• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 하계학술대회 논문집 A
• /
• pp.716-718
• /
• 2004

This paper presents a formulation and a solution method for the optimization problem with a fuel constraint in a competitive electricity market. Take-or-Pay (TOP) contract for an energy resource is the typical constraint as a limiting factor. Two approaches are proposed in this paper for modeling the dispatch calculation in a market mechanism. The approaches differ in the subject who considers and inserts the fuel-constraint into its optimization problem. Market operator and each power producer having a TOP contract are assumed as such subjects.

• Structural Engineering and Mechanics
• /
• 제52권5호
• /
• pp.1051-1067
• /
• 2014

The structures of concern in this study are subject to two types of forces: dead loads from the acceleration imposed on the structures as well as the installed operation machines and the additional adjustable forces. We wish to determine the critical values of the adjustable forces when buckling of the structures occurs. The mathematical statement of such a problem gives rise to a constrained eigenvalue problem (CEVP) in which the dominant eigenvalue is subject to an equality constraint. A numerical algorithm for solving the CEVP is proposed in which an iterative method is employed to identify an interval embracing the target eigenvalue. The algorithm is applied to four engineering application examples finding the critical loads of a fixed-free beam subject to its own body force, two plane structures and one wide-flange beam using shell elements when acceleration force is present. The accuracy is demonstrated using the first example whose classical solution exists. The significance of the equality constraint in the EVP is shown by comparing the solutions without the constraint on the eigenvalue. Effectiveness and accuracy of the numerical algorithm are presented.

• 한국콘텐츠학회논문지
• /
• 제10권4호
• /
• pp.359-366
• /
• 2010

이 연구의 목적은 민간경비원의 여가제약이 직무스트레스 및 생활만족에 미치는 영향을 규명하는데 있다. 이 연구는 2009년 서울소재 민간경비 회사에 재직하고 있는 민간경비원들을 연구대상으로 판단표집법을 이용하여 최종분석에 사용된 사례 수는 300명이다. 수집된 자료는 SPSSWIN 17.0을 이용하여 요인분석, 신뢰도분석, 회귀분석, 경로분석 등의 방법을 활용하였다. 설문지의 신뢰도는 Cronbach's $\alpha$값이 .600 이상으로 나타났다. 본 연구의 결론은 다음과 같다. 첫째, 민간경비원의 여가제약은 직무스트레스에 영향을 미친다. 즉, 주변 의식적 제약, 개인적 제약이 증가하면 직무스트레스는 높아지는 반면, 대인적 제약이 감소하면 직무스트레스는 낮아진다. 둘째, 민간경비원의 여가제약은 생활만족에 영향을 미친다. 즉, 개인적 제약이 감소하면 생활만족감은 높아진다. 셋째, 민간경비원의 직무스트레스는 생활만족에 영향을 미친다. 즉, 보상 및 경력개발이 증가하면 생활만족감은 높아지는 반면, 직무특성이 감소하면 생활만족감은 낮아진다. 넷째, 민간경비원의 여가제약은 직무스트레스 및 생활만족에 인과적 영향을 미친다. 즉, 직무스트레스는 여가제약과 생활만족의 관계를 매개하는 중요한 변수임을 알 수 있다.

• 한국운동역학회지
• /
• 제26권2호
• /
• pp.175-181
• /
• 2016

Objective: The aim of this study was to investigate age-related changes of multi-finger synergy during a constant force production task with and without an additional mechanical constraint. Method: Fourteen elderly subjects (age: $78.50{\pm}4.63yrs$, height: $157.29{\pm}8.97cm$, weight: $65.13{\pm}6.93kg$) and 14 young subjects (age: $21.13{\pm}1.35yrs$, height: $171.57{\pm}8.43cm$, weight: $70.29{\pm}16.77kg$) participated in this study. The subjects were asked to place their index and middle fingers on two force transducers fixed on a small non-moving teeterboard and produce 10 N by pressing the sensors while watching force feedback on a computer screen under the no additional constraint condition (NAC). The subjects also performed the same task with an additional mechanical constraint (AC) where the subjects were asked to balance a teeterboard that could be rotated by finger forces. An uncontrolled manifold approach was used to calculate within-trial and between-trial multi-finger synergy indices, variance in uncontrolled subspace ($V_{UCM}$), and variance in subspace orthogonal to UCM subspace ($V_{ORT}$). Two-way repeated measured ANOVA was performed with the within-factor of task condition (with and without an additional constraint) and the between factor of groups (elderly and young). Results: The elderly group showed significantly increased within-trial $V_{ORT}$ in AC compared with NAC (p < .05) while the young group showed no significant difference between AC and NAC. There was no significant group difference for within-trial $V_{UCM}$. Between-trial $V_{ORT}$ remained unchanged between groups and conditions. However, between-trial $V_{UCM}$ for the elderly group significantly decreased in AC as compared to NAC, along with no significant difference for the young group. For multi-finger synergy, there was no significant group difference of within-trial synergy. However, between-trial synergy for the elderly group significantly decreased in AC as compared to NAC (p < .05). Conclusion: Our results indicate that aging decreased consistency (i.e., ability to perform the task on a moment-to-moment basis) with an additional mechanical constraint. In addition, aging was associated with decreased multi-finger synergy on a trial-to-trial basis.

