• Title/Summary/Keyword: 1/4 scale model

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Study on the basic efficiency of trawl net (트롤그물의 기본 성능에 관한 고찰)

  • Oh, Taeg-Yun;Kim, Young-Seuing;Choi, Seuk-Kwan;Bae, Jae-Hyun;Cho, Sam-Kwang;Park, Chang-Doo;An, Heui-Chun;Shin, Jong-Keun;Yang, Won-Seuk;Moon, Dae-Yeon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.42 no.3
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    • pp.148-157
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    • 2006
  • A model experiment, simulation test using personal computer and real sea trial fishing were carried out to investigate the basic efficiency of bottom trawl net which can be used in the sea mount of North West Pacific, and experimental values were analyzed as the values of full-scale bottom trawl net. Hydrodynamic resistance for the full-scale trawl net according to the Koyama equation was 2.1 times higher than that of simulation and 2.4 times higher than that of model experiment at the average towing velocity. At the 3.5kt's of towing speed, net width of the full-scale trawl net was 2.5% smaller than that of simulation and 8.2% larger than that of model experiment. On the fishing experiment of the full-scale trawl net for the 3.5kt's of average towing speed, average net height of A group(same direction with external force) was 423.5% higher than that of model experiment and 457.1% higher than that of simulation and that of B group(opposite direction with external force) were 283.8% and 306.3% higher than in case of model experiment and Simulation respectively. Net mouth of the full-scale trawl net was 338.1-504.6% higher than those of model experiment and simulation in A group, and 525.2-745.3% higher in B group.

Management Efficiency of High-growth Electrical and Electronics Industry (고성장 전기·전자사업의 경영효율성)

  • Kang, Da-Yeon;Lee, Ki-Se
    • The Journal of the Korea Contents Association
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    • v.19 no.8
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    • pp.151-158
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    • 2019
  • The high-technological in the electric and electronic industries is recognized in overseas markets as well. However, the competition for technologies in these industries is increasing. Therefore, electric and electronic firms should be more efficient in their production. so, This paper analyzes the efficiency of High-growth Electrical and Electronics firms using DEA model. We evaluate the CCR, BBC efficiency and RTS(return to scale) of 20 Korean high-growth Electrical and Electronics firms. There are a total of 12 efficient DMUs with a BCC of 1. There are a total of 4 efficient DMUs with a CCR of 1. A total of 11 DMUs were IRS in Scale Efficiency and a total of 6 DMUs were CRS in Scale Efficiency and a total of 3 DMUs were DRS in Scale Efficiency. We also suggest the Electrical and Electronics firms which can be benchmarked based on analyzed information.

Analysis of the Relationship of HOME, Socio-demographic Variables and Children's Intellectual and Social Abilities I - at Age Four - (HOME, 사회인구론적 변인과 아동의 지적, 사회적 능력간의 관계분석 I -만 4세 아동을 대상으로-)

  • 정영애
    • Journal of the Korean Home Economics Association
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    • v.27 no.1
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    • pp.181-194
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    • 1989
  • This study examined the characteristics of the relationship of HOME, socio-demographic variables and children's intellectual and social abilities. The subjects of this study were 80 children at age four and their mothers. Instruments included inventory of home stimulation (HOME) and the inventory of socio-demographic variables and K-Binet scale, social naturation scale, and the social-emotional developmental rating scale. The results obtained from this study were as follows: 1. HOME, socio-demographic variables had a significant positive correlation (.37∼..66) with children's intellectual ability. 2. HOME, Socio-demographic variables had a significant positive correlation(.26∼..67) with children's social ability. 3. The variables that significantly predicted children's intellectual ability were play materials, breadth of experience and quality of langage environment. 4. The variables that significantly predicted children's social ability were play materials, economic status of the home and parent education. 5. The results of the causal model showed that the kind of variables that affected children's intellectual ability directly were direct stimulation, parent's education, indirect stimulation, and the emotional climate of the home. 6. The results of the analysis of the causal model showed that the kind of variables that affected children's social ability directly were direct stimulation, parent's education, economic status of the home.

