The Technical Benefits of Future GNSS for Taiwan

Kai-Wei Chiang,Ming Yang,Meng-Lun Tsai,Yao-Yun Chang,Chi-Kuang Chu 한국항해항만학회 2006 한국항해항만학회 학술대회논문집 Vol.2 No.-

The next decade promises drastic improvements and additions to global navigation satellite systems (GNSS). Plans for GPS modernization include a civilian code measurement on the L2 frequency and a new L5 signal at 1176.45MHz. Current speculations indicate that a fully operational constellation with these improvements could be available by 2013. Simultaneously, the Galileo Joint Undertaking is in the development and validation stages of introducing a parallel GNSS called Galileo. Galileo will also transmit freely available satellite navigation signals on three frequencies and is scheduled to be fully operational as early as 2008. In other words, a dual system receiver (e.g., GPS+GALILEO) for general users can access six civil frequencies transmitted by at least fifty eights navigation satellites in space. The advent of GALILEO and the modernization of GPS raise a lot of attention to the study of the compatibility and interoperability of the two systems. A number of performance analyses have been conducted in a global scale with respect to availability, reliability, accuracy and integrity in different simulated scenarios (such as open sky and urban canyons) for the two systems individually and when integrated. Therefore, the scope of this article aims at providing the technical benefits analysis for Taiwan specifically in terms of the performance indices mentioned above in a local scale, especially in typical urban canyon scenarios. The conclusions gained by this study will be applied by the Land Survey Bureau of Taiwanese as the guideline for developing future GNSS tracking facilities and dual GNSS processing module for precise surveying applications in static and kinematic modes.

2022 Taiwan clinical multicenter expert consensus and recommendations for thyroid radiofrequency ablation

Wei-Che Lin,Wen-Chieh Chen,Pei-Wen Wang,Yi-Chia Chan,Yen-Hsiang Chang,Harn-Shen Chen,Szu-Tah Chen,Wei-Chih Chen,Kai-Lun Cheng,Shun-Yu Chi,Pi-Ling Chiang,Chen-Kai Chou,Feng-Fu Chou,Shun-Chen Huang,Feng 대한초음파의학회 2023 ULTRASONOGRAPHY Vol.42 No.3

Radiofrequency ablation (RFA) is a minimally invasive management strategy that has been widely applied for benign and recurrent malignant thyroid lesions as an alternative to surgery in Taiwan. Members of academic societies for specialists in interventional radiology, endocrinology, and endocrine surgery collaborated to develop the first consensus regarding thyroid RFA in Taiwan. The modified Delphi method was used to reach a consensus. Based on a comprehensive review of recent and valuable literature and expert opinions, the recommendations included indications, pre-procedural evaluations, procedural techniques, post-procedural monitoring, efficacy, and safety, providing a comprehensive review of the application of RFA. The consensus effectively consolidates advice regarding thyroid RFA in clinical practice for local experts.

Optimization of Triple Response Systems by Using the Dual Response Approach and the Hooke-Jeeves Search Method

Shu-Kai S. Fan,Chia-Fen Huang,Ko-Wei Chang,Yu-Chiang Chuang 대한산업공학회 2010 Industrial Engineeering & Management Systems Vol.9 No.1

This paper presents an extended computing procedure for the global optimization of the triple response system (TRS) where the response functions are nonconvex (nonconcave) quadratics and the input factors satisfy a radial region of interest. The TRS arising from response surface modeling can be approximated using a nonlinear mathematical program involving one primary (objective) function and two secondary (constraints) functions. An optimization algorithm named triple response surface algorithm (TRSALG) is proposed to determine the global optimum for the nondegenerate TRS. In TRSALG, the Lagrange multipliers of target (secondary) functions are computed by using the Hooke-Jeeves search method, and the Lagrange multiplier of the radial constraint is located by using the trust region (TR) method at the same time. To ensure global optimality that can be attained by TRSALG, included is the means for detecting the degenerate case. In the field of numerical optimization, as the family of TR approach always exhibits excellent mathematical properties during optimization steps, thus the proposed algorithm can guarantee the global optimal solution where the optimality conditions are satisfied for the nondegenerate TRS. The computing procedure is illustrated in terms of examples found in the quality literature where the comparison results with a gradient-based method are used to calibrate TRSALG.