• 한국콘텐츠학회논문지
• /
• 제10권7호
• /
• pp.317-325
• /
• 2010

이 연구는 PPA 기법을 적용하여 민간경호경비원들의 여가활동 집중개선 여가활동을 도출하고, 나아가 여가제약이 참가지수에 미치는 영향을 규명하는데 주된 목적이 있다. 이러한 과정을 통하여 최종적으로 민간경호경비원들의 여가후생복지 개선을 위한 정책투자우선순위를 도출하고자 한다. 따라서 본 연구는 2010년 2월 서울 소재 6개소 민간경비업체를 대상으로 판단표집법을 적용하여 최종분석에 사용된 사례 수는 총 267명이다. 수집된 자료는 SPSSWIN 17.0 프로그램으로 요인분석, 신뢰도 분석, 대응표본 t검증, PPA 분석, 회귀분석을 실시하였다. 설문지의 신뢰도는 Cronbach's $\alpha$값이 .768 이상으로 나타났다. 결론은 다음과 같다. 첫째, 민간경호경비원의 여가활동 참가 지수인 선호도와 참여도는 차이가 있다. 중점개선 여가활동은 헬스, 산책/조깅, 숙박관광, 당일여행 등이며, 노력지속 여가활동은 영화, 국내유명관광지, 이성교재, 외식, 대인관계, 스포츠 관람, 독서, 노래방, TV 비디오 시청, 음주 등이다. 개선요망 여가활동은 수상스포츠, 등산, 자전거, 축구, 사진촬영, 구기운동, 항공스포츠, 바둑/장기, 인라인스케이트, 요리 등이다. 둘째, 민간경호경비원의 여가제약은 여가활동 참가지수에 영향을 미친다. 여가제약의 하위요인인 개인내적 제약, 주변의식적 제약이 클수록 선호하는 여가활동 참가지수는 감소하는 반면, 구조적 제약, 시간 경제적 제약과 같은 어려움을 극복할 경우 여가활동 참가지수는 증가한다.

• 말소리와 음성과학
• /
• 제3권3호
• /
• pp.27-33
• /
• 2011

This paper explores two articulatory characteristics of inter-consonantal coordination observed in lingual-lingual (/kt/, /ks/) and labial-lingual (/pt/) sequences. Using electromagnetic articulometry (EMMA), temporal aspects of the lip movement and lingual movement (of the tongue tip and the tongue dorsum) were examined. Three sequences (/ks/, /kt/, /pt/) were investigated in two respects: gestural overlap in C1C2 and formation duration of coronals in C2 (/t/ or /s/). Results are summarized as follows. First, in a sequence of two stop consonants gestural overlap did not vary with order contrast or a low-level motor constraint on lingual articulators. Gestural overlap between two stop consonants was similar in both /kt/ (lingual-lingual; back-to-front) and /pt/ (labial-lingual; front-to-back). Second, gestural overlap was not simply constrained by place of articulation. Two coronals (/s/ and /t/) shared the same articulator, the tongue tip, but they showed a distinctive gestural overlap pattern with respect to /k/ in C1 (/ks/ (less overlap) < /kt/ (more overlap)). Third, temporal duration of the tongue tip gesture varied as a function of manner of articulation of the target segment in C2 (/ks/ (shorter) < /kt/ (longer)) as well as a function of place of articulation of the segmental context in C1 (/pt/ (shorter) < /kt/ (longer)). There are several implications associated with the results from Korean non-assimilating contexts. First, Korean can be better explained in the way of its language-specific gestural pattern; gestural overlap in Korean is not simply attributed to order contrast (front-to-back vs. back-to-front) or a physiological motor constraint on lingual articulators (lingual-lingual vs. nonlingual-lingual). Taking all factors into consideration, inter-gestural coordination is influenced not only by C1 (place of articulation) but also C2 (manner of articulation). Second, the jaw articulator could have been a factor behind a distinctive gestural overlap pattern in different C1C2 sequences (/ks/ (less overlap) vs. /kt/ and /pt/ (more overlap)). A language-specific gestural pattern occurred with reference to a physiological motor constraint on the jaw articulator.

