• Title/Summary/Keyword: two-time-scale system

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Multiple-valued FFT processor design using current mode CMOS (전류 모드 CMOS를 이용한 다치 FFT 연산기 설계)

  • Song, Hong-Bok;Seo, Myung-Woong
    • Journal of the Korean Institute of Intelligent Systems
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    • v.12 no.2
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    • pp.135-143
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    • 2002
  • In this study, Multi-Values Logic processor was designed using the basic circuit of the electric current mode CMOS. First of all, binary FFT(Fast courier Transform) was extended and high-speed Multi-Valued Logic processor was constructed using a multi valued logic circuit. Compared with the existing two-valued FFT, the FFT operation can reduce the number of transistors significantly and show the simplicity of the circuit. Moreover, for the construction of amount was used inside the FFT circuit with the set of redundant numbers like {0, 1, 2, 3}. As a result, the defects in lines were reduced and it turned out to be effective in the aspect of normality an regularity when it was used designing VLSI(Very Large Scale Integration). To multiply FFT, the time and size of the operation was used toed as LUT(Lood Up Table).

Biohydrogen Production from Carbon Monoxide and Water by Rhodopseudomonas palustris P4

  • Oh You-Kwan;Kim Yu-Jin;Park Ji-Young;Lee Tae Ho;Kim Mi-Sun;Park Sunghoon
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.10 no.3
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    • pp.270-274
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    • 2005
  • A reactor-scale hydrogen (H2) production via the water-gas shift reaction of carbon monoxide (CO) and water was studied using the purple nonsulfur bacterium, Rhodopseudomonas palustris P4. The experiment was conducted in a two-step process: an aerobic/chemoheterotrophic cell growth step and a subsequent anaerobic $H_2$ production step. Important parameters investigated included the agitation speed. inlet CO concentration and gas retention time. P4 showed a stable $H_2$ production capability with a maximum activity of 41 mmol $H_2$ g $cell^{-1}h^{-1}$ during the continuous reactor operation of 400 h. The maximal volumetric H2 production rate was estimated to be 41 mmol $H_2 L^{-1}h^{-1}$, which was about nine-fold and fifteen-fold higher than the rates reported for the photosynthetic bacteria Rhodospirillum rubrum and Rubrivivax gelatinosus, respectively. This is mainly attributed to the ability of P4 to grow to a high cell density with a high specific $H_2$ production activity. This study indicates that P4 has an outstanding potential for a continuous H2 production via the water-gas shift reaction once a proper bioreactor system that provides a high rate of gas-liquid mass transfer is developed.

A Role of Serum-Based Neuronal and Glial Markers as Potential Predictors for Distinguishing Severity and Related Outcomes in Traumatic Brain Injury

  • Lee, Jae Yoon;Lee, Cheol Young;Kim, Hong Rye;Lee, Chang-Hyun;Kim, Hyun Woo;Kim, Jong Hyun
    • Journal of Korean Neurosurgical Society
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    • v.58 no.2
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    • pp.93-100
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    • 2015
  • Objective : Optimal treatment decision and estimation of the prognosis in traumatic brain injury (TBI) is currently based on demographic and clinical predictors. But sometimes, there are limitations in these factors. In this study, we analyzed three central nervous system biomarkers in TBI patients, will discuss the roles and clinical applications of biomarkers in TBI. Methods : From July on 2013 to August on 2014, a total of 45 patients were included. The serum was obtained at the time of hospital admission, and biomarkers were extracted with centrifugal process. It was analyzed for the level of S-100 beta (S100B), glial fibrillary acidic protein (GFAP), and ubiquitin carboxy-terminal hydrolase-L1 (UCH-L1). Results : This study included 33 males and 12 females with a mean age of 58.5 (19-84) years. TBI patients were classified into two groups. Group A was severe TBI with Glasgow Coma Scale (GCS) score 3-5 and Group B was mild TBI with GCS score 13-15. The median serum concentration of S100B, GFAP, and UCH-L1 in severe TBI were raised 5.1 fold, 5.5 fold, and 439.1 fold compared to mild injury, respectively. The serum levels of these markers correlated significantly with the injury severity and clinical outcome (p<0.001). Increased level of markers was strongly predicted poor outcomes. Conclusion : S100B, GFAP, and UCH-L1 serum level of were significantly increased in TBI according to severity and associated clinical outcomes. Biomarkers have potential utility as diagnostic, prognostic, and therapeutic adjuncts in the setting of TBI.

