• 대한조선학회논문집
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• 제60권5호
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• pp.296-304
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• 2023

Cavitation tests for a waterjet propulsor of an amphibious vehicle are carried out in the Large Cavitation Tunnel. Waterjet pump performances and cavitation characteristics including thrust breakdown performances are investigated in the tests. In addition, cavitation characteristics for waterjet propulsors working inside the intake are calculated by using a commercial CFD code, Star-CCM+. Sliding mesh is implemented to a rotating impeller and the k-epsilon turbulence model is chosen. Cavitation bubble growth and collapse are estimated using the Schnerr-Sauer cavitation model based on Rayleigh-Plasset equation. Calculated results agree fairly well with experimental results. The re-design of the waterjet propulsor is performed to enhance waterjet cavitating performances and calculated results show that waterjet thrust breakdown characteristics are significantly improved.

• Asian-Australasian Journal of Animal Sciences
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• 제7권4호
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• pp.563-570
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• 1994

Fifty-one Thai Native (TN) and Anglo-Nubian (AN) $\times$ TN does were studied. The purpose of the study was to investigate the reproductive performances of different goat genotypes grazing improved pasture with or without supplementary feeding. The feeding regimes were: 1. no concentrate supplement (T1), 2. supplemented for 15 days before mating and 45 days during mating period (T2), 3. supplemented from 15 days before mating to 42 days after kidding (T3) and 4. supplemented for 30 days before kidding, followed by 42 days after kidding. Cross-bred does tended to have higher conception rates, kidding opportunities and higher multiple birth rates than TN does. However, these differences were not statistically significant (p>0.05), and concentrate supplementation under the various regimes did not increase reproductive performance. TN kids had significantly (p<0.01) lower birth weights and lower weights at 3, 6 and 12 weeks of age than those of the cross-bred kids. However, there was no significant difference between the genotypes in growth rate (g/d or $g/kg^{75}/d$) of kids during these periods. Supplementary feeding did not significantly affect either kid birth weight or weight gain in the first 6 weeks after birth and during this period supplementary adequate in both quantity and quality, substantial reproductive performances were achieved from both TN and AN $\times$ TN does without concentrate supplementation.

• 대한안전경영과학회지
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• 제14권4호
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• pp.247-258
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• 2012

It seems most important for a manufacturing company to be well aware of its relationship with suppliers. This is why it is essential to analyze and control the structural relationship among CEO's characteristics, relations between suppliers and manufacturers and new product development performances affected by such relations. The present study may be summed up as follows: First, from the analysis of characteristics of manufacturing company's CEO and relations between suppliers and manufacturers, it could be verified that CEO's characteristics exercised influence upon sharing of product development process and upon cooperation for technical manpower, but not upon sharing of core technologies, signifying the fact that nothing could be more important than the role of CEO who has strong will to improve his or her relations with suppliers; and Second, from the analysis of relations between suppliers and manufacturers as well as relations between management and new product development performances, it became evident that both management performance and product development performance were affected by sharing of product development process. It was also known that cooperation for technical development process had influence upon the product development performance but not upon the management performance. Furthermore, the analysis showed that both management performance as well as product development performance were affected by sharing of core technologies.

• International Journal of Fluid Machinery and Systems
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• 제1권1호
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• pp.57-63
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• 2008

To optimize the stationary components in the multistage centrifugal pump, the effects of the return vane profile on the performances of the multistage centrifugal pump were investigated experimentally, taking account of the inlet flow conditions for the next stage impeller. The return vane, whose trailing edge is set at the outer wall position of the annular channel downstream of the vane and which discharges the swirl-less flow, gives better pump performances. By equipping such return vane with the swirl stop set from the trailing edge to the main shaft position, the unstable head characteristics can be also suppressed successfully at the lower discharge. Taking the pump performances and the flow conditions into account, the impeller blade was modified so as to get the shock-free condition where the incidence angle is zero at the inlet.

• 한국자동차공학회논문집
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• 제5권4호
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• pp.21-28
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• 1997

The vehicle handling performances have a close relation with the driver's safety. And the CAT(Computer aided testing) system has been introduced as a powerful tool for improving the handling performances. In this study, a CAT system for effectively measuring and analysing the handling performances is developed based on the windows GUI(Graphic user interface) environment. Especially, in order to derive a lot of significant handling performance parameters from a series of proving ground tests, the CAT system has various functions related to real time measurement, time domain analysis, frequency domain analysis, steady state analysis and so on.

• 음성과학
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• 제14권3호
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• pp.147-160
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• 2007

This study was aimed to evaluate effect of parents-centered speech intervention program on overall speech and language performances of children with cochlear implant. Ten pairs of mother and child were selected and assigned into two groups: intervention group(G1) and control group(G2). G1 included 5 children with cochlear implant and their mothers who joined the parents-centered program. G2 consisted of 5 children with cochlear implant and their mothers did not participate in the program. To evaluate their speech and language abilities, examination instruments(Preschool Language Scale, and Language Comprehension and Cognition Test) were analyzed. Performances of pre- and post-treatment were analysed by ANOVA procedure. The results were as follows: There were significant differences of speech and language performances between pre- and post-treatment in G1. But there were no significant differences in G2(therapists centered program). G1 showed better performances in language comprehension than G2. This study revealed that parents centered language intervention program would be effective for speech and language development for children with cochlear implant.

