• Transactions of the Korean hydrogen and new energy society
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• v.21 no.1
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• pp.26-34
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• 2010

The electrocatalystic prperties of Pt-Co and Pt-Ni with heteropolyacids (HPAs) entrapped in covalently cross-linked sulfonated poly(ether ether ketone) (CL-SPEEK)/HPA membranes were investigated for water electrolysis. The HP As, including molybdophosphoric acid (MoPA), and tungstophosphoric acid (TPA) were both used as membrane additives and electrocatalysts. The membrane electrode assembly (MEA) was prepared by a nonequilibrium impregnation-reduction (I-R) method. $Pt(NH_3)_4Cl_2$, $NiCl_2$ and $CoCl_2$ as electrocatalytic materials and $NaBH_4$ as reducing agent were used. I order to enhance electrocatalytic activity, the catalyst layer prepared above was electrodeposited (Dep) with HP A. Surface morphologies and physico-chemical properties of MEA were investigated by means of SEM, EDX and XRD. The electrocatalytic properties of composite membranes such as the cell voltage and coulombic charge in CV were in the order of magnitude: CL-SPEEK/MoPA40 (wt%) > CL-SPEEK/TPA30 > Nafion117. In the optimum cell applications for water electrolysis, the cell voltage of Pt/CL-SPEEK-MoPA40/Pt-Co (Dep-MoPA) and Pt/CL-SPEEK-TPA30/Pt-Co (Dep-TPA) was 1.75 Vat $80^{\circ}C$ and $1\;A/cm^2$ and voltage efficiency was 87.1%. Also, the observed activity of Pt-Co (84:16 atomic ratio by EDX) is a little higher than that of Pt-Ni (86: 14). The current density peak of electrodeposited electrodes were better a little than those of unactivated electrodes based on the same membranes.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.2
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• pp.151-158
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• 2016

Tidal farm is a multi-arrayed turbine system for utilizing tidal stream energy. For horizontal-axis turbine(HAT) system, it is recommended that each unit has to be deployed far apart in order to avoid hydrodynamic interference among turbines, as proposed by the European Marine Energy Centre(EMEC). But there is no rule for the arrangement of vertical-axis turbine(VAT) yet. Moreover it has been reported that a proper arrangement of adjacent turbines can enhance the overall efficiency even greater than an arrangement without mutual interference effect. This paper suggests the layout of VATs showing the better performances, which turned out to be quite different from HATs' arrangement. Numerical calculations were performed to investigate the performance variation in terms of the rotational direction as well as the distance between turbines. It has been shown that the best combination of rotational direction and distance between turbines can increase its performance higher about 9.2% than that of two independently operated turbines. It is likely that such improvement is due to the increased velocity between adjacent turbines. For diagonally arranged turbines, the maximum normalized mean power coefficient was obtained to be higher about 5.6% than that of two independent turbines. It is expected that the present results can be utilized for conceptual design of tidal farm to harness the tidal stream energy.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.2
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• pp.141-146
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• 1982

Laboratory and greenhouse experments were conducted to find out the optimum dilution time of methane fermented effluent of hog waste which was high pH (7.85), $NH_4$-N (683ppm), electric conductivity (8.3mmhos/cm) and BOD (about 1,000ppm) and the interval of effluent change which will provide maximun yield of green algae (Scenedesmus accuminatus), duck weed (Lemner minor L.) and Azolla anabaena (Azolla pinnata). The results of this experiment are summerized as follows. 1. The maximum yield were obtained at 5 times diluted effluent ($NH_4$-N : 137ppm) and exchange of 4 day intertval, from 25 times to 50 times dilution ($NH_4$-N : 7-14ppm) and 4 day interval, and 50 times dilution ($NH_4$-N : 14 ppm) and exchange the effluent at 4-8 day interval for green algae, duck weed and azolla growth, respectively. 2. Purification of the effluent was enhenced by growth of the green algae, duck weed and azolla due to decrease of pH, $MH_4$-N and electric conductivity of effluent. The degree of purification was higher in case of azolla growth than duck week growth.

