• The Journal of the Korea Contents Association
• /
• v.15 no.1
• /
• pp.242-251
• /
• 2015

The purpose of this study was to explore leisure constraints and the strategies to overcome leisure constraints of career women, and to examine the difference in leisure constraints and leisure constraints negotiation strategies between married and unmarried career women. In Seoul, a total of 440 career women selected using the cluster quota sampling method participated in the current study. Finally, 433 responded data with the exception of 7 unreliable surveys were employed for the analyses such as frequency, exploratory factor, reliability analysis, and t-test. Main findings were as follows; First, six factors including interpersonal, intrapersonal, time, expense and information, environmental, and physical constraints were extracted for career women. Environment and time commonly constrained their participation in leisure activities the most. Second, five factors including skill acquisition, finding alternative activity, control intensity, finding partners, and financial and time management strategies were extracted for them. Third, there were the differences in time and physical constraints between two groups and married career women's constraints were higher than singles. Finally, there was the difference in skill acquisition strategy and married career women's it was higher than the other group.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.29B no.11
• /
• pp.36-45
• /
• 1992

A numerical trajectory planning method for path-constrained trajectory planning is proposed which ensures collision-free and time-optimal motions for two robotic manipulators with limited actuator torques and velocities. For each robot, physical constraints of the robots such as limited torques or limited rotational velocities of the actuators are converted to the constraints on velocity and acceleration along the path, which is described by a scalar variable denoting the traveled distance from starting point. Collision region is determined on the coordination space according to the kinematic structures and the geometry of the paths of the robots. An Extended Coordination Space is then constructed` an element of the space determines the postures and the velocities of the robots, and all the constraints described before are transformed to some constraints on the behaviour of the coordination-velocity curves in the space. A dynamic programming technique is them provided with on the discretized Extended Coordination Space to derive a collision-free and time-optimal trajectory pair. Numerical example is included.

• Journal of the Korean Home Economics Association
• /
• v.43 no.4 s.206
• /
• pp.203-223
• /
• 2005

This study investigated the leisure constraints and leisure life satisfaction of the institutional elderly. The respondents were 302 elderly people residing in 5 free institutionalized elderly homes in Seoul. The data were analyzed by frequency analysis, factor analysis, One-way ANOVA, Duncan's post hoc test and regression analysis using SPSS WIN 12.0 program. Exploratory factor analysis revealed that the 10 items in the proposed scale could be grouped into four factors of constraint on leisure:'physical constraint','psychological constraint','interpersonal constraint', and 'structural constraint 'There were differences in leisure constraints according to sex, age, education degree, interaction with facility colleagues, and interaction with facility staff. There were differences in leisure life satisfaction according to sex, age, having religion or not, interaction with facility colleagues, interaction with facility staff and leisure constraints. Regression analysis results indicated that the main effective factors of leisure life satisfaction were leisure constraints.

• Industrial Engineering and Management Systems
• /
• v.16 no.1
• /
• pp.141-153
• /
• 2017

A binary integer programming model is proposed for a complex timetabling problem in a university faculty which conducts various degree programs. The decision variables are defined with fewer dimensions to economize the model size of large scale problems and to improve modeling efficiency. Binary matrices are used to incorporate the relationships between the courses and students, and the courses and teachers. The model includes generally applicable constraints such as completeness, uniqueness, and consecutiveness; and case specific constraints. The model was coded and solved using Open Solver which is an open-source optimizer available as an Excel add-in. The results indicate that complicated timetabling problems with large numbers of courses and student groups can be formulated more efficiently with fewer numbers of variables and constraints using the proposed modeling framework. The model could effectively generate timetables with a significantly lower number of work hours per week compared to currently used timetables. The model results indicate that the particular timetabling problem is bounded by the student overlaps, and both human and physical resource constraints are insignificant.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.10
• /
• pp.6575-6583
• /
• 2015

The purpose of this study was to investigate the relationship among leisure constraints, athletic life satisfaction and self-control of student athletes at physical education high school. By using convenience sampling method of non-provability sampling, a total 217 students athletes from D and G city were selected. Of 217 copies of the questionnaire gathered, 35 were discarded owing to having excessive missing values. Thus by analysing a total of 182 surveys with structural equation modeling through SPSS 20.0 statistics program, this study found the followings. First, leisure constraints have a negative influence on athletic life satisfaction. Second, leisure constraints have a negative influence on self-control. Third, athletic life satisfaction has a positive influence on self-control.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.1181-1184
• /
• 1996

