• Title/Summary/Keyword: Comparison Analysis

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Electron-Morphometric Classification of the Native Honeybees from Korea. Part III. Discriminant Analysis for Different Localities Based on the Total Characters (한국산 재래꿀벌의 전자계량형태학적 분류. III. 전 47형질에 대한 각 지역간 판정분석)

  • 권용정;허은엽
    • Korean journal of applied entomology
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    • v.32 no.1
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    • pp.42-50
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    • 1993
  • Some multivariate discriminant analyses were done for each population of the native honeybee workers (Apis cerana), which were selected for 11 different localities in spring and 12 in summer from Korea. When the comparison for different localities was conducted, the correct assignment was averaged at 91.67% in spring and 88.44% in summer. And for the comparison between the 2 different seasons, it was averaged at 97.58%. Whereas, that regardless of seasons revealed the lowest correct assignment at 70.16%.

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Empirical Comparison of Measurement Methods for Educational Service Quality

  • Kang, Sung;Choi, Kyung-Ho
    • Journal of the Korean Data and Information Science Society
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    • v.19 no.3
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    • pp.801-809
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    • 2008
  • Nowadays almost all universities are endeavoring to improve the quality of education offered. The quality of education that is provided should be measured beforehand. This study examined three methods, SERVQUAL, SERVPERF and Lee and Yun(2004)'s method of measuring service quality: SERVQUAL, SERVPERF are well known and the most commonly used measurement of the quality of education offered and the Lee and Yun(2004)'s method measures service quality using fuzzy numbers. As a result of this research, SERVQUAL was proven to be the most efficient method to measure the quality of education offered. Even though, more actual analysis related to this study should be followed, the research is meaningful in a way that it provided clues and reasons for the study.

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A Study on the Prediction and Control of Welding Deformation of the BRACKET TILT in Automotive Parts (I) - Application of FEA- (자동차 부품 BRACKET TILT의 용접변형 예측 미 제어에 관한 연구 (II) -유한요소법의 적용-)

  • 장경복;강성수
    • Journal of Welding and Joining
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    • v.16 no.6
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    • pp.104-112
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    • 1998
  • In the previous study, the countermeasure for welding deformation of bracket tilt is through up through experimental inspection for total process including welding process. For completeness of systematic examination of parts having sensitivity on welding deformation, the comparison and feedback between the result through simulation of welding process and experimental data is needed. In other words, it is necessary to control welding deformation that construct the prediction system for welding deformation through comparison and tuning with experimental data. In the present study, the application of FEA on welding process of bracket tilt with susceptibility to deformation is made and deformation behavior through change of welding sequence is focused on. It is used to improve the exactness of deformation analysis that three dimensional analysis for moving heat source, activated and deactivated bead element, and volume heat flux etc.

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Comparison and Study of Active and Hybrid Power Filters for Compensation of Grid Harmonics

  • Gutierrez, Bryan;Kwak, Sang-Shin
    • Journal of Power Electronics
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    • v.16 no.4
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    • pp.1541-1550
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    • 2016
  • This paper presents a theoretical analysis and comparisons of active power filter (APF) and hybrid power filter (HPF) systems, given terminal constraints of harmonic compensations in nonlinear loads. Despite numerous publications for the two types of filters, the features and differences between them have not been clearly explained. This paper presents a detailed analysis of the operations of a HPF inverter along with those of passive power filters (PPFs). It also includes their effects on the power factor at the grid. In addition, a theoretical analysis and a systematic comparison between the APF and HPF systems are addressed based on system parameters such as the source voltage, output power, reactive component size, and power factor at the grid terminals. The converter kVA ratings and dc-link voltage requirements for both topologies are considered in the presented comparisons

The Analysis of the Characteristics of Aircraft Turbulence using Radiosonde data (Radiosonde 자료를 이용한 항공기 난류 특성 분석)

  • Kim, Young-Chul;Park, Sang-Hwan
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.15 no.4
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    • pp.94-99
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    • 2007
  • The purpose of this study is analysis of aircraft turbulence of mid Korea using VWS from Osan radiosonde data and comparison with the PIREPs reporting the aircraft turbulence during $1990{\sim}1999$. The results of this study summarized that the frequence of aircraft events is more higher in winter time and in lower level(near the surface) of the atmosphere from VWS analysis using radiosonde data. And comparison with PIREPs data shows that relatively high skill score(44%) using the VWS method. It appears that the operational forecast skill score of aircraft turbulence is much higher using VWS than empirical method, due to the upgrade of the discrimination criteria of the aircraft turbulence.

