HARDWARE IN THE LOOP SIMULATION OF HYBRID VEHICLE FOR OPTIMAL ENGINE OPERATION BY CVT RATIO CONTROL

Yeo, H.,Song, C.H.,Kim, C.S.,Kim, H.S. The Korean Society of Automotive Engineers 2004 International journal of automotive technology Vol.5 No.3

Response characteristics of the CVT system for a parallel hybrid electric vehicle (HEV) are investigated. From the experiment, CVT ratio control algorithm for the optimal engine operation is obtained. To investigate the effect of the CVT system dynamic characteristics on the HEV performance, a hardware in the loop simulation (HILS) is performed. In the HILS, hardwares of the CVT belt-pulley and hydraulic control valves are used. It is found that the engine performance by the open loop CVT ratio control shows some deviation from the OOL in spite of the RCVs open loop control ability. To improve the engine performance, a closed loop control of the CVT ratio is proposed with variable control gains depending on the shift direction and the CVT speed ratio range by considering the nonlinear characteristics of the RCV and CVT belt-pulley dynamics. The HILS results show that the engine performance is improved by the closed loop control showing the operation trajectory close to the OOL.

Regenerative braking algorithm for a hybrid electric vehicle with CVT ratio control

Yeo, H.,Hwang, S.,Kim, H. MECHANICAL ENGINEERING PUBLICATIONS LTD 2006 Proceedings of the Institution of Mechanical Engin Vol.220 No.11

Defect structure and Fermi-level pinning of BaTiO₃ co-doped with a variable-valence acceptor (Mn) and a fixed-valence donor (Y)

Yeoh, Yun-Young,Jang, Hyejin,Yoo, Han-Ill The Royal Society of Chemistry 2012 Physical chemistry chemical physics Vol.14 No.5

<P>Defect structures of BaTiO<SUB>3</SUB> and the like co-doped with variable-valence acceptors and donors are not clear particularly in transition from acceptor domination to donor domination with increasing oxygen activity. We have, thus, examined the electrical conductivity and thermoelectric power of BaTiO<SUB>3</SUB> co-doped with a variable-valence acceptor <IMG SRC='http://www.rsc.org/ej/CP/2012/c2cp22711h/c2cp22711h-t1.gif'> and a fixed-valence donor <IMG SRC='http://www.rsc.org/ej/CP/2012/c2cp22711h/c2cp22711h-t2.gif'> in different co-doping ratios (<I>m</I><SUB>d</SUB>/<I>m</I><SUB>a</SUB>) as functions of oxygen activity in the range of −20 < log <I>a</I><SUB>O<SUB>2</SUB></SUB>≤ 0 at elevated temperatures of 900–1100 °C. Their systematic variations with <I>m</I><SUB>d</SUB>/<I>m</I><SUB>a</SUB> and log <I>a</I><SUB>O<SUB>2</SUB></SUB> are reported, and thereby defect structures of the co-doped BaTiO<SUB>3</SUB> depending on <I>m</I><SUB>d</SUB>/<I>m</I><SUB>a</SUB> are determined. It is found that for the co-doping ratio 1 < <I>m</I><SUB>d</SUB>/<I>m</I><SUB>a</SUB> < 2, the Fermi level is pinned at a few <I>kT</I>'s around the deep level of <IMG SRC='http://www.rsc.org/ej/CP/2012/c2cp22711h/c2cp22711h-t3.gif'> across the otherwise p-type semiconducting log <I>a</I><SUB>O<SUB>2</SUB></SUB>-region of Mn-singly doped BaTiO<SUB>3</SUB>, and attributed to deep acceptor–shallow donor mutual compensation <IMG SRC='http://www.rsc.org/ej/CP/2012/c2cp22711h/c2cp22711h-t4.gif'>, thus turning otherwise p-type semiconducting BaTiO<SUB>3</SUB> semi-insulating.</P> <P>Graphic Abstract</P><P>The Fermi level of BaTiO<SUB>3</SUB> is pinned by co-doping a fixed-valence donor (Y) and a variable valence acceptor (Mn) in the ratio <I>m</I><SUB>d</SUB>/<I>m</I><SUB>a</SUB> = 1.8 due to their mutual compensation. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2cp22711h'> </P>

Effect of Substrate Bias on the Tribological Behavior of ta-C Coating Prepared by Filtered Cathodic Vacuum Arc

Yeoh Chin Ean,장영준,김종국,Willey Liew Yun Hsien,Nancy Julius Siambun,김석삼 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.5

