• Journal of KIISE:Databases
• /
• v.36 no.5
• /
• pp.374-385
• /
• 2009

Flash memory becomes increasingly popular as data storage for various devices because of its versatile features such as non-volatility, light weight, low power consumption, and shock resistance. Flash memory, however, has some distinct characteristics that make today's disk-based database technology unsuitable, such as no in-place update and the asymmetric speed of read and write operations. As a result, most traditional disk-based database systems may not provide the best attainable performance on flash memory. To maximize the database performance on flash memory, some approaches have been proposed where only the changes made to the database, i.e., logs, are written to another empty place that has born erased in advance. In this paper, we propose an efficient log management scheme for flash-based database systems. Unlike the previous approaches, the proposed approach stores logs in specially allocated blocks, called log blocks. By evenly distributing logs across log blocks, the proposed approach can significantly reduce the number of write and erase operations. Our performance evaluation shows that the proposed approaches can improve the overall system performance by reducing the number of write and erase operation compared to the previous ones.

• Journal of The Korean Digital Architecture Interior Association
• /
• v.11 no.4
• /
• pp.5-11
• /
• 2011

The present study investigated the actual conditions of physical therapy rooms at long-term hospitals in Korea and conducted a comparative analysis to develop an efficient floor plan and facility improvement measures. 1. At hospitals surveyed, physical therapy services were used at a high frequency but they did not have enough space for rehab treatment and long paths of patient flow were found to make patient management inconvenient. Therefore, physical therapy units should be conveniently located both in terms of distance and direction so as to be accessible from patient rooms or wards. The space should be organized in a concentrated layout for efficiency of physical therapy, and floor planning for therapy units should ensure the best possible viewing angle to therapists. 2. With regard to the disease characteristics of patients, many physical therapy rooms were in difficult circumstances because of poor facilities, so they need to secure skilled personnel, supplement apparatuses and equipment and have rooms for functional recovery, hydrotherapy and operation treatment. In addition, each of the curtained or partitioned areas for treatment should be set up with consideration for the amount of space taken up by medical equipment. The area under each bed should be designed for patient convenience so that it can be used as storage space for patient's belongings and shoes. 3. Patients complained about the lack of physical therapy space, resting places or exercise areas and demanded the expansion of rehab programs and facilities. Physical therapy facilities need to be improved for patient privacy and effective natural ventilation. 4. At most of the long-term hospitals surveyed, physical therapy units were found to have small areas and treatment equipment and devices were insufficient compared to the number of patients. Therefore, it is required to secure more space (at least 138.24 sq. meters per 100 beds) and improve facilities for better physical therapy services.

• Journal of Preventive Medicine and Public Health
• /
• v.24 no.3 s.35
• /
• pp.400-413
• /
• 1991

The purpose of this paper is to identify factors affecting the optimum mix of required inputs and other relevant factors which account for the variation in physician's productivity in general hospitals, and to find out their implications for the efficient health planning and management. An extended version of Cobb-Douglas production function and cross sectional data of one day patient census from all general hospitals in Korea in 1988 were used in the analysis. Main results of the analysis and their implications could be summarized as follows : (1) The production function for physician's inpatient service shows the evidence of economies of scale, but the production function for physician's outpatient and adjusted-patient service, which combines both out- and in-patient service, shows that of dis-economies of scale. (2) The physician's role for production for all service is smaller than auxiliary personnel's, which imply that more intensive utilization of nurses, nursing aides and other auxiliary personnel is desirable for improving general hospital productivity (3) In case of physician's inpatient and adjusted-patient service, nurses' role is greater than nursing aides'. Therefore, more extensive utilization of nurses is recommended for the efficient operation of general hospitals. (4) The factor of hospital beds plays the leading role among required inputs in the production for physician's in- and adjusted-patient service. (5) The physician's productivity of general hospitals in rural area is lower than that in urban area. And the productivity of teaching hospitals is lower than that of the other hospitals. Further analysis was made in physician production function based upon the size of hospitals, namely those hospitals below 250 beds and those above. Explained variances by the factor of hospital beds was significantly increased in the case of those hospitals above 250. A more detailed and thorough investigation is needed for verifying factors influencing physician's productivity in general hospitals in Korea.

