Novel Nonlinear Backstepping Control of Synchronous Reluctance Motor Drive System for Position Tracking of Periodic Reference Inputs with Torque Ripple Consideration

Chih-Hong Lin,Jung-Chu Ting 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.1

Owing to air-gap field harmonic, cogging torque, stator’s current time harmonic and the influence offlux saturation, a synchronous reluctance motor (SynRM) drive system has highly nonlinear uncertainties. Thus thelinear control method for the SynRM drive system is difficult to achieved good performance under the nonlinearuncertainty action. To obtain better control performance the novel nonlinear backstepping control system using upperbound with switching function is firstly proposed for controlling the SynRM drive system to prevail the lumpeduncertainty. With the proposed control system, the SynRM servo-drive system holds in robustness to uncertaintiesfor the tracking of periodic reference trajectories. To enhance the robustness of the SynRM drive system, the novelnonlinear backstepping control system using adaptive law is proposed for estimating the required lumped uncertaintyto reduce chattering phenomenon. When the inertia of the counterweight is varying, this proposed methodcan perform well in general situations, but cannot get a satisfactory performance. The novel nonlinear backsteppingcontrol system using reformed recurrent Hermite polynomial neural network with adaptive law and error estimatedlaw is thus proposed to estimate the lumped uncertainty and compensate estimated error for obtaining better controlperformance. Furthermore, two varied learning rates of the reformed recurrent Hermite polynomial neural networkis derived according to increment type Lyapunov function to speed-up parameter’s convergence. Finally, someexperimental results with comparative control performances are demonstrated, and then the effectiveness of theproposed control system with better control performance is verified for the position tracking of periodic referenceinputs with torque ripple consideration.

Scatternet Restructuring and Routing for Bluetooth Radio Systems

Chih-Yung Chang,Gwo-Jong Yu,Ching-Feng Lin,Tzu-Ting Wu 한국정보과학회 2002 한국정보과학회 학술발표논문집 Vol.2002 No.1

Pricing and Hedging European Energy Derivatives: A Case Study of WTI Oil Options

Chih-Chen Hsu,Shih-Kuei Lin,Ting-Fu Chen 한국증권학회 2014 Asia-Pacific Journal of Financial Studies Vol.43 No.3

This study extends the mean-reversion dynamic framework of (Pilipovic, Energy risk: Valuingand managing energy derivatives, 1997) and (Schwartz, The stochastic behavior of commodityprices: Implications for pricing and hedging, Journal of Finance 52, 1997, 923) and focuses ondeveloping a variety of continuous-time commodity-pricing and hedging models by analyzingthe pricing and hedging errors found in an empirical investigation of options contracts onlight sweet crude oil traded on the New York Mercantile Exchange. Thus, this study contributesto furthering the applicability of the models developed. The inclusion of the benchmarkBlack-Scholes pricing model generates systematic biases that are consistent with (Bakshi, Caoand Chen, Handbook of Quantitative Finance and Risk Management, 2010). The mean-reversionjump-diffusion and seasonality option-pricing model best describes the extreme pricevolatility experienced during a financial collapse, but the mean-reversion and seasonalityoption-pricing model offers the best pricing and hedging capability for other periods. Theperformances of hedging models are generally consistent with pricing errors.

Ultrasound imaging for inguinal hernia: a pictorial review

Wei-Ting Wu,Ke-Vin Chang,Chih-Peng Lin,Chi-Chuan Yeh,Özçakar Levent 대한초음파의학회 2022 ULTRASONOGRAPHY Vol.41 No.3

Inguinal hernia is the most prevalent type of abdominal wall hernia. Indirect inguinal hernia is twice as common as direct inguinal hernia. Computed tomography and magnetic resonance imaging can be used to evaluate inguinal hernia, but these modalities are greatly limited by their cost and availability. Ultrasonography has emerged as the most convenient imaging tool for diagnosing inguinal hernia due to its advantages, such as portability and absence of radiation. The present pictorial review presents an overview on the use of ultrasonography in the evaluation of inguinal hernia with a particular emphasis on the regional anatomy, relevant scanning tips, identification of subtypes, postoperative follow-up, and diagnosis of pathologies mimicking inguinal hernia.

