• International Journal of Railway
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• 제5권1호
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• pp.29-37
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• 2012

The rail sector, despite its potential for curtailing the present chaotic transport situation in Lagos, remains inefficient and underutilized. In spite of past initiatives and the current attempt by the Lagos State Government to provide a mass transit rail service in Lagos, the share of rail mode in the transport sector has not been encouraging and the railway plays an insignificant role in urban mass transit in Lagos at present. This paper sets out to assess the usage of the Lagos mass transit trains. Hence, the paper determines the passenger traffic flow along the rail route in Lagos and the number of passengers carried between 2000 and 2009 by the Lagos Mass Transit Trains (LMTT) with a view to assessing the usage of the present LMTT. This paper also discusses the historical development of Nigerian railway and describes rail transport in Lagos. Data were obtained through secondary sources coupled with review of literature. The result of this study shows that for a period of 10 years (2000-2009), Lagos mass transit trains carried a total of 9,870,101 passengers, which gives an average of 987,010 passengers annually. This suggests that the service of the Lagos mass transit train is grossly underutilized. However, LMTT contributes enormously to NRC by carrying 68.5% of the total passenger traffic of NRC between 2000 and 2009. In terms of passenger traffic flow along the route of LMTT, for a period of 1 year, Agbado station recorded the largest number of passengers (393,811), followed by Ijoko (163,652) and Iddo (120,787), while Iganmu station has the lowest number of rail commuters (16,919). This study also discloses that the major commodities hauled by Lagos district of NRC from Lagos to the northern parts of the country in 2007 are Cars, Cement, Billet and Wheat.

• 한국응급구조학회지
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• 제24권3호
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• pp.161-169
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• 2020

Purpose: This study aims to identify changes in patients' transport time and chief complaints visiting the emergency room via emergency medical services from the "pre-COVID-19 period" compared to the "COVID-19 early-stage period". Methods: This retrospective observational study analyzed the emergency medical services reports at two time periods defined by the COVID-19 virus outbreak in Korea. The study was conducted in Busan, the Republic of Korea, from January 19 through May 6, 2019. Results: The transfer time of patients transported during the "COVID-19 early-stage period" was significantly delayed compared to the "pre-COVID-19 period" (p<.05). We found a significant increase in transport time for patients complaining of respiratory infections compared to patients without symptoms (p<.05). During the "COVID-19 early-stage period", there was a significant increase in the number of patients with respiratory infections and patients complaining of general symptoms compared to the "COVID-19early-stage period" (p<.05). Conclusion: The spread of the COVID-19 virus infection delayed patient transport and increased the number of patients reporting respiratory infection symptoms. Emergency medical services will need administrative and economic support to transport the increased number of patients requiring services.

• 한국ITS학회 논문지
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• 제13권5호
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• pp.27-34
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• 2014

본 논문은 무선 채널을 노드에게 할당하여 보장하는 GTS 기반의 무선 센서 네트워크에서 다수의 노드가 같은 채널을 공유할 때, 충돌이 발생하는 것을 최대로 억제하기 위한 방안을 제시한다. 무선 자원이 충분하지 않은 조건에서 다수의 노드에게 특정 채널을 같이 할당하고, 할당한 채널을 노드들이 공유하면서 데이터를 전송한다. 데이터 전송 시, 한개 이상의 노드들이 채널을 이용하면 충돌이 발생한다. 이러한 충돌을 효과적으로 줄이기 위해, 부모가 자식 노드들에게 백오프 값들을 지정하고, 그래도 충돌이 생기는 경우, 백오프 값 변경을 시도하여 충돌을 방지한다. 제안 방안을 시뮬레이션을 통해 제안 방안이 효과적으로 백오프 값을 조절하여 충돌이 많이 감소함을 확인할 수 있었다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 추계학술대회
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• pp.69-73
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• 2000

We systematically analyze the influence of fracture junction, solute transfer characteristics on transport patterns in discrete, two-dimensional fracture network models. Regular lattices and random fracture networks with power-law length distributions are considered in conjunction with particle tracking methods. Solute transfer probabilities at fracture junctions are determined from analytical considerations and from simple complete mixing and streamline routing models. For regular fracture networks, mixing conditions at fracture junctions are always dominated by either complete mixing or streamline routing end member cases. Moreover bulk transport properties such as the spreading and the dilution of solute are highly sensitive to the mixing rule. However in power-law length networks there is no significant difference in bulk transport properties, as calculated by assuming either of the two extreme mixing rules. This apparent discrepancy between the effects of mixing properties at fracture junctions in regular and random fracture networks is explained by the statistics of the coordination number and of the flow conditions at fracture intersections. We suggest that the influence of mixing rules on bulk solute transport could be important in systematic orthogonal fracture networks but insignificant in random networks.

