• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.211-213
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• 2007

The electrical parameters are used to calculate gains in the current regulator as well as to determine the reference currents of speed controller in various control strategies of Synchronous Reluctance Motors (SynRMs). Many methods of measuring or estimating the electrical parameters of SynRM have been proposed by other authors. But almost papers only measure or estimate in the limited conditions without fully considering the effects of inverter, connecting wire and magnetic saturation. The parameter results are usually different from the real system parameters. The drive performance, therefore, can not be good if using inaccurate parameters. In this paper, several methods used to measure the electrical parameters are introduced. The first method is LCR meter. And then, a method determining inductances by measuring AC current and voltage from AC power supply is presented. A new method with high reliability is proposed to measure the electrical parameters of SynRM. The experiment results verify the effectiveness of the new proposed method.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.4
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• pp.126-137
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• 1994

Performance management of computer networks is intended to improve a given network performance in order for more efficient information exchange between subsystems of an integrated large-scale system. Importance of perfomance management is growing as many functions of the large- scale system depend on the quality of communication services provided by the network. The role of performance management is to manipulate the adjustable protocol parameters on line so that the network can adapt itself to a dynamic environment. This can be divided into two subtasks : performance evaluation to find how changes in protocol parameters affect the network performance and decision making to determine the magnitude and direction of parameter adjustment. This paper is the first part of the two papers focusing on conceptual design, development, and evaluation of performance management for token bus networks. This paper specifically deals with the task of performance evaluation which utilizes the principle of perturbation analysis of discrete event dynamic systems. The developed algorithm can estimate the network performance under a perturbed protocol parameter setting from observations of the network operations under a nominal parameter setting.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1993.10a
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• pp.5-18
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• 1993

This paper reports the recent trends in active vibration control in Japan, especially, based on papers selected in the Proceedings of First International Conference on Motion and Vibration Control (1st MOVIC) held at Yokohama, Japan on Sept.7-11, 1992. Firstly, it classifiers vibration control methods and vibration controllers, especially active dynamic absorbers which are widely used in mechanical and civil engineering. Secondly, it covers basic problems in the control of vibration of flexible structures such as formulating a reduced-order model required for designing vibration controller, proper arranging of sensors and actuators, and preventing of spillover instability. Finally, the practical use of control theories such as LQ control theory, $H^{\infty}$ control theory, neural network theory, and other topics are discussed..

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.10a
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• pp.98-103
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• 1996

Elimination of squeal noise generated during brake application is an important task for the improvement of comforts in vehicles. In this paper, the structure of the wet brake and its operation are described first, and the cause of the noise is analyzed by identifying how the factors such as torque, speed, oil pressure, lubricant, and friction material affect the noise. To verify the mechanism of generation of the noise, several experiments of brake applications are executed, Based upon the review on the technical papers and the results from the experiments, several solutions to reduce the noise, available in real applications, are suggested, and the feasibilities of them are confirmed through the applications to the current system.

• International Journal of Knowledge Content Development & Technology
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• v.7 no.2
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• pp.53-83
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• 2017

This research aims at identifying through literature analysis the extent of past research related to the protection of personal information and privacy of library users. This study was conducted in 3 stages of literature analysis suggested by other researchers, including Powell (2005). First, I found and collected literature related to personal information and library user privacy. Second, I reviewed the collected literature and identified detailed subjects and core concepts. Third, I analyzed the core subjects, main discussion points, and related examples shown in those papers divided into 7 subgroups. I examine library privacy from various angles through literature analysis, and the results of this paper would be useful for establishing library privacy policies and developing guidelines for librarians.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05a
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• pp.21-27
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• 1996

KAERI has recently developed the nuclear design code MASTER for the application to reactor physics analyses for pressurized water reactors. Its neutronics model solves the space-time dependent neutron diffusion equations with the advanced nodal methods. The major calculation categories of MASTER consist of microscopic depletion, steady-state and transient solution, xenon dynamics, adjoint solution and pin power and burnup reconstruction. The MASTER validation analyses, which are in progress aiming to submit the Uncertainty Topical Report to KINS in the first half of 1996, include global reactivity calculations and detailed pin-by-pin power distributions as well as in-core detector reaction rate calculations. The objective of this paper is to give an overall description of the CASMO/MASTER code system whose verification results are in details presented in the separate papers.

