• Title/Summary/Keyword: transport efficiency

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A Study on the Construct Building of Service Quality in the International Passenger Terminal (해상여객터미널에 있어서 서비스품질 구성요인 개발에 관한 연구)

  • Kwon, Jae-Hyun;Han, Chul-Hwan;Lee, Su-Ho
    • Journal of Korea Port Economic Association
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    • v.25 no.1
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    • pp.107-124
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    • 2009
  • In order to create value for maritime tourism industry, new port infrastructures have been planned, improvements in passenger terminal services have been designed, and new maritime transport technologies have been applied, so that ports improve their efficiency and the quality of their service more than their national and international competitors. Thus, the purpose of this study is to verify the dimensions of the service quality of ocean passenger terminal. Based on a survey of 260 customers in port of Busan and Inchon, terminal service quality's five main dimensions have been checked regarding their fit with the use of Confirmatory Factor Analysis. Empirical results support that this is a valid instrument for measuring service quality of a ocean passenger terminal. The interactive sequence of computing Cronbach's alpha, corrected item-to-total correlation, and factor analysis was repeated a few times and resulted in a final set of 19 items representing five distinct dimensions-tangibles, responsiveness, knowledge, reliability, and accessibility. This finding provides the more appropriate instrument to evaluate the customers perception as well as to measure the service quality of ocean passenger terminal.

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Facile Synthesis of In2S3 Modified Ag3PO4 Nanocomposites with Improved Photoelectrochemical Properties and Stabilities

  • Zeng, Yi-Kai;Bo, Shenyu;Wang, Jun-hui;Cui, Bin;Gu, Hao;Zhu, Lei;Oh, Won-Chun
    • Korean Journal of Materials Research
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    • v.30 no.11
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    • pp.601-608
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    • 2020
  • In this work, Ag3PO4/In2S3 nanocomposites with low loading of In2S3 (5-15 wt %) are fabricated by two step chemical precipitation approach. The microstructure, composition and improved photoelectrochemical properties of the as-prepared composites are studied by X-ray diffraction pattern (XRD), field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), photocurrent density, EIS and amperometric i-t curve analysis. It is found that most of In2S3 nanoparticles are deposited on the surfaces of Ag3PO4. The as-prepared Ag3PO4/In2S3 composite (10 wt%) is selected and investigated by SEM and TEM, which exhibits special morphology consisting of lager size substrate (Ag3PO4), particles and some nanosheets (In2S3). The introduction of In2S3 is effective at improving the charge separation and transfer efficiency of Ag3PO4/In2S3, resulting in an enhancement of photoelectric behavior. The origin of the enhanced photoelectrochemical activity of the In2S3-modified Ag3PO4 may be due to the improved charge separation, photocurrent stability and oriented electrons transport pathways in environment and energy applications.

Photosynthetic Responses of Populus alba×glandulosa to Elevated CO2 Concentration and Air Temperature (CO2 농도 및 기온 상승에 대한 현사시나무의 광합성 반응)

  • Lee, Solji;Oh, Chang-Young;Han, Sim-Hee;Kim, Ki Woo;Kim, Pan-Gi
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.16 no.1
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    • pp.22-28
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    • 2014
  • This study was conducted to investigate the photosynthetic characters of Populus alba${\times}$glandulosa cuttings in response to elevated $CO_2$ concentration and air temperature for selecting tree species adaptive to climate change. The cuttings were grown in environment controlled growth chambers with two combinations of $CO_2$ concentration and air temperature conditions: (i) $22^{\circ}C$ + $CO_2$ 380 ${\mu}mol$ $mol^{-1}$ (control) and (ii) $27^{\circ}C$ + $CO_2$ 770 ${\mu}mol$ $mol^{-1}$ (elevated) for almost three months. The cuttings under the elevated treatment showed reduced tree height and photosynthetic pigment contents such as chlorophyll and carotenoid. In particular, the elevated treatment resulted in a marked reduction in the chlorophyll a closely associated with $CO_2$ fixative reaction system. Different levels of reduction in photosynthetic characters were found under the elevated treatment. A decrease was noted in photochemical reaction system parameters: net apparent quantum yield (7%) and photosynthetic electron transport rate (14%). Moreover, a significant reduction was obvious in $CO_2$ fixative reaction system parameters: carboxylation efficiency (52%) and ribulose-1,5-bisphosphate(RuBP) regeneration rate (24%). These results suggest that the low level of photosynthetic capacity may be attributed to the decreased $CO_2$ fixative reaction system rather than photochemical reaction system.

