• Title/Summary/Keyword: routing path

Search Result 980, Processing Time 0.023 seconds

Voronoi-Based Search Scheme for Road Network Databases (도로 망 데이터베이스를 위한 보로노이 기반의 탐색 방안)

  • Kim, Dae-Hoon;Hwang, Een-Jun
    • Journal of IKEEE
    • /
    • v.11 no.4
    • /
    • pp.348-357
    • /
    • 2007
  • Due to the improved performance and cost of personal mobile devices and rapid progress of wireless communication technology, the number of users who utilize these devices is increasing. This trend requires various types of services be available to users. So far, there have been many solutions provided for the shortest path problem. But, technologies which can offer various recommendation services to user depending on user’s current location are focused on Euclidean spaces rather than road network. Thus, in this paper, we extend the previous work to satisfy this requirement on road network database. Our proposed scheme requires pre-computation for the efficient query processing. In the preprocessing step, we first partition the input road network into a fixed number of Voronoi polygons and then pre-compute routing information for each polygon. In the meantime, we select the number of Voronoi polygons in proposition to the scale of road network. Through this selection, the required size of pre-computation is linearly increasing to the size of road network. Using this pre-computated information, we can process queries more quickly. Through experiments, we have shown that our proposed scheme can achieve excellent performance in terms of scheduling time and the number of visited nodes.

  • PDF

Development of distributed inundation routing method using SIMOD method (SIMOD 기법을 이용한 분포형 침수 추적 기법 개발)

  • Lee, Suk Ho;Lee, Dong Seop;Kim, Jin Man;Kim, Byung Sik
    • Journal of Korea Water Resources Association
    • /
    • v.49 no.7
    • /
    • pp.579-588
    • /
    • 2016
  • Changes in precipitation due to climate change is made to induce the local and intensive rainfall, it is increasing damage caused by inland inundation. Therefore, it requires a technique for predicting damage caused by flooding. In this study, in order to determine whether this flood inundated by any route when the levee was destroyed, Which can simulate the path of the flood inundation model was developed for the SIMOD (Simplified Inundation MODel). Multi Direction Method (MDM) for differential distributing the adjacent cells by using the slope and Flat-Water Assumption (FWA)-If more than one level higher in the cell adjacent to the cell level is the lowest altitude that increases the water level is equal to the adjacent cells- were applied For the evaluation of the model by setting the flooding scenarios were estimated hourly range from the target area. SIMOD model can significantly reduce simulation time because they use a simple input data of topography (DEM) and inflow flood. Since it is possible to predict results within minutes, if you can only identify inflow flood through the runoff model or levee collapse model. Therefore, it could be used to establish an evacuation plan due to flooding, such as EAP (Emergency Action Plan).

A Multistage Authentication Strategy for Reliable N-to-N Communication in CGSR based Mobile Ad Hoc Networks (CGSR 기반의 이동 애드 흑 네트워크에서 신뢰성 있는 통신을 위한 노드간 인증 기법)

  • Lee Hyewon K.;Mun Youngsong
    • Journal of KIISE:Information Networking
    • /
    • v.32 no.6
    • /
    • pp.659-667
    • /
    • 2005
  • A Mobile Ad Hoc Network(MANET) is a multi hop wireless network with no prepared base stations or centralized administrations, where flocks of peer systems gather and compose a network. Each node operates as a normal end system in public networks. In addition to it, a MANET node is required to work as a router to forward traffic from a source or intermediate node to others. Each node operates as a normal end system in public networks, and further a MANET node work as a router to forward traffic from a source or intermediate node to the next node via routing path. Applications of MANET are extensively wide, such as battle field or any unwired place; however, these are exposed to critical problems related to network management, node's capability, and security because of frequent and dynamic changes in network topology, absence of centralized controls, restricted usage on network resources, and vulnerability oi mobile nodes which results from the special MANET's character, shared wireless media. These problems induce MANET to be weak from security attacks from eavesdropping to DoS. To guarantee secure authentication is the main part of security service In MANET because networks without secure authentication are exposed to exterior attacks. In this paper, a multistage authentication strategy based on CGSR is proposed to guarantee that only genuine and veritable nodes participate in communications. The proposed authentication model is composed of key manager, cluster head and common nodes. The cluster head is elected from secure nodes, and key manager is elected from cluster heads. The cluster head will verify other common nodes within its cluster range in MANET. Especially, ID of each node is used on communication, which allows digital signature and blocks non repudiation. For performance evaluation, attacks against node authentication are analyzed. Based on security parameters, strategies to resolve these attacks are drawn up.

