• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.4
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• pp.265-272
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• 2011

The electrical load profiles of end-users must be analysed properly to introduce distributed generation system efficiently. In this study, numerical simulation for predicting a residential electrical load profile was developed to satisfy categorized electricity consumption range. We applied bottom-up approach to compose electrical load profile by using data from official reports and statistics. The electrical load profile produced from the simulation predicted peak times of public report accurately and agreed well with the standard residential electrical load profile of official reports within average error of 16.2%.

• Transactions of the Society of Information Storage Systems
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• v.2 no.2
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• pp.150-155
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• 2006

Vertical L/UL (Load/Unload) velocity is very important parameter to determine the L/UL performance, and the vertical velocity is determined by the actuator velocity and the ramp profile. However, it is not easy to precisely control the actuator rotating velocity during the L/UL process. Especially in emergency parking, servo system doesn't operate, it is impossible to control an actuator velocity. Then, the vertical unloading velocity depends on only ramp profile. The ramp height and the sliding length for L/UL process in SFF (Small Form Factor) HDD are restricted due to slimness and small media. For these reasons, it is very difficult to design the ramp profile in SFF HDD. Therefore, this study analyzes the unloading dynamic characteristics for various ramp profiles and makes the thesis for ramp profile design.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.8
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• pp.13-19
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• 2010

A design method of railway wheel profile with objective function of equivalent conicity considering wheel dimension constraint, two points contact problem between wheel and rail was proposed. New design method shows good results. New wheel profile generated from optimization process shows better dynamic performance compared with initial profile as the purpose of wheel profile design. And to verify the design method with testing the stability of new wheel profile, we conducted a critical speed test for new wheel profile using scale model applied scaling method of railway vehicle dynamics. The result of critical speed test show good agreement with that of numerical analysis. From the above results, it is seen that the design method with objective function of equivalent conicity is feasible and it could be applied to design new wheel profile efficiently.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.145-155
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• 2020

Since Campbell (1990) proposed multidimensionality of job performance, unlike the single structure of traditional job performance, it has been largely classified as task performance, contextual performance, and counterproductive work behavior. The objective of this study is to validate the threecriteria currently considered major aspects of job performance, to identify different types of performance based on three dimensions, and to compare the power of personality factors among performance types. A total of 681 employees working at various organizations participated in an on-line survey. The survey included boththe exploratory and confirmatory factor analyses. A 3-factor job performance model consisting of three dimensions was also included. The relationships between performance dimensions and personality factors differedby dimensions of performance, supporting the validity of the 3-factor structure of performance.The results of the Latent Profile Analysis identified four types of performance: exemplary, moderately conscientious moderate, and conscientious, butlow.. The Multinomial logistic regression analysis showed each type differed significantly according to the predictors of personality variables. In conclusion, implications and limitations of the study were noted.

• Journal of Korea Multimedia Society
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• v.10 no.8
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• pp.1078-1091
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• 2007

This paper proposes the system to manage profiles effectively that are necessary for content adaptation services. The proposed profiles for providing content adaptation services are used in the various services. However, currently, there are lack of the interoperability in profiles due to the different configuration, which is affected by different services. The service providers also spend a lot of operating costs by operating profiles respectively. To solve theses problems, the system which can integrate and manage the various kinds of the profiles is necessary. Based on profile services architecture and the previous profile research to the necessary functions for the proposed integrated management system of profile are derived. The proposed integrated management system of profile supports also the functions such as receiving, processing, saying, managing, providing and supports profiles that are made of RDF form and comply with the CC/PP specification. The metadata constitution technique and dynamic technique for effective content adaptation also are applied. As a result of performance evaluation the proposed techniques improve the performance 4% compared with the previous techniques.

• Journal of Digital Contents Society
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• v.7 no.1
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• pp.25-33
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• 2006

As becoming the age of ubiquitous, there are many discussion and publication for standards to express platform profile. These various platform profiles have some problems. The solve these problems, we propose and develop a new posting mechanism which improve the performance of contents adaptation engine by simplifying platform profile and processing various type of platform profiles; we introduce the way to integrate different profiles to solve nut to recognize the profile which is used by different adaptation system and simplify platform profile by grouping the similar attributes of platform profiles. Proposed system can processing different profiles and also the system overhead to processing a profile and creating a dynamic profile has reduced. As a result overall performance of content adaptation system has increased.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1991.11a
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• pp.14-21
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• 1991

The performance of finite journal bearing operating in turbulent regime was experimentally investigated. In order to obtain experimental data contained operating conditions(thermal deformation etc.) of bearing, this study measured the pressure and the film thickness with sensors mounted on the journal. And, the continuous pressure profile and the film thickness profile were obtained.

• Tribology and Lubricants
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• v.8 no.1
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• pp.44-47
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• 1992

The performance of finite journal bearing operating in turbulent regime was investigated experimentally. In order to obtain experimental data containing surrounding conditions (thermal deformation, machining error etc.) of journal bearing, this study mounted a pressure sensor and a gap sensor on the journal. The data for continuous pressure profile and continuous film thickness profile were presented in this paper.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.10
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• pp.1110-1118
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• 2012

In this study, for reducing the residual vibration in high speed motion control stage, an improved 5th order polynomial motion profile was developed. When a stage is moving, the current through the motor coils has the same profile of input motion profile of acceleration, therefore the characteristics of the acceleration input profile directly affect on the performance of the amplifier that includes the current control loop. Commonly low cost amplifier and motor has a narrow current control bandwidth, therefore the proposed algorithm was designed based on this practical constraint. Simulation and experimental results showed that the proposed algorithm clearly has low residual vibration characteristics than conventional 5th order polynomial motion profile on the same drive condition.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.5
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• pp.546-551
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• 2016

The objective of this study is to investigate the response delays between piezo-stack actuator and the displacement magnifier of jetting dispenser and to reduce its falling time in terms of displacement optimization. The dispenser is driven by the dual piezo-stack actuators with a hinge lever mechanism to precisely control flow rate of the working fluid (3000 cP). It is commonly found that piezo actuator-driven jetting dispensers involving viscous working fluids have displacement optimization problem for ideal performance. The response delay of the system is caused by the phenomenon that the displacement magnifier cannot exactly follow the motion of the piezo actuators. The response delay may lower the performance of the system due to the inaccurate discharge of working fluid or even damages to the system itself due to inharmonious motion of piezo actuators with lever system. To reduce its response delay, a new displacement profile obtained from displacement optimization is suggested; its performance is tested through finite element analysis; and experiments are carried out to verify the performance of the obtained displacement profile.