Railway Governance and Power Structure in China

  • Lee, Jinjing
    • International Journal of Railway
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    • v.1 no.4
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    • pp.129-133
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    • 2008
  • Over the last $15{\sim}20$years, many countries have adopted policies of railway privatization to keep up with increasing competition from road and air transport. Although each country and case has its own history, market characteristics, political context as well as administrative process, railway privatizations (including railway restructure, concession etc.) in the west usually are accompanied with the establishment of new regulatory regimes. Therefore, railway governance has been innovating towards an interaction of government, regulator, industry bodies, user groups, trade unions and other interested groups within the regulatory framework. However, it is not the case in China. Although China had seen a partial privatization in some branch lines and is experiencing a much larger-scale privatization by establishing joint-ventures to build and operate high-speed passenger lines and implementing an asset-based securitization program, administrative control still occupies absolutely dominant position in the railway governance in China. Ministry of Railway (MOR) acts as the administrator, operator as well as regulator. There is no national policy that clearly positions railway in the transportation network and clarifies the role of government in railway development. There is also little participation from interested groups in the railway policy making, pricing, service standard or safety matter. Railway in China is solely governed by the mere executive agency. Efficiency-focused economic perspective explanation is far from satisfaction. A wider research perspective from political and social regime is of great potential to better explain and solve the problem. In the west, separation and constrains of power had long been established as a fundamental rule. In addition to internal separation of political power(legislation, execution and jurisdiction), rise of corporation in the 19th century and association revolution in the 20th century greatly fostered the growth of economic and social power. Therefore, political, social and economic organizations cooperate and compete with each other, which leads to a balanced and resonable power structure. While in China, political power, mainly party-controlled administrative power has been keeping a dominated position since the time of plan economy. Although the economic reform promoted the growth of economic power of enterprises, it is still not strong enough to compete with political power. Furthermore, under rigid political control, social organizations usually are affiliated to government, independent social power is still too weak to function. So, duo to the limited and slow reform in political and social regime in China, there is an unbalanced power structure within which political power is dominant, economic power expanding while social power still absent. Totally different power structure in China determines the fundamental institutional environment of her railway privatization and governance. It is expected that the exploration of who act behind railway governance and their acting strength (a power theory) will present us a better picture of railway governance as a relevant transportation mode. The paper first examines the railway governance in China and preliminarily establishes a linkage between railway governance and its fundamental institutional environment, i.e. power structure in a specific country. Secondly, the reason why there is no national policy in China is explored in the view of political power. In China, legislative power is more symbolic while party-controlled administrative power dominates political process and plays a fundamental role in Chinese railway governance. And then, in the part three railway finance reform is analyzed in the view of economic power, esp. the relationship of political power and economic power.

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A Study on the Improvement of Item for Discrimination Increasing in Post Evaluation of Public Building Construction Project (공공건축공사 사후평가 변별력 향상을 위한 항목개선 연구)

  • Yoon, Tai-Hyong;Lee, Soo-Yong
    • Korean Journal of Construction Engineering and Management
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    • v.12 no.2
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    • pp.21-31
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    • 2011
  • The Ministry of Land, Transport & Maritime Affairs(former-The Ministry of Construction and Transportation)establish & promulgated the guide line of The Law of Post Evaluation on May 10, 2001(Article 58824-318) to public construction project under the Operation Law of Construction Engineering Management the 18 clause of Article 38 in order to induce & collect useful data about construction project when plan new similar project in the future about the initial planning phase, former and past accomplished businesses to construction works, results, efficiency, effectiveness. Ever since The Ministry revised 5 times, the former contents are composed for SOC, big volume civil project, and revised contents Article 2010-14(Jan 15, 2010) included some architectural project, but that was not definite the evaluation contents, direction & objective standard. So evaluation index implements are ambiguous about accomplished project. This research arranged the correctness evaluation indicators, criterions for decide the grades in order to helpful informations for similar architectural project in the future.