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Blink reflex changes and sensory perception in infraorbital nerve-innervated areas following zygomaticomaxillary complex fractures

  • Park, Young Sook;Choi, Jaehoon;Park, Sang Woo
    • Archives of Plastic Surgery
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    • v.47 no.6
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    • pp.559-566
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    • 2020
  • Background Infraorbital nerve dysfunction is commonly reported after zygomaticomaxillary complex fractures. We evaluated sensory changes in four designated areas (eyelid, nose, zygoma, and lip) innervated by the infraorbital nerve. This evaluation was conducted using the static two-point discrimination test and the vibration threshold test. We assessed the diagnostic significance of the blink reflex in patients with infraorbital nerve dysfunction. Methods This study included 18 patients, all of whom complained of some degree of infraorbital nerve dysfunction preoperatively. A visual analog scale, the infraorbital blink reflex, static two-point discrimination, and the vibration threshold were assessed preoperatively, at 1 month postoperatively (T1), and at a final follow-up that took place at least 4 months postoperatively (T4). The results were analyzed using a multilevel generalized linear mixed model. Results Scores on the visual analog scale significantly improved at T1 and T4. The infraorbital blink reflex significantly improved at T4. Visual analog scale scores improved more rapidly than the infraorbital blink reflex. Two-point discrimination significantly improved in all areas at T4, and the vibration perception threshold significantly improved in the eyelid at T4. Conclusions Recovery of the infraorbital blink reflex reflected the recovery of infraorbital nerve dysfunction. We also determined that the lip tended to recover later than the other areas innervated by the infraorbital nerve.

Development of Young Children's Understanding of Representational Relations (표상적 관계에 대한 영유아의 이해와 발달)

  • Park, Chan-Hyung;Lee, Jong-Hee
    • Korean Journal of Child Studies
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    • v.32 no.1
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    • pp.51-69
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    • 2011
  • This study examined how young children understand representational relations between referents and their representational objects. Ninety-four children aged 2- to 4.5-years of age were individually tested; firstly in the scale-model tasks, and then in the scale-map tasks. Data were analyzed both by means of Chi-Square test and by a more descriptive, micro analysis. According to the results, there were significant age differences in the understanding of representational relations, regardless of the type of representational objects. In the descriptive, micro analysis, it was found that before 3 years of age, young children have a great deal of difficulties in understanding representational relations. More importantly, young children under three seemed unable to understand representational relations, especially when the similarities as well as the differences between the representational object and the referent were very high. These results suggest that teachers of very young children need to select representational materials carefully, taking into consideration children's understanding of representational relations.

Effects of the Modifiable Areal Unit Problem (MAUP) on a Spatial Interaction Model (공간 상호작용 모델에 대한 공간단위 수정가능성 문제(MAUP)의 영향)

  • Kim, Kam-Young
    • Journal of the Korean Geographical Society
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    • v.46 no.2
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    • pp.197-211
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    • 2011
  • Due to the complexity of spatial interaction and the necessity of spatial representation and modeling, aggregation of spatial interaction data is indispensible. Given this, the purpose of this paper is to evaluate the effects of modifiable areal unit problem (MAUP) on a spatial interaction model. Four aggregation schemes are utilized at eight different scales: 1) randomly select seeds of district and then allocate basic spatial units to them, 2) minimize the sum of population weighted distance within a district, 3) maximize the proportion of flow within a district, and 4) minimize the proportion of flow within a district. A simple Poisson regression model with origin and destination constraints is utilized. Analysis results demonstrate that spatial characteristics of residuals, parameter values, and goodness-of-fit of the model were influenced by aggregation scale and schemes. Overall, the model responded more sensitively to aggregation scale than aggregation schemes and the scale effect on the model was varied according to aggregation schemes.

Studies on the Mackerel Purse Seine Operation in the Sea Area of Cheju Island - 1 . Model Experiment on the Changes of Net Shape in Stagnant Water - (제주도 주변해엽 고등어 포착망의 연구 - 1 . 정수에 있어서 망형 변화에 관한 모형실험 -)

  • 박정식
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.22 no.2
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    • pp.7-15
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    • 1986
  • In order to investigate the performance for the mackerel purse seine of one boat purse seiner using in the sea area of Cheju Island, a model net is made of the scale of 1/400 of its full scale, and model test on the shape of net and the tension of purse line is carried out in the stagnant water channel of the circulating water tank. Designing and testing for the model net are based on the Tauti's law. The obtained results are as follows; 1. The sinking rate of net is maximized the value of 6.40 m/min from 5 to 10 minutes after shooting net, and the mean value is 6.13 m/min. 2. The enclosed area formed with the float line after pursing operation is 76-84% of the area which is formed immediately after the shooting operation. At that time, purse seine is pulled inward the circle of surrounding net about 26.5% of the diameter. 3. In operating, when longitudinal section area of the central part of the net is maximized, the split area of both the wing-ends is 31-32% of the former. 4. When the time for the completing of pursing is 20 minutes, the maximum tension of the purse line is about 10.2 tons.