• Journal of the Korea Society of Computer and Information
• /
• v.16 no.9
• /
• pp.107-114
• /
• 2011

Because of boost of communications devices furnishing diverse services and rapid expansion of mobile business, good use and management of the existing network system become very important. Also, offering service corresponding with user communication requirement grades which vary widely in each person, is vital for communication service provider. In this paper, SGOSST, a mechanism of efficient network construction with minimum cost for network QoS is proposed. In experiments, though spending 252.97% more execution times, our SGOSST QoS network consumed 5.11% less connecting costs than the network constructed by weighted minimum spanning tree method. Therefore our mechanism can work well for efficient operation and service providing in the network formed with users and communication devices of various service requirement grade as smart/mobile equipment.

• Journal of Korean Society for Geospatial Information Science
• /
• v.17 no.2
• /
• pp.133-143
• /
• 2009

Next Generation Digital Maps on demand Updating System is a system for setup of efficient on-demand updating system, keeping up-to-date data and conducting high-quality service and efficient management. The system is designed that object-based continuous Digital Maps may have on-demand updating available, as well as the exiting feature-based digital maps, and the relevant development is being done. This study presented some problems and improvement plans related to the system operation, by means of implementing object-based continuous Digital Maps and feature-based digital maps updating test, for the next generation digital maps on demand updating system, in order to contribute to present plans to apply next generation digital maps and to secure competitiveness. And, for the economical efficiency of the next generation digital maps on demand updating system, this study analyzed expenses and benefit resulted from introduction of on demand updating system for 1:5,000 digital maps, intended for National Geographic Information Institute. and the land category which have an effect on the officially assessed land price and it using GIS technology.

• Journal of the Korean Society for Precision Engineering
• /
• v.20 no.2
• /
• pp.94-103
• /
• 2003

In case of environment requiring safety such as human body and requiring flexible shape, a conventional mechanical actuator system does not satisfy requirements. Therefore, in order to solve these problems. a research of various smart material such as EAP (Electro Active Polymer), EAC (Electro Active Ceramic) and SMA (Shape Memory Alloy) is in progress. Recently, the highest preferring material among various smart material is EP (Electrostictive Polymer), because it has very fast response time, powerful force and large displacement. The previous researches have been studied properties of polymer and simple control, but present researches are studied a polymer actuator. An EP (Electostrictive Polymer) actuator has properties which change variably ils shape and environmental condition. Therefore, in order to coincide with a user's purpose, it is important not only to decide a shape of actuator and mechanical design but also to investigate a efficient controller. In this paper, we constructed the control logic with an adaptive fuzzy algorithm which depends on the physical properties of EP that has a dielectric constant depending on time. It caused for a sub-actuator to operate at the same time that a sub-actuator system operation increase with a functional improvement and control efficiency improvement in each actuator, hence it becomes very important to manage it effectively and to control the sub-system which Is operated effectively. There is a limitation on the management of Main-host system which has multiple sub-system, hence it brings out the Multi-Vehicle Control process that disperse the task efficiently. Controlling the multi-dispersion system efficiently, it needs the research of Main-host system's scheduling, data interchange between sub-actuators, data interchange between Main-host system and sub-actuator system, and data communication process. Therefore in this papers, we compared the fuzzy controller with the adaptive fuzzy controller. also, we applied the scheduling method for efficient multi-control in EP Actuator and the algorithm with interchanging data, protocol design.

