• Economic and Environmental Geology
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• v.38 no.1
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• pp.1-22
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• 2005

Carbon dioxide ($CO_2$) is the greatest contributor among the major greenhouse gases covered by the Kyoto Protocol. Therefore, substantial efforts for the control and reduction of $CO_2$ emissions, including increased efficiency of fossil fuel energy usage, development of energy sources with lower carbon content, and increased reliability on alternative energy sources, are being performed worldwide. However, development and industrial application of $CO_2$ sequestration techniques are needed to meet the requirements of the Kyoto Protocol. Among the $CO_2$ sequestration methods developed, geological sequestration methods such as the storage in deep aquifers, deep coal seams and oil and gas reservoirs and the mineral carbonation is considered most favorable because of its stability and environmental effectiveness. In this review, geochemical concepts and technologic development of geologic sequestration technology, especially the storage in deep aquifers and the mineral carbonation, are discussed. The weakness and strengths for each of geologic sequestration methods, are also reviewed.

• Resources Recycling
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• v.29 no.6
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• pp.88-97
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• 2020

In this study, the selected waste plastic waste logistics used for cement sintering were classified into two types through the process of sorting and crushing, analyzing the characteristics of each, and analyzing the correlation of the strength after cement manufacturing. The experimental variables were classified into soft and hard waste plastic waste, and the correlations between calorific value, chlorine, and moisture were analyzed. In addition, some of each waste was selected and melted, and the basic characteristics were evaluated by analyzing the structure and calorific value. The results of the experiment showed that it was evaluated that it is suitable to obtain a heat source by separating soft waste plastic wastes and sintering them with materials having similar properties. As a result of examining the wastes by strength after cement manufacturing, it was analyzed that the use of hard plastics greatly contributes to the compressive strength on the 1st and 28th, and the use of soft plastics contributes to the compressive strength on the 28th. However, these characteristics are evaluated by collecting only a part of the waste, and since the deviation of the waste occurs, continuous management is required, and a follow-up study on the environmental problems caused by the use of waste is required.

• Korean Journal of Poultry Science
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• v.47 no.4
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• pp.275-283
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• 2020

This experiment was conducted to investigate the effect of the addition of enzymes and microorganisms to broiler feed on productivity, carcass characteristics, intestinal microflora, and feces odor. A total of one-hundred eighty 180 chicks (Ross 308) were randomly assigned to 5 treatments with 3 replications each having 12 birds per pen. The experimental group was divided into 0.1% EZ group (0.1% metallo-protease added to the feed), 0.2% EZ group (0.2% metallo-protease added to the feed), M group (2.0% Bacillus veleznesis CE 100 added to the feed), and MW group (2.0% Bacillus veleznesis CE 100 added to the feed and drinking water). In the results, final body weight, body weight gain, the feed conversion ratio, protein efficiency, and energy efficiency were not significantly different among all treatments in across all periods. Carcass weight, proventriculus, gizzard, heart, small intestine, cecum, and rectum weight were not significantly different among all of the treatments. However the liver weight was significantly higher in the 0.1% EZ group than in the control, M and MW groups (P< 0.05). E. coli was significantly lower in MW than in the control and M (P<0.05), and it was significantly higher in the M than 0.2% EZ and MW (P<0.05). H2S emissions in feces was not significantly different among all treatments, but NH3 emissions was were significantly higher in 0.1% EZ than in MW (P<0.05). In conclusion, the addition of 0.1% of metallo-protease was effective in the development of the liver of broilers.

• Journal of Korea Multimedia Society
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• v.11 no.5
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• pp.685-691
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• 2008

