• 제목/요약/키워드: Equilibrium investigation

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조직적 관점에서의 도서관 유효성에 관한 연구

  • 윤혜영
    • 한국도서관정보학회지
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    • 제29권
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    • pp.1-25
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    • 1998
  • Effectiveness is a major concern in organizations of all sorts. Library researchers have been particularly active recently in trying to define, measure, and promote library effectiveness. The purpose of this study is to place library effectiveness in the context of theoretical and empirical work on organizational effectiveness. Four major approaches to organizational effectiveness can be identified. The goal model defines an effective organizations as one that meets its goals. The system resource model emphasizes the organization's need to acquire resources from its environment. The process model sees organizations as social systems seeking to survive and maintain their equilibrium. The multiple constituencies defines effectiveness as the degree to which the needs and expectations of strategic constituencies are met. These models are not necessarily contradictory but may be seen as emphasizing different aspects of organizational performance or values. This study also reports four findings of the library effectiveness. They are significant as the empirical investigation into the dimensions of the construct of library effectiveness. The result shows that organizational effectiveness of libraries is, indeed, a multidimensional construct, implying that no single measure of effectiveness is sufficient to describe an organization.

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Lysino-Methylene-Ampicillin의 Rat 소장흡수(小腸吸收)에 관한 연구(硏究) (The Intestinal Absorption of Lysino-Methylene-Ampicillin in Rat)

  • 진금섭;김종갑;김재백
    • Journal of Pharmaceutical Investigation
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    • 제9권1호
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    • pp.15-19
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    • 1979
  • The absorption rate of lysino-methylene-ampicillin from the rat small intestine, compared with ampicillin, was determined in vitro and in situ to establish the biopharmaceutical properties of lysino-methylene-ampicillin which is one of the new penicillinase-resistance antibiotics. The half of administered dose was absorbed rapidly within thirty minutes. The water-oil distribution coefficient of lysino-methylene-ampicillin was 0.03 in chloroform versus buffer system with $Na_{2}HPO_{4}-citric$ acid of pH5.2 at $37^{\circ}C$, and its dissolution rate reached the plateau in an hour and then represented 0.6 percent of equilibrium solubility

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텐서그러티 기본유형 분류 및 응용 (Classification and applications of tensegrities)

  • 최선영;박선우;박찬수
    • 한국공간구조학회:학술대회논문집
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    • 한국공간구조학회 2005년도 춘계학술발표회 및 정기총회 2권1호(통권2호)
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    • pp.77-82
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    • 2005
  • Tensegrity is a relatively new sructural system (about more than 50 years old) based on the use of continuous tension-discontinuous compression. In spite of the controversial principles to define these systems, several examples of tensegrity prototypes constructed in IEDS(Institute of Environment Structure Design) are presented illustrating the feasibility of tensegrity as a lightweight structure. Of course, a much more detailed structural investigation would be necessary, but at least in order to achieve the intended purpose, it is essential to understand the structural principles and the fundamental forces of tensegrity. Once this point Is established, the characteristics of these structures are described, as well as applying them to architecture. Consequently, in this work, the patterns of basic module as well as fundamental definition are introduced. Then, the application of tensegrity to architecture has also been mentioned.

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Analytical and Numerical Results for the Liquid-Lubricated Magnetic Head-disk Interface Using Measured Rheological Data

  • Streator, Jeffrey L.
    • Tribology and Lubricants
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    • 제11권5호
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    • pp.93-98
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    • 1995
  • To increase the information storage density in magnetic disk files, the head, the headdisk spacing must be reduced. This has motivated the investigation of alternatives to the conventional air-lubricated head-disk interface (HDI), which operates at a spacing of about 100 nm. One such alternative under consideration is the liquid-lubricated bearing. To properly model the HDI with a liquid bearing it is necessary to incorporate the theological properties of liquid lubricants at high shear rates. These rheological properties themselves are most easily measured within the HDI. Recently, some question has arisen in the literature concerning the interpretation of the frictional data acquired in this manner. In this study analytical and numerical solutions of the Reynolds eqn. are applied to the starved, liquid lubricated HDI to provide some validation of the rheological data reported the author and coworkers (Streator et al., 1994). Results of the analysis highlight the importance of the inlet taper region in determining the equilibrium configuration of the starved HDI even when only a small fraction of its length is wetted by the lubricant.

Spragging 에 의한 터빈 베어링의 손상 및 방지 대책 (Analysis for Prevention of Spragging in the Turbine Bearings)

  • 하현천;양승헌
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 1999년도 제30회 추계학술대회
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    • pp.174-178
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    • 1999
  • This paper describes an investigation on bearing failure due to spragging that has been continuously occurred in turbine hearings. The spragging is defined as the damage found on the leading edge of unloaded pads in the tilting pad journal bearing, In general, the damage mechanism by spragging is classified into fatifgue failure, The principle cause of spragging could be thought as the self-excited vibration by the absence of a stable static equilibrium position of upper pads with no preload. Because of serious consequences of system breakdowns due to bearing failures, determination ar the causes of failure and effective method for countermeasures are very important. This paper describes both the causes of spragging and countermeasures for prevention of such failure, which are taken place in the electric power plants.