The Evaluation of Artificial Lung Using Blood Substitutes (대체혈액을 이용한 인공폐의 평가에 관한 연구)

  • Kim K.B.;Hong S C.;Kim M.H.;Jheong G.R.;Lee S.C.
    • Journal of Biomedical Engineering Research
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    • v.21 no.3 s.61
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    • pp.311-320
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    • 2000
  • In this paper a newly designed oxygenator module was used to perform the experiments for pressure drop and oxygen transport in order to evaluate the efficiency of the artificial lung. Also, distilled water. sodium sulfite solutions used in this experiment were evaluated for the performance of other artificial lungs. Substituted bloods have many advantages over whole blood in studying pressure drop and oxygen uptake. They are relatively inexpensive, and require fewer variables to be controlled. Furthermore, deoxygenation is not necessary when those solutions are used. In addition to these advantages. assays and interpretation of the experimental results are relatively easy. In the case of using the sodium sulfite solution having the same oxygen partial pressure as whole blood. the oxygen transfer rate of the sodium sulfite solution was basically same as that of whole blood. It was concluded in evaluating the function of artificial lungs that the sodium sulfite solution was suited for measuring oxygen transfer rate. In our module, artificial blood was flowed into the outside of hollow fiber membrane. The artificial lung created in this experiment showed that pressure drop was reduced to $1/3\~1/6$ of that compared to the inside-flow case.

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Evaluation of Street Tree Rootage by Transplanting Methods - Photochemical Response Analysis of Different Cultivation for Sorbus alnifolia - (가로수의 이식방법에 따른 수목 활착 평가 - 재배방법별 팥배나무의 광화학적 반응 해석 -)

  • Yoo, Sung Young;Park, So Hyun;Park, Chung In;Kim, Tae Jin
    • Journal of the Korean Institute of Landscape Architecture
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    • v.43 no.1
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    • pp.132-138
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    • 2015
  • Trees, cultivated in containers, are appropriate in soil deformation such as road sites with cutting and filling. This study tested the effectiveness of trees produced in containers for early rootage in street tree transplantation. For the study, Korean Mountain Ashes(Sorbus alnifolia) were used for experimental groups. The groups were categorized into three categories: trees cultivated in containers with mulching treatment(group A), trees cultivated outdoors with mulching treatment (group B), and trees cultivated in containers with weeding treatment(group C). Each group consisted of ten trees of the same size and transplanted to the experimental site. In order to compare each group's rootage, the study was carried out with the chlorophyll fluorescence method by the analysis of photochemical reaction. As a result of the study, group B had the lowest the maximum fluorescence amount(P). The amount of fluorescence increased by OJ transition of the process, and appeared to reduce the photosystem II electron transport efficiency. In photosystem II, electron transfer energy flux through photosystem I(RE1o/RC, RE1o/CS) was also reduced by more than 20% in group B. These results may imply that transplantation of container-cultivated trees with mulching treatment provides the most rapid rootage among the groups. The weeding treatment is also more effective than mulching treatment for rapid rootage of street trees.

The Fundamental Studies and Development of Modified Electrothermal Vaporization Hollow Cathode Glow Discharge Cell (개선된 전열증기화 속빈음극관 글로우 방전셀의 기초연구 및 개발)

