• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.17-28
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• 2008

Favorable policies for freight vehicles (i.e., trucks), such as exclusive "Truck-ways," have been proposed, and at the same time restricted policies for freight vehicles have been suggested because transportation of goods by truck aggravates traffic congestion and environmental conditions in urban areas. This study discusses the limitations of assessment processes for freight vehicle route management systems which have been carried out from limited perspectives such as physical distribution efficiency and traffic circulation. The objective of this study is to propose an assessment method of truck route management systems in urban areas which includes more varied criteria. This research modified the two existing assessment indices of physical distribution efficiency and traffic circulation. In addition two new assessment indexes are proposed: (i) exposure indices for population directly influenced by nitrous oxide, a representative pollutant, and (ii) a friction index between trips for attending elementary school and freight vehicle trips. It was found that from the perspective of physical distribution efficiency and traffic circulation, the "before" alternative is better than "after". However, from the aspect of traffic safety and environmental impacts the "after" alternative is better than "before". It is expected that the proposed evaluation method in this study would be useful when identifying reasonable policies for truck route management in urban areas.

• YAKHAK HOEJI
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• v.40 no.6
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• pp.646-652
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• 1996

Epidermal Growth Factor (EGF), discovered by Stanley Cohen in 1960, has a potential healing effect for wounds and bums. Considering wound care, in order to avoid physical stress at the wound surface and efficiently apply EGF, the need for viscous spraying solutions was essential. Viscous spraying solutions containing EGF were prepared by utilizing viscosity-building polymer, poloxamer 407, and by introducing liposome systems. On the other hand, EGF is purified on reverse HPLC gradient program with the mobile solvent of acetonitrile. It is necessary to observe liposomal EGF changes as the acetonitrile contents varied in order to introduce liposome systems at the step of EGF solution (at the time of EGF purifying). By evaluating the size distribution and entrapment efficiency of EGF liposome, it was possible to detemine the limit contents of acetonitrile and establish the optimal conditions for solution formulations. It has been revealed that, as the acetonitrile content increases, mean diameter of EGF liposomes increased and the width of size distribution tends to decrease. The limit contents of acetonitrile were 10%, since there was little difference to the acetonitrile free liposomes.

• Journal of Forest and Environmental Science
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• v.23 no.2
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• pp.73-78
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• 2007

Ultrasonic deinkings of white ledger were carried out to confirm whether the ink removal efficiency and pulp qualities can be improved by the ultrasonic deinking. The effects of conventional pulping and ultrasonic treatment of white ledger on the ink particle size distribution and ink removal coefficient were compared. The physical properties of paper, energy consumption and effluent qualities were measured. The ultrasonic treatment of white ledger resulted in the ink particle size distribution suitable for flotation. The ink removal efficiency, brightness, breaking length and effluent quality were improved by the ultrasonic deinking. It is expected that the competitiveness of ultrasonic deinking system can be improved by the optimization of treatment condition.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.E
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• pp.1-7
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• 1998

This paper presents an experimental study for understanding the indoor air quality in a room. A model room, which had a ceiling-mounted supply and a sidewall-mounted exhaust, was used to examine the effect of air exchange rate (AER) and contaminant source location (CSL) as a function of the elapsed time. A tracer gas method, using carbon monoxide tracer, gas analyzers, and a data acquisition system, was applied to study the ventilation air distribution and the tracer removal efficiency, so-called pollutant removal efficiency, in the model room. The experiment was composed of two parts; firstly the AER was varied to examine its effect on the ventilation air distribution and the ventilation effectiveness and secondly both AER and CSL were considered to determine their effect on the pollutant removal efficiency. It was found that the ventilation effectiveness in the model was proportional to AER but not linearly. It was also found that changing the CSL can improve the pollutant removal efficiency. In some cases, the efficiency improvement by increasing AER was achieved by simply changing CSL.

• Journal of Environmental Science International
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• v.7 no.1
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• pp.36-40
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• 1998

This study was carried out to investigate the collection Efficiency of mass in collector step at the different of physical gas characterization. This work has focused on the dependence of the collection efficiency of mass in the collector zone of a two-stage set up field with gas temperature T and the dew point tmeperature. To identify the dependence of the mass collection efficiency on the Bounded plate of the collector zone MP.k by the spectre electric resistance of dust $p_e$. and the relative humidify ${\varphi}$, 20 at- tempts have been made with three different gas temperature ($50{\circ}C, 80{\circ}C, 110{\circ}C$) at different dew point. At the specific electric resistance of dust $p_e$=$10^6{\Omega}m$ which relative humidity corresponds to $\phi$ > 15%, a easy rise of the sounded plate secluded dust mass share was measured atwain. As the result of the higher cohesion imprisonment power due to the adsorbtion of particle, the rinse of the relative humidity developed on the particle surface. Therefore, the collection efficiency of mass was not predominant the high temperature T in the collector zone, neither was the pecific ellectric resistance of dust dependent.

