• Title/Summary/Keyword: Power asymmetry

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Partial Discharge Diagnosis of Interface Defect by the Distribution Statistical Analysis (분포 통계 해석에 의한 계면 결함 부분방전 진단)

  • Cho, Kyung-Soon;Lee, Kang-Won;Kim, Won-Jong;Hong, Jin-Woong;Shin, Jong-Yeol
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.4
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    • pp.348-353
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    • 2008
  • Most of the high voltage insulation systems, such as the power cable joint having hetero interface, are composed of more than two different insulators to improve insulating performance. The partial discharge(PD) in these hetero interface is expected to affect the total insulation performance. Thus, it is important to study electrical properties on these interfaces. This study described the influence of copper and semiconductive substance defects on $\Phi$-q-n distribution between the interface of the model cable joints to classify PD source. PD was sequentially detected for 600 cycles of the applied voltage. The K-means cluster analysis has been analyzed to investigate the $\Phi$-q-n distribution. The skewness-kurtosis(Sk-Ku) plot from K-means clustering results was defined to quantify cluster distribution and classify distribution patterns. The Sk-Ku plot is composed of skewness and kurtosis along abscissa and ordinate which indicate the asymmetry and the sharpness of distribution. As a result of the Sk-Ku plot, it was confirmed that the data was distributed in 1st 2nd and 3rd quadrant at copper foreign substance defect, but in case of semiconductive foreign substance, the data was distributed in 2nd quadrant only.

Korean Expatriates Adjustments and Job Satisfaction in Malaysia: Analysis of Corporate Cultural Asymmetry

  • Dastane, Omkar;Lee, Woo Yong Willis
    • The Journal of Industrial Distribution & Business
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    • v.7 no.4
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    • pp.33-45
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    • 2016
  • Purpose - The purpose of this study is to discover how Korean expatriates that are currently employed in Korean subsidiaries operational in Malaysia possibly suffer from career dissatisfaction due to differences between Korean Corporate Culture (KCC) and Malaysian Corporate Culture (MCC). The integration of KCC into MCC is discussed. Research design, data, and methodology - The analysis herein is via a qualitative research. Forty-six interviewees voluntarily participated in in-depth interviews. Document analysis and qualitative interviews were utilized to develop participant profiles and to generate the framework. Interview data were transcribed and subsequently analysed to facilitate the development of themes and ultimately led to emerging patterns. The framework discusses the following Confucian pillars pronounced in KCC: Control Systems, Power Structures, Organisational Structures, Authority and Harmony and Stories and Myths. Those pillars are analysed and the results of the interviews are discussed in detail. Results - Korean expatriates on assignment in Malaysia endure struggles in all five selected Confucian pillars as they are not symmetrical with Korean Corporate Culture common at head companies in Korea. Conclusion - As a consequence, there is substantial disharmony which needs to be rectified if Korean companies are to continue their 'miraculous' economic movement into the country.

Infrastructure for Network Applications based on Multi-Platform (멀티 플랫폼 기반 네트워크 응용을 위한 기반 구조)

  • 김진덕;진교홍
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.11a
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    • pp.677-681
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    • 2002
  • Several multi-user online applications which are operated by the existing fixed terminals(PC) are being changed into online application based on multi-platform operated by the several PC, PDA and mobile phones to perform concurrent works due to the popularization of mobile devices recently. This paper proposed the infrastructure for network applications based on multi-platform. We also proposed the methods of consistency control based on multi-platform, update propagation protocols among diverse clients which take the asymmetry of computing power and network bandwidth among each client into account. Moreover, we implemented a chatting application based on multi-platform and it showed the proposed infrastructure and methods perform well.

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Strategic Choices of Small States in Asymmetric Dependence: Myanmar - China Relations through the case of the Myitsone Dam

  • Eszterhai, Viktor;Thida, Hnin Mya
    • Journal of Contemporary Eastern Asia
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    • v.20 no.2
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    • pp.157-173
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    • 2021
  • In the transition to a multipolar international system, the literature has focused on great power competition while little attention has been given to the strategic possibilities of smaller states. However, as a result of globalization, states are so closely interconnected that the primary strategies of even major powers are not to achieve zero-sum solutions but to create asymmetric dependency through which they can influence the behavior of other states and non-state actors. States are assisted in this effort by a variety of tools, including setting up institutions, direct economic influence and through building different forms of infrastructure connectivity networks. By discussing asymmetric dependency situations from the perspective of the great powers, the literature presents smaller states primarily as passive actors, paralyzed by their dependence on great powers. Our paper argues that interdependence allows smaller states to effectively influence larger actors and examines strategies from which smaller states can choose in order to influence the behavior of larger states. Despite an extremely asymmetric relationship between Myanmar and China, actors in Myanmar have sought to influence China's Myanmar policy. We examine a case study of the Myitsone Dam, including Myanmar's strategic aims, chosen strategy and limitations in maneuvering space. Semi-structured interviews with local decision-makers and stakeholders are conducted in order to portray the full picture. Our study concludes that further research on the influencing strategies of small states in response to asymmetric dependence can contribute to a better understanding of the interdependence of states.