Recently with the rapid evolution of the mobile computing and communication technologies, mobile VOD service becomes increasingly important for wireless mobile users. The VOD service is being widely used in various areas of application, such as education, entertainment and business, because it provides users convenience in easily having access to video information at any time in any places. However, in reality, the mobile system has many difficulties in providing the smooth VOD service owing to frequent transfers and cutoffs of clients. The importance of a technique to transmit broadcasting is being stressed as a method for providing stabler mobile VOD service to a large number of clients. This paper is aimed at showing how to reduce demands for server bandwidth and delay of earlier service through performance analysis by suggesting an effective VOD broadcasting transmission technique through channel division in the mobile atmosphere. Many researches have been made about regular broadcasting techniques in particular. This study divides the methods used for assigning channels which have been decided by the size of segments into a group of regular channels and assistant channels using wireless gap-fillers to provide effective VOD services to a large number of clients at the mobile environment using small bandwidth resources. The regular channels transfer regular streams, while assistant channels repeatedly transfer the first segment to reduce early service delay time to receive regular streams. In this way, the study suggests a technique to reduce server bandwidth demand and early service delay time. Through the proposed technique, the server bandwidth demand could be reduced by more than 30 percent and the study continuously shows reduced early service delay time through conducting performance analysis.

• Journal of IKEEE
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• v.9 no.2 s.17
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• pp.123-135
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• 2005

3GPP RLC protocol specification adopted a window-controlled selective-repeat ARQ scheme for provisioning reliable data transmission. Inevitably, the re-ordering issue arises in the 3GPP's ARQ since it belongs to the selective-repeat ARQ clan. A long re-ordering time results in the degradation of throughput and delay performance, and may invoke the overflow of the re-ordering buffer. Also, the re-ordering time must be regulated to meet the requirements of some services which are both loss-sensitive and delay-sensitive. In the 3GPP's ARQ, we may deflate the occupancy of the re-ordering buffer by reducing the window size and/or length of the status report period. Such a decrease, however, deteriorates the throughput and delay performance and encroaches the resource of the reverse channel. Aiming at reducing the occupancy at the re-ordering buffer while suppressing the degradation of throughput and delay performance, we propose threshold-dependent occupancy control schemes, identified as post-threshold and pre-threshold schemes, as supplements to the 3GPP's ARQ. For judging the effectiveness of the proposed schemes, we investigate peak occupancy, maximum throughput and average delay in the practical environment involving fading channels. From the simulation results, we observe that the proposed schemes invoke the performance trade-off between occupancy and throughput in general. Also, we reveal that the post-threshold scheme is able to improve the throughput and delay performance of the ordinary 3GPP's ARQ without inflating the occupancy of the re-ordering buffer.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.2
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• pp.212-219
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• 2019

This study was conducted to investigate marine algal community characteristics and the status of barren ground in the summer at study sites on Jeju Island, Korea. Sampling was carried out from July to September 2017 using a qualitative and quantitative survey (including coverage of non-geniculated coralline algae and density of grazer) by scuba diving. A total of 121 species were identified, including 11 (9.1 %) green algae, 24 (19.8 %) brown algae, and 86 (71.1 %) red algae. Hyeongjeseom had the greatest diversity, with 60 species, and Harye the least, with 18 species. The mean biomass at the study sites was $1,503.0g{\cdot}m^{-2}$, while the mean for the neighboring islets ($3,268.7g{\cdot}m^{-2}$) was higher than that of the main island ($914.7g{\cdot}m^{-2}$). Also, dominant species was identified: Sargassum macrocarpum at the neighboring islets, and Ecklonia cava at the main island, with differences showing not only in biomass but also species composition. In conclusion, the marine algal community status in summer at the study sites was evaluated based on the algal community characteristics (species composition, biomass, biomass ratio of kelp species), coverage of non-geniculated coralline algae, and density of grazer. As a result, both Hyeongjeseom and Marado require preservation and management to maintain their excellent marine algal communities, and other sites on the main island require the creation and/or restoration of marine algal communities. In addition, as the generation of barren ground accelerates, it is urgent not only to grasp existing monitoring research but also to identify the status of the marine algal community where it is not known at present.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.127-133
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• 2012

In this paper, tests were carried out to monitor the effect of the curing temperature on autogenous shrinkage of the high strength cement mortar incorporating silica fume, blast furnace slag and fly ash ranged from 10%~30% by mass of cement. The curing temperatures were varied from $5^{\circ}C$ to $35^{\circ}C$, respectively. According to results, the setting time exhibited to delay with increase of admixture and drop of temperature. As for the effect of curing temperature on autogenous shrinkage, the increase of SF and BS resulted in an increase of autogenous shrinkage, while the use of FA decrease. The higher the curing temperature is, the greater the autogenous shrinkage is. This is due to the accelerated hydration rate of cement. It is found that the maturity does not consider the effect of curing temperature on autogenous shrinkage.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.572-578
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• 2009