• 한국실내디자인학회논문집
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• 제21권5호
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• pp.328-335
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• 2012

Due to development of digital technology, a concept of stage design management is being changed. In addition, stage management technique is changing a viewpoint of the audience watching a stage through the convergence of analogue and digital technology. Three-dimensional media such as LED and hologram and works combining with previous stage performances are rising, and the audience's requirements about spectacles on the stage are increasingly higher. Interaction between a stage, audiences and actors is a communication tool by a work story and its direction. In other words, stage design should newly focus on not only concluded work story but also comprehensive delivery of direction and the expression and extreme delivery. Therefore, this study aims to examine how to combine analogue and digital direction elements in the stage design. To this end, this study looks into everything the audience feels through performances and analogue and digital elements directed for performances and then analyzes and arranges them to present a possibility of various types of work performances. Stage structure, set, and lighting that are analogue direction elements are the basis of stage performance. Analogue direction elements mean a media vehicle that can differentiate except for basic direction of each work. This study aims to analyze new performance culture when analog and digital direction elements are combined through stage performance and a possibility of new stage performance. In addition, through this it desired to seek for a development possibility of Korean leisure culture and art culture. As the work cases, this study shows 10 works through actual stage performances held in Korea and introduces elements directed in those works.

• 기술혁신학회지
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• 제11권4호
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• pp.431-449
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• 2008

본 연구는 정보통신 연구개발사업인 ITRC사업을 대상으로 대학연구개발의 동기, 전략, 및 성과간의 관계를 분석을 하였다. 이를 위하여 기존연구를 기반으로 '동기-전략, 환경요인-전략, 및 환경요인-성과 간의 관계'에 관한 연구모형을 설정하였으며, 아울러 설문조사에서 얻어진 데이터를 활용한 통계분석을 통하여 가설을 검증하였다. 가설검증 결과에 대한 종합적인 판단을 통하여 대학에서의 연구개발전략 수립 및 수행에 관련된 정책적인 제언을 하고자 하였으며, 아울러 실제 대학 연구개발성과의 활용도 및 기여도 제고를 위한 정책적 제언도 병행하였다.

• 한국해양공학회지
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• 제26권1호
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• pp.41-46
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• 2012

A deep-sea manganese nodule miner consists of 4 parts: the pickup device, crusher, disposal device, and tracked vehicle. The tracked vehicle is an essential component to keep the self-propelled miner moving across deep-sea soil. The performances of the tracked vehicle are influenced by noise factors: the shear strength of the seafloor, bottom current, seafloor slope, track speed, reaction forces of flexible hose, etc. It is necessary to adopt a robust design method that improves the performances and minimizes the variation caused by noise factors. Taguchi's method, the most widely known robust design method, searches for the robust optimum using an orthogonal array composed of the product of the inner array and outer array. In this paper, we propose a new screening technique to reduce the number of input factors and apply the MRSN (Multi-Response Signal to Noise) ratio to convert multiple performances into single one in order to overcome the difficulties and limitations of using Taguchi's method in a case with many input factors and multiple performances. A test miner was already designed and tested. It has about 1/10 the capacity of a commercial one and was successfully operated at an in-shore area. Taguchi's robust design was applied to the tracked vehicle of the test miner, and design improvements were implemented for the vehicle.

• 유통과학연구
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• 제14권1호
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• pp.67-74
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• 2016

Purpose - In this paper, the degree of similarity and dissimilarity between pairs of 50 major cities in China can be shown on the basis of three evaluation variables(internet businessman index, internet shopping index and e-commerce development index). Dissimilarity distance matrix is used to analyze both similarity and dissimilarity between each fifty city in China by calculating dissimilarity as distance. Higher value signifies higher degree of dissimilarity between two cities. Cluster analysis is exploited to classify 50 cities into a number of different groups such that similar cities are placed in the same group. In addition, multidimensional scaling(MDS) technique can obtain visual representation for exploring the pattern of proximities among 50 major cities in China based on three development performance attributes. Research design, data, and methodology - This research is performed by the 2013 report provided with AliResearch in China(1/1/2013~11/30/2013) and utilized multivariate methods such as dissimilarity distance matrix, cluster analysis and MDS by using CLUSTER, KMEANS, PROXIMITIES and ALSCAL procedures in SPSS 21.0. Results - This research applies two types of cluster analysis and MDS on three development performances based on the 2013 report of Aliresearch. As a result, it is confirmed that grouping is possible by categorizing the types into four clusters which share similar characteristics. MDS is exploited to carry out positioning of both grouped locations of cluster and 50 major cities belonging to each cluster. Since all the values corresponding to Shenzhen, Guangzhou and Hangzhou(which belong to cluster 1 among 50 major cities) are very large, these cities are superior to other cities in all three evaluation attributes. Twelve cities(Beijing, ShangHai, Jinghua, ZhuHai, XiaMen, SuZhou, NanJing, DongWan, ZhangShan, JiaXing, NingBo and FoShan), which belong to cluster 3, are inferior to those of cluster 1 in terms of all three attributes, but they can be expected to be the next e-commerce revolution. The rest of major cities, in particular, which belong to cluster 4 are relatively inferior in all three attributes, so that this automatically evokes creative innovation, which leads to e-commerce development as a whole in China. In terms of internet businessman index, on the other hand, Tainan, Taizhong, and Gaoxiong(which belong to cluster 2) are situated superior to others. However, these three cities are inferior to others in an internet shopping index sense. The rest of major cities, in particular, which belong to cluster 4 are relatively inferior in all three evaluation attributes, so that this automatically evokes innovation and entrepreneurship, which leads to e-commerce development as a whole in China. Conclusions - This study suggests the implications to help e-governmental officers and companies make strategies in both Korea and China. This is expected to give some useful information in understanding the recent situation of e-commerce in China, by looking over development performances of 50 major cities. Therefore, we should develop marketing, branding and communication relevant to online Chinese consumers. One of these efforts will be incentives like loyalty points and coupons that can encourage consumers and building in-house logistics networks.