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전진비행시 복합재료 헬리콥터 회전익의 공탄성에 대한 파라미터 연구 (A Parametric Investigation Into the Aeroelasticity of Composite Helicopter Rotor Blades in Forward Flight)

  • 정성남;김경남;김승조
    • 소음진동
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    • 제7권5호
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    • pp.819-826
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    • 1997
  • The finite element analyses of a composite hingeless rotor blade in forward flight have been performed to investigate the influence of blade design parameters on the blade stability. The blade structure is represented by a single cell composite box-beam and its nonclassical effects such as transverse shear and torsion-related warping are considered. The nonlinear periodic differential equations of motion are obtained by moderate deflection beam theory and finite element method based on Hamilton principle. Aerodynamic forces are calculated using the quasi-steady strip theiry with compressibility and reverse flow effects. The coupling effects between the rotor blade and the fuselage are included in a free flight propulsive trim analysis. Damping values are calculated by using the Floquet transition matrix theory from the linearized equations perturbed at equilibrium position of the blade. The aeroelastic results were compared with an alternative analytic approch, and they showed good correlation with each other. Some parametric investigations for the helicopter design variables, such as pretwist and precone angles are carried out to know the aeroelastic behavior of the rotor.

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틸팅패드 스러스트베어링의 모멘트평형에 대한 고찰 (On Moment Balance of Tilting-Pad Thrust Bearings)

  • 김호종;최성필;하현천
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2003년도 학술대회지
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    • pp.261-266
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    • 2003
  • The present paper theoretically investigates characteristics of moment balance of a tilting-pad thrust bearing. Pressure of lubricant film of the bearing was computed using tile finite element method, and average film temperature was estimated from the heat balance over a pad. From the investigation, it has been found that different two sets of tilt angles satisfy moment equilibrium of the pad about tile pivot for a given pivot location. The tilt angles converged depend upon initial tilt angles assumed. Quite different bearing performance, including load capacity, film thickness, and temperature, is shown to be obtained based on choice of the initial tilt angles.

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알루미늄 합금박판 비등온 성형공정의 유한요소 해석 및 실험적 연구 (제2부:해석) (Finite Element Analysis and Experimental Investigation of Non-isothermal Forming Processes for Aluminum-Alloy Sheet Metals (Part2:Analysis))

  • 김성민;구본영;금영탁;김종호
    • 소성∙가공
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    • 제8권3호
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    • pp.252-261
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    • 1999
  • The 3-dimensional finite element program is developed to analyze the non-isothermal forming processes of aluminum-alloy sheet metals. Bishop's method is introduced to solve the heat balance and force equilibrium equations. Also, Barlat's non-quadratic anisotropic yield function depicts the planar anisotropy of the aluminum-alloy sheet. To find an appropriate constitutive equation, four different forms are reviewed. For the verification of the reliability of the developed program, the computational try-outs of the non-isothermal cylindrical cupping processes of AL5052-H32 and Al1050-H16 are carried out. As results, the constitutive equation relating to strain and strain-rate, in which the constants are represented by the 5th-degree polynomials of temperature, is in good agreement with measurement. The computational try-outs can predict optimal forming conditions in non-isothermal forming processes.

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광대역 불규칙 가진력을 받는 탄성진자계의 내부공진효과 (Influence of Internal Resonance on Responses of a Spring-Pendulum System under Broad Band Random Excitation)

  • 이원경;조덕상
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1997년도 춘계학술대회논문집; 경주코오롱호텔; 22-23 May 1997
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    • pp.86-94
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    • 1997
  • An investigation into the modal interaction of an autoparametric system under broad-band random excitation is made. The specific system examined is a spring-pendulum system with internal resonance, which is known to be a good model for a variety of engineering systems, including ship motions with nonlinear coupling between pitching and rolling motions. By means of the Gaussian closure method the dynamic moment equations explaining the random response of the system are reduced to a system of autonomous ordinanary differential equations of the first and second moments. In view of equilibrium solutions of this system and their stability we examine the system responses. The stabilizing effect of system damping is also examined.

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지도축척의 영향에 따른 하천형태학적 특성연구 (A study on stream morphological characteristics according to effect of Map Scale)

  • 안상진;조용진
    • 한국농공학회지
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    • 제23권1호
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    • pp.64-74
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    • 1981
  • The stream morphological characteristics of watershed have important influence upon the analysis of runoff. In this study, the effect of the map scale on the stream morphological characteristics was used on the data taken from 15'(1:50, 000) and 7'30"(1 :25,000) topographic maps which could cover the whole Miho River basin This basin are the first tributary of the Geum. River. Otherwise, the longitudinal stream bed profile was calculated by Yang's theoretical stream bed profile, equilibrium profile and actual profile. In the result of this investigation the conclusion is that the resultant relationship obtained from different topographic maps in the scale on the same stream system has come upon the same result as the stream morphological characteristics. Therefore, the great amount of time and effort can be saved in studing the stream morphological charecteristics by using the 15' instead of the 7'30"map system excluding the first order streams.

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