• Title/Summary/Keyword: principal point

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Probabilistic Security Analysis in Composite Power System Reliability (복합전력계통 신뢰도평가에 있어서 확률론적 안전도연구)

  • Kim, H.;Cha, J.;Kim, J.O.;Kwon, S.
    • Proceedings of the KIEE Conference
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    • 2005.11b
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    • pp.46-48
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    • 2005
  • This paper discusses a probabilistic method for power system security assessment. The security analysis relates to the ability of the electric power systems to survive sudden disturbances such as electric short circuits or unanticipated loss of system elements. It consists of both steady state and dynamic security analyses, which are not two separate issues but should be considered together. In steady state security analysis including voltage security analysis, the analysis checks that the system is operated within security limits by OPF (optimal power flow) after the transition to a new operating point. Until now, many utilities have difficulty in including dynamic aspects due to computational capabilities. On the other hand. dynamic security analysis is required to ensure that the transition may lead to an acceptable operating condition. Transient stability, which is the ability of power systems to maintain synchronism when subjected to a large disturbance. is a principal component in dynamic security analysis. Usually any loss of synchronism may cause additional outages and make the present steady state analysis of the post-contingency condition inadequate for unstable cases. This is the reason for the need of dynamic studies in power systems. Probabilistic criterion can be used to recognize the probabilistic nature of system components while considering system security. In this approach. we do not have to assign any predetermined margin of safety. A comprehensive conceptual framework for probabilistic static and dynamic assessment is presented in this paper. The simulation results of the Western System Coordinating Council (WSCC) system compare an analytical method with Monte-Carlo simulation (MCS).

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A Study on the Effect of Trim on the Resistance in a Small Coastwise Passenger Boat (소형연안객선(小型沿岸客船)의 Trim변화(變化)가 저항(抵抗)에 미치는 영향(影響))

  • J.H.,Hwang;K.J.,Bai
    • Bulletin of the Society of Naval Architects of Korea
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    • v.4 no.1
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    • pp.49-54
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    • 1967
  • The authors considered the effects of trim in the small coastal passenger boat upon resistance in this paper. Any change of trim no matter how small, necessarily produces some effect upon resistance. The relations between the resistance coefficients and trim were investigated through the towing test of the Model $MCI-P_1-65$, Korean Standardized Ship, GT 70 tons passenger boat in the gravitational tank. The Lines of the Model are given in Fig. 1. Principal dimensions and other characteristics vary with the trim in general. Those values varied with the trim for $MCI-P_1-65$ are tabulated in table 1. The resistance was measured at five conditions such as even keel, 0.0273L, (original designed trim) 0.0473L, 0.0663L, 0.0873L trim by the stern, fixing the displacement corresponding to the designed load water line. Model was made of wood in length of 3.5 feet coated with varnish, and without appendages. As the artificial turbulent stimulator, the sand strip method was used. The results of model towing tests, correcting to water temperature of $70^{\circ}F$, were expanded to full scale using the Schoenherr's friction formula and surface roughness allowance coefficient of 0.0004. The authors point out, the following results. 1) Optimum trim which gives the minimum resistance exists for every speed at constant displacement and each comes to the same value. For $MCI-P_1-65$ optimum trim is 0.0673L trim by the stern(Fig.4-The cross curves of the resistancecoefficients). 2) At constant displacement, when LCB(longitudinal position of center of buoyancy) varies with the trim, there exists optimum value of LCB which gives minimum resistance for every speed and each comes to the same value. For $MCI-P_1-65$ optimum position of LCB is 8%L aft from midship section (Fig.6).

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Electromagnetic Field Exposure and Male Breast Cancer Risk: A Meta-analysis of 18 Studies

  • Sun, Jing-Wen;Li, Xiao-Rong;Gao, Hong-Yu;Yin, Jie-Yun;Qin, Qin;Nie, Shao-Fa;Wei, Sheng
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.1
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    • pp.523-528
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    • 2013
  • Background: The possibility that electromagnetic fields (EMF) exposure may increase male breast cancer risk has been discussed for a long time. However, arguments have been presented that studies limited by poor quality could have led to statistically significant results by chance or bias. Moreover, data fo the last 10 years have not been systematically summarized. Methods and Results: To confirm any possible association, a meta-analysis was performed by a systematic search strategy. Totals of 7 case-control and 11 cohort studies was identified and pooled ORs with 95% CIs were used as the principal outcome measures. Data from these studies were extracted with a standard meta-analysis procedure and grouped in relation to study design, cut-off point, exposure assessment method, adjustment and exposure model. A statistical significant increased risk of male breast cancer with EMF exposure was defined (pooled ORs = 1.32, 95% CI = 1.14-1.52, P < 0.001), and subgroup analyses also showed similar results. Conclusions: This meta-analysis suggests that EMF exposure may be associated with the increase risk of male breast cancer despite the arguments raised.

