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Study of Transient Control of Nonlinear Dynamically Induced Instabilities in Brillouin-Active Fiber (브릴루앙 산란에서 유발되는 비선형적인 불안정 현상에 대한 제어연구)

  • Kim, Yong-K.;Kim, Jin-Su;Park, Jae-Wan
    • Proceedings of the KIEE Conference
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    • 2004.11a
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    • pp.141-143
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    • 2004
  • In this present the transient control of SBS chaos induced instability in Brillouin-active fiber systems is described. The inherent optical feedback by the backscattered Stokes wave in optical fiber systems leads to instabilities in the form of optical chaos. At weak power, the nature of the Brillouin instability can occur at before threshold. At strong power, the temporal evolution above threshold is periodic and at higher intensity can become chaotic. Multistable periodic states, makes transition to logic 'on' or 'off'. It can make theoretically potential large memory capacity.

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Diagnostic of Cast Resin Using Active Infrared Thermal Testing Method (능동열시험법을 이용한 몰드변압기 진단)

  • Lim, Young-Bae;Jeong, Seung-Cheon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07a
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    • pp.481-484
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    • 2004
  • A form of measured temperature distribution to estimate condition of a electrical apparatus is a absolute reference for condition of the apparatus, time rate of transition, and difference between reference and currently temperature. Because passive thermography which has not injection of external thermal stimulation shows difference of temperature being on surface of a structure and temperature difference between the structure and back ground, the result could apply only to estimation or monitor for condition of terminal relaxation and overload related with temperature rising. However, a thermal flow in active thermography is differently generated by structure and condition of surface and subsurface. This paper presents the nondestructive testing using the properties and includes the results by heat injection and cooling to the apparatus. The buried discontinuity of subsurface could be detected by these techniques.

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Stereospecfic Synthesis of Cis-Alkenyl Thioethers of Mercaptolycerol (Mercaptoglycerol 중 cis-alkenyl thioethers의 입체 특이적 합성)

  • Kim, Deuk Jin;Yeo, Young Kun
    • Current Research on Agriculture and Life Sciences
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    • v.5
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    • pp.168-172
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    • 1987
  • Methods were developed to synthesize optically active mercaptoglycerol from optically active isopropylidene glycerols. 1,2-Isopropylideneglycerol was tosylated and the tosyl group displaced with thiolacetate. Base hydrolysis and oxidation gave 1,1'-dithiobis-2,3-isopropylidene-2,3-propanediol. This compound could be used as a source of mercaptoglycerol, or reacted with 1-decenyl lithium to form cis-1-S-dec-1'enyl-2,3-isopropylidene-1-mercapto-2,3-propanediol. The latter is a stereospecific synthetic route to cis-alkenyl thioethers of protected mercaptoglycerol, and it may be useful for the preparation of a thioplasmalogen substrate for plasmalogenase.

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SNMP Based Routing Process for Hand Handoff (Fast Handoff를 위한 SNMP 기반의 라우팅 프로세스)

  • 유상훈;박수현;백두권
    • Proceedings of the Korea Society for Simulation Conference
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    • 2003.11a
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    • pp.139-144
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    • 2003
  • Mobile Node has to maintain communication as they move form place to place, so it doesn't guarantee Quality of Service(QoS). Fast Handoff is important to provide multimedia and real-time applications services in mobile, and it is closely related to handoff delay. Therefore, handoff delay problem is actively studied to quarantee QoS as a main issue in mobile IP research area. Next generation Mobile IPv6 resolve this problem somewhat, triangle problem for first packet and handoff delay still remain. In this paper, we suggest SNMP Information-based routing that adds keyword management method to Information-based routing in active network in order to resolve such a problem, and then suggest QoS controlled handoff based on SNMP Information-Based routing. After modeling of suggested method and existing handoff method, simulations are carried out with NS-2 for performance evaluation. The results of simulations show the some improvement on handoff delay, and therefore on QoS improvement.

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Characterization of pH-dependent structural properties of hydrolase PncA using NMR

  • Yi, Jong-Jae;Kim, Won-Je;Rhee, Jin-Kyu;Lim, Jongsoo;Lee, Bong-Jin;Son, Woo Sung
    • Journal of the Korean Magnetic Resonance Society
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    • v.22 no.4
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    • pp.144-148
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    • 2018
  • Catalytic enzyme Pyrazinamidase (PncA) from Mycobacterium tuberculosis can hydrolyze substrate pyrazinamide (PZA) to pyrazoic acid (POA) as active form of compound. Using NMR spectroscopy, pH-dependent catalytic properties were monitored including metal binding mode during converting PZA to POA. There seems to be a conformational change through zinc binding in active site from the perturbation of peak intensities in series of 2D HSQC spectra the conformation changes through zinc binding.

