• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
• /
• 2010.06a
• /
• pp.185-185
• /
• 2010

문명 발전에 의해 생활공간이 더욱더 복잡해짐에 따라 현실 세계의 3차원 공간으로서의 이해가 필요해졌고, 3차원 공간을 효율적으로 관리 및 분석하기 위하여 3차원 GIS에 대한 중요성이 대두되기 시작하였다. 현재까지의 3차원 GIS는 1990년대에 들어서 3차원 가상도시의 등장으로 도시 모델의 3차원 가시화에 대해 많은 연구가 진행되어 왔다. 이러한 3차원 가상도시는 도시 관리 차원에서 도시공간의 표현, 분석, 모델링, 시뮬레이션 등을 통하여 도시정보의 체계적이고 효율적인 관리를 가능하게 한다. 3D GIS 기술의 활용 사례로는 3차원 도시 경관 분석 및 도시 계획, 3차원 시뮬레이션, 3차원 위치기반 서비스, 도시 행정 관리 등이 있다. 3차원 도시 경관 분석 및 도시 계획 활용 분야에서는 3차원 GIS를 활용하여 새롭게 건설되는 건물들이나 토지 이용 변경에 따른 경관 분석을 가상공간에서 시뮬레이션 분석함으로써 경관 변화 예측 및 적합한 경관 설계에 대한 분석을 한다. 3차원 시뮬레이션의 경우 환경오염도 분석, 최적의 입지선정, 개발 전후의 경관 차이, 각종 재난에 따른 위험도 분석, 경관과 일조량 분석 등을 미리 가상도시에 시뮬레이션 함으로서 불필요한 업무를 줄일 수 있고 발생할 수 있는 결과 값을 예상할 수 있다. 3차원 위치기반 서비스의 경우 자신의 위치를 비교적 정확히 측정함으로서 생소한 도시를 방문하거나 위치를 찾아갈 경우 최단 경로 및 최적 경로를 탐색할 수 있다. 앞으로의 3차원 GIS 기술 동향으로 유비쿼터스 환경에서의 시공간분석(Temporal GIS)과 3차원 실내공간인지 기술 개발 등으로 볼수있다. 시공간분석은 시공간 질의를 통한 공간정보의 시간에 다른 변화 계산 또는 예측된 결과를 분석할 수 있고, 시공간 분석에 사용되는 공간적, 시간적 정보의 조합은 적어도 3차원 이상의 정보를 나타내기 때문에 필요에 따라 다양한 결과를 산출 할 수 있다. 종합적으로 시공간분석은 GIS의 분석 범위를 넓혀 주며 실시간 GIS 응용시스템 개발을 위한 주요 과업이다. 3차원 실내공간정보 표현기법과 공간분석 및 공간인지 기법을 이용한 통한 유비쿼터스 환경에서의 3차원 실내공간인지 기술 개발을 통해 최근 공간정보를 기반으로 한 위치기반서비스내 u-서비스 즉, 인간 행태의 분석, 관리 및 응용을 지원하도록 한다 이는 위치기반서비스 사용자의 주변상황에 대한 인지능력을 향상시켜주고 최근 사회적 이슈가 되고 있는 U-City의 성공여부에 직접적인 영향을 미칠것이다. 이를 위해 다음과 같은 기술개발이 수행되어야 할것이다. 첫째로, 공간인지 기술을 위한 3차원 실내공간표현 방법 개발, 둘째로, 3차원 실내공간정보를 이용한 공간분석 및 공간인지 기법 개발, 마지막으로 유비쿼터스 환경에서 3차원 실내공간인지를 위한 미들웨어 개발을 통해서 공간정보의 활용을 macro-scale 공간에서 micro-scale로 확산될 것이다. 그러므로, 본 세미나를 통해서, 3차원 GIS의 활용의 보편화와 대중화를 위해서는 3차원 데이터 획득 및 처리 방법, 3차원 공간데이타베이스, 공간 분석 및 가시화에 대한 기술적 이슈들을 논하고자 한다.