A Q-Methodological Study on the Radiologist's Image of Radiology College Students Experienced Clinical Practice (임상실습을 경험한 방사선과 학생의 방사선사 이미지에 대한 주관성 연구)

  • Kim, Young-Ran
    • Journal of the Korea Convergence Society
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    • v.11 no.7
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    • pp.51-57
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    • 2020
  • This study was conducted to examine the type of subjective perceptions and characteristics of the type toward the image of students enrolled in the Department of Radiology who experienced clinical training by applying Q Methodology which is aiming at the research of human subjectivity, and provide basic data for educational programs for the Department of Radiology to establish the image of a radiological technologist based on the result. This study conducted convenience sampling with 30 students of the Department of Radiology who experienced their first clinical training for 8 weeks as a P sample, forcing 33 Q samples to be distributed on the nine-point scale Q distribution chart. After that, this study processed collected data with principal factor analysis by QUANL program. Study results show that Eigen value was more than 1.0, which was divided into 2 types. Type 1 was "Patient-oriented" and type 2 was "Organization-oriented". These results can be helpful as a basic resources to understand Radiology Students who will choose a job by using different sense of value of their job.

A Study on Make-up Behavior and Cosmetics Purchasing Pattern of Male (남성의 화장행동과 화장품 구매에 관한 연구)

  • Lee, Il-Cheong;Choi, Eun-Me
    • Journal of the Korean Society of Fashion and Beauty
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    • v.2 no.2 s.2
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    • pp.34-47
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    • 2004
  • The objective of this study is to investigate the perception of males about make-up and the make-up process, analyze principal factors affecting their decision when purchasing cosmetics and, ultimately, to provide basic data for further survey and research into features of cosmetics and their satisfaction. The subjects of the study a.e male adults living in Jeonju, Iksan and Gunsan cities of Jeonbuk province. Surveyors made direct interviews with the subjects from October 21 to 30, 2003 and collected 174 questionnaires from them, which were subsequently put to the final analysis. The demographic characters of the surveyed showed that 60.9% of them were in the age ranging 30 to 39, 75.3% married, 69.5% undergraduates or graduates, 39.1% self-employed, 25.9% earning more than 3.01 million Won monthly and 43.7% spending less than 10,000 Won a month for cosmetics. Their make-up and purchasing pattern of cosmetics featured that 54.0% of the surveyed use cosmetics for skin care, 54.0% for cleanness and health, 84.5% for foundation(lotion or skin lotion) only, and 60.9% once a day. Out of the surveyed males, 79.3% haven't experienced any adverse side effects after make-up. Of those who experienced, 80.5% named disagreement of cosmetics with skin for the reason. As for kind or symptom of the side effects, 38.8% set forth itching. Among those who had aftermath or intoxication from make-up, 52.8% said they could recover naturally. According to the survey, 57.5% felt somewhat awkward after make-up, but not quite bad though. Thirty-seven point nine percent of the males surveyed replied they cared little about the purpose of male-oriented cosmetics. Quality was raised by 31.0% as the foremost issue to improve. Television turned out to be the main source for 56.9% of the surveyed to get information about cosmetics. For 56.35%, general discount shops are preferred to buy cosmetics and 24.7% of them take ones recommended by salespeople. When buying cosmetics, 47.1% considered color and fragrance most seriously.

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Estimating Three-Dimensional Scattering Centers of a Target Using the 3D MEMP Method in Radar Target Recognition (레이다 표적 인식에서 3D MEMP 기법을 이용한 표적의 3차원 산란점 예측)

  • Shin, Seung-Yong;Myung, Noh-Hoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.2
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    • pp.130-137
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    • 2008
  • This paper presents high resolution techniques of three-dimensional(3D) scattering center extraction for a radar backscattered signal in radar target recognition. We propose a 3D pairing procedure, a new approach to estimate 3D scattering centers. This pairing procedure is more accurate and robust than the general criterion. 3D MEMP(Matrix Enhancement and Matrix Pencil) with the 3D pairing procedure first creates an autocorrelation matrix from radar backscattered field data samples. A matrix pencil method is then used to extract 3D scattering centers from the principal eigenvectors of the autocorrelation matrix. An autocorrelation matrix is constructed by the MSSP(modified spatial smoothing preprocessing) method. The observation matrix required for estimation of 3D scattering center locations is built using the sparse scanning order conception. In order to demonstrate the performance of the proposed technique, we use backscattered field data generated by ideal point scatterers.

The Meaning of Anthony Browne's Picture Book 'Gorilla' : Mainly about the Semiology of A.J. Greimas (앤서니 브라운 그림책 '고릴라' 의미연구:그레마스 기호학을 중심으로)

  • Kim, Young-Su
    • The Journal of the Korea Contents Association
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    • v.10 no.2
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    • pp.176-183
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    • 2010
  • Picture book is the artistic format to develop forms an organic relationship with text and illustration. Not only meaning which the text and illustration deliver from the picture book but understand the symbolic meaning can discover new enjoyment of reading picture book. Sees the text and illustration of the picture book at one unit which is put in indivisible relationship and analyzing in semeiology provides the viewpoint which is important in picture book comprehension. The Greimas's theory of signification leads and understands the interaction of the text and illustration of world-famous author Anthony Browne's picture book 'Gorilla'. In addition, analysing the structural connection with text and visual expression it approaches the integrated meaning of a story from a new point of view. From the researches of existing interpreted the Hanna and relationship of dad was simple being lonely but this research sees which there exists not only paternal love but also heterosexuality between Hanna and dad and could newly be interpreted with the viewpoint where heal the discord is principal.

