Coal-tar pitch, a feedstock which can be heat-treated to create graphite, is composed of very complex molecules. Coal-tar pitch is a precursor of many useful carbon materials (e.g., graphite, carbon fibers, electrodes and matrices of carbon/carbon composites). Modified coal-tar pitch (MCTP) was prepared using two different heat-treatment methods and their properties were characterized and compared. One was prepared using heat treatment in nitrogen gas; the other was prepared under a pressure of 350 mmHg in air. The MCTPs were investigated to determine several properties, including softening point, C/H ratio, coke yield, formation of anisotropic mesophase and viscosity. The MCTPs were subject to considerable changes in chemical composition due to condensation and polymerization in the used-as-received coal-tar pitch after heat-treatment under different conditions. The MCTPs showed considerable increases in softening point, C/H ratio, and coke yield, compared to those of as-received coal-tar pitch. The MCTP formed by heat-treatment in nitrogen showed isotropic phases below 350˚C for 1 h of soaking time. However, MCTP heat-treated under high pressure (350 mmHg) showed isotropic phases below 300˚C, and showed anisotropic phases above 350˚C, for 1 h of soaking time. The viscosity of the MCTPs increased with increase in their softening points.

Commercial activated-carbon used as the electrode material of an electric double-layer capacitor (EDLC) was posttreated with various acids and alkalis to increase its capacitance. The carbon samples prepared were then heat-treated in order to control the amount of acidic functional groups formed by the acid treatments. Coin-type EDLC cells with two symmetric carbon electrodes were assembled using the prepared carbon materials and an organic electrolyte. The electrochemical performance of the EDLC was measured by galvanostatic charge-discharge, cyclic voltammetry, and electrochemical impedance spectroscopy. Among the various activated carbons, the carbon electrodes (CSsb800) prepared by the treatments of coconutshell-based carbon activated with NaOH and H3BO5, and then heat treated at 800˚C under a flow of nitrogen gas, showed relatively good electrochemical performance. Although the specific-surface-area of the carbon-electrode material (1,096m2/g) was less than that of pristine activated-carbon (1,122m2/g), the meso-pore volume increased after the combined chemical and heat treatments. The specific capacitance of the EDLC increased from 59.6 to 74.8 F/g (26%) after those post treatments. The equivalent series resistance of EDLC using CSsb800 as electrode was much lower than that of EDLC using pristine activated carbon. Therefore, CSsb800 exhibited superior electrochemical performance at high scan rates due to its low internal resistance.

Silicon-carbon composite was prepared by the magnesiothermic reduction of mesoporous silica and subsequent impregnation with a carbon precursor. This was applied for use as an anode material for high-performance lithium-ion batteries. Well-ordered mesoporous silica(SBA-15) was employed as a starting material for the mesoporous silicon, and sucrose was used as a carbon source. It was found that complete removal of by-products (Mg2Si and Mg2SiO4) formed by side reactions of silica and magnesium during the magnesiothermic reduction, was a crucial factor for successful formation of mesoporous silicon. Successful formation of the silicon-carbon composite was well confirmed by appropriate characterization tools (e.g., N2 adsorption-desorption, small-angle X-ray scattering, X-ray diffraction, and thermogravimetric analyses). A lithium-ion battery was fabricated using the prepared silicon-carbon composite as the anode, and lithium foil as the counter-electrode. Electrochemical analysis revealed that the silicon-carbon composite showed better cycling stability than graphite, when used as the anode in the lithium-ion battery. This improvement could be due to the fact that carbon efficiently suppressed the change in volume of the silicon material caused by the charge-discharge cycle. This indicates that silicon-carbon composite, prepared via the magnesiothermic reduction and impregnation methods, could be an efficient anode material for lithium ion batteries.

PURPOSES: The purpose of study is to come up with ideas to improve both the use of the public bicycle and the practicality of the public bicycle system as well. METHODS: The study carried out an analysis on factors which would influence user's satisfaction by using a structural equation and then, discussed what the current public bicycle system should do to make improvements of its own. In order to Satisfaction of the public bicycle system( “Tashu”) in Daejeon city survey was conducted users and was based on statistical analysis SPSS 20 program, structural equation modeling program AMOS 20 was used for analysis. In addition, the reliability and validity of each question was conducted verification, to verify the hypothesis using structural equation model. RESULTS : According to the results of the analysis with the structural equation used, the connectivity, the convenience, the economic efficiency and the reliability in order were observed to have an influence on the satisfaction of the users CONCLUSIONS : The connectivity turned out to be a factor that would have the greatest concern with the satisfaction of the users. This finding was, therefore, interpreted that people who would ride the public bicycles understand them as more of a transit system that would take them, the people themselves, to another transfer rather than as some immediate transit system.

