• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.31-33
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• 2002

This paper is presents dynamic analysis of slotless PM linear synchronous motor using 3-D analytical method and improvement of controllability using PI control system. In oredr to calculate dynamic characteristic, back-EMF waveform and inductance are caculated by PM's magnetic field and winding's magnetic filed respectively. PMLSM simulated by PI control system.

• Journal of the Korean Magnetics Society
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• v.25 no.6
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• pp.198-202
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• 2015

This s paper presents characteristics Analysis of Outer Rotor type BLDC Motor. To reduce the cogging torque and to make the high back EMF constant of the motor, Not only magnetization directions of a permanent magnet are investigated, but also a tooth chamfer of a stator is optimized. The design and analysis results are verified with experimental results.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.165-167
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• 1997

This paper centers on a method which can reduce calculating time and maintain accuracy of whole model FE analysis with one pole model for short secondary Permanent Magnet Linear Synchronous Motor(PMLSM). We use one pole model which considers the number of pole of stator and mover respectively in order to replace whole model to one pole model and calculate flux linkage and back e.m.f. with accuracy. Also we verify the validity of proposed method with comparision of results of whole and one pole model.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.322-324
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• 1998

This paper describes the characteristics analysis of surface permanent magnet linear synchronous motor with conductive sheet secondary using time-stepped finite element method. The detent force, normal force, back-emf and dynamic characteristics as speed, thrust and current are described.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.5
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• pp.361-367
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• 2004

This paper describes design of an algorithm for analyzing human activity using body-fixed 3-axis accelerometer in the small of the back. In the first step, we distinguish static and dynamic activity period using AC signal analysis. Then five postures were classified by applying the threshold in DC signal corresponding to the static activity period. Also, after comparison of average power and taking negative peak signal in the dynamic activity period, the four dynamic activities were classified by adaptive threshold method. To evaluate the performance of the proposed algorithm, the measured signals obtained from six subjects were applied to the proposed algorithm and the results were compared with the simultaneously measured video data. As a result, the activity classification rate of 95.7％ on average was obtained. Overall results show that the proposed classification algorithm has a possibility to be used to analyze the static and dynamic physical activity.

• Nuclear Engineering and Technology
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• v.53 no.1
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• pp.44-60
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• 2021

In this paper, we validate the decay heat calculation capability via a two-step method to analyze spent nuclear fuel (SNF) discharged from pressurized water reactors (PWRs). The calculation method is implemented with a lattice code STREAM and a nodal diffusion code RAST-K. One of the features of this method is the direct consideration of three-dimensional (3D) core simulation conditions with the advantage of a short simulation time. Other features include the prediction of the isotope inventory by Lagrange non-linear interpolation and the use of power history correction factors. The validation is performed with 58 decay heat measurements of 48 fuel assemblies (FAs) discharged from five PWRs operated in Sweden and the United States. These realistic benchmarks cover the discharge burnup range up to 51 GWd/MTU, 23.2 years of cooling time, and spanning an initial uranium enrichment range of 2.100-4.005 wt percent. The SNF analysis capability of STREAM is also employed in the code-to-code comparison. Compared to the measurements, the validation results of the FA calculation with RAST-K are within ±4%, and the pin-wise results are within ±4.3%. This paper successfully demonstrates that the developed decay heat calculation method can perform SNF back-end cycle analyses.

• The Journal of the Korea Contents Association
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• v.11 no.5
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• pp.224-232
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• 2011

The purpose of this study was to test the reliability and validity of the Korean version of the fear of daily activities questionnaire (FDAQ) for low back pain patients. Seventy-three subjects with low back pain were participated in this study. The subjects completed ten standardized self-administered questionnaires that measure fear of specific daily activities. The reliability of the acquired data was determined by the intra-class correlation coefficient (ICC) and the Cronbach's ${\alpha}$ for internal consistency. Constructive validity was analyzed by factor analysis, and concurrent validity was acquired from comparison FDAQ scores to the visual analogue scale (VAS) and Oswestry disability index (ODI) scores. The test-retest reliability of the Korean version of the FDAQ showed good ICC (2,1)= 0.96 (95%CI 0.94.0.98) and Cronbach's alpha value was 0.93. Factor analysis suggested two factors solution consisting of spinal loading and spinal movement/posture, it explained 76.1% of the total variance. The concurrent validity was moderately related with pain and disability. Therefore, the Korean version of the FDAQ is a useful method for measuring the fear of daily activities of patients with low back pain.

• Journal of the Korean Society of Clothing and Textiles
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• v.15 no.2 s.38
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• pp.151-162
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• 1991

The purpose of this study was to examine the point at issue unfitness and unclassification in figures for clothing construction. Comparing measurements of 3 sold figures and physical body by Suck·Go method and 19 items were selected. These items were acquired by factor analysis and cluster analysis an measurements of 200 women in twenties. The results were as follows; 1. Comparison between measurement of figures and physical body; There was not so much difference among figures, but significant difference between figures and physical body. 2. Comparison between measurement of surface area of figures and physical body; There was similar to each figure, but significant difference between figures and physical body. Mostly, figures were bigger than physical body in front parts but smaller in back parts. 3. There were 8 items selected by factor analysis; That is bust girth, waist girth, hip girth, neck base girth, posterior waist length, bust point length, chest breadth and armscye girth. 4. There were 7 clusters selected by cluster analysis.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.9
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• pp.28-35
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• 1999

In this study, investigation of transient knock characteristics in a spark-ignition engine has been carried out. The universal knock threshold values were found by a DFDD method and a NSDBP method which is a non-dimensional version of the SDBP method. Also modified NSDBP method could be used for transient knock detection. In a commercial ECU , spark timing was retarded from the steady -state spark timing during rapid throttle opening to avoid uncomfortable feeling and knock. Knock usually occurred just after the start of rapid throttle opening when spark timing was set, as values for the steady state condition. We found that air/fuel ratio deeply involved with the knock during transient condition. Due to the difference of initial heat release rate, knock occurred more easily at rich air/fuel ratio than at lean air/fuel ratio.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.933-935
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• 2001

This paper presents a calculating method for inductance of the Switched Reluctance Motor(SRM) for torque characteristics and driving by analytical model. The approaches for calculating inductance have taken vary from detailed finite element analysis(FEA) and Fitting method in magnetization curves using complex nonlinear magnetic circuit models. But those methods have not satisfactory approach for machine performance calculations, because of having a long time and remodeling for analyses, therefore thus an alternative approach is required. So it is suggested simply calculating method of the inductance based on designed data of machinery by analytical model in unaligned and aligned rotor. In order to prove the calculating, there are compare with analytical FEM, direct measurement, this method, and simulation. The compared result is shown to obtain good accuracy.