• Title/Summary/Keyword: Fleet Management System

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An Air-Interface for Ad Hoc Networks Supporting High Mobility

  • Lott, Matthias;Ebner, Andre;Meincke, Michael;Halfmann, Rudiger;Wischhof, Lars;Schulz, Egon;Rohling,
    • Journal of Communications and Networks
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    • v.6 no.4
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    • pp.295-306
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    • 2004
  • In this paper, a novel air-interface is presented for Fleet-Net1, a self-organizing network for inter-vehicle and vehicle-toroadsidecommunication. The air-interface is based upon the lowchip-rate version of UMTS/TDD. To adapt the cellular UMTS standard to an air-interface for ad hoc networks, changes of the physical layer, medium access control sub-layer and radio resource management are required. An overview of the required modifications is given here. Particularly, a decentralized synchronization mechanism is presented and analyzed by means of simulations. Furthermore, changes for the medium access control are explained in detail, which allow for an efficient operation in partly meshed networks and prioritization. Performance results of the overall system considering throughput and delay are derived by means of analytical evaluations and event-driven simulations. Based on realistic mobility models, it is shown that the presented solution provides a robust communication platform even in vehicular environments. The proposed air-interface is a cost-effective solution not only for inter-vehicle communication, but also for ad hoc networking in general, benefiting from the mass-market of UMTS.

Comparison of Intelligent Charging Algorithms for Electric Vehicles to Reduce Peak Load and Demand Variability in a Distribution Grid

  • Mets, Kevin;D'hulst, Reinhilde;Develder, Chris
    • Journal of Communications and Networks
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    • v.14 no.6
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    • pp.672-681
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    • 2012
  • A potential breakthrough of the electrification of the vehicle fleet will incur a steep rise in the load on the electrical power grid. To avoid huge grid investments, coordinated charging of those vehicles is a must. In this paper, we assess algorithms to schedule charging of plug-in (hybrid) electric vehicles as to minimize the additional peak load they might cause. We first introduce two approaches, one based on a classical optimization approach using quadratic programming, and a second one, market based coordination, which is a multi-agent system that uses bidding on a virtual market to reach an equilibrium price that matches demand and supply. We benchmark these two methods against each other, as well as to a baseline scenario of uncontrolled charging. Our simulation results covering a residential area with 63 households show that controlled charging reduces peak load, load variability, and deviations from the nominal grid voltage.

Extending SQL for Moving Objects Databases

  • Nam, Kwang-Woo;Lee, Jai-Ho;Kim, Min-Soo
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.138-143
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    • 2002
  • This paper describes a framework for extending GIS databases to support moving object data type and query language. The rapid progress of wireless communications, positioning systems, and mobile computing devices have led location-aware applications to be essential components for commercial and industrial systems. Location-aware applications require GIS databases system to represent moving objects and to support querying on the motion properties of objects. For example, fleet management applications may require storage of information about moving vehicles. Also, advanced CRM(Customer Relationship Management) applications may require to store and query the trajectories of mobile phone users. In this trend, maintaining consistent information about the location of continuously moving objects and processing motion-specific queries is challenging problem. We formally define a data model and query language for mobile objects that includes complex evolving spatial structure, and propose core algebra to process the moving object query language. Main profit of proposed moving objects query language and algebra is that proposed model can be constructed on the top of GIS databases.

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Development of AVL-GIS System Using IDGPS and Wireless Communication Techniques (IDGPS 와 무선통신을 이용한 AVL-GIS 시스템개발)

  • 안충현;양종윤;최종현
    • Spatial Information Research
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    • v.7 no.2
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    • pp.209-221
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    • 1999
  • In this research, AVL-GIS(Automatic Vehicle Location System linked with Geographic Information System) system was developed using integration of core techniques of GIS engine written by Java language, GOS(Global Positioning System) and wireless telecommunication interfacing techniques. IDGPS(Inverted differential GPS) techniques was employed to estimate accurate position of mobile vehicle and to supervise their path from AVL-GLS control center system. Between mobile vehicle and AVL-GLS control center system which has spatial data analysis function, road network and rleate ddata base were connected wireless phone to communicate for position an dmessage in real time. The developed system from this research has more enhanced GIS functions rather than previous AVL oriented system which has MDT for message display and voice communication only. This system can support build-up application system such as fleet management like bus, taxi, truck, disaster and emergency and monitoring of transportation status for customer s order via web browser in filed of EC/CALS in low cost.

