• Journal of the Korean Geographical Society
• /
• v.39 no.6 s.105
• /
• pp.907-921
• /
• 2004

Lots of characteristics such as dwelling, neighborhood, and accessibility characteristics affect to the housevalue. Many researches have been done to identify values of each characteristic using hedonic technique. However, there is a limit to identify interaction of each characteristic and variation of each characteristic among the accessibility context. This paper has implemented the Expansion Method research paradigm to model the housevalue determination process in the city of Seoul. The findings of this paper have revealed the presence of contextual variations in the housevalue determination process. The initial model for housevalue reveals that as $F_1$ increases (i.e., larger the number of rooms/bathrooms, larger parking space) and/or $F_2$ increases (i.e., higher owner occupied housing units, higher apartment housing units) and/or $F_3$ increases, (i.e., higher the ratio of higher than college graduated households, 8 school zone, older housing units) the estimated housevalue increases. However, the above relationships drift across their respective contexts. The houses which have negative $F_1$ value, the housevalue does not fluctuate according to the distance to the city center or subcenters. However, the houses which have positive $F_1$ value, the closer to the subcenters or shorter to the river, the higher the estimated housevalues. On the other hand, in areas far from the subcenters, the estimated housevalues does not fluctuate much according to the corresponding $F_2$ level. In areas close to the subcenters, the estimated housevalues vary tremendously according to the $F_2$ value. In the residual analysis, it is revealed that large apartment which are located in Kangnam, IchongDong, MokDong are underestimated. This paper has contributed to our understanding of the housevalue determination process by providing an alternative conceptualization to the traditional approach.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.9 no.2
• /
• pp.141-147
• /
• 2016

NHPP software reliability models for failure analysis can have, in the literature, exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, infinite failures NHPP models that repairing software failure point in time reflects the situation, was presented for comparing property. Commonly used in the field of software reliability based on Flexible Weibull extension distribution software reliability of infinite failures was presented for comparison problem. The result is that a relatively small shaping parameter was effectively. The parameters estimation using maximum likelihood estimation was conducted and model selection was performed using the mean square error and the coefficient of determination.. In this research, software developers to identify software failure property follows shape parameter, some extent be able to help is considered.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.6
• /
• pp.2237-2244
• /
• 2013

In this study, physics based K-DRUM(K-water Distributed RUnoff Model) using GIS spatial hydrologic data as input data was developed to account for the temperature variation according to the altitude change considering snow melt and cover. The model was applied for Pakistan Kunhar River Basin($2,500km^2$) to calculate long-term discharge considering snow melt and cover. Time series analysis of the temperature and rainfall data reveals that temperature and rainfall of the river basin differs significantly according to altitude change compared to domestic basin. Thus, applying temperature and altitude lapse rate during generate input data generation. As a result, calculated discharge shows good agreement with observed ones considering snow melt and accumulation characteristic which has the difference of 4,000 meter elevation above sea level. In addition, the simulated discharge strongly showed snow melting effect associated with temperature rise during the summer season.

• Journal of Korea Water Resources Association
• /
• v.32 no.3
• /
• pp.265-279
• /
• 1999

In this study, one of the techniques on the extension of low flow series has been developed, in which the daily streamflows were simulated by the Tank model with the input of extended daily rainfall series which were stochastically generated by the Markov chain model. The annual lowest flow serried for each of the given durations were formulated form the simulated daily streamflow sequences. The frequency of the estimated annual lowest flow series was analyzed. The distribution types to be used for the frequency analysis were two-parameter and three-parameter log-normal distribution, two-parameter and three-parameter Gamma distribution, three-parameter log-Gamma distribution, Gumbel distribution, and Weibull distribution, of which parameters were estimated by the moment method and the maximum likelihood method. The goodness-of-fit test for probability distribution is evaluated by the Kolmogorov-Sminrov test. The fitted distribution function for each duration series is applied to frequency analysis for developing duration-low flow-frequency curves at Yongdam Dam station. It was shown that the purposed technique in this study is available to generate the daily streamflow series with fair accuracy and useful to determine the probabilistic low flow in the watersheds having the poor historic records of low flow series.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.1 no.1
• /
• pp.83-90
• /
• 2000

DEA is a newly developed analyzing tool to measure efficiency evaluation of decision making units (DMU). It compares DMU by radial Projection on the efficient frontier. The purpose of this study is to show reference point approach used for searching solution in multiple objective linear Programming can be usefully used to determine flexible efficient frontier of each DMU In reference point approach, the minimization of ASF Produces an efficient points in frontier and enhances the usefulness of DEA by Providing flexibility in DEA and optimally allocating resources to DMU. Various DEA models can be supported by reference point method by changing the projection direction in order to choose the targets units, standards costs and management benching-marking.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2019.05a
• /
• pp.404-404
• /
• 2019

