• Title/Summary/Keyword: Intended action

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Rotordynamic Analysis of a Turbo-Chiller with Varying Gear Loadings Part I ; A Driving Motor-Bull Gear Rotor-Bearing System (터보 냉동기의 변동 기어하중을 고려한 로터다이나믹 해석 Part I : 구동 모터-불기어 로터-베어링 시스템)

  • 이안성;정진희
    • Journal of KSNVE
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    • v.9 no.3
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    • pp.593-599
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    • 1999
  • A rotordynamic analysis is performed with a motor-bull gear rotor system supported on two partial bearings, which is intended to drive a high-speed turbo-chiller compressor impeller shaft through its built-in pinion gear. The motor-bull gear rotor system has a rated speed of 3,600 rpm, and is modeled utilizing the finite element method for analysis. As loadings on the bearings due to the gear action are significant in the system considered, each resultant bearing load is calculated statically by considering the generalized forces of the gear action as well as the rotor itself. The two support partial bearings are designed to take their varying loads along with their varying load angles, and they are also analyzed to give their rotordynamic coefficients. Then, a complex rotordynamic analysis of the motor-bull gear rotor-bearing system is carried out to evaluate its whirl natural frequencies and mode shapes and unbalance responses under various loading conditions. Results show that the bearings and entire rotor system are well designed regradless of operating conditions, i.e., loads and operating speeds.

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Effects of Houttuynia cordata Thunb Extract Inhibits on the Migration and Proliferation of Vascular Smooth Muscle Cell (어성초 추출물의 혈관 평활근 세포 이주 및 증식 억제 활성에 관한 연구)

  • Han, Jung-Ho;Park, Seon-Nam;Yoon, Mi-So;Choi, Ok-Byung
    • Korean Journal of Pharmacognosy
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    • v.42 no.2
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    • pp.182-186
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    • 2011
  • Houttuynia cordata Thunb.[H.cordata]belonging to Saururaceae, is a wild medicinal herb of perennial plants, and grows well in a place with a lot of shade and moisture. The medical action of H.cordata is reported to have an antitumer effect, toxicity-suppressive effect, antifungal effect, diuretic effect, and antioxidative action, but its effect hasn't been reported on cardiovascular diseases, such as ateriosclerosis and hypertension yet. This study intended to confirm the effect of the water extract of H.cordata on the migration and proliferation of rat aortic smooth muscle cells. Such results show that the water extract of H.cordata suppresses the migration and proliferation of rat aortic smooth muscle cells. It is believed that a useful clue will be offered later to the prevention of cardiovascular diseases such as ateriosclerosis and hypertension, and the development of their medicines on the basis of the fact.

Developing a Management Improvement Supporting Solution in Consideration of Service Quality (서비스품질을 고려한 경영혁신 지원 솔루션의 개발)

  • Park, C.S.;Ahn, S.E.;Shin, W.S.;Ryu, J.S.;Park, J.W.;Woo, M.K.
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.31 no.2
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    • pp.28-35
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    • 2008
  • Most organizations have recently put more emphasis on the improvement in service quality. This phenomenon could come from the recognition that service quality plays an essential role in enhancing organization's business performance. Hence this paper presents a framework for improving such service quality. The presented framework involves the methodology for (i) developing service quality indices, (ii) measuring and evaluating service quality, (iii) analyzing the level of service quality, (iv) constructing the quality improvement road map, (v) determining the quality improvement action plan. This methodology is intended to create self-sustaining improvement in service quality from the entire organization's perspective. An illustration is also given.

