• Title/Summary/Keyword: Common Ground System

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Low Power 4-Gb/s Receiver for GND-referenced Differential Signaling (접지기반 차동신호 전송을 위한 저전력 4-Gb/s 수신단 설계)

  • Lee, Mira;Kim, Seok;Jeong, Youngkyun;Bae, Jun-Han;Kwon, Kee-Won;Chun, Jung-Hoon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.49 no.9
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    • pp.244-250
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    • 2012
  • This paper describes a 4-Gb/s receiver circuit for a low-swing ground-referenced differential signaling system. The receiver employs a common-gate level-shifter and a continuous linear equalizer which compensates inter-symbol-interference (ISI) and improves voltage and timing margins. A bias circuit maintains the bias current of the level-shifter when the common level of the input signal changes. The receiver is implemented with a low-power 65-nm CMOS technology. When 4-Gb/s 400mVp-p signals are transmitted to the receiver through the channel with the attenuation of -19.7dB, the timing margin based on bit error rate (BER) of $10^{-11}$ is 0.48UI and the power consumption is as low as 0.30mW/Gb/s.

The Emergence of Green Chemistry: Triple-Helix for Environmental Science in United States (녹색화학의 출현: 미국 환경과학의 삼중나선)

  • Jeon, June
    • Journal of Science and Technology Studies
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    • v.13 no.1
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    • pp.111-143
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    • 2013
  • Green chemistry is a new scientific field which focuses on the design, manufacture, and use of chemical processes that could prevent pollution and at the same time improve yield efficiency. The few who have written on the emergence of green chemistry have not shed light on the political and economic motivations of green chemistry. As a new study of the emergence of green chemistry, this paper focuses on the relationship among the triple helix of academia, industry, and government which has been critical in the emergence of green chemistry. This paper argues that academia, industry and government created a common ground during the emergence of green chemistry under the common goal of sustainable development since its creation in 1991. Green chemists produced the knowledge to improve the synthetic efficiency to prevent pollution, and the chemical industry used green chemistry research to increase the economic profitability of production system. This specific form of alliance was supported and maintained amid a changing national environmental policy toward pollution prevention and a self-regulatory framework.

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A Case of Microscopic Polyangiitis with Diffuse Alveolar Hemorrhage (폐출혈을 동반한 현미경적 다발혈관염 1예)

  • Lee, Sang-Jin;Lee, Jae-Woung;Kim, Hye-Jin;Shin, Kyeong-Cheol;Chung, Jin-Hong;Lee, Kwan-Ho;Park, Hye-Jung
    • Journal of Yeungnam Medical Science
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    • v.21 no.1
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    • pp.101-107
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    • 2004
  • Diffuse alveolar hemorrhage is a rare but serious and frequently life-threatening complication of a variety of conditions. The first goal in the management of patients with diffuse alveolar hemorrhage is to achieve or preserve stability of the respiratory status. Subsequently, the differential diagnosis is aimed at the identification of a remediable cause of the alveolar hemorrhage. The most common causes of diffuse alveolar hemorrhage with glomerulonephritis are microscopic polyangiitis and Wegener's granulomatosis, followed by Goodpasture syndrome and systemic lupus erythematosus. Microscopic polyangiitis (MPA) is a distinct systemic small vessle vasculitis affecting small sized vessels with few or no immune deposits and with no granulomatosus inflammation. The disease may involve multiple organs such as kidney, lung, skin, joint, muscle, gastrointestinal tract, eye, and nervous system. MPA is strongly associated with antineutrophil cytoplasmic autoantibody (ANCA) that is a useful serological diagnostic marker for the most common form of necrotizing vasculitis. Our report concerns a case of microscopic polyangiitis with diffuse alveolar hemorrhage in a 54-year-old man. He was admitted to our hospital due to dyspnea upon exertion and recurrent hemoptysis. Laboratory findings showed hematuria, proteinuria and deterioration of renal function. In the chest CT scan, diffuse ground glass appearance was seen in both lower lungs. A lung biopsy revealed small vessel vasculitis with intraalveolar hemorrhage and showed a positive reaction to against perinuclear ANCA. The patient was treated with prednisolone and cyclophosphamide. Chest infiltration decreased and hemoptysis and hypoxia improved. He is still being followed up in our hospital with a low dose of prednisolone.

