• Tunnel and Underground Space
• /
• v.23 no.5
• /
• pp.353-361
• /
• 2013

Previous studies for analyzing optimal haulage routes of dump trucks in open pit mines mostly used raster data. However, the raster data has several problems in performing optimal route analyses: (1) the jagged appearance of haulage roads according the cell resolution often causes overestimation of the travel cost; (2) it difficult to trace the topological relationships among haulage roads. These problems can be eliminated by using vector network data, however a new method is required to reflect the performance characteristics of a dump truck according to terrain gradient changes. This study presents a new method to create vector network data with the consideration of terrain gradient for analyzing optimal haulage routes of dump trucks in open pit mines. It consists of four procedures: (a) creating digital elevation models, (b) digitizing haulage road networks, (c) calculating the terrain gradient of haulage roads, and (d) calculating the average speed and travel time of a dump truck along haulage roads. A simple case study at the Roto South pit in the Pasir open pit coal mine, Indonesia is also presented to provide proof that the proposed method is easily compatible to ArcGIS Network Analyst software and is effective in finding optimal haulage routes of dump trucks with considering terrain gradient in open pit mines.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.35 no.1
• /
• pp.165-172
• /
• 2015

The appropriateness of railway route design is generally evaluated by the future value corresponding to the travel demand or benefit-cost analysis. These methods may have the limitation for the reasons that all the design alternatives cannot be considered, and the differentiation between the alternatives may not be significant because the alternatives are based on the strict basic scheme such as the design criteria. In addition, the cost varies by the design elements. In this study, all the design alternatives are considered with the automatized tool and the design criteria, and evaluated with the multi-criterion decision making method. The weight for each design element with the analytic hierarchical process may be helpful to derive more efficient railway alignment.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.9 no.1
• /
• pp.221-227
• /
• 2008

A vehicle routing problem with time constraint is one of the important problems in distribution and transportation. The service of a customer must start and finish within a given time interval. Our method is based on an improved operators of genetic algorithm and the objective is to minimize the cost of servicing the set of customers without being tardy or exceeding the capacity or travel time of the vehicles. This research shows that a proposed method based on the improved genetic search can obtain good solutions to vehicle routing problems with time constrained compared with a high degree of efficiency other heuristics. For the computational purpose, we developed a GUI-type computer program according to the proposed method and the computational results show that the proposed method is very effective on a set of standard test problems, and can be potentially useful in solving the vehicle routing problems.

• Journal of Korean Society of Transportation
• /
• v.24 no.5 s.91
• /
• pp.77-88
• /
• 2006

The purpose of this study is to Propose the time dependent K-least time path algorithm applicable to a real-time based operation strategy in multi-modal transportation network. For this purpose, we developed the extended method based on entire path deletion method which was used in the static K-least time path algorithm. This method was applied to time dependent K-least time path algorithm to find k least time paths in order based on both time dependant mode-link travel time and transfer cost In particular, this algorithm find the optimal solution, easily describing transfer behavior, such as walking and waiting for transfer by applying a link-based time dependent label. Finally, we examined the verification and application of the Proposed algorithm through case study.

• Journal of Digital Convergence
• /
• v.8 no.3
• /
• pp.19-37
• /
• 2010

One of the core issues in the realization of e-government is the effective implementation of a website. The current trend of e-government is developing individual web sites and portals, covering such fields as education, tax, economics, real estate, travel, and health. Evaluating e-government web sites is essential for improving web sites. These principles can be included in usability in a broader concept. Website usability has attracted considerable research on website evaluation and has been regarded as one of the most important criteria for measuring and evaluating websites. Usable e-government web sites make citizens willing to search for helpful information or solve their civil applications. The objective of this paper is to suggest an Analytic Hierarchy Process (AHP) method for evaluating e-government web sites. The proposed AHP method has two special characteristics compared to general AHP approaches. First, all citizens who are e-government users can evaluate both the usability criteria and the web sites, but the weighting mechanism differs between criteria and web sites. Secondly, a pairwise comparison is time-consuming and not cost effective with many criteria. Therefore for evaluating a website with respect to a sub-criterion, we develop checklist items as measure scales with a seven-point rating. This method is efficient as it enable us to avoid the pairwise comparison mechanism between sub-criteria. A new computation procedure for the AHP is developed that combines and synthesizes priorities of portals in the case that two decision maker groups are involved.

