• Resources Recycling
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• v.28 no.6
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• pp.3-8
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• 2019

Recently, plastic waste in Korea has been recognized as a critical issue due to an increase in massive production of plastics, difficulty in disposal of waste plastics, and public recognition of toxicity in micro-plastics, etc. To resolve those problems, the regulation to reduce plastics consumption may be primarily considered but, in this case, clarification should be made on the rationales and the action plans in the regulation for individual waste plastic items. Another problem is the small capital sizes of domestic recycling companies, which leads to poor R&D capacity, low recycling yields and thus lowering values of recycling items. This adversely affects consumers' perception. The R&D toward recycling technical progress should take into account the environmental friendliness and recyclability from the early product design stages. Certainly, this should be supported in governmental policy and public action plans. In addition, by referring to advanced policies of i.e. European Union, the recycling industry should be recognized as an opportunity toward new investment & employment. If necessary, the regulation of plastic consumption through a formal evaluation process such as Life Cycle Assessment (LCA) will also be helpful. The values of recycled plastics should be improved through the identification and elimination of harmful chemical substances potentially contained in the products.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.2
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• pp.105-115
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• 2010

In this study, as one of solutions associated with the shortage of treatment area of industrial waste and the containment of its harmful components, the bottom ash which is known to be by-products of thermoelectric power plant was selected and its applicability for aggregate of concrete mixture was measured. Hardness test, sieve analysis, water-absorption test and SEM analysis were carried out to investigate the possibility of using bottom ash as a replacement of coarse and fine aggregate. Chemical analyses such as ignition loss test and X-ray incidence were carried out also. In addition, values for slump, strength, permeability, freeze and thaw, and carbonation were evaluated in terms of effects of replacement ratio of bottom ash. As the results, it was found that, though bottom ash is in short supply of fine particles and is in lack of cohesion, these problems can be solved by partially mixing with natural aggregates or improving in a process of production. In addition, bottom ash has not only advantage of durability but also acquirement of general compressive strengths in case that a certain proportion of natural aggregate is applied to mixture, in spite that unit water or chemical admixture should be increased to acquire good workability due to plenty of porosity.

• Resources Recycling
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• v.21 no.5
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• pp.79-87
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• 2012

With the increasing size and universalization of lithium-ion batteries, the development of cathode materials has emerged as a critical issue. The energy density of 18650 cylindrical batteries had more than doubled from 230 Wh/l in 1991 to 500 Wh/l in 2005. The energy capacity of most products ranges from 450 to 500Wh/l or from 150 to 190 Wh/kg. Product developments are focusing on high capacity, safety, saved production cost, and long life. As Co is expensive among the cathode active materials $LiCoO_2$, to increase energy capacity while decreasing the use of Co, composites such as $LiMn_2O_4$, $LiCo_{1/3}N_{i1/3}Mn_{1/3}O_2$, $LiNi_{0.8}Co_{0.15}Al_{0.05}O_2$, and $LiFePO_4$-C (167 mA/g) are being developed. Furthermore, many studies are being conducted to improve the performance of battery materials to meet the requirement of large capacity output density such as 500Wh/kg for electric bicycles, 1,500Wh/kg for electric tools, and 4,000~5,000Wh/kg for EV and PHEV. As new cathodes active materials with high energy capacity such as graphene-sulfur composite cathode materials with 600 Ah/kg and the molecular cluster for secondary battery with 320 Ah/kg are being developed these days, their commercializations are highly anticipated.

• Economic and Environmental Geology
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• v.50 no.2
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• pp.145-157
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• 2017

Because of Recent intensive rainfall, nationally landslides and slope failure phenomenon has been frequently occur. Providing proposed-measures to the natural disasters that occur in these localities and the slope, must be derived ground of strength parameters(shear strength) as a design input data. However, it is such as extra deforestation and a lot of economic costs in order to make the access to the current area and the slopes ground survey is required. Thus, by small dynamic cone penetration test machine using the human to carry in the field, it is possible to easily measure the characteristics and strength constant of the ground of more than one region. In this study through researching analysis of the domestic and foreign small dynamic cone penetration test method, it has proposed a cone material and test methods suitable for the country. Cone penetration test Nc in the field has comparated with analysis of the value and the standard penetration test N value. And, in addition to this, direct shear test and borehole shear test were performed by depth, bedrock, and soil type and passing #200 and the correlation of the Nc value. In particular, in the present study, for the sandy soil that has distict distribute in mountain, it is proposed relation of shear strength corresponding to the Nc value (cohesion and internal friction angle) in order to calculate such effective ground shear strength.