An Effect of SNS Performance and Arts Information Service Quality on Initial Trust and Prosumer Activity: Focusing on Dance Performance (SNS 공연예술 정보서비스품질이 초기신뢰와 프로슈머 활동에 미치는 영향: 무용공연을 중심으로)

  • Park, Sun-Woo;Cho, Chul-Ho
    • Journal of Korean Society for Quality Management
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    • v.44 no.1
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    • pp.199-214
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    • 2016
  • Purpose: The present study was designed to examine the casual relationships among performance and arts information service quality, initial trust, user satisfaction, reuse intention and prosumer activity in social network service(SNS). Also, we intended to explore significant factors on use performance of SNS through causal model analysis in the viewpoint of total effect. Methods: As a survey tool, questionnaire has obtained validity and reliability through literature survey, exploratory survey and pretest and sample 403 was selected. For statistical treatment of pretest and main analysis, SPSS18.0 and AMOS18.0 were employed and structural equation model was employed as analysis method. Results: Result of this study shows as follows. Two factors (precision and reciprocal action) have an effect on user satisfaction, initial trust, reuse intention and prosumer activity. We found that with an importance of initial trust, prosumer activity can be a useful and significant factor in causal relationship of SNS. Conclusion: The present study shows that two factors(precision and reciprocal action) in via of initial trust, were important factors that related companies have to emphasize to raise performance, And also we confirmed new factor 'prosumer activity' through this study. However, the present study has some limitations to be studied in the future.

Multiple characteristic response damage analysis of large-span space structures based on equivalent damping ratio

  • Wei, Jun;Yang, Qingshun;Zhou, Lexiang;Chen, Fei
    • Earthquakes and Structures
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    • v.23 no.4
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    • pp.339-352
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    • 2022
  • Due to the large volume and generally as a public building, the damage of large-span space structures under various non-conventional loads will cause greater economic losses, casualties, and social impacts, etc. Therefore, it is particularly important to evaluate the seismic performance of large-span space structures. This paper taked a multipurpose sports center as an example and considered its synergistic deformation based on the method of equivalent damping ratio. Furthermore, The ABAQUS software was used to analyze the time-history and energy response of the multipurpose sports center under the action of rare earthquakes, and proposed a quantitative damage index to assess the overall damage of the structure. Finally, the research results indicated that the maximum inter-story drift ratio of the multipurpose sports center under the action of rare earthquakes was less than its limit value. The frame beams presented different degrees of damage, but the key members were basically in an elastic state. The bearing capacity did not reach the limit value, which satisfied the intended seismic performance target. This study taked an actual case as an example and proposed a relevant damage evaluation system, which provided some reference for the analysis of the seismic performance of large-span space structures.

A Study on Intention Exchange-based Ship Collision Avoidance by Changing the Safety Domain

  • Kim, Donggyun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.3
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    • pp.259-268
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    • 2019
  • Even if only two ships are encountered, a collision may occur due to the mistaken judgment of the positional relationship. In other words, if an officer does not know a target ship's intention, there is always a risk of collision. In this paper, the experiments are conducted to investigate how the intention affects the action of collision avoidance in cooperative and non-cooperative situations. In non-cooperative situation, each ship chooses a course that minimizes costs based on the current situation. That is, it always performs a selfish selection. In a cooperative situation, the information is exchanged with a target ship and a course is selected based on this information. Each ship uses the Distributed Stochastic Search Algorithm so that a next-intended course can be selected by a certain probability and determines the course. In the experimental method, four virtual ships are set up to analyze the action of collision avoidance. Then, using the actual AIS data of eight ships in the strait of Dover, I compared and analyzed the action of collision avoidance in cooperative and non-cooperative situations. As a result of the experiment, the ships showed smooth trajectories in the cooperative situation, but the ship in the non-cooperative situation made frequent big changes to avoid a collision. In the case of the experiment using four ships, there was no collision in the cooperative situation regardless of the size of the safety domain, but a collision occurred between the ships when the size of the safety domain increased in cases of non-cooperation. In the case of experiments using eight ships, it was found that there are optimal parameters for collision avoidance. Also, it was possible to grasp the variation of the sailing distance and the costs according to the combination of the parameters, and it was confirmed that the setting of the parameters can have a great influence on collision avoidance among ships.

