• International Journal of Aeronautical and Space Sciences
• /
• 제10권2호
• /
• pp.23-33
• /
• 2009

The inherent aeromechanical complexity of a rotor system necessitated the comprehensive analysis code for helicopter rotor system. In the present study, an aerodynamic analysis module has been developed as a part of rotorcraft comprehensive program. Aerodynamic analysis module is largely classified into airload calculation routine and inflow analysis routine. For airload calculation, quasi-steady analysis model is employed based on the blade element method with the correction of unsteady aerodynamic effects. In order to take unsteady effects - body motion effects and dynamic stall - into account, aerodynamic coefficients are corrected by considering Leishman-Beddoes's unsteady model. Various inflow models and vortex wake models are implemented in the aerodynamic module to consider wake induced inflow. Specifically, linear inflow, dynamic inflow, prescribed wake and free wake model are integrated into the present module. The aerodynamic characteristics of each method are compared and validated against available experimental data such as Elliot's induced inflow distribution and sectional normal force coefficients of AH-1G. In order to validate unsteady aerodynamic model, 2-D unsteady model for NACA0012 airfoil is validated against aerodynamic coefficients of McAlister's experimental data.

• 한국응용과학기술학회지
• /
• 제36권2호
• /
• pp.507-523
• /
• 2019

본 연구는 유도체육관 운영 및 이용에 영향을 미치는 입지와 서비스 요인을 분석하는데 목적이 있으며, 원활한 유도체육관 운영을 위하여 수련생의 만족에 영향을 미칠 수 있는 요인에 대해 가이드(guide)가 될 수 있는 실증적 자료를 제시하는데 의의가 있다. 이를 위해 총 350부의 설문지를 배포하여 불성실하게 응답된 11부를 제외하고 총 339부를 유효표본으로 사용하였다. 분석을 위해 IBM SPSS 21을 이용하여 빈도분석, 탐색적 요인분석, Cronbach's ${\alpha}$, 상관관계분석, 다중회귀분석을 실시하였다. 분석을 통한 결과는 다음과 같다. 우선 유도체육관 운영 및 이용에 영향을 미치는 입지와 서비스 요인이 수련생의 만족도에 미치는 영향에 대해서 운영, 지도자, 커뮤니케이션, 수련생가치, 시설, 입지 요인 순으로 모두 수련생 만족에 유의한 영향을 미치는 것으로 나타났다. 하위요인별로 살펴보면, 첫째, 운영 요인에서 상해보험 가입 여부, 체육관 자유로운 이용, 운동 프로그램 운영 요인 순으로 수련생 만족도에 유의한 영향을 미치는 것으로 나타났으며, 둘째, 지도자 요인에서는 지도자 신뢰도 요인이 영향을 미쳤고, 셋째 커뮤니케이션 요인에서는 회원 간 의사소통 요인이 영향을 미치는 것으로 나타났다. 그리고 넷째, 수련생가치 요인에서는 건전한 여가활동과 운동수행능력 향상 요인 순으로 영향을 미쳤고, 다섯째, 시설 요인에서는 부대시설 수준과 주요시설 수준 요인 순으로 영향을 미치는 것으로 나타났으며, 여섯째, 입지 요인에서는 체육관의 가시성 여부 요인만이 영향을 미치는 것으로 나타났다. 유도체육관 입지 형태(역세권, 주거지역, 상업지역)에 따른 체육관 특성의 차이에 대해서는 우선 역세권에 위치한 체육관은 수련생가치, 입지, 커뮤니케이션, 시설이 수련생 만족에 유의한 영향을 미치는 것으로 나타났으며, 주거지역에 위치한 체육관은 운영, 수련생가치, 커뮤니케이션, 시설이 수련생 만족에 유의한 영향을 미치는 것으로 나타났고, 상업지역에 위치한 체육관은 운영, 입지, 커뮤니케이션, 시설이 수련생 만족에 유의한 영향을 미치는 것으로 나타났다.

