• Title/Summary/Keyword: Small world theory

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Structural Design and Analysis for Small Wind Turbine Blade (초소형 풍력발전용 블레이드에 대한 구조설계 몇 해석)

  • Lee, Seung-Pyo;Kang, Ki-Weon;Chang, Se-Myong;Lee, Jang-Ho
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.2
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    • pp.288-294
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    • 2010
  • In recent years, wind energy has been the world's fastest growing source of energy. This paper describes the structural design and analysis of composite blade for 2 kW-level HAWT (horizontal axis wind turbine). The aerodynamic design and force, which are required to design and analyze a composite blade structurally, are calculated through BEMT(blade element momentum theory) implemented in public code PROPID. To obtain the equivalent material properties of filament wound composite blades, the rule-of-mixture is applied using the basic material properties of fiber and matrix, respectively. Lay-up sequence, ply thickness and ply angle are designed to satisfy the loading conditions. Structural analysis by using commercial software ABAQUS is performed to compute the displacement and strength ratio of filament wound composite blades.

Topological and Statistical Analysis for the High-Voltage Transmission Networks in the Korean Power Grid

  • Kang, Seok-Gu;Yoon, Sung-Guk
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.42 no.4
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    • pp.923-931
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    • 2017
  • A power grid is one of the most complex networks and is critical infrastructure for society. To understand the characteristics of a power grid, complex network analysis has been used from the early 2000s mainly for US and European power grids. However, since the power grids of different countries might have different structures, the Korean power grid needs to be examined through complex network analysis. This paper performs the analysis for the Korean power grid, especially for high-voltage transmission networks. In addition, statistical and small-world characteristics for the Korean power grid are analyzed. Generally, the Korean power grid has similar characteristics to other power grids, but some characteristics differ because the Korean power grid is concentrated in the capital area.

Particle Swarm Optimization based Haptic Localization of Plates with Electrostatic Vibration Actuators

  • Gwanghyun Jo;Tae-Heon Yang;Seong-Yoon Shin
    • Journal of information and communication convergence engineering
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    • v.22 no.2
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    • pp.127-132
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    • 2024
  • Haptic actuators for large display panels play an important role in bridging the gap between the digital and physical world by generating interactive feedback for users. However, the generation of meaningful haptic feedback is challenging for large display panels. There are dead zones with low haptic sensations when a small number of actuators are applied. In contrast, it is important to control the traveling wave generated by the actuators in the presence of multiple actuators. In this study, we propose a particle swarm optimization (PSO)-based algorithm for the haptic localization of plates with electrostatic vibration actuators. We modeled the transverse displacement of a plate under the effect of actuators by employing the Kirchhoff-Love plate theory. In addition, starting with twenty randomly generated particles containing the actuator parameters, we searched for the optimal actuator parameters using a stochastic process to yield localization. The capability of the proposed PSO algorithm is reported and the transverse displacement has a high magnitude only in the targeted region.

A Study on the Refusal of National Examination for Medical Students: Focusing on the Signaling Game Theory (의과대학생 국가시험 거부 사태에 대한 고찰: 신호게임 이론을 중심으로)

  • Hyeon, Seung Hyo;Kim, Da Young;Lee, Min Kyu
    • Health Policy and Management
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    • v.31 no.4
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    • pp.479-490
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    • 2021
  • Background: Conflict in the medical world in 2020 led to the rejection of the national examination for doctors. This study explained the process until the end of the national test refusal situation triggered in 2020 through the signaling game theory. The government has succeeded in requiring medical students to take the national exam. Methods: To explain the rejection of the national examination, we first compose and show an example of two small non-signaling games where medical students know which type the government is of, then combine them to play a signaling game. Results: The behavior of the government and medical students was examined through the signaling game model. In the context of the coronavirus disease 2019 (COVID-19) pandemic, the government makes an ultimatum, whatever the type. And the medical students accept it. They judged that the government could not be expected to abolish the policy. If COVID-19 had not occurred, medical students would have been able to continue the confrontation. Conclusion: The government instilled in the other party the perception that the government would not bend its policies because it was the surly type and would not be afraid of a strong confrontation. Through the image created in this way, the government was forced to accept the ultimatum by medical students. Academically, this study is to deal with the policy-making process through the signaling game theory. In the area of health care policy, this study suggests that various situations such as the type of government or the spread of COVID-19 can become important in addition to the rationality of the policy itself.

