• Korean Chemical Engineering Research
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• v.47 no.1
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• pp.127-132
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• 2009

This report examines the economic feasibility of a commercial 50,000 barrel per day direct coal liquefaction(DCL) facility to produce commercial-grade diesel and naphtha liquids from medium-sulfur bituminous coal. The scope of the study includes capital and operating cost estimates, sensitivity analysis and a comparative financial analysis. Based on plant capacity of 50,000BPD, employing Illinois #6 bituminous coal as feed coal the total capital cost appeared $3,994,858,000. Also, the internal rate of return of DCL appeared 6.60% on the base condition. In this case, coal price and sale price of products were the most influence factors. And DCL's payback period demanded a long time(12.3 years), because of high coal price at the present time. According to sensitivity analyses, the important factors on DCL processes were product sale price, feed coal price and the capital cost in order.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.2 s.314
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• pp.27-36
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• 2007

Changeable biometrics identify a person using transformed biometric data instead of original biometric data in order to enhance privacy and security in biometrics when biometric data is compromised. In this paper, a novel scheme which generates changeable face templates for statistical appearance-based face recognition is proposed. Two different original face feature vectors are extracted from two different appearance-based approaches, respectively, each original feature vector is normalized, and its elements are re-ordered. Finally a changeable face template is generated by weighted addition between two normalized and scrambled feature vectors. Since the two feature vectors are combined into one by a two to one mapping, the original two feature vectors are not easily recovered from the changeable face template even if the combining rule is known. Also, when we need to make new changeable face template for a person, we change the re-ordering rule for the person and make a new feature vector for the person. Therefore, the security and privacy in biometric system can be enhanced by using the proposed changeable face templates. In our experiments, we analyze the proposed method with respect to performance and security using an AR-face database.

• Journal of the Korean GEO-environmental Society
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• v.6 no.1
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• pp.15-21
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• 2005

In this study, the utilization of coal-ash and phosphogypsum was considered as the evapotranspiration final landfill cover(ET cover) material. Cover material considered was the mixture of the weathered granite soil, coal-ash and phosphogypsum and so we sequentially performed the leaching test, column test and field model test to investigate the environmental effects of mixtures of coal-ash and phosphogypsum. In the leaching test, all materials had lower heavy metal concentration than the regulated threshold values. The column test and the review of related regulations were carried out to determine the optimum mixing ratio(OMR) and OMR was soil(4):coal-ash(1): phosphogypsum(1) on the volume base, which was applied to field model test. Field model tests were continued from February to June, 2004 in the soil box that was constructed with cement block. It was verified that coal-ash and phospogypsum mixed with soil was safe environmentally and the mixture of both wastes could improve the water retention capacity of cover materials.

• The Korean Journal of Pesticide Science
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• v.18 no.1
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• pp.8-13
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• 2014

This study evaluated in vitro cytotoxicity of 5 pesticides, including 2 herbicides, 2 germicides, and an insecticide, as an alternative to the fish acute toxicity test. The in vitro cytotoxicity was tested using a neutral red uptake (NRU) assay with epithelioma papulosum cyprini (EPC) cells that originated from the epidermal tissue of Cyprinus carpio (common carp). An in vivo fish acute toxicity test was conducted according to OECD Test Guideline No. 203 using Aphyocypris chinensis (Chinese bleak), Oryzias latipes (Japanese medaka), and C. carpio. The results showed that the sensitivity of the cell viability assay for the pesticides was similar to the fish acute test in ranking order despite having approximately 10 times less absolute sensitivity. The $r^2$ correlation values were calculated as 0.38 (p = 0.26), 0.76 (p = 0.05) and 0.90 (p = 0.01) for A. chinensis, O. latipes, and C. carpio, respectively. These results suggested that the potential of EPC cell viability assay as an alternative to the fish acute toxicity test due to their good correlation and NRU assay is expected to serve as a useful tool for predicting acute fish lethality for pesticides if further studies with a large set of pesticides are conducted.

• Economic and Environmental Geology
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• v.48 no.3
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• pp.261-271
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• 2015

Toxicity results of metals, nanoparticles (NPs), and soils contaminated with metals were introduced on this review. Following methods were used: seed germination, bioluminescence, enzyme activity, and mutation. In general, different sensitivities were observed, depending on types of bioassays and pollutants. Among tested seeds, sensitivities of Lactucus and Raphanus were greater than others. Of single metal exposure, effect by As(III) was greater than others, and high revertant mutation ratio (5.1) was observed at 1 mg/L arsenite, indicating high mutagenicity. No general pattern was observed on the effect of metal mixture, but synergistic effect was observed with seeds. In case of soils, no correlation was observed between total metal contents and toxicity. Toxicity of NPs was observed as follows: CuO > ZnO > NiO > $TiO_2$, $Fe_2O_3$, $Co_3O_4$. Especially, no considerable effects were observed by $TiO_2$, $Fe_2O_3$, and $Co_3O_4$ under tested concentration (max. 1,000 mg/L). The evaluation results of interactive toxic effects using various bioassays may comprise a useful tool for the bioassessment of various environmental pollutants.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.3
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• pp.171-180
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• 2013

