• Spatial Information Research
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• 제23권2호
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• pp.1-9
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• 2015

그래픽 처리 장치(GPU)는 내부에 대량의 산술 논리 연산 장치(ALU)를 보유하고 있다. 대량의 ALU는 병렬 처리를 위해 이용될 수 있으므로, GPU는 효율적인 데이터 처리를 제공한다. 공간 데이터를 지도상에 표현하기 위하여 지리학적 좌표가 필요하다. 좌표들은 측지경도와 측지위도의 형태로 저장된다. 데카르트 좌표계로 구성된 지도를 표현하기 위하여 측지경도와 측지위도는 국제 횡단 메르카토르 좌표계(UTM)로 전환돼야 한다. 좌표계 변환 과정과 변환된 좌표를 화면상에 표현하기 위한 렌더링 과정은 복잡한 부동 소수점 계산이 필요하다. 본 논문에서는 성능 향상을 위해 GPU를 활용한 좌표변환 과정과 렌더링 과정을 병렬적으로 처리하는 기법을 제안한다. 대용량 공간 데이터는 파일로 디스크 내에 저장된다. 대용량 공간 데이터를 효율적으로 처리하기 위하여 공간 데이터 파일들을 하나의 대용량 파일로 병합하고 Memory Mapped File 기법을 활용하여 파일에 접근하는 기법을 제안한다. 본 논문에서는 TIGER/Line 데이터를 활용하여 747,302,971개의 점으로 구성된 공간 데이터의 좌표 변환 및 렌더링 처리 과정을 GPU를 활용하여 병렬로 수행하는 연구를 진행한다. CPU를 이용하여 좌표변환 과정 결과와 렌더링 처리 과정 결과를 비교하여 속도 향상 정도에 대한 결과를 제시한다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.169-173
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• 2008

Stirling engine is a promising heat engine with a high efficiency, muti-fuel capability, low emission, quiet operation, very low maintenance and long life. As one of the promising applications, solar power system based on the Stirling dish, providing net solar-to-electric conversion efficiencies reaching 30%, can operate as stand-alone units in remote locations or can be linked together in groups to provide utility-scale power. This paper introduced a new Scroll-type Stirling engine, being developed for solar power, superior to conventional Stirling engines. The Scroll-type Stirling engine is characterized as traits of continuous and wholly separated compression and expansion; one-way flow system; direct cooling and heating the fluid in the working spaces through the extensive inner surfaces of scroll wraps. All theses traits contribute to achieving thermodynamic cycle closer to the ideal Stirling cycle (exactly speaking, Ericsson cycle).

• 생명과학회지
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• 제20권2호
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• pp.260-268
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• 2010

가물치(Channa argus) 조직의 젖산탈수소효소 동위효소(EC 1.1.1.27, lactate dehydrogenase, LDH)를 정제하고 생화학적, 면역학적 및 역학적 방법으로 특성을 연구하였다. LDH 활성은 골격근이 380.4 units로 가장 높고 심장 13.4, 눈 3.5, 뇌 조직 5.4 units이었으며, 심장의 CS 활성은 20.7 unit로 가장 높고, LDH/CS는 골격근 172.9, 심장 0.6, 눈 0.32, 뇌 0.47이고, 단백질 양은 골격근 14.7 mg/g이며, 특이활성(units/mg)은 골격근 25.88, 심장 0.79, 눈 0.31, 뇌 1.38 units/mg이었으므로 골격근은 혐기적이고, 심장은 호기적이었다. LDH $A_4$, $B_4$, eye-specific $C_4$에 대한 항혈청을 사용한 Western blot, 면역침강반응 및 native-polyacrylamide gel electrophoresis에 의해 $A_4$, $A_3B$, $A_2B_2$, $AB_3$ 및 $B_4$가 모든 조직에서 확인되었고, 눈 조직에서 $C_4$와 $AC_3$, $A_2C_2$, $AC_3$, 뇌 조직에서 $A_3C$도 확인되었다. LDH $A_4$, $A_3B$, $A_2B_2$, $AB_3$, $B_4$, eye-specific $C_4$ 동위효소는 affinity chromatography와 Preparative PAGE Cell에 의해 정제되었다. LDH $A_4$ 동위효소는 $NAD^+$ 유입 후 정제되었고, eye-specific $C_4$는 $A_4$에 이어 용출되기 시작하였으며 $B_4$는 buffer 유입 후 용출되었다. 정제한 결과 $A_4$는 $B_4$ 및 eye-specific $C_4$와 분자구조의 일부가 유사하였지만 $B_4$와 $C_4$는 서로 다른 것으로 나타났으므로, 하부단위체 A는 보존적이고, 하부단위체 B는 A보다 더 빠르게 진화된 것으로 보인다. 피루브산 10 mM에서 $A_4$ 동위효소 39.98%, $A_2B_2$ 21.28%, $B_4$ 19.67% 및 eye-specific $C_4$ 16.87%의 활성이 남아있었고, 피루브산에 대한 $Km^{PYR}$은 $A_4$ 0.17 mM, $B_4$ 0.27 mM, eye-specific $C_4$ 0.133 mM였다. $A_4$, $B_4$, eye-specific $C_4$, $A_2B_2$, $A_3B$ 및 $AB_3$의 최적 pH는 각각 pH 6.50, pH 8.5, pH 5.5, pH 6.0-6.5, 5.0 및 pH 7.5였고, 동질사량체 $A_4$와 이질사량체 동위효소들은 넓은 pH 영역에서 안정하였다. 특히 골격근은 LDH 활성이 크므로 활동성이 크며, 눈조직에서 피루브산 친화력이 강한 eye-specific $C_4$에 의해 피루브산 대사가 빠르게 일어나고, 이어서 $A_4$에 의해 젖산이 산화되어지는 것으로 사료되므로, 종의 생태환경 및 먹이 획득 양식에 따라 LDH-C 발현, 기질에 대한 친화도 및 대사 시간이 다른 것으로 사료된다.