INVESTIGATING SATISFIED BUT DISLOYAL BUSINESS CUSTOMERS

Ming-Chih Tsai,Rico Merkert,Shiau-Chi Lin,Mei-Ting Tsai 글로벌지식마케팅경영학회 2018 Global Marketing Conference Vol.2018 No.07

Satisfaction paradox indicates customer satisfaction does not necessarily translate into customer repurchase. Competitor’s attractiveness and customer demographics are two main moderators for the paradoxical phenomenon. Competitor’s attractiveness exhibits customer switching effect, whereas customer demographics imply customers moored with their current service provider. Still, the cases were few investigated in B2B settings where customers are in general more complex than consumers as involving more intricate organizational network influences. In a business network, transactions may incur buyer/seller relational activities that mitigate paradoxical behavior. Nonetheless, the variable is yet identified and the interacting effects between the moderating variables are not clarified. Thus, this study aims to develop an operational model to classify satisfied customers into loyal, moored and paradoxical segments using three genres of moderators: competitor’s attractiveness, organizational and transactional variables in a B2B setting. In the model, the theoretical bases of switching behaviors are applied for four statistical analysis executed in a logic sequence, including a factor analysis to consolidate quality measurements, a quadrant analysis to locate the effect of competitor’s attractiveness, a clustering analysis to segment satisfied customers into four segments, and finally, nonparametric tests to validate the organizational and transactional segmentation variables. Empirically, we study Taiwanese manufacturers who engaged in global trade and have had experiences in choosing the global air express services that form an oligopolistic market and a strategic group so competitor’s attractiveness can be better calibrated. A total of 180 valid samples are collected and analyzed. The results contribute to the literatures of B2B service marketing.

Concomitant Acromioclavicular and Coracoclavicular Ligament Reconstruction with a Duo-Figure-8 Autogenic Graft Wrapping Technique for Treating Chronic Acromioclavicular Separation

Fu-Ting Huang,Kai-Cheng Lin,Chih-Yang Lin,Wei-Ning Chang 대한정형외과학회 2021 Clinics in Orthopedic Surgery Vol.13 No.3

Background: Coracoacromial ligament transfer is the traditional procedure for treating chronic acromioclavicular separation, but it is significantly inferior to ligament reconstruction according to biomechanical and clinical studies. However, ligament reconstruction carries the risk of complications of graft loosening and peri-tunnel fractures. Currently, there is no ligament reconstruction procedure optimal for preventing such complications. The purpose of this study was to describe and retrospectively analyze the clinical and radiological outcomes of a “duo-figure-8” autogenic graft wrapping technique, which was used to concomitantly reconstruct the acromioclavicular and coracoclavicular ligaments. Methods: Preoperative, immediate postoperative, and final follow-up oputcomes were evaluated in 10 enrolled patients. Radiographic outcomes were indicated by the bilateral difference of the coracoclavicular distance (CCD) and overlapping length of the acromioclavicular joint (OLac). Quality of reduction was classified into 4 grades according to bilateral CCD difference into overreduction (< 0 mm), anatomic reduction (0–4 mm), partial loss of reduction (4–8 mm), and recurrent dislocation (> 8 mm). Clinical outcomes were evaluated using the American Shoulder and Elbow Surgeons (ASES) and Constant scores. Results: The mean side-to-side differences for CCD were 11.9 mm (preoperative), −0.1 mm (immediate postoperative), and 3.4 mm (final follow-up); those for OLac were 9.4 mm (preoperative) and 2.7 mm (final follow-up). CCD and OLac outcomes significantly improved at final follow-up (p < 0.05). At the immediate postoperative stage, 6 and 4 patients had overreduction and anatomic reduction, respectively. At final follow-up, 7 and 3 patients had anatomic reduction and partial loss of reduction, respectively. The magnitude of improvement of ASES scores for patients with anatomic reduction and partial loss of reduction (p = 0.20) was 18.1 and 20.0, respectively. The magnitude of improvement of Constant scores in patients with anatomic reduction and partial loss of reduction (p = 0.25) was 19.9 and 22.3, respectively. Conclusions: The technique yielded acceptable functional outcomes in patients with anatomic reduction or partial loss of reduction. The “duo-figure-8” wrapping method—a single autogenic tendon graft passing beneath the coracoid process with a tendonknot fixation over the distal clavicle and looping around the acromion intramedullary—did not increase the risk of peri-tunnel fractures over the clavicle, coracoid process, or acromion.

