• 제목/요약/키워드: NAS

검색결과 286건 처리시간 0.023초

국가공역체계에서 무인항공기 통합운영에 대한 동향 (Challenges; Interoperability of UAV in the NAS)

  • 김중욱;김도현
    • 항공우주산업기술동향
    • /
    • 제8권2호
    • /
    • pp.136-144
    • /
    • 2010
  • 무인항공기의 활용도가 다양해지고 그 활동영역도 넓어지는 지금, 준비해야 하는 당면과제는 어떻게 유인항공기 공역에서 무인항공기를 안전하고 원활하게 통합 운영할 것인가 이다. 따라서 현재 무인항공 기의 연구개발 및 수요가 가장 많은 미국을 중심으로 무인항공기 통합운영에 관한 연구동향을 살펴보고 그 시사점 및 향후 공역 통합운영에 대한 방향 및 고려사항을 제시하고자 한다.

  • PDF

NAS 전지 모듈의 온도 분포 특성에 관한 연구 (A Study on the Temperature Distribution Characteristics of NAS Battery Module)

  • 허두상;이중섭;정효민;정한식
    • 한국기계가공학회지
    • /
    • 제11권4호
    • /
    • pp.1-6
    • /
    • 2012
  • This paper addresses the issue of Renewable Energy for Electricity Storage device is one of the NAS (Sodium-Sulfur) battery will be about the module. For safety reasons, not the actual battery cells using a dummy cell in the module's operating temperature setting to examine the characteristics of the insulation vacuum of the wall temperature and external temperature changes measured over time. Upper and lower boundaries of the wall vacuum insulation characteristics cotton C intervals over time, average $5^{\circ}C$, but the temperature is rising, 4C section with little temperature change did not occur. On the other hand, about $3^{\circ}C$ in section 4D, and it was confirmed that the temperature rises. Wall vacuum insulation characteristics over time to look at the experiments and measurements are described.

Robust architecture search using network adaptation

  • Rana, Amrita;Kim, Kyung Ki
    • 센서학회지
    • /
    • 제30권5호
    • /
    • pp.290-294
    • /
    • 2021
  • Experts have designed popular and successful model architectures, which, however, were not the optimal option for different scenarios. Despite the remarkable performances achieved by deep neural networks, manually designed networks for classification tasks are the backbone of object detection. One major challenge is the ImageNet pre-training of the search space representation; moreover, the searched network incurs huge computational cost. Therefore, to overcome the obstacle of the pre-training process, we introduce a network adaptation technique using a pre-trained backbone model tested on ImageNet. The adaptation method can efficiently adapt the manually designed network on ImageNet to the new object-detection task. Neural architecture search (NAS) is adopted to adapt the architecture of the network. The adaptation is conducted on the MobileNetV2 network. The proposed NAS is tested using SSDLite detector. The results demonstrate increased performance compared to existing network architecture in terms of search cost, total number of adder arithmetics (Madds), and mean Average Precision(mAP). The total computational cost of the proposed NAS is much less than that of the State Of The Art (SOTA) NAS method.

Cryopreservation of in vitro Grown Shoot Tips of Strawberry (Fragaria × ananassa Duch.) Genetic Resources by Droplet-vitrification

  • Lee, Young-Yi;Balaraju, Kotnala;Song, Jae-Young;Yi, Jung-Yoon;Lee, Sun-Yi;Lee, Jung-Ro;Yoon, Munsup;Kim, Haeng-Hoon
    • 한국자원식물학회지
    • /
    • 제32권6호
    • /
    • pp.689-697
    • /
    • 2019
  • This study describes an efficient and widely applicable droplet-vitrification following cryopreservation for shoot tips of strawberry (Fragaria × ananassa Duch.) cvs. 'Wonkyo3114' and 'Gurumi40'. The shoot tips were precultured in Murashige and Skoog (MS) liquid medium supplemented with sucrose (0.3-0.5M). Precultured explants were osmoprotected with loading solution (LS, C4) containing 20% glycerol and 20% sucrose for 40 min and exposed to dehydration solution (B5) containing 40% glycerol and 40% sucrose for 40 min at 25℃, Subsequently, the explants were transferred onto droplets containing 2.5 μL PVS3 on sterilized aluminum foils (4 cm × 0.5 cm) prior to direct immersion in liquid nitrogen (LN) for 1 h. The highest regrowth rate (%) in both the cultivars was obtained when the shoot tips were precultured with MS + 0.3M sucrose for 40 h at 25℃. The cryopreserved shoots tips exhibited 55% regrowth rate by culturing in NH4NO3-free MS medium supplemented with 3% sucrose, 1.0 g/L casein, 1.0 mg/L GA3, and 0.5 mg/L BA for 5 weeks and in MS medium supplemented with 0.5 mg/L GA3 for 8 weeks. This result shows that droplet-vitrification could be employed as a promising method for cryostorage of strawberry germplasm.