본 연구는 국내 유통 방풍(S. divaricata, P. japonicum, G. littoralis) 한약재의 원산지 판별을 위해 수행 되었다. 이를 위 해, 형태적 특징비교 뿐만 아니라 엽록체(nrDNA-ITS2) 및 핵 DNA 바코드 유전자(cpDNA-matK, psbA-trnH, rpoB2와 rpoC1)를 이용한 염기서열 분석을 수행하였다. 방풍류 3종의 형태적 특징을 비교한 결과, 잎 모양과 거치의 형태에서 가장 큰 차이를 보인 반면, 건조약재의 경우 육안으로 구별하기에 어려움이 있었다. DNA 수준에서의 차이를 비교하기 위해 DNA 바코드 후보 유전자들을 이용한 방풍류 3종의 식물자원 에 대한 염기서열 분석을 수행한 후 판별 마커 개발 가능성이 있는 ITS2와 matK, psbA-trnH 세 primer를 선발하였다. 이 를 국내 유통 한약재에 적용한 경우 방풍은 S. divaricata와, 식방풍은 P. japonicum과, 해방풍은 G. littoralis와 동일한 것 으로 확인되었다. 중국산 방풍은 S. divaricata와 동일종으로 바르게 표기되어 유통되나, 국산 방풍은 P. japonicum과 동일 종으로 식방풍(갯기름나물)의 뿌리를 건조시켜 방풍으로 혼용 유통됨을 확인하였다. ITS2 구간의 염기서열 분석 결과, 식방 풍의 경우 두 그룹으로 나눠져 동일 종 내에 유전적 변이가 있음이 확인되었다. 따라서 본 연구결과 방풍류 3종 판별을 위 해 nrDNA-ITS2와 cpDNA-matK, psbA-trnH의 사용이 유용 할 것이며, 차후 방풍류 한약재의 판별을 위한 마커 개발 연 구의 기초 자료로서 활용될 수 있을 것으로 사료된다.

PURPOSES : Lately, a traffic information market has been developed with a rapid speed owing to information and communications. In this situation, a study on the use intention and the satisfaction of mobile transportation information applications of users will be diverse implications and a strategic foundation to local governments and transportation information related enterprises that should provide satisfactory info as public goods to much more users. METHODS : Going along with the flow, this study establishes features of the mobile transportation information applications aiming to the users and analyzes empirical causality for effects of the use intension and the satisfaction. Through this study's analysis, targeting users having experienced transportation information applications among smart phone users, a survey was conducted and characteristics of the transportation information applications were lighted and the effects of the use intention and the satisfaction were analyzed using a technology acceptance model. RESULTS : The analysis result was that Accuracy, Riskiness, Ubiquity and Interactivity as all attributes of transportation information applications have a significant effect on Perceived usefulness and Perceived Ease of Use respectively. The Perceived usefulness and Perceived Ease of Use have affected significantly users' satisfaction respectively, so consequentially this shows effect relationship leading to reuse intention. CONCLUSIONS : The Perceived usefulness and Perceived Ease of Use all for the transportation information applications were shown to influence significantly on the satisfaction. With this kind of result, if users obtain positive outcomes such as travel time reduction or effective roles on their tasks through the transportation information applications, they feel the satisfaction for using and eventually these affect positively to the reuse intention of those transportation information applications.

Coconut shell 계 상용 활성탄을 후처리하여 EDLC 전극재로 적용하였다. Coconut shell계 활성탄을 별도의 처리없이 EDLC 전극재로 사용하였을 때, 초기 무게용량 및 부피용량은 66 F/g 및 39 F/cc이었고, 100 사이클 충 방전을 반복한 후, 각각 54 F/g 및 32 F/cc로 감소하여 82%의 충 방전효율을 나타내었다. 충 방전 반복에 따른 용량의 감소폭이 크며, CV 특성에서 부반응에 의한 분극현상이 발생하여 전극재로 적합하지 않았다. 상업용 활성탄에 포함된 불순물을 효율적으로 제거하기 위하여 알칼리 및 산 처리를 하였고, 그 후 세공 분포와 표면의 산성 관능기 함량을 제어하기 위하여 질소 분위기에서 열처리하였다. 알칼리 및 질산처리 한 후 800℃에서 열처리한 전극재의 경우, 초기부피용량 44 F/cc, 100사이클 후 42 F/cc로서 실용화 가능한 수준의 높은 부피용량 및 95% 이상의 높은 충 방전 효율을 나타내었다.

