• Title/Summary/Keyword: aspect ration

Search Result 47, Processing Time 0.02 seconds

Adaptive Control of Super Peer Ration using Particle Swarm Optimization in Self-Organizing Super Peer Ring Search Scheme (자기 조직적 우수 피어 링 검색기법에서 입자 군집 최적화(PSO)를 이용한 적응적 우수 피어 비율 조절 기법)

  • Jang, Hyung-Gun;Han, Sae-Young;Park, Sung-Yong
    • The KIPS Transactions:PartA
    • /
    • v.13A no.6 s.103
    • /
    • pp.501-510
    • /
    • 2006
  • The self-organizing super peer ring P2P search scheme improves search performance of the existing unstructured peer-to-peer systems, in which super peers with high capacity constitute a ring structure and all peer in the system utilize the ring for publishing or querying their keys. In this paper, we further improves the performance of the self-organizing ring by adaptively changing its super peer ratio according to the status of the entire system. By using PSO, the optimized super peer ratio can be maintained within the system. Through simulations, we show that our self-organizing super peer ring optimized by PSO outperforms not only the fixed super peer ring but also the self-organizing super ring with fixed ratio in the aspect of query success rate.

A study on combustion instability of solid rocket motor with cylinder-slot grain (실린더-슬롯형 그레인을 가진 고체로켓모터의 연소불안정 연구)

  • Lee, Dohyung;Kim, Hongjip
    • The Journal of the Acoustical Society of Korea
    • /
    • v.39 no.4
    • /
    • pp.371-377
    • /
    • 2020
  • Combustion instability occurred in the combustion test of solid rocket motor with large aspect ration Length/Diameter (L/D) and cylinder-slot grain. As a result of spectral analysis of the pressure perturbation, it was confirmed that the central axis longitudinal frequency was dominant, so that the length of the cylinder part was increased to eliminate the coincidence with acoustic node. In addition, acoustic modal analysis and flow analysis were performed to analyze the cause of instability by unsteady flow structure in solid rocket motors. It was confirmed that the combustion instability is reduced by quantitative comparison of the amplitude and frequencies of the pressure inside the combustion chamber using the grain shape before and after the design change. Finally, a combustion test was performed to verify that the combustion instability was resolved as in the flow analysis.

Image Processing Software Development for Detection of Oyster Hinge Lines (굴의 힌지 선 감지를 위한 영상처리 소프트웨어의 개발)

  • So, J.D.;Wheaton, Fred W.
    • Journal of Biosystems Engineering
    • /
    • v.22 no.2
    • /
    • pp.237-246
    • /
    • 1997
  • Shucking(removing the meat from the shell) an oyster requires that the muscle attachments to the two shell valves and the hinge be severed. Described here is the computer vision software needed to locate the oyster hinge line so it can be automatically severed, one step in development of an automated oyster shucker. Oysters are first prepared by washing and trimming off a small shell piece on the oyster hinge end to provide access to the outer hinge surface. A computer vision system employing a color video comera then gabs an image of the hinge end of the oyster shell. This image is Processed by the computer using software. The software is a combination of commercially available and custom written routines that locate the oyster hinge. The software uses four feature variables, circularity, rectangularity, aspect-ration, and Euclidian distance, to distinguish the hinge object from other dark colored objects on the hinge end of the oyster. Several techniques, including shrink-expand, thresholding, and others, were used to secure an image that could be reliably and efficiently processed to locate the oyster hinge line.

  • PDF

Application of nonlocal elasticity theory for buckling analysis of nano-scale plates (나노 스케일 판의 좌굴해석을 위한 비국소 탄성 이론의 적용)

  • Lee, Won-Hong;Han, Sung-Cheon;Park, Weon-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.13 no.11
    • /
    • pp.5542-5550
    • /
    • 2012
  • Third-order shear deformation theory is reformulated using the nonlocal elasticity of Eringen. The equation of equilibrium of the nonlocal elasticity are derived. This theory has ability to capture the both small scale effects and quadratic variation of shear strain through the plate thickness. Navier's method has been used to solve the governing equations for all edges simply supported boundary conditions. Analytical solutions of buckling of nano-scale plates are presented using this theory to illustrate the effect of nonlocal theory on buckling load of the nano-scale plates. The relations between nonlocal third-order and local theories are discussed by numerical results. Further, effects of (i) length (ii) nonlocal parameter, (iii) aspect ratio and (iv) mode number on nondimensional buckling load are studied. In order to validate the present solutions, the reference solutions are used and discussed. The present results of nano-scale plates using the nonlocal theory can provide a useful benchmark to check the accuracy of related numerical solutions.

