• The Journal of Information Technology
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• v.5 no.1
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• pp.13-28
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• 2002

This study examines the relationships between the adoption intention and ill results/"digital divide" of informatization. It is very important to enhance the ability to use the information around the country today. Government invested large sums in informatization. As a result, we became a leading country in the information and communication technologies (ICTs). But the speedy growth in information society enlarges the gab between 'information haves'and 'information have-nots', which results in decreasing the efficiency of informatization. Now, we have to consider the idea of "information welfare policy" to approach the problems of "information poor"which refers to those deprived of opportunities to access ICTS and use of the Internet. This paper shows that we can not reach the information welfare society without the solution of these problems, and which are obstacles to progress in informatization. It is hoped that the results from this study bridge and close so called "Digital Divide" within society and create the impartial information welfare society.e impartial information welfare society.

• Journal of computational fluids engineering
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• v.22 no.1
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• pp.37-42
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• 2017

Infrared signals are frequently used to detect objects exposed to wide variety of environmental conditions. Detection by infrared signature is accomplished by distinguishing objects by using the IR radiant contrast between objects and the background. There are several methods of estimating the IR radiant contrast. The inverse distance weighting method, which is one of the IR radiant contrast estimation method using the effect of distance from objects, is known to be an effective way to analyze radiant contrast for complex backgrounds. However this method has a disadvantage of requiring a long calculation time. In this study we propose a statistical method of estimating the IR radiant contrast by using randomly selected pixels of arbitrary number among background pixels to reduce calculation time. Some measured IR images in MWIR and LWIR regions are used to test the applicability of the method proposed and we found that the proposed method is very effective in determining the IR radiant contrast showing very rapid estimation with minar accuracy loss.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.162-167
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• 2007

수질오염총량관리제에서 단위유역 할당부하량은 지자체의 개발용량과 밀접한 관계를 가지고 있기 때문에 상 하류 지역간의 첨예한 관심거리가 되고 있다. 총량관리제는 기준유량과 목표수질에 대한 기준배출부하량의 달성을 목적으로 하고 있기 때문에 합리적이고 과학적인 기준유량 및 목표수질의 설정이 무엇보다 중요하다. 또한 합리적인 수질모델링을 필요로 하는데, 유량배분은 모델링 과정에서 중요한 영향을 미치며, 지역의 기준배출부하량을 결정하는 결정적인 요소 중의 하나이다. 기존의 유량배분은 대부분 관측지점을 기준으로 한 단순한 면적비 유량배분기법(SAWA; simple area-based water-balance analysis)에 의존해왔다. 그러나 SAWA는 특정유역의 토지피복, 토양, 지형경사 및 강우분포 등의 수문학적 특성을 고려하지 못하는 한계점을 가지고 있다. 즉, 동일한 면적의 유역이라도 이러한 수문 특성인자에 따라 유출되는 유량이 달라지는 현상을 고려하지 못하고 있다. 이는 곧 지역의 기준배출부하량의 신뢰성에 영향을 미치기 때문에 지역간 분쟁의 소지가 될 수 있다. 본 연구는 기존의 유량배분 방법인 SAWA가 가지는 한계점을 극복하고자 강우분포 및 토지피복의 수문학적 특성을 이용한 유량배분기법(HIWA; hydro-infomatical water-balance analysis)의 개발을 목적으로 수행되었다. 강우분포와 토지피복이 하천유량에 미치는 영향을 분석하고 공간정보화 한 후 지형정보체계(GIS)의 수문분석 기법을 이용하여 유량을 배분하였다 ARC/INFO의 KRIGING 보간법을 이용하여 구축한 등강우분포도와 토지피복에 따른 유출특성을 분석하여 강우유출 해석을 위한 가중지형정보를 생성하였다. 연구는 2003년 10월-2004년 3월의 미호천수계 및 수질오염총량관리단위유역 말단지점의 실측자료를 이용하였으며, 연구결과 기존의 SAWA보다 본 연구에서 제안한 HIWA가 유량배분의 정확도를 높일 수 있음이 입증되었다.

• The Journal of Engineering Geology
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• v.8 no.3
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• pp.235-245
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• 1998

Adquate friction resistance is needed to prevent pavement slipperiness and to allow vehicles to stop in a reasonable distance. Performance of the aggregates is reduced over time by wear and polishing as a consequence of vehicular traffic. In this research, the objective was to develop a laboratory method to test Indiana gravel aggregates to predict field performance, and determine causes for the range of values amang gravel aggregates. The assessment of gravel sources was primarily on the basis of individual rock types and those proportions comprising the gravel. Polish and friction values were determined in the laboratory with the British Wheel and Pendulum. The gravels of this study were composed primarily of carbonate aggregates that showed considerable variability in polishing thresholds. Igneous and metamorphic constituents polished to a lesser degree and are expected to improve overall aggregate performance. Estimates of the IFV (Initial Friction Value) and PV (Polished Value) for crushed gravel samples can be made based on the percentage of rock types present in the sample. A weighted average is used to make this calculation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.1947-1953
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• 2012

