• 산업기술연구
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• 제27권A호
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• pp.47-53
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• 2007

A theoretical model based on Rayleigh-Ritz method is proposed to predict the resonance frequency of a W/T(Wind Turbine) tower structure supported by guy cables. In order to verify the validity of the theoretical model, a reduced W/T tower system is manufactured and tested. Frequency response and mode data are determined by modal testing and finite element analysis is performed to calculate the natural frequency of the tower model. Numerical and experimental results are compared with those by the theoretical analysis. Parametric study by the theoretical model shows how the cable tension and cable elasticity influence the resonance frequency of the W/T tower structure. Finally, vibration response under various rotating speed is investigated to examine the possibility of severe resonance.

• 한국해양공학회지
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• 제14권1호
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• pp.6-10
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• 2000

In this paper various methods of determining of wave loads acting ofshore structures including impact load due to breaking wave are studied and corresponding model test was performed. In the theoretical approach wave load by nonbreaking wave and impact load by breaking wave is determined by Morrison's equation Goda's equation and impact wave equation, In the experimental approach wave load by nonbreaking wave acting on cylindrical pile used in offshore structures is determined by measuring the strain on a cylindrical pile and compared with theoretical calue. in the numerical approach impact load by breaking wave acting on a modeled cylindrical pile is calculated by usign ANSYS FEM program and compared with theoretical value. It is found that the experimental and numerical results are comparable to theoretical results, Thus the determination of wave load acting on offshore structures can be obtained by a proposed methods and it acceptable.

• Advances in aircraft and spacecraft science
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• 제1권2호
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• pp.177-196
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• 2014

A theoretical exploration for determining the characteristic length of the cohesive zone for a double cantilever beam (DCB) specimen under mode I loading was conducted. Two traction-separation laws were studied: (i) a law with only a linear elastic stage from zero to full traction strength; and (ii) a bilinear traction law illustrating a progressive softening stage. Two analytical solutions were derived for the first law, which fit well into two existing solution groups. A transcendental equation was derived for the bilinear traction law, and a graphical method was presented to identify the resultant cohesive zone length. The study using the bilinear traction law enabled the theoretical investigation of the individual effects of cohesive law parameters (i.e., strength, stiffness, and fracture energy) on the cohesive zone length. Correlations between the theoretical and finite element (FE) results were assessed. Effects of traction law parameters on the cohesive zone length were discussed.

• 정보저장시스템학회논문집
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• 제2권2호
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• pp.111-116
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• 2006

The purpose of this paper is to study the effects of the flexibility of HDD base plates on spindle vibration via theoretical predictions and experimental measurements. The flexibility of the base plate can significantly affect HDD spindle vibration. This is the most prominent feature in 2.5 inch HDD. Nevertheless, theoretical analysis of the spindle vibration often neglects the flexibility of the non-rotating part including spindle, base plate, and top cover. Our theoretical model developed in University of Washington can include the flexibilities of spindle and base plate. As a result, our theoretical prediction generally agrees well with our experimental measurements in vibration analysis. Moreover, because of its small form factor, industrial practice is to use flanged disks instead of regular disks in vibration testing of prototypes. Our experimental measurements indicate that flanged disks and regular disks have very different behavior when the frequency is above 1 KHz.

• Bulletin of the Korean Chemical Society
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• 제19권5호
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• pp.539-544
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• 1998

A new theoretical method, named the SCF-DWB-IOS approximation, is suggested to investigate the vibrational predissociation of triatomic van der Waals complexes. The meta stable vibrational excited states are described with SCF (self-consistent-field) approximation and the fragmented diatomic continuum states are determined by using IOS (infinite order sudden) approximation. The dissociation process itself is studied by using DWB (distorted wave Born) approximation. As a test case, the predissociation rates, rotational state distributions of products, and the lifetimes of vibrationally excited states of $Ne-I_2$ are all computed which are in reasonable agreements with other theoretical and/or experimental results. The suggested SCF-DWB-IOS approximation scheme is found to be a very simple but efficient theoretical tool to investigate the vibrational predissociation dynamics of small van der Waals complexes.

• 산업경영시스템학회지
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• 제20권42호
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• pp.121-130
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• 1997

The purpose of this study was to find altermatives on restructuring of distribution system and rationalization of management in tourism industry. A theoretical approach was used to determine how principle concepts and strategies in marketing can be applied into tourism industries.

