New Method of Solving the Proper Rational Function and Application to Electrical Control System

Chen Chung-Cheng,Chen Yen-Ting 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.4

The paper is dedicated to develop a new method of addressing the linear nonhomogeneous time-invariant diff erential equation with same diff erential numbers for inputs and outputs. The Laplace transformed output of the electrical state-space equation is a rational function with the same degrees of the numerator and the denominator, and then the bored processes involving the long division of both complicated polynomials, the expanded multiplication of all polynomial factors, the diff erentiation of complicated polynomials and the complex derivations of all partial fraction parameters are inevitable for existing traditional methods. However, by applying the proposed method in this paper, we can explicitly express the general form of the desired output solution and directly solve the desired problem with shorter time than those traditional approaches. To give the signifi cant applications of the new proposed method, we apply it to address the famous electrical circuit based on our recent researches of Chen’s electrical unifying approach.

Validation of Pharyngeal Acid Reflux Episodes Using Hypopharyngeal Multichannel Intraluminal Impedance-pH

Yen-Yang Chen,Chen-Chi Wang,Ying-Cheng Lin,John Y Kao,Chun-Yi Chuang,Yung-An Tsou,Ja-Chih Fu,Sheng-Shun Yang,Chi-Sen Chang,Han-Chung Lien 대한소화기 기능성질환∙운동학회 2023 Journal of Neurogastroenterology and Motility (JNM Vol.29 No.1

Background/AimsHypopharyngeal multichannel intraluminal impedance-pH (HMII-pH) technology incorporating 2 trans-upper esophageal sphincter impedance channels has been developed to detect pharyngeal reflux. We used the HMII-pH technique to validate the candidate pharyngeal acid reflux (PAR) episodes based on the dual-pH tracings and determined the interobserver reproducibility. MethodsWe conducted a cross-sectional study in tertiary centers in Taiwan. Ninety patients with suspected laryngopharyngeal reflux and 28 healthy volunteers underwent HMII-pH test when off acid suppressants. Candidate PAR episodes were characterized by pharyngeal pH drops of at least 2 units and reaching a nadir pH of 5 within 30 seconds during esophageal acidification. Two experts manually independently identified candidate PAR episodes based on the dual-pH tracings. By reviewing the HMII-pH tracings, HMII-pH-proven PAR episodes were subsequently confirmed. The consensus reviews of HMII-pH-proven PAR episodes were considered to be the reference standard diagnosis. The interobserver reproducibility was assessed. ResultsA total of 105 candidate PAR episodes were identified. Among them 84 (80.0%; 95% CI, 71.0-87.0%) were HMII-pH-proven PAR episodes (82 in 16 patients and 2 in 1 healthy subject). Patients tended to have more HMII-pH-proven PAR episodes than healthy controls (median and percentile values [25th, 75th, and 95th percentiles]: 0 [0, 0, 3] vs 0 [0, 0, 0], P = 0.067). The concordance rate in diagnosing HMII-pH-proven PAR episodes between 2 independent observers was 92.2%. ConclusionOur preliminary data showed that 80.0% (71.0-87.0%) of the proposed candidate PAR episodes were HMII-pH-proven PAR episodes, among which the interobserver reproducibility was good.

Benefits and Harms of COVID-19 Vaccines in Cardiovascular Disease: A Comprehensive Review

