• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.3
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• pp.17-31
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• 2007

In this paper, we consider a service system with bi-functional servers, which can switch between the primary service room and the secondary room. A service policy is characterized by the switching paints which depend on the queue length in the primary service room and the service level requirement constraint of the secondary room. The primary service room is modeled as a Markovian queueing system and the throughput of the primary service room is function of the total number of bi-functional servers. the buffer capacity of the primary service room, and the service policy. There is a revenue obtained from throughput and costs due to servers and buffers. We study the problem of simuitaneously determining the optimal number of servers, buffer capacity, and service policy to maximize profit of the service system, and develop an algorithm which can be successfully applied with the small number of computations.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.11
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• pp.1038-1047
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• 2000

The objective of this study is to develop an optimized Artificial Neural Network(ANN) model to predict the descending time of room air temperature. For this, program for predicting room air temperature and ANN program using generalized delta rule were collected through simulation for predicting room air temperature. ANN was trained and the ANN model having the optimized values-learning rate, moment, bias, number of hidden layer, and number of neuron of hidden layer was presented.

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.3
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• pp.229-235
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• 1997

The comparison of radiative and convective heat transfer in a room air ventilation is investi¬gated by a numerical simulation. The room air temperature distributions with radiation are appeared more uniform than without radiation at Gr= 1460 and Re=50. The mean Nusselt number in the radiative heat transfer shows less value than convective heat transfer. The total mean Nusselt number is found Wall 1> Wall 3${\fallingdotseq}$Wall 2 7 Wall 4.

• Korea Journal of Hospital Management
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• v.28 no.3
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• pp.39-46
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• 2023

Purpose: Korean medical services are not balanced across regions and social classes. To prevent mortality gaps, Korea must distribute its medical resources more efficiently. Patient factors affecting emergency room visits serve as basic data for determining best practices for public healthcare distribution. Methods: The data included 18 473 visits by 14 949 de-identified patients who visited a public emergency room over one year. The dependent variable was the number of emergency room visits. A Poisson regression was conducted with the independent variables, comprising sociodemographic, socioeconomic, and spatial accessibility factors and patient characteristics. Results: Older men with higher Korean Triage and Acuity Scale scores visited more frequently. Greater patient-hospital distance decreased visits; however, the presence of a hospital within 1 km of a patient's residence did not affect the number of visits. The use of 119 services was negatively correlated with the number of visits. Visits increased with more medical benefits. Conclusions: Patient age, distance to hospital, use of 119 services, and medical benefits should be considered when planning or managing public hospitals in Korea.

• Journal of the Korean housing association
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• v.12 no.4
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• pp.43-52
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• 2001

The purpose of this study is to fined out the characteristics of using & change of the residential space according to the children age and family life cycle. The results of this study are as follows: The first, as children grow up, children's activity space changed from living room to the private room, and housing condition was related to the frequency of each activity. The second, as children grow up, family's sleeping pattern changed, and this change effected the number of private rooms for sleeping and the use of the extra room. The third, changes of the using of dwelling space come out several pattern, increasing bedroom number through reconstruction, exchange of An-band and children room, parents' sleeping space move to living room, and change the function of rooms. The change pattern of the correspondence to the housing needs differed from each family life cycle stage.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.3 no.5
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• pp.376-385
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• 1991

The purpose of this paper is to propose basic data on convection heat-transfer coefficients in Ondol-heated room. Surface temperatures and several temperatures around each inside surface of wall, floor and ceiling composed of heating room are measured vertically in Ondol-heated model rooms, and the vertical temperature profiles could be expressed by nonlinear equation models. Also, the convection heat transfer phenomena are analysed from the nonlinear equation models. In the results, the convection heat-transfer coefficients of Ondol heated space are suggested by the term of temperature difference between each wall surface and room air temperature and by the relationship between Nusselt number and Rayleigh number of dimensionless numbers.

• Journal of the Korean housing association
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• v.5 no.1
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• pp.29-45
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• 1994

The purpose of this study are to investigate the actual conditions of residing environment in children's room and it's utilization. Further, basic for the guidence and the effective preparation of children's room and children's residing environment in addition willbe produce through grasping the actual conditions of them.The subjects of this study were 214 5th grade elementary school children living in Taegu. The analysis of the data was done through SPSS pc programs.The major findings of this study can be summarized as follow;1. The greater part of children had their own room, and they had the desk, the book case and the clothes chest in their room. But the numbers of children with the bed were few in comparison to those. And a large number of children wanted to have the bed and the computer in their room.2. There were significant differences in the actual conditions of residing environcent in children’s room according to the independent variables. For example, the existence of children's room was variable according to farther's job(0.1% level).3. The case of having their own room in the period of the lower grades in elemtary school dccupied the highest percentage. A lage number of children passed away time mostly in the women'a guarters. In the cleaner of children's room, the case of doing themselves occupied the highest rate as 51 percent.4. There were significant differences in the actual conditions of utilization in children's room according to the independent variables. For example, the period of separation from their parents was variable according to mother's educational level(5%), father's job(0.1%)and the numbers of room(1%).

• Journal of Korean Physical Therapy Science
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• v.16 no.1
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• pp.31-39
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• 2009

Background: Community ambulation has been recently recognized as one of the most essential factors of activities of daily living in patients with post-stroke hemiparesis. This study aimed to compare walking velocity and step number in 5 community situations in patients with post-stroke hemiparesis. Methods: Ten chronic stroke patients volunteered for this study. The main variables analyzed were walking speed and step number, and these were measured in 5 different community situations: a physical therapy room, a parking lot, a bank, a crosswalk, and a hospital lobby. The measurements obtained for walking in the physical therapy room were measured using a 10m walk test and were used as baseline data for comparison with each option. The ambulation distance was set at 300m for the parking lot and the bank and 150m for the crosswalk and hospital lobby. For data analysis, walking speed and step number were standardized with the distance options of each ambulation. Results: Compared to the walking speed in the physical therapy room, those in the other situations, except for the parking lot, were significantly different (p<.05). Moreover, there were significant differences in the speeds between the bank and the parking lot and between the parking lot and the crosswalk (p<.05). Compared to the step number in the physical therapy room, those in all situations except for the crosswalk were significantly different (p<.05). Further, there was a significant difference in the step number between the bank and the crosswalk (p<.05). Conclusion: The walking ability of patients with hemiparesis in real environments within a community could be different from that in a physical therapy room. Therefore, the evaluation of walking should be performed in a variety of community situations.

• Journal of the Korean housing association
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• v.14 no.5
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• pp.75-82
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• 2003

In this study, the thermal performance of the room control system is analyzed in terms of control performance, potential for coil expansion and energy consumption through experiments comparing the individual room control system and an existing system. The results of this study show that the existing system is not able to supply design water flow rate and does not accurately maintain the set point temperature in each room. However, the individual room control system can set a room air temperature for each room, for it is able to supply design water flow and accurately control the set point temperature in each room and can reduce the energy consumption compared to the existing system. Moreover, the individual room control system can reduce the number of coil division zone and facilitates the construction process, because it can extend the length of the coil division.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1990.04a
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• pp.163-170
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• 1990

Clean rooms are widely used in high technology industries. Currently within the microelectronics industry there is an explosive growth in the number of clean rooms. Therefore, special consideration of clean room workers is needed to the work induced stresses from contamination avoidance, clothing requirements, and confinements [1].