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Assessment of End Condition of Drilled Shafts Socketed into Rock by Impact Echo Test (충격반향기법을 이용한 암반근입 현장타설말뚝의 선단조건 평가)

  • 김형우;김동수;김원철
    • Journal of the Korean Geotechnical Society
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    • v.18 no.4
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    • pp.21-32
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    • 2002
  • Small and full scale model tests were performed to obtain the transient responses of shafts subjected to elastic impact by impact-echo test. Four end conditions of drilled shafts were considered: (1) free, (2) fixed, (3) rock-socketed, and (4) soft bottom. In small scale model tests, mock-up shafts were fabricated to simulate these four drilled shafts using poly-urethane and plastic material. Additionally, skin frictions between shaft and rock were changed to find out the effect of side contact on dynamic responses. All impact responses were tested in the air. Subsequently, full scale model tests were also carried out on concrete shafts that were in free and rock-socketed condition. The end conditions of the drilled shafts could be identified with good reliability by the waveforms from both small and full scale model tests. The results obtained in this study will provide an improved understanding of the impact responses for end conditions, especially for rock-socketed drilled shafts that are frequently designed and built in Korea.

Development of four-equation turbulence model for prediction of mixed convective heat transfer on a flat plate (수평평판위 의 혼합대류 열전말 계산 을 위한 4-방정식 모델 의 개발)

  • 성형진;정명균
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.7 no.2
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    • pp.193-203
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    • 1983
  • The mixed convective heat transfer problems are characterized by the relatively significant contribution of buoyancy force to the transport processes of momentum and heat. Past analytical studies on this kind of problems have been carried out by employing either the conventional R-.epsilon. turbulence model which includes constant turbulent Prandtl number .sigma.$_{+}$ 1 or an extended R-.epsilon. turbulence model which takes account of the buoyancy effect in appropriate length scale equations. But in the latter case, the temperature variance .the+a.$^{2}$ over bar is approximated by a model under local equilibrium condition and the time scale ratio between velocity and temperature is assumed to be constant. These approximation is known to break down when the buoyancy effect is dominant. The present study is aimed at development of new computational turbulence closure level which can be applied to this rather complex turbulent process. The temperature variance is obtained directly by solving its dynamic transport equation and the time scale ratio which is variable in space is computed by a solution of a dynamic equation for the rate of scalar dissipation .epsilon.$_{\thetod}$ It was found that the computational results are in good agreement with available experimental data of wide range of unstable conditions.

The Conceptual Framework of Building Fashion Brand Equity; Focused on casual wear brand (패션브랜드자산의 형성과정에 관한 연구: 캐주얼 브랜드를 중심으로)

  • 김혜정;임숙자
    • Journal of the Korean Society of Clothing and Textiles
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    • v.28 no.2
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    • pp.252-261
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    • 2004
  • In this complex marketing world, marketers find themselves having to grapple with difficult issues about branding and their brand management. In many cases, a deeper understanding of how consumers feel, think, and act could provide valuable guidance to address these brand-management challenges. The objective of this study is to conceptualize and test the framework of building fashion brand equity, utilizing Keller's CBBE Model as a theoretical framework and Kim and Lim's (2002) scale as a measurement model of fashion brand equity. We conducted a survey toward 696 university students using Kim and Lim's fashion brand equity scale. To test the hypothesized building paths of fashion brand equity, statistical analyses were performed with AMOS 4.1 program using confirmatory factor analysis and structural equation model. The results of this study were as follows. First, fashion brand equity was defined in terms of six components; customer-brand resonance, customer feeling, customer judgment, brand imagery. brand performance and brand awareness. Fashion brand equity was multi-dimensional brand attitude, which could be measured by 16 items. Consequently, Kim and Lim's scale acquired a statistical validity. Second, the proposed conceptual framework of this study was partially significant. We can provide an effectiveness of Keller's CBBE model to conceptualize the building process of fashion brand equity. Third, it was different between two brands to build fashion brand equity.