• 제목/요약/키워드: NAS

검색결과 286건 처리시간 0.023초

저속 2행정 박용 기관에서의 LO 입자 오염도에 따른 베어링 마모 특성 평가 (Evaluation of The Wear Characteristics on The White Metal Bearing in a Low Speed Two-Stroke Marine Diesel Engine)

  • 안용희;김대영;김은철;박득진
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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    • pp.21-22
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    • 2005
  • A study on the wear characteristics of the white metal(Sn-base alloy) bearing as a function of particle contamination level was conducted in order to establish control criteria of the lubricant in the 2-stroke marine diesel engine. Particle contamination level of the lubricants ranged from NAS 10 to 12 for the experiments. Bar-on-plate type wear test was performed using reciprocating wear tester. Based on this study it was found that there was no noticeable difference in weight loss of the white metal for NAS10 and NAS11(particle contamination level). Surface roughness of the white metal bearing after the wear test of 8hrs for the highly contaminated lubricant(NAS12 level) was up to $6{\mu}m$ in Rmax whilst that of the less contaminated lubricants(NAS10 & 11) was less than $1.5{\mu}m$ in Rmax.

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Group Master Cache를 활용한 SAN과 NAS의 통합 방안 (Application of Group Master Cache for the Integrated Environment of SAN and NAS)

  • 이원복;박진원
    • 한국시뮬레이션학회논문지
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    • 제16권2호
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    • pp.9-15
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    • 2007
  • 인터넷이 급성장하고 멀티미디어와 같은 대용량 데이터의 사용이 증가함에 따라 스토리지 시스템은 스토리지가 서버에 직접 연결되어 있던 DAS에서. 스토리지를 별개의 전용 네트워크로 연결한 SAN, 그리고 스토리지가 IP 네트워크에 연결되어 파일 서비스 기능만 전담하는 NAS로 발전하게 되었다. 그러나 SAN과 NAS를 독립적으로 사용하면 다양한 기업의 요구를 충족시키지 못한다. 그래서 등장한 것이 SAN과 NAS의 통합이다. 본 연구에서는 SAN과 NAS의 통합 방법의 하나인 MCI(Metadata server and Cluster Interation)를 바탕으로, MCI의 구현과 확장에 따른 비용 증가 문제를 해결하기 위해 GMC(Group Master Cahce)라는 개념을 제안하여 보다 효율적인 데이터 공유 방안을 제시한다. CMC의 기본 개념을 소개하고 기존의 MCI와 새로 제시하는 GMC를 컴퓨터 시뮬레이션을 통해 성능 측면에서 비교 분석하였다.

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공정관리 과학화를 위한 지하철공사 NAS운영체계 데이터베이스 모델링 구축 (Database Model of Subway Construction NAS Operating System for Scheduling Management Science)

  • Choi, Jaejin;Cho, Byounghoo;Park, Hongtae
    • 한국재난정보학회 논문집
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    • 제13권3호
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    • pp.322-331
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    • 2017
  • 본 연구는 한국건설기술연구원(KICT)에서 제시한 토목공사용 정보분류체계(Information Classification System)를 기반으로 지하철공사의 정보분류체계를 제시하였다. 그리고 이 기준을 근거로 NAS(Network Analysis System) 운영체계인 공사정보분류체계 - 공정도표 - 작업별 투입 자원을 연동하는 데이터 모델링을 구축하여 통합 모형을 제시하였다. 따라서 본 연구에서 제시한 데이터 모델링의 통합모형은 다른 토목시설물공사에서도 동일한 절차와 방법으로 적용할 수 있어, NAS를 기반으로 한 공정관리 과학화를 유도할 수 있을 것으로 확신한다.

Training-Free Hardware-Aware Neural Architecture Search with Reinforcement Learning

  • Tran, Linh Tam;Bae, Sung-Ho
    • 방송공학회논문지
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    • 제26권7호
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    • pp.855-861
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    • 2021
  • Neural Architecture Search (NAS) is cutting-edge technology in the machine learning community. NAS Without Training (NASWOT) recently has been proposed to tackle the high demand of computational resources in NAS by leveraging some indicators to predict the performance of architectures before training. The advantage of these indicators is that they do not require any training. Thus, NASWOT reduces the searching time and computational cost significantly. However, NASWOT only considers high-performing networks which does not guarantee a fast inference speed on hardware devices. In this paper, we propose a multi objectives reward function, which considers the network's latency and the predicted performance, and incorporate it into the Reinforcement Learning approach to search for the best networks with low latency. Unlike other methods, which use FLOPs to measure the latency that does not reflect the actual latency, we obtain the network's latency from the hardware NAS bench. We conduct extensive experiments on NAS-Bench-201 using CIFAR-10, CIFAR-100, and ImageNet-16-120 datasets, and show that the proposed method is capable of generating the best network under latency constrained without training subnetworks.

