• Title/Summary/Keyword: Transport Performance

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Customer Loyalty and Logistics Service Performance in Maritime Transport : A Literature Review and Conceptual Model

  • Jang, Hyun Mi;Kim, Sang Youl
    • Journal of Navigation and Port Research
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    • v.36 no.9
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    • pp.753-761
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    • 2012
  • To achieve a differential advantage over competitors and protect their long-term interest, shipping lines have striven to find ways to maintain an ongoing relationship with shippers which can be achieved by attaining their loyalty. The benefits of loyal shippers are potentially huge in that they generate long-term revenue streams as well as provide cost savings as compared with attracting new shippers. Logistics service provided by shipping lines is identified as one of the effective tools for building customer loyalty. However, in a review of the literature none of the studies examine how logistics service creates customer loyalty, particularly between shipping lines and shippers. Consequently, the overarching purpose of this paper is to extend knowledge on logistics service performance and its relationship with customer loyalty in the unique context of maritime transport by proposing a new conceptual model based on an extensive literature review. The major contribution is to offer a new insight into the complex relationships between those 'soft' concepts in the context of maritime transport.

Conduction Mechanism of Charge Carriers in Electrodes and Design Factors for the Improvement of Charge Conduction in Li-ion Batteries

  • Akhtar, Sophia;Lee, Wontae;Kim, Minji;Park, Min-Sik;Yoon, Won-Sub
    • Journal of Electrochemical Science and Technology
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    • v.12 no.1
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    • pp.1-20
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    • 2021
  • In-depth knowledge of electrode processes is crucial for determining the electrochemical performance of lithium-ion batteries (LIBs). In particular, the conduction mechanisms of charged species in the electrodes, such as lithium ions (Li+) and electrons, are directly correlated with the performance of the battery because the overall reaction is dependent on the charge transport behavior in the electrodes. Therefore, it is necessary to understand the different electrochemical processes occurring in electrodes in order to elucidate the charge conduction phenomenon. Thus, it is essential to conduct fundamental studies on electrochemical processes to resolve the technical challenges and issues arising during the ionic and electronic conduction. Furthermore, it is also necessary to understand the transport of charged species as well as the predominant factors affecting their transport in electrodes. Based on such in-depth studies, potential approaches can be introduced to enhance the mobility of charged entities, thereby achieving superior battery performances. A clear understanding of the conduction mechanism inside electrodes can help overcome challenges associated with the rapid movement of charged species and provide a practical guideline for the development of advanced materials suitable for high-performance LIBs.

Testbed Implementation and Performance Evaluation of High Speed Transport Protocols using TEIN2 Networks (TEIN2를 활용한 고대역 전송계층 프로토콜 테스트베드 구축 및 성능 분석)

  • Lee, Gi-Ra;So, Sang-Ho;Choi, Yun-Chul;Park, Man-Kyu;Lee, Jae-Yong;Kim, Byung-Chul;Kim, Dae-Young
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.46 no.2
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    • pp.104-113
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    • 2009
  • Recently, high-speed Internet users and broadband network infrastructure are increasing. However, the TCP protocol widely used in the Internet is an appropriate transport only for the legacy Internet, it is inefficient for traffic transport for network environments with large bandwidth-delay product. In order to remedy this problem, there have been many researches about improved congestion control algorithms for broadband networks. In these studies, most of performance evaluation has been done by simulations. In this paper, after we reviewed the proposed high bandwidth transport layer protocols, we implemented a real testbed, measured the performance and analyzed the problems of high-speed transport protocols through the international research network TEIN2 between three nations, Korea, China, and Germany.