우리나라는 수자원장기종합계획과 유역종합치수계획의 수립을 통해 수자원의 개발, 안정적인 공급과 효율적인 배분, 홍수재해방지 등을 위한 많은 노력을 해왔다. 최근에는 수자원의 관리효율화, 체계적 통합적으로 시행하고자 수자원법을 제정하여 수자원 관리의 체계를 개편하였으며, 향후 지자체 중심의 정량적인 물수급평가를 통해 현실적인 결과와 대안을 마련하는 것이 필요하다. 기존의 용수공급능력 평가와 물수급계획은 시 군 중심의 용수수요량을 바탕으로 중권역 단위로 확장하고, K-WEAP(Korea-Water Evaluation And Planing System) 모형을 활용하여 용수수급전망을 제시하고 있다. 이에 본 연구에서는 한강 권역을 중심으로 기존 계획에서 활용한 K-WEAP과 국내 외 활용도가 높은 MODSIM(Modified SIMYLD)을 활용하여 각 모형에 대한 입력자료, 내부 계산 알고리즘 및 분석방법 등 모형의 적용성을 검토하여 중권역 기반의 물수급 분석 결과를 비교 하였으며, 향후 모형 적용 시 고려사항 및 발생 가능한 오류를 최소화 할 수 있도록 하고자 하였다. 분석 결과, 기존 수자원장기종합계획에서 활용한 K-WEAP모형은 생 공 농업용수가 모두 동일우선순위이나, MODSIM모형에서는 수요지별 우선순위를 고려해야 하므로 상 하류간, 생활 공업, 농업으로 우선순위를 부여할 경우 물 부족량의 차이가 발생하였다. 우선순위 적용시 K-WEAP과 형과 MODSIM을 비교할 경우, 유사한 물부족량과 시점을 제공하고 있어 적용성과 분석결과의 일관성을 확인할 수 있었다. 또한 같은 물부족 결과를 제공하는 조건의 검토 수행 시간 측면과 모형구동 결과의 안정성에서 MODSIM이 더 우수한 것으로 분석되어 향후 지자체 중심의 세부적인 물수급평가를 위해서는 빠른 의사결정을 도울 수 있을 것으로 판단된다.

• Annual Conference of KIPS
• /
• 2009.04a
• /
• pp.663-665
• /
• 2009

Ubi-Home 환경에서 장치제어를 하기위해 다양한 방법이 제안되었다. 그 중 원격지에서 장치제어를 하기 위해 특정 기기(로봇)를 활용할 수 있다. 하지만 이와 같은 방법에는 로봇과 장치들의 위치인식과 이동경로 설정에 따른 제약사항이 따른다. 또한 이러한 위치인식 및 이동에는 미리 작성된 하나의 맵이 사용되므로 새로운 환경의 변화나 확장에 적용할 수 없다. 따라서 본 논문에서는 로봇과 장비의 위치인식과 이동경로를 위한 학습형 맵 작성 기법을 제안하며, 테스트를 위해 Atmega128v4 MCU와 AX-12+ Motor, AX-S1 Sensor, ZBS-200 Zigbee, CL-1L5/603LM Infrared Ray Sensor로 로봇을 제작하여 실내 환경 모형에서 테스트하였다.

• Journal of Korea Water Resources Association
• /
• v.50 no.6
• /
• pp.359-371
• /
• 2017

This study generated flood time series of ungauged catchments in the Andongdam catchment using a distributed rainfall-runoff model and data generation method, and extracted the peak flows of 50 catchments to investigate the effect of rainfall spatial variability on peak flow simulation. The model performance statistics for three gauged catchments were reasonable for all events. The flood time series of the 50 catchments were generated using distributed and mean rainfall time series as input. The distribution of the peak flow using the mean rainfall was similar or slightly different to that using the distributed rainfall when the distribution of the distributed rainfall was nearly uniform. However, the distribution of the peak flow using the mean rainfall was reduced significantly compared to that using the distributed rainfall when actual storms moved to the top or bottom of the study catchment, or the rainfall was randomly distributed. These cases were 35% of total number events. Therefore, the spatial variability of rainfall should be considered for flood simulation. In addition, the power law relationship estimated using the peak flow of gauged catchments cannot be used for estimating the peak flow of ungauged independent catchments due to latter's significant variation of the peak flow magnitude.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.11 no.4
• /
• pp.91-102
• /
• 1991

Traditionally, a dynamic programming(DP) technique has been used to the multireservoir control system. The algorithm has inherent problem to increase computational requirements exponentially due to discretization of variables and expanding the dimension of the system. To solve this problem, this paper describes transforming the optimal control system into a quadratic programming(QP), using Laguerre polynomials(LP) and its properties. The objective function of the proposed QP is independent of time variable. The solution of the QP is obtained by nonlinear programming(NLP) using augmented Lagrangian multiplier method. The numerical experiment shows that the water level of reservoirs is higher than Lee's and the evaluated benefit value is about the same as other researcher's.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.12
• /
• pp.3447-3455
• /
• 1999

Database correctness is guaranteed by standard transaction scheduling schemes like two-phase locking for the context of concurrent execution environment in which short-lived ones are normally mixed with long-lived ones. Traditional syntax-oriented serializability notions are considered to be not enough to handle in particular various types of transaction in terms of duration of execution. To deal with this situation, altruistic locking has attempted to reduce delay effect associated with lock release moment by use of the idea of donation. An improved form of altruism has also been deployed in extended altruistic locking in a way that scope of data to be early released is enlarged to include even data initially not intended to be donated. In this paper, we first of all investigated limitations inherent in both altruistic schemes from the perspective of alleviating starvation occasions for transactions in particular of short-lived nature. The idea of two-way donation locking(2DL) has then been experimented to see the effect of more than single donation in distributed database systems. Simulation experiments shows that 2DL outperforms the conventional two-phase locking in terms of the degree of concurrency and average transaction waiting time under the circumstances that the size of long-transaction is in between 5 and 9.