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An Effect of the Complexity in Vehicle Dynamic Models on the Analysis of Vehicle Dynamic Behaviors: Model Comparison and Validation (차량 모델의 복잡성이 차량동력학 해석에 미치는 영향 : 모델의 비교 및 검증)

  • 배상우;윤중락;이장무;탁태오
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.6
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    • pp.267-278
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    • 2000
  • Vehicle dynamic models in handing and stability analysis are divided into three groups: bicycle model, roll axis model and full vehicle model. Bicycle model is a simple linear model, which hag two wheels with load transfer being ignored. Roll axis model treats left and right wheels independently. In this model, load transfer has a great effect on nonlinearity of tire model. Effects of suspension system can be analyzed by using full vehicle model, which is included suspension stroke motions. In this paper, these models are validated and compared through comparison with road test, and the effects of suspension kinematics and compliance characteristics on vehicle motion are analyzed. In handling and stability analysis, roll axis model can simulate the real vehicle motion more accurately than full vehicle model. Compliance steer has a significant effect, but the effect of suspension kinematics is negligible.

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Qualitative Analysis by Derivative Spectrophotometry (II) - Computer-assisted spectral analysis using derivative spectra and Root Mean of Squares of differences -

  • Park, Man-Ki;Park, Jeong-Hill;Cho, Jung-Hwan
    • Archives of Pharmacal Research
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    • v.12 no.4
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    • pp.289-294
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    • 1989
  • A computer program which can differentiate compounds whose absorbance spectra are very similar was developed. The program. [SPECMAN PLUS], written in Pascal provides automated spectral comparison techniques, utilizing the values of Root Mean of Squares (RMS) of differences. This comparison routine of the program can deal with spectra of compounds different concentrations and different spectral recording resolutions. In addition, the program was designed applicable to any spectral data of digital form. The program was applied to the UV spectra of 13 pencillins and 5 cephalosporins, whose absorbance spectra are so similar. As a result, all compounds examined could be differentiated from each other.

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Characteristics Analysis of Short Flux Path Switched Reluctance Motor

  • Ahn, Jin-Woo
    • Journal of international Conference on Electrical Machines and Systems
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    • v.1 no.2
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    • pp.38-45
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    • 2012
  • A novel kind of switched reluctance motor (SRM) with short flux path is proposed in this paper. Phase excitation in the SRM gives short flux paths, hence reducing the magnetomotive force required to drive the machine, resulting in significant reduction of copper wire and core losses compared to the typical SRM with diametric circulation of magnetic flux. To verify the performance, the characteristics analysis of a double-stator SRM, a 6/5 SRM with C-core structure, and a 4/5 two-phase SRM, which all have short flux paths, and a comparison with conventional SR motors are executed. The comparison demonstrates that the proposed motor offers some advantages in terms of torque and efficiency.

Nonlinear analysis of interaction between flexible pile group and soil

  • Liu, Jie;Li, Q.S.;Wu, Zhe
    • Structural Engineering and Mechanics
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    • v.20 no.5
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    • pp.575-587
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    • 2005
  • Using the nonlinear load transfer function for pile side soil and the linear load transfer function for pile end soil, a combined approach of the incremental load transfer matrix method and the approximate differential equation solution method is presented for the nonlinear analysis of interaction between flexible pile group and soil. The proposed method provides an effective approach for the solution of the nonlinear interaction between flexible pile group under rigid platform and surrounding soil. To verify the accuracy of the proposed method, a static load test for a nine-pile group under a rigid platform is carried out. The finite element analysis is also conducted for comparison purposes. It is found that the results from the proposed method match very well with those from the experimental test and are better in comparison with the finite element method.

Performance Analysis of Moving Bed Heat Exchanger of Solid Particles in a Vertical Pipe (고체입자 이동층을 이용한 수직 전열관 열교환기의 성능해석)

  • Park, Sang-Il;Choe, Gyeong-Bin
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.9
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    • pp.2916-2923
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    • 1996
  • A numerical analysis of the moving bed heat exchanger of solid particles inside the vertical pipe was performed using finite difference method. Also, the theoretical solutions were obtained for comparison when the wall heat flux or the wall temperature was assumed constant. The comparison showed that their results agreed well each other. The moving bed heat exchanger was classified as countercurrent-flow, parallel-flow, and cross-flow types according to the gas flow direction. For each type, the thermal efficiency of heat exchanger was calculated as a function of non-dimensional parameters such as the characteristic length of heat exchanger, Biot number and the ratio of thermal capacities of gas and solid particles.