APPLYING ENTERPRISE GIS TO DISASTER MANAGEMENT AT KANGWON PROVINCE

  • Yoon, Hoon-Joo;Ryu, Joong-Hi;Kim, Jung-Dai;Park, Hong-Gi
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.9 no.2 s.18
    • /
    • pp.29-36
    • /
    • 2001
  • The purpose of this paper is to describe the Disaster Management System Development of Enterprise GIS at the Kangwon Province in Korea. This project is included into 'the Kangwon Enterprise GIS 21 plan'. The Division of Disaster Management is in the middle of the 2-year project of the Disaster Management System development, appropriate for business performed at the Departments of Forestry, Culture, Environment, Tourism, etc. At the 1st phase of CIS implementation, for more than half a year we focused on the necessity of management of disasters. In the planning process, we needed long-term information on the whole area of Kangwon. In the assessment and response processes, we needed real-time data from Korean Meteorological Administration and other agencies. All the above information was carefully studied and referred to. ESRI's new GIS technologies solve the natural hazard/disaster problems. For example, hazardous materials routing often needs to be found the least expensive path through a roadway network. In the circumstances given, we can choose the departure point and destination of the vehicle, which carries the materials. It's also possible to minimize overall risk and costs of disaster problems by making a plan of people and possessions evacuation from the disaster area in short time limits. We can meet all the above goals using the latest ESRI's technologies.

  • PDF

unifying solution method for logical topology design on wavelength routed optical networks (WDM의 논리망 구성과 파장할당 그리고 트래픽 라우팅을 위한 개선된 통합 해법)

  • 홍성필
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.25 no.9A
    • /
    • pp.1452-1460
    • /
    • 2000
  • A series of papers in recent literature on logical topology design for wavelength routed optical networks have proposed mathematical models and solution methods unifying logical topology design wavelength assignment and traffic routing. The most recent one is by Krishnaswamy and Sivarajan which is more unifying and complete than the previous models. Especially the mathematical formulation is an integer linear program and hence regarded in readiness for an efficient solution method compared to the previous nonlinear programming models. The solution method in [7] is however elementary one relying on the rounding of linear program relaxation. When the rounding happens to be successful it tends to produce near-optimal solutions. In general there is no such guarantee so that the obtained solution may not satisfy the essential constraints such as logical -path hop-count and even wavelength number constraints. Also the computational efforts for linear program relaxation seems to be too excessive. In this paper we propose an improved and unifying solution method based on the same to be too excessive. In this paper we propose an improved and unifying solution method based on the same model. First its computation is considerably smaller. Second it guarantees the solution satisfies all the constraints. Finally applied the same instances the quality of solution is fairly competitive to the previous near optimal solution.

  • PDF

Congestion Control based on Genetic Algorithm in Wireless Sensor Network (무선 센서 네트워크에서 유전자 알고리즘 기반의 혼잡 제어)

  • Park, Chong-Myung;Lee, Joa-Hyoung;Jung, In-Bum
    • Journal of KIISE:Information Networking
    • /
    • v.36 no.5
    • /
    • pp.413-424
    • /
    • 2009
  • Wireless sensor network is based on an event driven system. Sensor nodes collect the events in surrounding environment and the sensing data are relayed into a sink node. In particular, when events are detected, the data sensing periods are likely to be shorter to get the more correct information. However, this operation causes the traffic congestion on the sensor nodes located in a routing path. Since the traffic congestion generates the data queue overflows in sensor nodes, the important information about events could be missed. In addition, since the battery energy of sensor nodes exhausts quickly for treating the traffic congestion, the entire lifetime of wireless sensor networks would be abbreviated. In this paper, a new congestion control method is proposed on the basis of genetic algorithm. To apply genetic algorithm, the data traffic rate of each sensor node is utilized as a chromosome structure. The fitness function of genetic algorithm is designed from both the average and the standard deviation of the traffic rates of sensor nodes. Based on dominant gene sets, the proposed method selects the optimal data forwarding sensor nodes for relieving the traffic congestion. In experiments, when compared with other methods to handle the traffic congestion, the proposed method shows the efficient data transmissions due to much less queue overflows and supports the fair data transmission between all sensor nodes as possible. This result not only enhances the reliability of data transmission but also distributes the energy consumptions across the network. It contributes directly to the extension of total lifetime of wireless sensor networks.