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Optimal Spare Provisioning for Group Replacement Policy (경제적인 그룹교체보전을 위한 최적 예비품 재고수준의 결정)

  • Yoo, Young Kwan;Park, Roh Gook
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.9 no.2
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    • pp.81-86
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    • 2014
  • In this paper, a jointly optimal group replacement and spare provisioning policy is presented. Most maintenance policies assume that the spare inventory is always available, but in practice the maintenance schedule is affected by the availability of spare inventory. We present a maintenance-inventory model which jointly optimizes the group replacement interval and spare ordering quantity. Group replacement policy is used when a group of units are put in operation simultaneously. The operating fleet is replaced altogether at a predetermined number of units are failed. A sufficient level of spare inventory is carried to perform a number of group replacement. A cost rate expression which considers the group maintenance cost and inventory holding cost is derived and a heuristic method for searching the optimum value of decision variables is suggested. Numerical examples demonstrate the analytical results and the performance of the presented model.

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The nuclear fuel cycle code ANICCA: Verification and a case study for the phase out of Belgian nuclear power with minor actinide transmutation

  • Rodriguez, I. Merino;Hernandez-Solis, A.;Messaoudi, N.;Eynde, G. Van den
    • Nuclear Engineering and Technology
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    • v.52 no.10
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    • pp.2274-2284
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    • 2020
  • The Nuclear Fuel Cycle Code "ANICCA" has been developed by SCK•CEN to answer particular questions about the Belgian nuclear fleet. However, the wide range of capabilities of the code make it also useful for international or regional studies that include advanced technologies and strategies of cycle. This paper shows the main features of the code and the facilities that can be simulated. Additionally, a comparison between several codes and ANICCA has also been made to verify the performance of the code by means of a simulation proposed in the last NEA (OECD) Benchmark Study. Finally, a case study of the Belgian nuclear fuel cycle phase out has been carried out to show the possible impact of the transmutation of the minor actinides on the nuclear waste by the use of an Accelerator Driven System also known as ADS. Results show that ANICCA accomplishes its main purpose of simulating the scenarios giving similar outcomes to other codes. Regarding the case study, results show a reduction of more than 60% of minor actinides in the Belgian nuclear cycle when using an ADS, reducing significantly the radiotoxicity and decay heat of the high-level waste and facilitating its management.

Study on effects and strategies of Korean tuna purse seine fishery affected by conservation management measures of Western and Central Pacific Fisheries Commission (중서부태평양수산위원회 보존관리조치가 우리나라 다랑어선망어업에 미친 영향과 향후 대응 방안)

  • LEE, Mi-Kyung;LEE, Sung-Il;LEE, Chun-Woo;KIM, Doo-Nam;KU, Jeong-Eun
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.52 no.3
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    • pp.197-208
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    • 2016
  • The WCPFC CMMs related to tropical tunas have been strongly restricting fishing capacity and operating activities of main fisheries, especially purse seine fishery. In terms of changes in fishing trend by implementing relevant measures of FAD set, the number of FAD set by Korean purse seine fleet showed a decreasing pattern with the lowest level of FAD set proportion among major distant water fishing nations. With regards to the FAD closure, there was no significant change in fishing effort but a drop in catch, especially bigeye tuna during the period of FAD closure. Moreover, it showed closely similar trends between the number of FAD set and bigeye tuna catch. In terms of measures related to the high sea area including a ban on fishing on the HSP and limitation of fishing days on the high sea by flag state, proportions of catch and effort on the high sea had sharply declined after implementing those measures. As relevant measures are expected to be strengthened, it should pay attention to change of coastal nations policies and focus on improving fishing efficiency of unassociated school set with multi-pronged efforts.