Structural insights showing how arginine is able to be glycosylated by pathogenic effector proteins

  • Park, Jun Bae;Yoo, Youngki;Cho, Hyun-Soo
    • BMB Reports
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    • v.51 no.12
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    • pp.609-610
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    • 2018
  • Glycosylation is one form of protein modification and plays a key role in protein stability, function, signaling regulation and even cancer. NleB and SseK are bacterial effector proteins and possess glycosyltransferase activity, even though they have different substrate preferences. NleB/SseKs transfer the GlcNAc sugar to an arginine residue of host proteins, leading to reduced $NF-{\kappa}B-dependent$ responses. By combining X-ray crystallography, NMR, molecular dynamics, enzyme kinetic assays and in vivo experiments, we demonstrated that a conserved HEN (His-Glu-Asn) motif in the active site plays a key role in enzyme catalysis and virulence. The lid-domain regulates the opening and closing of the active site and the HLH domain determines the substrate specificity. Our findings provide evidence for the enzymatic mechanism by which arginine can be glycosylated by SseK/NleB enzymes.

Synthesis and Anti-cancer Activity of Indirubin Derivatives as the CDK Inhibitors

  • Ju, Moon-Myoung;Kim, Yong-Chul;Lee, Sang-Kook;Lee, Jong-Won
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.187.2-187.2
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    • 2003
  • The cyclin-dependent kinases (CDKs), a group of serine/threonine kinases that form active heterodimeric complexes binding to cyclins, are key regulators of the cell cycle. The role of cyclin dependent kinases(CDKs) in cell cycle regulation has stimulated an interest in them as potential targets for proliferative diseases such as cancer, psoriasis, and chemotherapeutic agent-induced alopecia. Indirubin, an active ingredient of a traditional Chinese recipe Danggui Longhui Wan, are potent CDK inhibitors competing with ATP for binding to the catalytic site of the CDKs. (omitted)

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Stochastic intelligent GA controller design for active TMD shear building

  • Chen, Z.Y.;Peng, Sheng-Hsiang;Wang, Ruei-Yuan;Meng, Yahui;Fu, Qiuli;Chen, Timothy
    • Structural Engineering and Mechanics
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    • v.81 no.1
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    • pp.51-57
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    • 2022
  • The problem of optimal stochastic GA control of the system with uncertain parameters and unsure noise covariates is studied. First, without knowing the explicit form of the dynamic system, the open-loop determinism problem with path optimization is solved. Next, Gaussian linear quadratic controllers (LQG) are designed for linear systems that depend on the nominal path. A robust genetic neural network (NN) fuzzy controller is synthesized, which consists of a Kalman filter and an optimal controller to assure the asymptotic stability of the discrete control system. A simulation is performed to prove the suitability and performance of the recommended algorithm. The results indicated that the recommended method is a feasible method to improve the performance of active tuned mass damper (ATMD) shear buildings under random earthquake disturbances.

Dynamic Modeling, Active Vibration Controller Design and Experiments For Cylindrical Shell equipped with MFC Actuators (MFC 작동기가 부착된 실린더 쉘 구조물의 동적 모델링과 능동진동제어기 설계 및 실험)

  • Kwak, Moon-K.;Jung, Moon-San
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.565-573
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    • 2007
  • This paper is concerned with the dynamic modeling, active vibration controller design and experiments for a cylindrical shell equipped with MFC actuators. The dynamic model was derived by using Rayleigh-Ritz method based on Donnel-Mushtari shell theory. The actuator and sensors for the MFC actuator equations were derived based on pin-force model. The equations of motion were then reduced to modal equations of motion by considering the modes of interest. The sensor equations were also converted to a reduced form. An aluminum shell was fabricated to demonstrate the effectiveness of modeling and control techniques. The boundary conditions at both ends of the shell were assumed to be shear diaphragm. Theoretical natural frequencies were calculated and compared to experimental result. It was observed that the theoretical result is in good agreement with experimental result for the first two modes. The multi-input and multi-output positive position feedback controller, which can cope with first two modes, was then designed based on the blockinverse theory and implemented using DSP. It was found from experiment that vibrations can be successfully suppressed.

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Kimchi Packaging Technology: An Overview

  • Jeong, Suyeon;Yoo, SeungRan
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.22 no.3
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    • pp.41-47
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    • 2016
  • This paper provides an overview of kimchi packaging technology, focusing on packaging materials, package design, and active/intelligent packaging technology for kimchi. From a packaging-material standpoint, although various materials have been used to ensure customer satisfaction and convenience, plastic is the most widely used material, in the form of bags, trays, pouches, and rigid containers. Additionally, recent efforts in the kimchi packaging industry have allowed companies to differentiate their products by using different packaging materials and technologies, while simultaneously improving product safety and quality. On the other hand, the biggest problem in kimchi packaging is excess $CO_2$ production, leading to package expansion and leakage. To alleviate this problem, the use of $CO_2$ absorbers, high $CO_2$-permeable films, and degassing valves, in addition to the use of different packaging systems, has been investigated. Active and/or intelligent packaging systems have been developed, to include active functions beyond simply inert, passive containment and protection of the kimchi product. However, most such approaches are not yet adequately effective to be useful on a commercial scale. Therefore, further studies are needed to resolve the limitations of each technology.