• 실내환경 및 냄새 학회지
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• 제17권4호
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• pp.355-361
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• 2018

Mold grows more easily when humidity is higher in indoor spaces, and as such is found more often on wetted areas in housing such as walls, toilets, kitchens, and poorly managed spaces. However, there have been few studies that have specifically assessed the level of mold in the indoor spaces of water-damaged housing in the Republic of Korea. We investigated the levels of airborne mold according to the characteristics of water damage types and explored the correlation between the distribution of mold genera and the characteristics of households. Samplings were performed from January 2016 to June 2018 in 97 housing units with water leakage or condensation, or a history of flooding, and in 61 general housing units in the metropolitan and Busan area, respectively. Airborne mold was collected on MEA (Malt extract agar) at flow rate of 100 L/min for 1 min. After collection, the samples were incubated at $25^{\circ}C$ for 120 hours. The cultured samples were counted and corrected using a positive hole conversion table. The samples were then analyzed by single colony culture, DNA extraction, gene amplification, and sequencing. By type of housing, concentrations of airborne mold were highest in flooded housing, followed by water-leaked or highly condensed housings, and then general housing. In more than 50% of water-damaged housing, the level of airborne mold exceeded the guideline of Korea's Ministry of Environment ($500CFU/m^3$). Of particular concern was the fact that the I/O ratio of water-damaged housing was greater than 1, which could indicate that mold damage may occur indoors. The distribution patterns of the fungal species were as follows: Penicillium spp., Cladosporium spp. (14%), Aspergillus spp. (13%) and Alternaria spp. (3%), but significant differences of their levels in indoor spaces were not found. Our findings indicate that high levels of mold damage were found in housing with water damage, and Aspergillus flavus and Penicillium brevicompactum were more dominant in housing with high water activity. Comprehensive management of flooded or water-damaged housing is necessary to reduce fungal exposure.

• 한국가금학회지
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• 제6권2호
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• pp.91-102
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• 1979