Performance Characteristics of a Polymer Electrolyte Fuel Cell with the Anodic Supply Mode (고분자 전해질 연료전지의 수소극 공급모드에 따른 성능특성)

  • Lee, Yong-Taek;Park, Cha-Sik;Heo, Jae-Hyeok;Kim, Yong-Chan
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.7 s.262
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    • pp.588-595
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    • 2007
  • The water transport inside a polymer electrolyte fuel cell (PEFC) varied according to the anodic supply mode. The performance characteristics of a PEFC which can be affected by the water transport were observed with the anodic supply mode. In the flow-through and recirculation mode the performance showed no reduction with time because the flow in the anode was not stagnated. In the dead-end mode, without any discharged gas, the water remains inside of the anode, which caused the reduction of the performance with the lapse of time. However, even in the dead-end mode, little reduction of the performance with time was shown when only the anode was humidified externally. It means that the back-diffusion was the major factor to the accumulation of water in the anode rather than external humidification.

Effect of Overlayer Thickness of Hole Transport Material on Photovoltaic Performance in Solid-Sate Dye-Sensitized Solar Cell

  • Kim, Hui-Seon;Lee, Chang-Ryul;Jang, In-Hyuk;Kang, Wee-Kyung;Park, Nam-Gyu
    • Bulletin of the Korean Chemical Society
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    • v.33 no.2
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    • pp.670-674
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    • 2012
  • The photovoltaic performance of solid-state dye-sensitized solar cells employing hole transport material (HTM), 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenyl-amine)-9,9'-spirobifluorene (spiro-MeOTAD), has been investigated in terms of HTM overlayer thickness. Two important parameters, soak time and spin-coating rate, are varied to control the HTM thickness. Decrease in the period of loading the spiro-MeOTAD solution on $TiO_2$ layer (soak time) leads to decrease in the HTM overlayer thickness, whereas decrease in spin-coating rate increases the HTM overlayer thickness. Photocurrent density and fill factor increase with decreasing the overlayer thickness, whereas open-circuit voltage remains almost unchanged. The improved photocurrent density is mainly ascribed to the enhanced charge transport rate, associated with the improved charge collection efficiency. Among the studied HTM overlayer thicknesses, ca. 230 nm-thick HTM overlayer demonstrates best efficiency of 4.5% at AM 1.5G one sun light intensity.

Experimental Study of Thermal Performance of Heat Pipe with Axial Trapezoidal Grooves (축방향 사다리꼴 그루브 히트파이프의 열성능에 대한 실험적 연구)

  • Suh, Jeong-Se;Lee, Woon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.4
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    • pp.407-414
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    • 2003
  • Analysis and experiment are performed to investigate the thermal performance of a heat pipe with axial grooves. The heat pipe was designed in a 6.5 mm I.D., 17 axial trapezoidal grooves. 1000 mm long tube of aluminium, and ammonia as working fluid. A mathematical equations fur heat pipe with axial grooves is formulated to obtain the capillary limitation on heat transport rate in a steady state. As a result, heat transport factor of heat pipe has the maximum at the operating temperature of 293K in 0m elevation. As the elevation of heat pipe increases. the heat transport factor of the heat pipe is reduced markedly, comparing with that of horizontal elevation of the heat pipe. It may be considered that such behavior of heat pipe is caused by the working fluid swarmed back to the condenser port due to gravity force and supercooled by a coolant of heat exchanger. Analytical results of heat transport factor are in a good agreement with those of experiment.

Measurements and Assessments on Shielding Performance of FCTC10 60Co Transport Container

  • Zhuang, Dajie;Zhang, Guoqing;Li, Guoqiang;Wang, Renze
    • Journal of Radiation Protection and Research
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    • v.41 no.3
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    • pp.310-314
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    • 2016
  • Background: FCTC10 container is designed to transport $^{60}Co$ radioactive sources used in irradiation industry. It belongs to Type B(U) Category III (yellow) package when being loaded with a $^{60}Co$ source of $1.8{\times}10^5$ Ci. Materials and Methods: The container is constituted of shielding container, basket, protective cover and bracket. Shielding ability is provided mainly by stainless steel shells, tungsten alloy and lead among steel shells. Radiation level around the container has been calculated with both Monte Carlo simulations and measurements. Results and Discussion: It is proven that the shielding performance of the container fulfills the requirements in GB11806-2004 (Regulations for the safe transport of radioactive material, China Standard Press). Exposure doses to workers and to critical groups of public were calculated based on hypothetical exposure scene according to transport practice experience. Conclusion: The results show that doses to workers and public are less than the constraint dose considered in design, and the radiation level would be increased less than a factor of 2 under design basis accidents.

