• Title/Summary/Keyword: express service

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A Genetic Algorithm Based Approach to the Profitable Tour Problem with Pick-up and Delivery

  • Lee, Hae-Kyeong;Ferdinand, Friska Natalia;Kim, Tai-Oun;Ko, Chang-Seong
    • Industrial Engineering and Management Systems
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    • v.9 no.2
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    • pp.80-87
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    • 2010
  • As express courier market expands rapidly, companies are exposed to fierce competition. To cope with struggle for their survival, they are continuously making efforts to improve their service system. Even if most of service centers are directly linked to a consolidation terminal in courier service network, some of them with regional disadvantages are operated in milk run type from/to the consolidation terminal, which is a traditional PDP (Pick-up and Delivery Problem). This study suggests an approach to solve the PDP with the objective of maximizing the incremental profit, which belongs to PTP (Profitable Tour Problem) class. After the PTP is converted to TSP (Traveling Salesman Problem) with the same objective, a heuristic algorithm based on GA (Genetic Algorithm) is developed and examined through an example problem in practice of a courier service company in Korea.

Flash Operation Group Scheduling for Supporting QoS of SSD I/O Request Streams (SSD 입출력 요청 스트림들의 QoS 지원을 위한 플래시 연산 그룹 스케줄링)

  • Lee, Eungyu;Won, Sun;Lee, Joonwoo;Kim, Kanghee;Nam, Eyeehyun
    • Journal of KIISE
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    • v.42 no.12
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    • pp.1480-1485
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    • 2015
  • As SSDs are increasingly being used as high-performance storage or caches, attention is increasingly paid to the provision of SSDs with Quality-of-Service for I/O request streams of various applications in server systems. Since most SSDs are using the AHCI controller interface on a SATA bus, it is not possible to provide a differentiated service by distinguishing each I/O stream from others within the SSD. However, since a new SSD interface, the NVME controller interface on a PCI Express bus, has been proposed, it is now possible to recognize each I/O stream and schedule I/O requests within the SSD for differentiated services. This paper proposes Flash Operation Group Scheduling within NVME-based flash storage devices, and demonstrates through QEMU-based simulation that we can achieve a proportional bandwidth share for each I/O stream.

Research on the Relationship Between Social Capital and Enterprise Performance in Supply Chain Environment

  • Li, Jian;Lee, Sang-Chun;Jeong, Ha-Eun
    • Journal of Korea Trade
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    • v.24 no.4
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    • pp.34-48
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    • 2020
  • Purpose - The rapid rise of e-commerce enterprises has led to the development of the logistics industry. At the same time, some enterprises are motivated by the interests to start reducing costs and inputs, which on the contrary leads to low quality of service, thus reducing customer satisfaction. In recent years, vicious competition, violent express delivery and lack of professionalism in the logistics market have led to high annual customer complaint rate, which has resulted in the company losing many loyal customers, but also unable to obtain new customers. Therefore, to pay attention to and understand the psychological needs of customers and improve the quality of logistics distribution service has become a pressing problem for Every express company. Design/methodology - By analyzing the problems existing in logistics distribution of express companies, this paper explores various factors affecting customer satisfaction and takes consumer sentiment as a mediating variable. Through questionnaires to collect relevant data, put forward hypotheses for empirical analysis, use two different software including SPSS 21.0 and AMOS 21.0 to analyze the information, draw conclusions and make recommendations. Findings - According to the above research results, the reliability, convenience, efficiency, professional can have a positive impact on customer satisfaction through the mediating effect of their sentiment, convenience and professional on consumer sentiment and satisfaction are more significant. Originality/value - This paper the establishment of distribution service indicators related to customer satisfaction and empirical analysis can not only enrich and supplement the distribution service quality indicator system studied by the former, but also provide a theoretical basis for future research.

A primary study of Rail Station Selection and Train Operation Management Plan with Transportation Demand (철도수송수요를 고려한 정차역 선정과 열차운행방안 -경부선 서울~조치원구간을 중심으로-)

  • 문대섭;정병현
    • Proceedings of the KSR Conference
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    • 2001.05a
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    • pp.80-87
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    • 2001
  • The purposes of this primary study are the selection of rail station and train operation management techniques for express-rail operation service at the convectional railway electrification. For these analyses, we used the KNR statistics and KROIS data of rail stations and train users by rail line. Therefore, we chose the important stations for express-rail operation of Kyongbu conventional rail line (esp. Seoul-Jochiwon section) through the rail transportation demand. and then, suggested primary operational management plan thorough the effects analyses of decreasing total travel time and increasing transportation demand by train speed-up. This study has some bounds and limits for proceeding, as it does, we excluded as followings: the conditionals of fate system, headways and train diagram, economic/financial analysis and technological assessment, and other railway technological infrastructures and a certain railcar specification, etc. . We propose to enlarge this study into a feasibility study of express or skip-stop operation service and compatible vehicle system decision considering with the best possible investment rail line, furthermore. in front of Kyongbu (Seoul-Busan) high-speed rail open in 2004, we have to try to progress the efficiencies of railway operation applying various train operation management plan.