Study of the Rheological Properties of a Fermentation Broth of the Fungus Beauveria bassiana in a Bioreactor Under Different Hydrodynamic Conditions

  • Nunez-Ramirez, Diola Marina;Medina-Torres, Luis;Valencia-Lopez, Jose Javier;Calderas, Fausto;Lopez-Miranda, Javier;Medrano-Roldan, Hiram;Solis-Soto, Aquiles
    • Journal of Microbiology and Biotechnology
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    • v.22 no.11
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    • pp.1494-1500
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    • 2012
  • Fermentation with filamentous fungi in a bioreactor is a complex dynamic process that is affected by flow conditions and the evolution of the rheological properties of the medium. These properties are mainly affected by the biomass concentration and the morphology of the fungus. In this work, the rheological properties of a fermentation with the fungus Beauveria bassiana under different hydrodynamic conditions were studied and the rheological behavior of this broth was simulated through a mixture of carboxymethyl cellulose sodium and cellulose fibers (CMCNa-SF). The bioreactor was a 10 L CSTR tank operated at different stir velocities. Rheological results were similar at 100 and 300 rpm for both systems. However, there was a significant increase in the viscosity accompanied by a change in the consistence index, calculated according to the power law model, for both systems at 800 rpm. The systems exhibited shear-thinning behavior at all stir velocities, which was determined with the power law model. The mixing time was observed to increase as the cellulose content in the system increased and, consequently, the efficiency of mixing diminished. These results are thought to be due to the rheological and morphological similarities of the two fungal systems. These results will help in the optimization of scale-up production of these fungi.

Case Studies on Freezing Rain over the Korean Peninsula Using KLAPS (KLAPS를 이용한 한반도 어는비 사례 연구)

  • Kwon, Hui-Nae;Byun, Hi-Ryong;Park, Chang-Kyun
    • Atmosphere
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    • v.25 no.3
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    • pp.389-405
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    • 2015
  • In this study, the occurrence circumstances of 3 cases (12 Jan 2006, 11 Jan 2008, 22 Feb 2009) when the freezing rain was observed at more than two observatories in a day with more than three times each observatory, were investigated. Following the advanced study about the same cases, we have tried to find more delicate differences in using the Korea Local Analysis and Prediction System (KLAPS; 5 km reanalysis data) that has the smallest grid scale at current situation. As results, three common characteristics are found: (1) Just before the occurrence of the freezing rain, the wind direction was consistently continuous and the wind speed was constant or gradually increased for at least 3 hr more. (2) Surface air temperature (Relative humidity) was respectively $3.08^{\circ}C$ (28.76%), $0.47^{\circ}C$ (50.07%) and $-3.60^{\circ}C$ (71.07%) 3 hr ago to break out the freezing rain. It means the freezing rain occurs in a wide range of atmospheric environments. However, the closer it got to the occurrence time of the freezing rain, the closer the surface air temperature was to $0^{\circ}C$, and the bigger the humidity of the surface air was. (3) The liquid precipitation formed in the upper atmosphere, met a cold advection bellower than 950 hPa level and suspected to be changed to the super-cooled condition.

Seismic retrofitting by base-isolation of r.c. framed buildings exposed to different fire scenarios

  • Mazza, Fabio;Mazza, Mirko
    • Earthquakes and Structures
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    • v.13 no.3
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    • pp.267-277
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    • 2017
  • Base-isolation is now being adopted as a retrofitting strategy to improve seismic behaviour of reinforced concrete (r.c.) framed structures subjected to far-fault earthquakes. However, the increase in deformability of a base-isolated framed building may lead to amplification in the structural response under the long-duration horizontal pulses of high-magnitude near-fault earthquakes, which can become critical once the strength level of a fire-weakened r.c. superstructure is reduced. The aim of the present work is to investigate the nonlinear seismic response of fire-damaged r.c. framed structures retrofitted by base-isolation. For this purpose, a five-storey r.c. framed building primarily designed (as fixed-base) in compliance with a former Italian seismic code for a medium-risk zone, is to be retrofitted by the insertion of elastomeric bearings to meet the requirements of the current Italian code in a high-risk seismic zone. The nonlinear seismic response of the original (fixed-base) and retrofitted (base-isolated) test structures in a no fire situation are compared with those in the event of fire in the superstructure, where parametric temperature-time curves are defined at the first level, the first two and the upper levels. A lumped plasticity model describes the inelastic behaviour of the fire-damaged r.c. frame members, while a nonlinear force-displacement law is adopted for the elastomeric bearings. The average root-mean-square deviation of the observed spectrum from the target design spectrum together with a suitable intensity measure are chosen to select and scale near- and far-fault earthquakes on the basis of the design hypotheses adopted.

Prevalence and Clinical Characteristics of Sexual Exhibitionism and Frotteurism in Korea : Preliminary Study (성적 노출증 및 접촉도착증의 유병율 및 임상특성 : 예비연구)

  • Park, Sun Hwa;Kwon, Seok Hyeon;Wang, Tae Jong;Hong, Jung Min;Kim, Eun Bi;Meng, Jung Won;Lim, Myung Ho
    • Anxiety and mood
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    • v.11 no.1
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    • pp.19-25
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    • 2015
  • Objective : The current study investigated the prevalence and clinical characteristics of sexual exhibitionism and frotteurism, which was conducted for the first time in Korea. Methods : Among 568 total subjects (mean age $19.28{\pm}5.0$ year), 109 were victims of sexual exhibitionism (19.2%, VSE) of which 57 were females (91.9 percent) ; and 57 were victims of sexual frotteurism (10.9%, VSF) of which 57 were females (91.9%). The participants completed the self-reported scale for epidemiological and clinical characteristics. Results : Incident frequencies of above two times of VSE and VSF were 49 (50.0%) and 20 (32.3%), respectively. Incident locations of VSE were school/office 37 (33.3%), street 28 (25.6%), and near home 20 (18.3%). Also, incident locations of VSE were inside of bus 12 (19.3%), subway 12 (19.3%), subway/bus station 8 (12.9%), near home 8 (12.9%), and school/office 7 (11.3%). Notifying rate of VSE and VSF to the police were 7.3% and 0%, respectively. Also, notifying rate of VSE and VSF to family or friends were 72.5% and 58.1%, respectively Conclusion : These results suggested that VSE and VSF had a common prevalence, which could be different from behavioral and emotional characteristics of a control group ; and the victims were shown to require an active intervention by supportive social system.