The basic problem of the broiler industry is that of fluctuating prices, mainly thanks to unstable supply of and inelastic demand for products as usually indicated as a peculiarity of agricultural commodities. This particularly brings the producer to a great economic risk, because he has to sell products under the condition of pure competition, whereas others from whom he has to buy deal under the condition of oligopoly or even monopoly. Therefore, producers economic position is generally placed in the worst comparing others dealing with, which results in unbalanced economic status of elements involved in broiler operation and further obstruction of industry development as a whole. A certain type of business coordination to overcome such a problem should be measured in order to improve the efficiency of entire operation and thus assure the balanced industry development. The concept of the economic integration developed in modern business system had been adapted to U.S. poultry industry which became common later around the world as a means of stabilizing producers price and whole industry as well. There are two main typos of integration; horizontal and vertical The former refers to the general grouping of similar business units, eg. a hatchery tying with other hatchery, while the latter refers to the knitting together of two or more stages of economic activities, eg. tying together among units of hatching, fled milling, production, processing and marketing. By having the industry integrated, risk and uncertainty involved in various stages of operation could be diversified. The typo of integrating contract between producers and integrators include the share of profits, flat fee payment, feed conversion payment and salary basis. In the U.S., extensive changes in production, processing, and marketing during the last few decades have changed the thicken broiler industry from one of small, widely scattered farms to one that is largo, concentrated and efficient. More than 99 percent of all broilers produced are grown under contract and by integrated firms which vary in size of operation and complexity. About 84 percent of all production is concentrated in 10 States. Some of the other factors ;hat contributed to these choses arc costs, energy use, prices, processing, marketing and demand. No integrated broiler production system has yet been applied in Korea's poultry industry, thus all stages all broiler operation run independently seeking for its own profit. Consequently, producers price fluctuate very widely around the year even more than 50 percent in a few months. This also leads to disadvantages of material supplies, processors and distributors and enforce the industry unstable. The current economic environment in Korea seems that the time for broiler integration comes and as an ideal integrator, feed millers, food processors and producers group may be considered.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제22권4호
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• pp.261-280
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• 2019

본 연구는 부모와 자녀 간 수학학습 지도 사례에 대한 질적 연구로, 초등학교 5학년 자녀에게 교구 활동 중심수업을 적용하면서 자녀의 넓이 개념의 습득과정과 어려움을 느끼는 문제 유형, 그리고 부모와 자녀의 학습 상황에서 부모가 겪는 장점과 어려움을 확인하고자 하였다. 이를 위해 총 12차시 지도안을 구성하여 2019년 1학기에 수업을 진행하면서 관찰과 면담을 통해 자료 수집을 하였다. 아이는 수업을 통해 넓이 개념을 정확하게 인식하게 되었는데, 보존 중 재구성에 대한 인식이 생겼으며, 분할, 단위 반복, 배열 구성에 대한 개념도 더 명확하게 인식하였다. 넓이 수업 과정 중 넓이 단위 간 변환, 높이가 외부에 표시되는 도형의 높이 표시, 넓이를 제시한 후 같은 넓이를 가진 도형 그리기 유형의 문제에서 어려움을 보였다. 부모와 자녀의 학습 상황에서 연구자인 부모는 자녀에 대한 맞춤 수업이 가능하고 기회와 비용의 제약을 받지 않는다는 장점을 가졌으나 자녀에 대한 감정 제어와 자녀의 수준 파악, 수업 시간 배분, 개입 수준을 정하는데 어려움이 있었다. 본 연구결과를 통해 부모와 자녀 간 활동 중심의 수학 학습 지도와 관련하여 앞으로 더 많은 연구가 이루어지길 기대한다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권4호
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• pp.564-573
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• 2019

Objective: Evaluate the effects of i) dehulling of lupine seed on chemical composition and apparent metabolizable energy (AME) and ii) soybean meal substitution by dehulled lupine seed in broiler diets with enzymes on productive performance, size of digestive organs and welfare-related variables. Methods: Experiment 1, chemical composition and AME were determined in whole and dehulled lupine seed. Experiment 2, two hundred eighty-eight one-day-old male Ross 308 broilers were used. The experimental diets were maize-soybean meal (MS), MS with enzymes (MSE) and maize-dehulled lupine seed with enzymes (MLE). Diets were assigned to the experimental units under a completely randomized design (eight replicates per diet). The body weight (BW) gain, feed intake, feed conversion, digestive organ weights, gait score, latency to lie down and valgus/varus angulation were evaluated. Results: The dehulling process increased protein (25.0% to 31.1%), AME (5.9 to 8.8 MJ/kg) and amino acid contents. The BW gain of broilers fed the MLE diet was similar (p>0.05) to that of those fed the MS diet, but lower than that of those fed the MSE diet. Feed intake of broilers fed the MLE diet was higher (p<0.05) than that of those fed the MS diet and similar (p>0.05) to those fed the MSE diet. Feed conversion of broilers fed the MLE diet was 8.0% and 8.7% higher (p<0.05) than that of those fed the MS and MSE diets, respectively. Broilers fed the MLE diet had the highest (p<0.05) relative proventriculus and gizzard weights, but had poor welfare-related variables. Conclusion: It is possible to substitute soybean meal by dehulled lupine seed with enzymes in broiler diets, obtaining similar BW gains in broilers fed the MLE and MS diets; however, a higher feed intake is required. Additionally, the MLE diet reduced welfare-related variables.