• 통상정보연구
• /
• 제11권3호
• /
• pp.391-408
• /
• 2009

This study first designates the factors affecting Foreign Direct Investment (FDI) in order to analyze the FDI in Korea, and calculates the Korean FDI index by using various designated variables and by applying Factor Analysis Technique. In addition, it attempts to understand the influence wielded by the foreign investment variables of foreign multinationals on FDI in Korea, by setting to analyze & verify Environmental Factors and the overall model based on FDI in Korea. Through an emprical analysis of USA, Japan, EU, China, as our hypothesis, we could verify that the positive effects(+) among the decisive factors of FDI in Korea include the market size, the mean earning rate of domestic manufacturing industries, and the marketing capacities of foreign corporations, while the negative effects(-) include the ratio of taxation on domestic manufacturing industries. Other FDI factors have various effects on each, so some factors show the same effects as the hypothesis while others show separate effects. In addition, the only nation for which the effects of FDI factors in Korea coincide with the hypothesis completely is the USA, while other nations (such as Japan, EU, China) have some effects that conform to the hypothesis, but other effects do not accord with it.

• 한국경영과학회지
• /
• 제32권2호
• /
• pp.163-175
• /
• 2007

[ $ulcorner$ ]Cost-Effectiveness Analysis$\lrcorner$ has been wifely used to evaluate economic efficiency of R&D projects, but most of cost-effectiveness evaluation systems have some problems such as systematic method for setting and evaluating cost factors, estimation of single effect on each R&D project, and estimation of cross effects among R&D projects. To solve these problems, we have designed a new evaluation indicator called a $ulcorner$Cost-Cross Effect Integration Indicator$lrcorner$ including cross effects developed in this research. The major research findings are summarized as follows : (1) $ulcorner$Coist Estimation Model$lrcorner$, which estimates the cost factors divided into two classes of assembly product and system product and then integrates the total cost values, has been designed. (2) A new method for estimating parameters of cross effects among R&D projects has been developed. (3) $ulcorner$Cross Effects Estimation Model$lrcorner$ to estimate multi-effects and cross effects by completion time among several projects has been designed. (4) $ulcorner$Integration Estimation Indicator$lrcorner$ for setting priority on a project group has been extracted by combination of total cost value and total effect value.

• ETRI Journal
• /
• 제27권2호
• /
• pp.206-218
• /
• 2005

We measure and compare externalities of IT and R&D capital stocks in different Korean industry sectors using inter-industry input-output tables of 1985, 1990, 1995 and 2000. We also compute the multiplier effects that relate to the directions of future economic effects. The key findings are as follows. First, we observed continuous capital deepening in all nine industries over the period of 1985 to 2000. Second, the backward multipliers of IT capital were the highest in the manufacturing industry. As for inter-industry externalities, the indirect backward multipliers, which exclude intra-industry backward multiplier effects within the industry, were also the highest in the manufacturing industry. Third, the forward multiplier effects of IT capital stock were the most substantial in the construction industry during the 1980s and in the manufacturing industry thereafter. Finally, using the transition multiplier matrix reflecting the backward effects of the two capitals in the past, the economic backward effects, especially the external economic effects, are predicted to increase through 2010 among all industries. The above findings suggest that, in order to maximize the forward and backward effects of the ever-increasing IT capital, we need to formulate an industry policy reducing the cost of capital accumulation in the manufacturing industry through improvement in productivity of the IT industry.

• 복식
• /
• 제53권3호
• /
• pp.89-106
• /
• 2003

The purpose of this study is to analyze the expressive effects of Queen Elizabeth I's robes in cinema and also to present two examples of Queen Elizabeth I's robes designed and made based on these expressive effects. To this end, this study wilt first examine Queen Elizabeth I's robes in her portraits according to the visual definers and emblematic meanings. Then on the basis of these knowledges, analyze visual definers and viewing priorities of Queen Elizabeth I's robes in five movies. Thereinafter, these robes will be classified based upon Belong(1998)'s four expressive effects. excitement. calmness, strength and delicacy. Finally, this study will demonstrate calmness and delicacy among four expressive effects through two robes made for the purpose. After analyzing the expressive effects of robes in five Queen Elizabeth I's movies, one can conclude excitement. calmness, strength, and delicacy can be found according to the flow of the story. Since this analysis focuses mainly on one particular person during one Particular period of time, there was a fundamental silhouette prevalent among the Queen's robes which then can be classified into different forms. Moreover, Queen's character in itself embodies authority and grace which. in turn, facilitates the presentation of the four expressive effects along the story line. In conclusion, thorough historical research on the character and the period. in addition to analysis of the visual definer and viewing priorities, is imperative when designing a historical costume.

