Microstructures and microwave dielectric properties of La1-xBx(Mg0.5Sn0.5)O3 ceramics

Yih-Chien Chen,Yen-Nien Wang,Wei-Cheng Lee 한국물리학회 2012 Current Applied Physics Vol.12 No.3

The microwave dielectric properties of La1-xBx(Mg0.5Sn0.5)O3 ceramics were examined with a view to their exploitation for mobile communication. The La1-xBx(Mg0.5Sn0.5)O3 ceramics were prepared by the conventional solid-state method with various sintering temperatures. The X-ray diffraction patterns of the La0.995B0.005(Mg0.5Sn0.5)O3 ceramics revealed no significant variation of phase with sintering temperatures. A maximum apparent density of 6.58 g/cm3, a dielectric constant (εr) of 19.8, a quality factor (Q × f) of 41,800 GHz, and a temperature coefficient of resonant frequency (sf) of -86 ppm/℃ were obtained for La0.995B0.005(Mg0.5Sn0.5)O3 ceramics that were sintered at 1500 ℃ for 4 h.

Improving microwave dielectric properties of La2.98/3Sr0.01(Mg0.5Sn0.5)O3 ceramics with CuO additive

Yih-Chien Chen 한국물리학회 2012 Current Applied Physics Vol.12 No.2

The microwave dielectric properties of CuO-doped La2.98/3Sr0.01(Mg0.5Sn0.5)O3 ceramics were investigated with a view to their application in microwave devices. CuO-doped La2.98/3Sr0.01(Mg0.5Sn0.5)O3ceramics were prepared by the conventional solid-state method. The X-ray diffraction patterns of CuOdoped La2.98/3Sr0.01(Mg0.5Sn0.5)O3 ceramics exhibited no significant variation of phase with sintering temperature. By adding 0.75 wt.% CuO, a dielectric constant of 20.07, a quality factor (Q × f) of 63,000 GHz, and a temperature coefficient of resonant frequency sf (-77.0 ppm/℃) were obtained when La2.98/3Sr0.01(Mg0.5Sn0.5)O3 ceramics were sintered at 1500 ℃ for 4 h.

Evaluation of Heat Transfer in Acupuncture Needles: Convection and Conduction Approaches

Ya-Chien Chung,Chieh-Han John Tzou,Tzyy-Yih Yang 사단법인약침학회 2015 Journal of Acupuncture & Meridian Studies Vol.8 No.2

Originating in ancient China, acupuncture using needles has been developed for thousands of years and has received attention for its reported medical remedies, such as pain relief and chronic disease treatment. Heat transfer through the needles, which might have effects on the biomechanism of acupuncture, providing a stimulus and regulating homeostasis, has never been studied. This article analyzes the significance of heat transfer through needles via convection and conduction, approached by means of computational analysis. The needle is a cylindrical body, and an axis symmetrical steady-state heat-transfer model that viscosity and static pressure was not applied. This article evaluates heat transfer via acupuncture needles by using five metal materials: silver, copper, brass, iron, and stainless steel. A silver needle of the type extensively applied in acupuncture can dissipate more than seven times as much heat as a stainless steel needle of the same type. Heat transfer through such a needle is significant, compared to natural body-energy consumption over a range of ambient temperatures. The mechanism by which heat flows in or out of the body through the needles may be crucial in the remedial efficacy of acupuncture.

A New Correlation Equation for Calculating the Frictional Torque of the Nut at Different Feed Velocities and Nut Temperatures

Tzu-Chien Kuo,Yih-Chyun Hwang,Wen-Hsin Hsieh 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.1

Among the errors in precision machining, thermal error has been recognized as the most significant error. The heat of the nut in the feed drive system plays an important role in the thermal error generated by the feed drive system. To better estimate and further understand the increase in temperature and thermal deformation of the ball screw during operation, a new correlation equation for the frictional torque of the nut is proposed and determined in this study for the calculation of the frictional torque of the nut and the heat generated by the nut at different feed velocities and nut temperatures. In this study, a set of devices for measuring the frictional torque of the nut under different feed velocities and different nut temperatures is designed and established. Various experimental conditions are designed to measure the frictional torque of the nut at different feed velocities and different nut temperatures to establish a correlation equation for the frictional torque of the nut. In addition, for further confirmation, the method for measuring the frictional torque of the nut used in this study is compared with the method using a handheld digital force gauge. The correlation equation for the frictional torque of the nut established in this study is based on the LuGre model and the formula of the frictional torque due to the viscosity of the lubricant of the bearing at different temperatures. The results show that the root-mean-square error between the frictional torque of the nut calculated by the correlation equation and that measured experimentally is 0.0301 N-m, indicating that the correlation equation for the frictional torque of the nut proposed in this study is accurate and feasible.

