• Title/Summary/Keyword: Exciting current

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Current status of research on radionuclides used in nuclear mediccine (중성자선 실험 및 발암연구의 현황과 미래)

  • Kim, Hui-Seon
    • Radioisotope journal
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    • v.21 no.3
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    • pp.46-60
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    • 2006
  • In recent years the progress of nuclear medicine advanced dramatically in imaging and targeted radionuclide therapy is able to open op exciting perspectives as standard diagnostic and therapeutic modalities, complementing conventional modalities. Positron emission tomography/computed tomography (PET/CT) technology with FDG has been developed clinically in less than 10 years as a routine standard in oncological imaging, including a number of other fluorinated radiopharmaceuticals being evaluated for their ability to complement FDG. However, the limitation of FDG-PET such as non-specific uptake and its short half-life is not compatible with the time necessary for optimal tumour targeting. Therefore, a development of innovative positron-emitting radionuclides with half-lives longer than 10 h is needed. For therapeutic applications, the injection of higher activities is required to reach efficient adsorbed doses in radioresistant solid tumours, while limiting the irradiation of vital organs. In this application, the longer half-life of radiolsotopes are more fit well for radionuclide therapy. To achieve this, researches have to be carried in a largor spectrum of radionuclides for diagnosis and therapy. In the context of rapidly growing nuclear medicine and strong demanding innovative radionuclides, a high-energy (100 MeV), high-intensity (-mA) accelerator with proton (PEFF at KAFRI). will be operating in 2011. The priorities of PEFP will include supporting the nuclear medicine research community by providing those radionuclides with current limited availability by means of a high-energy, high-intensity accelerator.

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Experiments and Dynamics Simulation of a Moving Flat Core Type LOA (평판철심 가동형 리니어 액츄에이터의 동특성 시뮬레이션 및 실험)

  • Jang, S.M.;Cho, H.W.;Lee, S.H.;Kweon, C.
    • Proceedings of the KIEE Conference
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    • 2002.07b
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    • pp.663-665
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    • 2002
  • Moving flat core type LOA consists of iron flat core as a mover and electric magnet as a stator and operated by electromagnetic force between mover and stator. First, this paper describes the voltage equation of coil and the mechanical equation of motion. Secondly, the dynamic simulation algorithm is proposed, and system control constant-inductance, resistance-were carried by exciting coil. Finally, we turned out the driving system and the dynamic characteristics of current, voltage and displacement is confirmed by experiment.

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Sirtuins in Cancer: a Balancing Act between Genome Stability and Metabolism

  • Jeong, Seung Min;Haigis, Marcia C.
    • Molecules and Cells
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    • v.38 no.9
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    • pp.750-758
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    • 2015
  • Genomic instability and altered metabolism are key features of most cancers. Recent studies suggest that metabolic reprogramming is part of a systematic response to cellular DNA damage. Thus, defining the molecules that fine-tune metabolism in response to DNA damage will enhance our understanding of molecular mechanisms of tumorigenesis and have profound implications for the development of strategies for cancer therapy. Sirtuins have been established as critical regulators in cellular homeostasis and physiology. Here, we review the emerging data revealing a pivotal function of sirtuins in genome maintenance and cell metabolism, and highlight current advances about the phenotypic consequences of defects in these critical regulators in tumorigenesis. While many questions should be addressed about the regulation and context-dependent functions of sirtuins, it appears clear that sirtuins may provide a promising, exciting new avenue for cancer therapy.

Interactive Technology Education at Pusan National University

  • Park, Sang-Joo;Yoon, Joong-Sun
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1195-1200
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    • 2004
  • We introduce an introductory engineering education course for engineering majors and non-engineering majors. This course does not require any previous knowledge and experience on engineering. It requires strong curiosities and imaginations on current and future society we live in, where technology is inseparable ingredient. Course encourages attendees to explore fundamental issues of engineering: what is proper technology and what are proper ways of exercising engineering, issues dealt in soft engineering. Since course topics cover many aspects of technology, traditional learning methods fail to be successful and efficient. Various efficient learning methods have been proposed and implemented. We utilize various interactive tangible media, which include simulated thought experiments and physical media experiences. About 20 episodes in short film format are produced based on scenario written according to related issues selected. Physical media like interactive robots are introduced for attendees' stimulated experiences. We summarize our exciting experiments on interactive teaching experiences at Pusan National University which include on/off-line interactions, assignments, projects, and evaluations.

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Design of An Automated Contract Match-making System for VE Implementation (가상기업 구현을 위한 계약중개 자동화 시스템의 설계)

  • 정동길
    • The Journal of Society for e-Business Studies
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    • v.6 no.1
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    • pp.1-16
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    • 2001
  • This paper describes a preliminary investigation of contracts with a view towards automating the process of contract match-making. A novel approach based on exploiting Standard Form Contracts(SFC) is described. The approach is shown to be implementable with current technology. A second approach based on Standard Contract Clauses(SCC) which overcomes some of the limitations of Standard Form Contracts, is briefly outlined. The flexibility offered by this approach however, is accompanied by a considerable increase in the complexity of contract match-making. Both Standard Form Contracts and Standard Contract Clauses based match-making point towards an exciting area of future research.