A Comparative Study of Ship Collision Legislation in Korea and China (한국과 중국의 선박충돌법제의 비교법적 연구)

  • Jiancuo, Qi
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.28 no.4
    • /
    • pp.577-586
    • /
    • 2022
  • The increasing trade volume between Korea and China has rapidly expanded the maritime transport between the two countries. However, safety, particularly considering the ship collisions in the Yellow Sea and East Sea waters, has not been fully ensured. These collision accidents in that region endanger traffic safety and the marine environment, moreover, it has the potential to cause legal complexity because Korea and China haver domestic legislation, that are considerably different in some aspects. International conventions and domestic legislation in China provide detailed laws with respect to ship collisions, however, the theory of ship collision infringement still needs to be improved, enriched, and developed. Because these laws are not very clear on the resolution of disputes resulting from ship collisions, we focused on the final judgments by the Supreme Court of China (SPC), and the judicial judgments set by the Maritime Court of China. This study aimed to explore the domestic legislation applicable to disputes related to ship collisions in China, and comparatively investigate the legal provisions of Korea and China on the issue of ship collisions, particularly on the aspect of damage compensation, fault ration, and liability apportionment.

Installation Art In Indonesian Contemporary Art; A Quest For Medium and Social Spaces (인도네시아 현대미술에 있어서의 설치미술 - 미디엄과 사회적 공간을 위한 탐색)

  • Kusmara, A. Rikrik
    • The Journal of Art Theory & Practice
    • /
    • no.5
    • /
    • pp.217-229
    • /
    • 2007
  • Many historical research and facet about modern art in Indonesia which formulating background of contemporary Indonesian Art. Indonesian art critic Sanento Yuliman states that Modern art has been rapidly developing in Indonesia since the Indonesian Independence in 1945. Modern Art is a part of the super culture of the Indonesian metropolitan and is closely related to the contact between the Indonesian and Western Cultures. Its birth was part of the nationalism project, when the Indonesian people consists of various ethnics were determined to become a new nation, the Indonesian nation, and they wished for a new culture, and therefore, a new art. The period 1960s, which was the beginning of the creation and development of the painters and the painters associations, was the first stage of the development of modern art in Indonesia. The second stage showed the important role of the higher education institutes for art. These institutes have developed since the 1950s and in the 1970s they were the main education institutes for painters and other artists. The artists awareness of the medium, forms or the organization of shapes were encouraged more intensely and these encouraged the exploring and experimental attitudes. Meanwhile, the information about the world's modern art, particularly Western Art; was widely and rapidly spread. The 1960s and 1970s were marked by the development of various abstractions and abstract art and the great number of explorations in various new media, like the experiment with collage, assemblage, mixed media. The works of the Neo Art Movement-group in the second half of the 1970s and in the 1980s shows environmental art and installations, influenced by the elements of popular art, from the commercial world and mass media, as well as the involvement of art in the social and environmental affairs. The issues about the environment, frequently launched by the intellectuals in the period of economic development starting in the 1970s, echoed among the artists, and they were widened in the social, art and cultural circles. The Indonesian economic development following the important change in the 1970s has caused a change in the life of the middle and upper class society, as has the change in various aspects of a big city, particularly Jakarta. The new genre emerged in 1975 which indicates contemporary art in Indonesia, when a group of young artists organized a movement, which was widely known as the Indonesian New Art Movement. This movement criticized international style, universalism and the long standing debate on an east-west-dichotomy. As far as the actual practice of the arts was concerned the movement criticized the domination of the art of painting and saw this as a sign of stagnation in Indonesian art development. Based on this criticism 'the movement' introduced ready-mades and installations (Jim Supangkat). Takes almost two decades that the New Art Movement activists were establishing Indonesian Installation art genre as contemporary paradigm and influenced the 1980's gene ration like, FX Harsono, Dadang Christanto, Arahmaiani, Tisna Sanjaya, Diyanto, Andarmanik, entering the 1990's decade as "rebellion period" ; reject towards established aesthetic mainstream i.e. painting, sculpture, graphic art which are insufficient to express "new language" and artistic needs especially to mediate social politic and cultural situation. Installation Art which contains open possibilities of creation become a vehicle for aesthetic establishment rejection and social politics stagnant expression in 1990s. Installation art accommodates two major field; first, the rejection of aesthetic establishment has a consequences an artists quest for medium; deconstruction models and cross disciplines into multi and intermedia i.e. performance, music, video etc. Second aspect is artists' social politic intention for changes, both conclude as characteristics of Indonesian Installation Art and establishing the freedom of expression in contemporary Indonesian Art until today.