• 한국가금학회지
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• 제33권1호
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• pp.41-47
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• 2006

본 연구는 산란계의 생산성과 계란의 품질에 미치는 지렁이 분말(EWM)의 첨가 효과를 구명하기 위해서 실시되었다. 총 360수의 55주령의 산란계를 공시하여서 EWM 0(대조구), 0.3, 0.6%를 첨가한 사료로 5주 동안의 사양 시험을 실시하였다. 계란은 매일 수집하여 난중을 측정하였고 산란율 및 사료 요구율은 시험기간 동안 매주 단위로 조사하였다. 뿐만 아니라 시험 마지막 주에는 계란의 품질도 측정하였다. 산란율과 일일 평균 산란량은 EWM 0.3 및 0.6% 급여 모두 대조구에 비해서 증가하는 경향이 인정되었지만, 0.3 % 와 0.6%처리구간에는 차이가 인정되지 않았다. 한편 사료 섭취량과 사료 요구율은 처리구간에 차이는 인정되지 않았다. 난각 두께, 강도, 색 및 난황색은 EWM 0.3 및 0.6% 처리구 모두 대조구와 비교해서 개선되는 경향이 인정되었다. 산란 1일째, haugh unit는 처리구간에 차이는 인정되지 않았지만, 보관기간에 따른 haugh unit의 변화는 EWM 급여구에서 커졌다. 지렁이분말(EWM)중의 As, Cd, Cr, Hg 및 Pb는 각각 4.41, 1.23, 1.18, 0.00 및 3.39ppm검출되었지만, 계란중에는 검출되지 않았다. 결론적으로 55주령의 산란계에 0.3%지렁이 분말(EWM)의 첨가는 산란계의 생산성 및 계란의 품질을 개선시킬 가능성이 인정된다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.245.2-245.2
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• 2013

Solution processed organic photovoltaic devices have relatively less attention compared to polymer photovoltaic devices even though they have high possibility to be developed because they have both advantages of polymer and organic, such as solution processable, no synthetic batch dependence of photovoltaic performance, high purity and high charge carrier mobility as well as relatively high efficiency (~7%). In addition, solution processed organic photovoltaic devices have an advantage of easiness to study the relationship between the molecular structure and photovoltaic performance due to its simple structure. In this work, five isoindigo based low band gap donor-acceptor-donor (D-A-D) small molecules with different electron donating strength were synthesized for investigating the relationship between the molecular structure and photovoltaic performance, especially, investigating the effects of different electron donating effect of donor group in isoindigo backbone to photovoltaic device performance. The variation of electron donating strength of donor group strongly affected the optical, thermal, electrochemical and photovoltaic device performances of isoindigo organic materials. The highest power conversion efficiency of ~3.2% was realized in bulk heterojuction photovoltaic device consisted of the ID3T as donor and PC70BM as acceptor. This work demonstrates the great potential of isoindigo moieties as electron deficient units as well as guideline for synthesis of donor-acceptor-donor (D-A-D) small molecules for realizing highly efficient solution processed organic photovoltaic devices.

• 한국수소및신에너지학회논문집
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• 제14권1호
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• pp.35-45
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• 2003

Polymer electrolyte fuel cells(PEFC) have been considered to be a suitable candidate for residential, portable and mobile applications, due to their high efficiency and power density, even at low operating temperature. KIER developed a 5kW class PEFC system for residential application and operated the system for over 1,000 hours. To develop a 5kW PEFC system, performance of a cell was improved through successive tests of single cell of small and large area. Fabrication of three 2,5 kW class stacks, design and fabrication of natural gas reformer, design of auxiliary equipments such as DC/DC converter, DC/AC inverter and humidifying units were carried out along with integration of components, operation and evaluation of total system. During the development period from 1999 to 2001, MEA(membrane electrode assembly) fabrication technologies, design and fabrication technologies for separators, stacking technologies and so on were developed, thereby providing basis for developing stacks of higher efficiency and power density in the future. Experience of development of natural gas reformer opened possibilities to use various kinds of fuels. Main results obtained from the development of a 5kW class PEFC system for residential application are summarized.