Systematic Literature Review for HRD in Korea Franchise Business (국내 프랜차이즈 사업에서의 인적자원개발에 관한 체계적 문헌 고찰)

  • KIM, Eunsung;LEE, Sang-Seub
    • The Korean Journal of Franchise Management
    • /
    • v.10 no.2
    • /
    • pp.33-47
    • /
    • 2019
  • Purpose - The purpose of this study is to classify and analyze existing studies from various angles through systematic literature review of how human resources development has been researched in the domestic franchise business. These studies are intended to suggest the direction in which human resource development research should be conducted in the future in the franchise business. Research design, data, and methodology - This study is based on systematic literature review methodology. It has gone through the process of subject language setting, literature search routing, search term selection, literature selection, literature classification and literature analysis. The systematic literature review identified 59 peer-reviewed dissertations and scientific journal publications on the subject of HRD in Korea franchise business. Result - This study analyzed by research methods, research industries, research population and dependent variable using the systematic review process. The literature studied in the 2000s mainly led to research on education and training of franchise employees in beauty franchise business. In the literature studied since 2010, human resources development was mainly studied in the supervisor in the restaurant franchise business, and in the study of competence rather than education and training. According to the research methods, statistical methods were mostly relatively simple, such as t-test or one-way distribution analysis until the 2000s, and after 2010, in-depth and structural studies using multiple return analysis, structural method analysis, path analysis, multi-dimensional scale analysis, AHP, etc were conducted. When classified by study dependant, early research until the 2000s focused on the study of education and training, which is an independent variable, on the satisfaction of education programs, job satisfaction, and immersion. On the other hand, studies conducted since 2010 have produced more complex results using various medium variants, and those related to management performance and relationship performance have been mainly studied, rather than the satisfaction of the education itself. Conclusions - While the domestic franchise business is expanding in terms of quantity, such as the number of franchises and franchises, the development in terms of quality for the joint growth of franchises and franchisees is still lacking. In order for the franchisee to continue to grow with each other, the franchisee must identify and develop their current performance or expected capabilities through capacity modeling at various targets and levels.

Re-Analysis of Clark Model Based on Drainage Structure of Basin (배수구조를 기반으로 한 Clark 모형의 재해석)

  • Park, Sang Hyun;Kim, Joo Cheol;Jeong, Dong Kug;Jung, Kwan Sue
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.33 no.6
    • /
    • pp.2255-2265
    • /
    • 2013
  • This study presents the width function-based Clark model. To this end, rescaled width function with distinction between hillslope and channel velocity is used as time-area curve and then it is routed through linear storage within the framework of not finite difference scheme used in original Clark model but analytical expression of linear storage routing. There are three parameters focused in this study: storage coefficient, hillslope velocity and channel velocity. SCE-UA, one of the popular global optimization methods, is applied to estimate them. The shapes of resulting IUHs from this study are evaluated in terms of the three statistical moments of hydrologic response functions: mean, variance and the third moment about the center of IUH. The correlation coefficients to the three statistical moments simulated in this study against these of observed hydrographs were estimated at 0.995 for the mean, 0.993 for the variance and 0.983 for the third moment about the center of IUH. The shape of resulting IUHs from this study give rise to satisfactory simulation results in terms of the mean and variance. But the third moment about the center of IUH tend to be overestimated. Clark model proposed in this study is superior to the one only taking into account mean and variance of IUH with respect to skewness, peak discharge and peak time of runoff hydrograph. From this result it is confirmed that the method suggested in this study is useful tool to reflect the heterogeneity of drainage path and hydrodynamic parameters. The variation of statistical moments of IUH are mainly influenced by storage coefficient and in turn the effect of channel velocity is greater than the one of hillslope velocity. Therefore storage coefficient and channel velocity are the crucial factors in shaping the form of IUH and should be considered carefully to apply Clark model proposed in this study.

Energy-Efficient Division Protocol for Mobile Sink Groups in Wireless Sensor Network (무선 센서 네트워크에서 이동 싱크 그룹의 분리를 지원하기 위한 라우팅 프로토콜)

