• Title/Summary/Keyword: External change

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Damping Effects of a Flexible Structure Interacting with Surrounding Acoustic Fluid (주변 음장과 연동하는 탄성 구조체의 감쇠 효과)

  • Lee, Moon-Seok;Park, Youn-Sik;Park, Young-Jin
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.7
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    • pp.718-724
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    • 2008
  • A flexible structure submerged in acoustic fluid is affected by its surrounding fluid. In this case, the coupling effects between structures and surrounding fluid have an effect on the submerged structure as external force and change impedance of acoustic domain. Therefore, the coupling effects by its surrounding fluid complicatedly change the characteristics of a submerged structure such as natural frequencies and damping coefficients. In this paper, using the analytic modal equation of a spherical shell surrounded by water and air, the complex changes of damping coefficients and natural frequencies of submerged structures are studied for various external acoustic fluid and structures.

A Study on the Fluid Flow by Change of Pressure & Flow in the Collapsible Tube (압출관에서의 압력 및 유형변화에 따른 유체유동에 관한 연구)

  • Kim, Jong-Eok;Lee, Han-Yeong;Hong, Gi-Bae
    • Journal of Biomedical Engineering Research
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    • v.5 no.1
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    • pp.47-54
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    • 1984
  • In order to research the flow in the thin wall compliant tube, this present study is attempt to measure the cross sectional area according to change of external pressure and flow by ultrasonic method different from willy used impedance technique for flow analysis about one dimensional Steads flow. The experimental results are as follows. 1) Measurement of cross sectional area ratio by ultrasonic method by comparison with experimental results of impedance technique & theoretical results were well consent. 2) Pressure difference of upstream and down stream is alwap's maximum range at 0.4 < $\alpha$ <0.5, and have no connection with changing external pressure. 3) when the external pressure is fixed and resistance is varied, Self excited oscillation occurs in the region at 0.5 < $\alpha$ <0.6, and oscillation disappear almost at R2>=1.2

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Modeling Diffusion Process Under Abrupt Changes of External Factors (외생변수가 급변하는 상황에서의 확산과정 모형화)

  • Park Sang-June;Hahn Min-Hi;Shin Chang-Hoon
    • Journal of the Korean Operations Research and Management Science Society
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    • v.31 no.2
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    • pp.15-26
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    • 2006
  • In reality, we can observe anomalous diffusion patterns of cycle-recycle or rejuvenation. Abrupt changes in the market environment such as sudden currency devaluation or change in government policy or those in marketing strategies such as drastic repositioning can lead to such atypical diffusion patterns. The authors present extended Bass models that incorporate effects of such abrupt changes of external factors into the hazard rate and the market potential. Using a set of compact-car data affected by a drastic change in the government policy, they illustrate the strengths of the proposed models.

Deduction of Change Management Factors and Weight Estimation based on ANP in Urban Renewal Project (ANP 기반 도시환경정비사업의 변화관리 요인 도출 및 중요도 산정)

  • Shin, Seung-Yoon;Son, Myung-Jin;Hyun, Chang-Taek
    • Korean Journal of Construction Engineering and Management
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    • v.14 no.3
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    • pp.176-186
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    • 2013
  • For urban renewal projects progressing in large scale, it carries a characteristic that frequently changes the environment, subject, law, plan and the like by a demand from various participants and internal/external factors. As such large-scale urban renewal projects have a lot of possibilities of change, it requires setting a plan to recognize the possible variable factors by each project operation stage and to manage it systematically by defining the variable factors on the basis of working process of the entire project. Therefore this research has produced a factor of main variable management based on working process for systematic variable management on the projects that inherent various possibilities of change as urban environment refurbishment projects. And it also suggests the status of main variable factors characterized by project operation stages quantitatively through reflecting external and internal features for variable factors produced from utilizing ANP methodology.

Study on the Ultimate Flexural Behavior Analysis of Prestressed Concrete Beam with External Unbonded Tendons (외적 비부착강선을 가진 프리스트레스트 콘크리트 보의 극한휨거동 해석)

  • 오병환;유성원;신정성
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10b
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    • pp.662-667
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    • 1998
  • Recently, the using PSC with external unbonded tendons is increased. However, the behavior of external unbonded tendons is different with that of bonded internal tendon at ultimate state by compatibility condition, the slip with friction at deviator and the change of tendon eccentricity e.t.c., So, the analytical research considered the effect of these inherent characters was performed and the tendency of external unbonded tendons was estimated by numerical examples. By the analytical results, load-deflection relationship and stress increment of external unbonded tendons were similar to those of internal bonded tendon at initial elastic behavior state. Those characters were, however, smaller than those character of internal bonded tendons. For external unbonded tendons, if the 1 deviator which is positioned at maximum moment point and more 2 deviators which are position between maximum moment point and support are existed, the flexural behavior is similar to internal bonded tendons.