Coal tar is the primary feedstock of premium graphitizable carbon precursor. Coal tars are residues formed as byproducts of thermal treatments of coal. Coal tar pitches were prepared through two different heat treatment schedules and their properties were characterized. One was prepared with argon and oxidation treatment with oxygen; the other was prepared with oxygen treatment at low temperature and then argon treatment at high temperature; both used coal tar to prepare coal tar pitches. To modulate the properties, different heat treatment temperatures (300~400˚C) were used for the coal tar pitches. The prepared coal tar pitches were investigated to determine several properties, such as softening point, C/H ratio, coke yield, and aromaticity index. The coal tar pitches were subject to considerable changes in chemical composition that arose due to polymerization after heat treatment. Coal tar pitch showed considerable increases in softening point, C/H ratio, coke yields, and aromaticity index compared to those characteristics for coal tar. The contents of gamma resin, which consists of low molecular weight compounds in the pitches and is insoluble in toluene, showed that the degree of polymerization in the pitches was proportional to C/H ratio. Using an oxidizing atmosphere like air to prepare the pitches from coal tar was an effective way to increase the aromaticity index at relatively low temperature.

PURPOSES : In this study, the effects of when median exclusive bus lanes were applied to Daejeon trunk road (Wolpyeng crossway~Seodaejeon crossway, 6.3km) and (Daeduck Bridge 4~Kyeryong 4, 2.6km) by Microscopic Simulation VISSIM (5.0) was studied. The median exclusive bus lanes are one of the measures of transportation system manage techniques that can especially improve the efficiency of public transportation facilities. METHODS : According to the analysis of VISSIM on the Gyerong mainroad and Daedeok mainroad, when the median exclusive bus lanes were applied unlike when the roadside bus-only lanes were applied, the average travel speed of vehicles decreased but the average delay time and travel time increased. This arised from the changes in the geometric structure of the road which occurred the reduction of vehicle lane in the center of the road. RESULTS : In the case of bus, on the other hand, the average travel speed increased but the average delay time and travel time decreased. This is because the problems such as illegal parking and stopping, secondary road in out vehicle, and conflict of intersection right turn that roadside bus-only lanes occurred was solved. CONCLUSIONS : Although the introduction of median exclusive bus lanes will have a negative effect on general traffic flow due to the aggravation of travel, decrease of passenger car usage will lead to decrease of traffic volume. Therefore, smooth vehicle travel is expected.

PURPOSES: The urban traffic problems can be defined as general problems for smooth traffic flow including maintenance of mass transportation system according to suddenly increased population, traffic regulations for vehicles and pollution problem. As a method for solving traffic jams, one of the traffic problems of late, interest in Intelligent Traffic System(ITS) is increasing sharply, which is a system managing traffic demand by providing passers with information on traffic state of path and road conditions before they pass the road through ATIS, a field of ITS. METHODS: Variable message signs(VMS) is used on the roads as a method for providing information to promote smooth traffic flow and safety and prevent traffic accidents in advance by providing drivers with various information while driving. RESULTS: Recently, as ITS industry has been vitalized and technical factors of VMS have developed, various kinds of information is provided but the effect of VMS has not been maximized due to its limited type. CONCLUSIONS: Therefore, this study intends to provide methods for effective information transfer by analyzing driver's visual behavior characteristics for VMS and presenting a basis for maximizing VMS effect after considering read by expression type.

PURPOSES: The number of traffic accidents in 2010 was 226,978 in Korea, a high percentage of which up to 12.61% was due to drunk driving. As it is expected that the number of traffic accidents will increase because of the drastic increase of the number of vehicle registrations and the prevalent drinking cultures, it is necessary to understand the driving characteristics of drunken drivers to lower the increasing rate. METHODS: This study, therefore, comparatively analyzes the two groups - one group before drinking and the other after drinking - based on the graph, and implements the correlation in each scenario(1,2,3). scenario 1. appearance of jaywalkers; scenario 2. appearance of an illegal left-turning car; and scenario 3. appearance of a vehicle and a person as obstacles to the driver after an accident. RESULTS: The comparative analysis of speed shows that the group after drinking was 50km/h faster than the group before drinking in Scenario 1, 20km/h in Scenario 2, and 15km/h in Scenario 3 respectively. In the comparative analysis of acceleration, the average level of the group after drinking was 0.15 higher than that of the group before drinking in Scenario 1, 0.30 in Scenario 2, and 0.15 in Scenario 3. In the comparative analysis of deceleration, the average level of the group after drinking was about 0.4 lower than that of the group before drinking in Scenario 1, 0.35 in Scenario 2, and 0.2 in Scenario 3 respectively. In the comparative analyses, the item of speed, acceleration and deceleration was of significance for each group in Scenarios. CONCLUSIONS: The comparative analysis demonstrated that there is a difference between the group before drinking and the group after drinking. In the analysis of correlation in each group, it was proved that the drunken group was of significance.