  • Jang, Jaeyoung;Lee, Euisin
    • KIPS Transactions on Computer and Communication Systems
    • /
    • v.6 no.1
    • /
    • pp.1-8
    • /
    • 2017
  • Communications for mobile sink groups such as rescue teams or platoons bring about a new challenging issue for handling mobility in wireless sensor networks. To do this, many studies have been proposed to support mobile sink groups. When closely looking at mobile sink groups, they can be divided into (multiple) small groups according to the property of applications. For example, a platoon can be divided into multiple squads to carry out its mission in the battle field. However, the previous studies cannot efficiently support the division of mobile sink groups because they do not address three challenging issues engendered by the mobile sink group division. The first issue is to select a leader sink for a new small mobile sink group. The efficient data delivery from a source to small mobile sink groups is the second issue. Last, the third issue is to share data between leader sinks of small mobile sink groups. Thus, this paper proposes a routing protocol to efficiently support the division of mobile sink groups by solving the three challenging issues. For the first issue, the proposed protocol selects a leader sink of a new small mobile sink group which provide a minimum summation of the distance between the new leader sink and the previous leader sink and the distance from the new leader sink to all of its member sinks. For the efficient data delivery from a source to small mobile sink groups in the second issue, the proposed protocol determines the path to minimize the data dissemination distance from source to small mobile sink group by calculating with the location information of both the source and the leader sinks. With regard to the third issue, the proposed protocol exploits member sinks located among leader sinks to provide efficient data sharing among leaders sinks by considering the location information of member sinks. Simulation results verified that the proposed protocol is superior to the previous protocol in terms of the energy consumption.

Development of Intelligent ATP System Using Genetic Algorithm (유전 알고리듬을 적용한 지능형 ATP 시스템 개발)

  • Kim, Tai-Young
    • Journal of Intelligence and Information Systems
    • /
    • v.16 no.4
    • /
    • pp.131-145
    • /
    • 2010
  • The framework for making a coordinated decision for large-scale facilities has become an important issue in supply chain(SC) management research. The competitive business environment requires companies to continuously search for the ways to achieve high efficiency and lower operational costs. In the areas of production/distribution planning, many researchers and practitioners have developedand evaluated the deterministic models to coordinate important and interrelated logistic decisions such as capacity management, inventory allocation, and vehicle routing. They initially have investigated the various process of SC separately and later become more interested in such problems encompassing the whole SC system. The accurate quotation of ATP(Available-To-Promise) plays a very important role in enhancing customer satisfaction and fill rate maximization. The complexity for intelligent manufacturing system, which includes all the linkages among procurement, production, and distribution, makes the accurate quotation of ATP be a quite difficult job. In addition to, many researchers assumed ATP model with integer time. However, in industry practices, integer times are very rare and the model developed using integer times is therefore approximating the real system. Various alternative models for an ATP system with time lags have been developed and evaluated. In most cases, these models have assumed that the time lags are integer multiples of a unit time grid. However, integer time lags are very rare in practices, and therefore models developed using integer time lags only approximate real systems. The differences occurring by this approximation frequently result in significant accuracy degradations. To introduce the ATP model with time lags, we first introduce the dynamic production function. Hackman and Leachman's dynamic production function in initiated research directly related to the topic of this paper. They propose a modeling framework for a system with non-integer time lags and show how to apply the framework to a variety of systems including continues time series, manufacturing resource planning and critical path method. Their formulation requires no additional variables or constraints and is capable of representing real world systems more accurately. Previously, to cope with non-integer time lags, they usually model a concerned system either by rounding lags to the nearest integers or by subdividing the time grid to make the lags become integer multiples of the grid. But each approach has a critical weakness: the first approach underestimates, potentially leading to infeasibilities or overestimates lead times, potentially resulting in excessive work-inprocesses. The second approach drastically inflates the problem size. We consider an optimized ATP system with non-integer time lag in supply chain management. We focus on a worldwide headquarter, distribution centers, and manufacturing facilities are globally networked. We develop a mixed integer programming(MIP) model for ATP process, which has the definition of required data flow. The illustrative ATP module shows the proposed system is largely affected inSCM. The system we are concerned is composed of a multiple production facility with multiple products, multiple distribution centers and multiple customers. For the system, we consider an ATP scheduling and capacity allocationproblem. In this study, we proposed the model for the ATP system in SCM using the dynamic production function considering the non-integer time lags. The model is developed under the framework suitable for the non-integer lags and, therefore, is more accurate than the models we usually encounter. We developed intelligent ATP System for this model using genetic algorithm. We focus on a capacitated production planning and capacity allocation problem, develop a mixed integer programming model, and propose an efficient heuristic procedure using an evolutionary system to solve it efficiently. This method makes it possible for the population to reach the approximate solution easily. Moreover, we designed and utilized a representation scheme that allows the proposed models to represent real variables. The proposed regeneration procedures, which evaluate each infeasible chromosome, makes the solutions converge to the optimum quickly.