• 가정과삶의질연구
• /
• 제22권4호
• /
• pp.157-171
• /
• 2004

In this study, adolescent consumers were first classified by their consumption propensity, and different types of adolescent consumers were compared regarding their consumption behavior and allowance management. The adolescents were classified into four groups by type of control and symbol-orientation. The adolescents of the external control group possessed more commodities than the internal control group. There were significant differences in the patterns of allowance management in the four groups. The low-external symbol group owned more commodities than high-external symbol group. The high-external symbol group considered external appearance more important when purchasing commodities.

• 대한의용생체공학회:의공학회지
• /
• 제26권6호
• /
• pp.357-363
• /
• 2005

Active contour models have been extensively used to segment, match, and track objects of interest in computer vision and image processing applications, particularly to locate object boundaries. With conventional methods an object boundary can be extracted by controlling the internal energy and external energy based on energy minimization. However, this still leaves a number of problems, such as initialization and poor convergence in concave regions. In particular, a contour is unable to enter a concave region based on the stretching and bending characteristic of the internal energy. Therefore, this study proposes a method that controls the internal energy by moving the local perpendicular bisector point of each control point on the contour, and determines the object boundary by minimizing the energy relative to the external energy. Convergence at a concave region can then be effectively implemented as regards the feature of interest using the internal energy, plus several objects can be detected using a multi-detection method based on the initial contour. The proposed method is compared with other conventional methods through objective validation and subjective consideration. As a result, it is anticipated that the proposed method can be efficiently applied to the detection of the pulmonary parenchyma region in medical images.

• International Journal of Control, Automation, and Systems
• /
• 제6권4호
• /
• pp.515-525
• /
• 2008

In this paper, the problem of delay-dependent stabilization for singular systems with multiple internal and external incommensurate constant point delays is investigated. The condition when a singular system subject to point delays is regular independent of time delays is given and it can be easily test with numerical or algebraic methods. Based on Lyapunov-Krasovskii functional approach and the descriptor integral-inequality lemma, a sufficient condition for delay-dependent stability is obtained. The main idea is to design multiple memoryless state feedback control laws such that the resulting closed-loop system is regular independent of time delays, impulse free, and asymptotically stable via solving a strict linear matrix inequality (LMI) problem. An explicit expression for the desired memoryless state feedback control laws is also given. Finally, a numerical example illustrates the effectiveness and the availability for the proposed method.

• 한국수학교육학회지시리즈E:수학교육논문집
• /
• 제34권3호
• /
• pp.325-354
• /
• 2020

수학 학업성취도에 영향을 미치는 요인들은 매우 다양하며, 그 요인들이 미치는 영향 또한 복합적으로 일어난다. 수학 학업성취도에 영향을 미치는 요인들은 끊임없이 변화하고 발전하기 때문에 학습자들의 성장을 예측하고 분석하는 종단연구가 필요하다. 본 연구는 서울교육종단연구의 2013년도(중학교 1학년)부터 2017년(고등학교 2학년)까지의 종단자료를 활용하여 내적요인(자아개념, 자기통제, 삶의 만족에 대한 자기평가), 외적요인(학교풍토, 자녀에 대한 보호자의 관심, 보호자의 학습조력)의 변화패턴을 알아보고 내·외적요인이 수학 학업성취도에 어떠한 영향을 미치는지 살펴보았다. 수학 학업성취도를 분석한 결과, 중학교 1학년부터 중학교 2학년까지의 수학 학업성취도는 변화가 없는 것으로 나타났으며, 중학교 2학년부터 고등학교 1학년까지는 꾸준히 증가하다가 고등학교 2학년 때는 소폭 하향하는 것으로 나타났다. 내적요인인 자아개념과 자기통제는 중학교 1학년부터 중학교 2학년까지는 소폭 떨어지다가 고등학교 1학년까지는 소폭 증가하고 고등학교 2학년에는 소폭 떨어지는 것으로 나타났으며, 삶의 만족에 대한 자기평가는 중학교 1학년부터 고등학교 2학년까지의 기간 동안 소폭 떨어지는 것으로 나타났다. 외적요인 중 학교풍토는 중학교 1학년부터 중학교 2학년까지는 소폭 떨어지는 것으로 나타났으며, 고등학교 1학년까지는 증가하다가 고등학교 2학년에는 그 값이 유지되는 것으로 나타났다. 자녀에 대한 보호자의 관심은 중학교 1학년 때의 값이 고등학교 2학년까지 유지되는 것으로 나타났으며, 보호자의 학습조력은 중학교 1학년부터 지속적으로 감소하는 것으로 나타났다. 수학 학업성취도에 대한 영향을 알아보기 위해 임의 기울기 모델(Random Slope Model)을 시행한 결과 내적요인인 자아개념 및 자기통제, 그리고 외적요인인 학교풍토가 수학 학업성취도의 변화에 영향을 미치는 것으로 나타났다.