  • PDF

A Study on the Born Global Venture Corporation's Characteristics and Performance ('본글로벌(born global)전략'을 추구하는 벤처기업의 특성과 성과에 관한 연구)

  • Kim, Hyung-Jun;Jung, Duk-Hwa
    • Journal of Global Scholars of Marketing Science
    • /
    • v.17 no.3
    • /
    • pp.39-59
    • /
    • 2007
  • The international involvement of a firm has been described as a gradual development process "a process in which the enterprise gradually increases its international involvement in many studies. This process evolves in the interplay between the development of knowledge about foreign markets and operations on one hand and increasing commitment of resources to foreign markets on the other." On the basis of Uppsala internationalization model, many studies strengthen strong theoretical and empirical support. According to the predictions of the classic stages theory, the internationalization process of firms have been recognized and characterized gradual evolution to foreign markets, so called stage theory: indirect & direct export, strategic alliance and foreign direct investment. However, termed "international new ventures" (McDougall, Shane, and Oviatt 1994), "born globals" (Knight 1997; Knight and Cavusgil 1996; Madsen and Servais 1997), "instant internationals" (Preece, Miles, and Baetz 1999), or "global startups" (Oviatt and McDougall 1994) have been used and come into spotlight in internationalization study of technology intensity venture companies. Recent researches focused on venture company have suggested the phenomenons of 'born global' firms as a contradiction to the stages theory. Especially the article by Oviatt and McDougall threw the spotlight on international entrepreneurs, on international new ventures, and on their importance in the globalising world economy. Since venture companies have, by definition. lack of economies of scale, lack of resources (financial and knowledge), and aversion to risk taking, they have a difficulty in expanding their market to abroad and pursue internalization gradually and step by step. However many venture companies have pursued 'Born Global Strategy', which is different from process strategy, because corporate's environment has been rapidly changing to globalization. The existing studies investigate that (1) why the ventures enter into overseas market in those early stage, even in infancy, (2) what make the different international strategy among ventures and the born global strategy is better to the infant ventures. However, as for venture's performance(growth and profitability), the existing results do not correspond each other. They also, don't include marketing strategy (differentiation, low price, market breadth and market pioneer) that is important factors in studying of BGV's performance. In this paper I aim to delineate the appearance of international new ventures and the phenomenons of venture companies' internationalization strategy. In order to verify research problems, I develop a resource-based model and marketing strategies for analyzing the effects of the born global venture firms. In this paper, I suggested 3 research problems. First, do the korean venture companies take some advantages in the aspects of corporate's performances (growth, profitability and overall market performances) when they pursue internationalization from inception? Second, do the korean BGV have firm specific assets (foreign experiences, foreign orientation, organizational absorptive capacity)? Third, What are the marketing strategies of korean BGV and is it different from others? Under these problems, I test then (1) whether the BGV that a firm started its internationalization activity almost from inception, has more intangible resources(foreign experience of corporate members, foreign orientation, technological competences and absorptive capacity) than any other venture firms(Non_BGV) and (2) also whether the BGV's marketing strategies-differentiation, low price, market diversification and preemption strategy are different from Non_BGV. Above all, the main purpose of this research is that results achieved by BGV are indeed better than those obtained by Non_BGV firms with respect to firm's growth rate and efficiency. To do this research, I surveyed venture companies located in Seoul and Deajeon in Korea during November to December, 2005. I gather the data from 200 venture companies and then selected 84 samples, which have been founded during 1999${\sim}$2000. To compare BGV's characteristics with those of Non_BGV, I also had to classify BGV by export intensity over 50% among five or six aged venture firms. Many other researches tried to classify BGV and Non_BGV, but there were various criterion as many as researchers studied on this topic. Some of them use time gap, which is time difference of establishment and it's first internationalization experience and others use export intensity, ration of export sales amount divided by total sales amount. Although using a mixed criterion of prior research in my case, I do think this kinds of criterion is subjective and arbitrary rather than objective, so I do mention my research has some critical limitation in the classification of BGV and Non_BGV. The first purpose of research is the test of difference of performance between BGV and Non_BGV. As a result of t-test, the research show that there are statistically efficient difference not only in the growth rate (sales growth rate compared to competitors and 3 years averaged sales growth rate) but also in general market performance of BGV. But in case of profitability performance, the hypothesis that is BGV is more profit (return on investment(ROI) compared to competitors and 3 years averaged ROI) than Non-BGV was not supported. From these results, this paper concludes that BGV grows rapidly and gets a high market performance (in aspect of market share and customer loyalty) but there is no profitability difference between BGV and Non_BGV. The second result is that BGV have more absorptive capacity especially, knowledge competence, and entrepreneur's international experience than Non_BGV. And this paper also found BGV search for product differentiation, exemption strategy and market diversification strategy while Non_BGV search for low price strategy. These results have never been dealt with other existing studies. This research has some limitations. First limitation is concerned about the definition of BGV, as I mentioned above. Conceptually speaking, BGV is defined as company pursue internationalization from inception, but in empirical study, it's very difficult to classify between BGV and Non_BGV. I tried to classify on the basis of time difference and export intensity, this criterions are so subjective and arbitrary that the results are not robust if the criterion were changed. Second limitation is concerned about sample used in this research. I surveyed venture companies just located in Seoul and Daejeon and also use only 84 samples which more or less provoke sample bias problem and generalization of results. I think the more following studies that focus on ventures located in other region, the better to verify the results of this paper.

  • PDF