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The Relationship between the Factors and Performance of Environmental Management (환경경영요인과 성과에 관한 연구)

  • 김형욱;노지혜
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1998.10a
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    • pp.202-206
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    • 1998
  • The conventional management which had economic requirement such as productivity, competition, customer satisfaction, and return needs the environmental management in order to meet a change of the external situation such as the environmental requirement (such as resources reduction, pollution prevention, and waste reduction). However, there have been a few studies which try to investigate internal factor and to regard external factors as negative ones. This paper proposes the external factors are significant to the performance. Several hypotheses were developed regarding the relationships. Based on the collected data from 126 firms, the hypotheses were analyed with SPSS.

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A Study on Dynamic Behaviors of Steel Plate Girder bridge with Applying External Post-Tensioning Method (외부 후긴장 공법 적용에 따른 무도상 판형교의 동적거동 분석)

  • Choi, Dong-Ho;Choi, Jung-Youl;Choi, Jun-Hyeok;Park, Yong-Gul
    • Journal of the Korean Society for Railway
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    • v.9 no.2 s.33
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    • pp.160-168
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    • 2006
  • The major objective of this study is to investigate the effects and application of external post-tensioning method far steel plate girder bridge. It analyzed the mechanical behaviors of steel plate girder bridge with applying external post-tensioning on the finite element analysis, field test and laboratory test fur the lateral dynamic characteristics. As a result, the reinforcement of steel plate girder bridge the external post-tensioning method are obviously effective for the lateral dynamic response which is non-reinforced. The analytical and experimental study are carried out to investigate the post-tension force decrease lateral acceleration and deflection on steel plate girder bridge for serviceability. And the external post-tensioning method reduce dynamic maximum displacement(about $10{\sim}24%$), the increase of dynamic safety is predicted by adopting external post-tensioning method. From the dynamic test results of the servicing steel plate girder bridge, it is investigated that the change degree of natural frequency is very low with applying the external post-tensioning method The servicing steel plate girder bridge with external post-tensioning has need of the reasonable reinforcement measures which could be reducing the effect of lateral dynamic behavior that degradation phenomenon of structure by an unusual response characteristic and a drop durability.

The Comparative Study on Performance Evaluation of Outdoor Space for Remodeling Apartment (리모델링 공동주택단지의 외부공간 성능평가 비교 연구)

  • Kim, Ho-Yun;Lee, Sang-Suk;Yu, Joo-Eun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.19 no.4
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    • pp.1-17
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    • 2016
  • In this study, remodeling projects are perceived as a sustainable urban management policy to boost the value of old apartments and stimulate urban regeneration and development. To evaluate the physical environmental performance of external spaces of remodeled apartments, an evaluation model was developed. After applying it to the target places, the following results were obtained. First, analysis of the external space change index of the target apartments revealed that institutional standards are necessary in line with the building arrangement type, parking lot expansion method, and changes in the building-to-land ratio. Second, the score ratio as to the external space change index performance is as follows: safety (48.30); pleasantness (25.90); convenience (18.90); eco-friendliness (14.90). In other words, "safety" had the biggest score ratio. Third, to boost the external space performance of remodeled apartments, the needs of residents and neighboring environmental plans should be considered from a communality standpoint.

4-channel Light Medical Therapy Apparatus for External Injury Cure (체외 상처 치유를 위한 4-채널 광 치료기)

  • Cheon, Min-Woo;Kim, Seong-Hwan;So, Keum-Young;Moon, Young-Lae;Mun, Seong-Pyo;Park, Yong-Pil;Lee, Ho-Sik;Kim, Tae-Gon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.8
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    • pp.731-735
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    • 2007
  • We developed the 4channel Light Medical Therapy Apparatus for External Injury Cure using a high brightness LED. This equipment was fabricated using a micro-controller and a high brightness LED, and designed to enable us to control light irradiation time, intensity, frequency and so on, Especially, to control the light irradiation frequency, FPGA was used, and to control the change of output value, TLC5941 was used. Control stage is divided into 4 levels by program. Consequently, the current value could be controlled by the change of level in Continue Wave(CW) and the output of a high brightness LED could be controlled stage by stage. Compared with one LED irradiation, several LEDs irradiation could increase optical power.

소비자파워에 의한 갈등이 경로관리에 미치는 영향

  • 서봉철
    • Journal of Distribution Research
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    • v.1 no.1
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    • pp.83-107
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    • 1996
  • The concern of external environment is growing up in the field of channel distribution. In the former channel distribution, the channel distribution environment is little bit unmoveable owing to a powerful manufacture control against poor distributor. Therefore intra-efficiency is channel member's core interest. The structure of channel governance, however, come to be changable because of the mature distributor power against manufacturer such as a Price Break, JIT of channel governance, and a serial of change. Accordingly, it is acceptable that the interest of external-environment of channel members' is more and more enlarged, and external-environment change in the channel distribution make the serious problems in intraorganizational system. Thus, it is meaningful that this study try to discover the consumer power as external environment factor and to find the best strategy to overcome this consumer power. Resource dependence theory, Transaction cost theory, Political Economic Approach, and Working partnership Approach are the theory foundation of the reasearch. Apparel franchise is a sample to analyse the hypothesis and correlation and multi-regression are a chief tools to estimate the hypothesis. Thus, the above results imply that a flexible governance is appropriate to consumer power, conflict is not intervening value between consumer power and channel governance, and the channel member's satisfaction can be confirmed in the flexible governance better than control governance.

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