A Qualitative Analysis on Familial Caregivers' Burden in Utilizing a Nursing Home for the Elderly (유료 노인전문요양원 이용 경험에 관한 질적 연구)

  • 김완희;박종연;이지전;강임옥
    • Health Policy and Management
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    • v.13 no.1
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    • pp.1-22
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    • 2003
  • The principal objective of this study was to analyze and conceptualize the socio-psychological burden in utilizing a nursing home for elderly. The subjects were five elderly from a private nursing home located in Seoul and their familial caregivers. An old male and three females were currently staying at the facility, and a female had been discharged already from there. Data were collected through depth interviews, observations and review of records at the facility For analysis, the data were classified by similar contents among significant expressions and factors in common. The subjects' motives to consider admission to the nursing home might be attributed to familial caregivers' burden, a shortage of support, environmental improvement and feeling of helplessness for the case elderly. The concept of burden is including family members' being badly off in living, their weariness, complications among family members, feeling psychological uneasiness, and hospital expenses. The identified image of nursing homes for the elderly in Korea was generally negative at the point of high cost, unreasonable requisites and limitations for admission to the facilities, inferior situations, and especially in that there were few long-term care facilities within the community boundary. From their experience of nursing homes, the interviewees have felt the sentiments of sorry for their old parents, with the thought of being an undutiful, bitterness, and empathy. Additionally, they expressed a sense of anxiety of relative deprivation against the fact that there were no long-term care facilities available for the middle class. On the basis of these, multi-dimensional needs could be identified for the elderly with chronic illnesses.

Study of the Muscle Activity of Small Intestine Channel of Hand Taiyang Muscle Using Contact Reflex Analysis (접촉반사분석법을 이용한 수태양경근의 근육 활성도에 대한 연구)

  • Lee, Kwang Gye;Oh, Jong Hyun;Lee, Sang Ryong
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.6
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    • pp.947-952
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    • 2012
  • This Study was conducted to investigate Muscle Test of Point Selection through CRA(Contact Reflex Analysis) Muscel Diagnosis. So this study used to compare and analyze the effects of Muscel(Deltoid Muscel of Posterior) RMS(Root Mean Squared) and MEF(Median Edge Frequency) Among Groups that do not respond to questionnaire, Tonguibogam Naegyeongpyeon Small Intestine Group, Small Intestine MeridianPathway Primary Symptom and Secondary Symptom Group and Kwanwon(CV4) meridian Principal action Group. The questionnaire is composed of 23 items. The questionnaire was intended to elicit information on assorting into 4 groups. After Survey, Subject had to Muscle test subjects. Muscle experimental methods are as follows: Holding the shoulder without contacting Kwanwon. Holding the shoulder contacting Kwanwon. The first iteration. Group 1,2,3 were increased sEMG RMS compared with First experiment and Second experiment. Group 4(Including Uterus and Intestinal Flora Problem) were decreased sEMG RMS compared with First experiment and Second experiment. This test means that it is similar to diagnosis CRA and Small intestine channel of hand taiyang muscle, not Small Intestine MeridianPathway. It is suggested that subjects with a Small Intestine problem(Uterus and Intestinal Flora Problem) shows the results of decreasing posterior Deltoid Muscular strength. It means that CRA muscle diagnosis is associated with Alarm points diagnosis. But it doesn't consider influence of fat on the surface EMG.

Design Guideline Development for Managed Lane Access Spacing Using Gap Acceptance Theory (간격수락 이론을 이용한 다인승전용차로 진.출입을 위한 도로 디자인 지침정립)

  • Yang, Cheol-Su;Mattingly, Stephen P.;Kim, Hyeon-Ung;Gwon, Yong-Jang
    • Journal of Korean Society of Transportation
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    • v.28 no.4
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    • pp.177-186
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    • 2010
  • The principal objective of this paper is to develop road design guidelines, especially for managed lane access spacing between the expressway on-ramp (or off-ramp) and managed lane access point. Managed lanes are typically located in the expressway median and are accessed by weaving across the mainlines. The high level of lane-changing activity present in weaving areas affects capacity significantly. One promising tool for the analysis of lane-changing activity is "gap acceptance theory." This paper estimates the capacity of weaving areas based on the estimated degree of traffic turbulence using gap acceptance theory. The degree of traffic turbulence is represented by a function of the probability that lane-changing vehicles can complete their maneuvers successfully in a given weaving distance. In developing road design guidelines based on the developed gap acceptance model, the minimum managed lane access spacing is determined where the capacity with respect to the managed lane access spacing becomes stable.