• Proceedings of the KIEE Conference
• /
• 1999.07a
• /
• pp.167-169
• /
• 1999

This paper presents the d-q axis inductances calculations method of Interior Permanent Magnet Synchronous Motor(IPMSM) by using Finite Element(FE) analysis. The inductances of d-q axis in IPMSM, which is the function of current magnitude and phase angle are computed by energy dual method. The appropriateness of the proposed FE analysis has been verified by comparing with experimental results.

• Proceedings of the Korea Society for Simulation Conference
• /
• 2005.11a
• /
• pp.138-143
• /
• 2005

In order to reduce traffic accident, the interaction between drivers and roads should be studied in drivers' behaviour standpoints, and then this must be applied to the establishment of the road design standard. The K-ROADS(KICT-Road Analysis Driving Simulator) was developed to analyze and evaluate the road safety at the project HuRoSAS(Human & Road Safety Analysis System), since 2003. This has two distinct functions. One is the visual system which has 360 degree F.O.V. to reduce a dead angle on black spots as at-grade intersection. The other is the motion system which reproduce high frequency vibration made in irregular road surface and vehicle's motion. The K-ROADS has been used the study on the effect of alternatives of speed hump, and the study on the interior wall design of long tunnel to safety standpoints.

• KIEAE Journal
• /
• v.7 no.5
• /
• pp.41-46
• /
• 2007

The lightshelf system, a horizontal shading and light redirect device, should improve the visual environment by optimal light distributions and intense illumination levels of a interior. This study aims to evaluate the daylighting performance of window integrated lightshelf systems by computer simulations. For the study, the standard office plan is analyzed through the field surveys. And then, the various lightshelf types attached window systems are picked out from existed research results. The max, minimum and average illuminance levels of interiors and illuminance distributions are evaluated by Lightsacpe 3.2 programs based on the installing height, shape type and moving angle of lightshelfs. As results, it is suggested that the optimum lightshelf shapes are the height 1.8m and the width 600mm. Also, in mixed lightshelf, the outside width 600mm, inside width 400 are efficient on indoor daylighting performance.

• 전기의세계
• /
• v.27 no.5
• /
• pp.69-75
• /
• 1978

3 phase induction motor applied in the method of connecting it directly across the line needs large current when it starts. At that time, leakage magnetic pathes of interior of the motor are severely saturated and leakage reactances are decreased because of saturation. Consequently, increased current and raised powerfactor yield increase of starting torque. The author, noticing those phenomena, derived experimentally the raion of decreasing leakage reactance from the fact that when voltage applied to motor is increased under locked condition the magnitude of current and phase angle are varied, and determined tha equations of starting current and starting torque, considering the decrease of leakage reactance by the large starting current. The author calculated the characteristics of Current-Time and Speed-Time with the determined equation at specific load conditions, and compared the values obtained from above calculations with those from circle diagram's method and the practically recorded values at same load conditions. Therefore, the authos got a confidience that the results of the derived theory coincide with the practically measured values more well than circle diagram's results and circle diagram's equation should be modified in order to analize the starting status of a induction motor.

• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.1049-1051
• /
• 2004

This paper presents the analysis and the design of IPMSM for high speed limit with constant torque. The characteristics of IPMSM are calculated by using d-q equivalent circuit having the parameters, such as current phase angle, d-q axis inductances, effective turns. These parameters affect the output characteristics. In this paper, the improved IPMSM to widen the operating speed limit are designed by the results.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.5
• /
• pp.1577-1581
• /
• 2014

This paper presents a method to minimize torque ripple of a V-type IPMSM using the PSO (Particle Swarm Optimization) method with FEM. The proposed algorithm includes one objective function and three design variables for a notch on the surface of a rotor. The simulation model of the V-type IPMSM has 3-phases, 8-poles and 48 slots with 2 notches on the one-pole rotor surface. The arc-angle, length and width of the notch are optimized to minimize the torque ripple of the motor. The cogging torque of the model is reduced by 55.6% and the torque ripple is decreased by 15.5 %. Also, the efficiency of the motor is increased by 15.5 %.

