• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.2
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• pp.44-61
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• 2022

With the increase of truck traffic, roads are becoming more congested and the risk of accidents is also increasing. Since the fatality rate of traffic accidents caused by trucks is about 2 to 3 times higher than that of passenger cars and buses, it is urgent to prepare policies for truck traffic safety. While most of the previous studies focused on factor analysis that contributes to traffic accidents, this study presented traffic safety policies (4 major-criteria and 12 sub-criteria) for trucks through driver interviews and previous studies. Then, the priority of the policies was evaluated by using Fuzzy-AHP. As a result, the improvement of truck drivers' working environment was evaluated as the most important criteria, and followed by the improvement of road traffic conditions. In detail, there is an urgent need to improve the freight car fare system, ensure sufficient rest for drivers, and strengthen the crackdown of illegal parking and stopping along roads. This study is expected to be usefully utilized in preparing traffic flow safety policies in preparation for the continuous increase of truck traffic.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.2
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• pp.120-127
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• 2011

Purpose: The purpose of this study was to examine the effects of chromium chloride addition on coloration, mechanical property and microstructure of 3Y-TZP. Materials and methods: Chromium chloride was weighed as 0.06, 0.12, and 0.25 wt% and each measured amount was dissolved in alcohol. $ZrO_2$ powder was mixed with each of the individual slurry to prepare chromium doped zirconia specimen. The color, physical properties and microstructure were observed after the zirconia specimen were sintered at $1450^{\circ}C$. In order to evaluate the color, spectrophotometer was used to analyze the value of $L^*$, $C^*$, $a^*$ and $b^*$, after placing the specimen on a white plate, and measured according to the International Commission on Illumination (CIE) standard, Illuminant D65 and SCE system. The density was measured in the Archimedes method, while microstructures were evaluated by using the scanning electron microscopy (SEM) and XRD. Fracture toughness was calculated Vickers indentation method and indentation size was measured by using the optical microscope. The data were analyzed with 1-way ANOVA test (${\alpha}$ = 0.05). The Tukey multiple comparison test was used for post hocanalysis. Results: 1. Chromium chloride rendered zirconia a brownish color. While chromium chloride content was increased, the color of zirconia was changed from brownish to brownish-red. 2. Chromium chloride content was increased; density of the specimen was decreased. 3. More chromium chloride in the ratio showed increase size of grains. 4. But the addition of chromium chloride did not affect the crystal phase of zirconia, and all specimens showed tetragonal phase. 5. The chromium chloride in zirconia did not showed statistically significant difference in fracture toughness, but addition of 0.25 wt% showed a statistically significant difference (P<.05). Conclusion: Based on the above results, this study suggests that chromium chlorides can make colored zirconia while adding in a liquid form. The new colored zirconia showed a slight difference in color to that of the natural tooth, nevertheless this material can be used as an all ceramic core material.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.179.2-179.2
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• 2011

바이오매스 가스화 프로세스 개발에 있어서 가장 기본적인 해결과제는 고발열량의 합성가스 제조, 냉가스 효율의 향상, 타르 발생량 저감 및 제거이다. 가스화 효율 향상에 대한 연구는 국내외 적으로 많이 이루어지고 있으나, 타르 발생량 저감에 대한 연구는 많이 이루어져 있지 않다. 타르는 분자량이 큰 방향적 탄화수소로 응축되면 점성이 높아 배관폐쇄, 정제설비의 압력손실 증가로 인해 운전정지 및 가스화율 저하의 원인이 된다. 가스화로에서 타르 발생량을 저감시키는 방법 중에는 Ni계 촉매를 이용하는 방법이 있으나, 카본 누적에 의한 활성저하, 알칼리금속에 의한 응집 등의 문제가 발생할 수 있다. 한편 철산화물은 합성가스 중의 C2-C3계의 타르를 분해하는데 효과가 알려져 있다. 따라서 본 연구에서는 적벽돌, 염색슬러지 회재 등에는 철산화물이 다량 함유되어 있는 것에 착안하여 폐기물중의 폐금속을 이용한 바이오매스 가스화에 대한 연구를 수행하였다. 점토광물계 폐기물인 적벽돌 파쇄물($SiO_2$ 67.2%, $Al_2O_3$ 19.7%, $Fe_2O_3$ 8.7%, $K_2O$ 2.0%, $TiO_2$ 1.2%, MgO 0.7%)을 전처리 한 후 유동매체로하여 우드펠렛을 가스화한 결과, 가스 생성량이 증가하고, 타르 및 탄화수소류가 감소하는 경향을 나타내었다. 특히 타르는 후단의 타르 트랩에서 타르가 거의 검출이 되지 않았다. 전처리를 하지 않은 적벽돌 파쇄물은 반응시간이 경과한 후에 가스화율이 증가함에 따라 철화합이 가스화로내에서 환원되어 타르를 분해하는데에는 어느 정도의 반응시간이 필요한 것을 확인하였다.

