• Journal of Korean Society for Geospatial Information Science
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• v.23 no.2
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• pp.69-77
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• 2015

In Korea, local governments have decided the location of shelters as part of their disaster planning. However, no quantitative standards, such as assuming different hazard and shelter types, shelters' capacity, are specified in that planning. To propose the direction of disaster evacuation policy, first of all, the current state of shelters' location and evacuation area is needed to be analyzed. In addition, considering topographical condition such as road slope and physical strength by age are important factors to measure optimal evacuation route. The purpose is to suggest a new methodology of estimating optimal evacuation route considering resistance of road slope and difference of walking speed by age. Moreover, as a case study of Seoul, Korea, using coverage analysis of GIS analysis tool, the accessible area (or vulnerable area) to the shelters is evaluated based on the spatial distribution of disaster evacuation shelters and their accommodation capacity, according to evacuation time within 7.5, 15 and 30 minutes. The main results are summarized as follows: 1) The average area of disaster evacuation shelter per person is calculated as 0.45 square meters. Considering that the minimum shelters' area per person is 1 square meters, only 45% of people in Seoul can be accommodated. 2) The ratio of inhabitants who live in accessible area within 7.5 minutes presents only 33% of all. Furthermore, the ratio of inhabitants by age group of 5~9 or over 65 years old shows significantly lower percentage in comparison with 15~49 years old people.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.3
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• pp.11-18
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• 2012

Increasing concern about biodiversity has lead to a rise in demand on the spatial assessment of biological resources such as biodiversity assessment, protected area selection, habitat management and restoration in Korea. The purpose of this study is to create species richness map through data collection and modeling techniques for wildlife habitat assessment. The GAM (Generalized Additive Model) is easy to interpret and shows better relationship between environmental variables and a response variable than an existing overlap analysis and GLM (Generalized Linear Model). The study area delineated by a large watershed contains Jirisan national park, Mt. Baekun and Sumjin river with three kinds of protected areas (a national park, a landscape ecology protected area and an otter protected area). We collected the presence-absence data for wildlife (mammals and birds) using a stratified random sampling based on a land cover in the study area and implemented natural and socio-environmental data affecting wildlife habitats. After doing a habitat use analysis and specifying significant factors for each species, we built habitat suitability models using a presence-absence model and created habitat suitability maps for each species. Biodiversity maps were generated by taxa and all species using habitat suitability maps. Significant factors affecting each species habitat were different according to their habitat selection. Although some species like a water deer or a great tit were distributed at the low elevation, most potential habitats for mammals and birds were found at the edge of a national park boundary or near a forest around the medium elevation of a mountain range. This study will be used for a basis on biodiversity assessment and proected area selection carried out by Ministry of Environment.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.4
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• pp.37-44
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• 2012

There are approximately 25,724 shelters to which people can be quickly evacuated for safety in case of emergency across the nation, and Seoul has about 3,870 shelters. Those nationwide shelters are located at a point within a five-minute radius for quick evacuation. Seoul's shelter capacity can hold 285% of its population. The problem is, however, that there is no knowing how many shelters are reachable within five minutes when considering walking speed according to individual differences in age, height, health state, and physical condition. In addition, available service areas become different according to the spatial allocation and distribution of shelters with possible vulnerable points. This study thus defined the pedestrian walking speed at 1m/s, 1.3m/s, and 2m/s by reviewing previous studies and conducted network analysis of the Location Allocation Model with the designated shelters and road networks in Seoul. The results identified the shelter service and vulnerable areas in each administrative district of Seoul according to walking speeds. It was analyzed that the vulnerable areas in which the elderly could not reach a shelter were more than twice as big as those of adult men and women with a fast walking speed.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.2
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• pp.31-40
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• 2008

The indicators of an advanced society include the overall level of life quality and satisfaction among all the members. The overall life quality has close relationships with accessibility to urban space for the social weak. Access to facilities of interest and right of mobility in urban space are very important issues to the weak class in terms of transportation including the visually handicapped. In particular, great significance is endowed upon transfer facilities, which play mediating roles between facilities like passenger facilities, and the convenience facilities inside for the disabled, which are usually the only means for the disabled to access each facility. As they are provided to the visually handicapped as well, it's very important to analyze the concerned spatial distribution and offer the results. The previous studies on the subject, however, merely covered the perceptions of the users and the related statistical analysis. This study set out to analyze non-barrier space to promote the utilization of convenience facilities at passenger facilities by the visually handicapped and to secure their right of mobility by using a GIS for spatial analysis based on spatial data. The results show that it's urgent to supplement the existing space for the handicapped and that it's necessary to expand convenience facilities for the disabled such as paths with Braille points on them to promote their use of diverse convenience facilities inside.