Analytical methodology for solving anisotropic materials of antiplane problems

Ma, Chien-Ching,Cheng, Yih-Hong Techno-Press 1999 Structural Engineering and Mechanics, An Int'l Jou Vol.7 No.2

An analytical methodology for solving antiplane problem of anisotropic materials is proposed and discussed in detail in this study. The material considered in this study possesses a symmetry plane at z=0. The relationship between the problems of anisotropic materials and the corresponding isotropic problems are established by Ma (1996) on the basis of the general solutions for the shear stresses and displacement in both the polar and Cartesian coordinate systems. This implies that any solution of an anisotropic problem can be obtained by solving a corresponding isotropic problem. In this study some examples and numerical results are presented as an explanation of how the complicated anisotropic problem could be solved by the associated simpler isotropic problem.

A Study of Resource Utilization Improvement on Cloud Testing Platform

( Jong-yih Kuo ),( Hui-chi Lin ),( Chien-hung Liu ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.7

This paper developed the software testing factory-cloud testing platform (STF-CTP) to address the software compatible issues in various smart devices. Software developers who only require uploading the application under test (AUT) and test script can test plenty of smart devices in STF-CTP. The challenge for the cloud test platform is how to optimize the resource and increase the performance in the limited resource. This paper proposed a new scheduling mechanism and a new process of the system operation which is based on the OpenStack platform. We decrease about 40% memory usage of OpenStack server, increase 3% to 10% Android device usage of STF-CTP, enhance about 80% test job throughput and reduces about 40% test job average waiting time.

Teaching Switching Converter Design Using Problem-Based Learning with Simulation of Characterization Modeling

Wang, Shun-Chung,Chen, Yih-Chien,Su, Juing-Huei The Korean Institute of Power Electronics 2010 JOURNAL OF POWER ELECTRONICS Vol.10 No.6

In this paper, teaching in a "switching converter (SC) design" course using problem-based learning (PBL) with dynamicbehavior- model simulation, given at Lunghwa University of Science and Technology (LHU), Taiwan, is proposed. The devised methodology encourages students to design and implement the SCs and regulate the controller's parameters in frequency domain by using 'sisitool' ('bode') in the MATLAB toolbox. The environment of PBL with converter characterization modeling and simulation reforms the learning outcome greatly and speeds up the teaching-learning process. To qualify and evaluate the learning achievements, a hands-on project cooperated with the continuous assessment approach is performed to modulate the teaching pace and learning direction in good time. Results from surveys conducted in the end of the course provided valuable opinions and suggestions for assessing and improving the learning effect of the proposed course successively. Positive feedbacks from the examinations, homework, questionnaires, and the answers to the lecturer's quizzes during class indicated that the presented pedagogy supplied more helpfulness to students in comparisons with conventional teaching paradigm, their learning accomplishments were better than expected as well.

Teaching Switching Converter Design Using Problem-Based Learning with Simulation of Characterization Modeling

Shun-Chung Wang,Yih-Chien Chen,Juing-Huei Su 전력전자학회 2010 JOURNAL OF POWER ELECTRONICS Vol.10 No.6

In this paper, teaching in a “switching converter (SC) design” course using problem-based learning (PBL) with dynamicbehavior-model simulation, given at Lunghwa University of Science and Technology (LHU), Taiwan, is proposed. The devised methodology encourages students to design and implement the SCs and regulate the controller’s parameters in frequency domain by using ‘sisitool’ (‘bode’) in the MATLAB toolbox. The environment of PBL with converter characterization modeling and simulation reforms the learning outcome greatly and speeds up the teaching-learning process. To qualify and evaluate the learning achievements, a hands-on project cooperated with the continuous assessment approach is performed to modulate the teaching pace and learning direction in good time. Results from surveys conducted in the end of the course provided valuable opinions and suggestions for assessing and improving the learning effect of the proposed course successively. Positive feedbacks from the examinations, homework, questionnaires, and the answers to the lecturer’s quizzes during class indicated that the presented pedagogy supplied more helpfulness to students in comparisons with conventional teaching paradigm, their learning accomplishments were better than expected as well.