This paper introduce a structure of haptic collaboration system over high resolution tiled-display, and proposes a object based efficient display method for high resolution display in integrated system. in addition, a modeling of visualization system is defined to evaluate performance of the proposed method. Both haptic system and tiled-display system have requirements of computational power. A haptic device is unstable if haptic rendering rate is less than 1kHz. A requirement of tiled-display systems is frame rate of display. It requires update of 30 frame fer sec. If we use these systems independently, we can satisfy each requirements. However, if we integrate two systems, performance of entire system significantly decreases because of lack of resources. In this paper, therefore, we propose a segmentation-based display method for ultra high resolution display in integrated system. The proposed method reduces redundancy of display data by reducing a display rate of static objects. Finally, a modeling of visualization system is defined to evaluate performance of the proposed method.

• Journal of the Korea Computer Industry Society
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• v.2 no.4
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• pp.455-470
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• 2001

This paper is focused on the traffic characterization for the efficient transmission of the VBR video source in the ATM network. For the traffic characterization, low traffic monitoring technique is applied and the dynamic VBR characterization method is suggested to satisfy the delay requirement. The dynamic VBR method uses the token bucket algorithm buffering though Cumulative Constraint Function. According to the Cumulative Constraint Function, the packet initially started transferring at the peak rate and the token bucket provided proper amount of buffer for traffic after a certain period of monitoring. It also reduced the network resource bandwidth through renewal of the cumulative frame and changed the rate from the previous frame information. It requires only small amount of monitoring and causes little overhead. In addition, it lowered the complexity of Deterministic Constraint Function to 0(n) and mapped the token rate and token depth to the token bucket. This study shows less network resource consumed than the previous method, comparing and analyzing the result of simulations.

• Proceedings of the Korean Society of Community Living Science Conference
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• 2009.09a
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• pp.100-100
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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 강릉시 지역의 자연마을 지명유래, 이미지, 관광자원 등을 조사하였다. 강릉시의 자연마을 유래 233건에 대한 자료는 국토지리정보원, 문화원자료집, 강릉시 홈페이지, 산, 강, 골, 고적, 못 등 그 외 지명자료는 한글학회 지명총람에서 1,147건을 수집하였다. 자연마을지명의 유래 233건을 8개 유형으로 구분하면 자연지리 60건, 인문지리 40건, 생태환경 37건, 산업경제 14건, 역사 14건, 유적유물 5건, 민속 49, 종교 14건이며, 지형(27건), 풍수(19건), 고사(19건)관련 유래가 많았다. 강릉시 지역브랜드 개발을 위한 요구도 조사는 지역민 162명과 방문객 154명 총 316명을 조사하여 SPSS WIN 12.0 프로그램을 이용 분석하였다. 응답자의 일반적인 특성은 남성이 50.6%, 대졸자가 54.1%, 연령은 40대(26.9%), 1500만원-3000만원 미만의 연소득자 32.3%가 가장 많았다. 강릉시의 형용사적 이미지를 기술통계량으로 살펴보면 지역민은 전통적인, 평화로운, 보수적인, 순수한, 따뜻한 순으로, 방문객은 순수한, 평화로운, 활기찬, 전통적인, 정감있는 순으로 평균값이 높게 나타났고, 요인분석에 의한 지역민과 방문객의 인지적 형용사 도출결과는 진취적, 평화적, 보수적인 3가지 요인이다. 또한 강릉의 대표적 상징자원은 지역민은 경포대(60.5%), 선교장(24.7%), 오죽헌(23.5%)순이며, 방문객은 경포대(74.7%), 정동진(22.7%), 오죽헌(18.8%) 순으로 높게 응답하였고, 지명 호감도는 지역민의 경우 송림(51.2%), 몽룡실(32.1%), 연화장터(18.5%)순이며, 방문객의 경우 송림(43.5%), 솔밭말(23.4%), 금단이(18.2%)순으로 높았다. 향후 본 연구에서 제시된 연구를 통하여 강릉시의 지명을 활용한 브랜드개성을 측정할 수 있어 마케팅 관점에서 강릉시의 브랜드를 도출하는데 기여할 수 있을 것이다.