Development of Smart Driving System Using iPod and Its Performance Evaluation for People with Severe Physical Disabilities in the Driving Simulator

Woochul Jung,Yongchul Kim 대한인간공학회 2012 大韓人間工學會誌 Vol.31 No.5

Objective: The aim of this study was to develop the adaptive device for severe physical disabilities using smart device in the driving simulator and its performance evaluation. Development of appropriate driving adaptive device for the people with serious physical limitation could contribute to maintain their community mobility. Background: There is lack of adaptive driving devices for the people with disabilities in Korea. However, if smart device systems like iPod and iPhone are used for driving a car, the people with serious physical limitations can improve their community mobility. Method: Both gyroscope and accelerometer from iPod were used to measure the tilted angle of the smart device for driving. Customized Labview program was also used to control three axis motors for steering wheel, accelerator and brake pedals. Thirteen subjects were involved in the experiment for performance evaluation of smart device in simulator. Five subjects had driver licenses. Another four subjects did not have driver licenses. Others were people with disabilities. Results: Average driving score of the normal group with driver license in the simulator increased 46.6% compared with the normal group without driver license and increased 30.4% compared with the disabled group(p<0.01). There was no significant difference in the average driving score between normal group without driver license and disabled group(p>0.05). Conclusion: The normal group with driver license showed significantly higher driving score than other groups. The normal group without driver license and disabled group could improve their driving skills with training in simulator. Application: If follow-up studies would be continued and applied in adapted vehicle for on road environment, many people with more severe disabilities could drive and improve the quality of life.

Investigation of nanoporous platinum thin films fabricated by reactive sputtering: Application as micro-SOFC electrode

Jung, WooChul,Kim, Jae Jin,Tuller, Harry L. Elsevier 2015 Journal of Power Sources Vol.275 No.-

<P><B>Abstract</B></P> <P>Highly porous Pt thin films, with nano-scale porosity, were fabricated by reactive sputtering. The strategy involved deposition of thin film PtO<SUB>x</SUB> at room temperature, followed by the subsequent decomposition of the oxide by rapid heat treatment. The resulting films exhibited percolating Pt networks infiltrated with interconnected nanosized pores, critical for superior solid oxide fuel cell cathode performance. This approach is particularly attractive for micro-fabricated solid oxide fuel cells, since it enables fabrication of the entire cell stack (anode/electrolyte/cathode) within the sputtering chamber, without breaking vacuum. In this work, the morphological, crystallographic and chemical properties of the porous electrode were systematically varied by control of deposition conditions. Oxygen reduction reaction kinetics were investigated by means of electrochemical impedance spectroscopy, demonstrating the critical role of nano-pores in achieving satisfactory micro-SOFC cathode performance.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Porous Pt thin film structure prepared by reactive sputtering. </LI> <LI> Decomposition of PtO<SUB>x</SUB> and oxygen gas evolution play a controlling role. </LI> <LI> Method compatible with micro-fabrication processing. </LI> <LI> Resulting porous Pt thin films show superior performance as SOFC cathodes. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Robust nanostructures with exceptionally high electrochemical reaction activity for high temperature fuel cell electrodes

Jung, WooChul,Gu, Kevin L.,Choi, Yoonseok,Haile, Sossina M. The Royal Society of Chemistry 2014 Energy & environmental science Vol.7 No.5

<P>Metal nanoparticles are of significant importance for chemical and electrochemical transformations due to their high surface-to-volume ratio and possible unique catalytic properties. However, the poor thermal stability of nano-sized particles typically limits their use to low temperature conditions (<500 °C). Furthermore, for electrocatalytic applications they must be placed in simultaneous contact with percolating ionic and electronic current transport pathways. These factors have limited the application of nanoscale metal catalysts (diameter <5 nm) in solid oxide fuel cell (SOFC) electrodes. Here we overcome these challenges of thermal stability and microstructural design by stabilizing metal nanoparticles on a scaffold of Sm<SUB>0.2</SUB>Ce<SUB>0.8</SUB>O<SUB>2−<I>δ</I></SUB> (SDC) films with highly porous and vertically-oriented morphology, where the oxide serves as a support, as a mixed conducting transport layer for fuel electro-oxidation reactions, and as an inherently active partner in catalysis. The SDC films are grown on single crystal YSZ electrolyte substrates by means of pulsed-laser deposition, and the metals (11 μg cm<SUP>−2</SUP> of Pt, Ni, Co, or Pd) are subsequently applied by D.C. sputtering. The resulting structures are examined by TEM, SIMS, and electron diffraction, and metal nanoparticles are found to be stabilized on the porous SDC structure even after exposure to 650 °C under humidified H<SUB>2</SUB> for 100 h. A.C. impedance spectroscopy of the metal-decorated porous SDC films reveals exceptionally high electrochemical reaction activity toward hydrogen electro-oxidation, as well as, in the particular case of Pt, coking resistance when CH<SUB>4</SUB> is supplied as the fuel. The implications of these results for scalable and high performance thin-film-based SOFCs at reduced operating temperature are discussed.</P> <P>Graphic Abstract</P><P>Combination of nanostructured ceria and nanoscale metal particles leads to unprecedented activity for hydrogen and methane electro-oxidation along with excellent morphological stability. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c3ee43546f'> </P>