• Journal of Korea Technology Innovation Society
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• v.3 no.3
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• pp.36-52
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• 2000

This study takes an issue of efficiency analysis in the presence of network effect utilizing the DEA (Data Envelopment Analysis) framework. Network effect has important policy implication for the regulation of local monopolies which undertake their business through physical network, such as electricity, natural gas, local telephony, etc. If the difference in spatial condition between companies is not controlled properly, the performance comparison and associated incentive regulation bear significant bias. In this study, we propose a methodology to measure the true managerial or technical efficiency apart from efficiency difference accruing from the difference in spatial condition. A series of modified DEA efficiency models are combined to investigate the extent of exogenous and endogenous efficiency component in the Korean natural gas distribution companies. Empirical results show that the network effect plays significant role in determining superficial performance difference.

• Journal of the Korean Society of Tobacco Science
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• v.23 no.2
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• pp.179-184
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• 2001

This study was conducted to determine the smoke component distribution and the relationship between chemical components and physical characteristics of cigarettes. 16 different cigarette brands which were sold in the market were selected for this study. Five kinds of smoke components which have been tar, nicotine, water, carbon monoxide(CO) puff No., and six kinds of physical characteristics which were filter type, leaf weight, filter weight, UPD, EPD, dilution rate were analyzed. The average values in tar, nicotine, water, CO concentration were 6.5 mg/cig. 0.66 mg/cig, 1.12 mg/cig. and 6.32 mg/cig., respectively. The average ratios of nicotine/tar and CO/tar were 0.10, and 1.02 respectively. The distribution of smoke components collected in the cambridge filter and cigarette filter was different. The averages of tar and nicotine removal efficiency by a cigarette filter were 53%, and 48%, respectively. All smoking components were positively correlated with other smoking components. filter types, EPD, and dilution rate were showed high correlation to the changes of smoke components. Especially, dilution rate of cigarette strongly affected on the changes of all smoke components.

• Journal of Korean Port Research
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• v.12 no.2
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• pp.233-242
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• 1998

The Inchon port has been heavily congested due to the tidal restriction in passing the lock and the shortage of berths or warehouses. The current congestion is predicted to become worse by the induced traffics near the lock entrance after completion of North harbour expansion and of Kyung-In canal construction. It is also expected that the newly developed configuration of the Inchon port will result in increasing the rate of marine accidents around the lock entrance because of the over-utilization of the limited capacity of the junction from the North harbour and the Kyung-In canal. This study adopts a systematic approach in analysing the physical distribution system of the inner-lock area in order to figure out alternative routes which are designed to improve the port efficiency. Ship maneuvering simulation is also attempted to propose a new approaching route to the canal as an alternative path in order to avoid the traffic accidents caused by the extreme congestion. The result of the ship maneuvering simulation demonstrates that the alternative routes by way of Buk-Sudo, Janbong-Sudo, north of Si-Do and Sin-Do is recommended routes which can satisfy the safety requirements of approaching to the canal entrance.

• The Journal of Fisheries Business Administration
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• v.18 no.2
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• pp.53-67
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• 1987

In the fish industry, the perishabiliy of raw material, saeasonality of catch and diatance between production and consumption combine to cause physical distribution to be a difficult decision problem. In fishery physical distribution, the choice of appropriate landing port is a major problem. This paper deals with transshipment model to determine landing port as intermediate transfer point and the market to which fish should be sent. Transshipment model is useful to determine intermediate transfer point and can be reformulated as LP model. So this study developes transshipment model for korea large trawler ana analized the model output. It can be expended to a realistic problem in order to provide information to port planner and decision maker on the trade-offs between the cost and efficiency of fishery transportation.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.4
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• pp.471-478
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• 2011

A series of laboratory experiments carried out to investigate the particle separation efficiency and flotation characteristics using $CO_2$ bubbles. The primary objective of this study was to find out the feasibility of $CO_2$ bubbles as an applicable unit of flotation process in tap-water and wastewater treatment plant. The fundamental measurements were conducted to characterize the $CO_2$ bubble from the physical viewpoint in water including bubble size distribution and rising velocity under various operational conditions. In addition, the removal efficiency of solid was experimented using the lab scale plant applied $CO_2$ bubbles, namely the dissolved carbon dioxide flotation (DCF) process. The DCF process using carbon dioxide bubble, which is an advantage as the decrease and the reuse of Green-House gas, can be a promising technology as an water treatment process. On the other hand, the further research to decrease the bubble size distribution of $CO_2$ is required to enhance the particle separation efficiency.