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Development of a Duplexer Module for Remote Wireless Communication System of Guided Weapon System with Temperature-Insensitive Electrical Performances (온도변화에 둔감한 전기적 특성을 가지는 유도무기체계 원격무선통신시스템용 듀플렉서 모듈 개발)

  • Choi, Byung-Chang
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.27 no.8
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    • pp.709-716
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    • 2016
  • In this paper, A duplexer module with temperature-insensitive electrical characteristics was proposed for remote wireless communication system. Duplexer modules are required to have performances of low insertion loss, high isolation between transmitted band and received band, harmonic suppression as well as high power durability in the system for transmitting guided information to missile flying a free space on the ground. The proposed duplexer module are consist of transmission bandpass filter and receiving bandpass filter which are connected to common antenna port, planar coupler for output power monitoring and low pass filter for harmonic attenuation of power amplifier and coaxial cavity resonator. The material and dimensions of the resonator are determined for minimum frequency shift by temperature variation using 3D EM simulation. The measured results of the prototype showed a good agreement with the simulation results, and it should be well applied not only for guided weapon systems but also for any other communication systems such as remote radio head.

System Identification Analysis on Soil-Structure Interaction Using Field Data (현장자료를 사용한 지반-구조물 상호작용에 대한 경험적 연구)

  • Kim Seung Hyun
    • Journal of the Korean Geotechnical Society
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    • v.21 no.2
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    • pp.37-46
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    • 2005
  • In the field of earthquake engineering, recent improvements in many areas, such as seismological source modeling, analysis of travel path effects, and characterization of local site effects on strong shaking, have led to significant advances in both code-based and more advanced procedures for evaluating earthquake ground motions. A missing link, however, is empirically verified design procedures fur assessing the effects of soil-structure interaction (SSI). Available Soil-Structure Interaction (SSI) analysis techniques range from simple substructure-type procedures to relatively sophisticated finite element procedures. The most common substructure approach for foundation-soil interaction is to use a frequency-dependent and complex-valued impedance function. This study uniquely evaluates impedance functions for two well-instrumented sites w significant inertial SSI effects using a system Identification technique. The system identification analysis results are then compared to predictions from a simple theoretical model to gain insight into the inertial interaction effect in the subject sites.

The primary cilium as a multiple cellular signaling scaffold in development and disease

  • Ko, Hyuk-Wan
    • BMB Reports
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    • v.45 no.8
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    • pp.427-432
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    • 2012
  • Primary cilia, single hair-like appendage on the surface of the most mammalian cells, were once considered to be vestigial cellular organelles for a past century because of their tiny structure and unknown function. Although they lack ancestral motility function of cilia or flagella, they share common ground with multiciliated motile cilia and flagella on internal structure such as microtubule based nine outer doublets nucleated from the base of mother centrioles called basal body. Making cilia, ciliogenesis, in cells depends on the cell cycle stage due to reuse of centrioles for cell division forming mitotic spindle pole (M phase) and assembling cilia from basal body (starting G1 phase and maintaining most of interphase). Ciliary assembly required two conflicting processes such as assembly and disassembly and balance between these two processes determines the length of cilia. Both process required highly conserved transport system to supply needed substance to grow tip of cilia and bring ciliary turnover product back to the base of cilia using motor protein, kinesin and dynein, and transport protein complex, IFT particles. Disruption of ciliary structure or function causes multiple human disorder called ciliopathies affecting disease of diverse ciliated tissues ranging from eye, kidney, respiratory tract and brain. Recent explosion of research on the primary cilia and their involvement on animal development and disease attracts scientific interest on how extensively the function of cilia related to specific cell physiology and signaling pathway. In this review, I introduce general features of primary cilia and recent progress in understanding of the ciliary length control and signaling pathways transduced through primary cilia in vertebrates.

Effect of the Rock Characteristics Condition on the Behavior of Tunnel by Numerical Analysis (수치해석에 의한 암반특성의 변화가 터널에 미치는 영향)

  • Kwon, Soon-Sub;Lee, Jong-Sun;Kim, Kyoung-Ho;Lee, Jun-Woo
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.375-378
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    • 2007
  • The selection of the support system is an important design parameter in design and construction of the tunnel using the new Australian tunnel method. It is a common practice to select the support based on the rock mass grade, in which the rock mass is classified into five rock groups. The method is applicable if the characteristics of the rock mass are uniform in the direction of tunnel excavation. However, such case is seldom encountered in practice and not applicable when the properties vary along the longitudinal direction. This study performs comprehensive three dimensional finite difference analyses to investigate the ground deformation pattern for cases in which the rock mass properties change in the direction of the tunnel axis. The numerically calculated displacements at the tunnel crown show that the displacement is highly dependent on the stiffness contrast of the rock masses. The results strongly indicate the need to select the support type $0.5\sim1.0D$ before the rock mass boundary. The paper proposes a new guideline for selecting the support type based the results of the analyses.

