• Title/Summary/Keyword: DWC

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Optimal Design of Solvent Recovery Process with Dividing Wall Column for Film Making Process (분리벽형 증류탑을 적용한 필름공정의 폐용매 회수공정 최적설계)

  • Lee, Seung-Hyun;Zo, Moon-Shin;Lee, Moon-Yong
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.12
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    • pp.1209-1214
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    • 2006
  • This paper presents an application of Dividing Wall Column(DWC) to the recovery of the waste solvent from the film making processes. The waste solvent feed contains MEK(Methyl-Ethyl-Ketone), Toluene, Cyclohexanone, and water. The commercial software $HYSYS^{TM}$ was used for rigorous simulation and analysis. Sensitivity analysis for several major design variables were carried out to achieve the optimal design of the process. Distribution of the internal vapor and liquid flows to the prefractionator and main sections is shown to be the most dominant design factor for energy saving efficiency in the DWC process. The simulation results also show that the solvent recovery process using the DWC significantly improves both the energy efficiency and the compactness of the solvent recovery process.

Starch Properties of Daehak Waxy Corn with Different Harvest Times (수확시기에 따른 대학찰옥수수의 전분특성)

  • Lee, Sang-Hoon;Hwang, In-Guk;Kim, Hyun-Young;Lee, Ha-Kyu;Lee, Seong-Hee;Woo, Seon-Hee;Lee, Jun-Soo;Jeong, Heon-Sang
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.4
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    • pp.573-579
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    • 2010
  • This study investigated starch properties of 'Daehak waxy corn (DWC)' with different harvest times. The DWCs were harvested at 4 days before suitable time (BST), suitable time (ST) and 4 days after suitable time (AST). As harvest time was delayed, starch yield and amylopectin content of DWC starch increased from 43.21 to 52.73%, and from 90.79 to 92.83% based on dry weight, respectively. As harvest time was postponed, enzymatic digestibility and water solubility of DWC starch decreased from 81.43 to 80.58%, and from 10.23 to 9.23%. However, water binding capacity and swelling power of DWC starch increased from 227.94 to 244.88%, and from 24.75 to 29.74%, respectively. Retrogradation viscosity of starch was the lowest in DWC harvested at AST. There was a high correlation coefficient among starch properties of DWC, such as starch yield, enzymatic digestibility, water binding capacity, swelling power, water solubility and retrogradation viscosity (p<0.01). As harvest time was deferred, enzymatic digestibility, water solubility and retrogradation viscosity decreased; however, amylopectin content increased, and water binding capacity and swelling power significantly increased with increasing amylopectin content.

Collaborative Wideband Spectrum Sensing with Distance Based Weight Combining for Cognitive Radio System (인지무선 시스템을 위한 거리기반 가중결합을 이용한 협력 광대역 스펙트럼 센싱)

  • Lee, Mi-Sun;Kim, Yoon-Hyun;Kim, Jin-Young
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.1
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    • pp.37-43
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    • 2012
  • In this paper, we analysis wideband spectrum sensing with distance based weight combining for Cognitive Radio (CR) systems. CR systems is implemented the spectrum of the Primary User(PU) by using a energy detection method. Threshold is determined in accordance with the constant false alarm rate (CFAR) algorithm for energy detection. The signal of PU is BPSK signal and the wireless channel between a PU and CR systems is modeled as Gaussian channel. From the simulation results, the wideband sensing with distance based and Distance based weight Combing (DWC) methods shows higher spectrum sensing performance than single CR user spectrum sensing.

Application of a Divided-Wall Column for the Trichlorosilane Refining Process (삼염화실란 정제공정에서의 분리벽형 증류탑 적용)

  • Hong, Seung-Taek;Lee, Moon-Yong
    • Clean Technology
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    • v.16 no.1
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    • pp.64-70
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    • 2010
  • In this study, we suggest the application of the divided-wall column (DWC) to the existing trichlorosilane(TCS) purification process in the commercial polysilicon manufacturing process. Using Aspen HYSYS V7.1, an extensive simulation study was carried out for the analysis of the energy consumptions and capital cost for the conventional sequential distillation configuration and the DWC for producing a given purity and yield of trichlorosilane. As a result, it is shown that the DWC saves the separation energy by 61% and the equipment cost by 58% compared with the conventional distillation process.

대웅세파(DWC-751)의 일반독성 및 특수독성연구

  • 정규찬;박정식;하광원;유영호;연재덕;이제원;강진석
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1993.04a
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    • pp.105-105
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    • 1993
  • 랫드 및 마우스에 1회 경구 및 정맥투여하였을때의 급성독성을 관찰한 결과 랫드에서 급성경구 시험결과의 LD$_{60}$치는 암수 각각 5,000mg/kg 이상이었으며, 급성정맥시험 결과의 LD$_{50}$치는 수컷에서 1,151mg/kg, 암컷에서 1,184mg/kg이었다. 마우스에서 급성경구시험 결과의 LD$_{60}$치는 암수 각각 5,000mg/kg 이상이었으며 급성정맥시험 결과의 LD$_{50}$치는 수컷에서 2,698mg/kg, 암컷에서 2,833mg/kg이었다. Sal. typhimurium을 이용한 돌연변이시험, 마우스를 이용한 소핵시험, 배양세포를 이용한 염색체 이상 시험을 실시한 결과 모두 음성으로 나왔으므로 DWC-751의 돌연변이 유발능은 없는 것으로 나타났다.타났다.