• Korean Journal of Plant Resources
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• v.33 no.1
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• pp.1-14
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• 2020

This study was conducted to analyze community structure and species composition of Pinus densiflora for. erecta Stand in Mt. Cheonchuk (653 m). Field survey was carried out from June to September in 2013. 74 plots (20×20 m) were set up, 5 herb layer plots (3×3 m) were constructed for each plot, and there, Diameter at Breast Heigh t(DBH), height, environmental factor, annual growth were measured. Vascular plants were surveyed as following; 66 family, 165 genus, 211 species, 2 sub species, 29 variety, 6 form 248 taxa. Results of cluster analysis for P. densiflora for. erecta forest, 3 communities were divided into; Quercus mongolica (P-1), Quercus variabilis (P-2) and Quercus aliena-Stephanandra incisa (P-3). There were significant environmental factors that organic layer, annual growth, CEC, total total nitrogen, organic matter and pH for each community. As a result of DCA, P-1 and P-2 were distributed large range of environmental factors but relatively limited in P-3. Distributions of herb layer were affected by sand, cation exchange capacity, silt and total nitrogen. Results of MRPP test for herb layer communities, it was significantly analyzed (A=0.003, P<0.008). Species diversity index was highly recorded in P-3 and influenced by cation exchange capacity, total nitrogen, annual growth in consequence of NMS analysis.

• Proceedings of the Korean Society of Community Living Science Conference
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• 2009.09a
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• pp.99-99
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• 2009

지명(地名)은 그 지역의 역사와 전설, 문화, 풍속은 물론 독특한 자연환경이나 생활 모습을 담고 있어 농업농촌의 지역적 특성을 나타낸다. 본 연구는 지명유래의 활용성 증진의 한 방편으로 브랜드 및 문화관광상품 개발을 위해 서천군의 자연마을 지명유래, 이미지, 관광자원 등을 조사하였다. 서천군의 자연마을 유래 516건에 대한 자료는 국토지리정보원, 문화원자료집, 서천군홈페이지에서, 산, 강, 골, 고적, 못 등 그 외 지명자료는 한글학회 지명총람에서 2,000건을 수집하였다. 자연마을지명의 유래 516건을 8개 유형으로 구분하면 자연지리 122건, 인문지리 114건, 생태환경 51건, 산업경제 25건, 역사 34건, 유적유물 28건, 민속 37건, 종교 19건이며, 지형(80건), 생물(33건), 고사(19건)관련 유래가 많았다. 서천군 지역브랜드 개발을 위한 요구도 조사는 지역민 154명과 방문객 152명 총 306명을 조사하여 SPSS WIN 12.0 프로그램을 이용 분석하였다. 응답자의 일반적 특성은 여성이 55.6%, 대졸자 54.2%, 연령은 40대(29.1%), 1500만원-3000만원 미만의 연소득자 32.0%가 가장 많았다. 서천군의 형용사적 이미지를 기술통계량으로 살펴보면 지역민은 평화로운, 정감있는, 순수한, 전통적인, 믿을수 있는 순으로, 방문객은 순수한, 평화로운, 정감있는, 따뜻한, 친절한 순으로 평균간이 높게 나타났고, 요인분석에 의한 지역민과 방문객의 인지적 형용사 도출결과는 정열적, 평화적, 보수적인 3가지 요인이다. 또한 서천군의 대표적 상징자원은 지역민의 경우 춘장대해수욕장(32.5%), 희리산 자연휴양림(16.9%), 금강하구둑 철새도래지(16.9%)순이며, 방문객은 춘장대해수욕장(43.4%), 희리산 자연휴양림(23.0%), 한산모시축제(23.0%)순으로 높게 나타났고, 지명 호감도는 지역민의 경우 꽃뫼(29.2%), 솔리(20.8%). 소야(17.5%)순이며, 방문객은 꽃뫼(30.9%), 솔리 (19.7%), 무닛골(16.4%)순으로 높았다. 향후 본 연구에서 제시된 연구를 통하여 서천군의 지명을 활용한 브랜드개성을 측정할 수 있어 마케팅 관점에서 서천군의 브랜드를 도출하는데 기여할 수 있을 것이다.

