• Title/Summary/Keyword: Positive and negative sequence

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A Study on the Relationship between Women's Values and Preference in Clothing Design (한국여성의 가치관과 의복디자인 선호도와의 상관성 연구)

  • Lee Sun Jae
    • Journal of the Korean Society of Clothing and Textiles
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    • v.11 no.1
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    • pp.29-42
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    • 1987
  • This study was an attempt to survey, the relationships between women's values and preference in clothing design. For the measurement of values scale was to relect the theoretical, economic aesthetic, social. political and religious values explained by Allport-vernon- Lindzey. The preference rate in clothing design consisted of 50 items and 3 factors including color, form and texture. The questionnaire were administered to a sample of women (between college students and adult) who lined in Seoul, Korea. The date for 910 respondents were analyzed by person's carrelation coefficient, to-test and $x^2$ test. Through this study, the followings were founds; 1. Aesthetic value was the mast important of female college students values and economic value was the most important of adult's values. 2. There were significant relation between values and the preference for clothing form in line and style; 1) In line preference, adult women indicated negative correlation with religious values but positive correlation with aesthetic and political values. 2) In style preference, adult women indicated negative correlation with economic values positive correlation with social values, for female college students indicated positive correlation with aesthetic social and political values. 3. There were significant relation between values and preference for texture in touch, thickness, weight, light and luster; 1) In relationship between texture and values, adult women indicated touchness preference negative correlation with theoretical and religious values, for female college students indicated positive correlation with aesthetic and social values. 2) In thickness preference adult women indicated negative correlation with theoretical values but female college students indicated positive correlation with political values. 3) In weight preference, adult women indicated negative correlation with theoretical values. But female college students indicated positive correlation with religious values. 4) In brightness preference, only adult women indicated positive correlation with social values, negative correlation with economic values. In transparency preference, adult women indicated positive correlation with aesthetic values, negative correlation with religious values. 4. There were significant correlation among color and economic, aesthetic; political and religious values, that is, evacuation and economic political values in adult women there were positive correlation with religious values in female students. 1) In chroma only adult women indicated negative correlation with religious values. In warm and cold, positive correlation with economic values in both of them. 2) In coloration, adult women like a complement color indicated negative correlation with aesthetic values, but positive correlation with political values. 5. There were significant differences in the preference of clothing design between female college students and adult women; correlationship with color variables. Evacuation, both of them indicated negative correlation with chroma positive correlation with warm and cold and coloration. In chroma, adult women indicated negative correlation with coloration and warm and cold, for female students indicated negative correlation with coloration. 6. Comparison with clothing preference: 1) In color preference, adult women liked the most white, brown, blue and black in sequence. Female college students liked the most white, also the next is blue and pink. 2) Clothing design preference, there was significant difference in warm and cold and coloration, adult women more liked than female students. In shape of clothing, both of them indicated significant difference in line and style, female students more liked sporty style. In texture, adult women more liked soft thin light weight and bright. 3) In silhouette preference, the most is H-line, female college students more liked.

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Design of T-N2SCD Detection Model based on Time Window (타임 윈도우 기반의 T-N2SCD 탐지 모델 구현)

  • Shin, Mi-Yea;Won, Il-Young;Lee, Sang-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.11
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    • pp.2341-2348
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    • 2009
  • An intrusion detection technique based on host consider system call sequence or system call arguments. These two ways are suitable when system call sequence or order and length of system call arguments are out of order. However, there are two disadvantages which a false positive rate and a false negative rate are high. In this paper we propose the T-N2SCD detection model based on Time Window in order to reduce false positive rate and false negative rate. Data for using this experiment is provided from DARPA. As experimental results, the proposed model showed that the false positive rate and the false negative rate are lowest at an interval of 1000ms than at different intervals.

