• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.70-77
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• 2020

Microalgae are independent organisms that perform photosynthesis and can alter the culture environment to increase accumulation of useful substances derived from microalgae. In this study, cell growth was measured by incubation for 39 days using MBBM, Neo medium, and seven light sources, which is the main factor affecting cell growth of microalgae S. obliquus. In the case of S. oliquus, which grew in MBBM and Neo medium, cell growth was highest under fluorescent light sources and Red2 LED (R660) light sources, and cell growth was lowest under Infra Red LED (R741) light sources. The average cell growth rate was 17.7% for MBBM and 15.4% for Neo. Comparing the effects of dry cell weight of Neo medium containing nutrients on the production of aquatic plants, MBBM and dry cell weight of Neo resulted in higher cell growth than Neo medium under all LED light sources except for Blue LED (B450). This proves that MBBM is more suitable for increasing the cell growth of microalgae than Neo medium and confirms that light source selection is important in the production of useful materials through mass cultivation of microalgae in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.224-230
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• 2016

The purpose of this study was to examine the effects of height of the shoe heel in a one leg standing posture on the muscle activity of the rectus abdominis, erector spinae, hamstring, and rectus femoris. Twenty healthy female subjects were asked to perform a one leg standing posture with three types of shoes, which had different heights of shoe heel, 0cm, 3cm, and 7cm. Surface electromyography was used to evaluate the activities of the right rectus abdominis, erector spinae, hamstring, and rectus femoris muscles. The data was analyzed by repeated one-way ANOVA and the muscle activities among three heights of shoe heel were compared. The results showed that the muscle activities of the erector spinae and rectus femoris increased significantly according to increase height of shoe heel (p<0.05). The activity of the rectus abdominis and hamstring were not significantly different among the three height of shoe heel (p>0.05). These results suggest that the height of shoe heel affects the lumbo-pelvic alignment and center of mass; therefore, high-heeled shoes lead to musculoskeletal pain in the lumbopelvic, hip, and knee areas.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1032-1036
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• 2012

A bulking agent is an essential material for composting of high-moisture livestock manure such as pig slurry. Sawdust has been used as the most popular bulking agent but resources are limited in Korea. In this study, the feasibility of rice hull as a bulking agent was examined for composting of solid pig manure. The solid pig manure was mixed with 15% sawdust (PM+SD15), 15% rice hull (PM+RH15), 10% sawdust and 5% rice hull (PM+SD10+RH5), and 5% sawdust and 10% rice hull (PM+SD5+RH10) based on fresh weight. These mixtures were composted for 35 days. The average temperature of the composting file for 35 days was higher in PM+SD10+RH5 and PM+SD5+RH10 than in PM+SD15 and PM+RH15. The mass loss of PM+SD10+RH5 and PM+SD5+RH10 were 36.7 and 36.4%, respectively, which were higher than that of PM+SD15 and PM+RH15. After composting, organic matter content and organic matter/nitrogen ratio in all treatments met the official standards of commercial fertilizers. We concluded that rice hull may be a good bulking agent for pig manure composting when it is used in mixture with sawdust.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.1
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• pp.87-93
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• 2006

Inventories, and characteristics such as dimension, fuel rod array, weight, $^{235}U$ enrichment, and discharge burnup of spent nuclear fuel (SNF) generated from existing and planed nuclear power plants based on National 2nd Basic Plan for Electric Power Demand and Supply were investigated and projected to support geological disposal system design. The historical and projected inventory by the end 2057 is expected to be 20,500 and 14,800MTU for PWR and CANDU spent nuclear fuel, respectively. The quantity of SNF with initial $^{235}U$ enrichment of 4.5 wt.% and below was shown to be 96.5% in total. Average burnup of SNF revealed $\sim36$ GWD/MTU and $\sim40$ GWD/MTU for the period of 1994-1999 and 2000-2003, respectively. It is expected that the average burnup of SNF will be $\sim45$ GWD/MTU at the end of 2000's. From the comprehensive study, it was concluded that the imaginary SNF with $16\times16$ Korean Standard Fuel Assembly, cross section of $21.4cm\times21.4cm$, length of 453cm, mass of 672 kg, initial $^{235}U$ enrichment of 4.5 wt.%, discharge burnup of 55 GWD/MTU could cover almost all SNFs to be produced by 2057.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.1
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• pp.83-90
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• 2017

The pyroprocessing of spent nuclear fuel generates LiCl-KCl eutectic waste salt containing radioactive rare earth nuclides. It is necessary to develop a simple process for the treatment of LiCl-KCl eutectic waste in a hot-cell facility. In this study, capture and solidification of a rare earth nuclide (Nd) in LiCl-KCl eutectic salt using an inorganic composite with a $Li_2O-Al_2O_3-SiO_2-B_2O_3$ system was conducted to simplify the existing separation and solidification process of rare earth nuclides in LiCl-KCl eutectic waste salt from the pyroprocessing of spent nuclear fuel. More than 98wt% of Nd in LiCl-KCl eutectic salt was captured when the mass ratio of the composite was 0.67 over $NdCl_3$ in the eutectic salt. The content of $Nd_2O_3$ in the Nd captured-composite reached about 50wt%, and this composite was directly fabricated into a homogeneous and chemical resistant glass waste in a monolithic form. These results will be utilized in designing a process to simplify the existing separation and solidification process.