• Journal of Korean Society of Transportation
• /
• v.31 no.5
• /
• pp.48-59
• /
• 2013

Normally the benefits concerned in the feasibility study for highway constructions are travel time saving, vehicle operation cost, etc. which can be calculated using the simulation tool(EMME3). However, there must be extra benefits of driving amenity improvement that drivers can perceive through decreasing driving fatigue and improving driving comfortability. In this study, the definition of driving amenity was established and a method of estimation for the benefit of driving amenity improvement was developed. Highway type (urban/rural highway) and highway density was considered to estimate the driving amenity. And Double-bounded Dichotomous Choice among Contingent Valuation Method(CVM) was applied to survey the willingness-to-pay of drivers when highway density decreases. Finally the value of driving amenity was estimated using the results of survey and logit medel. As the existing highway density is high, willingness-to-pay increases in both urban and rural highways. Even though the changing rates of highway density are same, willingness-to-pay is different based on the existing highway density.

• Journal of Positioning, Navigation, and Timing
• /
• v.12 no.2
• /
• pp.91-100
• /
• 2023

The existing indoor localization method using Wi-Fi fingerprinting has a high collection cost and relatively low accuracy, thus requiring integrated correction of convergence with other technologies. This paper proposes a new method that significantly reduces collection costs compared to existing methods using Wi-Fi fingerprinting. Furthermore, it does not require labeling of data at collection and can estimate pedestrian travel paths even in large indoor spaces. The proposed pedestrian movement path estimation process is as follows. Data collection is accomplished by setting up a feature area near an indoor space intersection, moving through the set feature areas, and then collecting data without labels. The collected data are processed using Kernel Linear Discriminant Analysis (KLDA) and the valley point of the Euclidean distance value between two data is obtained within the feature space of the data. We build learning data by labeling data corresponding to valley points and some nearby data by feature area numbers, and labeling data between valley points and other valley points as path data between each corresponding feature area. Finally, for testing, data are collected randomly through indoor space, KLDA is applied as previous data to build test data, the K-Nearest Neighbor (K-NN) algorithm is applied, and the path of movement of test data is estimated by applying a correction algorithm to estimate only routes that can be reached from the most recently estimated location. The estimation results verified the accuracy by comparing the true paths in indoor space with those estimated by the proposed method and achieved approximately 90.8% and 81.4% accuracy in two experimental spaces, respectively.

• Journal of Korean Society of Forest Science
• /
• v.88 no.3
• /
• pp.400-407
• /
• 1999

The purpose of thin paper is to test difference of the two question formats, open-ended and dichotomous choice formats, in the contingent valuation method using the estimated recreational benefits. The data were collected from the visitors at the Songnisan National Park. The recreational benefit based on the equivalent variation. The two question formats, but the same content, were asked of the same individuals. In this analysis, it was used travel cost and monthly income as the exogenous variables, which assumed a linear functional form for the WTP equation. The model assumed a bivariate normal distribution on the basis of the probit and tobit model concerning the censored zero WTP. The result showed no differences in the recreational benefits from the different question formats under a same respondent. The mean benefit was estimated 25.556 Won per 5 years per visitors.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.5 no.3
• /
• pp.27-45
• /
• 2010

It is strongly believed that multicast will become one of the most promising services on internet for the next generation. Multicast service can be deployed either on network-layer or application-layer. IP multicast (network-layer multicast) is implemented by network nodes (i.e., routers) and avoids multiple copies of the same datagram on the same link. Despite the conceptual simplicity of IP multicast and its obvious benefits, it has not been widely deployed since there remain many unresolved issues. As an alternative to IP multicast, overlay multicast (application-layer multicast) implements the multicast functionality at end hosts rather than routers. This may require more overall bandwidth than IP multicast because duplicate packets travel the same physical links multiple times, but it provides an inexpensive, deployable method of providing point-to-multipoint group communication. In this paper we develop an efficient method applied greedy algorithm for solving two models of overlay multicast routing protocol that is aimed to construct MDST (Minimum Diameter Spanning Tree : minimum cost path from a source node to all its receivers) and MST (Minimum Spanning Tree : minimum total cost spanning all the members). We also simulate and analyze MDST and MST.

• Journal of Korean Society of Transportation
• /
• v.23 no.3 s.81
• /
• pp.7-19
• /
• 2005

Mode choice Analysis is essential analysis stage in transportation demand forecasting process. Therefore, methods for calibration and forecasting of mode choice model in aspect of practical view need to be discussed in depth. Since 1980s, choice models, especially Logit model, are spread widely and rapidly over academic area, research institutes and consulting firms in Korea like other developed countries in the world. However, the process of calibration and parameter estimation for practical application was not clearly explained in previous papers and reports. This study tried to explain clearly the calibration process of mode choice step by step and suggested a forecasting mode choice model that can be applicable in real policy analysis by using household survey data of Pusan metropolitan are. The study also suggested a way of estimating attributes which was not observed during the household survey commonly such as travel time and cost of unchosen alternative modes. The study summarized the statistical results of model specification for four different Logit models as a process to upgrade model capability of explanation for real traveler's choice behaviors. By using the analysis results, it also calculated the value of travel time and compared them with the values of other previous studies to test reliability of the estimated model.