• 대한교통학회:학술대회논문집
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• 대한교통학회 1998년도 Proceedings The 4th International Transport Symposium
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• pp.59-64
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• 1998

The Railway Station for Passenger Transport is an important part of the railway transport business. It is also the main changing hub in the comprehensive traffic system in cities. This passage, taking Shanghai Railway Station as an example, deals with the modem management of the railway station for passenger transport and the double-ring quality system of the setting-up of the three flows(the passenger, the train and the luggage and the two operation procedures dispatch and arrival)

• 한국환경과학회지
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• 제3권1호
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• pp.11-16
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• 1994

Generally, it is difficult to predict water quality in a tidal river, because tidal flows make the transport phenomena more complicated. The purpose of this study is to clarify long-term mass transport in a tidal river through suggestion of simulation model. A simulation model based on a Lagrangian coordinate system, which has the advantage reducing numerical dispersion, was used to calculate changes in concentration of chlorides. Several field surveys were conducted to verify calculated results. Concludingly, long-term behavior of mas transport in a tidal river can be represented using the model.

• Animal Bioscience
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• 제35권7호
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• pp.1039-1047
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• 2022

Objective: The purpose of this study is to determine the optimal time of transportation of floor-feed and scatter-feed broilers. Methods: Eighty healthy Arbor Acres (AA) broilers (21-day-old, 624.4 g, male, standard error = 6.65) were selected and randomly divided into two experimental groups (floor-feed and scatter-feed), then fed for three weeks. The experiment comprised a 2×4 factorial design with 2 feed patterns (floor-feed and scatter-feed) and 4 transport periods (2, 3, 4, and 5 h), and 4 replicates of 5 broilers (54-day-old, 2243 g, standard error = 46.65) was used to compare weight loss, meat quality and behavior index of different groups. Results: It appeared that drip loss, meat color and resting behavior of experimental broilers changed as length of transportation (p<0.05), however, weight loss and pH were not significantly transformed (p>0.05). Compared with floor-feed group, broilers in scatter-feed group had lower pH at 24 hours (3 h) and different behavioral indicators (p<0.05). Especially indicators after 3 h transportation, there were obvious differences between the two feeding modes in the behavior reaction of stress events before slaughter with different transport duration (p<0.05). The fluctuation of data on resting behavior with scatter-feed was significantly higher than that of floor-feed broilers. There was no interaction between transport time and different feeding methods for index tested of our experiment (p>0.05). Conclusion: Comprehensive analysis showed that the maximum transport duration of floor-feed and scatter-feed broilers should not exceed 3 h, and scatter-feed broilers were more likely prone to fear.

• 한국물환경학회지
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• 제23권6호
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• pp.872-880
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• 2007

For effective management of sediment-related diffuse pollution, it is of utmost importance to estimate spatial variation of sediment transport processes within a catchment. A mathematical model can play a critical role in estimating sediment transport processes at the catchment scale provided that the model structure is appropriate for representing major sediment transport processes of the catchment of interest. This paper introduces a distributed catchment model River Basin Water Quality Simulator (RBWQS) and presents some results of its application to a small rural catchment in Korea. The model has been calibrated and validated for a wet period using hourly hydrographs and sediment concentrations observed at the catchment outlet. Based on the model simulation results, the spatial variation of sediment transport processes across the catchment and the effects of paddy fields and small reservoirs on hydrology and sediment transport have been analyzed at the catchment scale.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 춘계종합학술대회
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• pp.378-382
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• 2001

인터넷 방송 등의 서비스를 제공하는 서버 시스템 등에서 사용자 수가 증가함에 따라 서비스 질이 저하된다거나 네트워크의 폭주로 인하여 실시간성 상실 및 데이터 손실이 발생할 수 있다. 또한. 인터넷 방송 등과 같이 네트워크를 통해서 압축 부호화된 영상이나 음성 데이터를 전송하는 경우, 일반적인 multicast 방식으로는 신뢰성 있는 데이터 전송을 보장할 수 없다는 문제점이 있다. 이를 극복하기 위하여 사용자 수의 증가에 대하여 서버가 크게 영향을 받지 않도록 하는 방법과, 다양한 사용자의 네트워크 상황을 고려하는 지능적인 데이터 송신 기술이 요구된다. 본 논문에서는 다수 이용자를 지원하는 인터넷 방송과 같은 응용에서 신뢰성있는 실시간 영상 및 음성 데이터 전달을 위하여, reliable multicast를 사용하여 전송 오류가 없도록 하고, 네트워크 환경에 따른 사용자별 adaptive encoding을 통해 다양한 네트워크 환경에 동적으로 적응하여 서비스의 질을 향상시키며, 비슷한 접속 속도의 사용자들을 그룹화하여 사용자 수의 증가에 대한 서버의 부하를 줄이는 서버 구현 방법을 제안한다.