• 에너지공학
• /
• 제23권4호
• /
• pp.183-188
• /
• 2014

Solenoid operated electromagnetic control valve (ECV) using in an external variable displacement swash plate type compressor is widely used for air conditioning control system because of its low energy consumption and high efficient characteristics. ECV controls the entire vehicle air conditioning system by means of a pulse width modulation (PWM) system that supplied from an external controller. Different pressure ports located within ECV has important functions to control the air/refrigerant flow through its internal passages. The flow paths are preciously maintained with acceptable ranges of leakage (gap) between the parts inside it which is followed by effective design and critical dimensioning of its internal features. Therefore, it saves energy losses from the solenoid operation as well as ensures the balance of forces within it. The research paper highlights analysis of the leakages (at different pressure ports) and dimensioning tolerance factors that affects the ECV performance.

• 아동학회지
• /
• 제23권3호
• /
• pp.1-15
• /
• 2002

The subjects of this study were 4th to 6th grade children and instruments were the Teenage Inventory of Social Skills, the Internal-External Control Scale, the Self-Esteem Scale, and the Peer Relations Questionnaire. In the concurrent study, children lower in social skills and in self-esteem and external in locus of control reported more bullying and victimization. Children higher in social skills and in self-esteem and internal in locus of control reported more prosocial behavior. In the prospective study, children lower in social skills were more involved in bullying and victimization. Children higher in social skills reported more prosocial behavior. The effects of locus of control and self-esteem on peer relations diminished over time. However, social skills had a significant influence on bullying, victimization and prosocial behavior up to two years later. Children lower in psychosocial development were more vulnerable to peer victimization.

• 대한안전경영과학회지
• /
• 제13권2호
• /
• pp.185-193
• /
• 2011

The successful and sustainable growth of SMEs depends on their ability of strengthen their competitiveness in quality and cost and service more than anything else as a fundamental of operation. Among these key competitive factors of SMEs, quality is the most critical factor in manufacturing business fields. There are many different ways to improve the quality performance but it needs proper management decision to choose the best way what can maximize outputs with minimum inputs. And it needs effective measurement methods and some indicators to analysis the quality performance properly. The quality cost is one of the simplest key indicators to measure the quality performance and the effectiveness of quality related management decisions. In this study, through survey on local SMEs, we found that their average annual quality cost ratio versus turnover - total amount of annual quality cost divided by annual turnover - is around 3.69% excluded some SME's performances what have different quality control measures with others. And we found some results what corresponded with the early studies on the correlations between those categorized quality costs factors and some discrepancies between some of the literature model and the early case study results as follows. There were negative correlations between the Prevention costs and the External failure costs, and the Appraisal costs and the External failure costs, and there was positive correlation between the Appraisal costs and Internal failure costs same as early studies. But, we couldn't found any strong negative correlations between the Cost of control - Prevention costs & Appraisal costs - and the Cost of Failure of control - Internal & External failure costs -.

