• Title/Summary/Keyword: Blocking ratio

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Active Object Tracking System for Intelligent Video Surveillance (지능형 비디오 감시를 위한 능동적 객체 추적 시스템)

  • Park, Ho-Sik
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.7 no.2
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    • pp.82-85
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    • 2014
  • It is helpful to use Intelligent Video Surveillance to replace and supplement the demerit which can possibly occur due to the mistake that can be made by human management. To accomplish this, it is essential that the system should digitalize image information from surveillance camera so that the system, itself, can be able to locate a object and to analyze the pattern of the object. Also, it is imperative that the system should have ability to operate a alarm and a entrance blocking system and to notify a situation to a security manager. Zooming a small object form a screen, however, requires a exact zooming ratio of the object and a shift of centric coordinate. In this paper, It is able to locate and observe closely a object from flexible background, regardless of the distance, by calculating a zooming ratio according to object moment, pan coordinate, and tilt coordinate.

Design of Heliostat Field for 200kW Tower Type Solar Thermal Power Plant (200kW 탑형 태양열발전시스템의 Heliostat Field 설계)

  • Park, Young Chil
    • Journal of the Korean Solar Energy Society
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    • v.32 no.5
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    • pp.41-51
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    • 2012
  • Heliostat field is the most important subsystem in the tower type solar thermal power plant since its optical performance affects the total system efficiency most significantly while the construction cost of it is the major part of total construction cost in such a power plant. Thus a well designed heliostat field to maximize the optical efficiency as well as to minimize the land usage is very important. This work presents methodology, procedures and result of heliostat filed design for 200kW solar thermal power plant built recently in Daegu, Korea. A $2{\times}2(m)$ rectangular shaped receiver located at 43(m) high and tilted $28^{\circ}$ toward heliostat field, 450 of heliostats of which the reflective surface is formed by 4 of $1{\times}1(m)$ flat plate mirror facet, and the land area having about $140{\times}120(m)$ size are used to form the heliostat field. A procedure to deploy 450 heliostats in radial staggered nonblocking formation is developed. Also the procedures to compute the cosine effect, intercept ratio, blocking and shading ratio in the field are developed. Finally the heliostat filed is designed by finding the optimal radial distance and azimuthal spacing in radial staggered nonblocking formation such that the designed heliostat field optical efficiency could be maximized. The designed heliostat field has 77% of annual average optical efficiency, which is obtained by annually averaging the optical efficiencies computed between the time of where sun elevation angle becomes $10^{\circ}$ after sunrise and the time of where sun elevation angle becomes $10^{\circ}$ before sunset in each day.

Performance Comparison of CDMA and TDMA protocols in radio access system for Integrated Voice/Data Services (음성 및 데이터서비스를 위한 무선접속시스템에서 CDMA와 TDMA방식의 성능비교)

  • 고종하;양영님;이정규
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.6A
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    • pp.820-831
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    • 1999
  • In this paper, we have compared the performance of a D-TDMA protocol with that of a CDMA protocol, in radio access system for integrated voice/data services.The D-TDMA protocol is based on a generic dynamic channel assignment approach to be followed a combination of “circuit mode” reservation for voice calls, along with dynamic first-come-first served assignment of remaining capacity for data messages. In the CDMA protocol, we have used the voice activity detection to reduce the interface power of other mobiles in internal and external cells, and analyzed the interference power ratio. Also we have computed BER(Bit Error Rate) by using this interference power ratio and evaluated voice blocking probability(voice packet loss probability) and data transmission delay, according to average data length and average data arrival rate.We have found the CDMA protocol achieves comparatively higher performance for short data length, regardless of data arrival rate. Otherwise, the data transmission delay of D-TDMA protocol is shorter than that of the CDMA protocol for long data message.

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Methanol Extract of Cassia mimosoides var. nomame Attenuates Myocardial Injury by Inhibition of Apoptosis in a Rat Model of Ischemia-Reperfusion

  • Lim, Sun-Ha;Lee, Jong-Won
    • Preventive Nutrition and Food Science
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    • v.17 no.3
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    • pp.177-183
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    • 2012
  • Interruption of blood flow through coronary arteries and its subsequent restoration triggers the generation of a burst of reactive oxygen species (ROS), leading to myocardial cell death. In this study, we determined whether a methanol extract of Cassia mimosoides var. nomame Makino could prevent myocardial ischemia-reperfusion injury. When radical scavenging activity of the extract was measured in vitro using its ${\alpha}$,${\alpha}$-diphenyl-${\beta}$-picrylhydrazyl (DPPH) radical quenching ability, the extract showed an activity slightly lower than that of ascorbic acid. Three days after oral administration of the extract (400 mg/kg/day) to rats, myocardial ischemia/reperfusion injury was generated by 30 min of ligation of the left anterior descending coronary artery (LAD), followed by 3 hr reperfusion. Compared with the vehicle-treated group, administration of the extract significantly reduced infarct size (IS) (ratio of infarct area to area at risk) in the extract-treated group by 28.3%. Reduction in the cellular injury was mediated by attenuation of Bax/Bcl-2 ratio by 33.3%, inhibition of caspase-3 activation from procaspase-3 by 40%, and subsequent reduction in the number of apoptotic cells by 66.3%. These results suggest that the extract attenuates myocardial injury in a rat model of ischemia-reperfusion by scavenging ROS, including free radicals, and consequently blocking apoptotic cascades. Therefore, intake of Cassia mimosoides var. nomame Makino might be beneficial for preventing ischemic myocardial injury.