• 한국안전학회지
• /
• 제39권1호
• /
• pp.62-69
• /
• 2024

Ensuring swift on-site access to fire engines is crucial in preserving the golden time and minimizing damage. However, various mobility constraints in alleyways hinder the timely entry of fire engines to the fire scene, significantly impairing their initial response capabilities. Therefore, this study analyzed the significant mobility constraints of fire engines, focusing on Seoul, which has many old town areas. By leveraging survey responses from firefighting experts and actual observations, this study quantitatively assessed the frequency and severity of mobility constraint factors affecting the disaster responses of fire engines. Survey results revealed a consistent set of top five factors regarding the frequency and disturbance level, including illegally parked cars, narrow paths, motorcycles, poles, and awnings/banners. A comparison with actual road-view images showed notable consistency between the survey and observational results regarding the appearance frequency of mobility constraint factors in vulnerable areas in Seoul. Furthermore, the study emphasized the importance of tailored management strategies for each mobility constraint factor, considering its characteristics, such as dynamic or static. The findings of this study can serve as foundational data for creating more detailed fire safety maps and advancing technologies that monitor the mobility of fire engines through efficient vision-based inference using CCTVs in the future.

• 대한전기학회논문지:전력기술부문A
• /
• 제53권9호
• /
• pp.494-499
• /
• 2004

This paper presents to compute the power economic dispatch, an optimal power flow (OPF) computation algorithm, considering the load power factor limits constraint in developed. Efficient reactive power planning enhances economic operation as well as system security. Accordingly, an adequate level of power factor limits for the load busesshould be evaluated for economic operation. In this paper, the ranges of acceptable load power factors are portrayed as bandwidths of load power factor expressed as a function of load level. The load power factor limits are included and described into the OPF's objective function. The method Proposed is applied to IEEE 26 bus system.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
• /
• pp.113-118
• /
• 1986

The feedback controllers for the active vibration control of elastic systems are developed using optimal regulator, optimal tracking, time optimal and noise observer algorithms. Using the modal analysis of the elastic systems, the effects of the actuator positions, the input weighting factor and the magnitude of the constraint of the actuator force are investigated.

• 재활복지
• /
• 제21권1호
• /
• pp.253-277
• /
• 2017

이 연구는 지체장애인의 운동참여제약을 측정할 수 있는 운동참여제약 측정도구(Constraints in Physical Activity Scale for people with physical Disabilities: CPASD)를 개발하는 데에 목적이 있다. 이를 위해 이 연구에서는 Messick(1995)의 통합적 타당도, Benson(1998)의 강력한 구인타당도 프로그램 틀을 기반으로 한 다섯 가지 단계로 연구를 설계하였고, 지체장애인 264명을 대상으로 공통요인모형과 측정모형을 적용하여 CPASD의 타당도 증거를 체계적으로 제시하였다. 이 연구의 결과와 논의를 토대로 결론을 제시하면 다음과 같다. 첫째, CPASD는 구인타당도의 증거를 제시하였다. 요인구조의 해석가능성과 요인계수의 적합성을 통해 지도자 제약, 경제적 제약, 편견, 운동환경 제약으로 구성된 4요인, 17개 문항으로 개발되었다. 둘째, 개발된 CPASD의 요인구조(지도자제약, 경제적제약, 편견, 운동환경제약)는 통계적으로 구분됨과 동시에, 기존 운동참여제약 관련 이론을 안정적으로 반영하였다. 셋째, 개발된 CPASD는 준거관련타당도 증거를 제시하였다. 지도자제약, 편견은 긍정적 운동정서와 부적인 상관관계를, 지도자제약, 편견, 운동환경제약은 부정적 운동정서와 정적인 상관관계를 나타내었다. 따라서 후속 연구에서는 CPASD의 요인로 도출된 지도자제약, 경제적제약, 편견, 운동환경제약과 관련된 현재의 제도, 실태 등을 재평가할 필요성이 대두되고, 이를 위해 CPASD를 활용한 인과관계검증, IRT 이론을 적용한 현실 수준정도를 판단할 필요가 있다.