Metallic Stent Placement in Hemodialysis Graft Patients after Insufficient Balloon Dilation

Huei-Lung Liang,Huay-Ben Pan,Yih-Huie Lin,Chiung-Yu Chen,Hsiao-Min Chung,Tung-Ho Wu,Kang-Ju Chou,Pin-Hong Lai,Chien-Fang Yang 대한영상의학회 2006 Korean Journal of Radiology Vol.7 No.2

Objective: We wanted to report our experience of metallic stent placement after insufficient balloon dilation in graft hemodialysis patients. Materials and Methods: Twenty-three patients (13 loop grafts in the forearm and 10 straight grafts in the upper arm) underwent metallic stent placement due to insufficient flow after urokinase thrombolysis and balloon dilation. The indications for metallic stent deployment included 1) recoil and/or kinked venous stenosis in 21 patients (venous anastomosis: 17 patients, peripheral outflow vein: four patients); and 2) major vascular rupture in two patients. Metallic stents 8 10mm in diameter and 40 80 mm in length were used. Of them, eight stents were deployed across the elbow crease. Access patency was determined by clinical follow-up and the overall rates were calculated by Kaplan-Meier survival analysis. Results: No procedure-related complications (stent fracture or central migration) were encountered except for a delayed Wallstent shortening/migration at the venous anastomosis, which resulted in early access failure. The overall primary and secondary patency rates ( standard error) of all the vascular accesses in our 23 patients at 3, 6, 12 and 24 months were 69% 9 and 88% 6, 41% 10 and 88% 6, 30% 10 and 77% 10, and 12% 8 and 61% 13, respectively. For the forearm and upper-arm grafts, the primary and secondary patency rates were 51% 16 and 86% 13 vs 45% 15 and 73% 13 at 6 months, and 25% 15 and 71% 17 vs 23% 17 and 73% 13 at 12 months (p = .346 and .224), respectively. Conclusion: Metallic stent placement is a safe and effective means for treating peripheral venous lesions in dialysis graft patients after insufficient balloon dilation. No statistically difference in the patency rates between the forearm and upper-arm patient groups was seen.

The development of Taiwan Fracture Liaison Service network

Lo-Yu Chang,Keh-Sung Tsai,Jen-Kuei Peng,Chung-Hwan Chen,Gau-Tyan Lin,Chin-Hsueh Lin,Shih-Te Tu,I-Chieh Mao,Yih-Lan Gau,Hsusan-Chih Liu,Chi-Chien Niu,Min-Hong Hsieh,Jui-Teng Chien,Wei-Chieh Hung,Rong-S 대한골다공증학회 2018 Osteoporosis and Sarcopenia Vol.4 No.2

Osteoporosis and its associated fragility fractures are becoming a severe burden in the healthcare system globally. In the Asian-Pacific (AP) region, the rapidly increasing in aging population is the main reason accounting for the burden. Moreover, the paucity of quality care for osteoporosis continues to be an ongoing challenge. The Fracture Liaison Service (FLS) is a program promoted by International Osteoporosis Foundation (IOF) with a goal to improve quality of postfracture care and prevention of secondary fractures. In this review article, we would like to introduce the Taiwan FLS network. The first 2 programs were initiated in 2014 at the National Taiwan University Hospital and its affiliated Bei-Hu branch. Since then, the Taiwan FLS program has continued to grow exponentially. Through FLS workshops promoted by the Taiwanese Osteoporosis Association (TOA), program mentors have been able to share their valuable knowledge and clinical experience in order to promote establishments of additional programs. With 22 FLS sites including 11 successfully accredited on the best practice map, Taiwan remains as one of the highest FLS coverage countries in the AP region, and was also granted the IOF Best Secondary Fracture Prevention Promotion award in 2017. Despite challenges faced by the TOA, we strive to promote more FLS sites in Taiwan with a main goal of ameliorating further health burden in managing osteoporotic patients.