• Title/Summary/Keyword: Power Effect

Search Result 10,606, Processing Time 0.037 seconds

Numerical Study on the Power-on Effect of a Pusher-propeller Aircraft using CFD (CFD를 이용한 추진식 프로펠러 항공기의 Power-on 효과 해석)

  • Cho, Jeong-Hyun;Cho, Jin-Soo
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.42 no.1
    • /
    • pp.59-66
    • /
    • 2014
  • In the case of a propeller-driven aircraft, power-on effect generated by the propeller has a strong influence on the performance and the stability of an aircraft directly and indirectly. A numerical study on the power-on effect has been performed using the CFD based on the multiple reference frame and sliding mesh model. The power-on effect increases the overall lift and the maximum lift of the aircraft. In addition to lift increment, power-on effect delays the stall of the aircraft. On the other hand, the power-on effect increases the drag significantly and consequently decreases the lift-to-drag ratio of the aircraft. Furthermore, the power-on effect decreases the nose-down pitching moment and consequently decreases the longitudinal static stability of the aircraft. It is expected that the analysis results presented and discussed in this report will be used as an important material for analyzing the aircraft performance and stability and will contribute the development of the propeller-driven aircraft with the pusher propeller.

A Proposal of Combat Power Measurement Model of Army Warfare Information System Using Network Power based on Social Network Analysis (SNA 기반 네트워크 파워를 이용한 지상전장정보체계 전투력 효과측정 모델제안)

  • Jung, Chi-Young;Lee, Jae-Yeong
    • Journal of the Korean Operations Research and Management Science Society
    • /
    • v.36 no.4
    • /
    • pp.1-16
    • /
    • 2011
  • It is important not only to introduce the C4I(Command and Control, Communication, Computer, Intelligence) system for realizing the NCW(Network Centric Warfare) but also to evaluate the synergistic effect by the C4I system. However, the study effort for evaluating the system's synergistic effect is insufficient compared with introducing the system. Therefore, in this paper, we proposed a model that measures the synergistic effect of combat power by the warfare information system. To measure the synergistic effect of warfare information system, the network power must be considered, so we also proposed a new methodology for measurement of network power based on SNA(Social Network Analysis), not Metcalfe's law. A model we proposed is a model that measures the raised combat power by the network effectiveness. The methodology and model we proposed in this paper will be used usefully to analyze the practical effect of constructing future warfare information system.

승용차유통경로에서 딜러의 협력, 갈등, 성과 간의 관계에 관한 연구

  • 계도원
    • Journal of Distribution Research
    • /
    • v.1 no.1
    • /
    • pp.109-127
    • /
    • 1996
  • The purpose of this study was to represent hypotheses of the interrelationship of the level of cooperation, conflict, and performance and to report the findings testing the hypotheses in car channels. This study provides some general guidance toward better cooperation, conflict, and performance management. The results indicate that noncoercive bases of power and dependence hale a positive effect on cooperation, while the proposed inverse relationship between coercive bases of power and cooperation is not statistically significant. Coercive bases of power have a positive effect on conflict, while conflict is not statistically significant for noncoercive bases of power, dependence, and cooperation. Finally, cooperation has a positive effect on dealer performance, but conflict has a negative effect on dealer performance.

  • PDF

The Effect of Wrist Stretching on Grasping Power and Musculoskeletal Disorders (손목 스트레칭이 파악력과 근골격계질환에 미치는 영향)

  • You, Heon-Jong
    • Journal of the Korea Safety Management & Science
    • /
    • v.24 no.3
    • /
    • pp.47-53
    • /
    • 2022
  • In order to conduct a study on the importance of the wrist joint, which causes a lot of pain among middle-aged people, in relation to work related to musculoskeletal disorders, the effect of stretching on grasping power was studied. In order to compare the grasping power of the wrist for middle-aged people in their 50s, the experiment was conducted by comparing before and after the wrist joint motion stretching. According to the experimental results of wrist gripping power for the control group and the experiment group on wrist gripping power, it was investigated that stretching did not change much in increasing wrist gripping power, but stretching application had an effect on wrist gripping power. In terms of preventing musculoskeletal accidents, reducing pain due to degenerative diseases, and preventing accidents, stretching seems to have an effect when approaching, so it is considered that continuous stretching before and after work is necessary. Therefore, it is suggested that stretching time secured quantitatively through safety and health education before work is necessary.

Stochastic Stability Analysis of the Power System Incorporating Wind Power using Measurement Wind Data

  • Parinya, Panom;Sangswang, Anawach;Kirtikara, Krissanapong;Chenvidhya, Dhirayut
    • Journal of Electrical Engineering and Technology
    • /
    • v.13 no.3
    • /
    • pp.1110-1122
    • /
    • 2018
  • This paper proposes an alternative method to evaluate the effect of wind power to the power system stability with small disturbance. Alternatively, available techniques for stability analysis of a power system based on deterministic methods are less accurate for high penetration of wind power. Numerical simulations of random behaviors are computationally expensive. A stochastic stability index (SSI) is proposed for the power system stability evaluation based on the theory of stochastic stability and energy function, specifically the stochastic derivative of the relative well-defined energy function and the critical energy. The SSI is implemented on the modified nine-bus system including wind turbines under different conditions. A doubly-fed induction generator (DFIG) wind turbine is characterized and modeled using measured wind data from several sites in Thailand. Each of the obtained wind power data is analyzed. The wind power effect is modeled considering the aggregated effect of wind turbines. With the proposed method, the system behavior is properly predicted and the stability is quantitatively evaluated with less computational effort compared with conventional numerical simulation methods.