• Spatial Information Research
• /
• v.22 no.1
• /
• pp.9-17
• /
• 2014

This study was intended to reliably predict the traffic green house gas emission in Daegu with the use of spatial statistical technique and calculate the traffic green house gas emission of each administrative district on the basis of the accurately predicted emission. First, with the use of the traffic actually surveyed at a traffic observation point, and traffic green house gas emission was calculated. Secondly, on the basis of the calculation, and with the use of Universal Kriging technique, this researcher set a suitable variogram modeling to accurately and reliably predict the green house gas emission at non-observation point suitable through spatial correlation, and then performed cross validation to prove the validity of the proper variogram modeling and Kriging technique. Thirdly, with the use of the validated kriging technique, traffic green gas emission was visualized, and its distribution features were analyzed to predict and calculate the traffic green house gas emission of each administrative district. As a result, regarding the traffic green house gas emission of each administration, it was found that Bukgu had the highest green house gas emission of $291,878,020kgCO_2eq/yr$.

• Journal of Korean Society of Transportation
• /
• v.25 no.2 s.95
• /
• pp.17-26
• /
• 2007

Because the prime objective of the current preemption methods at signalized intersections near highway-railroad grade crossings(IHRGCs) is to clear the crossing, secondary objectives such as safe pedestrian crossing time and minimized delay often are given less consideration or are ignored completely during the preemption. Under certain circumstances state-of-the-practice traffic signal preemption strategies may cause serious pedestrian safety and efficiency problems at IHRGCs. An improved transition preemption strategy(ITPS) that is specifically designed to improve intersection performance while maintaining or improving the current level of safety was developed by Cho and Rilett. Even if the new transition preemption strategy improved both the safety and efficiency of IHRGCs, the performance of the strategy is affected by train speed. Understanding the impact of this factor is essential in order to implement ITPS. In this paper, the effects of train speed were analyzed using a VISSIM simulation model which was calibrated to field conditions. It was concluded that the delay is affected more by train speed than the transitional preemption strategy and the safety of the intersection is not affected by train speed once an advanced preemption warning time(APWT) is equal to or greater than 90 seconds.

• Journal of the Korean Geotechnical Society
• /
• v.31 no.6
• /
• pp.59-69
• /
• 2015

Recently, landslide and debris-flow disasters caused by severe rain storms have frequently occurred. Many researches related to landslide susceptibility analysis and debris-flow hazard analysis have been conducted, but there are not many researches related to mobilization analysis for landslides transforming into debris-flow in slope areas. In this study, statistical analyses such as discriminant analysis and logistic regression analysis were conducted to develop a mobilization criterion using geomorphological and geological factors. Ten parameters of geomorphological and geological factors were used as independent variables, and 466 cases (228 non-mobilization cases and 238 mobilization cases) were investigated for the statistical analyses. First of all, Fisher's discriminant function was used for the mobilization criterion. It showed 91.6 percent in the accuracy of actual mobilization cases, but homogeneity condition of variance and covariance between non-mobilization and mobilization groups was not satisfied, and independent variables did not follow normal distribution, either. Second, binomial logistic analysis was conducted for the mobilization criterion. The result showed 92.3 percent in the accuracy of actual mobilization cases, and all assumptions for the logistic analysis were satisfied. Therefore, it can be concluded that the mobilization criterion for debris-flow using binomial logistic regression analysis can be effectively applied for the prediction of debris-flow hazard analysis.

