Receding Horizon Passive Control for a Walk-Assist Robot

Chun-Hsu Ko,Kuu-Young Young,Sunil K. Agrawal 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

Passive walk-assist robots play an important role in providing safe mobility to the elderly. They use the brake torques on the wheels to assist the user walking and differentially steer the vehicle, while the user pushes the walker. It is important to appropriately select the brake torques in accordance with user-applied forces for controlling the robot. In this paper, a receding horizon passive control method is presented to calculate the brake torques so that the robot can perform point-to-point guidance. The control scheme first designs a smooth path to be followed by the robot. The terminal-state penalty is added to the cost function for path following, while the end point equality constraint is used to achieve the goal when the robot approaches the end point. The passivity of the system is guaranteed by adding the brake torque constraints into the formulated optimization problem. To be efficient, we look for a suboptimal solution of the optimization problem by using an analytical method. Simulation results show that the passive walk-assist robot, along with the proposed control scheme, can guide the user to a goal effectively.

Foreword of Part 2

Hsu-Chun Yen,Han-Chieh Chao,Whai-En Chen 보안공학연구지원센터 2007 International Journal of Smart Home Vol.1 No.2

Dielectric properties of Mg0.95Ni0.05TiO3 ceramic modified by Nd0.5Na0.5TiO3 at microwave frequencies

Chun-Hsu Shen,Cheng-Liang Huang,Chuan-Feng Shih,Chih-Ming Huang 한국물리학회 2009 Current Applied Physics Vol.9 No.5

The effect of Nd0.5Na0.5TiO3 addition on the microwave dielectric properties of Mg0.95Ni0.05TiO3 ceramics was investigated. The Nd0.5Na0.5TiO3 content plays a significant role in improving the dielectric properties. Microwave dielectric measurements show an increase in the dielectric constant (εr) and temperature coefficient of the resonant frequency (τf) and a decrease in the quality factor (Q × f value) with increasing Nd0.5Na0.5TiO3 content. By properly adjusting the Nd0.5Na0.5TiO3 content, a zero τf value can also be obtained, which make Mg0.95Ni0.05TiO3 a promising material in wireless systems. At 1300 ℃, the 0.81Mg0.95Ni0.05TiO3–0.19Nd0.5Na0.5TiO3 ceramics possess excellent microwave dielectric properties: a dielectric constant (εr) of 25.61, a Q × f value of 69,100 GHz, and a τf value of -6 ppm/℃. The effect of Nd0.5Na0.5TiO3 addition on the microwave dielectric properties of Mg0.95Ni0.05TiO3 ceramics was investigated. The Nd0.5Na0.5TiO3 content plays a significant role in improving the dielectric properties. Microwave dielectric measurements show an increase in the dielectric constant (εr) and temperature coefficient of the resonant frequency (τf) and a decrease in the quality factor (Q × f value) with increasing Nd0.5Na0.5TiO3 content. By properly adjusting the Nd0.5Na0.5TiO3 content, a zero τf value can also be obtained, which make Mg0.95Ni0.05TiO3 a promising material in wireless systems. At 1300 ℃, the 0.81Mg0.95Ni0.05TiO3–0.19Nd0.5Na0.5TiO3 ceramics possess excellent microwave dielectric properties: a dielectric constant (εr) of 25.61, a Q × f value of 69,100 GHz, and a τf value of -6 ppm/℃.

THE AMELIORATING EFFECTS OF BROWN ALGAE EXTRACTS ON DIABETES INDUCED REPRODUCTIVE DAMAGE

Yu-Chun Hsu,Christina Wong,Zwe-Ling Kong 한국수산과학회 양식분과 2015 한국수산과학회 양식분과 학술대회 Vol.2015 No.5

Early Intervention with High-Dose Steroid Pulse Therapy Prolongs Disease-Free Interval of Severe Alopecia Areata: A Retrospective Study

( Chao Chun Yang ),( Chun Te Lee ),( Chao Kai Hsu ),( Yi Pei Lee ),( Tak Wah Wong ),( Sheau Chiou Chao ),( Julia Yu Yun Lee ),( Hamm Ming Sheu ),( Wenchieh Chen ) 대한피부과학회 2013 Annals of Dermatology Vol.25 No.4

Background: Spontaneous recovery of severe alopecia areata is rare and the condition is difficult to treat. Objective: The aim of this study is to investigate and compare the effects and safety of steroid pulse therapy between oral and intravenous administrations between 1999 and 2010 at the Department of Dermatology, National Cheng Kung University Hospital. Methods: Data were retrospectively retrieved. A satisfactory response was defined as more than 75% hair regrowth in the balding area. Results: A total of 85 patients with more than 50% hair loss were identified and treated, with an overall satisfactory response rate of 51.8%. The mean follow-up time was 37.6 months, with a relapse rate of 22.7%. Patients with alopecia areata (hereafter, AA) of recent onset within one year showed higher response rates (p< 0.001) and lower relapse rates compared to patients with AA persisting for more than 1 year. Further, even in patients with alopecia totalis, alopecia universalis or ophiasis type, early treatment resulted in a satisfactory response rate of 47% among the treated patients. In general, oral therapy was as effective and well-tolerated as intravenous therapy. Conclusion: The response rate is determined by disease severity and time of intervention, not by the administration form of steroid pulse therapy. Oral steroid pulse therapy can be considered as the first-line treatment for patients with severe AA of recent onset within one year. (Ann Dermatol 25(4) 471∼474, 2013)

