• Title/Summary/Keyword: Asymmetric factors

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A Study of Cogging Torque Reduction depending on Notch Position of Single Phase BLDC Motor Stator (단상 BLDC 전동기 고정자 노치 위치에 따른 코깅토크 저감에 관한 연구)

  • Kam, Seung-Han;Jung, Tae-Uk
    • Journal of the Korean Society of Industry Convergence
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    • v.17 no.3
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    • pp.113-121
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    • 2014
  • This paper presents a optimization design of 10[W] single phase BLDC motor applied Notch shape. Cogging Torque causes noise, vibration and torque ripple so notched stator is proposed in this paper. Firstly, a single phase BLDC motor needs applying aymmetric air-gap shape because this type motor cannot help having dead-point which is zero torque position. However, using asymmetric air-gap structure causes cogging torque increase. Therefore, this paper proposes the notch shape structure. Notch shape structure has some advantages; low cost, easy to apply. There are 4 optimal factors selected in optimization process, which are position and size of notches. Through building a prototype, the result of FE analysis and the experimental measurement value are compared each other and then vailidity and utility of simulation will be verified.

Advanced Cryo-Electron Microscopy Technology: High Resolution Structure of Macromolecules

  • Chung, Jeong Min;Jung, Hyun Suk
    • Applied Microscopy
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    • v.46 no.1
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    • pp.1-5
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    • 2016
  • Recent cryo-electron microscopy (EM) studies reported the structure of various types of proteins at high resolution which is sufficient to visualize the intermolecular interaction at near atomic level. There are two main factors that cause the advances in cryo-EM; the development of image processing techniques, such as single particle analysis, and the improved electron detection devices. Although the atomic structures of small and asymmetric proteins are not yet to be determined by cryo-EM, this striking improvement implies the bright prospect of the application in biomedical studies. This study reviews the recently published studies reported high resolution structures using improved imaging analysis techniques and electron detectors. Furthermore, we will discuss about the future aspects of cryo-EM application.

The Quality Crisis and Response at Hyundai and Toyota Motor (현대와 도요타의 품질 위기와 극복)

  • Hyun, Young-Suk;Chung, Kyu Suk
    • Journal of Korean Society for Quality Management
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    • v.42 no.1
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    • pp.91-109
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    • 2014
  • Purpose: This study compares quality crisis and management at Hyundai Motor in the late 1990s and Toyota Motor in the late 2000s. We can expect to induce more meaningful policy implications in quality management from this in-depth comparative case study. Methods: This study compares two cases at Hyundai and Toyota Motor how to overcome quality crisis based on the OESP (Organization-Environments-Strategy- Performance) model. Results: Hyundai Motor shows centralized approach based on the asymmetric organizational culture and the entrepreneurial leadership but Toyota shows decentralized, systematic approach based on the steady state leadership and symmetric organizational culture. The CEO's leadership have proved to be one of the important factors at both companies. Conclusion: The effective quality management in global contexts has become more and more difficult for the 'complexity explosions' in automobile industry. As a consequence, the future competitive edge of world automobile industry will come from the effective quality management of products in global contexts.

Stereoselective Reduction of Methyl Vinyl Ketone Dimer

  • Jun, Jong-Gab;Shin, Dong-Gyun;Lee, Chang-Kiu;Sin, Kwan-Seog
    • Bulletin of the Korean Chemical Society
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    • v.11 no.4
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    • pp.307-309
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    • 1990
  • The stereoselectivity of the reaction between methyl vinyl ketone dimer, which contains two possible sites of chelation, and zinc borohydride or diisobutylaluminum hydride has been studied in order to illuminate the factors involved in the high levels of asymmetric induction obtained in the bicyclic system. The conditions for the formation of the exo-5,7-dimethyl-6,8-dioxabicyclo[3.2.1]octane are DIBAH reduction of MVK dimer in ether at reflux followed by acidic cyclizatioan, and for the endo isomer are $Zn(BH_4)_2$ reduction with $ZnCl_2$ at $0^{\circ}C.$.

