Thermophotovoltaic power conversion using a superadiabatic radiant burner

Wu, H.,Kaviany, M.,Kwon, O.C. Elsevier 2018 APPLIED ENERGY Vol.209 No.-

<P>A new configuration of a 5-10 W thermophotovoltaic (TPV) device integrated with a porous superadiabatic radiant burner (SRB) is suggested and experimentally studied. The silicon carbide (SiC) SRB (emitter) consists of a small-pored upstream section (PM1) and a large-pored downstream section (PM2). PM1 is the section where the incoming fuel-air mixture is preheated internally and PM2 is the section where flame is established. Also, a separate preheater is attached on the SRB to externally recover heat from the exiting flue gas and preheat the inlet air for the burner, and radiation rods are embedded at the interface between the PM1 and PM2 to extract heat from the flame and transfer it to radiating disk surfaces. Radiation from the disk surface is used for the TPV power conversion, reaching gallium antimonide photovoltaic cells (PVCs) with proper quantum efficiencies (up to 80%) through a quartz plate for preventing direct convectional heat transfer from the exhaust gas onto the PVCs. Under optimized conditions, uniform radiation provides adequate TPV performance, particularly indicating reasonable emitter efficiencies (up to 32%) with the enhanced disk temperature even for fuel-lean condition. Thus, the present configuration of the SRB-integrated TPV device can be used in practical applications, avoiding high-level noise without any moving parts.</P>

Aqueous gelcasted ZrB₂-SiC foams derived from composite poring mechanisms

Wu, H.,Yin, J.,Li, Y.,Zhu, Y.,Liu, X.,Lee, S.H.,Wu, Y.,Huang, Z. Ceramurgica ; Elsevier Science Ltd 2016 CERAMICS INTERNATIONAL Vol.42 No.1

ZrB<SUB>2</SUB>-SiC foams were prepared from composite poring mechanisms of foaming and solid poring (PAA beads) by the application of a gelcasting technique. The porosities and microstructures of sintered bulks were tailored through changing the solids loading of slurries and the amount of added PAA beads. The increase in solid loading caused high viscosities of slurries, and thus resulted in the reduction of porosity and a tendency to form close pores. With increasing the amount of PAA beads, high porosities (up to 91.4%) and obvious connectivity improvement between bubble-derived pores emerged owing to efficient foaming and presence of bead-derived pores. As the porosity increased, the compressive strength (0.4-8.2MPa) decreased, and the gas permeability (9.7-62.1x10<SUP>-12</SUP>m<SUP>2</SUP>) augmented because of the effects of bead-derived pores and the increase in window number and size of bubble-bead pores.

Experiment on superadiabatic radiant burner with augmented preheating

Wu, H.,Kim, Y.J.,Vandadi, V.,Park, C.,Kaviany, M.,Kwon, O.C. Elsevier 2015 APPLIED ENERGY Vol.156 No.-

<P><B>Abstract</B></P> <P>A radiant porous burner with augmented preheating (i.e., superadiabatic radiant burner, SRB) is experimentally investigated. The porous alumina (Al<SUB>2</SUB>O<SUB>3</SUB>) burner with a square cross-section consists of a small-pored upstream section for internally preheating the incoming gas mixture, a large-pored downstream section for establishing flame, a preheater for externally recovering heat from the exiting flue gas and preheating the inlet air for the burner in addition to the internal heat recirculation in the small-pored upstream section, and radiation corridors for extracting heat from the flame and transferring it to radiating disk surfaces. Temperature distribution and combustion stability limits of flame in the SRB and the nitrogen oxide (NO<SUB>x</SUB>) and carbon monoxide (CO) emissions are measured. Results show that the SRB can be operated even at very fuel-lean condition because of the internal and external heat recirculation, showing blow-off and flash-back limits for a given fuel-equivalence ratio. It is observed that the superadiabatic radiation temperature on the disk surfaces is higher than the flue gas temperature at the same axial location, experimentally confirming the previous theoretical and computational results of SRBs. Improved performance of CO and NO<SUB>x</SUB> emissions compared with the conventional porous radiant burners also indicates that the SRB is acceptable for practical application.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Potential of superadiabatic radiant burners (SRBs) is experimentally confirmed. </LI> <LI> The SRB consists of two-layered porous media, a preheater and radiation rods. </LI> <LI> The SRB can be operated at very fuel-lean condition due to enhanced heat recovery. </LI> <LI> CO/NO<SUB>x</SUB> emissions are reduced compared with the conventional porous radiant burners. </LI> <LI> The SRB is acceptable for practical applications. </LI> </UL> </P>