• Kyungpook Mathematical Journal
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• v.60 no.4
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• pp.853-867
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• 2020

The aim of this study was to analyze the momentum and heat transfer of a rotating nanofluid with conducting spherical dust particles. The fluid flows over a stretching surface under the influence of an external magnetic field. By applying similarity transformations, the governing partial differential equations were trans-formed into nonlinear coupled ordinary differential equations. These equations were solved with the built-in function bvp4c in MATLAB. Moreover, the effects of the rotation parameter ω, magnetic field parameter M, mass concentration of the dust particles α, and volume fraction of the nano particles 𝜙, on the velocity and temperature profiles of the fluid and dust particles were considered. The results agree well with those in published papers. According to the result the hikes in the rotation parameter ω decrease the local Nusselt number, and the increasing volume fraction of the nano particles 𝜙 increases the local Nusselt number. Moreover the friction factor along the x and y axes increases with increasing volume fraction of the nano particles 𝜙.

• Korean journal of aerospace and environmental medicine
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• v.31 no.2
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• pp.31-32
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• 2021

In Vol. 31, No. 2, our journal prepared a review article, two original papers, and three case reports. First, autonomous systems are increasingly being introduced in aircraft systems. Therefore, it is crucial that flight crews are trained to adapt and handle these autonomous systems better. Consequently, we discussed crew resource management for handling autonomous systems. The fatigue of aviation workers is one of the biggest threats to aviation safety. Therefore, we analyzed the degree of fatigue in commercial aircraft pilots and evaluated the relationship between fatigue and their workload and the effect of fatigue on sleep. Since obesity has a significant impact on the health of aviation workers, we also comparatively analyzed the prevalence of obesity in Korea and Japan based on the data from the National Health and Nutrition Examination Survey. We defined cases that are difficult for aviation medical examiners to evaluate. This issue included cases of peripheral dizziness and tinnitus, cases of atopic dermatitis treated with biological agents, and cases of malignant tumors.

• Korean journal of aerospace and environmental medicine
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• v.30 no.1
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• pp.1-2
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• 2020

In commemoration of Vol. 30, Issue 1, our journal prepares four review articles and two original papers. The first review article provides guidelines for medical treatment for emergencies in an aircraft furing flight. This guideline addresses the resources and medical equipment available to physicians on board, common medical conditions, how to deal with them, including legal issues. The second review article covers historically meaningful animals that have contributed to aerospace research and the role of a veterinarian. The third one describes cardiovascular, musculoskeletal, and vestibular physiological effects of microgravity on the human body. As we are about to enter an aging society, the fourth review article introduces guidelines for safe overseas travel for senior passengers. The role of the aviation medical examiner is to maintain aircrew's health and to help them work long and healthy. In this regard, Choi et al. analyzed the physical examination data and sick leave data of an airline. Han et al. investigated the aerospace medical examination data of the Republic of Korea and suggested a solution to some common health problems of the crew.

• Steel and Composite Structures
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• v.47 no.6
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• pp.795-811
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• 2023

When studying the resonance problem of nanoplates, the existing papers do not consider the influences of geometric nonlinearity and initial geometric imperfection, so this paper is to fill this gap. In this paper, based on the nonlocal strain gradient theory (NSGT), the nonlinear resonances of functionally graded (FG) nanoplates with initial geometric imperfection under different boundary conditions are established. In order to consider the small size effect of plates, nonlocal parameters and strain gradient parameters are introduced to expand the assumptions of the first-order shear deformation theory. Subsequently, the equations of motion are derived using the Euler-Lagrange principle and solved with the help of perturbation method. In addition, the effects of initial geometrical imperfection, functionally graded index, strain gradient parameter, nonlocal parameter and porosity on the nonlinear forced vibration behavior of nanoplates under different boundary conditions are discussed.