Tetrahedral amorphous carbon (ta-C) films were coated on the tungsten carbide cobalt by using filter cathodic vacuum arc (FCVA). All the specimens were coated at different bias voltage, such as 0 V, 40 V, 80 V, 120 V, and 160 V. The tribological behavior of all these specimens were evaluated by using a ball-on-disc type of tribo-test. Raman analysis was used in this research for investigating the bond structure in the coating films. From the experiment result shown the variation of the bias voltage of the ta-C coating do not bought to the change of the mechanical properties. As well as for the tribological aspect. Whereas, it only bought to the influence of the wear properties. The lowest wear rate result were found from the ta-C film that coated under 40V. This was due to the surface contact area and the surface roughness properties different at the different bias voltage.

A 1.3-GHz 350-mW Hybrid Direct Digital Frequency Synthesizer in 90-nm CMOS

Yeoh, Hong Chang,Jung, Jae-Hun,Jung, Yun-Hwan,Baek, Kwang-Hyun IEEE 2010 IEEE journal of solid-state circuits Vol.45 No.9

<P>This paper presents a low-power direct digital frequency synthesizer (DDFS) based on a hybrid design with a maximum operating frequency of 1.3 GHz. The proposed hybrid design is capable of extending the resolution of traditional nonlinear digital-to-analog converter (DAC)-based DDFS by adding a linear slope component to the approximated sine wave produced from a nonlinear DAC via an additional linear DAC. With an 11-bit combined DAC, the prototype DDFS produces a minimum spurious free dynamic range (SFDR) of 52 dBc from dc up to Nyquist frequency when clocked at 1.3 GHz. This 90-nm CMOS chip occupies 2 <TEX>${\hbox {mm}}^{2}$</TEX> including bond pads and dissipates 350 mW with a 1.2-V digital supply and 2.5-V analog supply. The FOM of this chip is measured at 1207.9 <TEX>$\hbox{GHz} \cdot 2 ^{\rm ENOB} /\hbox{W}$</TEX> .</P>

Identity and Network of Chinese Diaspora in Southeast Asia with Special Reference to a Malaysian Case of Communal Economic Movement

Yeoh, Kok Kheng(여콩콩) 전남대학교 글로벌디아스포라연구소 2012 전남대학교 세계한상문화연구단 국제학술회의 Vol.2012 No.5

동남아시아에서 중국인의 편재는 상당히 독특한 현상이다. 그럼에도 불구하고 동남아시아로의 중국인의 대규모 인구통계적 이동은 현대적인 현상이다. 중국인의 해외 이주에도 많은 유출요인이 있겠지만, 목록의 상위를 차지하는 것은 19세기 중반 이후 중국에 닥친 재난이었다. 절박함으로 인해 굶주린 소작농들, 가난한 노동자들, 성공하지 못한 상인들, 지식인들의 물결은 더 나은 환경을 찾기 위해 동남아시아의 서구 식민지로 몰려 들었다. 2차 세계대전이 종결되고 식민지들이 독립된 이후, 동남 아시아의 대부분 중국인들은 그들이 거주하고 있던 새로운 나라의 시민이 되었다. 오늘날 말레이시아 화교의 경우를 보면, 대부분은 거의 잘 알려져 있는 직업에 종사하고 있다. 따라서 20세기 초반 다른 동남아시아 국가들의 화교 사회와는 대조적으로 말레이시아 화교 사회가 특히 많은 노동자와 소작농 계급으로 구성되었다는 것을 상상하기는 쉬운 일이 아니다. 화교 사회의 힘과 성공에도 불구하고 말레이시아에서 한국과 일본의 유명한 금융재벌 식의 현대적인 화교 비즈니스 문화는 결코 생겨날 수 없다. 말레이시아 화교 가정의 1/3에 달하는50만명 이상의 노동계급 화교가 손해를 보고 일부 사람들은 전 재산을 잃게 되었던 전례가 없는 큰 실패로 끝난 1980년대의 "민영화 운동" 또는 문자 그대로 "대기업 운동"은 전통적인 화교 비즈니스의 기저를 이루고 있는 화교 커뮤니티의 근본적인 나약함의 자각을 반영하고 있다. 이 논문은 그 비극적인 사건을 재검토하고, 큰 실패의 주요 요인을 조사하고, 불행하게 끝난 운동을 후원했던 공동 조직의 정체성을 면밀히 살려 본다. 그리고 전통적 길드와 협회의 복잡한 상황 속에 집단 사고방식고 "방(bang)" 정신에 의해 양식화된 초기 이주자 사회의 고된 발전과정에서 깊게 뿌리내린 말레이시아 화교 커뮤니티의 준자본조의 경제구조의 배경에 맞선 민족적 부흥운동으로서의 민영화의 역할을 분석한다. The omnipresence of the Chinese in Southeast Asia is a rather unique phenomenon. The large-scale demographic movement of the Chinese into Southeast Asia is, nevertheless, a modern phenomenon. The "push" factors in the Chinese migration overseas were numerous but topping the list were the calamities that befell China since the mid-nineteenth century. Waves and waves of hungry peasants, poor workers, frustrated merchants and intellectuals were pushed by deseration overseas, many to the Western colonies in Southeast Asia, to look for greener pastures. After these colonies attained independence after the Second World War, most Chinese to Southeast Asia became citizens of the new countries where they resided. Take the case of Malaysia. Today, the Malaysian Chinese are employed in nearly all known occupations in the country. Hence, it is difficult to imagine now that in the early period of the last century, in contrast with the Chinese societies in the other Southeast Asia countries (or world-be countries), it was a peculiar characteristic of the Malayan Chinese society that it considered of partifularly large working and peasant classes. For all its reputed strength and success, even the modern Chinese business culture in Malaysia has never been able to produce anything like famed financial conglomerateds of South Korea (chaebol) and Japan (zaibatsu). The "corporatization movement" (daqiye yundong), or literally the "big enterprise movement", of the 1980s reflected the Chinese community"s realization of the fundamental weaknesses underlying traditional Chinese business management, which unfortunately ended in a fiasco that was unprecedented in Malaysia, in which more than half a million mostly working-class Chinese-perhaps one in three Chinese households-lost their money, and in some cases, their entire life savings. This paper reviews the unfolding of the tragedy, examines the major factors behind the debacle, scrutinizes the identity of the communal organizations that sponsored the ill-fated movement, and anlayzed the role of corporatization as an ethnic revival movement against the backdrop of the Malaysian Chinese community"s semi-capotalistic economic structure, which is deeply rooted in the arduous process of development of the early migrant society, stylized by clan mentality and bang spirit amidst a complex web of traditional guilds and associations.