• Food Science and Preservation
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• v.24 no.5
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• pp.576-584
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• 2017

With the goal of developing a new functional fermentation milk using green tea powder (GP), milk was fermented with direct vat set (DVS) starter culture containing Streptococcus salivarius subsp. thermophilus, Lactobacillus paracasei and L. delbrueckii subsp. bulgaricus. We investigated fermentation characteristics and antioxidative activities of fermented milk supplemented with different concentrations (0.5, 1, 2, 3%) of GP. All samples were evaluated for pH, total acidity, viable cell count, and sugar contents. The pH of all samples decreased during fermentation, and the final pH ranged from 4.35 to 4.51. The acidity increased during fermentation, after the fermentation was completed, the titratable acidity was 0.8 to 1.1%. And viable cell count of all samples increased during fermentation, and the final viable cell count was 8.57 to 8.89 log CFU/mL. The sugar content decreased as the fermentation proceeded and finally reached 12 to $13^{\circ}Brix$. And increasing GP, decreased brightness and increased yellowness. Increasing GP concentration added to milk, improved DPPH free radical scavenging activity and ferric ion reducing activity of fermentation milk. The fermentation milk kept their pH, total acidity and viable cell counts standard of fermentation milk during the storage period at $4^{\circ}C$. These findings confirmed the possibility of development of the novel functional fermentation milk through the investigation of the quality characteristics of the fermentation milk added with GP.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.5
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• pp.725-731
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• 2008

The principal objective of this study was to assess the effects of low-calorie diets(LCD) for 8 weeks of medical nutrition therapy in individuals with BMI in excess of $23\;kg/m^2$. 41 over-weight or obese individuals (male=14, female=27, age $28.6{\pm}8.9\;yrs$), none of whom were diagnosed with a medical disease, were administered MNT 4 times over the study period. Approximately $1,100{\sim}1,300\;kcal/day$ were prescribed by a dietitian, via individualized counseling. Anthropometric parameters, daily nutrient intake, and blood levels of leptin, insulin, and lipid profiles were measured prior to and after the 8 weeks of the intervention period. We noted significant reductions in body weight, body mass index (BMI), fat mass (FM), visceral adipose tissue (VAT), abdominal skin-fold thickness, and waist circumference in both men and women. The mean body weight losses in men and women were $3.2{\pm}0.6\;kg$/8 weeks and $2.8{\pm}0.6\;kg$/8 weeks, respectively. However, the % of lean body mass (LBM) in men and women was shown to increase significantly (p<0.05). The daily intake of calorie, fat, protein, vitamin E, folate, and iron were significantly reduced during the LCD period. Blood levels of lipids and glucose were in normal range, and evidenced no changes after LCD. However, the serum levels of leptin in female subjects were significantly reduced (p<0.00l) from $8.9{\pm}4.8\;ng/mL$ to $6.9{\pm}4.8\;ng/mL$. In conclusion, 8 weeks of LCD with individualized counseling by a dietitian effectively reduced body fat and visceral fat in both men and women with BMI in excess of $23\;kg/m^2$.

• Journal of Korean Medicine Rehabilitation
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• v.18 no.2
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• pp.143-156
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• 2008