Chung-Yen Chen,Ta-Chen Su 한국지질동맥경화학회 2023 지질·동맥경화학회지 Vol.12 No.2

Patients with a history of cardiovascular disease (CVD) who contract coronavirus disease 2019 (COVID-19) tend to have a worse prognosis and more severe cardiovascular side effects. COVID-19 vaccines, which are intended to prevent COVID-19, may also potentially reduce the severity and complications (including cardiovascular sequelae) of COVID-19, especially in patients with a history of CVD. However, there have also been reports of cardiovascular side effects from COVID-19 vaccines of various brands and types. The purpose of this study is to review the benefits and harms of COVID-19 vaccines in relation to CVD. In this thorough review of the most current evidence on the benefits and harms of COVID-19 vaccines, we present information about the characteristics of cardiovascular complications. Most of the evidence focuses on myocarditis or pericarditis, which are most strongly associated with mRNA vaccines and predominantly occur in young males within days of receiving the second dose. Meanwhile, post-vaccination myocardial infarction is more common in older males, and the first dose of adenoviral vector vaccines appears to play a greater role in this complication. This information may guide us in formulating alternative options and implementing targeted surveillance. Gaining more knowledge about the potential benefits and harms of COVID-19 vaccines will improve our ability to make informed decisions and judgments about the balance of these factors.

Fighting Against the Clock: Circadian Disruption and Parkinson’s Disease

Yen-Chung Chen,Simon J G Lewis,Shey-Lin Wu 대한파킨슨병및이상운동질환학회 2024 Journal Of Movement Disorders Vol.17 No.1

Circadian disruption is being increasingly recognized as a critical factor in the development and progression of Parkinson’s disease (PD). This review aims to provide an in-depth overview of the relationship between circadian disruption and PD by exploring the molecular, cellular, and behavioral aspects of this interaction. This review will include a comprehensive understanding of how the clock gene system and transcription–translation feedback loops function and how they are diminished in PD. The article also discusses the role of clock genes in the regulation of circadian rhythms, as well as the impact of clock gene dysregulation on mitochondrial function, oxidative stress, and neuroinflammation, including the microbiota-gut-brain axis, which have all been proposed as being crucial mechanisms in the pathophysiology of PD. Finally, this review highlights potential therapeutic strategies targeting the clock gene system and circadian rhythm for the treatment of PD.

The Effect of CdS QDs Structure on the InGaP/GaAs/Ge Triple Junction Solar Cell Efficiency

Chen-Chen Chung,Binh Tinh Tran,Hau-Vei Han,Yen-Teng Ho,Hung-Wei Yu,Kung-Liang Lin,Hong-Quan Nguyen,Peichen Yu,Hao-Chung Kuo,Edward Yi Chang 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.2

This work describes optical and electrical characteristics of InGaP/GaAs/Ge triple-junction (T-J) solar cells with CdS quantum dots (QDs) fabricated by a novel chemical solution. With the anti-reflective feature at long wavelength and down-conversion at UV regime, the CdS quantum dot effectively enhance the overall power conversion efficiency more than that of a traditional GaAs-based device. Experimental results indicate that CdS quantum dot can enhance the short-circuit current by 0.33 mA/cm2, which is observed for the triple-junction solar cells with CdS QDs of about 3.5 nm in diameter. Moreover, the solar cell conversion efficiency is improved from 28.3% to 29.0% under one-sun AM 1.5 global illumination I-V measurement.

Effect of the Circle-Grid Electrodes on Concentrated GaAs Solar Cell Efficiency

Chen-Chen Chung,Binh Tinh Tran,Ming-Hung Han,Kung-Liang Lin,Hung-Wei Yu,Yen-Teng Ho,Chun-Yen Chang,Edward Yi Chang 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.5

In this study, we investigate the effect of the shading factor of the front grid pattern on concentrated solar cell efficiency, taking the trade-off between the series resistance of the electrodes and the amount of incident light into consideration. We examine the thermal effect with regard to five different circle-grid electrode patterns of the front contact. The front contacts with different grid patterns affect the characteristics of light-concentratedtype GaAs single-junction solar cells. The device parameters analyzed include the open-circuit voltage (Voc), short-circuit current (Isc), fill factor (FF) and conversion efficiency (η). The results of our study show that for a concentration ratio greater than 60x with AM1.5G, the device with a shading factor of 7.1% has the best cell efficiency of 27.05%, due to the smaller current crowding at the center spot. The results indicate that the conversion efficiency of solar cells can be improved by establishing a compromise between the shading effect and the series resistance effect.