• Korea Journal of Hospital Management
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• v.6 no.2
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• pp.37-69
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• 2001

A new cost management system, called Activity Based Costing (ABC) system, has arisen to solve the limitation of a Traditional Cost Accounting (TCA) system until last two decades and ABC has been applied by many companies. TCA systems have limitation in tracing cost because they arbitrarily allocate overhead cost to the cost objects without standard for direct cost distribution. ABC is an accounting system that assigns costs to products or services based on the resources they consume. The costs of all activities are traced to the products for which they are performed. Therefore ABC is a cost management system that provides a matrix to accurately quantify consumed resources triggered by activities and activities triggered by products and services. There is little implementation of ABC in the health services field, one of service industries, due to complicated and many activities, and volatile cost object. However, the necessity for applying reasonable cost accounting system is largely issuing as strategy responding hostile environment, and financial pressure, and it is imperative to implement the Activity Based Costing (ABC) system. Therefore, this study presents the framework to develop ABC system for total health service organizations. Cost objects in this study base on medical service activities per health insurance claim from one general hospital located in Metropolitan Statistical Areas (MSAs). Medical service activities include all health insurance claims in the hospital. The purpose of the study is presenting useful tools and basic frame to develop Activity Based Costing system for health service organizations which want to use ABC system. The steps to develop ABC system for health service organizations are following: 1. Identifying of activity centers; 2. Definition of cost objects and activity by activity center; 3. Analysis of activity and tracing activity contribution; 4. Allocation of direct cost for specific activity; 5. Allocation of indirect cost for specific activity; 6. Allocation of depreciation for facilities, applicants, and consumption goods; 7. Allocation of administration cost; 8. Allocation of cost among activity centers; and 9. Tracing cost of cost objects by activity center. This study identified necessary information from existing reports which hospitals generally made by each step, and defined outcome which had to be produced in each step using this information. The steps of this study had limitation to apply all different size hospitals because the steps were structured ABC system by one hospital, however, this study used similar basic framework and methods with general cases. When a health service organization want to apply Activity Based Costing (ABC) system on all activities of it in future days, this study is very useful to design system structure in the health service organization.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11A
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• pp.1027-1034
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• 2005

IEEE802.15.4a, which is started to realize the PHY layer including high precision ranging/positioning and low data rate communication functions, requires a simple and low power consumable transceiver architecture. To satisfy this requirements, the simple noncoherent on-off keying (OOK) UWB transceiver with the parallel energy window banks (PEWB) giving high precision signal processing interface is proposed. The flexibility of the proposed system in multipath fading channel environments is acquired with the pulse and bit repetition method. To analyze the bit error rate (BER) performance of this proposed system, a noise model in receiver is derived with commonly used random variable distribution, chi-square. BER of $10^{-5}$ under the line-of-sight (LOS) residential channel is achieved with the integration time of 32 ns and signal to noise ratio (SNR) of 15.3 dB. For the non-line-of-sight (NLOS) outdoor channel, the integration time of 72 ns and SNR of 16.2 dB are needed. The integrated energy to total received energy (IRR) for the best BER performance is about $86\%$.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.4C
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• pp.333-341
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• 2002