Deep Learning Algorithm for Simultaneous Noise Reduction and Edge Sharpening in Low-Dose CT Images: A Pilot Study Using Lumbar Spine CT

Yeoh Hyunjung,Hong Sung Hwan,Ahn Chulkyun,Choi Ja-Young,Chae Hee-Dong,Yoo Hye Jin,Kim Jong Hyo 대한영상의학회 2021 Korean Journal of Radiology Vol.22 No.11

Objective: The purpose of this study was to assess whether a deep learning (DL) algorithm could enable simultaneous noise reduction and edge sharpening in low-dose lumbar spine CT. Materials and Methods: This retrospective study included 52 patients (26 male and 26 female; median age, 60.5 years) who had undergone CT-guided lumbar bone biopsy between October 2015 and April 2020. Initial 100-mAs survey images and 50-mAs intraprocedural images were reconstructed by filtered back projection. Denoising was performed using a vendor-agnostic DL model (ClariCT.AITM, ClariPI) for the 50-mAS images, and the 50-mAs, denoised 50-mAs, and 100-mAs CT images were compared. Noise, signal-to-noise ratio (SNR), and edge rise distance (ERD) for image sharpness were measured. The data were summarized as the mean ± standard deviation for these parameters. Two musculoskeletal radiologists assessed the visibility of the normal anatomical structures. Results: Noise was lower in the denoised 50-mAs images (36.38 ± 7.03 Hounsfield unit [HU]) than the 50-mAs (93.33 ± 25.36 HU) and 100-mAs (63.33 ± 16.09 HU) images (p < 0.001). The SNRs for the images in descending order were as follows: denoised 50-mAs (1.46 ± 0.54), 100-mAs (0.99 ± 0.34), and 50-mAs (0.58 ± 0.18) images (p < 0.001). The denoised 50-mAs images had better edge sharpness than the 100-mAs images at the vertebral body (ERD; 0.94 ± 0.2 mm vs. 1.05 ± 0.24 mm, p = 0.036) and the psoas (ERD; 0.42 ± 0.09 mm vs. 0.50 ± 0.12 mm, p = 0.002). The denoised 50-mAs images significantly improved the visualization of the normal anatomical structures (p < 0.001). Conclusion: DL-based reconstruction may enable simultaneous noise reduction and improvement in image quality with the preservation of edge sharpness on low-dose lumbar spine CT. Investigations on further radiation dose reduction and the clinical applicability of this technique are warranted.