• Archives of design research
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• v.20 no.1 s.69
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• pp.167-176
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• 2007

As much time is being spent with the family at weekends by the development of leisure culture, many people have begun to enjoy camping in the field. While many people use pensions or camping cars, many families or groups of friends go on camping in the summer holiday season. Although the tent design in this country has gradually been developed, it is not as developed as overseas designs with unique design characteristics according to climate, cultural behavior and colors. In this research, the American and Korea tent designs are compared in terms of color and frame. The differences are analyzed and a direction for tent designs appropriate for Korea in terms of size, area, ease of carriage and installation is proposed through theoretical data and idea sketches. The frame weight has been minimized and the durability increased for the ease of carriage and installation. The style and number of windows have been increased in order to provide a comfortable space by understanding the influx of airflow and the size of the tent has also been increased to provide extra space for storage. The information on the overseas and domestic tent design trends led to a color comparison and the extraction of images of language. The tent based on the new design is currently being mass-produced in China following 3 months of preparation including sample making and testing.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.697-702
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• 2017

A preliminary study was carried out to investigate the feasibility of replacing honeycomb cores with pyramidal truss cores in the doors of urban transit railway vehicles. The doors in current operation are sandwich structures comprising a honeycomb core and reinforcements between two facesheets. The structural requirements of doors for urban transit vehicle are specified in the KRS and KRT and standards, according to which the deflections from three-point bending tests must be limited. To this end, two types of pyramidal truss cores with equivalent mass to a honeycomb core were designed. The structural stiffness of doors with pyramidal truss cores and honeycomb cores were numerically calculated via finite element analysis. The three-point bending models were constructed and simulated, and then the calculated deflections were compared with the requirements specified in the regulations. The results show that doors with pyramidal truss cores satisfied the stiffness requirements, although their deflections were 2.5% larger than that of the honeycomb cores. Therefore, the pyramidal truss cores could replace the aluminum honeycomb cores, and their multi-functional capability could be exploited.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.223-229
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• 2020

Biodiesel produced using microorganisms, which are recognized as the third-generation biomass, is among the various known renewable energy sources that can replace fossil fuels used in conventional transportation. Scenedesmus obliquus has been identified as an excellent species for biodiesel production, as it grows faster and can accumulate up to 40-50 percent of the dry cell weight. Enhancing production using S. obliquus requires measuring the cell mass for controlling the cultivation process. In the current study, S. obliquus was cultured for 75 days, and growth changes of the microalgae were measured by absorbance, microscopic imaging, and Raman spectroscopy. Between days 60 to 75 of culture, the change in absorbance was observed to be less than 3%, whereas the number of microalgae observed microscopically was more than three times higher. Moreover, the Raman spectroscopy results showed three strong peak values of β-carotene at 997 cm^-1, 1148 cm^-1, and 1515 cm^-1, with peak values of β-carotene showing greater than 3-fold increase during the culture period. Therefore, we predict that application of Raman spectroscopy will help in identifying the growth elements and growth degree in microalgae culture during increased biomass production.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.709-711
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• 2005