As usual systems, robot manipulators have also physical constraints for operating. It is a difficult problem that we operate manipulator in the minimal time under these constraints. In this paper, we solve this problem dividing it into two steps. In the first step, we find the minimal time trajectories by optimizing qubic polynomial joint trajectories using evolutionary algorithms. In the second step, we optimize controller for robot manipulator to track precisely trajectories optimized in the previous step.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2004.03a
• /
• pp.617-621
• /
• 2004

Miniaturization of subsystems including propulsion systems is recent trends in spacecraft technology. Small space vehicle propulsion is not only a technological challenge of a scaling system down, but also a combination of fundamental flow/combustion constraints. In this paper, physical constraints of micronozzle for cold gas micro-thruster are reviewed and discussed. Method to measure small thrust are also described.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.1901-1904
• /
• 2003

MPC or model predictive control is representative of control methods which are able to handle physical constraints. Closed-loop stability can therefore be ensured only locally in the presence of constraints of this type. However, if the system is neutrally stable, and if the constraints are imposed only on the input, global aymptotic stability can be obtained; until recently, use of infinite horizons was thought to be inevitable in this case. A globally stabilizing finite-horizon MPC has lately been suggested for neutrally stable continuous-time systems using a non-quadratic terminal cost which consists of cubic as well as quadratic functions of the state. The idea originates from the so-called small gain control, where the global stability is proven using a non-quadratic Lyapunov function. The newly developed finite-horizon MPC employs the same form of Lyapunov function as the terminal cost, thereby leading to global asymptotic stability. A discrete-time version of this finite-horizon MPC is presented here. The proposed MPC algorithm is also coded using an SQP (Sequential Quadratic Programming) algorithm, and simulation results are given to show the effectiveness of the method.

• Journal of the Society of Naval Architects of Korea
• /
• v.53 no.1
• /
• pp.54-61
• /
• 2016

This paper defines the design constraint in consideration of the dynamic characteristics and stability in the longitudinal direction of a supercavitating vehicle. Available range of the design variables is calculated by numerical simulation and the cavity modeling of vehicle dynamics is performed first. Configuration parameters of the supercavitating vehicle to determine the vehicle dynamics and characteristics of the cavity are defined as design variables. Design constraints are supercavitation, trim velocity, stability and vehicle dynamics in transition phase. Numerical results show that in accordance with the change of the design variables, the proposed design constraints reflect the physical characteristics of the supercavitating vehicle. This research finds the design region where the constraints of supercavity and the trim velocity are satisfied, and the stability analysis refines the design results by excluding the region where the stability is not guaranteed. The stability analysis is particularly important for a vehicle with the short fin span.

• Health Policy and Management
• /
• v.33 no.4
• /
• pp.389-399
• /
• 2023

Background: The purpose of this study is to analyze the factors affecting the unmet healthcare needs of older people with chronic diseases in Korea and provide a basic research report to strengthen their access to medical care. Methods: In the 2020 older people survey data, 8,182 older people aged 65 or older who were diagnosed with one or more chronic diseases were the final subjects of the study. According to Andersen's behavioral model used in unmet healthcare needs, independent variables were composed of predisposing factors, possible factors, and necessary factors, and whether or not unmet healthcare needs was set as dependent variable. Results: Of the older people with chronic diseases, 1.6% experienced unmet healthcare needs, of which 55.9% experienced unmet healthcare needs for reasons related to economic burden, 31.6% physical constraints, and 12.5% time constraints. As a result of the analysis, older people with chronic diseases were more likely to experience unmet healthcare needs if they were relatively low in age, low in education level, no spouse, low in household income, poor subjective health, complex chronic diseases, and functional restrictions. However, by major reasons for experiencing unmet healthcare needs, living in rural areas were more likely to experience unmet healthcare needs due to physical constraints, and those who participated in economic activities and who had were more likely to experience unmet healthcare needs due to time burden. These results were not derived when only unmet healthcare needs was set as the dependent variable. Conclusion: This study emphasizes the need for an approach by cause of unmet medical occurrence by suggesting that there are differences in influencing factors by reason for experiencing unmet healthcare needs.