Re-examination of Opisthorchis viverrini Infection in Northeast Thailand

Yeoh, Kheng-Wei,Promthet, Supannee,Sithithaworn, Paiboon,Kamsaard, Supot,Parkin, Donald Maxwell Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.8

Background: Liver fluke infection caused by the parasite Opisthorchis viverrini (O. viverrini), a human carcinogen, is endemic in north-eastern Thailand and remains a major health problem. Objectives: The objectives of the study were to (1) resurvey the prevalence of O. viverrini infection in a field site from the Khon Kaen Cohort Study (in newly recruited subjects as well as previous cohort subjects surveyed in 1992); (2) investigate how subjects' lifestyle habits and their exposure to health promotion initiatives influence changes in prevalence of O. viverrini infection. Materials and Methods: The prevalence of O. viverrini infection in the cohort subjects (as well as new subjects) was investigated using faecal egg counts. Information on demographic factors, lifestyle and awareness of health promotion initiatives were obtained through questionnaires. Results: O. viverrini infection rates in the same individuals of the cohort were lower in 2006 than in 1992. Also, by studying the period effect, the current 35-44 year olds had a 12.4% (95% CI 3.9% to 20.9%) lower prevalence of O. viverrini infection than the 35-44 year olds in 1992 (24.2% versus 11.8%). Lifestyle choices showed that smoking and alcohol consumption were associated with an increased chance of acquiring O. viverrini infection with adjusted odds ratios of 10.1 (95%CI 2.4-41.6) and 5.3 (95%CI 1.2-23.0), respectively. Conclusions: Our study has demonstrated that although the prevalence of O. viverrini infection over a 14-year period has decreased, unhealthy lifestyle was common with smoking and alcohol consumption being associated with increased chances of infection, emphasising the double burden of disease which developing countries are facing.

Surgical Options for Ipsilateral Breast Tumor Recurrence: Mastectomy Versus Repeat Breast-Conserving Surgery

Hyunsu Yeoh,Jong-Ho Cheun,Han-Byoel Lee,Wonshik Han,Hong-Kyu Kim 한국유방암학회 2022 Journal of Breast Disease Vol.10 No.1

Purpose: The standard care for patients with ipsilateral breast tumor recurrence (IBTR) after breast-conserving surgery (BCS) is a total mastectomy (TM); however, there is growing interest in repeating BCS for IBTR. Methods: We retrospectively analyzed patients with IBTR who underwent initial BCS for breast cancer at our institution between January 2000 and December 2018. The Kaplan-Meier method was used to compare survival rates between the standard BCS-TM treatment group and the repeat-BCS group. Results: We enrolled 209 IBTR patients with a median follow-up of 102.3 months. No significant differences were observed in overall survival (10 years: 87.3% vs. 78.8%; hazard ratio [HR], 1.11; 95% confidence interval [CI], 0.44-2.81; p=0.821), distant metastasis free survival (10 years: 73.9% vs. 77.7%; HR, 0.80; 95% CI, 0.37-1.72; p=0.727) and disease-free survival (10 years: 57.1% vs. 65.2%; HR, 0.63; 95% CI, 0.35-1.12; p=0.115) between two groups. Repeat-BCS group showed significantly poorer locoregional recurrence free survival rate than did the TM group (HR, 2.44; 95% CI, 1.06-5.56; p=0.029) but the significance was not shown after excluding ipsilateral breast tumor recurrence events. Conclusion: No significant differences were observed in survival outcomes and recurrence rates between patients with IBTR who underwent mastectomy or repeat BCS regardless of molecular subtype, except secondary IBTR rates.

산학협동을 통한 목제품 디자인 개발에 관한 연구

윤여항(Yeoh Hang Yoon) 한국가구학회 2001 한국가구학회지 Vol.12 No.1

Cultural needs of human have grown enormously. Consumer trend and individual taste have become more individualistic and diversified Efforts to improve the quality of life have changed the concept of life space as well as the concept of interior life supplies. Products are no longer standardized and produced in massive scale, thus a shift of value has risen. Damages done by the economical development have made consumers take interests in products that are more natural and in harmony with human beings. It is a tendency that wooden materials are becoming a preference as a specific alternative.<br/> There is a great social change with a new paradigm like this. Considering the change, we propose a new vision and activation plan on design development of wooden products through specific and practical studies by the system of educational and industrial cooperation which is an organic association system for developing human resources of educational system and producing profits of industry. From it, we can expect great effects as a competitive design of coming future.<br/>