Preconditioning for Cryopreservation of in vitro Grown Bulblets of Lily using Droplet-Vitrification

  • Jae-young Song;Jinjoo Bae;Young-yi Lee;Jung-yoon Yi;Jung-ro Lee;Mun-sup Yoon
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2021년도 춘계학술대회
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    • pp.35-35
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    • 2021
  • This study was conducted to improve and supplement the system of cryopreservation for adventitious bulbs induced by tissue cultured bulb-scales of lily (Lilium spp.) cvs. 'MilkyWay'. The explants, bulblets and bulb-scale-bulblets, were treated to low temperature (4℃) for 7 days prior to the pre-culture. The adventitious bulbs were pre-cultured in Murashige and Skoog (MS) liquid medium supplemented with sucrose (0.3 and 0.7M). The pre-cultured adventitious bulbs were treated to loading solution (LS1 or LS2, C4 or C6) containing 35% of PVS3 (LS1, C4) or 40% of PVS3 (LS2, C6) for 40 min and exposed to dehydration solution (PVS3, B1) containing 50% glycerol and 50% sucrose for 60 min at 25℃. The adventitious bulbs were moved onto droplets containing 3 ㎕ PVS3 on sterilized aluminum foils, and then soaked into liquid nitrogen (LN) for 60 min. The result of highest regrowth rate as 65.7% was obtained in cold treatment (4℃), osmoprotected with LS1 solution, and cultured in PCM3 medium by using bulb-scale-bulblet for cryopreservation. This result shows that droplet-vitrification could be used as a promising method for long-term storage of lily genetic resource.

Response of Germination Rate to Variable Drying Conditions and Moisture Contents for Storage of Dehisced Korean Ginseng Seeds

  • Lee, Young-yi;Rajametov, Sherzod;Kim, Young-chang;Yi, Jung-yoon;Lee, Gi-an;Gwak, Jae-gyun;Son, Eun-ho;Park, Hong-jae
    • 한국자원식물학회지
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    • 제29권6호
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    • pp.670-678
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    • 2016
  • We compared the germination rate of dehisced ginseng (Panax ginseng) seeds that were dried under two different conditions, slowly at $15^{\circ}C$ [relative humidity (RH) 10-12%] and rapidly under a laminar airflow cabinet at $25^{\circ}C$ (RH 22-25%). The measurements showed that drying rate and seed moisture content (SMC) play important roles in storage ability and vigor. The seeds that were dried rapidly at $25^{\circ}C$ showed high GR compared with the seeds that were dried at $15^{\circ}C$ after 6 and 12 months of storage at $-80^{\circ}C$ irrespective of MC. Seeds dried slowly at $15^{\circ}C$ with MC higher than 7.0% showed high GR maintenance after storage at $-18^{\circ}C$ and at $4^{\circ}C$ in comparison with rapidly dried seeds. However, the GR of the slowly desiccated seeds decreased as mean SMC was reduced to less than 5.0%, whereas the rapidly dried seeds were distinguished by significantly high GR irrespective of the storage conditions. The ginseng seeds desiccated under different conditions showed differences in storage performance. Seeds with 7-9% MC that were dried slowly at $15^{\circ}C$ for 5-7 days showed high GR after $4^{\circ}C$ and $-18^{\circ}C$ storage; however, longer periods of desiccation decreased the germination level remarkably compared with that of rapidly dried seeds.

Variation in Agronomic Traits and Fatty Acid Compositions of the Seed Oil in Germplasm Collection of Brassica spp.

  • Ko, Ho-Cheol;Sung, Jung-Sook;Hur, On-Sook;Baek, Hyung-Jin;Lee, Myung-Chul;Luitel, Binod Prasad;Ryu, Kyoung-Yul;Rhee, Ju-Hee
    • 한국자원식물학회지
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    • 제30권6호
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    • pp.590-600
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    • 2017
  • A total of 447 accessions consisting of seven Brassica spp.; Brassica carinata (34), B. juncea (199), B. rapa subsp. dichotoma (18), B. rapa. subsp. oleifera (14), B. rapa subsp. rapa (36), B. rapa subsp. trilocularis (56) and B. alba subsp. alba (90) were studied for their morphological characters and fatty acid compositions. There was a wide variation for morphological traits, oil content and fatty acid composition among Brassica species. Seed number/silique and yield/plant were varied from 4.2 (B. alba) to 25.1 (B. rapa subsp. trilocularis) and from 170.7 g (B. rapa subsp. oleifera) to 351.9 g (B. juncea L. Czern.), respectively. Among Brassica species, B. rapa subsp. trilocularis exhibited the highest oil (29.2%), stearic (20.4%) and erucic acid (45.3%) content. B. carinata had the highest content of palmitic (5.2%), oleic (21.2%) and linolenic acid (11.1%). B. rapa subsp. dichotoma and B. rapa subsp. oleifera exhibited the highest content of linoleic (8.1%) and behenic (26.9%) acid, respectively. B. rapa subsp. trilocularis exhibited the highest (45.3%) erucic acid content and significant positive relationship was observed between oleic acid and linoleic acid. This variation of agronomic and fatty acid compositions in Brassica species can be utilized to develop new varieties.