[I.T.S.부문] 역사상법에 의한 지능형 자율주행 차량의 제어기 개발

우덕현(Durk-Hyun Wuh),연규봉(Kyu-Bong Yeon),이재천(Jae-Cheon Lee) 한국자동차공학회 2001 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2001 No.11_1

The autonomous intelligent cruise control system has been designed and tested. In this paper only one car following has been tested. Autonomous intelligent cruise control system maintains both the speed and the desired distance to the preceding vehicle using constant headway policy, which means that a steady state vehicle spacing is given by the desired headway times vehicle speed. The headway control system has been designed based upon PID control and PID gains are obtained as a function of the headway. In calculating the throttle angle and braking force, an inverse mapping technique is used. Experimental and simulation results were acceptable and driving feel was good

A Study on the Dynamic Analysis and Control Algorithm for a Motor Driven Power Steering System

Yun, Seokchan,Han, Changsoo,Wuh, Durkhyun The Korean Society of Mechanical Engineers 2002 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.16 No.2

The power steering system for vehicles is becoming essential for supporting the steering efforts of the drivers, especially for the parking lot maneuver Although hydraulic power steering has been widely used for years, its efficiency is not high enough. The problems associated with a hydraulic howe. steering system can be solved by a motor driven power steering (MDPS) system. In this study, a dynamic model and a control algorithm for the ball screw type of MDPS system have been derived and analyzed by using the method of discrete modeling technology. To improve steering feel and power steering characteristics, two derivative gains are added to the conventional power boosting control algorithm. Through simulations, the effects of the control gain on the steering angle gain were verified in the frequency domain. The steering returnability and steering torque phase lag in on-center handling test were also evaluated in the time domain.

Clinical Spectrum and Short-term Effects of Enzyme Replacement Therapy for Mucopolysaccharidosis Type II

전종근,휴우리앙,Cheon, Chong Kun,Hwu, Wuh-Liang The Korean Society of Inherited Metabolic Disease 2018 대한유전성대사질환학회지 Vol.18 No.3

목적: 5명의 제2형 뮤코다당증 환자들의 임상적 스펙트럼과 효소대치요법의 단기간 치료 효과에 관해 알아 보고하고자 하였다. 방법: 5명의 환자들은 임상적 소견, 효소활성화 및 유전자검사에 의해 제2형 뮤코다당증으로 진단되었다. 이두설파제는 일주일 간격으로 0.5 mg/kg의 용량으로 정맥주사 주입을 하였으며, 효소대치요법 시작 전 후 12개월 이상 전신평가를 하였으며, 의무기록을 후향적으로 분석하였다. 결과: 3명의 환자들은 경증 유형, 2명의 환자들은 중증 유형의 제2형 뮤코다당증으로 진단되었다. 진단 시 중위연령은 9.6세(범위 3.4-26세)였다. 네 가계 중 다섯 명의 환자에서 4개의 서로 다른 유전자변이가 확인되었으며, 이중 두 개의 변이는 새로운 돌연변이였다(1개의 작은 삽입돌연변이: p.Thr409Hisfs*22, 1개의 과오돌연변이: p.Gly134Glu). 이중 동일한 유전자돌연변이를 지닌 두 명의 중중 유형의 형제 환자들은 서로 다른 임상적 특징들을 보였다. 12개월 간의 효소대치요법 후 소변 글리코사미노글리칸 배출은 유의하게 감소하였다(P=0.043). 간 및 비장의 용적은 모든 환자에서 유의하게 감소하였다(각각 P=0.043, P=0.043). 이외에도 좌심실질량지수(P=0.042), 어깨관절굽힘각도(P=0.043), 어깨관절벌림각도(P=0.039), 무릎관절굽힘각도(P=0.043), 팔꿉관절굽힘각도(P=0.042), 호흡장애지수(P=0.041)가 모두 호전된 소견을 보였다. 결론: 한국인 제2형 뮤코다당증 환자들은 임상적으로 다양한 특징을 보이며, 단기간의 이두설파제 치료는 주사주입관련 이상반응 없이 심장크기, 호흡장애지수를 포함한 여러 임상적 지표들의 호전에 효과적이었다. Purpose: We aimed to delineate clinical spectrum and short-term effects after enzyme replacement therapy (ERT) for 5 mucopolysaccharidosis type II (MPS II). Methods: Five patients were diagnosed with MPS II by clinical findings, enzyme activity, and genetic testing. Idursulfase was administered by intravenous infusion at a dose of 0.5 mg/kg every week. Observational chart analysis of patients, who underwent systematic investigations more than 12 months after initiation of ERT was done retrospectively. Results: Three patients were classified as having the attenuated type, and 2 patients were classified as having the severe type. The median age at the diagnosis was 9.6 years (range 3.4-26 years). Four different mutations in 5 Korean patients (4 families) with MPS II were identified, among which two were novel mutations (1 small insertion mutation: p.Thr409Hisfs*22, and 1 missense mutation: p.Gly134Glu). Two severe type sibling patients with the same mutation had different clinical manifestation. Urinary glycosaminoglycan excretion decreased within the twelve months of ERT (P=0.043). Liver and spleen volumes showed reductions that were maintained in all patients (P=0.043 and P=0.043, respectively). Improvements were also noted in left ventricular mass index (P=0.042), shoulder flexion (P=0.043), shoulder abduction (P=0.039), knee flexion (P=0.043), elbow flexion (P=0.042), and respiratory distress index (P=0.041). Conclusion: This study demonstrates that Korean patients with MPS II are clinically heterogeneous and indicates that idursulfase is relatively effective in several clinical parameters including heart size and respiratory distress index without infusion-related reactions in patients with MPS II.