Risk of Hepatitis B Virus (HBV) Reactivation in HBsAg-Negative, Anti-HBc-Negative Patients Receiving Rituximab for Autoimmune Diseases in HBV Endemic Areas

Lan Ting-Yuan,Lin Yen-Chun,Tseng Tai-Chung,Yang Hung-Chih,Kao Jui-Hung,Cheng Chiao-Feng,Lee Tai-Ju,Huang Shang-Chin,Lu Cheng-Hsun,Li Ko-Jen,Hsieh Song-Chou 거트앤리버 소화기연관학회협의회 2023 Gut and Liver Vol.17 No.2

Background/Aims: Rituximab is known to be associated with high hepatitis B virus (HBV) reactivation rate in patients with resolved HBV infection and hematologic malignancy. However, data regarding HBV reactivation (HBVr) in rheumatic patients receiving rituximab is limited. To assess the HBVr rate in hepatitis B surface antigen (HBsAg)-negative patients receiving rituximab for autoimmune diseases in a large real-world cohort. Methods: From March 2006 to December 2019, 900 patients with negative HBsAg receiving at least one cycle of rituximab for autoimmune diseases in a tertiary medical center in Taiwan were retrospectively reviewed. Clinical outcome and factors associated with HBVr were analyzed. Results: After a median follow-up period of 3.3 years, 21 patients developed HBVr, among whom 17 patients were positive for hepatitis B core antibody (anti-HBc) and four were negative. Thirteen patients had clinical hepatitis flare, while eight patients had HBsAg seroreversion without hepatitis. Old age, anti-HBc positivity, undetectable serum hepatitis B surface antibody level at rituximab initiation and a higher average rituximab dose were associated with a higher HBVr rate. There was no significant difference in the HBVr risk between rheumatoid arthritis and other autoimmune diseases. Among anti-HBc-negative patients, subjects without HBV vaccination at birth had an increased risk of HBVr (4/368, 1.1%) compared with those who received vaccination (0/126, 0%). Conclusions: In HBV endemic areas where occult HBV is prevalent, anti-HBc-negative patients, may still be at risk for HBVr after rituximab exposure. HBVr may still be considered in HBsAgnegative patients developing abnormal liver function after rituximab exposure, even in patients with negative anti-HBc.

Clinical Significance of Smudge Cells in Peripheral Blood Smears in Hematological Malignancies and Other Diseases

Chang, Chih-Chun,Sun, Jen-Tang,Liou, Tse-Hsuan,Kuo, Chin-Fu,Bei, Chia-Hao,Lin, Sheng-Jun,Tsai, Wei-Ting,Tan, N-Chi,Liou, Ching-Biau,Su, Ming-Jang,Yen, Tzung-Hai,Chu, Fang-Yeh Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.4