The auditory evoked potential in premature small for gestational age infants (미숙아로 태어난 부당 경량아의 청각유발전위검사)

  • Moon, Il Hong;Ha, Kee Soo;Kim, Gui Sang;Choi, Byung Min;Eun, Baik-Lin;Yoo, Kee Hwan;Hong, Young Sook;Lee, Joo Won
    • Clinical and Experimental Pediatrics
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    • v.49 no.12
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    • pp.1308-1314
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    • 2006
  • Purpose : This study aimed to evaluate the usefulness of auditory evoked potential (AEP) in clarifying neuronal development in premature small for gestational age (SGA), and appropriate for gestational age (AGA) infants. Methods : A total of 183 premature infants who were born from August 2002 to July 2005, were examined with AEP. They were divided into three groups; AGA, symmetric-SGA and asymmetric-SGA group. Results : Statistically significant differences in the head circumference were observed in three groups. Among the risk factors, prevalence of hypoglycemia and hypoalbuminemia between AGA and asymmetric SGA infants were significantly different. V absolute peak latency (APL) in the right side of AGA infants was delayed were than that of asymmetric SGA infants. III-V interpeak latency (IPL) of asymmetric SGA infants was delayed more than that of symmetric SGA infants. Moreover, I-V IPL on both sides of symmetric SGA infants was shortened more than that of AGA infants. However, all the results of AEP were within the reference range, according to gestational age. Birth weight of, only asymmetric SGA, was related to the III APL on both sides and the III-V IPL on right side. Conclusion : This study shows that the values of APL and IPL of premature SGA infants are different than that of premature AGA infants. These data could be an indicator in evaluating the neurologic functions of small for gestational age infants.

A Study on Design Factor of Insole using Shape Memory Alloy for Pes Planus Correction (평발교정용 형상기억합금 초탄성 인솔 설계 연구)

  • Yang, Mi Kyung;Lee, Sang-Wook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.5
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    • pp.79-85
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    • 2017
  • As the number of patients suffering from Pes Planus increases, research on a correctional insole that can cope with them is increasingly required. Therefore, the design of an insole for Pes Planus Correction was studied using the superelastic effect, which is one of the characteristics of the shape memory alloy in this paper. To design an effective insole, the effect of the contact pressure induced by the insole on the plantar fascia, which is the most important muscle in the foot structure, was evaluated. Three parameters (thickness, max. height and asymmetric ratio) were set as the main design factors of the insole, and the maximum contact pressure appearing on the plantar fascia was calculated by finite element analysis and analyzed using the Taguchi method. As a result of the analysis, it was confirmed that the contact pressure was influenced in the order of max. height, thickness, and asymmetric ratio. In addition, the contact pressure was converted to a feeling pressure that could be felt by a person, and then a safety correction range was established that would not cause any irritation to the plantar fascias, even though the correction effect could be expected. This indicates the best design for the safety correction range. The design method considering the important factors established through this study can form the basis for designing a personalized correctional insole in the future.

The Treatment Strategies of Non-surgical Approach for Dentofacial Asymmetry Patient (치열 안면 비대칭 환자의 비수술적 절충치료의 전략적 접근)

  • Lee, Kyung-Min;Lee, Sang-Min;Yang, Byung-Ho;Yun, Min-Sung;Lee, Ju-Hee
    • Journal of Dental Rehabilitation and Applied Science
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    • v.26 no.1
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    • pp.77-87
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    • 2010
  • Skeletodental asymmetries are common and asymmetric orthodontic treatments are very difficult to correct successfully. The cause of asymmetries can be the skeletal asymmetry, dental, or functional, or combinations of these causes. Skeletodental asymmetries can be the result of congenital factors, such as hemifacial microsomia and environmental factors, such as trauma. Optimal treatment outcome of the severe facial asymmetry requires the orthognathic surgery. Mild asymmetry problem can be treated by only orthodontic treatment. The orthodontic treatment of asymmetry is usually difficult. Facial asymmetry orthodontic treatment are primarily based on proper diagnosis and careful treatment planning. Side effects of asymmetric elastic to treat midline discrepancies are canted occlusal plane, tipped incisors and unesthetic results. In the management of dental arch asymmetries, the clinician should select the appropriate force system and the appliance design necessary to address the asymmetry while minimizing undesirable side effects. This report presents treatment strategies for the treatment of skeletodental asymmetry. In this case report, the clinical case with midline discrepancies treated by optimal mechanics is described. Through diagnosis and strategic treatment mechanics can obtain proper midline correction with minimal side effects.