Prediction of cerebral infarction suppression mechanism of the Sagunja-Tang through network pharmacology analysis (네트워크 약리학 분석을 통한 사군자탕(四君子湯)의 뇌경색 억제 기전 예측)

  • Lim, Chiyeon;Lee, Byoungho;Cho, Suin
    • Herbal Formula Science
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    • v.30 no.4
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    • pp.293-304
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    • 2022
  • Objectives : Sagunja-Tang is a famous prescription used in Korean medicine for the purpose of promoting vital energy, and there are few studies using Sagunja-Tang on cerebrovascular diseases yet. As previous studies confirmed that Sagunja-tang is highly likely to be used effectively for stroke, this study was intended to predict the mechanism through which Sagunja-tang would act effectively on stroke. Methods : In this study, a network pharmacology analysis method was used, and oral bioavailability (OB), drug likeness (DL), Caco-2 and BBB permeability were utilized to select compounds with potential activity. For the values of each variable used in this study, OB ≥ 30%, DL ≥ 0.18, Caco-2 ≥ 0, and BBB ≥ 0.3 were applied. Using the above variables, the relations between target genes and diseases that are presumed to be involved in the selected bioavailable compounds were constructed in a network format, and proteins thought to play a major role were identified. Results : Among the compounds included in Sagunja-Tang, 26 bioavailable compounds were selected and it was confirmed that these compounds can be effectively used in cerebrovascular diseases such as Alzheimer's disease and stroke. These compounds are considered to act on proteins related in cell death and growth. The most important mechanism of action was predicted to be apoptosis, and the protein that is thought to play the most key action in this mechanism was caspase-3. Conclusions : In our future study, Sagunja-Tang will be used in an ischemic stroke mouse model, and the mechanism of action will be explored focusing on apoptosis and cell proliferation.

A Research on the Development of Performance Indicators and Action Plans for Academic Libraries in Korea (대학도서관 평가 지표 개발과 실행 방안에 관한 고찰)

  • Kwack, Dong-Chul
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.19 no.1
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    • pp.113-130
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    • 2008
  • Performance indicators for academic libraries in Korea suggested in this research cover three areas, that is, collection, budget, and human resources, which consists of three subdivisions, respectively. Performance indicators and action plans in this research were prepared, based on the official documents which universities in Korea formally submitted to the Ministry of Education and Human Resources, and the data published by the related institutions. Performance indicators and action plans are intended to draw attentions of university administrators and headquarters, but do not require librarians to prepare for evaluation. The better results would be expected with the development and application of both quantitative and qualitative indicators for information services by standardizing and unifying the process of collecting statistics. It is also expected that periodic and continuing evaluation of academic libraries could help government and universities have a better understanding of and appreciate the significance of academic libraries.

New horizon of geographical method (인문지리학 방법론의 새로운 지평)