• Structural Engineering and Mechanics
• /
• 제57권1호
• /
• pp.179-200
• /
• 2016

In this paper the differential transformation method (DTM) is utilized for vibration and buckling analysis of nanotubes in thermal environment while considering the coupled surface and nonlocal effects. The Eringen's nonlocal elasticity theory takes into account the effect of small size while the Gurtin-Murdoch model is used to incorporate the surface effects (SE). The derived governing differential equations are solved by DTM which demonstrated to have high precision and computational efficiency in the vibration analysis of nanobeams. The detailed mathematical derivations are presented and numerical investigations are performed while the emphasis is placed on investigating the effect of thermal loading, small scale and surface effects, mode number, thickness ratio and boundary conditions on the normalized natural frequencies and critical buckling loads of the nanobeams in detail. The results show that the surface effects lead to an increase in natural frequency and critical buckling load of nanotubes. It is explicitly shown that the vibration and buckling of a nanotube is significantly influenced by these effects and the influence of thermal loadings and nonlocal effects are minimal.

• Structural Engineering and Mechanics
• /
• 제10권4호
• /
• pp.371-392
• /
• 2000

Application of "advanced analysis" methods suitable for non-linear analysis and design of steel frame structures permits direct and accurate determination of ultimate system strengths, without resort to simplified elastic methods of analysis and semi-empirical specification equations. However, the application of advanced analysis methods has previously been restricted to steel frames comprising only compact sections that are not influenced by the effects of local buckling. A concentrated plasticity method suitable for practical advanced analysis of steel frame structures comprising non-compact sections is presented in this paper. The pseudo plastic zone method implicitly accounts for the effects of gradual cross-sectional yielding, longitudinal spread of plasticity, initial geometric imperfections, residual stresses, and local buckling. The accuracy and precision of the method for the analysis of steel frames comprising non-compact sections is established by comparison with a comprehensive range of analytical benchmark frame solutions. The pseudo plastic zone method is shown to be more accurate and precise than the conventional individual member design methods based on elastic analysis and specification equations.

• 여성건강간호학회지
• /
• 제24권3호
• /
• pp.243-251
• /
• 2018

Purpose: To determine effects of job-seeking stress on perimenstrual symptoms of female college students with health and non-health related majors and mediating effects of stress coping styles. Methods: Data were collected from 189 female college students who were juniors or seniors. This study was conducted using questionnaires on job-seeking stress, perimenstrual symptoms, and stress coping styles. Data analysis included descriptive statistics, Pearson correlation analysis, and multiple regression analysis using SPSS, version 23.0. Mediation analysis was performed according to the Baron and Kenny method and Sobel test. Results: Job-seeking stress was significantly and positively correlated with perimenstrual symptoms in non-health college students. Passive stress coping styles demonstrated a complete mediating effect on the relationship between job-seeking stress and perimenstrual symptoms of those with non-health related majors (${\beta}=0.31$, p=.002). Such effect was significant (Sobel test; Z=2.06, p=.039). Conclusion: Effects of job-seeking stress on perimenstrual symptoms were mediated by passive stress coping styles of non-health related major students. Based on findings of this study, effective stress cope strategies should be developed considering characteristics of majors to manage perimenstrual symptoms of female college students with high job-seeking stress.

• Computers and Concrete
• /
• 제25권3호
• /
• pp.245-253
• /
• 2020

Vibrational analysis in microtubules is examined based on the nonlocal theory of elasticity. The complete analytical formulas for wave velocity are obtained and the results reveal that the small scale effects can reduce the frequency, especially for large longitudinal wave-vector and large circumferential wave number. It is seen that the small scale effects are more significant for smaller wave length. The methods and results may also support the design and application of nano devices such as micro sound generator etc. The effects of small scale parameters can increase vibrational frequencies of the protein microtubules and cannot be overlooked in the analysis of vibrating phenomena. The results for different modes with nonlocal effect are checked.