• Smart Structures and Systems
• /
• 제26권5호
• /
• pp.575-589
• /
• 2020

For vibration control of stay cables in cable-stayed bridges, viscous dampers are frequently used, and they are regularly installed between the cable and the bridge deck. In practice, neoprene rubber bushings (or of other types) are also widely installed inside the cable guide pipe, mainly for reducing the bending stresses of the cable near its anchorages. Therefore, it is important to understand the effect of the bushings on the performance of the external damper. Besides, for long cables, external dampers installed at a single position near a cable end can no longer provide enough damping due to the sag effect and the limited installation distance. It is thus of interest to improve cable damping by additionally installing dampers inside the guide pipe. This paper hence studies the combined effects of an external damper and an internal damper (which can also model the bushings) on a stay cable. The internal damper is assumed to be a High Damping Rubber (HDR) damper, and the external damper is considered to be a viscous damper with intrinsic stiffness, and the cable sag is also considered. Both the cases when the two dampers are installed close to one cable end and respectively close to the two cable ends are studied. Asymptotic design formulas are derived for both cases considering that the dampers are close to the cable ends. It is shown that when the two dampers are placed close to different cable ends, their combined damping effects are approximately the sum of their separate contributions, regardless of small cable sag and damper intrinsic stiffness. When the two dampers are installed close to the same end, maximum damping that can be achieved by the external damper is generally degraded, regardless of properties of the HDR damper. Field tests on an existing cable-stayed bridge have further validated the influence of the internal damper on the performance of the external damper. The results suggest that the HDR is optimally placed in the guide pipe of the cable-pylon anchorage when installing viscous dampers at one position is insufficient. When an HDR damper or the bushing has to be installed near the external damper, their combined damping effects need to be evaluated using the presented methods.

• 대한토목학회논문집
• /
• 제32권4D호
• /
• pp.313-322
• /
• 2012

본 연구는 택시운수업 종사자의 위험성향을 위험감행행동과 교통 통제소재의 측면에서 분석하였다. 위험감행행동 측면의 분석을 위해 운전자의 위험감행성향의 위험감행행동에 대한 예측모형을 제시하였다. 이를 통해 운전자의 위험감행성향은 위험감행행동에 유의미한 영향을 주고 있음을 알 수 있었으며, 지각운전능력이 높고 준법의식이 결여될수록 위반행동을 많이 하는 것으로 나타났다. 둘째, 교통 통제소재(외적통제형, 내적통제형)에 따라 위험감행 수준의 차이가 있는지 다변량 분석을 통해 알아보았다. 외적통제형(External Control) 운전자의 경우 위험감행수준이 높고 내적통재형(Internal Control)의 경우 위험감행수준이 낮게 분석되어 사고책임을 귀인(歸因)하는 태도에 따라 위험감행성향에 차이가 있는 것을 볼 수 있었다. 본 연구에서 구조방정식 모형을 통해 구축한 위험감행성향과 관련된 위험감행 예측모형에서 ${\chi}^2$값은 279.7, ${\chi}^2$/df=1.55, RMSEA=.44, GFI=.911, TLI=.916, CFI=.929로 적합한 부합도를 보이고 있다.

• PNF and Movement
• /
• 제12권1호
• /
• pp.33-37
• /
• 2014

Purpose: In this research, the properties of the shoulder joint were measured through eccentric resistive exercise with the patients who have rotator cuff tear of shoulder joints as the targets. Methods: 23 patients who have pain due to the rupture of rotator cuff on shoulder joints were selected and divided into Exercise group (12) and Control group (11). Two groups executed exercise for 30 minutes 3 days a week. Exercise group had executed eccentric resistive exercise, and the Control group executed Complex exercise. Results: In external rotation $180^{\circ}/s$, $240^{\circ}/s$, the Exercise group showed to be an average of 8% higher than the Control group. For Internal rotation $90^{\circ}/s$, $180^{\circ}/s$, $240^{\circ}/s$ the Exercise group showed to be an average of 30% higher that the Control group. Conclusion: To lessen the rupture of rotator cuff on shoulder joints, muscles strengthening is very important across various methods of eccentric exercise programs which are external/internal rotators of the shoulder joint needed for throwing. This is effective in preventing injury and improving rotation.