Background: It is reported that the percentage of smudge cells in the blood smear could be a prognostic indicator in chronic lymphocytic leukemia. However, the clinical significance of smudge cells in other hematological malignancies, solid tumors or non-malignant diseases is less clear. Hence, this study was conducted to survey the clinical significance of smudge cells in hematological cancers and other disorders. Materials and Methods: From January to November, 2015, the clinical data of patients who received blood examination with differential counts for clinical purpose and were found to have smudge cells in the peripheral blood film in Far Eastern Memorial Hospital were selected. The percentage of smudge cells and patient outcomes were evaluated for further univariate and survival analyses. Results: A total of 102 patients with smudge cells in their blood smears were included. Smudge cells were frequently presented in out-of-hospital cardiac arrest (OHCA; n=30), infections (n=23), hematological cancers (n=23) and solid cancers (n=10). There was no relationship between the percentage of smudge cells and the patient mortality in all diseases (OR: 1.08, 95% CI: 0.47-2.48, P=1.000) as well as the OHCA group (OR: 1.91, 95% CI: 0.38-9.60, P=0.694). It was observed that in patients with all cancers with the percentage of smudge cells less than 50% had a lower mortality rate in comparison with those who had the percentage of smudge cells of 50% or more (OR: 22.29, 95% CI: 2.38-208.80, P<0.001). Additionally, it was seemingly that patients with smudge cells of 50% or more had a lower survival rate than those with smudge cells less than 50% in all cancers with follow-up at 2-month intervals, but without statistical significance (P=0.064). Conclusions: Our survey indicated that in all cancers, those who had higher percentage of smudge cells were prone to have poor outcomes when compared with the subjects with lower percentage of smudge cells. This finding was quite different from the results of previous studies in which the race-ethnicity of most study populations was non-Asian; hence, further investigations are required. Besides, there was no apparent association of the percentage of smudge cells with patient outcomes in all diseases, including OHCA.

Controlled Release of Clenbuterol from a Hydroxyapatite Carrier for the Treatment of Alzheimer’s Disease

Yi-Wen Lin,Chih-Hsiang Fang,Ya-Jyun Liang,Ching-Yun Yang,Wei-Ting Kuo,Feng-Huei Lin 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background Alzheimer’s disease is a neurodegenerative disorder, and Aβ aggregation is considered to be the central process implicated in its pathogenesis. Current treatments are faced by challenges such as serious side effects and reduced drug bioavailability. In this study, we developed a drug delivery system for intramuscular injection that uses cellular activity to achieve constant and long-term drug release. Methods Synthesized mesoporous hydroxyapatite (SHAP) was prepared via co-precipitation, and hydrophobic surface modification using stearic acid was then used to load clenbuterol by physical absorption, thus creating the drug delivery system. Clenbuterol release was achieved through cellular activity, with macrophage uptake triggering lysosome/endosome disruption, cytoplasmic release, extracellular exocytosis, and subsequent systemic circulation. Results We found that clenbuterol-loaded SHAP enabled sustained release for more than 2 weeks and effectively modulated inflammation, reduced Aβ oligomer-induced toxicity, and prevented Aβ aggregation. Conclusions Our findings suggest that treatment with clenbuterol loaded in this SHAP delivery system could be a promising strategy for treating Alzheimer’s disease.

Modified automotive organic friction materials through infiltration of liquid carbon precursors

이규정,Wu Ting-Yu,Lin Hsun-Yu,Cheng Huy-Zuㅍ,Wang Chih-Feng 한국탄소학회 2019 Carbon Letters Vol.29 No.4

This research combines the liquid carbon precursor infiltration process for carbon/carbon composites with the fabrication procedure for organic, carbon-matrix friction materials in automotive. In the densification process, different liquid carbon precursors and numbers of densification cycle are adopted to investigate the influence on physical and mechanical properties, microstructure and tribological behavior. Experimental results indicate that the infiltration of liquid carbon precursors could improve the physical, mechanical properties and tribological performances of organic friction materials. The open porosity decreases with the number of densification cycle. Both bulk density and hardness increase with the number of densification cycle. The resin-based specimens show higher hardness and lower open porosity than those of the pitch-based specimens after each densification cycle. The tribological measurement of specimens with different carbon precursors shows that the pitch-based specimen shows lower and more stable friction coefficients and exhibits lower weight losses in comparison with other carbon precursors. Morphological observations show that a large area of smooth lubricative film was easily presented on the worn surfaces of the pitch-based specimens, whereas it was seldom observed on the worn surfaces of the preform specimen and resin-based specimens.