• Journal of Nutrition and Health
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• v.52 no.6
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• pp.540-551
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• 2019

Purpose: Dietary fiber is a component of carbohydrate that is linked closely with the carbohydrate quality, but few studies have investigated the association of high fiber intake with the cardiometabolic risk factors in Koreans. This study examined the association of high fiber and high carbohydrate intake with the cardiometabolic risk factors among Korean adults. Methods: This study included 15,095 adults aged ≥20 years, who participated in the 2013 ~ 2017 KNHANES. The dietary intake was obtained using a 24-h dietary recall method. The associations of high fiber and high carbohydrate intake with metabolic syndrome and dyslipidemia were examined by sex using multiple logistic regression analysis. Results: The median of dietary fiber was 23.6 g/day in men and 20.0 g/day in women. Dietary fiber intake increased gradually as dietary carbohydrate groups increased except for ≥80% of energy from the carbohydrate group. Women in the highest quintile of fiber intake showed a 33% lower risk of metabolic syndrome compared with those in the third quintile. When stratified into low fiber (LF) and high fiber (HF) groups using Adequate Intake of fiber for Koreans, men in the third quartile of carbohydrate intake showed a 44% and 51% higher risk of metabolic syndrome and atherogenic dyslipidemia than in the first quartile, respectively, but only in the LF group. Women in the second quartile of carbohydrate intake showed an 83% higher risk of hypercholesterolemia than in the first quartile in the LF group. On the other hand, as no significant association was observed between the carbohydrate intake and metabolic diseases among the HF groups in both sexes. Conclusion: These findings suggest that a high fiber intake might be associated with a reduced risk of metabolic syndrome and high carbohydrate intake with a low dietary fiber intake might be associated with an increased risk of several metabolic abnormalities among Korean adults. Further prospective studies will be needed to confirm the effects of high fiber and high carbohydrate intake on the cardiometabolic risk factors among Koreans.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.1
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• pp.57-64
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• 2020

The IOPC Fund general assembly reported that the International Convention on Liability and Compensation for Damage in Connection with the Carriage of Hazardous and Noxious Substances by Sea (known as the HNS Convention) will meet the requirement for the convention to take ef ect between 2021 and 2022. When the convention comes into effect, the liability-limit insurance of the HNS transport ship will be enforced and the shipper receiving the HNS will pay the share of the contribution from the International Fund for damages exceeding the limit of the ship's liability insurance. Korea is one of the major shipping and shipper countries in the world; thus, this study aimed to the need to analyze the effect of the convention on the related industries. The survey of ships and contribution targets analyzed the research data of the Ministry of Oceans and Fisheries. The P&I premium estimation was reviewed by the Korea Shipping Association and the K P&I as insured ships. In addition, the contribution of the HNS cargo volume was analyzed in an annual report by a representative international association for each cargo. About 1,500 ocean-going and domestic vessels have been identified as ships subject to the convention. The effect of changes in premiums under the convention was minimal for most ships. The effect of the shipping industry is expected, with about 150 domestic tankers expected to increase insurance premiums. In the case of shipper industries, 52 freight terminals were found to be eligible for the payment of the share of the international fund, as the proportion of freight volume in Korea was ranked second to fourth in the world by individual HNS accounts. This implies the obligation to pay contributions according to the convention. Considering the status of HNS transport ships entering and leaving ports and the quantity of HNS cargo, it can be concluded that the validity of Korea's convention is sufficient and that, it is necessary to coordinate with global major shipper countries.