Antioxidant and Biological Activity in the Leaves of Adzuki Bean (Vigna angularis L.)

  • Lee, Kyung Jun;Lee, Jung-Ro;Shin, Myoung-Jae;Cho, Gyu-Taek;Lee, Ho-Sun;Ma, Kyung-Ho;Lee, Gi-An;Chung, Jong-Wook
    • 한국자원식물학회지
    • /
    • 제31권3호
    • /
    • pp.237-253
    • /
    • 2018
  • The adzuki bean (Vigna angularis L.) is a red-grained legume that has a number of essential nutrients and is used in traditional dishes in Asia. Adzuki bean industrial by-products are also a potential low-cost source of some unique bioactive polyphenols. Hence, here, the authors aimed to perform a comparative study of the phytochemical profiles of the leaves and seeds of the adzuki bean and compare their antioxidant, ${\alpha}$-glucosidase inhibition, and tyrosinase inhibition activity. The authors assessed antioxidant activity by DPPH, ABTS, FRAP, PR, TPC, and SOD assays, which showed wide variation, respectively. From the relative antioxidant capacity index results, 10 adzuki bean landraces were selected to compare for phytochemicals and bioactivity using leaf and seed extracts. Antioxidant, ${\alpha}$-glucosidase inhibition, and tyrosinase inhibition activity in the leaf extracts were higher than in the seed extracts, and there were more flavonols and isoflavones in the leaf extracts than in the seed extracts. This study demonstrated that adzuki bean leaf extracts could be a new natural antioxidant or antidiabetic agent and a skin whitener and can also be used in industrial applications.

Genetic Diversity and Population Structure of a Korean Rice Germplasm Based on DNA Profiles

  • Lee, Kyung Jun;Lee, Jung-Ro;Shin, Myoung-Jae;Cho, Gyu-Taek;Ma, Kyung-Ho;Lee, Gi-An;Chung, Jong-Wook
    • 한국작물학회지
    • /
    • 제63권1호
    • /
    • pp.1-7
    • /
    • 2018
  • Information on the patterns of genetic diversity and population structure is essential for the rational use and efficient management of germplasms; accurate information aids in monitoring germplasms, and can also be used to predict potential genetic gains. In this study, we assessed genetic diversity, focusing on Korean rice accessions for theand their sustainable conserved diversity. Using DNA profiling with 12 simple sequence repeat (SSR) markers, we detected a total of 333 alleles among 2,016 accessions. The number of alleles ranged from 21 to 53, with an average of 27.8. Average polymorphism information content was 0.797, with the lowest being 0.667 and the highest 0.940. CA cluster analysis and the model-based population structure revealed two main groups that could be subdivided into five subgroups. Analysis of the molecular variance study based on the SSR profile data showed 5% variance among the profiles, whereas we recorded 93% variance among individuals and 2% variance within individuals. Specifically, the utilized diversity for of the breeding program is restricted in that cultivars were located in limited clades. These results revealed that preserving the diversity of Korean landraces could be useful sources for breeding new rice cultivars, and cwould be the basis for the sustainable conservation and utilization of a Korean rice germplasm.

Effect of Soil Respiration on Light Fraction-C and N Availability in Soil Applied with Organic Matter

  • Ko, Byong-Gu;Lee, Chang-Hoon;Kim, Myung-Sook;Kim, Gun-Yeob;Park, Seong-Jin;Yun, Sun-Gang
    • 한국토양비료학회지
    • /
    • 제49권5호
    • /
    • pp.510-516
    • /
    • 2016
  • Soil respiration has been recognized as a key factor of the change of organic matter and fertility due to the carbon and nitrogen mineralization. In this study, we evaluated the effect of soil respiration on the light fraction-C and inorganic N content depending on temperature in soil applied with organic matter. Soil respiration was calculated by using total $CO_2$ flux released from soil applied with $2Mg\;ha^{-1}$ of rice straw compost and rye for 8 weeks incubation at 15, 25, $35^{\circ}C$ under incubation test. After incubation test, light fraction and inorganic N content were investigated. Rye application dramatically increased soil respiration with increasing temperature. $Q_{10}$ value of rye application was 1.69, which was higher 27% than that of rice straw compost application. Light-C and $NO_3-N$ contents were negatively correlated to soil respiration. Light-C in rye application more decreased than that in rice straw compost with temperature levels. These results indicate that temperature sensitivity of soil respiration could affect soil organic mater content and N availability in soil due to carbon availability. Also, light fraction would be useful indicator to evaluate decomposition rate of organic matter in soil under a short-term test.