Regional Difference of Project Finance and Its Policy Implications (프로젝트 금융의 지역적 차별성과 정책적 시사점)

  • Park, Won-Seok
    • Journal of the Economic Geographical Society of Korea
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    • v.11 no.4
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    • pp.580-599
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    • 2008
  • This paper aims at examining the existence and characteristics of regional difference in project finance in Korea. Main results of this paper are as follow. Firstly, regional difference in project finance between capital region and local can be seen partially. However, their characteristics are different from corporate finance. ANOVA tests show significant differences of excess interest rate occur in case of commercial real estate projects and significant differences of contracted terms occur in case of residential real estate projects carried out by local banks. Secondly, key factors causing the regional differences in project finance are asymmetric information for cash flow generated by the project between the capital region and local. Especially, regional differences in project finance are different from those in corporate financing because of local banks$^{\circ}{\phi}$ behaviors. They follow and act as the passive members of nationwide banks in case of the capital region projects. Thirdly, prepaid sale system and the guarantee system depending on construction companies dilute the regional differences in project finance in case of residential real estate projects. Although these systems contributed rapid growth of project finance, they may be the main factors distorting project finance market which lead to financial crisis. In these context, policy implications may be derived in order to solve the confronted problems of project finance market.

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Increasing Profitability of the Halal Cosmetics Industry using Configuration Modelling based on Indonesian and Malaysian Markets

  • Dalir, Sara;Olya, Hossein GT;Al-Ansi, Amr;Rahim, Alina Abdul;Lee, Hee-Yul
    • Journal of Korea Trade
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    • v.24 no.8
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    • pp.81-100
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    • 2020
  • Purpose - Based on complexity theory, this study develops a configurational model to predict the profitability of Halal cosmetics firms in the Indonesian and Malaysian markets. The proposed research model involves two level configurations-industry context and selling strategies-to predict high and low scores of a firm's profitability. The industry context configuration model comprises industry stability, product homogeneity, price sensitivity, and switching cost. Selling strategies include customer-focused, competitor-focused, and margin-focused approaches. Design/methodology - This is the first empirical study that calculates causal models using a combination of industry context and selling strategy factors to predict profitability. Data obtained from the marketing managers of cosmetics firms are used to test the proposed configurational model using fuzzy-set qualitative comparative analysis (fsQCA). It contributes to the current knowledge of business marketing by identifying the factors necessary to achieve profitability using analysis of condition (ANC). Findings - The results revealed that unique and distinct models explain the conditions for high and low profitability in the Indonesian and Malaysian halal cosmetic markets. While customer-focused selling strategy is necessary to attain a higher profit in both the markets, margin-focused selling strategy appears to be an essential factor only in Malaysia. Complexity of the interactions of selling strategies with industry factors and differences between across two study markets confirmed that complexity theory can support the research configurational model. The theoretical and practical implications are also illustrated. Originality/value - Despite the rapid growth of the global halal industry, there is little knowledge about the halal cosmetic market. This study contributes to the current literature of the halal market by performing a set of asymmetric analytical approaches using a complex theoretical model. It also deepens our understating of how the Korean firms can approach the Muslim consumer's needs to generate more beneficial turnover/revenue.

Injection of an Intermediate Fluid into a Rotating Cylindrical Container Filled with Two-layered Fluid

  • Na, Jung-Yul;Hwang, Byong-Jun
    • Journal of the korean society of oceanography
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    • v.31 no.4
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    • pp.173-182
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    • 1996
  • A median-density fluid was injected into the upper layer of a two-layered fluid in a rotating cylindrical container. Several sets of the top and bottom boundary configurations were employed and the flow pattern of each layer including the injected fluid was observed to determine the factors that affect the path of the injected intermediate fluid. The axisymmetric path of the intermediate fluid when the upper layer had a free surface, changed into the asymmetric path with bulged-shape radial spreading whenever either the upper layer or the lower layer had ${\beta}$-effect. The internal Fronds number that controls the shape of the interface turned out to be the most important parameter that determines the radial spreading in terms of location and strength. When the upper and lower layer had the ${\beta}$-effect, convective overturning produced anticyclonic vortices at the frontal edge of the intermediate fluid, and that could enhance the vertical mixing of different density fluids. The intermediate fluid did not produce any topographic effect on the upper-layer motion during its spreading over the interface, since its thickness was very small. However, its anticyclonic motion within the bulged-shape produced a cyclonic motion in the lower layer just beneath the bulge.

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