Influence of trailing edge serration in the wake characteristics of S809 airfoil

  • Mano Sekar;Amjad Ali Pasha;Nadaraja Pillai Subramania
    • Wind and Structures
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    • v.37 no.1
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    • pp.15-23
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    • 2023
  • The wake behavior of extended flat plate and serration in the trailing edge of S809 airfoil is presented in this experimental study using wind tunnel testing. The clustering of wind turbines in wind parks has recently been a pressing issue, due to the expected increase in power output and deciding the number of wind turbines to be installed. One of the prominent factors which influence the performance of the subsequent wind turbines is the downstream wake characteristics. A series of wind tunnel investigations were performed to assess the downstream near wake characteristics of the S809 airfoil at various angles of attack corresponding to the Reynolds Number Re = 2.02 × 105. These experimental results revealed the complex nature of the downstream near wake characteristics featuring substantial asymmetry arising out of the incoherent flow separations prevailing over the suction and the pressure sides of the airfoil. Based on the experimental results, it is found that the wake width and the downstream velocity ratio decrease with an increase in the angle of attack. Nonetheless, the dissipation length and downstream velocity ratio increases proportionally in the downstream direction. Additionally, attempts were made to understand the physical nature of the near wake characteristics at 1C, 2C, 3C and 4C downstream locations.

The Flexible Design of 0.96 Tbps WDM System over 1,000km NZ-DSF by Using Optimal Parameters of Optical Phase Conjugator (광 위상 공액기의 최적 파라미터를 이용한 1,000km NZ-DSF를 갖는 0.96 Tbps WDM 시스템의 유연한 설계)

  • Lee, Seong-Real;Doh, Kyu-Bong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.7A
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    • pp.657-665
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    • 2007
  • In this paper, it is investigated that the limitation due to the asymmetry of optical power and chromatic dispersion with respect to optical phase conjugator (OPC) for compensating optical signal distortion of WDM channels in mid-span spectral inversion (MSSI) technique is overcame by using OPC position offset and optimal dispersion coefficients of fiber sections, which depend on OPC position offset. It is confirmed that overall WDM channels are efficiently compensated by applying the optimal parameter values obtained from the proposed method into 24 channels ${\times}\;40\;Gbps$ WDM system with non zero - dispersion shifted fiber (NZ-DSF) of 1,000 km, such as power penalties of inter-channel are reduce to almost 3.5 dB from the infinite value. It is also confirmed that the flexible design of WDM system with OPC is possible by using the optimal parameters, in which OPC is placed at ${\pm}15\;km$ from 500 km for efficiently compensating overall channels.

Factors Affecting the Insured Organizations Participation in Decision Making Process in Health Insurance Policy Committee (건강보험정책심의위원회 가입자 단체의 의사결정 참여에 영향을 미치는 요인)

  • Han, Joo-Sung;Kim, Chang-Yup
    • Health Policy and Management
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    • v.27 no.4
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    • pp.336-346
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    • 2017
  • Background: Due to the asymmetry of information and knowledge and the power of bureaucrats and medical professionals, it is not easy for citizens to participate in health care policy making. This study analyzes the case of the insured organization participating in the Health Insurance Policy Committee (HIPC) and provides a basis for discussing methods and conditions for better public participation. Methods: Qualitative analysis was conducted using the in-depth interviews with the participants and document data such as materials for HIPC meetings. Semi-structured interviews were conducted with purposively sampled six participants from organizations representing the insured in HIPC. The meanings related to the factors affecting participation were found and categorized into major categories. Results: The main factors affecting participating in the decision making process were trust and cooperation among the participants, structure and procedure of governance, representation and expertise of participants, and contents of issues. Due to limited cooperation, participants lacked influence in important decisions. There was an imbalance in power due to unreasonable procedures and criteria for governance. As the materials for meetings were provided inappropriate manner, it was difficult for participants to understand the contents and comments on the meeting. Due to weak accountability structure, opinions from external stakeholders have not been well received. The participation was made depending on the expertise of individual members. The degree of influence was different depending on the contents of the issues. Conclusion: In order to meet the values of democracy and realize the participation that the insured can demonstrate influence, it is necessary to have a fair and reasonable procedure and a sufficient learning environment. More deliberative structure which reflects citizen's public perspective is required, rather than current negotiating structure of HIPC.