RowAMD Distance: A Novel 2DPCA-Based Distance Computation with Texture-Based Technique for Face Recognition

( Waled Hussein Al-arashi ),( Chai Wuh Shing ),( Shahrel Azmin Suandi ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.11

Although two-dimensional principal component analysis (2DPCA) has been shown to be successful in face recognition system, it is still very sensitive to illumination variations. To reduce the effect of these variations, texture-based techniques are used due to their robustness to these variations. In this paper, we explore several texture-based techniques and determine the most appropriate one to be used with 2DPCA-based techniques for face recognition. We also propose a new distance metric computation in 2DPCA called Row Assembled Matrix Distance (RowAMD). Experiments on Yale Face Database, Extended Yale Face Database B, AR Database and LFW Database reveal that the proposed RowAMD distance computation method outperforms other conventional distance metrics when Local Line Binary Pattern (LLBP) and Multi-scale Block Local Binary Pattern (MB-LBP) are used for face authentication and face identification, respectively. In addition to this, the results also demonstrate the robustness of the proposed RowAMD with several texture-based techniques.

지능형 차량 안전 시스템의 개발

김주곤(JooGon Kim),이혜림(Hyerim Lee),정대종(DaeJong Jeong),우덕현(DurkHyeun Wuh) 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11

A new Intelligent Vehicle Safety System(IVSS) which can be used for total safety in the future are proposed in this paper. The proposed IVSS can be applied in the sideslip control of the vehicle safety system with the value of Beta (Beta is a sideslip in the COG of a vehicle) which is obtained from a vehicle observer. The ECU of IVSS is a new electronic integrated chassis controller with 6-axis sensor. It is used for a sensor controller for the sake of vehicle stability. We obtained both a vehicle observer using 6- axis Gyro sensor and Beta through the vehicle observer. To show the feasible performance of the proposed ECU, vehicle observer and Beta, the vehicle tests of the developed value of Beta and the developing value of Beta were accomplished. And results have the better performance comparing to the previous one. From this research, we have obtained core technologies to develop both the ECU of IVSS and the algorithm of vehicle observer including Beta which can be applied to the advanced vehicles such as hybrid vehicles, fuel cell vehicles, and electrical vehicles.

직교배열표를 이용한 에너지흡수 조향계의 해석 및 설계

임재문(Jae Moon Lim),한선규(Sunkyu Han),전원기(Wongi Jeon),우덕현(Durkhyun Wuh),박경진(Gyung-Jin Park) 한국자동차공학회 1999 한국 자동차공학회논문집 Vol.7 No.6

A Study on the Dynamic Analysis and Control Algorithm for a Motor Driven Power Steering System

Seok Chan Yun,Chang Soo Han,Durk Hyun Wuh 대한기계학회 2002 KSME International Journal Vol.16 No.2