• Journal of Biosystems Engineering
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• 제40권4호
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• pp.409-416
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• 2015

Purpose: This study evaluates a new banana bulk packaging method under the real transport conditions of Sri Lanka. Methods: A field evaluation of optimized 8-mm thick Styrofoam sheets used as the cushioning material was applied. A trial transport was conducted from Thambuttegama to Colombo using a medium-sized open truck, with banana leaves as the control material. Data were recorded at the farmer, transporter, retailer, and consumer stages of the supply chain. Mechanical damage, physiological loss in weight, fruit firmness, total soluble solids, ripeness index, visual quality ratings, and the physical damage index of the bananas were measured at each stage. A cost-benefit analysis was also conducted for both packaging methods. Results: The 8-mm styrofoam sheets significantly reduced (p < 0.05) the mechanical damage from 26.3% to 12.9% compared to the conventional method for long-distance transport, and the physiological loss in weight showed a decrease of 2.88%. The loss of firmness of the fruits followed a simmilar pattern for both methods until reaching the retailer, but at the consumer was significantly higher (p < 0.05) for the control. However, the physical damage index at the retail stage for the control showed symptoms of physical injury, whereas the bananas transported using the cushioning materials exhibited only minor symptoms. Further, the visual quality of the fruits after transport from the farmer to the consumer was preserved, which is one of the main factors affecting consumer preference and retail price. The proposed method increases the profit margin by 51.2% for Embul bananas owing to the reduced postharvest losses. Conclusion: The 8-mm thick Styrofoam sheets reduced the physical damage to the bananas, with the quality parameters maintained at the prefered level. Moreover, profits may be increased.

• 대한교통학회지
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• 제35권1호
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• pp.37-49
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• 2017

본 연구에서는 도로이동오염원을 대상으로 추진하는 교통환경정책의 대기질 개선효과 분석 방법론을 제시하였으며, 해당 방법론은 정책 추진에 따른 도로이동오염원의 통행량과 대기오염물질 배출량 변화, 대기오염물질의 공간적 확산과 이로 인한 노출인구의 건강영향을 순차적으로 고려한다. 특히 도로이동오염원의 통행량 변화는 정책 효과와 직접적인 연관이 있기 때문에 대기질 개선효과 분석시 반드시 고려되어야 하며, 본 연구에서는 교통수요모형 기반의 상향식 방법을 적용하여 기존 하향식 방법 대비 정책 추진에 따른 통행자의 통행행태 변화를 상세하게 반영하고자 하였다. 정책 시나리오 분석을 통하여 본 연구에서 제시한 분석 방법론의 활용가능성을 검토하였으며, 통행자의 통행행태 변화가 예상되는 정책의 대기질 개선효과 분석은 본 연구의 분석 방법론 적용이 필요한 것으로 판단된다.

• 한국대기환경학회지
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• 제34권2호
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• pp.294-305
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• 2018

Quantitative assessment on the impact from North Korean emissions to surface particulate matter(PM) concentration in the Seoul Metropolitan Area (SMA), South Korea is conducted using a 3-dimensional chemistry transport model. Transboundary transport of air pollutants and their precursors are important to understand regional air quality in East Asian countries. As North Korea locates in the middle of main transport pathways of Chinese pollutants, quantifiable estimation of its impact is essential for policy making in South Korean air quality management. In this study, the Community Multiscale Air Quality Modeling System is utilized to simulate regional air quality and its sensitivity, using the Comprehensive Regional Emissions inventory for Atmospheric Transport Experiment 2015 and the Clean Air Policy Support System 2013 emissions inventories for North and South Korea, respectively. Contributions were estimated by a brute force method, perturbing 50% of North and South Korean emissions. Simulations demonstrate that North Korean emissions contribute $3.89{\mu}g/m^3$ of annual surface PM concentrations in the SMA, which accounts 14.7% of the region's average. Impacts are dominant in nitrate and organic carbon (OC) concentrations, attributing almost 40% of SMA OC concentration during January and February. Clear seasonal variations are also found in North Korean emissions contribution to South Korea (and vice versa) due to seasonal characteristics of synoptic weather, especially by the change of seasonal flow patterns.

• Structural Monitoring and Maintenance
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• 제7권1호
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• pp.43-58
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• 2020

Pile foundations of existing bridges lie in soil and water environment for long term and endure relatively heavy vertical loads, thus prone to damages, especially after stricken by external forces, such as earthquake, collision, soil heap load and etc., and the piles may be injured to certain degrees as well. There is a relatively complete technical system for quality inspection of new bridge pile foundations without structures on the top. However, there is no mature technical standard in the engineering community for the non-destructive testing technology specific to the existing bridge pile foundations. The quality of bridge pile foundations has always been a major problem that plagues bridge maintenance. On the basis of many years' experiences in test engineering and theoretical studies, this study developed a new type of detection technology and equipment for the existing bridge piles.

• 환경위생공학
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• 제8권1호
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• pp.49-67
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• 1993

Rapid economic development and increase of energy consumption in east Asia including China, Korea and Japan has arisen a concern in air pollution problems in local and regional scale. Specially, China is accomplishing a success in continuous economic growth, while increasing energy consumption has caused a load to air quality because major energy source is coal which is relatively unfavorable in terms of air pollution. In this article, discussions have been given with the purpose of gaining some insight into the situation of air pollutant sources, air quality in China and transboundary transport of air pollutants in this area. Very limited information has caused insufficient survey, however, regional cooperation in environmental conservation may hopefully improve the air quality in this area.