• Steel and Composite Structures
• /
• v.32 no.1
• /
• pp.37-57
• /
• 2019

This paper presents experimental and analytical studies to evaluate the cyclic behaviour of Circular Reinforced Concrete column Steel beam (CRCS) connections. Two 3/4-scale CRCS specimens are tested under quasi-static reversed cyclic loading. Specimens were strengthened with a tube plate (TP) and a steel doubler plate (SDP). Furthermore; nine interior beam-through type RCS connections are simulated using nonlinear three-dimensional finite element method using ABAQUS software and are verified with experimental results. The results revealed that using the TP improves the performance of the panel zone by providing better confinement to the concrete. Utilizing the TP at the panel zone may absorb and distribute stress in this region. Results demonstrate that TP can be used instead of SDP. Test records indicate that specimens with TP, with and without SDP maintained their maximum strength up to 4% drift angle, satisfying the recommendation given by AISC341-2016 for composite special moment-resisting frames.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.25 no.6
• /
• pp.275-281
• /
• 2021

In this study, algorithms for analyzing the torsion of buildings under earthquake excitation are developed. The algorithm and formulations to account for the torsional angle are verified by analyzing the seismic acceleration time history data. The method was applied to the reference buildings to examine their operation and usability. The reference application demonstrated that the noise-canceling scheme successfully overcame various obstacles in the field measurements. The developed method is expected to be used as a tool to support a loss assessment system for determining the direction and priority of disaster response in the event of an earthquake.

• Proceedings of the KIPE Conference
• /
• 2020.08a
• /
• pp.248-250
• /
• 2020

본 논문은 토크 각 기반 Direct Self Control (DSC) 기법의 매입형 영구자석 동기전동기(Interior Permanent Magnet Synchronous Motor, IPMSM) 고속 운전 방법을 제안한다. DSC 기법은 철도차량용 유도전동기에 처음으로 적용되었으며, 토크 동특성이 우수하고 약자속 영역에서 6-스텝 운전의 구현이 유리한 장점이 있다. 기존 DSC 기법으로 IPMSM을 구동하는 경우 토크 동특성이 우수하지만, 약자속 영역에서 6-스텝 운전의 성능이 떨어지는 단점이 있다. 본 논문에서는 지령 토크 각을 이용한 DSC 기법의 IPMSM 고속 운전 방법을 제안한다. 제안하는 방법의 타당성은 시뮬레이션을 통해 검증한다.

• Korean Institute of Interior Design Journal
• /
• v.25 no.1
• /
• pp.73-80
• /
• 2016

Street is the most fundamental component of city and place to promote diverse actions of people. Pedestrians gaze at various street environments. A visual gaze means that there are interesting elements and these elements need to be preferentially improved in the street environment improvement project. Therefore, this study aims to set up the priorities of street environment components by analyzing eye movements from a pedestrian perspective. In this study, street environment components were classified into road, street facility, building(facade) and sky and as street environment images, three "Streets of Youth" situated in Gwangbok-ro, Seomyeon and Busan University of Busan were selected. The experiment targeted 30 males and females in their twenties to forties. After setting the angle of sight through a calibration test, an eye-tracking experiment regarding the three images was conducted. Lastly, the subjects were asked to fill in questionnaires. The following three conclusions were obtained from the results of the eye-tracking experiment and the survey. First, building was the top priority of street environment components and it was followed by street facility, road and sky. Second, as components to be regarded as important, fast 'Sequence', many 'Fixation Counts' and 'Visit Counts', short 'Time to First Fixation' and long 'Fixation Duration' and 'Visit Duration' were preferred. Third, after voluntary eye movements, the subjects recognized the objects with the highest gaze frequency and the lowest gaze frequency.