Selective Separation of Hydrogen from Gas Mixture using LaNi5 (LaNi5를 이용한 혼합기체로부터 수소의 선택적 분리)

  • Sun, Yang Kook;Nahm, Kee Suk;Lee, Wha Young
    • Transactions of the Korean hydrogen and new energy society
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    • v.1 no.1
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    • pp.15-23
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    • 1989
  • The selective separation of hydrogen from gas mixture containing hydrogen was experimentally studied using $LaNi_5$. The capacity and the rate of hydrogen separation, the purity of recovered hydrogen and the optimum condition of the regeneration of deactivated $LaNi_5$ were investigated. The separation rate and the recovery ratio of hydrogen were slowly decreased with the increase of the number of hydrogen absorption cycle. It was found that this result comes from the deactivation of $LaNi_5$ partly because of the blocking of hydrocarbon compounds in the $LaNi_5$ lattice and partly because of the poisoning of $LaNi_5$ surface by carbon monoxide contained in the gas mixture. The optimum condition for the regeneration of deactivated $LaNi_5$ was obtained by heating in a vacuum to about 637 K. The recovery ratio of hydrogen at the optimum condition was observed to be about 80%. The rates of hydrogen separation were measured in the ${\alpha}$-phase and two phase regions. The rate equations could be expressed as follows ; ${\alpha}$ - phase : $$-\frac{dP{_{H_2}}}{dt}=9.836{\times}10^{-3}(P{_{H_2}}_{-P_{eq}})$$ two phase region : $$-\frac{dP_{H{_2}}}{dt}=1.6909{\times}10^2\exp(-17560/RT)(P{_{H_2}}_{-P_{eq}})$$.

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Apple pectin, a dietary fiber, ameliorates myocardial injury by inhibiting apoptosis in a rat model of ischemia/reperfusion

  • Lim, Sun Ha;Kim, Mi Young;Lee, Jongwon
    • Nutrition Research and Practice
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    • v.8 no.4
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    • pp.391-397
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    • 2014
  • BACKGROUND/OBJECTIVE: Myocardial cell death due to occlusion of the coronary arteries leads to myocardial infarction, a subset of coronary heart disease (CHD). Dietary fiber is known to be associated with a reduced risk of CHD, the underlying mechanisms of which were suggested to delay the onset of occlusion by ameliorating risk factors. In this study, we tested a hypothesis that a beneficial role of dietary fiber could arise from protection of myocardial cells against ischemic injury, manifested after occlusion of the arteries. MATERIALS/METHODS: Three days after rats were fed apple pectin (AP) (with 10, 40, 100, and 400 mg/kg/day), myocardial ischemic injury was induced by 30 min-ligation of the left anterior descending coronary artery, followed by 3 hr-reperfusion. The area at risk and infarct area were evaluated using Evans blue dye and 2,3,5-triphenyltetrazolium chloride (TTC) staining, respectively. DNA nicks reflecting the extent of myocardial apoptosis were assessed by TUNEL assay. Levels of cleaved caspase-3, Bcl-2, and Bax were assessed by immunohistochemistry. RESULTS: Supplementation of AP (with 100 and 400 mg/kg/day) resulted in significantly attenuated infarct size (IS) (ratio of infarct area to area at risk) by 21.9 and 22.4%, respectively, in the AP-treated group, compared with that in the control group. This attenuation in IS showed correlation with improvement in biomarkers involved in the apoptotic cascades: reduction of apoptotic cells, inhibition of conversion of procaspase-3 to caspase-3, and increase of Bcl-2/Bax ratio, a determinant of cell fate. CONCLUSIONS: The findings indicate that supplementation of AP results in amelioration of myocardial infarction by inhibition of apoptosis. Thus, the current study suggests that intake of dietary fiber reduces the risk of CHD, not only by blocking steps leading to occlusion, but also by protecting against ischemic injury caused by occlusion of the arteries.