Risk Assessment for Retrofitting an Electrolysis Type Ballast Water Treatment System on an Exiting Vessel (현존선에 전기분해방식 선박평형수 처리장치 설치를 위한 위험도 평가 분석)

  • JEE, Jae-Hoon
    • Journal of Fisheries and Marine Sciences Education
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    • v.29 no.3
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    • pp.665-676
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    • 2017
  • Over the past several years, sea trade have increased traffic by ships which highlighted a problem of unwanted species invading the surrounding seas through ship's ballast water discharge. Maritime trade volume has continuously increased worldwide and the problem still exists. The respective countries are spending billions of dollars in an effort to clean up the contamination and prevent pollution. As part of an effort to solve marine environmental problem, BWM(Ballast Water Management) convention was adopted at a diplomatic conference on Feb. 13 2004. In order to comply harmoniously this convention by each country. This convention will be effective after 12 months from the date which 30 countries ratified accounting for more than 35% of the world merchant shipping volume. On Sep. 8 2016, Finland ratified this convention and effective condition was satisfied as 52 states and world merchant vessel fleet 35.1441%. Thus, after Sep. 8 2017, all existing vessels shall be equipped with BWTS(Ballast Water Treatment System) in accordance with D-2 Regulation, which physically handles ballast water from ballast water exchange system(D-1 Regulation). In this study, we analyzed in detail the optimal design method using the Risk Analysis and Evaluation technique which is mainly used in the manufacturing factory or the risky work site comparing with the traditional design concept method applying various criteria. The Risk Assessment Method is a series of processes for finding the Risk Factors in the design process, analyzing a probility of the accident and size of the accident and then quantifying the Risk Incidence and finally taking measures. In this study, this method was carried out for Electrolysis treatment type on DWT 180K Bulk Carrier using "HAZOP Study" method among various methods. In the Electrolysis type, 63 hazardous elements were identified.

Forecasting Bunker Price Using System Dynamics (시스템 다이내믹스를 활용한 선박 연료유 가격 예측)

  • Choi, Jung-Suk
    • Journal of Korea Port Economic Association
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    • v.33 no.1
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    • pp.75-87
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    • 2017
  • The purpose of this study is to utilize the system dynamics to carry out a medium and long-term forecasting analysis of the bunker price. In order to secure accurate bunker price forecast, a quantitative analysis was established based on the casual loop diagram between various variables that affects bunker price. Based on various configuration variables such as crude oil price which affects crude oil consumption & production, GDP and exchange rate which influences economic changes and freight rate which is decided by supply and demand in shipping and logistic market were used in accordance with System Dynamics to forecast bunker price and then objectivity was verified through MAPEs. Based on the result of this study, bunker price is expected to rise until 2029 compared to 2016 but it will not be near the surge sighted in 2012. This study holds value in two ways. First, it supports shipping companies to efficiently manage its fleet, offering comprehensive bunker price risk management by presenting structural relationship between various variables affecting bunker price. Second, rational result derived from bunker price forecast by utilizing dynamic casual loop between various variables.

Development of an Equipment Operating System for Effective Earthwork Operations (효율적인 토공작업을 위한 건설장비 운영시스템 개발)

  • Ahn, Seo-Hyun;Kim, Sung-Keun;Lim, So-Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.37 no.1
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    • pp.153-166
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    • 2017
  • Recently, the construction industry has been pursuing economical construction by introducing improved construction equipment and methods. However, in many cases, the equipment operation according to the intuition of the field manager and in the manner of traditional methods impedes the increase in effectiveness in terms of productivity and economy. The performance of new construction equipment has rapidly improved; however, the maximum effect of mechanized construction cannot be obtained unless the effective management and operation methods are implemented. According to the expert survey, it has been discovered that the problems of conventional construction equipment operation methods can be classified into several categories: allocation of construction equipment that is not suitable for the construction work, the combination of equipment that does not take into consideration real-time field situations, the decline in the skill of the construction equipment drivers, and lack of real-time access to necessary information. This paper proposes a construction equipment management system to solve these problems. The construction equipment management system can provide a method to maximize the work rate of the construction equipment fleet by developing an equipment allocation plan based on field conditions, whenever necessary, and transferring this information to the construction equipment drivers in real time. Ultimately, it is believed that the application of the construction equipment operation system in the field will make it possible to reduce carbon emissions by improving productivity and reducing fuel consumption.