Morphological Characterization of Fagopyrum esculentum Germplasm for Rutin and Quercetin Contents

  • Rauf, Muhammad;Choi, Yu Mi;Lee, Sukyeung;Hyun, Do Yoon;Lee, Myung-Chul;Oh, Sejong;Yoon, Hyemyeong
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2019년도 춘계학술대회
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    • pp.52-52
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    • 2019
  • Buckwheat is well-known crop for containing a high contents of flavonoids that are effective in vascular disease. The current study was performed to estimate the influence of morphological characterization of Fagopyrum esculentum (ES) germplasm for seed's two major flavonoids contents: rutin and quercetin. We found that the red stem color, pale green leaf color, arrowhead leaf shape, white flower color, pale brown seed coat color, and egg-shaped seed were significantly associated with 77%, 56.7%, 83.7%, 98.7%, 70.8% and 74.5% germplasm, respectively. Overall, the rutin contents of ES germplasm ranged from 0.30 to 47.86 mg/100g dry weight (DW) and the quercetin contents ranged from 0 to 1.22 mg/100g DW. The rutin contents of germplasm possessing red stem color, pale green leaf color, arrowhead leaves, white flower color, pale brown seed coat color and egg-shaped seed ranged from 7.22 to 47.86 mg/100g DW. However, the quercetin contents of germplasm with red stem color and pale brown seed coat color ranged from 0 to 1.15 mg/100g DW, with pale green leaves ranged from 0 to 0.96 mg/100g, with arrowhead leaves and white flower ranged from 0 to 1.22 mg/100g and with egg-shaped seed ranged from 0.32 to 1.22 mg/100g DW. In PCA analysis, the first three principal components (PCs) showed Eigen value more than 1 and accounted for 51.70% of variation. For both higher contents of rutin and quercetin, the morphological evaluation in ES shows a tendency of red stem color, arrowhead leaves, pale green leaf color, white flower color, pale brown seed coat color and egg-shaped seed. From this information, we can assume the rutin and quercetin contents by the morphological characteristics of the germplasm. And It could be useful in improving the rutin and quercetin contents and selecting proper resources for cultivation in existing buckwheat cultivars.

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Efficient Cryopreservation of in vitro Grown Shoot Tips of Pear (Pyrus spp.) by Droplet-vitrification

  • Jae-Young Song;Jinjoo Bae;Ji-Won, Han;Ho Cheol Ko;Ho-sun Lee;Sung-Hee Nam;Jung-RoLee;Byeong Hyeon Yun;Keumsun Kim;Kyungho Won;Il Sheob Shin
    • 한국자원식물학회지
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    • 제36권6호
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    • pp.571-579
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    • 2023
  • In this study, cryopreservation by droplet-vitrification was applied to pear (Pyrus spp.) germplasm. We focused on the development and assessment of various strategies for the selection of suitable tissue, osmoprotection, and dehydration. We also evaluated post-thaw recovery of cryopreserved explants by droplet-vitrification. Preferentially, we tested the effects of preculture and loading treatments to determine which tissues were more suitable, either the apical shoot tips or the axillary buds. Apical shoot tips showed the better regrowth rate than in vitro axillary buds. The most effective techniques for cryopreservation were as follows. Shoots from in vitro seedlings which had been cultured for about 5-6 weeks were cold-hardened at 4℃ for one week, excised shoot tips were precultured on liquid MS medium including 0.3 M sucrose for 31 hours and 0.7 M sucrose for 17 hours, osmoprotected in loading solution (LS) for 40 min, and then cryoprotected in dehydration solution (PVS3) for 90 min. In addition, we found that regrowth rates of explants on regrowth medium after exposure to liquid nitrogen (LN) were higher than those on MS medium. Results indicated that the highest regrowth percentage was 95.6% for 'Bartlett' cultivar and 68.9% for 'BaeYun No.3' cultivar. Consequently, apical shoot tips of two pear cultivars, 'Bartlett' (P. communis) and 'BaeYun No.3' (P. pyrifolia), were successfully cryopreserved by droplet-vitrification. Results of this study show that the enhanced droplet-vitrification method described in the present study could be used as an effective means for long-term storage of pear genetic resources.