New Method of Designing Controller for Uncertain Diff erential-Diff erence Systems and Application to Time-Delay Operational Amplifi er System

Ke Jian,Chung-Cheng Chen,Yen-Ting Chen,Gui-hong Lin 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.6

This study combines the feedback linearization method and our recent researches of Chen electrical unifying approach to propose a global tracking controller design for nonlinear uncertain diff erential-diff erence systems with time delay. One example, which cannot be solved by the fi rst paper on the almost disturbance decoupling problem, is presented in this study to show the essential points that the tracking performance is easily solved by the proposed approach. The study applies Chen electrical unifying approach to take the place of using the disorganized virtual ground technique and the Kirchhoff ’s law for those traditional approaches. In order to show its signifi cant practicability, the study has fi rstly designed an easy-to-implement adder and a time-delay circuit, and an unstable time-delay operational amplifi er control system based on the Chen electrical unifying approach, and then has proposed a stable controller.

Research on Using Six Sigma Tool to Reduce the Core Process Time

Chung, Yi-Chan,Yen, Tieh-Min,Hsu, Yau-Wen,Tsai, Chih-Hung,Chen, Ching-Piao The Korean Society for Quality Management 2008 The Asian Journal on Quality Vol.9 No.1

When facing the global severe competition, the enterprises all try their best to upgrade the quality, reduce the costs to reach the goal of customer satisfaction. Motorola was the earliest firm creating the term Six Sigma (6 ${\sigma}$); GE was the enterprise successfully fulfilling Six Sigma. The success of these two firms revealed the prominent effects and became the world-class model enterprises. The main purpose of promoting Six Sigma activity was to reduce the possible defects in the business process to the least through designing and monitoring business process in order to reach the goals such as the best quality and efficiency, the lowest costs, the shortest circular process time, maximum profits and customer satisfaction. This research used the Six Sigma technique to improve the business process of ceramics manufacturing plant and find out the major factors of slower core task time by the analytical process of Process Mapping, Pareto Chart, Simu18 simulation software and figures and proposed the improvement measures. Through the confirmation of the case companies, it successfully reduced the core process time and the organizational costs and increased the capacity.

Stability of Shear Flow in a Vertical Heated Channel Filled with a Porous Medium

Yen Cho Chen,J. N. Chung 대한기계학회 1998 Heat transter conference Vol.4 No.1

Induction of Indoleamine 2,3-dioxygenase (IDO) Enzymatic Activity Contributes to Interferon-Gamma Induced Apoptosis and Death Receptor 5 Expression in Human Non-small Cell Lung Cancer Cells

Chung, Ting Wen,Tan, Kok-Tong,Chan, Hong-Lin,Lai, Ming-Derg,Yen, Meng-Chi,Li, Yi-Ron,Lin, Sheng Hao,Lin, Chi-Chen Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.18

Interferon-gamma (IFN-${\gamma}$) has been used to treat various malignant tumors. However, the molecular mechanisms underlying the direct anti-proliferative activity of IFN-${\gamma}$ are poorly understood. In the present study, we examined the in vitro antitumor activity of IFN-${\gamma}$ on two human non-small-cell lung carcinoma (NSCLC) cell lines, H322M and H226. Our findings indicated that IFN-${\gamma}$ treatment caused a time-dependent reduction in cell viability and induced apoptosis through a FADD-mediated caspase-8/tBid/mitochondria-dependent pathway in both cell lines. Notably, we also postulated that IFN-${\gamma}$ increased indoleamine 2,3-dioxygenase (IDO) expression and enzymatic activity in H322M and H226 cells. In addition, inhibition of IDO activity by the IDO inhibitor 1-MT or tryptophan significantly reduced IFN-${\gamma}$-induced apoptosis and death receptor 5 (DR5) expression, which suggests that IDO enzymatic activity plays an important role in the anti-NSCLC cancer effect of IFN-${\gamma}$. These results provide new mechanistic insights into interferon-${\gamma}$ antitumor activity and further support IFN-${\gamma}$ as a potential therapeutic adjuvant for the treatment of NCSLC.