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The Correlation between Ultrasonographic Findings of Median Nerve and Clinical Scale and Electrodiagnotic Data in Carpal Tunnel Syndrome (수근관 증후군에서 임상양상척도 및 신경전기진단 결과와 정중신경 초음파 소견의 상관관계)

  • Lee, Gyu-Ho;Kim, Sei-Joo;Yoon, Joon-Shik;Park, Byung-Kyu;Cho, Jung-Mo;Jung, Jin-Seok
    • Annals of Clinical Neurophysiology
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    • v.12 no.2
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    • pp.55-60
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    • 2010
  • Background: The aim of this study is to identify the correlation between ultrasonographic findings of median nerve and clinical scale and electrophysiologic data in carpal tunnel syndrome. Methods: Forty three patients (79 hands) with electrophysiologically confirmed carpal tunnel syndrome were evaluated. Clinical symptoms were examined by Historical-Objective (Hi-Ob) scale. Electrophysiologic data and Padua scale were used for severity of electrophysiology. In ultrasonographic study, cross sectional area and flattening ratio of median nerve were measured at distal wrist crease level (DWC), 1cm proximal to distal wrist crease level, and 1cm distal to distal wrist crease level. The correlation between Hi-Ob scale, electrophysiologic data and ultrasonography was measured with Spearman rank test. Results: The mean Hi-Ob scale was 2.4. Mean Padua scale was 4.0. In ultrasnonographic study, cross sectional area and flattening ratio were $0.112\;cm^2{\pm}0.025$ and $3.0{\pm}0.6$ at 1cm proximal to DWC level, $0.118{\pm}0.026\;cm^2$ and $2.9{\pm}0.4$ at DWC level, and $0.107{\pm}0.032\;cm^2$ and $3.0{\pm}0.4$ at 1 cm distal to DWC level. Hi-Ob scale was not correlated with cross sectional area and flattening ratio of median nerve. Hi-Ob scale was correlated with Padua scale positively (r=0.44) and correlated with amplitudes of CMAP and SNAP, negatively (r=-0.33; r=-0.30). Cross sectional area of median nerve was significantly correlated with Padua scale, amplitudes and latencies of CMAP and amplitudes of SNAP. Conclusions: Ultrasonographic findings of median nerve and electrodiagnostic data had statistically significant correlation. Consequently, ultrasonography could be an adjunctive method in diagnosis of carpal tunnel syndrome.

Risk Analysis of Aircraft Operations in Seoul TMA Based on DAA Well Clear Metrics using Recorded ADS-B Data (ADS-B 데이터를 이용한 서울 TMA에서의 DAA Well Clear 기반 위험도 분석)

  • Lee, Hak-Tae;Lee, Hyeonwoong
    • Journal of Advanced Navigation Technology
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    • v.24 no.6
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    • pp.527-532
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    • 2020
  • Seoul terminal maneuvering area (TMA) that includes Incheon International Airport (ICN) and Gimpo International Airport is a very congested airspace with around 1,000 daily flights and the airspace blocked at the boundary between Incheon flight information region (FIR) and Pyongyang FIR. Consequently, with frequency radar vectorings, separation assurance in this airspace is complicated thus resulting in higher controller workload. In this paper, the conflict and collision risks in Seoul TMA are analyzed using recorded ADS-B data for past three years. Using the recorded trajectories, original flight plan procesures and routes are reconstructed and the risks are quantified using detect and avoid well clear (DWC) metric that is developed for large unmanned aircraft system. The region west of ICN was found to be the highest risk area regardless of the runway directions. In addition, merge and crossing points between procedures displayed relatively high risks.

Risk Analysis of Flight Procedures at Incheon International Airport and Gimpo International Airport (인천국제공항과 김포국제공항의 비행 절차 위험도 분석)

  • Lee, Hyeonwoong;Lee, Hak-Tae
    • Journal of Advanced Navigation Technology
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    • v.24 no.6
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    • pp.500-507
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    • 2020
  • This paper presents a risk assessment methodology for standard flight procedures using recorded automatic dependent surveillance-broadcast (ADS-B) data. Utilizing the proposed methodology, the results of risk analyses in RKSI (incheon international airport) and RKSS (gimpo international airport) using trajectories that are regenerated based on 100 days of ADS-B data are presented. For the risk metric, detect and avoid well clear (DWC) is used. With this index, each procedure was evaluated for the sections with highest level of risk. Among the standard instrument departure (SID) of RKSI, the section between SI712 and RANOS of RNAV BOPTA 1L showed the highest level of risk. For the standard terminal arrival route (STAR) of RKSI, section between SI947 and DANAN of RNAV GUKDO 1N wasthe one with the highest level of risk. For RKSS, the segment between SS726 and SS727 of RNAV BULTI 1X and the segment between KAKSO and KALMA of RNAV OLMEN 1D showed the highest level of risk among the SIDs and STARs, respectivly.

2019 Incheon FIR Aerial Collision Risk Analysis (2019년도 인천 FIR 공중 충돌 위험도 분석)

  • Jae-young Ryu;Hyeonwoong Lee;Bae-Seon Park;Hak-Tae Lee
    • Journal of Advanced Navigation Technology
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    • v.25 no.6
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    • pp.476-483
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    • 2021
  • In order to maintain the safety of the airspace with ever increasing traffic volume, it is necessary to thoroughly analyze the collision risk with the current data. In this study, collision risk analysis was conducted using Detect and Avoid (DAA) Well-Clear (DWC) metrics, risk induces developed for the DAA systems of unmanned aerial vehicles. All flights in year 2019 that flew within the Incheon Flight Information Region (FIR) boundary were analyzed using the recorded Automatic Dependent Surveillance-Broadcast(ADS-B) data. High risk regions as well as trends by airports and seasons were identified. The results indicate that the risk is higher around the congested area near Incheon International Airport and Gimpo International Airport. Seasonally, the risk was highest in August that coincides with the Summer vacation period. The result will be useful for the baseline data for various aviation safety enhancement activities such as revision of routes and procedures and training of the field specialists.