An Empirical Study on the Influence of Hypersensitiveness in Accident Reports and Usefulness on Receptiveness of Atomic Power Generation

  • Rho, Hyung-Jin
    • Journal of the Korea Society of Computer and Information
    • /
    • v.21 no.4
    • /
    • pp.115-121
    • /
    • 2016
  • The purpose of this paper is to study the influence of hypersensitiveness in accident reports and usefulness on admission of atomic power generation. By the result of study we can look forward to understanding obstacles and promotion factors in constructing atomic power plants. The results of hypothesis testing can be summarized as follows: First, the hypothesis that hypersensitiveness in accident reports has a plus effect on reliability is accepted. Secondly, the hypothesis that hypersensitiveness in accident reports has a plus effect on anxiety is accepted. Thirdly, the hypothesis that reliability has a plus effect on anxiety is accepted. Fourthly, the hypothesis that reliability has a minus effect on receptiveness is accepted. Fifthly, the hypothesis that anxiety has a minus effect on receptiveness is accepted. Sixthly, the hypothesis that usefulness has a minus effect on necessity is accepted. Seventhly, the hypothesis that usefulness has a plus effect on receptiveness is rejected. Eighthly, the hypothesis that necessity has a minus effect on receptiveness is accepted.

Determining the Warming Effect Induced by Photovoltaic Power Plants in neighboring Region Using an Analytical Model (해석학적 모델을 이용한 태양광 발전소 주변 지역의 기온 상승 추정 연구)

  • Kim, Hae-Dong;Huh, Kyong-Chun;Kim, Ji-Hye
    • Journal of Environmental Science International
    • /
    • v.27 no.3
    • /
    • pp.227-231
    • /
    • 2018
  • We studied the warming effect induced by Photovoltaic(PV) power plants in rural areas during summer daytime using a simple analytical urban meteorological model. This analysis was based on observed meteorological elements and the capacity of the PV power plant was 10 MWp. The major axis length of the PV power plant was assumed to be 1km. Data of the necessary meteorological elements were obtained from a special meteorological observation campaign established for a over a PV power plant. We assumed that the wind flowed along the major axis of the PV power plant(1 km). As a result, the air temperature on the downwind side of the PV power plant was estimated to invrease by about $0.47^{\circ}C$.

The Effect of Power Sources of Department Store and Fashion Company, and Salesperson's Job Consciousness on Job Satisfaction in the Middle Management System of Department Store (백화점 중간관리 형태에서 백화점 및 패션업체의 권력원천과 판매원의 직업의식이 직무만족에 미치는 영향)

  • Lee, Hyun-Jin;Choo, Tae-Gue
    • Fashion & Textile Research Journal
    • /
    • v.14 no.2
    • /
    • pp.230-241
    • /
    • 2012
  • The purpose of this study was to examine the effect of power sources of department store and fashion company, and salesperson's job consciousness on job satisfaction in the middle management system of department store. Questionnaire data from 193 salespeople in the middle management of department store were analyzed by reliability analysis, factor analysis, correlation analysis, multiple regression analysis, hierarchical regression analysis. The results of this study were as follows: First, coercive power, informational and expert power, and referent power of department store had significant effects on job satisfaction. The coercive power of department store had a negative influence on job satisfaction, while informational and expert power, and referent power of department store had a positive influence on job satisfaction. Second, referent power, expert power, reward power, coercive power of fashion company had a positive influence on job satisfaction. Third, referent power of department store had a greater influence on job satisfaction than other power sources. Fourth, job commitment and pride, prospect awareness had a positive influence on job satisfaction, while professional self-awareness had no effect on job satisfaction.

The Effect of Power Type within Supply Chain on the Information Capability: Perspective of CSV Value Creation (공급사슬 내의 파워유형이 정보역량에 미치는 영향: CSV 가치창출 관점)

  • Park, Kwang-O;Chang, Hwal-Sik;Jung, Dae-Hyun
    • The Journal of Information Systems
    • /
    • v.27 no.3
    • /
    • pp.1-24
    • /
    • 2018
  • Purpose The purpose of this study is to attempt to incorporate power theory to evaluate information capability of SCM adopters. Therefore, this study focuses on the relationship of information sharing, partnership quality, and information capacity according to the power intensity of the variables of SCM. and CSV value creation. Design/methodology/approach The questionnaire of SCM builder was conducted and 302 samples were analyzed. Based on the theoretical background of power and information capacity, we set up a structural equation model. Hypothesis testing and statistical analysis were done through AMOS and SPSS. Findings First, it shows that the compensation power among the constrained power has a positive effect on the partnership quality, and the legitimacy power has the positive influence only on the information sharing. Compulsive power, compensation, and legitimacy, which are generally restrictive powers, may reduce the quality of information sharing and partnership, but the results of this study are rather higher. Second, both non-binding power expertise and criterion have a positive effect on information sharing and partnership quality. Third, information sharing has a positive effect on partnership quality. Supporting a number of research results, it is well reflected in SCM attributes where interdependence is important. Fourth, information sharing and partnership quality have a positive effect on information capacity. Information literacy has become an essential element in modern management. Fifth, the enhancement of CSV value creation plays a role of a controlling variable to further strengthen information sharing through non - binding power attribute, expertise and conformity. In addition, the strengthening of CSV value creation has been shown to play a role as a controlling variable to further strengthen the quality of partnership through the non-binding power attribution, but expertise has been rejected.