• Title/Summary/Keyword: criteria of stability

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The Comparison of the Stability of a Container Crane according to various Wind Load Design Codes (풍하중 설계 기준에 따른 컨테이너 크레인의 안정성 비교)

  • Lee Seong-Wook;Shim Jae-Joon;Han Dong-Seop;Han Geun-Jo;Kim Tae-Hyung
    • Journal of Navigation and Port Research
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    • v.29 no.6 s.102
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    • pp.561-566
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    • 2005
  • This study was carried out to amlyze and compare the stability of a 50ton container crane according to various wind load design codes. The wind load was evaluated according to 'The Specification of Port Facilities and Equipments / Specification for the design of crane structures (KS A 1627)' and 'Load Criteria of Building Structures' effected by the ministry of construction & transportation And the uplift forces qf a container crane under this wind load were estimated by amlyzing reaction forces at each supporting point and compared each other. From this study, we noticed that the design wind velocity criteria need to be defined specifically when the wind load is evaluated to design a container crane. And we verified the necessity of the estimation of the uplift forces at each supporting point to analyze a structural stability of a container crane and the maximum compressive force in order to consider the stability of the ground foundation of the berth.

A Study on the Introduction of Early Warning System for Slope Failure (사면붕괴 예.경보시스템 도입에 관한 연구)

  • Kim, Hak-Seung;Cho, Nam-Jun
    • Journal of the Korean Society of Hazard Mitigation
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    • v.4 no.3 s.14
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    • pp.9-17
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    • 2004
  • In recent years slope failure due to heavy rainfalls or local downpours usually accompanied by typhoons has increasingly occurred in Korea. Also, the damages caused by slope failure have a tendency to be more disastrous than before. This study has been conducted to prepare an early warning system for slope failure by : (1) analyzing types and causes of slope failure, (2) examining the published evaluation criteria for slope stability, (3) estimating slope stability by considering the properties of slope-forming materials as well as the topographical and geological properties of slopes, and (4) determining the most important variables of affecting the stability of the slope under consideration. The data on the variations of slope conditions measured by an automatic in-situ measurement system and then transmitted to the central analysis system by using an internet. The most important variables can be back-calculated in the central system and compared with the values for the first and second management criteria. These management criteria should be modified and corrected continuously in the future by accumulated data and knowledge related to the early warning system for slope failure.

Evaluative Criteria of Cyber Store based on Consumer Character of Cyber Stove Shoppers (사이버쇼핑 이용자의 소비자특성에 따른 가상점포 평가기준)

  • 박재옥;안민영
    • Journal of the Korean Society of Clothing and Textiles
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    • v.27 no.3_4
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    • pp.441-451
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    • 2003
  • The purpose of this study was to find out evaluative criteria of cyber store toward shopping orientation, purchasing experience and demographic factors of consumers to visit cyber store. This study surveyed consumers who have an experience of using cyber store and judgment sampling was used. The respondents were 240 men and women living in the metropolitan area of Seoul and Gyeonggi province. Research method was measured by clothing shopping orientation (utilitarian and hedonic factors), cyber store evaluation criteria (convenience, quality & trust and product character factors), purchasing experience(existent and nonexistent) and demographic factors. For data analysis, descriptive statistics, factor analysis, cluster analysis, ANOVA, t-test, Duncan test, and reliability analysis were conducted. The results were as follows: 1. Evaluative criteria of cyber store were considered importantly in order of possibility of exchange and refund, stability of personal information security, substance of quality degree of product and service and store. 2. Among shopping orientation groups, there were significant differences in all evaluative criteria of cyber store: convenience, quality & trust and product character of store. 3. Among groups toward existence and nonexistence in a purchasing experience, there were significant differences in convenience and quality & trust of store. 4. Among Demographic factors(gender, job, education and income) there were significant differences in convenience and quality & trust of store.

Development of Sustainability Criteria for Forest Landuse Planning (지속가능한 산지개발을 위한 환경기준 설정에 관한 연구)

  • Youn, Yeo Chang;Kim, Sang Yoon;Kwon, Tae Ho;Lee, Chang Suk
    • Journal of Environmental Impact Assessment
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    • v.8 no.2
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    • pp.53-63
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    • 1999
  • This study aims to develop a set of criteria for evaluating the sustainability of forest landuse, which could facilitate the environmentally friendly development of forest lands in Korea. The concept of sustainable development in forest landuse was reviewed from literature and by interviews with experts in forest-related fields. Delphi technique was employed for gathering experts' opinions. According to the results of Delphi test, the concept of sustainable development in forest landuse was confirmed as "Use of forest lands in a lasting manner within the carrying capacity of the ecosystem involved". There are 16 factors which should be considered with care when the development of forest lands is planned. They include the ratio of forest cover left undeveloped, ecological stability, and landscape naturalness. Among them are the ecological factors rated most important. The experts emphasized the importance of local characteristics in setting up the criteria for sustainable forestland development. The study did not attempted to apply the criteria to real settings. Therefore, before applications in real situations, further case studies should be made for the criteria to be safely used in landuse planning.