시뮬링크를 활용한 차량 종 · 횡방향 비선형 모델 예측 제어 성능 평가

정우철(Woochul Jung),강연식(Yeonsik Kang) 한국자동차공학회 2021 한국자동차공학회 부문종합 학술대회 Vol.2021 No.6

본 논문은 Matlab과 Simulink를 활용한 자율주행 차량의 실시간 비선형 모델 예측 제어 알고리즘을 제안한다. AI를 활용한 자율주행 인지 판단 기술이 발달함에 따라 차량의 안정적인 종횡방향 제어 알고리즘도 매우 중요해 졌다. 기존의 차량제어 알고리즘으로는 The DARPA Grand Challenge에서 MIT 대학이 사용한 Pure pursuit 알고리즘과 Stanford 대학이 사용한 Stanley 기법이 널리 활용되었다. 기존의 알고리즘은 횡방향 제어와 종방향 제어가 분리된 횡방향 제어 알고리즘이며 차량의 동역학적 한계를 반영하지 못하는 특징이 있다. 반면 비선형 모델 예측 제어 기법을 사용하면 차량의 동력학적 한계를 반영할 수 있을 뿐만 아니라 동역학 기반 차량 모델을 기반으로 종횡방향 통합 제어가 가능하다. 또한 종횡방향 가속도에 제한을 두어 승차감 측면을 고려한 제어도 가능하다는 장점이 있다. Lane Keeping Assist System (LKAS)의 국제표준인 ISO11270에 따르면 차량의 횡방향 가속도는 3.0m/s^2을 넘지 않을 것을 권장하고 있으며 횡방향 jerk는 0.5초 이동 평균으로 0.5m/s^3을 넘지 않을 것을 권장하고 있다. 본 논문에서는 Simulink를 활용한 시뮬레이션을 통해 모델 예측 제어기에 횡뱡향 가속도 제한조건을 3.0m/s^2로 제한하여 경로 추종 실험을 수행하고 결과를 기존의 pure pursuit 알고리즘과 비교 분석하였다. 실험에 사용된 차량의 시뮬레이션 모델은 Figure 1의 파라메터를 갖는 실험 차량의 Bicycle 모델이며 제어 입력은 조향각과 가속도이다. 비선형 모델 예측 제어 알고리즘의 예측 모델은 챠량의 휠베이스가 반영된 Kinematic 모델이며 전역좌표 X, Y와 속도, Heading이 모델의 State로 반영된다. 또한 Bicycle model의 횡가속도를 가격함수에 포함 시켜 원하는 범위 내에서 제어가 가능하도록 구성하였다. 실험 결과 실시간 비선형 모델 예측 제어 기법을 활용하면 원하는 횡가속도 범위 내에서 주어진 경로를 안정적으로 추종하는 종횡방향 통합 제어기를 구현할 수 있었다.