• The KIPS Transactions:PartC
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• v.11C no.1
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• pp.47-54
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• 2004

The growth of computer resource and network speed has increased requests for the use of remotely located computer systems by connecting through computer networks. This phenomenon has hoisted research activities for application service provision that uses server-based remote computing paradigm. The server-based remote computing paradigm has been developed as the ASP (Application Service Provision) model, which provides remote users through application sharing protocol to application programs. Security requirement such as confidentiality, availability, integrity should be satisfied to provide ASP service using centralized computing system. Existing Telnet or FTP service for a remote computing systems have satisfied security requirement by a simple access control to files and/or data. But windows-based centralized computing system is vulnerable to confidentiality, availability, integrity where many users use the same application program installed in the same computer. In other words, the computing system needs detailed security level for each user different from others, such that only authorized user or group of users can run some specific functional commands for the program. In this paper, we propose windows based centralized computing system that sets security policies for each user for the use of instructions of the application programs, and performs access control to the instructions based on the security policies. The system monitors all user messages which are executed through graphical user interface by the users connecting to the system. Ail Instructions, i.e. messages, for the application program are now passed to authorization process that decides if an Instruction is delivered to the application program based on the pre-defined security polices. This system can be used as security clearance for each user for the shared computing resource as well as shared application programs.

• Economic and Environmental Geology
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• v.43 no.2
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• pp.149-162
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• 2010

The most serious problem in oil stockpiles with artificial underground cavern is maintaining the stability of ground water system. In order to understand the ground water system around K-1 site, we determined the regional flow direction and level distribution of groundwater, and investigated the major geologic factors influencing their flow system. Reactivated surface along the contact between granite and gneiss, and fractures and faults along the long acidic dyke may contribute as important pathways for groundwater flow. Within K-1 site, groundwater level fluctuation is closely related to the rainfall events and injection from surface or influx water. In this project, the effect of groundwater pumping from the southern wells was examined. Based on equations relating water level drawdown to pumping rate at those wells, their pumped outflow of groundwater ranged from $80\;m^3$/day to less than $250\;m^3$/day. The modeling results with MODFLOW imply that the previous groundwater pumping at distance of 1.2 km may not affect the groundwater level variations of the K-1 site. However, continuous pumping work at quantity over $250\;m^3$/day in this area will be able to affect the groundwater system of the K-1 site, particularly along the acidic dyke.

• Korean Journal of Poultry Science
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• v.31 no.3
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• pp.145-150
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• 2004

Two experiments were conducted to evaluate the nutritional values of rice bran and to examine effects of its dietary supplementation on broiler performances. In the first experiment, true metabolizable energy(TME), nitrogen corrected true metabolizable energy(TMEn), and true amino acid availability(TAAA) values of the rice bran were determined by force-feeding sixteen roosters(ISA-Brown). In the second experiment, 3-week-old male broiler chickens(Avian) were divided into four groups and fed each one of four experimental diets containing 0, 5, 10 or 15% rice bran for 21 days. TME and TMEn values of the rice bran(dry matter basis) were 3.25 kcal/g and 3.12 kcal/g, respectively, and the average TAAA value of the 16 amino acids was 76.21%. The average feed intake and body weight gain of the birds fed diets containing rice bran were apparently greater than those of the control group although the differences were not significant statistically. From the results, it can be concluded that feed formulation using bioavailability values, such as TMEn and TAAA, is an effective method for protecting the high variation in growth performances and that rice bran can be used for broiler feeds to 15% without any significant negative effects.

• Clean Technology
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• v.18 no.3
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• pp.229-249
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• 2012

At present, global warming and depletion of fossil fuels have been one of the big issues which should be solved for sustainable development in the future. CCS (carbon capture and sequestration) technology as the post $CO_2$ reduction technology has been considered as a promising solution for global warming due to increased carbon emission. However, the environmental and ecological effects of CCS have drawn concerns. There are needs for noble post reduction technology. More recently, CCU (carbon capture and utilization) Technology, which emphasizes transforming carbon dioxide into value-added chemicals rather than storing it, has been attracted attentions in terms of preventing global warming and recycling the renewable carbon source. In this paper, various technologies developed for carbon dioxide conversion both in gas and liquid phase have been reviewed. For the thermochemical catalysis in gas phase, the development of the catalytic system which can be performed at mild condition and the separation and purification technology with low energy supply is required. For the photochemical conversion in liquid phase, efficient photosensitizers and photocatalysts should be developed, and the photoelectrochemical systems which can utilize solar and electric energy simultaneously are also in development for more efficient carbon dioxide conversion. The energy needed in CCU must be renewable or unutilized one. CCU will be a key connection technology between renewable energy and bio industry development.