• 제목/요약/키워드: A321

검색결과 2,581건 처리시간 0.027초

Cryopreservation of Sporothalli of the Genus Porphyra (Bangiales, Rhodophyta) from Korea

  • Jo, Young-Hyun;Kang, Sung-Pil;Seo, Tae-Ho;Choi, Sung-Je;Kho, Kang-Hee;Kuwano, Kazuyoshi;Saga, Naotsune;Kim, Min-Yong;Shin, Jong-Ahm
    • ALGAE
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    • 제18권4호
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    • pp.321-331
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    • 2003
  • Cryopreservation of sporothalli of the red alga Porphyra (P. seriata, P. yezoensis, P. tenera, P. pseudolinearis and P. dentata) was performed by the two-step cooling method in liquid nitrogen. The algal samples were suspended in various cryoprotective solutions, and slowly cooled to -40$^{\circ}C$ in 4 hours using a programmed freezer. After the first slow cooling the suspensions with cryoprotectants were immediately immersed in liquid nitrogen. The suspension from the programmed freezer was thawed quickly by agitation of the vial in a water bath at 40°C. When ice in the suspension of cryogenic vial was mostly melted, the vial was transferred to an ice bath for complete melting of the residual ice. The cryoprotectants in the vial were washed off by gradual dilution with seawater. The viability of the cell was assessed with neutral red staining. The viability of Porphyra samples ranged 54.6-70.9% when the mixed suspension of 10% dimethylsulfoxide and 0.5 M sorbitol in 50% seawater used as a cryoprotectant.

A Modified Multiple Depth First Search Algorithm for Grid Mapping Using Mini-Robots Khepera

  • El-Ghoul, Sally;Hussein, Ashraf S.;Wahab, M. S. Abdel;Witkowski, U.;Ruckert, U.
    • Journal of Computing Science and Engineering
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    • 제2권4호
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    • pp.321-338
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    • 2008
  • This paper presents a Modified Multiple Depth First Search algorithm for the exploration of the indoor environments occupied with obstacles in random distribution. The proposed algorithm was designed and implemented to employ one or a team of Khepera II mini robots for the exploration process. In case of multi-robots, the BlueCore2 External Bluetooth module was used to establish wireless networks with one master robot and one up to three slaves. Messages are sent and received via the module's Universal Asynchronous Receiver/Transmitter (UART) interface. Real exploration experiments were performed using locally developed teleworkbench with various autonomy features. In addition, computer simulation tool was also developed to simulate the exploration experiments with one master robot and one up to ten slaves. Computer simulations were in good agreement with the real experiments for the considered cases of one to one up to three networks. Results of the MMDFS for single robot exhibited 46% reduction in the needed number of steps for exploring environments with obstacles in comparison with other algorithms, namely the Ants algorithm and the original MDFS algorithm. This reduction reaches 71% whenever exploring open areas. Finally, results performed using multi-robots exhibited more reduction in the needed number of exploration steps.

Cosmetic Lateral Canthoplasty: Lateral Canthoplasty to Lengthen the Lateral Canthal Angle and Correct the Outer Tail of the Eye

  • Chae, Soo Wook;Yun, Byung Min
    • Archives of Plastic Surgery
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    • 제43권4호
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    • pp.321-327
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    • 2016
  • There are many women who want larger and brighter eyes that will give a favorable impression. Surgical methods that make the eye larger and brighter include double eyelidplasty, epicanthoplasty, as well as lateral canthoplasty. Double eyelidplasty produces changes in the vertical dimension of the eyes, whereas epicanthoplasty and lateral canthoplasty create changes in the horizontal dimension of the eyes. Epicanthoplasty, a surgical procedure which enlarges the eye horizontally, is performed at the inner corner of the eye, whereas lateral canthoplasty enlarges the outer edge of the eye. In particular, if the slant of the palpebral fissure is raised and the horizontal dimension of the palpebral fissure is short, adjusting the slant of the palpebral fissure through lateral canthoplasty can achieve an enlargement of eye width and smoother features. Depending on the patient's condition, even better results can be achieved if this procedure is performed in conjunction with other procedures, such as double eyelid-plasty, epicanthoplasty, eye roll formation surgery, fat graft, and facial bone contouring surgery. In this paper, the authors will introduce in detail their surgical method for a cosmetic lateral canthoplasty that lengthens the lateral canthal angle and corrects the outer tail of the eyes, in order to ease the unfavorable impression.