A Theory on the Scope of Financial Activity (금융(金融)의 전업(專業) 및 겸업화(兼業化) 이론(理論): 금융산업조직론(金融産業組織論)의 모색(摸索))

  • Jwa, Sung-hee
    • KDI Journal of Economic Policy
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    • v.13 no.1
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    • pp.167-197
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    • 1991
  • This paper is intended as an introductory essay to explain endogenous changes in the scope of firm activities in the competitive structure of a deregulated, multi-product financial industry. Recently, the global financial industry has been experiencing a widespread reshuffling in its activities, reflecting both consolidation and specialization. The spread of the universal banking system, which involves the integration of various kinds of financial activities, has resulted in the so-called financial supermarket. At the same time, the traditional set of banking activities has been unbundled into so-called financial boutiques. A relevant question is where the current reshuffling process of integration and disintegration in financial activities might lead the financial industry. However, presently popular theories of the financial industry are not really appropriate for the analysis of this issue. This paper attempts to integrate the theory of specialization [George J. Stigler, "The Division of Labor is Limited by the Extent of the Market," Journal of Political Economy, Vol. LIX, No.3, June 1951] and the theory of the multi-product firm [William J. Baumol, John C. Panzar, and Robert D. Willig, Contestable Markets and the Theory of Industry Structure, Harcourt Brace Jovanovich, Inc., New York, 1982] and to apply the resulting hybrid theory, a theory on the scope of financial activity, to the financial industry. The implications of this theory for the issues raised above are formalized under five hypotheses on the reshuffling of financial activities as listed below: Hypothesis I: The differences in the organization of financial industries among countries are determined by differences in the size of the financial markets, other things being equal. Hypothesis II: A financial firm will separate those financial activities simultaneously having relatively strong economies of scale and relatively weak economies of scope (alternatively, diseconomies of scope) from other activities. Conversely, the firm will integrate those activities simultaneously having relatively weak economies of scale (alternatively, diseconomies of scale) and relatively strong economies of scope with incumbent activities. Hypothesis III: A competitive equilibrium in the deregulated financial industry will consist of both specialized and multi-product financial firms, resulting in a mixed form of specialized and universal banking systems. Hypothesis IV: As world financial markets fully integrate and all countries consequently face this single, common world market, the financial structures of individual countries will become increasingly similar. Hypothesis V: A more universal banking system will dominate the deregulated financial industry in countries with relatively small financial markets, while a more specialized banking system will dominate in countries with relatively large financial markets. However, equilibrium will ultimately be mixed, with specialized and universal banks coexisting, as stated in Hypothesis III. Based on these hypotheses, this paper interprets the historical development of specialized vs. universal banking systems in major industrial countries as a process driven by the evolution of the financial market in each country - i.e. the change in the size of the financial market over time. In addition, this paper anticipates that the final equilibrium of the world financial industry, which is currently under the pressure of financial innovations and deregulation, will be a mixed equilibrium with both specialized boutiques and universal supermarket-type financial firms, instead of an exclusively specialized or universal banking system. Future research should seek continued theoretical elaboration and empirical verification of this paper's hypotheses.

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Small Business Innovation Research Program in the United States: A Political Review and Implications for East Asian Countries