컴퓨터 그래픽스 분야의 발전으로 3D 모델의 수가 기하급수적으로 늘고 있다. 기존의 텍스트나 2D 이미지만을 검색하는 시스템으로는 정확한 3D 모델의 검색이 힘들다. 따라서 3D 모델 검색 시스템의 필요성이 대두되고 많은 분야에서 그 정확도와 속도향상을 위한 3D 모델 검색 연산자(Descriptor)와 검색 알고리즘을 개발하기 위한 연구가 진행 중이다. 본 논문에서는 VRML 모델을 XML 데이터로 변환하여 3D 모델 검색에 사용하는 것이 주요 목표이다. 검색 방법은 크게 VRML의 노드 분류화를 통한 기본 도형에 대한 검색과 XML로 변환하면서 생성하는 무게중심(Mass-Center)을 이용한 검색 두 가지이다. 즉, 3D 모델 데이터베이스를 구축함으로써 VRML 노드를 통한 분류화와 라벨화된 3D 모델 데이터베이스 지원 등의 장점을 활용한다. 3D 모델을 Key값(Descriptor)을 생성하여 분류화된 XML 데이터로 저장하고, 처리하여 유사도 비교의 대상과 횟수가 많아질수록, 3D 모델을 바로 데이터베이스에서 검색에 사용할 수 있어 검색의 속도와 성능을 보다 증가시킬 수 있다. 보다 복잡한 3D 모델의 유사도 비교에 있어서는 Princeton Shape Benchmark(PSB)[1]에서 정확도가 가장 높게 평가된 방법인 LFD(Light Field Descriptor)[6] 검색 연산자를 사용한다. 이 방법은 3D 모델에서 2D 이미지를 얻어 검색하는 방법으로 많은 2D 이미지 관측점(View-Point)과 관측된 2D 이미지의 적합도를 비교하는 계산량이 많은 단점이 있다. 그래서 3D 모델 검색을 위한 2D 이미지 관측에 있어 x, y, z축 방향의 관측점을 얻는 방법을 제안함으로써 2D 이미지의 관측점을 줄여 계산량을 대폭 감소시키는 장점을 갖는다.것으로 조사되었으며 40대 이상의 연령층은 점심비용으로 더 많은 지출을 하고 있는 것으로 나타났다. 4) 끼니별 한식에 대한 선호도는 아침식사의 경우가 가장 높았으며, 이는 40대와 50대에서 높게 나타났다. 점심 식사로 가장 선호되는 음식은 중식, 일식이었으며 저녁 식사에서 가장 선호되는 메뉴는 전 연령층에서 일식, 분식류 이었으며, 한식에 대한 선택 정도는 전 연령층에서 매우 낮게 나타났다. 5) 각 연령층에서 선호하는 한식에 대한 조사에서는 된장찌개가 전 연령층에서 가장 높은 선호도를 나타내었고, 김치는 40대 이상의 선호도가 30대보다 높게 나타났으며, 흥미롭게도 30세 이하의 선호도는 30대보다 높게 나타났다. 그 외에도 떡과 죽에 대한 선호도는 전 연령층에서 낮게 조사되었다. 장아찌류의 선호도는 전 연령대에서 낮았으며 특히 30세 이하에서 매우 낮게 조사되었다. 한식의 맛에 대한 만족도 조사에서는 연령이 올라갈수록 한식의 맛에 대한 만족도는 낮아지고 있었으나, 한식의 맛에 대한 만족도가 높을수록 양과 가격에 대한 만족도는 높은 경향을 나타내었다. 전반적으로 한식에 대한 선호도는 식사 때와 식사 목적에 따라 연령대 별로 다르게 나타나고 있으나, 선호도는 성별이나 세대에 관계없이 폭 넓은 선호도를 반영하고 있으며, 이는 대학생들을 대상으로 하는 연구 등에서도 나타난바 같다. 주 5일 근무제의 확산과 초 중 고생들의 토요일 휴무와 더불어 여행과 엔터테인먼트산업은 더욱 더 발전을 거듭하고 있으며, 외식은 여행과 여가 활동의 필수적인 요소로써 그 역할을 일조하고 있다. 이와 같은 여가시간의 증가는 독신자들에게는 좀더 많은 여유시간을 가족을 이루고 있는 가족구성원들에게는 가족과의 유대를 강화하는 휴식과 오락의 소비 트렌드를 창출시켰다. 이와 더불어 외식은 식사를 해결하기 위한

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.3
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• pp.225-232
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• 2008

An estimation has been made for inventories and characteristics of spent nuclear fuel(SNF) to be generated from existing and planned nuclear power plants based on the 3rd Basic Plan for Electric Power Demand and Supply. The characteristics under consideration in this study are dimensions, a fuel rod array, a weight, $^{235}U$ enrichment, and the discharge burnup in terms of fuel assembly. These are essentially needed for designing a pyroprocessing facility. It is appeared that the anticipated quantity by the end of 2077 is about 23,000 tU for PWR spent nuclear fuel. It is revealed that the proportion of SNF with the initial $^{235}U$ enrichment below 4.5 weight percent(wt.%) is approximately 95 % in total. For SNF with 16$\times$16 fuel rod array the proportion is expected approximately 74% in total. It appears that the average burnup of SNF will be 55 GWd/tU after the medium and/or latter part of 2010s while the average burnup is 45 GWd/tU at present. Finally, a requirement in terms of reference SNF for designing the pyroprocessing facility has been derived from the above-mentioned results. The anticipated SNF seems to be 16$\times$16 Korean Standard Fuel Assembly with a cross section of 21.4 cm$\times$21.4 cm, a length of 453 cm, a mass of 672 kg, the initial $^{235}U$ enrichment of 4.5 wt.%, and the discharge burnup of 55 GWd/tU.