A Study on the Cover Property of Offshore Reinforced Concrete Structure (내구성 해양 RC 구조물의 철근 피복적정성에 관한 연구)

  • Im, Jung-Soon;Bahng, Yun-Suk;Jo, Jae-Byung
    • Journal of the Korean Society of Hazard Mitigation
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    • v.4 no.3 s.14
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    • pp.73-81
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    • 2004
  • On this study, durability decreasing element caused by salt damage was analyzed elementally and studied with the data of the inside and outside in the country. The design strength and water-cement ratio according to diffusion coefficients of chloride were applied to Fick's diffusion equation. The required over depended on environmental conditions is estimated with endurance period, and the influences on cover according to the transformation of the each parameter were investigated. In consequence, if water-cement ratio decreases and design strength increases, it shows that slowing infiltration velocity of chloride ion can decrease required cover. Especially, it is more effective to use Portland blast-furnace slag cement into high strength concrete in the splash zone environmental conditions in blocking the diffusion of chloride ion. As the result, in the case of the offshore concrete structure needed high durability, it is needed to increase cover($3cm{\sim}8cm$) than minimum standard cover(8cm) according to environmental conditions.

Performance Analysis of Mobile Multi-hop Relay Uplink System in Multicell Environments (멀티셀 환경에서 Mobile Multi-hop Relay 상향링크 시스템의 성능 분석)

  • Kim, Seung-Yeon;Kim, Se-Jin;Lee, Hyong-Woo;Ryu, Seung-Wan;Cho, Choong-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.4A
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    • pp.394-400
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    • 2010
  • Mobile Multi-hop Relaying (MMR) system can provide increased system capacity of wireless access network by coverage extension and enhanced transmission rate within the Base Station (BS) coverage area. The previous researches for the MMR system with a non-transparent mode Relay Station (RS) do not consider channel selection procedure of Mobile Station (MS), co-channel interference and Multi-hop Relay Base Station (MR-BS) coverage and RS coverage ratio in MMR system. In this paper, we investigate the performance of MMR uplink system in multicell environments with various topologies. The performance is presented in terms of call blocking probability, channel utilization, outage probability and system throughput by varying offered load. It is found that, for certain system parameters, the MMR uplink system achieve the maximum system throughput when MR-BS coverage to RS coverage ratio is 7.

The analysis of leakage current of InGaAsP/InP PBH-LD fabricated by LPE (LPE 방법으로 제작된 InGaAsP/InP PBH-LD의 누설전류해석)

  • 최미숙;김정호;홍창희
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.11a
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    • pp.481-485
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    • 2002
  • In this study, we fabricated the PBH-LD by meltback method using the LPE. The PBH-LDs are analyzed the leakage current that flows through leakage current path like the p-n diode and p-n-p-n current blocking layer. We observed the variation of threshold current with the leakage width $W_{ι}$. As a consequence, we confirmed that the threshold current became low in the decrease of the leakage width and in the increase of the ratio of specific resistivity of leakage region to active region. We also compared between the calculated threshold current in the absence of leakage region and the measured threshold current in the device. As a result, the ratio of specific resistivity was about 0.5 in the measured LDs, which have the width of a active layer of 1.4${\mu}{\textrm}{m}$ and leakage width of 0.6${\mu}{\textrm}{m}$.

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Single-Protein Molecular Interactions on Polymer-Modified Glass Substrates for Nanoarray Chip Application Using Dual-Color TIRFM

  • Kim, Dae-Kwang;Lee, Hee-Gu;Jung, Hyung-Il;Kang, Seong-Ho
    • Bulletin of the Korean Chemical Society
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    • v.28 no.5
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    • pp.783-790
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    • 2007
  • The immobilization of proteins and their molecular interactions on various polymer-modified glass substrates [i.e. 3-aminopropyltriethoxysilane (APTS), 3-glycidoxypropyltrimethoxysilane (GPTS), poly (ethylene glycol) diacrylate (PEG-DA), chitosan (CHI), glutaraldehyde (GA), 3-(trichlorosilyl)propyl methacrylate (TPM), 3'-mercaptopropyltrimethoxysilane (MPTMS), glycidyl methacrylate (GMA) and poly-l-lysine (PL).] for potential applications in a nanoarray protein chip at the single-molecule level was evaluated using prismtype dual-color total internal reflection fluorescence microscopy (dual-color TIRFM). A dual-color TIRF microscope, which contained two individual laser beams and a single high-sensitivity camera, was used for the rapid and simultaneous dual-color detection of the interactions and colocalization of different proteins labeled with different fluorescent dyes such as Alexa Fluor® 488, Qdot® 525 and Alexa Fluor® 633. Most of the polymer-modified glass substrates showed good stability and a relative high signal-to-noise (S/N) ratio over a 40-day period after making the substrates. The GPTS/CHI/GA-modified glass substrate showed a 13.5-56.3% higher relative S/N ratio than the other substrates. 1% Top-Block in 10 mM phosphate buffered saline (pH 7.4) showed a 99.2% increase in the blocking effect of non-specific adsorption. These results show that dual-color TIRFM is a powerful methodology for detecting proteins at the single-molecule level with potential applications in nanoarray chips or nano-biosensors.