다중 표준 시스템을 위한 이득 곡선 제어기를 가진 가변이득 증폭기 설계 (Design of Variable Gain Amplifier with a Gain Slope Controller in Multi-standard System)

  • 최문호;이원영;김영석
    • 한국전기전자재료학회논문지
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    • 제21권4호
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    • pp.321-328
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    • 2008
  • In this paper, variable gain amplifier(VGA) with a gain slope controller has been proposed and verified by circuit simulations and measurements. The proposed VGA has a gain control, gain slope switch and variable gain range. The input source coupled pair with diode connected load is used for VGA gain stage. The gain slope controller with switch can control VGA gain slope. The proposed VGA is fabricated in $0.18{\mu}m$ CMOS process for multi -standard wireless receiver. The proposed two stage VGA consumes min. 2.0 mW to max. 2.6 mW in gain control range and gives input IP3 of -3.77 dBm and NF of 28.7 dB at 1.8 V power supply under -25 dBm, 1 MHz input. The proposed VGA has 37 dB(-16 dB $\sim$ 21 dB) variable gain range, and 8 dB gain range control per 0.3 V control voltage, and can provide variable gain, positive and negative gain slope control, and gain range control. This VGA characteristics provide design flexibility in multi-standard wireless receiver.

In vitro Nasal Cell Culture Systems for Drug Transport Studies

  • Cho, Hyun-Jong;Termsarasab, Ubonvan;Kim, Jung-Sun;Kim, Dae-Duk
    • Journal of Pharmaceutical Investigation
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    • 제40권6호
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    • pp.321-332
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    • 2010
  • Growing interest in the nasal route as a drug delivery system calls for a reliable in vitro model which is crucial for efficiently evaluating drug transport through the nasal cells. Various in vitro cell culture systems has thus been developed to displace the ex vivo excised nasal tissue and in vivo animal models. Due to species difference, results from animal studies are not sufficient for estimating the drug absorption kinetics in humans. However, the difficulty in obtaining reliable human tissue source limits the use of primary culture of human nasal epithelial cells. This shortage of human nasal tissue has therefore prompted studies on the "passage" culture of nasal epithelial cells. A serially passaged primary human nasal epithelial cell monolayer system developed by the air-liquid interface (ALI) culture is known to promote the differentiation of cilia and mucin gene and maintain high TEER values. Recent studies on the in vitro nasal cell culture systems for drug transport studies are reviewed in this article.

자기부상시스템의 자기력 모델링 시스템 개발 (Development of Magnetic Force Modeling Equipment for Magnetic Levitation Systems)

  • 양지혁;김석윤;이영삼;권오규
    • 제어로봇시스템학회논문지
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    • 제17권4호
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    • pp.321-327
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    • 2011
  • This paper proposes an equipment and an algorithm for modeling the magnetic force of electromagnets in magnetic levitation systems. We assume that the magnetic force model is represented in terms of a 2D lookup table. The 2D lookup table is constructed by applying noncausal filtering and interpolation to data measured by the proposed modeling equipment. The proposed modeling equipment is designed such that it can measure the magnetic force exerted on the levitation object while it changes the voltage applied to the electromagnet and position of the levitation object. The algorithm of making a 2D lookup table has two stages. The data measured by the proposed modeling equipment is smoothed by a noncausal filter and then the 2D lookup table is obtained by interpolating filtered data. The proposed modeling method has advantages of time-saving, model consistency, and chance of automation for mass production. We show the validity of proposed method through control experiments.

Modern Software Defined Radar (SDR) Technology and Its Trends

  • Kwag, Young-Kil;Jung, Jung-Soo;Woo, In-Sang;Park, Myeong-Seok
    • Journal of electromagnetic engineering and science
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    • 제14권4호
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    • pp.321-328
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    • 2014
  • Software defined radar (SDR) is a multi-purpose radar system where most of the hardware processing is performed by software. This paper introduces a concept and technology trends of software defined radar, and addresses the advantages and limitations of the current SDR radar systems. For the advanced SDR concept, the KAU SDR Model (KSM) is presented for the multimode and multiband radar system operating in S-, X-, and K-bands. This SDR consists of a replaceable multiband antenna and RF hardware, common digital processor module with multimode, and open software platform based on MATLAB and LabVIEW. The new concept of the SDR radar can be useful in various applications of the education, traffic monitoring and safety, security, and surveillance depending on the various radar environments.

