• 유통과학연구
• /
• 제12권2호
• /
• pp.27-37
• /
• 2014

Purpose - As economic activities between different countries have rapidly spread in a world of free trade, it is inevitable that a large volume of cargo will be carried between countries. It is natural, then, that CO2 emissions and other environmental pollutions have followed, which exposes people and society to serious environmental problems and social costs, and so on. Therefore, the need to understand logistics is not only a matter of transportation but also an environmentally oriented matter. The purpose of this study is to look at some lessons and implications from the European case in terms of green logistics matters. Research design, data, and methodology - In order to look into this matter, first, it has to be established that some cargo transport volumes using different transportation modes have clearly declined because of previous economic recessions. Some transport policies produced by the European Union (EU) are based in a long history of struggling to cope with transport matters in European countries. In its recent transport policies, the EU has provided greener transportation alternatives, realizing that pollution matters affect the European transport market. This study tries to determine what policies the EU has implemented to deal with green logistics matters. This study concentrates in particular on the Marco Polo program in the EU. Results - This study found that the EU seems to consider these kinds of matters, that is, transport and the environment in the context of green logistics. The EU launched some policy instruments to solve this matter relatively earlier than other countries and reviewed them as necessary. In order to make these policy tools work, the EU provided PACT for combined transport, and then the Marco Polo I and II European transport white paper packages. These European policies deal with green logistics matters in two ways. First, some restrictions have been imposed, especially taxation, and so on. Transport subsidies are also powerful means of handling green logistics matters in Europe. Along with these two means of dealing with transport and the environment, the EU eventually targeted integration of different transport modes. Instead of employing only a single transport instrument mode to deliver the cargo to be carried, such as trucking, rail, ocean-going carrier, flight, or inland waterway transport, the EU has proposed that combining transport modes is the best alternative for transport and the environment. That is, the EU is pursuing the adoption of multimodalism as an answer to the green logistics challenge as it provides a more cost efficient and more productive means of transport. Conclusions - In conclusion, multimodal transport should be considered when applying green logistics, as it can provide an alternative way to achieve transport and environmental solutions together at the present time. Two methods can be used to encourage multimodal transport: restrictions and subsidies. These are the lessons and implications from European green logistics policies.

• 한국ITS학회 논문지
• /
• 제20권6호
• /
• pp.55-65
• /
• 2021

코로나 19가 국내에서 2020년 1월 첫 확진자가 발생하며 현재까지 pandemic 상황이 지속하고 있다. 전례 없는 상황에 코로나 19는 교통 분야에도 영향을 끼쳤으며 시민들의 생활패턴변화로 교통량의 변화 및 대중교통 이용변화에 적절한 대응 방안이 존재하지 않았다. 현재 각 지자체에서는 pandemic 상황에 대한 질병 대책 방안은 별도로 수립하고 있지 않다. 향후 교통분야 질병 대책 방안 수립을 위해 교통량 및 대중교통 이용 건수를 분석하였으며 예측모형 개발을 위해 코로나 19 현황과 상관도 분석을 수행하였다. 분석 결과 교통량은 감소하였지만 개인 교통수단의 증가로 교통량 감소량은 대중교통 이용 건수에 비해 감소율이 낮다. 또한 대중교통 이용 현황은 초기에는 확진자 수에 영향을 받았지만 시간이 지남에 따라 확진자 수 보다는 사망자 수와 치명률에 더욱 민감하게 반응하는 것으로 분석되었다.

