• Journal of Electrical Engineering and Technology
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• 제8권6호
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• pp.1345-1351
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• 2013

Variable iron loss as function of current phase angle of Interior Permanent Magnet Synchronous Motor(IPMSM) was calculated through Curve Fitting Method(CFM). Also, a magnetic flux density distribution of iron core according to current phase angle was analyzed, and an iron loss calculation was performed including harmonic distortion. The experiment was performed by production of non-magnetizing model for the separation of mechanical loss, and the iron loss was calculated by the measurement of input using power analyzer and output power using dynamometer. Some error was generated between experimental results and calculation value, but an iron loss diminution according to current phase angle followed a same pattern. So, errors were generated by measurement, vibration, noise, harmonic distortion loss, etc.

• Journal of Periodontal and Implant Science
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• 제32권3호
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• pp.539-554
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• 2002

It has been approximately 40 years since $Br{{\aa}}nemark$ first introduced osseo-integration for implants in the early 1960s. Unlike crown and bridge or denture treatment, implant treatment helps preserve existing bone and improve masticatory functions. Thus, the awareness of implant treatment has grown rapidly among dentists and patients alike in Korea, as it becomes a widely accepted treatment. The following results on patients type and implant distribution were compiled from 1814 implant cases of 640 patients treated at the periodontal dept. of Y University Hospital during 1992 to 2001. 1. There are no dissimilarities between men and women, with patients in their 40,50s accounting for 49% of patients and 56% of implant treatments; the largest share of patients and implant treatments. 2. Mn. posterior area accounted for 59% of implant treatments followed by Mx. posterior area(21%), Mx anterior area(l4%) and Mn anterior area 2%. 3. Partial edentulous patients treated by single crown and bridge-type prosthesis accounted for 98% and fully edentulous patient accounted for the remaining 2% 4. The major cause of tooth loss is periodontal disease, followed by dental caries, trauma and congenital missing. Compared to women, men are more likely to suffer from tooth loss due to periodontal disease. Also, older people are more likely to suffer from tooth loss due to periodontal disease rather than dental caries. 5. The distribution of bone quality for maxillae was 52% for type III, followed by 23% for type II, 20% for type IV and 0% for type I. As for mandible, the distribution was 52% for type II, followed by 37% for type III, 7% for type IV and 4% for type I. 6. The distribution of bone quantity for maxillae was 49% for type C, followed by 34% for type B, 14% for type D, 3% for type A, and 0% for type E. As for mandible, the distribution was 52% for type B, followed by 35% for type C, 6% for type D, 3% for type A and 0% for type E. 7. The majority of implants were those of 10-14mm in length (80%) and regular diameter in width (79%). The results provided us with basic data on patient type, implant distribution, bone condition, etc. We wish that our results coupled with other research data helps assist in the further study for better implant success/survival rates, etc.

• 한국초전도ㆍ저온공학회논문지
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• 제17권2호
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• pp.25-30
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• 2015

In order to realize economical applications, it is important to reduce the ac loss of 2G high-temperature superconductor coated conductors. It seems to be reasonable that a multi-filamentary wire can decrease the magnetization loss. In this study, we prepared two samples of YBCO coated conductors with striations. We measured local superconducting properties of both samples by using Low Temperature Scanning Laser and Hall Probe Microscopy (LTSLHPM). The distribution of the local critical temperature of samples was analyzed from experimental results of Low Temperature Scanning Laser Microscopy (LTSLM) near the superconducting transition temperature. According to LTSLM results, spatial distributions of the local critical temperature of both samples are homogeneous. The local current density and the local magnetization in samples were explored from measuring stray fields by using Scanning Hall Probe Microscopy (SHPM). From SHPM results, the remanent field pattern of the one bridge sample in an external magnetic field confirms the Bean's critical state model and the three bridge sample has similar remanent field pattern of the one bridge sample. The local magnetization curve in the three bridge sample was measured from external fields from -500 Oe to 500 Oe. We visualized that the distribution of local hysteresis loss are related in the distribution of the remanent field of the three bridge sample. Although the field dependence of the critical current density must be taken into account, the relation of the local hysteresis loss and the remanent field from Bean's model was useful.