A Study on Deception Ship for Ship Susceptibility Improvement based on System Engineering Approach (함정 피격성 향상을 위한 시스템엔지니어링 접근법 기반의 기만선박 개념 연구)

  • Kang, Hee-Jin;Shin, Jong-Gye;Lee, Dong-Kon;Choi, Jin
    • Journal of the Society of Naval Architects of Korea
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    • v.46 no.3
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    • pp.313-314
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    • 2009
  • To project military power, the paradigm of the modern warship aquisition has evolved with more large platform and high-technology equipment. For example, the Aegis combat system equipped warship is one of the most advanced and capable defense systems currently in use. Concurrently, if the warship attacked and disabled, it may worse the asymmetry of the battle field and it also depress the morale of the fleet. For that reason, to keep and protect few number of the big and high technology equipped warship from enemy is very important. At the present, the performance of unit weapon has enhanced remarkably. A Korean-built SS-209 class submarine, Lee Chun-ham, participated in Naval Exercise Tandem Thrust conducted in 1999, sink the target ship ex-USS Oklahoma by a single torpedo. USS Stark was struck on May 17, 1987, by two Exocet anti ship missiles and disabled. For this reason, susceptibility should be prior to vulnerability and recoverability. In this paper, deception ship which is small and chief but has very similar signatures to large and high technology equiped warship has conceptually studied by using systems engineering approach. And it may be a effective way to enhance the susceptibility of the key fighting power.

Application of Multiple Parks Vector Approach for Detection of Multiple Faults in Induction Motors

  • Vilhekar, Tushar G.;Ballal, Makarand S.;Suryawanshi, Hiralal M.
    • Journal of Power Electronics
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    • v.17 no.4
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    • pp.972-982
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    • 2017
  • The Park's vector of stator current is a popular technique for the detection of induction motor faults. While the detection of the faulty condition using the Park's vector technique is easy, the classification of different types of faults is intricate. This problem is overcome by the Multiple Park's Vector (MPV) approach proposed in this paper. In this technique, the characteristic fault frequency component (CFFC) of stator winding faults, rotor winding faults, unbalanced voltage and bearing faults are extracted from three phase stator currents. Due to constructional asymmetry, under the healthy condition these characteristic fault frequency components are unbalanced. In order to balanced them, a correction factor is added to the characteristic fault frequency components of three phase stator currents. Therefore, the Park's vector pattern under the healthy condition is circular in shape. This pattern is considered as a reference pattern under the healthy condition. According to the fault condition, the amplitude and phase of characteristic faults frequency components changes. Thus, the pattern of the Park's vector changes. By monitoring the variation in multiple Park's vector patterns, the type of fault and its severity level is identified. In the proposed technique, the diagnosis of faults is immune to the effects of unbalanced voltage and multiple faults. This technique is verified on a 7.5 hp three phase wound rotor induction motor (WRIM). The experimental analysis is verified by simulation results.

Debt Issuance and Capacity of Korean Retail Firms (유통 상장기업들의 부채변화에 관한 연구)

  • Lee, Jeong-Hwan;Son, Sam-Ho
    • Journal of Distribution Science
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    • v.13 no.9
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    • pp.47-57
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    • 2015
  • Purpose - The aim of this paper is to investigate the explanatory power of the Pecking-order theory (the cost of financing increases with asymmetric information) among Korean retail firms from the perspective of debt capacity. According to the Pecking-order theory, a firm's first preference is to use internal funds for its capital needs, its next preference is the issuance of debt, and its last preference is the issuance of equity; this is due to the information asymmetry problem between existing shareholders and investors. However, prior empirical studies, such as Lemmon and Zender (2010), argue that the entire sample test for the Pecking-order theory could be misleading due to the different levels of debt issuance capability of each of the individual firms; in fact, they confirm that the explanatory power of the Pecking-order theory improves after taking into account the differences in debt capacity of the U.S. firms they examined. This paper implements a case study approach among Korean retail firms to examine the relationship between debt capacity and the explanatory power of the Pecking-order theory in Korea. Research design, data, and methodology - This study uses the sample of public retail firms on the Korea Composite Stock Price Index (KOSPI) from the time period of 1990 to 2013. We gather related financial and accounting statements from the financial information firm WISEfn. Credit rating information is provided by the Korea Investor Service. We employ the models of Lemmon and Zender (2010) and Son and Kim (2013) to measure a firm's debt capacity. Their logit models use the rating dummy variable as a dependent variable and incorporate other firm characteristics as independent variables to estimate debt capacity. To test the Pecking-order theory, we adopt variants of the financing deficit model of Shyam-Sunder and Myers (1999). In the test of the Pecking-order theory, we consider all of the changes in total debt obligations, current debt obligations, and long-term debt obligations. Results - Our main contribution to the literature is our confirmation of the predicted relationship between debt capacity and the explanatory power of the Pecking-order theory among Korean retail firms. The coefficients on financing deficits become greater as a firm's debt capacity improves. This is consistent with the results of Lemmon and Zender (2010). The coefficients on the square of the financing deficits are also negative for the firms in the largest debt capacity group, which is also consistent with the predictions in prior literature. Conclusions - This study takes a case study approach by examining Korean retail firms. We confirm that the Pecking-order theory explains the capital structure of retail firms more appropriately, after taking into account the debt capacity of each firm. This result suggests the importance of debt capacity consideration in the testing of the Pecking-order theory. Our result also implies that there has been a potential underestimation of the explanatory power of the Pecking-order theory in existing studies.