• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.11
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• pp.2199-2214
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• 1994

In order to sufficiently utilize the potential effectiveness of ATM networks, systematic and effective network management and control systems must be employed. In addition to network design, planning, and call routing techniques used in traditional circuit-switched networks. ATM networks can provide logical VP(Virtual Path) reconfiguration capabilities which can adapt to changes in the network environment. With a proper application of the VP reconfiguration technique, ATM networks can reduce the overhead of frequent network redesign and the overhead of call routing processing. However, ATM VP reconfiguration is a very complex and difficult problem which consists of many facets of optimization subproblems such as VP routing. VP sizing, VP terminating point location and VC routing. Most previous research on the ATM logical network reconfiguration problem dealt with the subset of the problem. This paper mathematically formulates the ATM network reconfiguration problem completely considering all subproblems. Since it is very difficult to derive the optimal solution of the formulated problem, we develop a heuristic method based on a Max min bandwidth allocation principle. We show the feasibility of the proposed heuristic method with a simple example.

• Journal of The Korea Institute of Healthcare Architecture
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• v.21 no.2
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• pp.17-24
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• 2015

Purpose: This study examines distance from nurse station to bed according to composition of single bedroom. Methods: This study has two groups of target sample ward planes. The first group has diverse patients bedroom. The other group is 36 single bedrooms and 2 3-bedrooms. The guideline of distance measurement was instituted for consistency. This study has 3 main concepts of the guideline. 1) The distance is shortcut from NS to bed. 2) The traffic line is center line between walls and center of door. 3) The start point is center of NS and the end point is bed. Results: The result of this study can be summarized into two points. The first one is that single bedroom has good privacy and longer distance from NS to bed. The second one is that weak point of single bedroom was asked ward operating system and architectural planning like as patients room, bed per unit, location of NS and plan type. Implications: Consideration Should be taken into account for the effective bedroom composition and allocation in ward. This Stuy hopefully serve as a stepping stone for the standard design of space program in ward planning.

• Journal of the Korean Association of Geographic Information Studies
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• v.4 no.4
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• pp.29-38
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• 2001

This study addresses the topic of suitability analysis for helping with land use planning, which is one of important decision-making in urban planning, utilizing geographic information system. Covering the Kumi City before integrating with neighbor county, the site suitabilities for land uses, which are categorized into residential, commercial, industrial and green, were analyzed using the overlay method based upon the database constructed for this study. In the process, assessment criteria which include environmental factors and relative weights were determined and also the land use/cover map and NDVI map which were generated through satellite image processing were included in the database. The suitability maps by four function spaces were derived according to the grade and compared with the present land use state and the land use concept map of urban master plan. For more accurate analysis, practical developing plan, land price data, soil data should be included. Also if the demand estimation data by each land use had been added, the reliability of location allocation could have been raised.

• Journal of the Korea Institute of Building Construction
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• v.11 no.3
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• pp.319-325
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• 2011

During a construction project, construction managers must be provided with material information to help them to make decisions more efficiently without delaying the delivery of material. Construction work can be smoothly performed with the proper material supply. Construction duration depends on several material-related decisions, including the order, delivery, and allocation of material to the correct work location. Hence, it is worthwhile to introduce data warehouse techniques that generate subject-oriented and integrated data to construction material management. The data warehouse for construction material management can perform multidimensional analysis and then define KPIs (Key Performance Index) in order to provide construction managers with construction material information such as lead time, material delivery rate, material installation rate and so on. This research proposes a method of effectively facilitating large amounts of data in the operating systems during the construction management process. In other words, the proposed method can supply structured and multi-perspective material-related information using data warehouse techniques.

• Journal of the Korean Regional Science Association
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• v.10 no.2
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• pp.17-29
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• 1994

This study attempts to examine the regional distribution and the locational pattern of leisure facilities at Kangnam-gu in Seoul. For the convenience of the analysis the facilities are classified into public and private sector and then the facilities are classified into 11 types: mineral spring resort, play ground, neighborhood park, swimming pool, gymnasium, bowling, pingpong, aerobic, golf practice, health, and billiard facilities. For the purpose data was collected from statistical yearbook in 1993 and lists of registered facility at department of living physics of Kangnam-gu office. The data of the density of facilities and the opportunity of facilities per facilities type and per region are analysed with the technology of GIS. Results may be summarized as follows. First of all, correlation between the results of Location-Allocation model and the results of Interaction model is very high. Secondly, on comparing the density of facilities with the opportunity of the facility use per eleven facility types, three discrete spatial pattems are found. The mineral spring resort facility type with the highest unbalanced density and opportunity of facility use is to be found. Play ground, neighborhood park, swimming pool, gymnasium, bowling, pingpong, and aerobic facility types have the high unbalanced density and opportunity of facility use. The golf practice, health, and billiard facility types have spatially balanced density and opportunity of facility use. Thirdly, as comparing the density and the opportunity of the facility use per 'dong' administration unit, the spatial patterns of the public and the private facilities are different in density of the facility use and otherwise two are similar in the opportunity of the facility use. Fourthly, patterns of facilities users have different charateristics based on facility use time, expense, residence, and access time and four regional patterns are to be found ; user favorable, facility profitable, user balanced, and unfavorable.