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Computer simulation of passenger flow (컴퓨터 시뮬레이션에 의한 이용객의 교통에 관한 연구)

  • 차균현
    • 전기의세계
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    • v.27 no.1
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    • pp.35-44
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    • 1978
  • In this paper the best way of servicing to the waiting guests at the Express Bus Terminal, is to determined by the computer simulation. The mathematical model for the waiting guests is formulated with the statistics data by researching the waiting lines of the guests at the guests at the specified Express Bus Terminal. The waiting phenomena is simulated using Monte Carlo method to decide the proper number of window and the time for servicing. Finally it present the way of the improvement of service with the good results of simulation.

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A Markup Language for Describing the Linkage between Sensor Data and Service in the Ubiquitous Environment (유비쿼터스 환경에서 센서 데이터와 서비스의 연계를 표현하는 마크업 언어)

  • Lee, Hun-Soon;Jin, Seung-Il
    • The KIPS Transactions:PartD
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    • v.15D no.2
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    • pp.247-256
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    • 2008
  • In the ubiquitous environment, it is scattered all over our neighboring in many smart objects. These smart objects constantly produce the information and the amount of the generated information is massive. As the internet search engine came out to help us to find the useful data from the sea of the information connected to the internet, the sensor data stream processing middleware is appearing to make us to develop the ubiquitous service easily by extracting the meaningful information from the massive sensor data and delivering the extracted information to the application which makes our life convenient. We have to inform the information relating to the provided service to a middleware so that the ubiquitous service can be provided by using sensor data stream processing middleware. In this paper, we classify the information which is needed to express the ubiquitous service which uses sensor data for the service providing. And we propose a distinct markup language called Context-driven Service Markup Language (CSML) to effectively describe this information. We can easily express the various ubiquitous services which have to be provided in the various situations using proposed CSML.

The Concept design of Tilting system for Express tilting train for contentional line (기존선 고속화 차량의 틸팅시스템 개념설계 연구)

  • 김남포;유원희;최성규
    • Proceedings of the KSR Conference
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    • 2002.05a
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    • pp.351-358
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    • 2002
  • Tilting system allow the train to pass curve at higher speed without affecting passenger comfort. As the tilting trains offer the optimum means of providing faster and more comportable rail service with minimum of environmental disturbance and capital investment, more than 14 countries have now adopted or are about to adopt tilting train technology. The Korean National Railroad is also planing to apply faster tilting train to the areas where the High speed rail service are not provided. This paper shows the concept design of Bogie and Tilting system for 180 km/h Express tilting train for Korean conventional line, which was done as a part of the KNR's R&D project.

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Analysis on Factors Relating to External Medical Service Use of Health Insurance Patients Using Spatial Regression Analysis (공간효과분석을 이용한 건강보험 환자 관외 의료이용도와 관련된 요소분석)

  • Roh, Yun Ho
    • Health Policy and Management
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    • v.23 no.4
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    • pp.387-396
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    • 2013
  • Background: The purpose of this study was to analyze the association between areas of Korea Train Express (KTX) region and external medical service use in Korean society using spatial statistical model. Methods: The data which was used in this study was extracted from 2011 regional health care utilization statistics and health insurance key statistics from National Health Insurance Corporation. A total spatial units of 229 districts (si-gun-gu) were included in this study and spatial area was all parts of the country excepted Jeju, Ulleungdo island. We conducted Kruskal-Wallis test, correlation, Moran's I and hot-spot analysis. And after, ordinary linear regression, spatial lag, spatial error analysis was performed in order to find factors which were associated with external medical service use. The data was processed by SAS ver. 9.1 and Geoda095i (windows). Results: Moran's I of health insurance patients' external medical service use was 0.644. Also, population density, Seoul region, doctor factors positively associated with health insurance patients' external medical service. In contrast, average age, health care organization per 100 thousand were negatively associated with health insurance patients' external medical service use. Conclusion: The finding of this study suggested that health insurance patient's external medical service use correlated for seoul region in korea. The study results imply the need for more attention medical needs in the region (si-gun-gu unit) for health insurance patients of seoul region. It is important to adapt strategy to activation of primary health care as well as enhancing public health institution for prevent leakage of patients to other areas.