무등산응회암 내 사장석의 누대구조에 대한 광물학적 예비연구

정우철(Woochul Jung),길영우(Youngwoo Kil),설정환(Junghwan Seol),Nguyen The Cong,최재광(Jaegwang Choi),허민(Min Huh) 대한지질학회 2015 대한지질학회 학술대회 Vol.2015 No.10

생체 모방 종이 작동기의 면내 변형에 관한 연구

정우철(Woochul Jung),김재환(Jaehwan Kim),이선곤(Sunkon Lee),배성훈(Seunghun Bae) 한국소음진동공학회 2005 한국소음진동공학회 학술대회논문집 Vol.2005 No.11

표면 안정화를 통한 고내구성 고체산화물연료전지 전극 개발

정우철(WooChul Jung),구본재(Bonjae Koo),권형욱(Hyunguk Kwon),한정우(Jeong Woo Han) 한국가스학회 2017 한국가스학회 학술대회논문집 Vol.2017 No.11

천왕봉과 안양산을 중심으로 한 무등산응회암의 암석학적 연구

정우철(Woochul Jung),길영우(Youngwoo Ki),허민(Min Huh) 한국암석학회 2014 암석학회지 Vol.23 No.4

중생대 능주분지 내 형성된 무등산응회암은 기존에 여러 암석으로 명명되었으나, 무등산응회암 내 용결구조, 피아메, 암편, 기질의 탈유리화 등을 고려할 때, 무등산응회암이라는 통일된 명칭을 사용하는 것이 바람직하다. 천왕봉 지역과 안양산 지역 무등산응회암은 야외에서 경계가 뚜렷하지 않지만, 암석화학 및 광물화학적 특징과 연대측정 결과에 의해 천왕봉과 안양산 지역 무등산응회암으로 대분된다. 두 지역 무등산응회암은 섭입대 환경의 동원마그마에서 기원한 칼크-알카리 계열의 데사이트질 용결응회암이며, 결정질 응회암이다. 천왕봉 지역 무등산응회암은 안양산 지역 무등산응회암을 형성한 마그마에서 주로 사장석 정출에 의해 형성되었다. Even though Mesozoic Mudeungsan tuff, located within Neungju Basin, has been named several rock names, it should be named as Mudeungsan tuff due to several evidences, such as fiamme, welded texture and rock fragments in the Mudeungsan tuff. Volcanic eruption boundary between the Cheonwangbong and Anyangsan areas is not clear, but petrochemical and mineral chemical evidences with different ages indicate clear petrological boundary between Cheonwangbong and Anyangsan. The Mudeungsan tuffs from Cheonwangbong and Anyangsan is welded crystal tuff with dacitic composition and were generated from cogenetic calc-alkaline magma in the volcanic arc environment. Geochemical events indicate that magma beneath Cheonwangbong was seems to have been evolved from the magma beneath Anyangsan due to fractional crystallization dominated by plagioclase.

고도 변화에 따른 무등산응회암의 암상변화에 대한 예비연구

정우철(Woochul Jung),길영우(Youngwoo Kil),설정환(Junghwan Seol) 대한지질학회 2013 대한지질학회 학술대회 Vol.2013 No.10

High-Pressure Solvent Vapor Annealing with a Benign Solvent To Rapidly Enhance the Performance of Organic Photovoltaics

Jung, Buyoung,Kim, Kangmin,Eom, Yoomin,Kim, Woochul American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.24

<P>A high-pressure solvent vapor annealing (HPSVA) treatment is suggested as an annealing process to rapidly achieve high-performance organic photovoltaics (OPVs); this process can be compatible with roll-to-roll processing methods and uses a benign solvent: acetone. Solvent vapor annealing can produce an advantageous vertical distribution in the active layer; however, conventional solvent vapor annealing is also time-consuming. To shorten the annealing time, high-pressure solvent vapor is exposed on the active layer of OPVs. Acetone is a nonsolvent for poly(3-hexylthiophene-2,5-diyl) (P3HT), but it can dissolve small amounts of 1-(3-methoxycarbonyl)-propyl-1,1-phenyl-(6,6)C<SUB>61</SUB> (PCBM). Acetone vapor molecules can penetrate into the active layer under high vapor pressure conditions to alter the morphology. HPSVA induces a PCBM-rich phase near the cathode and facilitates the transport of free charge carriers to the electrode. Although P3HT is not soluble in acetone, locally rearranged P3HT crystallites are generated. The performance of OPV films was enhanced after HPSVA; the film treated at 30 kPa for 10 s showed optimum performance. Additionally, this HPSVA method could be adapted for mass production because the temporary exposure of films to high-pressure acetone vapor in ambient conditions also improved performance.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2015/aamick.2015.7.issue-24/acsami.5b01658/production/images/medium/am-2015-01658t_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am5b01658'>ACS Electronic Supporting Info</A></P>