Safety considerations for withdrawal of nucleos(t)ide analogues in patients with chronic hepatitis B: First, do no harm

Yao-Chun Hsu,Cheng-Hao Tseng,Jia-Horng Kao 대한간학회 2023 Clinical and Molecular Hepatology(대한간학회지) Vol.29 No.4

Nucleos(t)ide analogues (NA) are widely used to treat hepatitis B virus (HBV) infection, but they cannot eradicate the virus and treatment duration can be lifelong if the endpoint is set at seroclearance of the hepatitis B surface antigen (HBsAg). As an alternative strategy, finite NA therapy without the prerequisite of HBsAg seroclearance has been proposed to allow treatment cessation in patients with sustained undetectable HBV viremia for two to three years. However, reactivation of viral replication almost always follows NA withdrawal. Whereas HBV reactivation might facilitate HBsAg seroclearance in some, it could lead to serious acute flare-ups in a certain proportion of patients. Occurrence and consequences of NA withdrawal flares are complicated with various factors involving the virus, host, and treatment. Accurate risk prediction for severe flares following NA cessation is essential to ensure patient safety. The risks of life-threatening flares in patients who discontinued NA according to the stopping rules of current guidelines or local reimbursement policies have recently been quantitatively estimated in large-scale studies, which also provided empirical evidence to help identify vulnerable patients at risk of devastating outcomes. Moreover, risk predictors were further explored and validated to hopefully aid in patient selection and management. In this narrative review with a focus on patient safety, we summarize and discuss current literature on the incidence of severe flares following NA cessation, risk stratification for candidate selection, rules of posttreatment monitoring, and indications for treatment resumption. We also share our thoughts on the limitations of existing knowledge and suggestions for future research.

Research on Near Infrared Spectroscopy Application for Aflatoxin Testing on Rice

( I-chun Tung ),( Tsung-hsin Wu ),( Han-chun Hsu ),( Suming Chen ),( Chao-yin Tsai ),( Yung-kun Chuang ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

Rice is one of the most important staple food in the world. In many countries, environments with high temperature/humidity may provide favorable conditions for fungal propagation and production of aflatoxins during rice storage. Aflatoxin B₁ (AFB₁), one of the secondary metabolites produced by Aspergillus flavus and Aspergillus parasiticus, is particularly carcinogenic to humans. People might very likely cause severe illness once rice is contaminated by aflatoxins. Therefore, the objective of this study is to develop a nondestructive method for rapid and accurate detection of the AFB₁ content in rice. In the present study, evaluation of AFB₁ contaminated rice were conducted by using near infrared spectroscopy (NIRS) technique with chemometrics. NIR Spectra and the AFB₁ contents of the artificially contaminated rice samples were measured by FOSS NIRS 6500 spectrometer and LC-MS/MS, respectively. Modified partial least square regression (MPLSR), a commonly used multivariate analysis method was then used to build calibration models. In summary, NIRS associated with chemometrics could provide a useful tool for rapid and accurate detection of AFB₁ content in rice.

Real Experience of Cohort Study

( Yao-chun Hsu ) 대한간학회 2013 임상연구방법론워크숍 Vol.2013 No.1

Development of Phalaenopsis Flowering Quality Prediction Models

( Han-chun Hsu ),( Suming Chen ),( Chao-yin Tsai ),( Yung-huei Chang ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

Phalaenopsis is an important exported flower in Taiwan and its flowering quality was reported to be correlated to its leaves’ carbohydrate contents and external traits. Phalaenopsis Sogo Yukidian 'V3' was used as the experimental samples in this research. A hand-held spectrometer and a hyperspectral system were used to build the carbohydrate content prediction models (CC model) respectively first, and then combined with leaves’ external traits obtained from hyperspectral imaging to build the flowering quality prediction model (FQ model). The advantage and application of FQ models built by both devices were compared. The results showed that the CC models built with MPLSR for glucose, fructose, sucrose, total soluble sugar, starch and total carbohydrates by hyperspectral system were all better than those by hand-held spectrometer. The results of FQ models with PLSDA and SVM also showed that the performance of hyperspectral system to discriminate quality levels was better. As for the ANN models’ results to predict the total number of flowers, the errors using both devices were all lower than 0.87. The research proved that using spectral technique to predict the interior contents in Phalaenopsis leaves or flowering quality were both feasible. Although the performance of hyperspectral imaging system is better than that of hand-held spectrometer, it was expensive and not as convenient as hand-held spectrometer. We can adopt some other ways such as using multispectral imaging system or optimize the performance of hand-held spectrometer if we want to apply the results to the Phalaenopsis industry.

Classifying Endemic Fagaceae Species in Taiwan using Leaf Images

( Hao-chun Hsu ),( Cheng-hao Lee ),( Chih-kai Yang ),( Fang-hua Chu ),( Ming-jer Tsai ),( Yan-fu Kuo ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

Fagaceae is one of the plant family which dominate the broad-leaved forests in Taiwan and have considerable value in economy and ecology. Traditionally, plant species identification based on leaf morphologies and is conducted using naked-eye observation. This study is proposed to distinguish the Fagaceae species using image processing and machine learning. In this study, leaf images of 10 Fagaceae species were collected. A serial of traits relevant to leaf morphologies, such as morphological, color, shape, and venation traits, were quantified from the leaf images. A support vector machine classifier was then developed to identify the species using the quantified traits. The proposed approach reached an identification accuracy of 95.8%.