An Experimental Investigation on the Operating Characteristics of a Reversible Loop Heat Pipe (가역 루프 히트파이프의 작동특성에 관한 실험적 연구)

  • Kim Bong-Hun;Choi Joon-Min
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.18 no.3
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    • pp.231-239
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    • 2006
  • An experimental investigation of a Reversible Loop Heat Pipe (RLHP) was conducted to determine the operating limits and performance characteristics as functions of the thermophysical parameters, the heat input, and the cooling intensity. Variations in both temperature and heat transport capacity were measured and analyzed in order to accurately evaluate the transient operating characteristics. In addition, the maximum heat transport as a function of the mean evaporator temperature, the ratio of heat transport to heater input power as a function of the mean evaporator temperature, and the overall thermal resistance as a function of the overall heat transport capacity were examined as well. Results indicated that the cooling intensity played an important role on the operating characteristics and performance limitation. The maximum heat transports corresponding to cooling intensity $72W/^{\circ}C$ and $290W/^{\circ}C$ were 446 W and 924 W, respectively. Also, observation of the startup characteristics indicated that the mean evaporator temperature should be maintained between $40^{\circ}C$ and $60^{\circ}C$, and overall thermal resistance were measured as $0.02^{\circ}C/W$.

SOAP Performance Analysis (SOAP 성능 분석)

  • Song, Byungkwen;Kang, Sunmee;Lee, Sukhee
    • Journal of IKEEE
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    • v.17 no.2
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    • pp.159-162
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    • 2013
  • In this paper, we make a performance analysis of two kinds of platforms, JAVA and .NET, about SOAP(Simple Object Access Protocol). SOAP is able to use various transport layer protocol but in this paper we suggested methods of performance analysis with using HTTP, TCP, UDP and then we made an performance analysis on the basis of suggested methods. The results of performance analysis may be deduced differently by a system environment and loaded degree of network. Therefore, for precise performance analysis, we made same environment and proceeded.

Effects of transport stress on physiological responses and milk production in lactating dairy cows

  • Hong, Heeok;Lee, Eunchae;Lee, In Hyung;Lee, Sang-Rak
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.3
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    • pp.442-451
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    • 2019
  • Objective: This study was conducted to investigate the effect of transport stress on physiological and hematological responses and milk performance in lactating dairy cows. Methods: Ten lactating dairy cows were randomly divided into 2 groups. The treatment group (TG) was transported 200 km for 4 h by truck, and the control group (NTG) was restrained by stanchion for 4 h in Konkuk University farm. Blood and milk samples were collected at 24 h pre-transport; 1, 2, and 4 h during transport; and 2, 24, and 48 h post-transport. Milk yields were measured at 24 h pre-transport, 0 h during transport, and 24, 48, and 72 h post-transport. Results: Leukocyte, neutrophil, and monocyte numbers in the TG were significantly higher than those of the NTG at each experimental time point. Lymphocyte numbers in the TG were significantly (p<0.05) higher than those of the NTG at 48 h post-transport. Additionally, the neutrophil:lymphocyte ratio of the TG was 45% and 46% higher than that of the NTG at 4 h during transport and 2 h post-transport, respectively. There were no significant differences in erythrocyte numbers, hemoglobin concentrations, platelet numbers, and hematocrit percentages between two groups. Cortisol levels in the TG were significantly (p<0.05) higher than those in the NTG. Milk yields in the TG were lower than those in the NTG. The somatic cell count (SCC) of the TG was significantly (p<0.05) higher than that of the NTG at 1 and 2 h during transport; that of the TG increased dramatically at 1 h during transport and gradually decreased subsequently. Conclusion: Transport stress increased blood parameters including leucocyte, neutrophil, and monocyte numbers by increased cortisol levels, but did not affect erythrocytes, hemoglobin and hematocrit levels. Additionally, transport resulted in a decrease in milk yield and reduced milk quality owing to an increase in milk SCC.