• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1995.10a
• /
• pp.154-159
• /
• 1995

In this study, an efficient, yet easy to use, in-situ runout identification scheme by using extended influence coefficient method is presented for active magnetic bearing(AMB) systems. It is shown experimentally that the proposed scheme successfully identifies and eliminates the troublesome runout of the well balanced AMB system in the laboratory so that a high precision spindle system can be achieved, while it is in operation.

• Korean Journal of Psychosomatic Medicine
• /
• v.4 no.2
• /
• pp.182-197
• /
• 1996

For the purpose of examining the relationship between smoking, perceived stress and vulnerability factors, and furthermore suggesting interventions to reduce excessive smoking and prevent nicotine dependency effectively, the questionnaires of perceived stress(stressful experiences), ways of stress coping(passive and active copings), smoking motives, social influence, age, amounts of smoking, and nicotine dependency were administered to smokers among medical students in Chosun university(n=186). 1) As a result of classifying smokers by the types of smoking, the most was a type of smokers to reduce negative emotions and the next in order were addictive smokers, smoker for stimulation, smoker for pleasure, etc. 2) The effects of motive, age, and active coping style were significant, but the effects of perceived stress, passive coping style, and social influence were not significant in average amount of daily smoking. 3) The effects of motive, social influence, and age were significant, but the effects of perceived stress, passive and active coping styles were not significant in the degree of nicotine dependency. To summarize, it is concluded that there were a lot of people who smoke to solve negative emotions, but the direct effects of perceived stress and passive coping style on both average amounts of daily smoking and the degree of nicotine dependency were not significant. On the other hand, motive, age, active coping style, and social influence were proved to be more important variables than the others in explaining college students' smoking.

• Structural Engineering and Mechanics
• /
• v.1 no.1
• /
• pp.119-135
• /
• 1993

The paper presents a generalized optimal active control algorithm for earthquake-resistant structures. The study included the weighting matrix configuration, stability, and time-delays for achieving control effectiveness and optimum solution. The sensitivity of various time-delays in the optimal solution is investigated for which the stability regions are determined. A simplified method for reducing the influence of time-delay on dynamic response is proposed. Numerical examples illustrate that the proposed optimal control algorithm is advantageous over others currently in vogue. Its feedback control law is independent of the time increment, and its weighting matrix can be flexibly selected and adjusted at any time during the operation of the control system. The examples also show that the weighting matrix based on pole placement approach is superior to other weighting matrix configurations for its self-adjustable control effectiveness. Using the time-delay correction method can significantly reduce the influence of time-delays on both structural response and required control force.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.10a
• /
• pp.661-665
• /
• 2005

The muffler reducing the exhaust noise and vibration from the engine influence on the engine performance. Recently the semi-active muffler was developed and adopted to the actual use in consideration of the cost and technical side for noise and vibration. This study is about the recently developed semi-active muffler. This paper attempt to analyze the dynamic stress field on the gate plate by using the finite element methods. According to the analysis of the Exhaust Variable Valve, its spring has the most influence on its operation compare with effects of other components. The design parameters of the Exhaust Variable Valve such as the spring displacement, diameter, coil number, free angle and so forth were used.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.1384-1385
• /
• 2011

This paper presents the active maximum power point tracking(MPPT) control of the photovoltaic(PV) module integrated converter(MIC) system considering the shadow influence. Conventional perturbation and observation(PO) and incremental conductance(IC) are the method finding MPP by the continued self-excitation vibration. The MPPT control is unable to be performed by rapid output change affected by the shadow. To solve this problem, the active MPPT in which the step value changes by output change is presented. In case there are the solar radiation, a temperature and shadow influence, the presented algorithm treats and compares the conventional control algorithm and output error. In addition, the validity of the algorithm is proved through the output error response characteristics.