Control Strategy for Three-Phase Grid-Connected Converters under Unbalanced and Distorted Grid Voltages Using Composite Observers

  • Nguyen, Thanh Hai;Lee, Dong-Choon
    • Journal of Power Electronics
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    • v.13 no.3
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    • pp.469-478
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    • 2013
  • This paper proposes a novel scheme for the current controller for the grid-side converter (GSC) of permanent-magnet synchronous generator (PMSG) wind turbines to eliminate the high-order harmonics in the grid currents under grid voltage disturbances. The voltage unbalance and harmonics in three-phase systems cause grid current distortions. In order to mitigate the input current distortions, multi-loop current controllers are applied, where the positive-sequence component is regulated by proportional-integral (PI) controllers, and the negative-sequence and high-order harmonic components are regulated by proportional-resonance (PR) controllers. For extracting the positive/negative-sequence and harmonic components of the grid voltages and currents without a phase delay or magnitude reduction, composite observers are applied, which give faster and more precise estimation results. In addition, an active damping method using PR controllers to damp the grid current component of the resonant frequency is employed to improve the operating stability of VSCs with inductor-capacitor-inductor (LCL) filters. The validity of the proposed method is verified by simulation and experimental results.

The Reasonable Concrete-Placing Methods and Sequences of Composite Steel Bridge (강합성형 교량의 합리적인 타설방법과 순서에 관한 연구)

  • Jo, Byung-Wan;Seo, Sug-Gu
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.3 no.2
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    • pp.205-212
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    • 1999
  • Recently, unexpected cracks in the concrete deck slab of composite steel bridges have been widely reported at an early age of concrete placing due to the concrete placing sequence and methods. Accordingly, the analytical research was carried out to verify the negative moment at an internal supports due to the several concrete pouring sequence and to determine the reasonable concrete placing method on the deck slab of composite steel bridge. The results show that the conventional concrete-placing method, which pours concrete first on the positive moment regions and then negative regions, leads to the minimum moment at an internal supports. However, the conventional method produces two impractical construction joints on every spans and makes field engineer to pour concrete continuously. In conclusion, this concrete-placing method was verified to be reasonable only when the construction joint was placed at the $\frac{5}{8}l{\sim}\frac{6}{8}l$ location of the middle span.

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Analysis of Sequence Impedances of 345kV Cable Transmission Systems (실계통 345kV 지중송전선 대칭좌표 임피던스의 해석)

  • Choi, Jong-Kee;Ahn, Yong-Ho;Yoon, Yong-Beum;Oh, Sei-Ill;Kwa, Yang-Ho;Lee, Myoung-Hee
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.7
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    • pp.905-912
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    • 2013
  • Power system fault analysis is commonly based on well-known symmetrical component method, which describes power system elements by positive, negative and zero sequence impedance. In case of balanced fault, such as three phase short circuit, transmission line can be represented by positive sequence impedance only. The majority of fault in transmission lines, however, is unbalanced fault, such as line-to-ground faults, so that both positive and zero sequence impedance is required for fault analysis. When unbalanced fault occurs, zero sequence current flows through earth and skywires in overhead transmission systems and through cable sheaths and earth in cable transmission systems. Since zero sequence current distribution between cable sheath and earth is dependent on both sheath bondings and grounding configurations, care must be taken to calculate zero sequence impedance of underground cable transmission lines. In this paper, conventional and EMTP-based sequence impedance calculation methods were described and applied to 345kV cable transmission systems (4 circuit, OF 2000mm2). Calculation results showed that detailed circuit analysis is desirable to avoid possible errors of sequence impedance calculation resulted from various configuration of cable sheath bonding and grounding in underground cable transmission systems.

Implementation of Dual Current Controller and Realtime Power Limiting Algorithm in Grid-connected Inverter during Unbalanced Voltage Conditions (전원 전압 불평형시 계통연계형 인버터의 유효전력 리플 억제를 위한 듀얼 전류제어기 구현과 출력 전력의 실시간 제한 알고리즘)

  • Song Seung-Ho;Kim Jeong-Jae
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.55 no.1
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    • pp.54-60
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    • 2006
  • A power limiting algorithm is proposed for stable operation of grid-connected inverter in case of grid voltage unbalance considering the operation limit of inverter. During the voltage unbalance the control performance of Inverter. is degraded and the output power contains 120Hz ripple due to the negative sequence of voltage. In this paper, conventional dual sequence current controller is implemented to solve these problems using separated control of positive and negative sequence. Especially the maximum power limit which guarantees the maximum rated current of the inverter is automatically calculated as the instant grid voltage changes. As soon as the voltage recovers the proposed algorithm can return to the normal power control mode accomplishing low voltage ride through. Proposed algorithm is verifed using PSCAD/EMTDC simulations and tested experimentally at 4.4kW wind turbine simulator set-up.