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Effect of Vertical Change of the Rock Mass Characteristics on Rock Mass Classification by Numerical Analysis (암반특성의 수직변화가 암반분류에 미치는 영향에 관한 수치해석적 연구)

  • Kwon, Soon-Sub;Lee, Jong-Sun;Woo, Sung-Won;Lee, Jun-Woo
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.476-479
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    • 2007
  • The selection of the support system is an important design parameter in design and construction of the tunnel using the new Australian tunnel method. It is a common practice to select the support based on the rock mass grade, in which the rock mass is classified into five rock groups. The method is applicable if the characteristics of the rock mass are uniform in the vertical direction. However, such case is seldom encountered in practice and not applicable when the properties vary along the vertical direction. This study performs comprehensive three dimensional finite difference analyses to investigate the ground deformation pattern for cases in which the rock mass properties change in the vertical direction of the tunnel axis. The numerically calculated displacements at the tunnel crown show that the displacement is highly dependent on the stiffness contrast of the rock masses. The results strongly indicate the need to select the support type $0.5{\sim}1.0D$(vertical direction) on the rock mass boundary. The paper proposes a new guideline for selecting the support type based the results of the analyses.

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Fragility curves for the typical multi-span simply supported bridges in northern Pakistan

  • Waseem, Muhammad;Spacone, Enrico
    • Structural Engineering and Mechanics
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    • v.64 no.2
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    • pp.213-223
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    • 2017
  • Bridges are lifeline and integral components of transportation system that are susceptible to seismic actions, their vulnerability assessment is essential for seismic risk assessment and mitigation. The vulnerability assessment of bridges common in Pakistan is very important as it is seismically very active region and the available code for the seismic design of bridges is obsolete. This research presents seismic vulnerability assessment of three real case simply supported multi-span reinforced concrete bridges commonly found in northern Pakistan, having one, two and three bents with circular piers. The vulnerability assessment is carried through the non-linear dynamic time history analyses for the derivation of fragility curves. Finite element based numerical models of the bridges were developed in MIDAS CIVIL (2015) and analyzed through with non-linear dynamic and incremental dynamic analyses, using a suite of bridge-specific natural spectrum compatible ground motion records. Seismic responses of shear key, bearing pad, expansion joint and pier components of each bridges were recorded during analysis and retrieved for performance based analysis. Fragility curves were developed for the bearing pads, shear key, expansion joint and pier of the bridges that first reach ultimate limit state. Dynamic analysis and the derived fragility curves show that ultimate limit state of bearing pads, shear keys and expansion joints of the bridges exceed first, followed by the piers ultimate limit state for all the three bridges. Mean collapse capacities computed for all the components indicated that bearing pads, expansion joints, and shear keys exceed the ultimate limit state at lowest seismic intensities.

MEASUREMENT AND SIMULATION OF EQUATORIAL IONOSPHERIC PLASMA BUBBLES TO ASSESS THEIR IMPACT ON GNSS PERFORMANCE

  • Tsujii, Toshiaki;Fujiwara, Takeshi;Kubota, Tetsunari;Satirapod, Chalermchon;Supnithi, Pornchai;Tsugawa, Takuya;Lee, Hungkyu
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.30 no.6_2
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    • pp.607-613
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    • 2012
  • Ionospheric anomaly is one of the major error sources which deteriorate the GNSS performance. In the equatorial region, effects of the ionospheric plasma bubbles are of great interest because they are pretty common phenomena, especially in the period of the high solar activity. In order to evaluate the GNSS performance under circumstance of the bubbles, an ionospheric scintillation monitor has been developed and installed in Bangkok, Thailand. Furthermore, a model simulating the ionospheric delay and scintillation due to the bubbles has been developed. Based on these developments, the effects of the simulated plasma bubbles are analyzed and their agreement with the real observation is demonstrated. An availability degradation of the GPS ground based augmentation system (GBAS) caused by the bubbles is exampled in details. Finally, an integrated GPS/INS approach based on the Doppler frequency is proposed to remedy the deterioration.