This article is written to make a foundation for effective radio network engineering by enabling the accurate traffic assumption between Base Station (BTS : Base Station Transceiver Subsystem) md Repeater through the scientific and systematic analysis of mobile traffic dealt within CDMA Base Station. Among these, Repeater, having direct physical connection with BTS, simply does the remote relay function but the volume of the traffic flowed into the repeater is not accountable. The total BTS traffic is the sum of traffic dealt by the BTS and multiple Repeaters. In this article, we tried traffic analysis of this kind by adopting RTD (Round Trip Delay) which is specially designed to measure distribution of the distance between the Base Station and the Mobile station by differentiating the traffic dealt by BTS from traffic dealt by Repeaters. The fact that the connection between mobile station and BTS via Repeater (which is located remotely) yields far more delay than the direct connection between mobile station and BTS is the clue of this article. Based on this fact, Time Delay equipment was put at the receiving side of the Repeater to add certain amount of delay to the traffic to BTS and the result showed that the 99.78% of the traffic can be identified.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.5B
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• pp.475-488
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• 2003

To prevent performance degradation of TCP due to packet losses in the smooth handoff by the route optimization extension of Mobile IP protocol, a buffering of packets at a base station is needed. A buffering of packets at a base station recovers those packets dropped during handoff by forwarding buffered packets at the old base station to the mobile user. But, when the mobile user moves to a congested base station in a new foreign subnetwork, those buffered packets forwarded by the old base station are dropped and TCP transmission performance of a mobile user in the congested base station degrades due to increased congestion by those forwarded burst packets. In this paper, considering the general case that a mobile user moves to a congested base station, we analyze the influence of packet buffering on TCP performance according to handoff arrival distribution for Drop-tail and RED (Random Early Detection) buffer management schemes. Simulation results show that RED scheme can reduce the congestion increased by those forwarded burst packets comparing Drop-Tail, but RED scheme cannot avoid Global Synchronization due to forwarded burst packets by the old base station and new buffer management scheme to avoid it is needed in Mobile IP based networks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.7B
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• pp.673-685
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• 2002

In this paper, we analyze the pros and cons of the fast power control to the forward link in the environments where mixed traffics of voice and data produce the transmitted/received power difference. We propose the Zone-based power control scheme that can improve the performance of the fast power control scheme in the viewpoint of the resource allocation. The proposed scheme is a mechanism that controls both the power and rate of non-realtime data traffics according to location distribution of the mobile stations. The scheme is based on the conventional fast power control scheme in the CDMA systems, and it adaptively controls the transmission rate of each data traffic. Zone-based rate control of data call brings about somewhat power margin to the call. As a result, the proposed scheme saves the power consumption of portables and reduces the amount of interference. With the proposed scheme, not only be extended the service coverage of high-rate traffic to the entire cell service coverage, but also the QoS of low-rate traffic can keep going through the service time, especially, in the situation that the amount of incoming interference is much larger. The experimental results show that the proposed scheme yields a improved performance compared with the conventional scheme in terms of the power consumption and traffic throughput of portables, especially, with the increasing number of high-rate data traffics.

• Management & Information Systems Review
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• v.37 no.3
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• pp.65-81
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• 2018

This study estimated the long-run and the short-run price and income elasticity of crude oil demand by using the ARDL model in Korea. First, the long-run cointegration relationship existed between crude oil demand and price or income in the ARDL-bounds tests. Second, the long-run own price, the cross price elasticity and the income elasticity were both statistically significant elastic and sensitive in the ARDL. Third, there was autocorrelation of the residuals, but no misspecification errors and heteroscedasticity, and then the residuals showed a normal distribution. And the CUSUM & CUSUMSQ tests showed that the coefficients were stable. Fourth, the short-run own price, the cross price elasticity and the income elasticity were both statistically significant elastic and sensitive in the ARDL-RECM. The ECM with the short-run dynamics showed rapid adjustments in the long-run equilibrium of oil demand after the economic crisis. In the short-run, the sensitivity of crude oil demand to price and income changes has moved in the same direction as the long-run case. Korea, depending too much on foreign crude oil, is vulnerable to the shocks of oil prices, so rising oil prices can certainly have a negative impact on Korea's trade balance. And the elasticity of long-run oil prices may help to control and manage Korea's oil demand. The government needs to strengthen monitoring of the country's policies and market trends related to crude oil, establish strategies to customize national policies and market conditions, and strengthen active market dominance efforts through pioneering new market and diversification.