• Journal of Korean Society of Rural Planning
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• v.21 no.3
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• pp.145-154
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• 2015

With the rapid change of rural communities and increasing desire for social welfare, the demand for the quality of public spaces and facilities is increasing. However, inefficient location of rural public space and facility has caused problems such as economic inefficiency, inconvenient accessibility, environmental pollution, unsustainable energy use, and disturbance of visual landscape. This study aims to evaluate suitability of public spaces and facilities in three types of rural village: rural downtown village, rural clustered village, and individual village. As a way to measure the suitability of public spaces and facilities, we assessed indicators of suitability in terms of accessibility, usability, biophysical environment, and sustainable management. To evaluate the accessibility, we applied indicators such as distance from residential areas, public transit, market and public facilities. For the evaluation of biophysical environment, we applied indicators such as slope, elevation, aspect, and occurrence of natural disasters. We analyzed digital maps representing the indicators listed above using GIS. We also conducted a survey and face-to-face interviews to evaluate usability and sustainability of management which are not possible to understand through maps. As a result, we identified that suitability of public spaces and facilities in downtown villages is higher than clustered and individual villages. In particular, suitability of infrastructure facilities, social welfare facilities, and income generation facilities in downtown village are higher than those in clustered and individual villages. The suitability of tourism facilities is generally lower than other types of public facility across the three types of villages. Tourism facilities in clustered village have been identified especially unsuitable compared to other types of villages. We expect the outcome of the research is helpful to improve allocation of public spaces and facilities in rural villages.

• Journal of Communications and Networks
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• v.8 no.4
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• pp.451-460
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• 2006

Since low earth orbit (LEO) satellite constellations have important advantages over geosynchronous earth orbit (GEO) systems such as low propagation delay, low power requirements, and more efficient spectrum allocation due to frequency reuse between satellites and spotbeams, they are considered to be used to complement the existing terrestrial fixed and wireless networks in the evolving global mobile network. However, one of the major problems with LEO satellites is their higher speed relative to the terrestrial mobile terminals, which move at lower speeds but at more random directions. Therefore, handover management in LEO satellite networks becomes a very challenging task for supporting global mobile communication. Efficient and accurate methods are needed for LEO satellite handovers between the moving footprints. In this paper, we propose a new seamless handover management scheme for LEO satellites (SeaHO-LEO), which utilizes the handover management schemes aiming at decreasing latency, data loss, and handover blocking probability. We also present another interesting handover management model called satellite mobility pattern based handover management in LEO satellites (PatHO-LEO) which takes mobility pattern of both satellites and mobile terminals into account to minimize the handover messaging traffic. This is achieved by the newly introduced billboard manager which is used for location updates of mobile users and satellites. The billboard manager makes the proposed handover model much more flexible and easier than the current solutions, since it is a central server and supports the management of the whole system. To show the performance of the proposed algorithms, we run an extensive set of simulations both for the proposed algorithms and well known handover management methods as a baseline model. The simulation results show that the proposed algorithms are very promising for seamless handover in LEO satellites.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.8C
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• pp.645-654
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• 2012

In this paper, we consider a two-way relay (TWR) system, where two user nodes exchange their information within two transmission phases, by the help of a relay node adopting physical layer network coding. In the system, two users transmit their binary phase shift keying symbols simultaneously in the first phase, and the relay node decodes the XORed version of two user data and broadcasts it back to two users in the second phase. The performance of the system is analyzed in terms of the average end-to-end symbol error probability in Nakagami-m fading channels, for which a tight upper bound is derived in a closed form to provide an accurate and handy estimate on the performance. The results show that our upper bounds are almost indistinguishable from simulation results for various channel and system configurations. In addition, the optimal relay location and power allocation for various conditions can be obtained quickly with our analysis.

• Journal of The Korea Institute of Healthcare Architecture
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• v.24 no.2
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• pp.15-25
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• 2018

Purpose: The important things in space plan of a screening center are improving the spatial awareness by space systemization and minimizing the examination time for customers, and reducing the required time of screening work and maximizing the capacity for the screening center. Therefore, we tried to solve the problem of improving spatial awareness and reducing the examination time by using the pedestrian based discrete event simulation at the minimum cost. Methods: We have analyzed the drawbacks and the supplement points by comparing the floor plan at the time of opening and the current floor plan. Based on the analysis, we propose an improved plan which changes the location of the examination rooms and the number of services, and we also verify the improved plan based on simulation analyses. Results: 1) Through the analyses, we derived the drawbacks of the floor plan at the time of opening, and we realized that the current floor plan reflects the drawbacks. 2) The major reasons of the long examination time are the human traffic jam and the occurrence of queues due to unreasonable allocation of services. 3) Through the discrete event simulation analyses, it was possible to specify the place of the queues manually so as to use the given space fairly. 4) Using the discrete event simulation, it was possible to reduce the examination time and to improve the spatial awareness effectively at the minimum cost. Implications: Although the proposed simulation methodology in this paper is an analysis of the existing screening center, we expect that the proposed methodology will be used to develop a more efficient architectural design process by pre-applying the method to the course of designing a screening center and finding the suitability of the proposed method with the matched number of services.

• Journal of Korean Critical Care Nursing
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• v.6 no.2
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• pp.65-77
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• 2013

Purpose: The purpose of the study was to analyze the nursing activities related to continuous renal replacement therapy (CRRT) in the intensive care units (ICU). Methods: We developed a list of 31 CRRT related nursing activities based on literature review and reviewed by expert group. A total of 109 direct time measurement records by 43 ICU nurses were collected and analyzed in terms of total time per shift, frequency, standard time, difficulty and performance levels of each CRRT nursing activity. Results: The mean time for CRRT nursing activity was 85.60 minutes per 8 hour shift. Nurses have spent average $9.46{\pm}6.98$ minutes in a shift for "waste fluid bag change" activity. In addition, "check catheter location" was the most time consuming single activity. The most difficult activity was "counseling-answer" and the most competent one was "dialysis solutions change". Conclusion: The CRRT nursing activities accounted for a significant portion of total nursing workload. Practical allocation of nursing staff for CRRT patient along with development of a new nursing cost system need to be considered. Continuous nursing educational and training programs on CRRT should be developed.