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Dynamic characteristics analysis of the magnetic actuator brake system (MASS) for emergency a car (비상 제동기능을 지닌 전자력 브레이크 시스템(MABS)에 대한 제안 및 동작특성해석)

  • Kang, Jong-Ho;Kim, Tae-Young;Choi, Sang-Min;Jung, Hyun-Kyo
    • Proceedings of the KIEE Conference
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    • 2006.04b
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    • pp.68-70
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    • 2006
  • This paper formulates the principle of the magnetic actuator break system (MASS) for emergency situation driving a car. When the exciting break system of a car is broken, MASS will be able to stop the car by the electric system. MASS controls the rotating wheel to slow down gradually while holding and laying the wheel down several ten times per second. We present the magnetic field and dynamic behavior analyses for the magnetic actuator break system using finite element method (FEM) associated with parameter, for calculating the displacement of the moving parts and the supplying current.

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Increment of HTS Magnet's Central Magnetic Field Made of Pancake Windings by Using Separate Sources (여러개의 전원을 이용한 팬케이크 권선으로 구성된 고온초전도 마그넷의 중심자장 증가)

  • Lee, Kwang-Youn;Cha, Guee-Soo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.9
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    • pp.1577-1583
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    • 2007
  • The development of a magnet for very high magnetic field is usually envisioned with the use of an HTS insert coil. Pancake windings have been commonly used for the insert coil. All pancake windings have been connected in series and excited by a single power source. In that case, it is inevitable to operate some of the pancake windings well below their critical current densities. To increase the central magnetic field of the magnet, this paper proposed a new excitation method of the pancake windings by exciting the pancakes windings independently using multiple power sources. Results of the calculation show proposed method increases the central magnetic field of the magnet which consisted of 8 pancake windings by 17% comparing with excitation by using a single power source.

Vibration Characteristics of a Wire-Bonding Piezoelectric Actuator (와이어 본딩용 압전 액츄에이터의 진동 특성)

  • Kim, Young-Woo;Kim, Kyoung-Up;Lee, Seung-Yop
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.578-582
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    • 2007
  • In this paper, vibration modes and frequencies of a ring-type stacked piezoelectric actuator for a wire bonding transducer system are analyzed using FEM simulations. We implement experiments using a commercial product model of the actuator PZT module which consists of 6 layer ring-type PZT and 7 electrodes, combined bolts, nut and tinut. There are two main results: One is that FEM analysis should consider the effect the harmonic voltage input in order to meet the experimental results. The other is that the current wire bonder using exciting frequency of 136 kHz should be modified in order to improve the actuator and bonding performance because the actuator module has the main longitudinal mode of 145 kHz.

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Preparation, Properties and Application of Polyamide/Carbon Nanotube Nanocomposites

  • Chen, Peng;Kim, Hun-Sik;Jin, Hyoung-Joon
    • Macromolecular Research
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    • v.17 no.4
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    • pp.207-217
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    • 2009
  • The discovery of carbon nanotubes(CNTs) has opened up exciting opportunities for the development of novel materials with desirable properties. The superior mechanical properties and excellent electrical conductivity make CNTs a good filler material for composite reinforcement. However, the dispersal of CNTs in a polymer solution or melt is difficult due to their tendency to agglomerate. Many attempts have been made to fully utilize CNTs for the reinforcement of polymeric media. Therefore, different types of polymer/CNTs nanocomposites have been synthesized and investigated. This paper reviews the current progress in the preparation, properties and application of polyamide/CNTs(nylon/CNTs) nanocomposites. The effectiveness of different processing methods has increased the dispersive properties of CNTs and the amelioration of their poor interfacial bonding. Moreover, the mechanical properties are significantly enhanced even with a small amount of CNTs. This paper also discusses how reinforcement with CNTs improves the electrical thermal and optical properties of nylon/CNTs nanocomposites.

Applications of Digital Holography in Biomedical Microscopy

  • Kim, Myung-K.
    • Journal of the Optical Society of Korea
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    • v.14 no.2
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    • pp.77-89
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    • 2010
  • Digital holography (DH) is a potentially disruptive new technology for many areas of imaging science, especially in microscopy and metrology. DH offers a number of significant advantages such as the ability to acquire holograms rapidly, availability of complete amplitude and phase information of the optical field, and versatility of the interferometric and image processing techniques. This article provides a review of the digital holography, with an emphasis on its applications in biomedical microscopy. The quantitative phase microscopy by DH is described including some of the special techniques such as optical phase unwrapping and holography of total internal reflection. Tomographic imaging by digital interference holography (DIH) and related methods is described, as well as its applications in ophthalmic imaging and in biometry. Holographic manipulation and monitoring of cells and cellular components is another exciting new area of research. We discuss some of the current issues, trends, and potentials.