• Fire Science and Engineering
• /
• v.30 no.4
• /
• pp.148-157
• /
• 2016

The purpose of this study is to investigate the influence of organizational culture to the activities satisfaction of volunteer firefighter. For that, we surveyed 182 volunteer firefighters worked in Sejong city. The survey was analyzed the reliability in questionnaire design by SPSS 20.0 win program. The interrelationship of each factors were confirmed by analysis of frequency, percentage and regression analysis. The regression analysis was performed in order to investigate effects of group, development, hierachy, and rationality culture based organizational culture on activities satisfaction of volunteer firefighter. A factor of group and development culture in organizational culture was found to be a positive influence on the activities satisfaction of the volunteer firefighter under significance probability of < 0.05. The bigger group and development culture the volunteer fire department, the higher the activities satisfaction of the volunteer firefighter. This paper is expected to serve as a basis for the efficient operation of the volunteer fire department in Korea.

• Journal of Information Technology Services
• /
• v.16 no.4
• /
• pp.15-31
• /
• 2017

This study analyzes 45 Korea IT service companies from 2012 to 2016 using DEA analysis. Large enterprises, medium enterprises and small and medium enterprises (SMEs). CCR model and BCC model were used for efficiency analysis. Among the various analytical objects, the decision objects which yield the maximum output with minimum input are compared with other analysis objects. The relative inefficiency was measured through this, and Technical Efficiency (TE), Pure Technology Efficiency (PTE), Scale Efficiency (SE), scale profit, reference frequency were analyzed. Also, we analyzed the Technology Gap Ratio (TGR), which is the distance between production function and Meta-Frontier for each firm, using Meta-Frontier analysis. Finally, the Tobit model is used to analyze the sources of efficiency and inefficiency. The inputs are assets, capital, and employees, and the output factor is sales. The analysis shows that large firms are achieving technological achievements more efficiently than small and medium enterprises. As a result, medium-sized enterprises and SMEs can improve efficiency overall through efficient operation of workforce and appropriate combination of inputs such as assets and capital. Also, as a result of the influence factor analysis, it was found that the ratio of the managed asset ratio and the management cost ratio were significant factors influencing the efficiency of the IT service companies. This study suggests the efficiency analysis using DEA for many Korea IT service companies. Inefficient parts of each company are classified according to size and technology. Also, we identify the most efficient companies and analyze the causes of those companies whose profits are lower than their size.

• Journal of Digital Convergence
• /
• v.9 no.1
• /
• pp.177-187
• /
• 2011

Along with recent rapid growth in social media and mobile media in the web 2.0 flow, represented as openness, participation, and sharing, general and various changes are essential not only in economical, social, and cultural aspects, but also in politics. Korea is finding its position in leading the upcoming social media market based upon the past IT technologies. In the past years, the people of Korea have drawn attention in the international society as early adopters in new IT products. In the current dynamic varying social media environment, the politics must put efforts to utilize a method emphasing on communication with the people. Efforts to change are essential to modify the vision of organization as smart citizens party and implement the social media strategy. In this study, we investigate and suggest methods to change in the social media environment maintaining close relation with the people in order to unite with them. Our reports will help to revisit the existing government/party operation and to rethink about the efficient operating strategy suitable for social media environment.

• Journal of Korean Society on Water Environment
• /
• v.24 no.5
• /
• pp.581-591
• /
• 2008

Most of our rivers are fragmented by the presence of at least one large dam. Dams are often the most substantial controller of the flow regimes and aquatic environments of natural river system. The quality of downstream water released from a stratified reservoir is highly dependent on upstream reservoir water quality. Thus, an integrated modeling approach is more efficient, compared to fragmented modeling approach, and necessary to better interpret the impact of dam operation on the down stream water quality. The objectives of this study were to develop an integrated reservoir-river modeling system for Daecheong Reservoir and its downstream using a two-dimensional laterally averaged hydrodynamic and water quality model, and evaluate the model's performance against field measurement data. The integrated model was calibrated and verified using filed data obtained in 2004 and 2006. The model showed satisfactory performance in predicting temporal variations of water stage, temperature, and suspended solid concentration. In addition, the reservoir-river model showed efficient computation time as it took only 3 hours for one year simulation using personal computer (1.88 Ghz, 1.00 GB RAM). The suggested modeling system can be effectively used for assisting integrated management of reservoir and river water quality.