• 한국산학기술학회논문지
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• 제18권1호
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• pp.66-74
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• 2017

본 연구는 조기 정신증 환자를 대상으로 포괄적인 간호중재를 제공함으로써 정신증 진행을 늦추고 정신기능의 불구를 줄여 사회적 기능이 최적으로 호전될 수 있도록 돕는 새로운 돌봄의 이론적 모형을 개발하기 위해 시도되었다. 본 연구에서는 조기 정신증 환자의 돌봄에 대한 이론적 모형을 구축하기 위해 1) 연구주제 및 자료 분석방법 결정, 2) 문헌탐색 및 분석대상 선택, 3) 자료 추출, 4) 예비모형 구축 및 타당도 검증의 단계를 적용하였다. 2000년대 이후 '조기 정신증 돌봄'에 대해 실시된 선행문헌중 본 연구대상에 선정된 19개 문헌에 대해 질적 메타분석를 실시하였다. 그 결과 일차 분석틀에서 개별 연구에 나타난 조기 정신증 돌봄 요인 51개를 추출하고 이를 21개의 중분류로 나누었으며 이차 분석틀에서 요인의 속성이 유사한 것끼리 모아 8개의 범주명을 제시하였다. 또한 돌봄 요인에 대한 범주명을 간호사와 환자가 건강과 관련된 어려움을 해결하는 대인관계에 초점을 둔 중범위 이론인 Peplau의 대인관계이론을 기틀로 하여 예비모형을 구축하였다. 본 연구는 지역사회 접근을 통해 조기 정신증 환자의 치료받지 않는 기간을 줄이고 개인의 발달기와 환경에 적합한 간호중재를 제공해 줌으로써 사회적 기능을 증진시킬 수 있는 돌봄 모형의 중요한 토대가 될 수 있다.

• Steel and Composite Structures
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• 제22권5호
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• pp.1085-1114
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• 2016

This paper investigates the transverse impact response for ultra lightweight cement composite (ULCC) filled pipe-in-pipe structures through a parametric study using both a validated finite element procedure and a validated theoretical model. The parametric study explores the effect of the impact loading conditions (including the impact velocity and the indenter shape), the geometric properties (including the pipe length and the dimensions of the three material layers) as well as the material properties (including the material properties of the steel pipes and the filler materials) on the impact response of the pipe-in-pipe composite structures. The global impact responses predicted by the FE procedure and by the theoretical model agree with each other closely. The parametric study using the theoretical approach indicates the close relationships among the global impact responses (including the maximum impact force and the maximum global displacement) in specimens with the equivalent thicknesses, proposed in the theoretical model, for the pipe-in-pipe composite structures. In the pipe-in-pipe composite structure, the inner steel pipe, together with the outer steel pipe, imposes a strong confinement on the infilled cement composite and enhances significantly the composite action, leading to improved impact resistance, small global and local deformations.

• Asian Pacific Journal of Cancer Prevention
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• 제17권12호
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• pp.5133-5138
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• 2016

Background: Breast cancer is one of the most common cancers and a major public health problem in developing countries. However, early detection and treatment may be achieved by breast self-examination (BSE). Despite the importance of BSE in reducing the incidence of breast cancer and esultant deaths, the disease continues to be the most common cause of cancer death among women in Iran.This study aimed to determine the effects of self-care education on performance of BSE among women referring to health centers in our country. Materials and Methods: This quasi-experimental interventional study with pretest/posttest control group design was conducted on 168 women referred to health centers. The data were collected using a validated researcher-made questionnaire including demographic variables and trans-theoretical model constructs as well as a checklist assessing BSE behavior. The instruments were administered to groups with and without self-care education before, a week after, and 10 weeks after the intervention. Then, the data were entered into the SPSS statistical software (version 19) and analyzed using independent sample t-tests, paired sample t-test, repeated measures ANOVA, Chi-square, and Friedman tests (p<0.05). Results: The results showed an increase in the intervention group's mean scores of trans-theoretical model constructs (stages of change, self-efficacy, decisional balance, and processes of change) and BSE behavior compared to the control group (p<0.001). Conclusion: The study confirmed the effectiveness of aneducational intervention based ona trans-theoretical model in performing BSE. Therefore, designing educational interventions based on this model is recommended to improve women's health and reduce deaths due to breast cancer.

• 한국사회복지학
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• 제43권
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• pp.193-221
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• 2000

The conventional framework of welfare politics, based on class concepts, tends to fail in explaining the recent social changes. Theoretical response from the social science diverges into two blocs. One is the postmodernist approach that denies possibility of structural cleavage; the other is the alternative trial that seeks to find various kinds of cleavages. The former approach is to be rejected because there is few empirical supports for it. The latter is too sparse to be applied to the studies of welfare politics that requires a comprehensive analysis. This study starts from critical investigation of such approaches, aiming at providing a theoretical framework that combines merits of existing studies on welfare politics. The theoretical framework of three statuses of welfare rights and duties, which is to be presented as an alternative to the conventional class counterpart, does not only underscore the expansion of welfare rights but also the burden of welfare duties. Hence, it can comprehensively subsume complex existence of interest cleavages of welfare politics. To make a long story short, individual interest, related to the welfare state, will effect individual attitudes toward the welfare state and their ways of political support.