• Journal of Navigation and Port Research
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• v.30 no.3 s.109
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• pp.203-209
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• 2006

Maritime transport has been occupying the biggest part of the container transportation market. With regard to container terminal management, the planning technology and the space allocation system on the yard are very significant factors to secure the stability of ship and to ensure the reliability of schedules of ship throughout keeping barycenter of vessel by right loading and fast handling of cargoes. The purposes of this paper are to illustrate the existing yard management systems such as Grouping method and Random Grounding method, and then to evaluate and compare the efficiency of yard availability between the existing management system(Grouping method) and Random Grouping which uses the forecasted inbound cargo volume at the gate by Time Base Operation.

• Journal of Distribution Research
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• v.4 no.3
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• pp.1-22
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• 2000

Many foreign freight forwarders make inroads into domestic markets. Korean freight forwarders are not competitive on th domestic logistics area because of higher customer services by foreign freight forwarders in Korea. The purpose of this research is to analyze degree of satisfaction on customer services attributes of freight forwarders in Korea, and to strengthen the competitiveness of customer services by Korea freight forwarders in contrast to foreign investment freight forwarders in Korea. The results of the research could be summarized as follows.: When freight forwarders are selected, the most important customer service attributes have been ranked in order with 'the accuracy management of shipping order' , the reasonable offers of freight rate' and 'the quick arrangement of vessels' when freight forwarders are selected.

• Clean Technology
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• v.20 no.2
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• pp.154-159
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• 2014

In this study, PVC-LMO beads were prepared by immobilizing lithium manganese oxide (LMO) with poly vinyl chloride (PVC) diluted in dimethyl sulfoxide (DMSO) solvent on behalf of N-methyl-2-pyrrolidone (NMP). XRD analysis confirmed that LMO was immobilized well in PVC-LMO beads. The diameter of PVC-LMO beads synthesized by DMSO was about 4 mm. The adsorption experiments of lithium ions by PVC-LMO beads were conducted batchwise. The maximum adsorption capacity obtained from Langmuir model was 21.31 mg/g. The adsorption characteristics of lithium ions by PVC-LMO beads was well described by the pseudo-second-order kinetic model. It was considered that the internal diffusion was the rate controlling step.

• Journal of Navigation and Port Research
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• v.44 no.1
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• pp.44-52
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• 2020

More accurate forecasting of port cargo in the global long-term recession is critical for the implementation of port policy. In this study, the Busan Port container volume (export cargo and transshipment cargo) was estimated using the Vector Autoregressive (VAR) model and the vector error correction (VEC) model considering the causal relationship between the economic scale (GDP) of Korea, China, and the U.S. as well as ARIMA, a single volume model. The measurement data was the monthly volume of container shipments at the Busan port J anuary 2014-August 2019. According to the analysis, the time series of import and export volume was estimated by VAR because it was relatively stable, and transshipment cargo was non-stationary, but it has cointegration relationship (long-term equilibrium) with economic scale, interest rate, and economic fluctuation, so estimated by the VEC model. The estimation results show that ARIMA is superior in the stationary time-series data (local cargo) and transshipment cargo with a trend are more predictable in estimating by the multivariate model, the VEC model. Import-export cargo, in particular, is closely related to the size of our country's economy, and transshipment cargo is closely related to the size of the Chinese and American economies. It also suggests a strategy to increase transshipment cargo as the size of China's economy appears to be closer than that of the U.S.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.2
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• pp.54-60
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• 2023

In this study, microstructure and basic property analysis of DG (Desulfurization gypsum) and CCMs (Carbondioxide conversion capture materials) made by reacting CO₂ with DG were conducted to analyze applicability as a cement admixture. The main crystalline phases of DG were CaO and CaSO₄, and CCMs were CaSO₄, CaCO₃, Ca(OH)₂ and CaSO₄·H₂O. As a result of particle size analysis, the difference in average particle sizes between the two materials was about 7 ㎛. No major heavy metals were detected in the CCMs, and as a result o f TGA, the CO₂ decomposition of CCMs was more than twice as high as that of DG. Therefore, it was judged that CCMs could be used as a cement admixture through optimization of manufacturing conditions. As a results of measuring the strength behavior of DG and CCMs mixture ratios, the long-term strength of CCMs-mixed mortar was higher, and this is due to the filler effect of CaCO₃ in CCMs.