• The Journal of Information Systems
• /
• v.30 no.3
• /
• pp.1-20
• /
• 2021

Purpose Live streaming commerce refers to the fact that people receive live audio and live video directly over the net. While some e-retailers use Live Streaming as a marketing strategy, the impact of live streaming commerce on customers' reuse intentions is unknown. The purpose of this study is to discuss the impact of live streaming commerce by external environmental factors based on S-O-R theory. Design/methodology/approach In this study, we developed a research model based on the S-O-R theory. Using the questionnaire survey method, consumers who used live streaming commerce on Taobao.com were taken as research subjects. Our research model aims to find out how content attributes, real-time interactions, media characteristics, and situational characteristics as stimulus factors influence consumers' perceptions and thus reuse intentions. Findings The results of the analysis show that external environmental factors have a significant impact on consumer perceptions and that perceived risks and flows can influence consumers' reuse intentions. In addition, we also examined the impact of reuse intentions on consumers' active participation. These results show that live streaming commerce can influence consumer perceptions and behavior in several ways.

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.5 s.182
• /
• pp.137-142
• /
• 2006

The muffler which reduce the exhaust noise and vibration from engine influence on the engine performance. Recently, exhaust variable valve has set up in the muffler controls the backpressure in the exhaust system. And the backpressure variation according to the exhaust variable valve opening has developed the engine performance. First, the preceding of structural analysis is needed and simulation experiment is requested for the study on the design factor to influence on the operation of the exhaust variable valve. In this study, setting up the various variables according to each composition element needed for the structural analysis of the exhaust variable valve, it is experimented the analysis on the influence of each design factor with the calculation of stress distribution and the displacement to cause about the backpressure for the valve through parameter study.

• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.4
• /
• pp.140-146
• /
• 2002

High speed rotating machines can be very sensitive to rotating mass unbalance that is a major source of harmful vibration for many types of rotating machinery. So, the balancing procedure is needed for all high-speed rotating system. To save the time and cost of off-line balancing, many researchers have developed the on-line balancing devices and methods. In this paper, an active balancing device, which is an electro-magnetic type, is developed and the active balancing algorithm using influence coefficient method is also proposed. The active balancing experiment for flexible rotors during operation is performed by an active balancing device. As a result, controlled unbalance responses are below the vibration limit at all rotating speed ranges with critical speed.

• Journal of the Korean Home Economics Association
• /
• v.41 no.8
• /
• pp.179-199
• /
• 2003

This study was intended to probe the scheme for correctly making Korean fashion design known to the world. It is because its suggestion could find out in the current influence of Japanese designer works led to fashion in Europe and the U.S. It can be said that this success was attributed to Japanese high economic growth, increased interests in fashion, increased awareness of the fashion industry, production of designers activity in the world area, systematic and active support of the fashion circles and government for the fashion industry and so on. Korean government has recently begun to attempt to nurture Koreanism or Korean look as world-class fashion. But there are a considerable number of obstacles in making Koreanism or Korean look known to the world due to such several factors as the lack of interests in fashion, the lack of globally active designers, and the like. It is necessary to nurture the fashion industry and educate and train designers for the long-term perspective. In addition, both the government and the fashion circles need to provide for more active and reasonable policy for holding the Korean Fashion Fair, expanding the Seoul Collection to the more global level, opening the way for new designers, and so forth. Furthermore, our academic circles need to make much research on the scheme for the glottalization of Koreanism or Korean look.

• Geomechanics and Engineering
• /
• v.12 no.6
• /
• pp.983-1001
• /
• 2017

The extent by which economy and safety concerns can be addressed in earth retaining structure design depends on the accuracy of the assumed failure surface. Accordingly, this study attempts to investigate and quantify mechanical backfill properties that control failure surface geometry of cohesionless backfills at the active state for translational mode of wall movements. For this purpose, a small scale 1 g physical model study was conducted. The experimental setup simulated the conditions of a backfill behind a laterally translating vertical retaining wall in plane strain conditions. To monitor the influence of dilative behavior on failure surface geometry, model tests were conducted on backfills with different densities corresponding to different dilation angles. Failure surface geometries were identified using particle image velocimetry (PIV) method. Friction and dilation angles of the backfill are calculated as functions of failure stress state and relative density of the backfill using a well-known empirical equation, making it possible to quantify the influence of dilation angle on failure surface geometry. As a result, an empirical equation is proposed to predict active failure surface geometry for cohesionless backfills based on peak dilatancy angle. It is shown that the failure surface geometries calculated using the proposed equation are in good agreement with the identified failure surfaces.