  • Lee, Seong-Hun;Cho, Won-Bo;Jeong, Jong-Pil;Choi, Woo-Chang;Kim, Kyu-Whan;Woo, Jeong-Su;Lee, Chang-Su;Kang, Dong-Hyun;Lee, Sang-Chun
    • Analytical Science and Technology
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    • v.15 no.6
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    • pp.514-520
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    • 2002
  • The electrothermal vaporization (ETV) hollow cathode glow discharge atomic emission spectrometer for analysis of liquid sample has been developed and characterized. This system has improved the sample introduction method of electrothermal vaporization and the hollow cathode glow discharge. The sample introduction method was possible to provide high analyte transport efficiency to the plasma by helix coil made of tungsten material. In addition, small volume samples (<$30{\mu}{\ell}$) could be used. The system has glow discharge cell with special design for improvement of precision. The effect of discharge parameters such as discharge power, gas flow rate has been studied to find optimum condition. The emitted light was effectively carried into detector by fiber optic cable in UV region. The calibration curve of Pb, Cd were obtained with 3 samples.

A study on strategies to attract container cargoes in Incheon - with the case of container O/D analysis ­ (인천항 컨테이너 화물 유치방안에 대한 연구 -컨테이너 OD분석을 중심으로-)

  • Chung Tae-Won;Choi Sae-Kyung
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2006.06b
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    • pp.289-299
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    • 2006
  • This paper aims to provide strategies to attract container cargoes for the Incheon port by analysing O/D of the container cargoes with the year-2004 export and import data from. The Korean customs service. O/D analysis was carried out with establishing optimal zones, which are defined as City, Gun, Gu(Korean administrative districts) to which the export-import service can be provided from a certain port with minimized freight(or transport) cost and stevedoring fee. For the Incheon port, 35 administrative districts including Seoul and Incheon in Kyunggi-Do and Kangwon-Do are recognized as the optimal zones, and approximately 25.50% of around 2.02-million-TEU per year of the cargoes from the woes are exported and imported through the pan. The strategies to attract container cargoes was suggested by comparing the Incheon port to supposed-competitive pons. The Busan portn(64.89%), Guangyang port(4.46%) and Pyeongtaeck port(3.35%) are supposed as the competitive pons which have a large proportion of handling the cargoes from the optimal zones. When comparing the Incheon port to these ports, The Incheon pan requires a distinctive cost strategy, providing incentives to attract shipping companies and cargoes, improving efficiency related to loading-unloading at the port, and reinforcing Feeder-Network and advertisements about cost-saving to the shippers(the owners of goods) in the national capital region. Consequently, the mentioned requirements are suggested as the strategies to attract cargoes for the Incheon port.

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Optical Monte Carlo Simulation on Spatial Resolution of Phosphor Coupled X-ray Imaging Detector (형광체 결합형 X선 영상검출기의 공간 해상력 몬테카를로 시뮬레이션)

  • Kang, Sang-Sik;Kim, So-Yeong;Shin, Jung-Wook;Heo, Sung-Wook;Kim, Jae-Hyung;Nam, Sang-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.328-328
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    • 2007
  • Large area matrix-addressed image detectors are a recent technology for x-ray imaging with medical diagnostic and other applications. The imaging properties of x-ray pixel detectors depend on the quantum efficiency of x-rays, the generated signal of each x-ray photon and the distribution of the generated signal between pixels. In a phosphor coated detector the light signal is generated by electrons captured in the phosphor screen. In our study we simulated the lateral spread distributions for phosphor coupled detector by Monte Carlo simulations. Most simulations of such detectors simplify the setup by only taking the conversion layer into account neglecting behind. The Monte Carlo code MCNPX has been used to simulate the complete interaction and subsequent charge transport of x-ray radiation. This has allowed the analysis of charge sharing between pixel elements as an important limited factor of digital x-ray imaging system. The parameters are determined by lateral distribution of x-ray photons and x-ray induced electrons. The primary purpose of this study was to develop a design tool for the evaluation of geometry factor in the phosphor coupled optical imaging detector. In order to evaluate the spatial resolution for different phosphor material, phosphor geometry we have developed a simulation code. The developed code calculates the energy absorption and spatial distribution based on both the signal from the scintillating layer and the signal from direct detection of x-ray in the detector. We show that internal scattering contributes to the so-called spatial resolution drop of the image detector. Results from the simulation of spatial distribution in a phosphor pixel detector are presented. The spatial resolution can be increased by optimizing pixel size and phosphor thickness.

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