  • Ryu, Youngbok
    • STI Policy Review
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    • v.6 no.2
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    • pp.54-86
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    • 2015
  • The study examines the U.S. Small Business Innovation Research (SBIR) program, with a focus on the recent Reauthorization, and compares, in the political context, the U.S. and East Asian countries-Japan, Korea and Taiwan-that adopted the U.S. SBIR program. For the systematic analysis and cross-country comparison, the study employs Kingdon (2003)'s framework-his political theory and Garbage Can Model-to identify political participants and processes underlying the SBIR Reauthorization and to analyze the differences in problem, policy, and politics streams between the U.S. and East Asian countries. For the cross-country comparison, specifically, the study uses various data sources such as OECD, Global Entrepreneurship Monitor, Hofstede's Cultural Dimensions, and World Value Survey. Based on the analysis outcomes, implications of U.S. practices on East Asian countries are extracted as follows. East Asian countries tend to: Have higher entrepreneurial aspiration while lower entrepreneurial activity and attitude than the U.S.; bear higher long term orientation and uncertainty avoidance while lower individualism than the U.S.; and have greater expectations of technology development and higher confidence in political parties while participating less in political action than the U.S. Drawing on the differences, the following policy recommendations are suggested. East Asian countries should: Improve entrepreneurs' access to resources (in particular, financial resource) in order to link their high entrepreneurial aspiration to actual entrepreneurial activities; cultivate failure-tolerating culture and risk-taking entrepreneurs, for instance, by providing a second chance to SBIR-participating businesses that failed to materialize their innovative ideas; and leverage their high expectations of new technology in order to take bold actions regarding their SBIR programs, and update the programs by drawing out constructive dialogues between SBIR stakeholders.

A Study on the European Symbolist Costume -Focusing on Gustav klimt's Art World- (유럽 상징주의 복식에 관한 연구 -구스타브 클림트(Gustav Klimt)의 회화 세계를 중심으로-)

  • 양숙희
    • Journal of the Korean Society of Costume
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    • v.22
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    • pp.277-296
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    • 1994
  • The progressive artists in Austria including Gustav Klimt organized the Viennes Se-cessionist in 1897 and they took an active part in the reformation of the reformation of the applied art by accepting the Jugendstil standing for the true art. The vocabularies which characterize this group are decoration literature and the power of symbol. Klimt especially expressed these characteristics and his strong person-ality. For he created his works with the sym-bolic and friendly splendor through his highly decorative talents by accepting the enwly changed artistic situation in those days and by getting out of the naturalistic trends he was regarded as an avant-garde artist as a major figure among the Symbolist artists who revived European culture which was destroyed through the World War I. The characteristics of klimt's works was to express the various human thoughts and minds through the decorativeness and the femininity and to use the decorative elements of old Greek and Egyptian culture and Japanese art as the motives of his works, His art is to be found between the naturalistic characteristics and formalization as well as between the in-dustrial arts and the fine arts. In his many portraits he preferred women by trying to express eroticism hidden behind the human inner world. For this he demonstrated the attractiveness and the characteristics of the models by designing the illusionary and unique clothes. In general his genius was to be seen through the costume which was decorated with metals and jewels and through the characteristics of the modern costume in which the previous solid silhouette was removed and the gentle and elegant me-dium color was used. by accepting the new artistic trends in the turn of the century by fully expressing those characteristics in his creative world and by taking his theme from the eroticism through the decorativeness and the expression of women Gustav Klimt's uniquely decorative ex-pression completely realized the aesthetics of Jugendstil symbol decoration and expression which displayed not only the external appear-ance but also the inner world. Especially he created a new appearance emphasizing the costume of the characters in his works. Also through the costume he expressed his artistic consciousness and psy-chology. He showed the characteristics of the reformed costume through the medium color the simple forms and gentle silhouette. Also he tried to symbolize the passionate inner pow-er by designing the small mosaics such as the geometrical patterns whirlpool patterns and the indecent meanings all over the costume. Klmt's this kinds of attemps shows a Stil Kostume as the external outcome of the inner spiritual activities like art and it establishes a basis for the theory of costume are which deals with the concepts of costume from the artistics points of view. This tradition playing an important role in the contemporary history of costume even has been still inherited up to today.