• 천문학회보
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• 제38권2호
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• pp.79.2-79.2
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• 2013

The distributions of Horizontal Branch (HB) star color, temperature, and mass encode a great deal of information on the stellar evolutionary and (possibly) dynamical processes taking place in Globular Clusters (GCs). An accurate physical modeling of the Red Giant Branch (RGB) mass-loss process is key to solving the so-called second parameter problem. In my poster I will present the most recent advancements of an analytical model for mass-loss along the RGB. The model predicts the HB mass distribution with remarkable accuracy over a sample of 4 GCs. These results were submitted as a paper to ApJ (Pasquato et al. 2013, ApJ submitted), but here I expand on them presenting refinements to the model and a comparison with HB masses obtained from Galex ultraviolet observations.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.350-353
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• 2000

This paper presents an algorithm for Optimal Reactive Power Dispatch(ORPD) problem based on genetic algorithm. Optimal reactive power dispatch is particularized to the minimization of transmission line losses by suitable selection of generator reactive power outputs and transformer tap settings. To reduce system loss and improve voltage profile, two methods, Loss Re-Distribution Algorithm (LRDA) and Voltage Dependent Load Model (VDLM), are applied to ORPD. The proposed methods have been evaluated on the IEEE 30 bus system. Each of results have been compared with result of load flow.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.363-365
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• 2003

Recently, the concern of power qualiaty problem is increasing. Especially, Voltage quality problem have been increased important problem. Electronic device was affected by voltage sag. So, sensitive load that included many electronic Device was affected by voltage sag. also, it may have economic loss. In this paper, we argue the coordination scheme considering the loss of sensitive load. The coordination device of distribution system for instaneous fault is recloser and sectionalizer, But, the fault clearing time of recloser is more than 2 seconds. So, voltage sag generates long time that affected sensitive load. HS(high speed switchgear) has fast fault clearing time(0.015s) that not affected sensitive load. Therefore, the coordination applied HS is used. The proposed schemes are proved and evaluated by a case study using PSCAD/EMTDC simulation.

• 산업경영시스템학회지
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• 제25권2호
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• pp.1-10
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• 2002

Process capability indices are widely used in industries and quality assurance system. In past years, process capability analysis have been used to characterize process performance on the basis of univariate quality characteristics. However, in actual manufacturing industrial, statistical process control (SPC) often entails characterizing or assessing processes or products based on more than one engineering specification or quality characteristic. Therefore, the analysis have to be required a multivariate statistical technique. This paper introduces to multivariate capability indices and then selects a multivariate process capability index incorporated both the process variation and the process deviation from target among these indices under the multivariate normal distribution. We propose a new multivariate capability index $MC_{pm}^+$ using quality loss function instead of the process variation and this index is compared with the proposed indices when quality characteristics are independent and dependent of each other.

• 산업경영시스템학회지
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• 제30권4호
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• pp.103-110
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• 2007

The facility location in designing a supply chain network is an important decision problem that gives form, structure, and shape to the entire supply chain system. Location problems involve determining the location, number, and size of the facilities to be used. The optimization of these location decisions requires careful attention to the inherent trade-offs among service time, inventory costs, facility cost, transportation costs. This paper presents a strategy that provides the best locations of distribution centers using GIS(Geographical Information System) assuming the limitation of delivery time. To get the best strategy of the location of distribution centers, we use the new loss functions as a penalty when the delivery time is violated

• Journal of Electrical Engineering and Technology
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• 제9권4호
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• pp.1290-1295
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• 2014

In this paper, various configurations of octagonal wound transformer core topology, which has previously proved advantages on conventional wound cores, are studied. Each configuration has different joint types and different placement of joint zones on the core. Magnetic flux distributions and power losses of each configuration are analyzed and compared. Comparisons are based on both 2D&3D finite element simulations and experimental studies. The results show that, joint types and their placements on the core cause local flux accumulations and dramatically affect power loss of the core.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.987-989
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• 2005

Axi-periodic analysis using magnetic vector potential is formulated in time harmonic field and applied to the field analysis for the end region of large turbo generator in this paper. By using axi-periodic analysis, the effect of flux shield, one of the structure placed in the end region of large turbo generator to prevent stator end from thermal damage, is studied, and eddy current loss in the flux shield is estimated for operation conditions. 3D FEA is used for the verification of presented analysis method. Because 3D flux distribution can be calculated with 2D modeling, magnetic field showing 3D distribution can be effectively calculated by axi-periodic analysis comparing with 3D FEA.