Canine parvovirus (CPV) type 2a (CPV-2a) has recently been identified as the main genotype circulating in the dog population in South Korea. Although CPV vaccines protect domestic dogs from CPV-2 infection, the efficacy of commercial live or inactivated CPV vaccines against CPV-2a has not been reevaluated. In this study, dogs were immunized with one of 7 commercial CPV vaccines (4 modified live and 3 inactivated vaccines) followed by challenge with CPV-2a strain, KV0901 that had been isolated from naturally infected dog in 2009. All dogs vaccinated twice with 4 commercial modified live CPV vaccines were seroconverted (geometric mean HI titer > 190.2) and most of dogs were completely protected against virulent CPV-2a strain infection. The dogs inoculated with 3 commercial inactivated CPV vaccines were also seroconverted and showed a slight loss of appetite and light diarrhea for 4 days after challenge and returned to normal at 5 days post challenge. However, the non-vaccinated dogs revealed the typical clinical signs of CPV infection including haemorrhgic diarrhea. In conclusion, the 4 live CPV vaccines licensed in Korea cross-protected dogs against virulent challenge with CPV-2a and are applicalble to pet dogs for the prevention of CPV infection.

Expanded graphites were used as anode materials of high power Li-ion secondary battery. The expanded graphite was prepared by mixing the graphite with HClO4 as a intercalation agents and KMnO4 as a oxidizing agents. The physical and electrochemical properties of prepared expanded graphites through the variation of process variables such as contents of intercalation agent and oxidizing agent, and heat treatment temperature were analyzed for determination of optimal conditions as the anode of high power Li-ion secondary battery. After examing the electrochemical properties of expanded graphites at the different preparing conditions, the optimal conditions of expanded graphite were selected as 8 wt.% of oxidizing agent, 400 g of intercalation agent for 20 g of natural graphite, and heat treatment at 1000℃. The sample showed the improved charge/discharge characteristics such as 432 mAh/g of initial reversible capacity, 88% of discharge rate capability at 10 C-rate, and 24 mAh/g of charge capacity at 10 C-rate. However, the expanded graphite had the problems of potential plateaus like natural graphite and lower initial efficiency than the natural graphite.

In this paper considered is the provisioning quantity determination problem of consumable concurrent spare parts (CSP) of a new equipment system to minimize the procurement cost under the operational availability constraint. When a part fails, repair of t

경제성장과 함께 삶의 질이 향상됨에 따라 도로 계획 및 설계분야에서도 기능 중심의 설계에서 이용자들의 시각 및 심리적 특성인 감성을 고려한 경관 중심의 설계로 변화하고 있다. 이에 본 연구에서는 다양하게 조사된 감성형용사들을 개인의 감성인지 특성 차이를 최소화 하면서 객관적이고 합리적인 추출 방법을 제안하고자 한다. 먼저 어의구별법(Semantic Differential)의 5점 척도에 의해 조사된 감성형용사를 바탕으로 기존 연구에서 사용한 요인분석과 본 연구에서 제안하는 판별분석을 통해 감성형용사를 추출하고 상관 분석을 통해 대표적인 감성형용사를 추출한 후 수량화 I 모형을 구축하였다. 그리고 구축된 수량화 모형을 이용하여 만족도를 예측한 후 실제 관측 만족도와의 쌍체비교 검증을 통하여 판별 및 상관분석에 의한 방법이 실제 관측 만족도와 가장 유사한 것으로 분석되어 연속적인 도로경관 설계시 판별 상관분석에 의해 적용가능한 감성요인을 파악하는 것이 적합한 방법임을 확인할 수 있었다.

  The National Wealth Survey Method has been used to estimate capital stocks in Korea by the Korea National Statistical Office in every 10 years. However, this method requires huge amount of time and money. Since the Benchmark Year Method also has similar

Methanol and formaldehyde were produced directly by the partial oxidation of methane. The catalysts used were mixed oxides of late-transition metals, such as Mn, Fe, Co, Ni and Cu. The reaction was carried out at 450℃, 50 bar in a fixed-bed differential reactor. The prepared catalysts were characterized by XRD, TPD and BET apparatus. Of the catalysts, A-Mn0.2-6, which contains 0.2 mole of Mn and calcined at 600℃, showed the best catalytic activity: 3.7% methane conversion, and 30 and 28% methanol and formaldehyde selectivities, respectively. The catalytic activity was changed with the content of Mn and the calcination temperature. Catalytic activity increased with the specific surface areas of the catalysts. With XRD, it was found that the structure of the catalysts are changed with calcination temperature. Through O2-TPD experiment, it was found that the catalysts showing good catalytic activity showed O2 desorption peak around 800℃.