• Title/Summary/Keyword: Big-O

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Ab Initio Study of the Structure and Binding Energy of HOOCl-H2O Cluster (HOOCl-H2O Cluster의 구조와 결합에너지에 대한 ab initio 연구)

  • Kim, Young-Mi;Sung, Eun-Mo
    • Journal of the Korean Chemical Society
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    • v.52 no.3
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    • pp.322-327
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    • 2008
  • The geometrical structure, binding energy and vibrational frequencies of HOOCl-H2O cluster were investigated with MP2/6-311G(d,p) and MP2/6-311G(2d,2p) methods. The most stable conformer is skew HOOCl-H2O cluster and the binding energy was 46~48kJ/mol. The trans HOOCl-H2O cluster is less stable than skew form, but the binding energy is big enough to stablize the complex. The vibrational frequencies of skew and trans HOOCl-H2O cluster were calculated and compared with the spectrum of HOOCl.

N-Tosyl Calix[4]arene Azacrown Ether, $C_{45}H_{49}NO_6S$

  • Kim, Jong-Seung;Kim, Moon-Jib;Choo, Geum-Hong;Lee, Jin-Ho;Suh, Il-Hwan
    • Korean Journal of Crystallography
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    • v.10 no.1
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    • pp.66-70
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    • 1999
  • The calix[4]arene molecule adopting the 1,3-alternate conformation forms a square cavity, and two pair phenyl rings lying above and below a least-square plane defined by the four bridging methylene groups in the calix[4]arene are widened upwards and downwards, respectively, from central axis, which leads to O1-O4=4.064 and O2-O3=3.864 . Two propyloxy groups are stabilized with all trans conformations, but the rather short azacrown ether chain with two oxygen atoms includes cis/trans conformations with O1-C35=2.906 . Therefore the cavity does not seem to be big enough to form a host-guest complex.

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CO Gas Sensing Characteristic of ZnO Thin Film/Nanowire Based on p-type 4H-SiC Substrate at 300℃ (P형 4H-SiC 기판에 형성된 ZnO 박막/나노선 가스 센서의 300℃에서 CO 가스 감지 특성)

  • Kim, Ik-Ju;Oh, Byung-Hoon;Lee, Jung-Ho;Koo, Sang-Mo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.2
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    • pp.91-95
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    • 2012
  • ZnO thin films were deposited on p-type 4H-SiC substrate by pulsed laser deposition. ZnO nanowires were formed on p-type 4H-SiC substrate by furnace. Ti/Au electrodes were deposited on ZnO thin film/SiC and ZnO nanowire/SiC structures, respectively. Structural and crystallographical properties of the fabricated ZnO thin film/SiC and ZnO nanowire/SiC structures were investigated by field emission scanning electron microscope and X-ray diffraction. In this work, resistance and sensitivity of ZnO thin film/SiC gas sensor and ZnO nanowire/SiC gas sensor were measured at $300^{\circ}C$ with various CO gas concentrations (0%, 90%, 70%, and 50%). Resistance of gas sensor decreases at CO gas atmosphere. Sensitivity of ZnO nanowire/SiC gas sensor is twice as big as sensitivity of ZnO thin film/SiC gas sensor.

warton 관애의 타석증 1예

  • Lee, Gi-Wan
    • The Journal of the Korean dental association
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    • v.5 no.1
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    • pp.60-62
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    • 1964
  • The Author have had a case of Salivary-stone in the posterior of Warton's duct in the right Side . 1. The patient was 24 years-old R.O.K.a Soldexr. 2. The salivary stone was 1.6cm by 2.11 cm in big size. 3. There was a History of pain at meal-time, and swelling of mandible of Right region.

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The Electrical and Microstructural Properties of ZnO:N Thin Films Grown in The Mixture of $N_2$ and $O_2$ by RF Magnetron Sputtering

  • Jin, Hu-Jie;Lee, Eun-Cheal;So, Soon-Jin;Park, Choon-Bae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.144-145
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    • 2006
  • ZnO is a promising material to make high efficiency violet or blue light emitting diodes (LEDs) for its large binding energy (60meV) and big bandgap. But the high quality p-type conduction of ZnO is a dilemma to achieve LEDs with it. In present study, we presented a reliable method to prepare ZnO thin films on (100)silicon substrates by RF magnetron sputtering in the mixture ambient of $N_2$ and $O_2$, accompanying with low pressure annealing in the sputtering chamber in $O_2$ at $600^{\circ}C$ and $800^{\circ}C$ respectively. X-ray diffraction and Hail effect with Van der Paul method were performed to test ZnO films. Seeback effect was also carried out to identify carrier types in ZnO films and showed the N-doped ZnO film annealed at $800^{\circ}C$ had achieved p-type conduction.