Even though styrofoam buoys represent a large portion of beached marine debris in Korea, efficient government actions have been lacking to address them. Three participatory workshops were organized from 2010 to 2012 to develop policy measures to manage styrofoam buoy marine debris. The first workshop held in 2010 was organized in order for workshop participants to understand and share the styrofoam debris issue. Participating stakeholders suggested policy measures to address styrofoam debris through brainstorming in the second workshop in 2011. In the third workshop organized in 2012, the analytic hierarchy process (AHP) was used to set priorities for 16 selected policy measures. A total of 56 people participated in AHP, and answers of 40 participants that passed the consistency test were analyzed. 'Beach cleanup by public works program' ranked highest in priority, followed by 'Development of alternative buoy and aquaculture technologies'. Other research projects also ranked high in priority. Feasibility of policy measures was considered the most important criterion in the priority setting, followed by effectiveness, efficiency, and acceptability. This study demonstrated that participatory workshops in which diverse stakeholders take part in could provide a valuable tool in developing practical policy measures on styrofoam buoy marine debris.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.10
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• pp.551-557
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• 2015

This study analyzes potentially hazardous sub-watersheds from non-point source pollution areas using an HSPF model. The watershed of the Juam dam reservoir was divided into 29 sub-watersheds, and the flow, BOD, TN and TP concentration for the Juam dam watershed were evaluated from 2009 to 2012 using a watershed model, with a warming period from 2009 to 2010. The results of the watershed model agreed well with the flow and water quality field measurements. The calculated average non-point source loadings were BOD of 8.8 and $9.1kg/day/km^2$ in 2011 and 2012, respectively; TN of 9.7 and $10.1kg/day/km^2$ in 2011 and 2012, respectively; and TP of 0.30 and $0.33kg/day/km^2$ in 2011 and 2012, respectively. The non-point source loading of the Bonghwa stream watershed was calculated, and predominantly assessed upstream of the Boseong river. Additionally, the Miryeok, Jangpyeong, Yuleo, Guam, Seokgyo, Mundeok, Incheon, and Bongnae stream watersheds, with extensive agricultural areas, were assessed to be potentially hazardous areas in terms of non-point source management. In this study, HSPF model was applied in order to aid in the selection of non-point source reduction facilities for the Juam dam watershed, where they were evaluated as to whether they would be applicable for non-point source management.

• Food Science and Preservation
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• v.17 no.3
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• pp.418-424
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• 2010

Although the wine industry continues to grow, little empirical research on consumer preferences has been conducted. Thus, our objective was to analyze consumer views on wine attributes. A choice experiment (CE) was designed to detect a marginal willingness to pay for particular characteristics of wine (balance, flavor, color, clarity, and value-for-money). A questionnaire was administered and 286 responses were received. A multinomial logit model was estimated using the maximum likelihood method. The results indicated that balance, flavor, color, clarity, and price were all important to consumers. The CE data revealed that estimates of marginal willingness to pay were 31,899 won/bottle for balance, 23,088 won/bottle for flavor, 3,230 won/bottle for color, and 25,936 won/bottle for clarity. The balance of a wine was most important, and the flavor, clarity, and color were also significant. The results of this work will be of assistance in promoting the domestic wine industry.

• Journal of Korean Society of Transportation
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• v.28 no.4
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• pp.61-73
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• 2010

This research is to analyze reasons for violation of the Self Carfree day policy. It also analyzes satisfaction of the policy participation incentives. The results are that the violation rate is increasing if the drivers live in a zone which is highly energy consuming, which has low potential demand per bus stop and low trip generation per number of houses, which therefore requires more bus routes and bus services, and in which the drivers pay more car operating fees and show less tendancy towards participation even with the 5-10% oil price increase. The results are significant at the 0.05 level.

• Journal of the HCI Society of Korea
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• v.1 no.1
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• pp.29-36
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• 2006

Tactile displays can provide useful information without disturbing others and are particularly useful for people with visual or auditory impairments. They can also complement other displays. In this paper, we present a new vibrotactile display device for wearable, mobile, and ubiquitous computing environments. The proposed vibrotactile device has a $5{\times}5$ array configuration for displaying complex information such as letters, numbers, and haptic patterns as well as simple directional ques and situation awareness alarms. Commercially available coin-type vibration motors are embedded vertically in flexible mounting pads in order to best localize vibrations on the skin. An embedded microprocessor controls the motors sequentially with an advanced tracing mode to increase recognition rate. User studies with the vibrotactile device on the top of the foot show 86.7% recognition rate for alphabet characters after some training. In addition, applying vibrotactile device to driving situation shows 83.9% recognition rate. We also propose some potentially useful application scenarios including Caller Identification for mobile phones and Navigation Aids for GPS systems while driving.