnyard millet grain is used as feed in the Indian region and is a great source of dietary fiber, proteins, fats, vitamins, and some essential amino acids. Considering its high nutritional value and its potential as a food resource and fodder crop, various countries are showing interest in cultivating barnyard millet. However, in Korea, farm households have not yet recognized the benefits of cultivating barnyard millet, and research regarding this is scarce. In this review, the features of forage barnyard millet and its related research trends are discussed, with the aim of improving interest in this crop and promoting its cultivation.
        4,000원
        273.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The development of IOT technology and artificial intelligence technology is promoting the smartization of manufacturing system. In this study, data extracted from acceleration sensor and current sensor were obtained through experiments in the cutting process of SKD11, which is widely used as a material for special mold steel, and the amount of tool wear and product surface roughness were measured. SVR (Support Vector Regression) is applied to predict the roughness of the product surface in real time using the obtained data. SVR, a machine learning technique, is widely used for linear and non-linear prediction using the concept of kernel. In particular, by applying GSVQR (Generalized Support Vector Quantile Regression), overestimation, underestimation, and neutral estimation of product surface roughness are performed and compared. Furthermore, surface roughness is predicted using the linear kernel and the RBF kernel. In terms of accuracy, the results of the RBF kernel are better than those of the linear kernel. Since it is difficult to predict the amount of tool wear in real time, the product surface roughness is predicted with acceleration and current data excluding the amount of tool wear. In terms of accuracy, the results of excluding the amount of tool wear were not significantly different from those including the amount of tool wear.
        4,000원
        274.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Several studies investigating the behavior and environmental distribution of rare earth elements (REEs) have been reviewed to determine the geochemical processes that may affect their concentrations and fractionation patterns in groundwater and whether these elements can be used as tracers for groundwater-rock interactions and groundwater flow paths in small catchments. Inductively coupled plasma-mass spectrometry (ICP-MS), equipped with an ultrasonic nebulizer and active-film multiplier detector, is routinely used as an analytical technique to measure REEs in groundwater, facilitating the analysis of dissolved REE geochemistry. This review focuses on the distribution of REEs in groundwater and their application as tracers for groundwater geochemistry. Our review of existing literature suggests that REEs in ice cores can be used as effective tracers for atmospheric particles, aiding the identification of source regions.
        4,000원
        275.
        2021.08 KCI 등재 구독 인증기관·개인회원 무료
        벗초파리기생벌인 A. japonica의 벗초파리 유충의 발육단계에 따른 기생특성과 기생당한 유충과 번데기에서 형태적인 차이를 조사하였다. 또한 A. japonica의 우화기간이 벗초파리 우화일수 보다 더 소요되는 것을 확인하였다. A. japonica는 벗초파리 유충에 효과적인 기생 및 살충 효과를 나타내었으며 벗초파리 방제를 위한 천적으로 활용이 가능할 것으로 보인다.
        276.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 안경광학과 대학생을 대상으로 일반적 특성과 전공만족도, 안경사 직업관을 조사하여 안경사 직업관에 영향을 미치는 요인을 파악하고자 하였다. 방법 : 충남지역 안경광학과 대학생 196명을 대상으로 일반적 특성(11)과 전문적 자아 개념(5), 사회적 인식 (5), 안경사의 전문성(5)의 총 26개 문항을 온라인 설문 조사하였다. 분석방법은 SPSS 18.0 통계프로그램을 사용하였으며 통계적으로 유의수준은 p<0.050 기준으로 하였다. 결과 : 전문적 자아 개념에는 전공 만족도(β =0.36, p<0.001)와 연령(β =-0.20, p=0.002)이 유의한 영향을 미치는 것으로 나타났다. 사회적 인식에는 전공 만족도(β =0.33, p<0.001)와 연령(β =-0.31, p<0.001)이 유의 한 영향을 미치는 것으로 나타났고, 안경사의 전문성에는 전공 만족도(β =0.33, p<0.001)가 유의한 영향을 미치는 것으로 나타났다. 결론 : 안경광학과 학생들이 생각하는 안경사의 전문적 자아개념, 사회적인식, 전문성에 대한 전공만족도와의 상관관계가 유의하였다. 이는 재학생들의 전공 만족도가 높을수록 직업적 인식이 높다는 것을 나타내는 연구결과로 안경광학과 학생들의 진로 지도를 위한 기초자료로 활용 되어질 수 있을 것으로 사료된다.
        4,000원
        277.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Doublesex and mab-3 related transcription factor (dmrt) play crucial roles in sex determination and sex differentiation in vertebrates and invertebrates. Although dmrt genes have been identified in vertebrates, little is known about aquatic invertebrates. In this study, two dmrt genes, namely, Dc_dmrt93B and Dc_dmrt99B, were identified from brackish water flea, Diaphanosoma celebensis. Transcriptional changes were observed in the dmrt genes when the flea was exposed to bisphenol (BP), an endocrine disruptor. Sequence and phylogenetic analyses showed that both dmrt genes contained two conserved domains, namely, DM and DMA, closely clustered with those of Daphnia spp. Additionally, a significant increase in the Dc_dmrt99B mRNA expression level was observed upon exposure to intermediate concentrations of BP (bisphenol A>bisphenol S=bisphenol F, p<0.05), while the expression of Dc_dmrt93B mRNA was slightly modulated. These findings imply that the two dmrt genes may be involved in sex differentiation of D. celebensis. Furthermore, it was found that the ability of BP to modulate dmrt genes could affect development and reproduction. This study provides a basis for understanding the function of the dmrt genes and the molecular mode of action of BP in small crustaceans.
        4,000원
        278.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Due to increasing awareness on the treatment of end-of-use/life products, disassembly has been a fast-growing research area of interest for many researchers over recent decades. This paper introduces a novel lot-sizing problem that has not been studied in the literature, which is the service-parts lot-sizing with disassembly option. The disassembly option implies that the demands of service parts can be fulfilled by newly manufactured parts, but also by disassembled parts. The disassembled parts are the ones recovered after the disassembly of end-of-use/life products. The objective of the considered problem is to maximize the total profit, i.e., the revenue of selling the service parts minus the total cost of the fixed setup, production, disassembly, inventory holding, and disposal over a planning horizon. This paper proves that the single-period version of the considered problem is NP-hard and suggests a heuristic by combining a simulated annealing algorithm and a linear-programming relaxation. Computational experiment results show that the heuristic generates near-optimal solutions within reasonable computation time, which implies that the heuristic is a viable optimization tool for the service parts inventory management. In addition, sensitivity analyses indicate that deciding an appropriate price of disassembled parts and an appropriate collection amount of EOLs are very important for sustainable service parts systems.
        4,300원