  • ;Choi, Byung-Doo
    • Journal of the Korean Geographical Society
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    • v.38
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    • pp.15-36
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    • 1988
  • In this paper, I consider the development of methods in contemporary human geography in terms of a dialectical relation of action and structure, and try to draw a new horizon of method toward which geographical research and spatial theory would develop. The positivist geography which was dominent during 1960s has been faced both with serious internal reflections and strong external criticisms in the 1970s. The internal reflections that pointed out its ignorance of spatial behavior of decision-makers and its simplication of complex spatial relations have developed behavioural geography and systems-theoretical approach. Yet this kinds of alternatives have still standed on the positivist, geography, even though they have seemed to be more real and complicate than the previous one, The external criticisms that have argued against the positivist method as phenomenalism and instrumentalism suggest some alternatives: humanistic geography which emphasizes intention and action of human subject and meaning-understanding, and structuralist geography which stresses on social structure as a totality which would produce spatial phenomena, and a theoretical formulation. Human geography today can be characterized by a strain and conflict between these methods, and hence rezuires a synthetic integration between them. Philosophy and social theory in general are in the same in which theories of action and structural analysis have been complementary or conflict with each other. Human geography has fallen into a further problematic with the introduction of a method based on so-called political ecnomy. This method has been suggested not merely as analternative to the positivist geography, but also as a theoretical foundation for critical analysis of space. The political economy of space with has analyzed the capitalist space and tried to theorize its transformation may be seen either as following humanistic(or Hegelian) Marxism, such as represented in Lefebvre's work, or as following structuralist Marxism, such as developed in Castelles's or Harvey's work. The spatial theory following humanistic Marxism has argued for a dialectic relation between 'the spatial' and 'the social', and given more attention to practicing human agents than to explaining social structures. on the contray, that based on structuralist Marxism has argued for social structures producing spatial phenomena, and focused on theorising the totality of structures, Even though these two perspectives tend more recently to be convergent in a way that structuralist-Marxist. geographers relate the domain of economic and political structures with that of action in their studies of urban culture and experience under capitalism, the political ecnomy of space needs an integrated method with which one can overcome difficulties of orthhodox Marxism. Some novel works in philosophy and social theory have been developed since the end of 1970s which have oriented towards an integrated method relating a series of concepts of action and structure, and reconstructing historical materialism. They include Giddens's theory of structuration, foucault's geneological analysis of power-knowledge, and Habermas's theory of communicative action. Ther are, of course, some fundamental differences between these works. Giddens develops a theory which relates explicitly the domain of action and that of structure in terms of what he calls the 'duality of structure', and wants to bring time-space relations into the core of social theory. Foucault writes a history in which strategically intentional but nonsubjective power relations have emerged and operated by virtue of multiple forms of constrainst wihthin specific spaces, while refusing to elaborate any theory which would underlie a political rationalization. Habermas analyzes how the Western rationalization of ecnomic and political systems has colonized the lifeworld in which we communicate each other, and wants to formulate a new normative foundation for critical theory of society which highlights communicatie reason (without any consideration of spatial concepts). On the basis of the above consideration, this paper draws a new norizon of method in human geography and spatial theory, some essential ideas of which can be summarized as follows: (1) the concept of space especially in terms of its relation to sociery. Space is not an ontological entity whch is independent of society and has its own laws of constitution and transformation, but it can be produced and reproduced only by virtue of its relation to society. Yet space is not merlely a material product of society, but also a place and medium in and through which socety can be maintained or transformed.(2) the constitution of space in terms of the relation between action and structure. Spatial actors who are always knowledgeable under conditions of socio-spatial structure produce and reproduce their context of action, that is, structure; and spatial structures as results of human action enable as well as constrain it. Spatial actions can be distinguished between instrumental-strategicaction oriented to success and communicative action oriented to understanding, which (re)produce respectively two different spheres of spatial structure in different ways: the material structure of economic and political systems-space in an unknowledged and unitended way, and the symbolic structure of social and cultural life-space in an acknowledged and intended way. (3) the capitalist space in terms of its rationalization. The ideal development of space would balance the rationalizations of system space and life-space in a way that system space providers material conditions for the maintainance of the life-space, and the life-space for its further development. But the development of capitalist space in reality is paradoxical and hence crisis-ridden. The economic and poltical system-space, propelled with the steering media like money, and power, has outstriped the significance of communicative action, and colonized the life-space. That is, we no longer live in a space mediated communicative action, but one created for and by money and power. But no matter how seriously our everyday life-space has been monetalrized and bureaucratised, here lies nevertheless the practical potential which would rehabilitate the meaning of space, the meaning of our life on the Earth.

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Fracture Analysis of Flexural-Shear Failure in RC Beams (철근콘크리트보의 휨-전단균열에 대한 파괴역학적 해석)

  • Lim, Cheol-Won;Kim, Dae-Joong;Kim, Woo
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10a
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    • pp.418-423
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    • 1998
  • This paper is intended to investigate the behavior of flexural-shear cracking in reinforced concrete beams without web reinforcement with FEM incorporated into a linear elastic fracture mechanics approach(LEFM). Each crack was propagated progressively by a finite length, then the quantitative reponses were examined. The results show that the horizontal crack was initiated by the bond-jnduced shear stress due to horizontal shearing action of the T-C force couple after the formation of the critical flexural crack. Also, the horizontal crack is considered to be a major factor of shear failure in slender reinforced concrete beams without web reinforcement.

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