Grid-connected Inverter Control Algorithm for Torque Ripple Compensation in Doubly-Fed Induction-type Wind Power Generation System (전원 전압 불평형시 이중여자 유도형 풍력발전 시스템의 토크 리플 저감을 위한 계통연계 인버터 제어 알고리즘)

  • Jeong, Byoung-Chang;Song, Seung-Ho
    • Proceedings of the KIEE Conference
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    • 2005.10c
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    • pp.317-319
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    • 2005
  • In this paper, control algorithm for torque ripple compensation in DFIG wind power generation system is proposed. A simple PI controller is designed for the negative sequence voltage cancellation using negative sequence currents in the grid-side converter. As a result, the stator voltage contains only the positive sequence components and the torque pulsation of the generator is effectively compensated. Propose algorithm is confirmed with PSCAD simulation model.

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The Effect of Automated Observation and Vibration Feedback System for Preventing VDT Syndrome of Office Workers (사무직 근로자들의 VDT 증후군 예방을 위한 자동 관찰 및 진동 피드백 시스템의 효과성 검증)

  • Ahn, Ji Yeon;Oah, Shezeen
    • Journal of the Korean Society of Safety
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    • v.34 no.3
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    • pp.75-82
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    • 2019
  • The purpose of this study was to evaluate the effectiveness of a vibration feedback system in improving two safe seating postures of office workers. In addition, the relative effectiveness of positive and negative feedback procedures was examined. Participants were four office workers. The dependent variables were the percentages of time participants spent in the safe sitting postures including shoulder, back, and overall body positions during the experimental sessions. A multiple-baseline design counterbalanced across participants was adopted. For two participants, the negative procedure was introduced first after baseline and positive procedure was introduced in the next phase. For the other two participants, the sequence of introducing the positive and negative feedback procedures was reversed. The result showed that the vibration feedback system, regardless of the type of the procedure, was effective in improving the safe sitting postures for all participants. However, the difference between the two procedures was not clearly shown. The benefits of the automated observation and vibration feedback system in workers' safety were discussed.

Genetic Algorithm based B-spline Fitting for Contour Extraction from a Sequence of Images (연속 영상에서의 경계추출을 위한 유전자 알고리즘 기반의 B-spline 적합)

  • Heo Hoon;Lee JeongHeon;Chae OkSam
    • Journal of KIISE:Software and Applications
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    • v.32 no.5
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    • pp.357-365
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    • 2005
  • We present a B-spline fitting method based on genetic algorithm for the extraction of object contours from the complex image sequence, where objects with similar shape and intensity are adjacent each other. The proposed algorithm solves common malfitting problem of the existing B-spline fitting methods including snakes. Classical snake algorithms have not been successful in such an image sequence due to the difficulty in initialization and existence of multiple extrema. We propose a B-spline fitting method using a genetic algorithm with a new initial population generation and fitting function, that are designed to take advantage of the contour of the previous slice. The test results show that the proposed method extracts contour of individual object successfully from the complex image sequence. We validate the algorithm by false-positive/negative errors and relative amounts of agreements.

ON CONDITIONALLY DEFINED FIBONACCI AND LUCAS SEQUENCES AND PERIODICITY

  • Irby, Skylyn;Spiroff, Sandra
    • Bulletin of the Korean Mathematical Society
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    • v.57 no.4
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    • pp.1033-1048
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    • 2020
  • We synthesize the recent work done on conditionally defined Lucas and Fibonacci numbers, tying together various definitions and results generalizing the linear recurrence relation. Allowing for any initial conditions, we determine the generating function and a Binet-like formula for the general sequence, in both the positive and negative directions, as well as relations among various sequence pairs. We also determine conditions for periodicity of these sequences and graph some recurrent figures in Python.