• Journal of the Korean Geographical Society
• /
• v.31 no.4
• /
• pp.648-661
• /
• 1996

The traditional von Thunen model has various shortcomings. Perhaps the greatest dificiency is the model's sole emphasis on the production side of the economy;that is, the agricultural markets are rarely closed for demand. In thes paoer a closed model for a three-activity, two-dimensional economy is developed. Equillibrium solutions are generated for prices, land areas, and outputs. Comparative static analysis then follows. Attention is next given to a maximum expected-return model under environmental uncertainty. Land uses for the traditional model and the closed model are then compared.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.18 no.10
• /
• pp.1422-1432
• /
• 1993

Nonlinear mapping function of the HCNN( Hidden Control Neural Network ) can change over time to model the temporal variability of a speech signal by combining the nonlinear prediction of conventional neural networks with the segmentation capability of HMM. We have two things in this paper. first, we showed that the performance of the HCNN is better than that of HMM. Second, the HCNN with its prediction error measure given by weighted distance is proposed to use suitable distance measure for the HCNN, and then we showed that the superiority of the proposed system for speaker-independent speech recognition tasks. Weighted distance considers the differences between the variances of each component of the feature vector extraced from the speech data. Speaker-independent Korean digit recognition experiment showed that the recognition rate of 95%was obtained for the HCNN with Euclidean distance. This result is 1.28% higher than HMM, and shows that the HCNN which models the dynamical system is superior to HMM which is based on the statistical restrictions. And we obtained 97.35% for the HCNN with weighted distance, which is 2.35% better than the HCNN with Euclidean distance. The reason why the HCNN with weighted distance shows better performance is as follows : it reduces the variations of the recognition error rate over different speakers by increasing the recognition rate for the speakers who have many misclassified utterances. So we can conclude that the HCNN with weighted distance is more suit-able for speaker-independent speech recognition tasks.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.05a
• /
• pp.317-321
• /
• 2022

In response to Incheon tap water accident in 2019, the Ministry of Environment has created the "Comprehensive Measures for Water Safety Management" to improve water operation management, provide systematic technical support, and respond to accidents. Accordingly, K-water is making a smart water supply management system for the entire process of tap water. In order to advance the response to water accidents, it is essential to secure the reliability of real-time water operation data such as flow rate, pressure, and water level, and to develop and apply a warning algorithm in advance using big data analysis techniques. In this paper, various statistical techniques are applied using water supply operation data (flow, pressure, water level, etc) to prepare the foundation for the selection of the optimal operating range and advancement of the monitoring and alarm system. In addition, the arrival time is analyzed through cross-correlation analysis of changes in raw water turbidity between the water intake and water treatment plants. The purpose of this paper is to study the model that predicts the raw water turbidity of a water treatment plant by applying raw water turbidity data considering the time delay according to the flow rate change.

• Journal of the Korean Geotechnical Society
• /
• v.26 no.1
• /
• pp.45-54
• /
• 2010

It is important to calculate the natural frequency of a piled structure in the design stage in order to prevent resonance-induced damage to the pile foundation and analyze the dynamic behavior of the piled structure during an earthquake. In this paper, a simple but relatively accurate method employing a mass-spring model is presented for the evaluation of the natural frequency of a pile-soil system. Greatly influencing the calculation of the natural frequency of a piled structure, the spring stiffness between a pile and soil was evaluated by using the coefficient of subgrade reaction, the p-y curve, and the subsoil elastic modulus. The resulting natural frequencies were compared with those of 1-g shaking table tests. The comparison showed that the natural frequency of the pile-soil system could be most accurately calculated by constructing a stiffness matrix with the spring stiffness of the Reese (1974) method, which utilizes the coefficient of the subgrade reaction modulus, and Yang's (2009) dynamic p-y backbone curve method. The calculated natural frequencies were within 5% error compared with those of the shaking table tests for the pile system in dry dense sand deposits and 5% to 40% error for the pile system in saturated sand deposits depending on the occurrence of excess pore water pressure in the soil.