웹 2.0 기반의 유비쿼터스 헬스케어 모니터링 시스템 (Ubiquitous Healthcare Monitoring System based on Web 2.0)

  • 정필성;오영환
    • 한국통신학회논문지
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    • 제37권4C호
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    • pp.321-328
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    • 2012
  • 스마트폰과 같은 모바일 장치는 휴대가 간편한 소형 컴퓨팅 장치로서 기존 컴퓨터에서 수행하던 작업을 수행할 수 있으며 맞춤형 개인화 서비스가 가능하여 널리 활용되고 있다. 모바일 장치에서 동작하는 모바일 애플리케이션은 모바일 플랫폼의 특성에 따라서 호환성이 떨어지기는 특징을 가지기 때문에 해당 플랫폼을 지원하기 위해서는 플랫폼에 맞게 다시 개발해야 하는 제약사항을 가진다. 본 논문에서는 이를 해결하기 위해서 표준 웹 개발 언어인 HLTML5와 자바스크립트 라이브러리인 jQuery를 이용하여 다양한 모바일 플랫폼에서 호환성을 가지는 유비쿼터스 헬스케어 모니터링 시스템을 구현하였다. 구현된 시스템은 모바일 플랫폼뿐만 아니라 데스크톱 컴퓨터에서도 호환성을 가지기 때문에 다양한 환경에서 활용이 가능하다.

Prevalence and Diversity of MBL Gene-Containing Integrons in Metallo-β-Lactamase (MBL)-Producing Pseudomonas spp. Isolates Disseminated in a Korean Hospital

  • Yum, Jong Hwa
    • 대한의생명과학회지
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    • 제25권4호
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    • pp.321-330
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    • 2019
  • Carbapenem is recently considered as the last resort of the therapeutics for gram negative bacterial infection. Increasing of organisms producing metallo-β-lactamase (MBL), we have difficulty in choosing the antimicrobial agents. Among 345 clinical isolates of Pseudomonas spp., 61 isolates (17.7%) were positive for the modified imipenem or meropenem-Hodge test and 55 isolates (15.9%) were positive for the imipenem-EDTA + SMA double disk synergy test (DDS). PCR and sequencing of blaVIM-2-allele and blaIMP-1-allele showed that 17 isolates of Pseudomonas aeruginosa, 9 isolates of Pseudomonas taiwnensis and 2 Pseudomonas plecoglossicida had blaVIM-2, and 22 isolates of P. aeruginosa and one Pseudomonas otitidis had blaIMP-6. These MBL genes were all in class 1 integron. The size of class 1 integron with blaVIM-2 ranged from 3.5 kb to 5.5 kb in clinical isolates of Pseudomonas spp. including P. aeruginosa. blaVIM-2 was most often located first in the class 1 integron, sometimes in the second or third position, and these integrons often had aacA4 or aadA1. Strict infection control measures are needed to more effectively prevent further spread of these MBL-producing Pseudomonas spp. In addition, MBL-producing Pseudomonas spp. is expected to continue to spread in various countries and regions.

Peat stabilization using cement, polypropylene and steel fibres

  • Kalantari, Behzad;Prasad, Arun;Huat, Bujang B.K.
    • Geomechanics and Engineering
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    • 제2권4호
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    • pp.321-335
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    • 2010
  • This article describes a laboratory research on stabilizing tropical peat using ordinary Portland cement (OPC) as a binding agent, and polypropylene and steel fibres as chemically inert additives. California bearing ratio (CBR) and unconfined compressive strength (UCS) tests were carried out to evaluate the increase in the strength of the stabilized samples compacted at their optimum moisture contents and air cured for up to 90 days. The results show that the UCS values of stabilized peat samples increased by as high as 748.8% by using OPC (5%), polypropylene fibres (0.15%), and steel fibres (2%). The CBR values of the samples stabilized with OPC (5%), polypropylene fibres (0.15%), and steel fibres (4%) showed an increase of as high as 122.7%. The stabilized samples showed a shrinkage in volume upon air curing and this shrinkage was measured by an index called, volume shrinkage index (VSI). The highest VSI recorded was 36.19% for peat without any additives; and the minimum was 0% for the sample containing 30% OPC, 0.15% polypropylene fibres and 2% steel fibres. The technique of stabilizing peat with OPC, polypropylene and fibres, coupled with air curing, appears to be cost-effective compared with other frequently used techniques.