목적 : 갱년기 여성은 내장비만의 위험이 높으며 또한 심리적 변화를 겪는 시기이다. 갱년기 여성의 복부지방, 내장지방, 피하지방 및 이와 관련된 단순비만지표, 간울증, 스트레스, 우울, 자존감 등을 조사하여 갱년기 건강의 위협이 되는 신체 심리 인자를 알아보고자 이 연구를 시행하였다. 방법 : 병원공고를 통해 체질량지수 $23kg/m^2$ 이상 비흡연자인 만 45세 이상 55세 이하의 폐경 전후의 갱년기 여성 환자를 모집하여 2007년 8월 20일부터 24일까지 47명이 모집되었으며 이중 체질량지수 $25kg/m^2$ 이상이면서 복부 전산화 단층촬영 상 내장지방이 $100cm^2$ 이상인 20명의 단순비만지표, 체성분검사, 혈액검사, 복부 전산화 단층촬영 및 한방비만변증 (간울) 및 스트레스, 우울, 자존감 설문검사 결과의 상관성을 분석하였다. 본 연구는 경희대학교 동서신의학병원의 임상연구심사위원회의 승인을 받았다. 결과 : 1. 갱년기 비만여성에서 복부지방 면적, 피하지방 면적은 체질량지수, 체지방률, 허리둘레/신장비 등의 단순비만지표와 유의한 상관성을 보인 반면 (p < 0.01), 내장지방 면적은 단순비만지표와 상관성을 보이지 않았다. 2. 내장지방 면적은 사회 재적응 평가척도 (${\gamma}=0.577$, p < 0.01)와 유의한 상관성이 있었고, 선형회귀분석에서 유의한 결과를 나타냈다. $VAT(cm^2)=116.1+0.101{\times}(SRRS\;score)$ (${\gamma}^2=0.332$) 3. 피하지방은 식이태도 점수와, 총복부지방은 식이태도 점수 및 갱년기지수 중 혈관운동증상과 상관성이 있었다. 4. 간울증은 스트레스 반응척도, 우울지수, 갱년기지수 및 그 하부항목 중 혈관운동, 정신, 운동, 소화, 전신증상과 양의 상관성을, 자존감척도와는 음의 상관성을 나타냈으며, 내장지방과 직접적인 상관성을 보이지 않았다. 결론 : 간울증은 높은 스트레스, 우울, 갱년기 증상 및 낮은 자존감과 관련되는 것으로 나타났다. 폐경전후 비만여성에서 내장지방 면적은 간울증과 유의한 상관성을 보이지 않았으나, 생활 스트레스 사건이 많을수록 높아지는 것으로 나타나 갱년기 여성 내장비만에서 스트레스에 대한 대처가 중요할 것으로 사료된다. 추후 임상적 연계성 및 설문 보완에 대한 연구가 필요하리라 생각된다.

• Environmental and Resource Economics Review
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• v.20 no.4
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• pp.827-858
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• 2011

In Korea, various environmentally harmful subsidies are granted in agriculture, fishery, energy, electricity, transportation, steel and shipbuilding industry. Examples include tax-exempt fuel for agriculture & fishery, VAT- exemption for briquette & anthracite, temporary subsidy for fuel, production stabilizing subsidy for coal mining, subsidy for briquette. Korea's yearly total subsidy in energy area is about 5,291 billion won, among them is 4,870 billion won. To reduce air pollutants and to mitigate climate change, Korea has to review the phase-out of environmentally harmful subsidies and the phase-in of environment-friendly subsidy. The reduction or removal of environmentally harmful subsidies will enhance economic efficiency and bring about environmental benefits. Economic efficiency means less use of inputs, which reduces environmental cost and improves social benefits. This paper applies the Shoven and Whalley's model to the Korean economy and analyzes the general equilibrium incidence effects of reforming environmentally harmful subsidies in the energy and electricity in Korea. We consider several counterfactual scenarios in which current environmentally harmful subsidies are reduced or abolished, compare them with the reference case in the economy, and evaluated the change in efficiency costs and distributional incidence of tax reforms related to subsidies.

• Biomolecules & Therapeutics
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• v.14 no.4
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• pp.226-234
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• 2006