• The Journal of the Acoustical Society of Korea
• /
• v.42 no.3
• /
• pp.250-261
• /
• 2023

In this study, the noise contributions by the duct, stator and rotor, which are the propulsor components, are evaluated to identify the flow noise source in cavitation and non-cavitation conditions on pumpjet propulsion and the noise levels in both conditions are compared. The unsteady incompressible Reynolds averaged Navier-Stokes (RANS) equation based on the homogeneous mixture assumption is applied on the suboff submarine hull and pumpjet propeller in the cavitation tunnel, and the Volume of Fluid (VOF) method and Schnerr-Sauer cavitation model are used to describe the two-phase flow. Based on the flow simulation results, the acoustic analogy formulated by Ffowcs Williams and Hawkings (FW-H) equation is applied to predict the underwater radiated noise. The noise contributions are evaluated by using the three types of impermeable integral surface on the duct, stator and rotor, and the two types of permeable integral surface surrounding the propulsor. As a result of noise prediction, the contribution by the stator is insignificant, but it affects the generation of flow noise source due to flow separation in the duct and rotor, and the noise is predominantly radiated into the upward and right where the flow separations are. Also, the noise is radiated into the thrust direction due to pressure fluctuation between suction and pressure sides on the rotor blades, and the it can be seen that the cavitation effect into the noise can be considered through the permeable integral surface.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2021.06a
• /
• pp.43-43
• /
• 2021

Sesan강과 Srepok강은 베트남, 캄보디아, 라오스가 공유하는 3S강 유역 (Sesan강, Srepok강, Sekong강)의 일부로 국제 공유하천으로 관리되고 있다. 3S강 유역은 Mekong강의 중요한 지류이며 Mekong강 유역의 상당 부분을 구성한다(Mekong강 유역 면적의 10%, 연간 총 유출량의 20%). 베트남에 속해 있는 Sesan강 유역면적은 11,255km², Srepok강 유역면적은 18,162km²이다. Sesan강과 Srepok강의 상류는 베트남 중부 고원의 긴 산맥에 위치하고 있으며, 하류는 캄보디아에 위치해 있어 상·하류간 긴밀한 협력이 필요하다. Sesan강과 Srepok강 유역은 기후변화에 따른 홍수, 가뭄, 수력발전소 건설로 인한 유출량 변동에 따른 상·하류 분쟁, 사면침식 및 퇴적 등 많은 문제와 도전에 직면할 것으로 예측되고 있다. 본 연구에서는 World Bank의 "Viet Nam Mekong Integrated Water Resources Management (M-IWRM) Project의 일환으로 베트남 정부 차원에서 처음으로 구축한 수자원관리 의사결정지원시스템인 "DSS-2S"를 활용하여, Sesan-Srepok강 유역의 수자원 계획을 수립하였다. DSS-2S는 MIKE Hydro Basin을 기반으로 SWAT모델 등과 연계 하여 구축되었다. DSS-2S는 2S 유역의 모든 주요 하천과 지류를 반영하였으며. 여기에는 17개의 수력발전 댐과 주요 지류에서 용량이 3백만 m³ 이상인 기타 저수지가 포함되었다. 이 보다 작은 용량의 저수지는 대표적인 저수지로 그룹화 되어 반영되었다. 기후변화 및 사회-경제적 발전계획 등을 반영하여, 2030년과 2050년을 목표연도로 생활, 공업, 농업, 관광, 유지용수 등 용수 수요를 추정하였다. 50% 및 85% 빈도의 공급 가능성을 고려하여 물 배분은 물 수요를 충족하고 지하수 개발 최소화를 기준으로 고려되었다. 분석 결과에 의하면 2S강 유역의 총 수자원은 32.2억 m³으로 그중 지표수자원은 29.2억 m³, 안정적으로 이용 가능한 지하수자원은 2.97억 m³으로 분석 되었으며, 지표수와 지하수 연계를 고려하면 전체 2S 강 유역에 물 부족하지는 않으나, 개별 공급 지점을 고려할 때 4월과 5월에 일부 지역에서 물 부족이 나타날 것으로 예측 된다. 장래 물 부족 해결을 위한 대안들을 제시하였으며, 본 성과는 베트남 중앙 정부의 장기수자원 종합계획 수립의 기본 자료로 활용 될 예정이다.