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A Classification of Medical and Advertising Blogs Using Machine Learning (머신러닝을 이용한 의료 및 광고 블로그 분류)

  • Lee, Gi-Sung;Lee, Jong-Chan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.11
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    • pp.730-737
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    • 2018
  • With the increasing number of health consumers aiming for a happy quality of life, the O2O medical marketing market is activated by choosing reliable health care facilities and receiving high quality medical services based on the medical information distributed on web's blog. Because unstructured text data used on the Internet, mobile, and social networks directly or indirectly reflects authors' interests, preferences, and expectations in addition to their expertise, it is difficult to guarantee credibility of medical information. In this study, we propose a blog reading system that provides users with a higher quality medical information service by classifying medical information blogs (medical blog, ad blog) using bigdata and MLP processing. We collect and analyze many domestic medical information blogs on the Internet based on the proposed big data and machine learning technology, and develop a personalized health information recommendation system for each disease. It is expected that the user will be able to maintain his / her health condition by continuously checking his / her health problems and taking the most appropriate measures.

Design of a Large-scale Task Dispatching & Processing System based on Hadoop (하둡 기반 대규모 작업 배치 및 처리 기술 설계)

  • Kim, Jik-Soo;Cao, Nguyen;Kim, Seoyoung;Hwang, Soonwook
    • Journal of KIISE
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    • v.43 no.6
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    • pp.613-620
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    • 2016
  • This paper presents a MOHA(Many-Task Computing on Hadoop) framework which aims to effectively apply the Many-Task Computing(MTC) technologies originally developed for high-performance processing of many tasks, to the existing Big Data processing platform Hadoop. We present basic concepts, motivation, preliminary results of PoC based on distributed message queue, and future research directions of MOHA. MTC applications may have relatively low I/O requirements per task. However, a very large number of tasks should be efficiently processed with potentially heavy inter-communications based on files. Therefore, MTC applications can show another pattern of data-intensive workloads compared to existing Hadoop applications, typically based on relatively large data block sizes. Through an effective convergence of MTC and Big Data technologies, we can introduce a new MOHA framework which can support the large-scale scientific applications along with the Hadoop ecosystem, which is evolving into a multi-application platform.

Development of Brake System with ABS Function for Aircraft

  • Jeon, Jeong-Woo;Woo, Gui-Aee;Lee, Ki-Chang;Kim, Yong-Joo
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.423-427
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    • 2003
  • In this paper, it is to development of brake system with ABS function for aircraft. The test of brake system is required before applying on aircraft. The real-time dynamic simulator with 5-D.O.F. aircraft dynamic model is developed for braking performance test of ABS (Anti-skid Brake System) control h/w with anti-skid brake functions. The dynamic simulator is real-time interface system that is composed of dynamic simulation parts, master control parts, digital and analog in/out interface parts, and user interface parts. The 5-D.O.F. aircraft dynamic model is composed of a big contour and a little contour by simulation s/w. The big contour represents the interactions of forces in airframe, nose and main landing gear, and engines on the center of gravity. The little contour represents interactions of wheel, braking units, hydraulic units and a control unit. ABS control h/w unit with ABS control algorithm is also developed and is tested with simulator under the some conditions of gripping coefficient. We have known that ABS control h/w unit on wet or snowy runway as well as dry runway very well protects wheel skid.

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A Parallel HDFS and MapReduce Functions for Emotion Analysis (감성분석을 위한 병렬적 HDFS와 맵리듀스 함수)

  • Back, BongHyun;Ryoo, Yun-Kyoo
    • Journal of the Korea society of information convergence
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    • v.7 no.2
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    • pp.49-57
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    • 2014
  • Recently, opinion mining is introduced to extract useful information from SNS data and to evaluate the true intention of users. Opinion mining are required several efficient techniques to collect and analyze a large amount of SNS data and extract meaningful data from them. Therefore in this paper, we propose a parallel HDFS(Hadoop Distributed File System) and emotion functions based on Mapreduce to extract some emotional information of users from various unstructured big data on social networks. The experiment results have verified that the proposed system and functions perform faster than O(n) for data gathering time and loading time, and maintain stable load balancing for memory and CPU resources.

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O&M Evaluating for Sewage Treatment Plants in China as a Developing Country (개발도상국 중국의 하수처리장 운영.관리능 평가)

  • Kim, Kwon-Youn;Moon, Yong-Taik;Kim, Hong-Suck;Kim, Ji-Yeon
    • Journal of environmental and Sanitary engineering
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    • v.21 no.3 s.61
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    • pp.27-36
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    • 2006
  • For the last 20 years, China has transformed itself from a rural economy into an industrial giant, averaging over 8 % annual growth of GDP. Unfortunately, this rapid growth has taken a significant toll on its natural resource base as well, particularly water resources. These problems have been exacerbated by a low level of sewage treatment technology and by the operating and maintenance (O&M). In case of urban areas, most big cities in China have a well functioning sewage system comprised of sewers and sewage treatment plants (STPs). Nevertheless, the existing STPs are still not capable of properly treating the sewage, both quantitatively and qualitatively. The rural areas in China cover a large land, with two-third of the nation's population. The low educational and poor economic states make it hard to process self-protection and management. In the surveyed area in Henan, there was no STPs put into use as of 2004, and the sewer lines are not well organized. The big issue for the currently planned STPs is the collection system not included in the plans.