작물 수분 스트레스 지수 산정을 위한 최적의 관측 간격과 시간에 대한 통계적 분석 (Statistical Analysis of Determining Optimal Monitoring Time Schedule for Crop Water Stress Index (CWSI))

  • 최용훈;김민영;오우현;조정건;윤석규;이상봉;김영진;전종길
    • 한국농공학회논문집
    • /
    • 제61권6호
    • /
    • pp.73-79
    • /
    • 2019
  • Continuous and tremendous data (canopy temperature and meteorological variables) are necessary to determine Crop Water Stress Index (CWSI). This study investigated the optimal monitoring time and interval of canopy temperature and meteorological variables (air temperature, relative humidity, solar radiation and wind speed) to determine CWSIs. The Nash-Sutcliffe model efficiency coefficient (NSE) was used to quantitatively describe the accuracy of sampling method depending upon various time intervals (t=5, 10, 15, 20, 30 and 60 minutes) and CWSIs per every minute were used as a reference. The NSE coefficient of wind speed was 0.516 at the sampling time of 60 minutes, while the ones of other meteorological variables and canopy temperature were greater than 0.8. The pattern of daily CWSIs increased from 8:00 am, reached the maximum value at 12:00 pm, then decreased after 2:00 pm. The statistical analysis showed that the data collection at 11:40 am produced the closest CWSI value to the daily average of CWSI, which indicates that just one time of measurement could be representative throughout the day. Overall, the findings of this study contributes to the economical and convenient method of quantifying CWSIs and irrigation management.

관개수준별 사과나무의 엽온 및 수분 스트레스 지수 변화 분석 (Response of Crop Water Stress Index (CWSI) and Canopy Temperature of Apple Tree to Irrigation Treatment Schemes)

  • 김민영;최용훈;조정건;윤석규;박정훈;김영진;전종길;이상봉
    • 한국농공학회논문집
    • /
    • 제61권5호
    • /
    • pp.23-31
    • /
    • 2019
  • Crop response to weather and internal water pressure changes is more sensitive to crop water stress than soil water content. Recently, its implementation to optimal irrigation scheduling has been receiving much attention. This study was conducted to determine and compare the theoretical crop water stress index (CWSI) using meterological data and canopy temperature collected from three different irrigation treatments, which were Tr-1 plot (rainfed), Tr-2 plot (50% of daily evapotranspiration (ET) irrigated) and Tr-3 plot (75% of daily evapotranspiration (ET) irrigated). The readings of canopy temperature and CWSI were significantly different among irrigation treatment schemes. The average canopy temperatures and CWSIs of Tr-1 and Tr-3 plots were $34.6^{\circ}C$ and $32.6^{\circ}C$, 0.79 and 0.64, respectively. Solar radiation had the biggest correlation with CWSI (R=0.68) which was followed by wind speed, relative humidity and air temperature. Overall, the findings of this study indicated that canopy temperatures and CWSIs could be further used for irrigation scheduling for crop growth.

개발도상국 지원을 위한 NAS기반의 K-12 학습관리 시스템 구현 방안에 대한 연구 (A Study on Implementation of NAS-based K-12 Learning Management System for Supporting Developing Countries)

  • 노인호;유갑상;김혁진
    • 디지털융복합연구
    • /
    • 제17권1호
    • /
    • pp.179-187
    • /
    • 2019
  • 아프리카를 비롯한 개발도상국은 균등한 교육기회 박탈, 열악한 교육여건, 선진국과의 정보화 격차 등으로 인적자원개발이 미미한 실정이다. 우수한 인적자원을 확보하지 못한 개발도상국은 선진국과의 세계화 경쟁에서 더욱 뒤쳐지고 있어, 개발도상국의 '인적자원개발' 문제는 시급히 해결해야 할 과제가 아닐 수 없다. 개발도상국은 교육 예산이 교육수요를 충족하고 의무 교육을 달성하기에 턱없이 낮은 수준이어서 양적으로 증가하는 교육 수요에 적절히 대응하지 못하고 있는 실정이며, 이러한 교육예산의 부족 문제는 교육 인프라 부족 문제로 연결이 된다. 본 연구에서는 NAS기반의 서버를 구성하여 교육 콘텐츠 및 학습관리 등의 기능을 구성하고, 클라이언트 영역은 태블릿, PC, 빔 프로젝터 등 다양한 미디어를 활용이 가능하도록 솔루션을 제시하여, 인트라넷 환경의 어학교육 지원을 위한 쾌적한 교육환경의 구성 및 SCORM 기반의 플랫폼을 구축을 통한 개발도상국의 최적화된 이러닝 서비스를 지원하고자 한다.