• Journal of Ecology and Environment
• /
• 제31권1호
• /
• pp.45-67
• /
• 2008

Ocean climate variables ($1900{\sim}2005$), time series of catches ($1910{\sim}2005$) and body size data were used to assess the year-to-year and decadal scale fluctuations in abundance of the fish populations (Japanese sardine, anchovy, jack mackerel, chub mackerel, Pacific saury and common squid) that have spawning grounds in the East China Sea and its adjacent regions. A negative correlation between the abundance of pelagic fishes (e.g. jack mackerel) in the Tsushima Warm Current (TWC) region and the Kuroshio-Oyashio Current (KOC) region was attributed to the climatic modulation of larval transport and recruitment, which depends on the winter monsoon-induced drift, current systems, and spawning season and site. The changes in abundance and alternation of dominant fish populations in the two regions in the 1930s, 1970s, and late 1980s mirrored changes in the climate indices (ALPI, AOI and MOI). Oscillations in the decadal climate shifts between the two regions led to zonal differences in larval transport and recruitment, and hence differences in the abundance of the pelagic fish populations. During deep Aleutian Lows, as in the 1980s, larval transport from the East China Sea to the KOC region increases in association with the strong winter Asian monsoon, cool regime and increased volume transport of the Kuroshio Current systems, whereas during a weak Aleutian Low (as in the 1990s), larval transport to the TWC region increased in association with a weak winter Asian monsoon, a warm regime, and increased volume transport of the Tsushima current system. We postulate that the increased chub mackerel abundance in the TWC region and the decreased abundance in the KOC region in the 1990s are partly attributed to changes in recruitment and availability to the fishing fleets under the warm regime in the spawning and nursery grounds in the East China Sea in association with the quasi-steady state of mild winter monsoon in the 1990s. The fluctuations in chub mackerel and jack mackerel abundance are under the environment-dependant growth form, although the tropicalization was identified in the TWC region. The density-dependant growth form was found in Japanese sardine populations, but no tropicalization by fishing was identified in the long ($10{\sim}15$ year) periods of abundance despite their short ($3{\sim}4$ year) generation time, suggesting that the environment-dependant growth form drove the changes in abundance. Year-to-year and decadal scale variations in abundance and population structure of the Pacific saury responded to climate regime shifts (1976/1977, 1988/1989), suggesting that the fish is a key bio-indicators for changes in the ecosystem.

• 한국ITS학회 논문지
• /
• 제11권2호
• /
• pp.57-66
• /
• 2012

본 연구에서는 향후 국내 도입이 예상되는 버스 우선신호시스템의 도입시 발생하는 운영상 효과를 현장조사 자료를 기반으로 평가하여 제시하였다. 이를 위하여 시스템 도입 전후의 통행시간과 교통량을 측정하여, 차종별 개별 통행시간의 분포와 교통량, 그리고 통행시간의 변화를 분석하였다. 사전/사후 조사의 교통량 분석 결과, 승용차와 버스 모두 방향별로 약간의 교통량 변화가 나타났으나, 그 크기는 통행시간의 변화에 큰 영향을 미치지 않았다. 개별차량의 통행시간을 분석한 결과, 버스 우선신호제어 실시 후에 해당 구간의 승용차 및 버스의 통행시간 분포가 매우 개선되었다. 그리고 통행속도의 경우, 첨두와 비첨두 시간대 모두 주도로 방향의 버스 및 승용차의 통행속도가 증가하였다. 전체적으로 승용차 속도는 25.9 km/h에서 27.6 km/h로 약 6.5% 증가하였고, 버스는 19.2 km/h에서 21.3 km/h로 약 10.5% 속도가 증가하였다. 통계적 검증 결과 이러한 속도 변화는 95%신뢰수준에서 통계적으로 유의하였다. 본 연구결과는 향후 버스우선신호 관련 연구의 기초자료로 활용될 것으로 기대된다.

• 한국ITS학회 논문지
• /
• 제11권3호
• /
• pp.13-22
• /
• 2012

도로 설계를 위한 기본 교통량으로 이용되는 중방향 설계시간 교통량(directional design hourly volume, DDHV)은 교통 및 도로 부문에서 매우 중요한 요소이다. DDHV는 연평균 일교통량(annual average daily traffic, AADT)에 설계시간계수(K 계수)와 중방향계수(D계수)를 고려하여 산정된다. 그러나 K계수와 D계수는 연간 모든 시간 교통량을 관측해야 가능하기 때문에 사실상 불가능하며, 도로용량편람(KHCM)에서 제시하는 K계수와 D계수를 그대로 적용하는 경우가 일반적이다. 본 연구에서는 일반국도를 대상으로 신뢰성 높고 현실적으로 적용 가능한 DDHV 추정 모형을 개발하고자 하였다. 일반국도 상에 설치된 상시 교통량 조사장비에서 수집된 교통자료를 이용하여 DDHV 특성을 분석한 결과, DDHV와 AADT 간 강한 상관관계가 존재함을 확인하였다. 따라서 AADT를 이용한 DDHV 추정 모형을 개발하였으며, 기존 KHCM 방법에 비해 성능이 우수한 것으로 분석되었다.