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An Experimental Study on IMO 2nd Generation Stability Assessment in Dead Ship Condition of 13K Chemical Tanker (13K Chemical Tanker의 기관 제어 불능상태 IMO 2세대 안정성 평가에 관한 실험적 연구)

  • Lee, Sang-Beom;Moon, Byung-Young
    • Journal of the Society of Naval Architects of Korea
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    • v.59 no.2
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    • pp.89-95
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    • 2022
  • The stability of the existing ships has been evaluated through numerical calculations in the steady-state, but recently the IMO proposed a new stability assessment criteria that the stability is evaluated in the state in which environmental loads from such as waves and wind act like the loads under actual ship operating conditions. In this study, IMO 2nd generation stability assessment method and procedure were summarized for the dead ship condition, and Direct Stability Assessment (DSA) was performed on 13K chemical tanker through basin model test. The model test is performed in the ocean engineering basin to implement wave and wind loads, and environmental conditions for waves were set height and period of the incident wave, considering the regular wave and wind generation range reproducible in the ocean engineering basin. In addition, to consider the effect of wind speed, the Beaufort Scale for wind speed was applied in the model test.

Review of the Intact Stability(Problems) for Ships Carrying Timber Deck Cargoes (갑판적 목재운반선의 비손상 복원성에 관한(문제점) 검토)

  • I.H.,Chang;C.J.,Kim
    • Bulletin of the Society of Naval Architects of Korea
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    • v.26 no.3
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    • pp.71-78
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    • 1989
  • A series of total loss of log carriers of G/T 4000 class which are engaged in EAST-SOUTH ASIAN route have been reported during the last decade. The casualties has been investigated in depth to draw the efficient means of safety. The results of this investigation, which are described in this paper, have been submitted to INTERNATIONAL MARITIME ORGANIZATION(IMO) by KOREAN GOVERNMENT in cooperation with the KOREAN REGISTER OF SHIPPING to request the revision of stability criteria of ship carrying timber deck cargoes.

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DYNAMICS OF A DELAY-DIFFUSION PREY-PREDATOR MODEL WITH DISEASE IN THE PREY

  • MUKHOPADHYAY B.;BHATTACHARYYA R.
    • Journal of applied mathematics & informatics
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    • v.17 no.1_2_3
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    • pp.361-377
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    • 2005
  • A mathematical model dealing with a prey-predator system with disease in the prey is considered. The functional response of the predator is governed by a Hoilling type-2 function. Mathematical analysis of the model regarding stability and persistence has been performed. The effect of delay and diffusion on the above system is studied. The role of diffusivity on stability and persistence criteria of the system has also been discussed.

A DELAY-DIFFERENTIAL EQUATION MODEL OF HIV INFECTION OF CD4+ T-CELLS

  • SONG, XINYU;CHENG, SHUHAN
    • Journal of the Korean Mathematical Society
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    • v.42 no.5
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    • pp.1071-1086
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    • 2005
  • In this paper, we introduce a discrete time to the model to describe the time between infection of a CD4$^{+}$ T-cells, and the emission of viral particles on a cellular level. We study the effect of the time delay on the stability of the endemically infected equilibrium, criteria are given to ensure that the infected equilibrium is asymptotically stable for all delay. We also obtain the condition for existence of an orbitally asymptotically stable periodic solution.

Evaluation of dam strength by finite element analysis

  • Papaleontiou, Chryssis G.;Tassoulas, John L.
    • Earthquakes and Structures
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    • v.3 no.3_4
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    • pp.457-471
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    • 2012
  • Current code procedures for stress and stability analysis of new and existing concrete-gravity dams are primarily based on conventional methods of analysis. Such methods can be applied in a straightforward manner but there has been evidence that they may be inaccurate or, possibly, not conservative. This paper presents finite element modeling and analysis procedures and makes recommendations for local failure criteria at the dam-rock interface aimed at predicting more accurately the behavior of dams under hydraulic and anchoring loads.

An Analysis on Effects of Phase Compensation on Power System Stability in the PSS Parameter Tuning (PSS Tuning시 위상보상이 계통안정도에 미치는 영향 분석)

  • Kim, Tae-Kyun;Shin, Jeong-Hoon
    • Proceedings of the KIEE Conference
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    • 1998.07c
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    • pp.1147-1149
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    • 1998
  • This paper presents the result of an analysis on effects of phase compensation on power system stability in the PSS parameter tuning. Synchronizing and damping coefficients are induced from lineal model for generator with PSS. Synchronizing and damping coefficients corresponding to time constants of phase compensation control block are calculated on a single machine, infinite bus test system. The Parameter tuning concepts, basic function, structural elements and performance criteria of PSS are introduced.

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