• Title/Summary/Keyword: Relative Degree

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A Study on the Dynamic Reduction of Large-Scale Power Systems (대규모 계통의 동적 축약에 관한 연구)

  • Kim, Hyung-Jun;Jang, Gil-Soo;Yoon, Yong-Beum;Lee, Jin
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.49 no.8
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    • pp.399-404
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    • 2000
  • This paper presents new algorithms equivalencing large-scale power systems. Generators are identified to the coherent groups according to the relation factors, which represent the relative coupling degree between the generators. While the groups are identified, participation numbers, which are the measure of the relative participation of the generators in the group, are obtained. All generators and controllers in the group are weighted by participation numbers and aggregated to construct a dynamic equivalent. The proposed algorithms are applied to a 272-machine Korea Electric Power Corporation (KEPCO)'s system. The enclosed results indicate the accuracy and usefulness of the algorithms.

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Individual differences in autistic traits and variability in production patterns: a case of affricates by young Seoul Korean speakers

  • Kang, Soyoung;Kong, Eun Jong;Seo, Misun
    • Phonetics and Speech Sciences
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    • v.7 no.1
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    • pp.125-131
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    • 2015
  • The current study explores whether speaker variability in the fronted articulations of Seoul Korean affricates can be explained by cognitive differences measured by individual autistic traits. The goal was to explore Yu's (2010; 2013) proposal that individual differences in cognitive style can be an important factor in speakers' use of sound variants. The spectral peak frequencies (SPF) of affricates relative to those of fricatives, reported in Kong et al. (2014), were used to acoustically represent the relative degree of anterior place of constriction. When these individual SPFs were related to the scores of Autistic-Spectrum Quotients (Baron-Cohen et al., 2001), a correlation was found for the male speakers, but not for the female speakers, such that speakers of more anterior affricate productions scored low in AQs. Discussion is made with respect to how these findings are in line with Yu's proposal.

An absolute displacement approach for modeling of sliding structures

  • Krishnamoorthy, A.
    • Structural Engineering and Mechanics
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    • v.29 no.6
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    • pp.659-671
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    • 2008
  • A procedure to analyse the space frame structure fixed at base as well as resting on sliding bearing using total or absolute displacement in dynamic equation is developed. In the present method, the effect of ground acceleration is not considered as equivalent force. Instead, the ground acceleration is considered as a known value in the acceleration vector at degree of freedom corresponding to base of the structure when the structure is in non-sliding phase. When the structure is in sliding phase, only a force equal to the maximum frictional resistance is applied at base. Also, in this method, the stiffness matrix, mass matrix and the damping matrix will not change when the structure enters from one phase to another. The results obtained from the present method using absolute displacement approach are compared with the results obtained from the analysis of structure using relative displacement approach. The applicability of the analysis is also demonstrated to obtain the response of the structure resting on sliding bearing with restoring force device.

A Study on Effects of Antenna Diversity in Doppler Spread Environments (도플러 확산 환경에서의 안테나 다이버시티 효과에 관한 연구)

  • Lee Jong-Gil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.3
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    • pp.510-515
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    • 2005
  • Doppler spread can occur due to the relative movement of transmitter and receiver. The Doppler frequency shift varies as the relative location and the velocity of transceivers change. This Doppler spread may seriously degrade the performance of OFDM system which is considered to be very efficient for multimedia wireless communication. Therefore, applying the method of receiver diversity, we analyze the degree of BER improvement in Doppler spread environments to investigate the effectiveness of the chosen methods according to various wireless channels.

Analysis of Precision According to Photographing Position in Close-Range Digital Photogrammetry (근접수치사진측량의 촬영위치에 따른 정밀도 해석)

  • Seo, Dong-Ju;Lee, Jong-Chool
    • Journal of Korean Society for Geospatial Information Science
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    • v.11 no.3 s.26
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    • pp.3-11
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    • 2003
  • This study has made photographing respectively by changing the photographic distance, converging angle, picturing direction by use of Rollei d7 metric and d7 $metric^{5}$ that is a measurement digital camera. And also in order to minimize the errors happened at the relative orientation, we have sorted out the round target that the relative orientation is automatically on the programming and have calculated RMSE by carrying out the bundle adjustment. We think that such a study could be used as very important basic data necessary in deriving the optimal photographic conditions by the close-range digital photogrammetry and in judging such a degree.