Disturbance of antioxidant system is very common in chronic alcoholics and herbal or natural products with antioxidant activity have been used for its treatment. This study was to investigate the effect of Vitis vinifera extract(V), Schisandra chinensis extract(S), Taraxacum officinale extract(T), Gardenia jasminoides extract(G), Angelica acutiloba extract(A) and Paeonia japonica extract(P), and their combinations on the antioxidant and ethanol oxidation system. Male Sprague-Dawley rats were subjected to Lieber-DeCarli ethanol liquid diet(ED) and were then given different herbal extract mixtures for 6 weeks including VST(V 100+S 150+T 150mg/kg/day), VSG(V 100+S 150+G 150mg/kg/day), VTG(V 100+T 150+G 150mg/kg/day), and VAP(V 100+A 150+P 150mg/kg/day). When the activity of alcohol dehydrogenase(ADH) and acetaldehyde dehydrogenase(ALDH) were compared between ED only group and herbal extracts treatment group, the differences were statistically significant. Phase I and II(glutathione-S-transferase, phenol sulfatransferase) enzyme activities were found to be significantly higher in the VAT treatment group compared to the ED group. Herbal extracts not only repressed the ethanol-induced elevation of malondialdehyde level, but also protected against ethanol-induced decrease in glutathione content, glutathione reductase, glutathione peroxidase, catalase and superoxide dismutase activities. The administration of the herbal extracts was found to be effective in eliminating lipid-peroxides induced by long-term consumption of alcohol by activating various enzyme systems and physiological active compound formation system. After a chronic consumption of alcohol, Angelica Radix protected the liver via activating the ethanol-metabolism enzyme system, and Paeoniae Radix via activating the ethanol-metabolism enzyme and the phase I, II-metabolism enzyme system. Taraxaci Herba was also effective in liver protection via activating the ethanol-metabolism enzyme system and the phase I, II-metabolism enzyme system, Gardeniae Fructus via activating the phase II-metabolism enzyme system and the anti-oxidation system enzyme, and Schisandra Fructus and a grapestone via activating the anti-oxidation system. Our data suggest that these herbal extracts may be useful as a health functional food or new drug candidate for fatty liver and hepatotoxicity induced by chronic alcohol consumption.

• Journal of Korean Society of Transportation
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• v.23 no.2
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• pp.107-116
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• 2005

The information on travel time in providing the information of traffic to drivers is one of the most important data to control a traffic congestion efficiently. Especially, this information is the major element of route choice of drivers, and based on the premise that it has the high degree of confidence in real situation. This study developed a vehicle arrival time prediction algorithm called as "VAT-DV" for 6 corridors in total 6.1Km of "Nam-san area trffic information system" in order to give an information of congestion to drivers using VMS, ARS, and WEB. The spatial scope of this study is 2.5km~3km sections of each corridor, but there are various situations of traffic flow in a short period because they have signalized intersections in a departure point and an arrival point of each corridor, so they have almost characteristics of interrupted and uninterrupted traffic flow. The algorithm uses the information on a demand volume and a queue length. The demand volume is estimated from density of each points based on the Greenburg model, and the queue length is from the density and speed of each point. In order to settle the variation of the unit time, the result of this algorithm is strategically regulated by importing the AVI(Automatic Vehicle Identification), one of the number plate matching methods. In this study, the AVI travel time information is composed by Hybrid Model in order to use it as the basic parameter to make one travel time in a day using ILD to classify the characteristics of the traffic flow along the queue length. According to the result of this study, in congestion situation, this algorithm has about more than 84% degree of accuracy. Specially, the result of providing the information of "Nam-san area traffic information system" shows that 72.6% of drivers are available.

• Industry Promotion Research
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• v.6 no.2
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• pp.1-10
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• 2021

The content of the information age does not simply convey content but includes all the transactions that arise from its interaction. The types and forms of information being traded through this interaction are recognized differently from the contents that have been passed on to mankind so far by creating new meaningful content. Because the distribution of interactive content transcending the concept of time-to-time in the network environment is an important component of access to added value in the new world, unlike the content of simple concepts seen in the products of communication so far. In this study, the purpose of this study is to recognize the current status and problems of the Korean digital content industry and to seek ways to revitalize the Korean digital content industry to lead the global market in the future. Specifically, first, we want to learn about the concept of digital content. Second, we would like to look at the industrial trends of digital content at home and abroad. Third, we present a plan to streamline digital content. Fourth, derive research results and implications. In this work, the following results are derived: First, in order for Korea to enter a digital content powerhouse, each government department must first break away from the selfishness of the ministry and actively cooperate to efficiently establish and implement various policies. Second, e-books should be introduced just as current paper and CD-ROM titles are exempt from VAT, and security solutions, related technology development, and copyright issues should be urgently addressed to revitalize the market. Third, the demand for high-quality content should increase as information infrastructure such as high-speed information and communication networks and satellite broadcasting is established.