• International Journal of Naval Architecture and Ocean Engineering
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• 제5권2호
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• pp.277-286
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• 2013

Cross-shore sediment transport is very important factor in the design of coastal structures, and the beach profile is mainly affected by a number of parameters, such as wave height and period, beach slope, and the material properties of the bed. In this study cross-shore sediment movement was investigated using a physical model and various offshore bar geometric parameters were determined by the resultant erosion profile. The experiments on cross- shore sediment transport carried out in a laboratory wave channel for initial base slopes of 1/8, 1/10 and 1/15. Using the regular waves with different deep-water wave steepness generated by a pedal-type wave generator, the geometrical of sediment transport rate and considerable characteristics of beach profiles under storm conditions and bar parameters affecting on-off shore sediment transport are investigated for the beach materials with the medium diameter of $d_{50}$=0.25, 0.32, 0.45, 0.62 and 0.80 mm. Non-dimensional equations were obtained by using linear and non-linear regression methods through the experimental data and were compared with previously developed equations in the literature. The results have shown that the experimental data fitted well to the proposed equations with respect to the previously developed equations.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 동계학술발표대회 논문집
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• pp.317-322
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• 2005

This study is aimed to analyze the effects of heat pipe shape on the heat transfer in solar collector with a axial grooved heat pipe. In the design of a heat pipe. two of the most important criteria to be met are the operating temperature range and the maximum heat transport capacity, When the operating temperature range is known and the working fluid has been selected, the maximum heat transport capacity depends strongly on capillary pressure and liquid flow. The heat transport capacity of the heat pipe will depend on the geometry of the heat pipe, the wick structure. the vapor channel shape. groove number. cooling temperature. condenser length and pipe diameter. So various shapes are used for mathematical models of two-phase flow in grooved heat pipe. From the results. the adequate groove shape and scale are presented by considering the heat transport and capillary limitation.

• Membrane and Water Treatment
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• 제3권1호
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• pp.63-76
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• 2012

Mother liquid discharged from a salt-manufacturing plant was electrodialyzed at 25 and $40^{\circ}C$ in a continuous process integrated with $SO_4{^{2-}}$ ion low-permeable anion-exchange membranes to remove $Na_2SO_4$ and recover NaCl in the mother liquid. Performance of electrodialysis was evaluated by measuring ion concentration in a concentrated solution, permselectivity coefficient of $SO_4{^{2-}}$ ions against $Cl^-$ ions, current efficiency, cell voltage, energy consumption to obtain one ton of NaCl and membrane pair characteristics. The permselectivity coefficient of $SO_4{^{2-}}$ ions against $Cl^-$ ions was low enough particularly at $40^{\circ}C$ and $SO_4{^{2-}}$ transport across anion-exchange membranes was prevented successfully. Applying the overall mass transport equation, $Cl^-$ ion and $SO_4{^{2-}}$ ion transport across anion-exchange membranes is evaluated. $SO_4{^{2-}}$ ion transport number is decreased due to the decrease of electro-migration of $SO_4{^{2-}}$ ions across the anion-exchange membranes. $SO_4{^{2-}}$ ion concentration in desalting cells becomes higher than that in concentration cells and $SO_4{^{2-}}$ ion diffusion is accelerated across the anion-exchange membranes from desalting cells toward concentrating cells.

• Journal of the Korean Physical Society
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• 제73권12호
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• pp.1855-1862
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• 2018

A reliable set of low-energy electron collision cross sections for the triethoxysilane (TRIES) molecule was derived based on the measured electron transport coefficients for a pure TRIES molecule by using an electron swarm method and a two-term approximation of the Boltzmann equation. The electron transport coefficients calculated using the derived set are in good agreement with experimental value over a wide range of E/N values (ratio of the electric field E to the neutral number density N). The present electron collision cross section set for the TRIES molecule, therefore, is the most reliable so far for plasma discharges and for materials processing using the TRIES molecule. Moreover, the electron transport coefficients for the TRIES-Ar and the $TRIES-O_2$ mixtures were also calculated and analyzed over a wide range of E/N for the first time.

• 한국응급구조학회지
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• 제12권1호
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• pp.5-15
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• 2008

Purpose : Centering on users(patients) who are offered the patient transport service by the emergency medical service system in our country, the use and satisfaction are analyzed with the transport service in 119 Emergency Medical Service System and Private transport agent. Results : 1. As for personnel in ambulance cars, 119 emergency staff showed a higher boarding rate of the first-class emergency medical technicians than private transportation centers : 48.4% and 17.7%, respectively. 2. Private transportation centers showed higher user satisfaction with transportation service than 119 emergency staff, which was not statistically significant. 3. As for the case that needs to receive the transport service in the future, the ratio with the will to use 119 Emergency Medical Service System(70.9%) was indicated to be much higher than the ratio of the private transport agent(29.1%). Suggestions : First, Centers transporting first-aid patients should essentially secure a sufficient number of first-class emergency medical technicians as professional emergency medical staff to reinforce qualitative improvement in emergency medical service. Second, It is necessary to establish a systematic monitoring system and develop educational programs in order to enhance satisfaction with the use of 119 emergency staff. Third, the government or the local government needs to positively support and guide the private transport agent, which is in charge of the public medical service.

• 한국조사연구학회:학술대회논문집
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• 한국조사연구학회 2003년도 춘계학술발표대회
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• pp.59-68
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• 2003

통계청에서 실시하는 사업체관련 통계조사들 중 운수업통계조사는 국내의 모든 운수업체를 대상으로 종사자수, 급여, 수입, 비용 및 유형고정자산 등 운수업부문의 경영활동실태와 구조를 파악하기 위해 매년 실시하는 조사이다. 이 조사에서 얻어진 결과들은 국가정책수립과 평가를 위한 기초자료로서 뿐만 아니라 기업경영계획수립과 학술연구 등에 널리 활용되어지고 있다. 본 논문에서는 올해 실시한 운수업통계조사의 표본설계에 대해 설명하고, 아울러 통계청에서 실시하고 있는 표본사업체들의 관리에 대해 알아보고자 한다.