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A Study on Life Management Strategy and Variables of Unmarried Men and Women (미혼남녀의 생활관리전략과 관련변인 연구)

  • 이정숙
    • The Korean Journal of Community Living Science
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    • v.14 no.1
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    • pp.37-53
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    • 2003
  • The purpose of this study was to empirically verify influence of objective variables and subjective variables of life management strategy of unmarried man and women and provide a basis for the development of time management. The subject of this study were 355 unmarried men and women and interviewed with a questionnaire. The data were analyzed by SPSS program for the frequency, mean, standard deviation, t-test and regression analysis. The major results of this study were as follows: 1. The score of time management strategy of unmarried man and women was the highest. The score of leisure management strategy of unmarried man and women was the lowest. 2. Variables that affect overall life management strategy were academic career, degree of information using, fate control orientation and perception level of living relative to others. 3. The relative contribution of subjective variables on life management strategy were higher than objective variables.

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Determination of Sampling Unit Size for Cultivation Area Survey using Remote Sensing Technology

  • Park, Jin-Woo;Shin, Gi-Eun;Lee, Suk-Hoon;Byun, Jong-Seok
    • The Korean Journal of Applied Statistics
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    • v.25 no.5
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    • pp.733-741
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    • 2012
  • The successful launch of Arirang satellites allow the acquisition of high resolution satellite imagery of Korean territory and enables the transition from the conventional cultivation area survey method to new image based methods adopted in advanced nations. In this study, we suggested reasonable sizes of the primary sampling unit and the secondary sampling unit for the satellite imagery based sampling design in 8 provinces preselected for this research. The PSU size was determined mainly in consideration of intracorrelation that shows the degree of homogeneity within each cluster and the efficiency of the image process. For the SSU size, we considered the relative standard error and the differences between the land cover maps produced by the Ministry of Environment and the satellite imagery processed by the National Statistical Office.

Development of an Efficient Vehicle Dynamics Model Using Massless Link of a Suspension (현가장치 무질량 링크를 이용한 효율적인 차량동역학 모델 개발)

  • Jung Hongkyu;Kim Sangsup
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.1
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    • pp.99-108
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    • 2005
  • This paper represents an efficient modeling method of a suspension system for the vehicle dynamic simulation. The suspension links are modeled as composite joints. The motion of wheel is defined as relative one degree of freedom motion with respect to car body. The unique relative kinematic constraint formulation between the car body and wheel enables to derive equations of motion in terms of wheel vertical motion. Thus, vehicle model has ten degrees of freedom. By using velocity transformation method, the equations of motion of the vehicle is systematically derived without kinematic constraints. Various vehicle simulation such as J-turn, slowly increasing steer, sinusoidal sweep steer and bump run has been performed to verify the validity of the suggested vehicle model.

The Propensity for Conspicuous Consumption of Adolescent Consumer and Its Related Factors (청소년 소비자의 과시소비 성향과 관련요인 -인천광역시를 중심으로-)

  • 이은희
    • Journal of Families and Better Life
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    • v.17 no.1
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    • pp.15-32
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    • 1999
  • The objectives of this study are to examine the propensity of conspicuous consumption of adolescent consumers to investigate the effects of demographic variables socio-psychologival variables materialism on the conspicuous consumption of adolescent consumers. The survey of this research was conducted by means of self-administered questionnaire with 483 adolescent consumers attending middle school located in Inchon. Major findings are the following: (1) The propensity for conspicuous consumption of adolescent consumers averages 47.98 points. This score is beyound the middle slightly. (2) According to the results for examining the relative influences of variables affecting conspicuous consumption of adolescent consumers the relative importance stars school education the degree of taking in advertisement attitude of their parents self-esteem materialism gender and educational level of their father. Explanatory power of these variables totalled 70.5%.

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Computational Study of Proline - Water Cluster

  • Lee, Kyung-Min;Park, Sung-Woo;Jeon, In-Sun;Lee, Bo-Ra;Ahn, Doo-Sik;Lee, Sung-Yul
    • Bulletin of the Korean Chemical Society
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    • v.26 no.6
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    • pp.909-912
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    • 2005
  • Calculations are presented for the structures of various conformers of the bare proline and proline –($H_2O$) cluster. The effects of hydrogen bonding with a water molecule on the relative stability of the low energy conformers of proline are examined. Microsolvation by a water molecule is predicted to affect the relative stability, structures and the infrared frequencies of the conformers to a large degree.