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A Study on the Apparels of Shamanism during Cho Sun Dynasty (조선시대 무속복식연구-좌당 내력을 중심으로-)

  • 조효순
    • Journal of the Korean Society of Costume
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    • v.34
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    • pp.195-208
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    • 1997
  • 1) The color of JOGORI and CHIMA was such gorgeous and those garments were put on during the events of GAM-EUNG-CHUNG-BAI HO-GU-GEO-RI JO-SANG-GEO-RI DEWT-JUN and CHAN-BOO-GEO-RI. 2)BULSA-JANG-SAM(JE-SUK-GEO-RI) was white colored and had wide sleeves putting on a pink priestrobe and a pink belt on it 3) they put on HONG-CHUL-NIK(GU-REUNG) and CHONG-CHUL-NIK(DAE-GEO-RI). 4)They put on GOO-GUN-BOK(JUN-RIP JUN-BOK(BYUL-SUNG-GEO-RI) DONG-DA-RI(Expel the demon) 5) MONG-DOO-RI(MAN-SIN-MAL-BYUNG) put on the garment constructed with the color and from of a white straight collar a wide sleeve and a pink belt 6) A long robe was colored with green (GAM-EUNG-CHUNG-BAI) and was used not as a headdress but as a man's overcoat. 7) CHANG-EUI was a green colored small CHAHG-EUI(SUNG-JO-GEO-RI). As observed above the Shaman apprel during Chosun Dynasty is a part of the traditional clothing originated from THE THEORY OF THE COSMIC DUAL FORCES and THEORY OF THE COSMIC DUAL FORCES and the FIVE ELEMENTS (i.e. metal wood water fire and earth) It's basic form and wearing method were not so different from the traditional clothing silmilar to the official uniform during Chosun Dynasty and the official uniform was the symbol of authority(almost almighty) at that time of period and to that the Shaman apparel was constructed with the more gorgeous colors to emphasize the sanctity or the descent of the Divine Being from heaven. We realized that a Shaman had put on the symbolic garment suitable for the grade and nature of the Divine Body at every events to enter into " The World of Gods"Gods."

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Predicting Discharge Rate of After-care patient using Hierarchy Analysis

  • Jung, Yong Gyu;Kim, Hee-Wan;Kang, Min Soo
    • International Journal of Advanced Culture Technology
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    • v.4 no.2
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    • pp.38-42
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    • 2016
  • In the growing data saturated world, the question of "whether data can be used" has shifted to "can it be utilized effectively?" More data is being generated and utilized than ever before. As the collection of data increases, data mining techniques also must become more and more accurate. Thus, to ensure this data is effectively utilized, the analysis of the data must be efficient. Interpretation of results from the analysis of the data set presented, have their own on the basis it is possible to obtain the desired data. In the data mining method a decision tree, clustering, there is such a relationship has not yet been fully developed algorithm actually still impact of various factors. In this experiment, the classification method of data mining techniques is used with easy decision tree. Also, it is used special technology of one R and J48 classification technique in the decision tree. After selecting a rule that a small error in the "one rule" in one R classification, to create one of the rules of the prediction data, it is simple and accurate classification algorithm. To create a rule for the prediction, we make up a frequency table of each prediction of the goal. This is then displayed by creating rules with one R, state-of-the-art, classification algorithm while creating a simple rule to be interpreted by the researcher. While the following can be correctly classified the pattern specified in the classification J48, using the concept of a simple decision tree information theory for configuring information theory. To compare the one R algorithm, it can be analyzed error rate and accuracy. One R and J48 are generally frequently used two classifications${\ldots}$

Spread of Negative Word-of-mouth of Manufacturing Companies Via Twitter: From the Supply Chain Risk's Perspective (트위터를 통한 제조 기업의 부정적 구전 확산: 공급사슬 리스크 관점에서)

  • Jeong, EuiBeom;Yoo, Hanna
    • Journal of Korea Society of Industrial Information Systems
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    • v.26 no.5
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    • pp.79-94
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    • 2021
  • Despite the importance of the supply chain risk due to the negative word-of-mouth (NWOM) in social media, related research is insufficient. Thus, this study analyzes how the NWOM of the product is distributed through social media and the characteristics of the distributor based on social exchange theory. For this purpose, we collected information on car recalls from four companies using Twitter from the National Highway Traffic Safety Administration (NHTSA). Based on the Seed Tweet, a Re-Tweet (RT) network was constructed to examine the distribution and spread of NWOM, and regression analysis was performed to test the hypothesis. As a result, it was confirmed that NWOM is a small world network structure that spreads around hub users connected to many users. Moreover, it was found that the more interactive and reciprocal relations the first distributor has, the greater the speed and scale of distribution of NWOM.