Influence of Boreal Summer Intraseasonal Oscillation on the 2016 Heat Wave over Korea (한반도 2016년 폭염에 여름철 계절안진동이 미친 영향)

  • Lee, June-Yi;Kim, Hae-Jeong;Jeong, Yoo-Rim
    • Atmosphere
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    • v.29 no.5
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    • pp.627-637
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    • 2019
  • Severe and long-lasting heat waves over Korea and many regions in the Northern Hemisphere (NH) during the 2016 summer, have been attributed to global warming and atmospheric teleconnection coupled with tropical convective activities. Yet, what controls subseasonsal time scale of heat wave has not been well addressed. Here we show a critical role of two dominant boreal summer intraseasonal oscillation (BSISO) modes, denominated as BSISO1 and BSISO2, on modulating temporal structure of heat waves in the midst of similar climate background. The 2016 summer was characterized by La Nina development following decay of strong 2015/2016 El Nino. The NH circumglobal teleconnection pattern (CGT) and associated high temperature anomalies and heat waves were largely driven by convective activity over northwest India and Pakistan during summer associated with La Nina development. However, the heat wave event in Korea from late July to late August was accompanied by the phase 7~8 of 30~60-day BSISO1 characterized by convective activity over the South China Sea and Western North Pacific and anticyclonic circulation (AC) anomaly over East Asia. Although the 2010 summer had very similar climate anomalies as the 2016 summer with La Nina development and CGT, short-lasting but frequent heat waves were occurred during August associated with the phase 1~2 of 10~30-day BSISO2 characterized by convective activity over the Philippine and South China Sea and AC anomaly over East Asia. This study has an implication on importance of BSISO for better understanding mechanism and temporal structure of heat waves in Korea.

Improving RFID Anti-Collision Algorithms with Multi-Packet Reception (다중 패킷 수신을 이용한 RFID 충돌방지 알고리즘의 성능 향상)

  • Lee, Jeong-Keun;Kwon, Taek-Young;Choi, Yang-Hee;Kim, Kyung-Ah
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.11A
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    • pp.1130-1137
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    • 2006
  • One of the important performance issues in large-scale RFID systems is to resolve collisions among responses from RFID tags. Considering two do facto anti-collision solutions, namely the binary-tree splitting algorithm and the Slotted-Aloha algorithm, we propose to use multi-packet reception (MPR) capability to enhance the RFID tag reading rate (i.e., throughput). MPR allows an RFID reader to receive multiple reponses transmitted by tags at the same time. We analyze the effect of MPR capability in the above anti-collision algorithms, which is also validated by simulation. The analysis and simulation results show that RFID reader antenna design and signal separation techniques play an important role in improving RFID system performance with MPR capability.

Passive UHF RFID Propagation Characteristics and Reconsideration of Link budget on Practical Communication Area (수동형 UHF RFID 인터페이스에 대한 Link budget의 재해석 및 전파 환경 요소 분석)

  • Jung, Jin-Woo;Park, Kyoung-Tae;Roh, Hyoung-Hwan;Park, Jun-Seok;Kim, Hyeong-Seok
    • 한국정보통신설비학회:학술대회논문집
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    • 2008.08a
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    • pp.469-472
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    • 2008
  • In this paper, we discuss the recent trends on the passive UHF RFID tag chip design techniques and several important system parameters. We also summarize link budget studies on both conventional and modem UHF RFID communications. The paper highlights the reverse link limited case, which has known to be the minor concern if reader continuous wave (CW) can reach the tag in sufficient level. This makes sense when the tag sensitivity is rather high (over 10-12${\mu}W$); however, since the tag chip fabrication technologies have been developed by time, the tag chip threshold levels are now less-dominant in determining link margin. If the tag limitation can be alleviated, the forward link limited case can be resolved; thus, we rather focus on the path-loss problem. Since the path-losses are still exist in both forward and reverse links, and it can be doubled while CW travels the reader-tag-reader path because forward link and reverse link are on the same distance. Consider if reader receiver sensitivity is very high in the worst case. In this case, weaken tag response (i.e., backscatters) cannot reach the level that reader receiver can process tag data; bit-error rate can be higher. Overall, backscatter levels should be high enough so that reader receiver can correctly function. After discussing link budget, we carried out practical measurements on fading effects between two circularly polarized UHF RFID antennas in a small scale area.

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