The vehicle fuel economy is very important issue in the view of global warming. This paper proposes the three fuel economy improvement algorithms which predict the velocity using altitude data of the positions in front of vehicle and estimates their performances. The proposed 3 algorithms are WMGA(Weighted Mean Gradient Angle), RAADE I, II(Reacceleration After Deacceleration I, II). This research extracts the distance and altitude data from received GPS data and calculates gradient angle and road load for each section. The velocity profile according to proposed algorithms is made for Youngdong highway of 213km. And the test vehicle runs along this highway and fuel economy is measured. RAADE II of proposed algorithms showed better performance by 3.571% in comparison to the conventional CVELCONT3.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.9B
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• pp.947-954
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• 2009

In mobile ad hoc networks, service discovery to search for an available service is an important issue. In this paper, we propose an efficient service discovery protocol that is combined a dht-based service discovery scheme and a P2P caching-based information spreading scheme. Proposed scheme store key information in hashed zone and search services using it's information. To search quickly a service, it use its physical neighbors information which collected by 1-hop hello message between a node and its physical neighbors. We do not use a central look up server and do not rely on flooding. Hence, it uniquely balanced all node's load in mobile ad hoc networks and reduced the number of messages exchanged, network load and response time. The simulation results show that our protocol outperforms DHT-based and flooding protocols.

• Journal of Korea Water Resources Association
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• v.50 no.12
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• pp.849-862
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• 2017

The increased frequency of meteorological disasters has been observed due to increased extreme events such as heavy rainfalls and flash floods. Numerous studies using high-resolution weather radar rainfall data have been carried out on the hydrological effects. In this study, a conditional merging technique is employed, which makes use of geostatistical methods to extract the optimal information from the observed data. In this context, three different techniques such as kriging, inverse distance weighting and spline interpolation methods are applied to conditionally merge radar and ground rainfall data. The results show that the estimated rainfall not only reproduce the spatial pattern of sub-hourly rainfall with a relatively small error, but also provide reliable temporal estimates of radar rainfall. The proposed modeling framework provides feasibility of using conditionally merged rainfall estimation at high spatio-temporal resolution in ungauged areas.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.4
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• pp.29-38
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• 2013

This study is to construe the spatio-temporal characteristics of temperature in cities and the changes of climatical regions by analyzing a climate change in Korea peninsular. We used daily mean air temperature data which were collected in South and North climate stations for the past 34 years from 1974 to 2007. We created temperature maps of 500m resolution with Inverse Distance Weight in application with adiabatic lapse rate per month in linear relation with height and temperature. In the urbanization area, the data analyzed population in comparison with temperature changes by the year. The south climate region in Korea by the Warmth index was expanded to the middle climate region by the latitude after 1990s. A rise of mean temperature was $0.5{\sim}1.2^{\circ}C$ in urban areas such as Seoul, metropolitan and cities which had a rapid urbanization and industrialization with the population increase between 1980s and 1990s. In case of North Korea, cities such as Pyeongyang, Anju, Gaecheon, and Hesan had the same pattern.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.218-219
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• 2011

This paper focuses on dispatching strategy for AGVs(Automated Guided Vehicle). The goal of AGV dispatching problem is allocating jobs to AGVs to minimizing QC delay and AGV total travel distance. Due to the highly dynamic nature of container terminal environment, the effect of dispatching is hard to predict thus it leads to frequent modification of dispatching results. Given this situation, single rule-based approach is widely used due to its simplicity and small computational cost. However, single rule-based approach has a limitation that cannot guarantee a satisfactory performance for the various performance measures. In this paper, dispatching strategy based on multicriteria heuristics is proposed. Proposed strategy consists of multiple decision criteria. A muti-objective evolutionary algorithm is applied to optimize weights of those criteria. The result of simulation experiment shows that the proposed approach outperforms single rule-based dispatching approaches.

• Journal of the Korean Geographical Society
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• v.46 no.2
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• pp.197-211
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• 2011

Due to the complexity of spatial interaction and the necessity of spatial representation and modeling, aggregation of spatial interaction data is indispensible. Given this, the purpose of this paper is to evaluate the effects of modifiable areal unit problem (MAUP) on a spatial interaction model. Four aggregation schemes are utilized at eight different scales: 1) randomly select seeds of district and then allocate basic spatial units to them, 2) minimize the sum of population weighted distance within a district, 3) maximize the proportion of flow within a district, and 4) minimize the proportion of flow within a district. A simple Poisson regression model with origin and destination constraints is utilized. Analysis results demonstrate that spatial characteristics of residuals, parameter values, and goodness-of-fit of the model were influenced by aggregation scale and schemes. Overall, the model responded more sensitively to aggregation scale than aggregation schemes and the scale effect on the model was varied according to aggregation schemes.