• 대한교통학회지
• /
• 제14권1호
• /
• pp.81-99
• /
• 1996

This study aims to assess the potential competition among road, rail, and coastal transport under various scenarios concerning the future inland container transport systems in Pusan-KyungIn corridor. For this SP approaches are adopted to collect data from shippers and carriers, and multinomial logit models are estimated at disaggragate level. The results of the analysis indicate that the SP data are reliable, and that the mode choice models estimated are valid. The results also indicate that the most effective policy to divert the freight volume from road to other modes is to reduce freight rates for the railway, and is to transport time for the coastal water with improved reliability.

• Biomolecules & Therapeutics
• /
• 제14권1호
• /
• pp.45-49
• /
• 2006

The purpose of this study was to clarify the efflux transport system of choline from brain to blood across the blood-brain barrier (BBB) in rats using the brain efflux index (BEI) method. $[^3H]$Choline was micro-injected into parietal cortex area 2 (Par2) of the rat brain, and was eliminated from the brain with elimination halflife of 45 min. The BBB efflux clearance of $[^3H]$choline was about 124 mL/min/g brain, which was determined from combination of an elimination rate constant $(1.54X10^{-2}min^{-1})$ and the distribution volume in the brain (8.05 mL/g brain). The efflux of $[^3H]$choline was inhibited by unlabeled choline in a dose-dependent manner and was significantly inhibited by cationic substrates, such as hemicholinium-3 and tetraethylammonium (TEA). These results suggest that the BBB may act as an efflux pump for choline to reduce the excessive choline concentration in the brain interstitial fluid.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 춘계학술대회
• /
• pp.1195-1200
• /
• 2004

A fully coupled fluid flow, heat, and solute transport model was developed to investigate turbulent flow, solidification, and macrosegregation in a continuous casting process of steel slab with EMBR. Transport equations of mass, momentum, energy, and species for a binary iron-carbon alloy system were solved using a continuum model. The electromagnetic field was described by the Maxwell equations. A finite-volume method was employed to solve the conservation equations associated with appropriate boundary conditions. The effects of intensity of magnetic field and carbon segregation were investigated. The electromagnetic field reduces the velocity of molten flow in the mold and an increase in the percentage of C in steel results in a decrease of carbon segregation ratio.

• 한국안전학회지
• /
• 제4권1호
• /
• pp.15-24
• /
• 1989

The transport of Chromium(Vl) ion from waste water throughl the liquid surfactant membrane containing tri-n-octylamine as a carrier, was analyzed by a slab model and was investigated through experiments. For the experiment of membrane stability, concentrations of surfactant and liquid parafnn oil were analyzed. Extraction euperiments were carried out to observe the effect of system variables, such as stirring speed, concentration of carrier, and NaOH in internal aqueous phase, and concentrations of H$_2$SO$_4$and initial chromium(VI) ion in external aqueous phase at $25^{\circ}C$. It is concluded that the most stable formation of liquid membrane emulsion was obtained when surfactant concentration is above 3 wt. ％ and liquid parafnn oil concentration is 50 vol. ％. The transport of chromium(VI) ion in bacth extractor increased with increasing carrier concentration, the volume ratio of emulsion to external aqueous phases, and initial concentration of chromium(VI) ion under the optimum stirring speed of chromium(VI) ion below 2 ppm. The theoretical equation on the transport of chromium(Vl) ion agreed well with the experimental results.

• 한국항해항만학회지
• /
• 제35권4호
• /
• pp.343-349
• /
• 2011

The forecasting of container volume which is the basis of port logistics facilities expansion has a great influence on development of an port. Based on this importance, various previous studies have presented methodology on container volume forecasting. The results of many previous studies pointed out the limitations of future forecasting based on past container volume and emphasized that more various factors should be considered to compensate this. Taking notice of this point, this study forecasted future container volume by using ARIMA model, time series analysis and System Dynamics (SD) method, a dynamic analysis technique and performed the comparative review with the forecast of the Ministry of Land, Transport and Maritime affairs. Recently with rapid changes in economic and social environment, the non-linear change tendency for forecasting container traffic is presented as a new alternative to the country.