Uniaxial Compression Properties and Compression Fatigue Performance of Selective Laser Melted Ti–6Al–4V Cellular Structure

Ming‑Wei Wu,Jhewn‑Kuang Chen,Mo‑Kai Tsai,Pei Wang,Tien‑Lin Cheng,Bo‑Huan Lin,Po‑Hsing Chiang,Annadurai Dhinakar 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.1

The selective laser melted (SLM) Ti–6Al–4V cellular solid is a promising material in biomedical and other applications. The mechanical properties of the SLM Ti–6Al–4V cellular material are predominantly controlled by the design of the cellular structure. The objective of this study was to investigate the uniaxial compressive properties and compressive fatigueperformance of the SLM Ti–6Al–4V cellular solid with a new cuboctahedron unit cell reinforced by four diagonal strutsand two horizontal struts along the X and Y axes. The infuences of hot isostatic pressing (HIP) on the various mechanicalproperties were also examined. The results showed a smoother stress–strain curve and fewer stress oscillations in the HIPspecimen than in the SLM specimen. The HIP process slightly decreased the yield strength of the SLM sample from 55 to52 MPa. Under uniaxial compressive stress, the SLM and HIP specimens exhibited layer-by-layer fracture and diagonalshear fracture, respectively. Furthermore, the HIP treatment signifcantly increased the fatigue performance and improved thefatigue endurance ratio at 106cycles from 0.15 to 0.35. The HIP treatment contributed to several positive efects, includingphase transformation from brittle α′ to α + β, the elimination of strut porosity and residual stress, an increase in lath size,and a better combination of strength and ductility, thereby improving the fatigue performance. The efects of stress mode onthe fracture mechanism were also clarifed using in situ observation in combination with digital image correlation.

The Antiproliferation Activity of Ganoderma formosanum Extracts on Prostate Cancer Cells

( Cheng-yen Chiang ),( Kai-di Hsu ),( Yen-yi Lin ),( Chang-wei Hsieh ),( Jui-ming Liu ),( Tze-ying Lu ),( Kuan-chen Cheng ) 한국균학회 2020 Mycobiology Vol.48 No.3

Androgen-independent prostate cancer accounts for mortality in the world. In this study, various extracts of a medical fungus dubbed Ganoderma formosanum were screened for inhibition of DU145 cells, an androgen-independent prostate cancer cell line. Results demonstrated that both hexane (GF-EH) and butanol (GF-EB) fraction of G. formosanum ethanol extract inhibited DU145 cell viability in a dose-dependent manner. GF-EH induced cell-cycle arrest in G1 phase of DU145 cells via downregulation of cyclin E2 protein expression. In addition, GF-EB triggered extrinsic apoptosis of DU145 cells by activating caspase 3 gene expression resulting in programed cell death. Above all, both GF-EH and GF-EB show lower toxicity to normal human fibroblast cell line compared to DU145 cell, implying that they possess specific drug action on cancer cells. This study provides a molecular basis of G. formosanum extract as a potential ingredient for treatment of androgen-independent prostate cancer.

Optimization of Triple Response Systems by Using the Dual Response Approach and the Hooke-Jeeves Search Method

Fan, Shu-Kai S.,Huang, Chia-Fen,Chang, Ko-Wei,Chuang, Yu-Chiang Korean Institute of Industrial Engineers 2010 Industrial Engineeering & Management Systems Vol.9 No.1

This paper presents an extended computing procedure for the global optimization of the triple response system (TRS) where the response functions are nonconvex (nonconcave) quadratics and the input factors satisfy a radial region of interest. The TRS arising from response surface modeling can be approximated using a nonlinear mathematical program involving one primary (objective) function and two secondary (constraints) functions. An optimization algorithm named triple response surface algorithm (TRSALG) is proposed to determine the global optimum for the nondegenerate TRS. In TRSALG, the Lagrange multipliers of target (secondary) functions are computed by using the Hooke-Jeeves search method, and the Lagrange multiplier of the radial constraint is located by using the trust region (TR) method at the same time. To ensure global optimality that can be attained by TRSALG, included is the means for detecting the degenerate case. In the field of numerical optimization, as the family of TR approach always exhibits excellent mathematical properties during optimization steps, thus the proposed algorithm can guarantee the global optimal solution where the optimality conditions are satisfied for the nondegenerate TRS. The computing procedure is illustrated in terms of examples found in the quality literature where the comparison results with a gradient-based method are used to calibrate TRSALG.

Comparison of Transforming Growth Factor-Beta1 and Lovastatin on Differentiating Mesenchymal Stem Cells toward Nucleus Pulposus-like Phenotype: An In Vitro Cell Culture Study

Shu-Hua Yang,Kai-Chiang Yang,Chih-Wei Chen,Ting-Chun Huang,Yuanhui Sun,Ming-Hsiao Hu 대한척추외과학회 2019 Asian Spine Journal Vol.13 No.5

Study Design: In vitro cell culture study. Purpose: This study aims to investigate the impact of transforming growth factor-beta1 (TGF-β1) and lovastatin on differentiating human mesenchymal stem cells (MSCs) toward nucleus pulposus (NP)-like phenotype. Overview of Literature: MSCs offer a cell source to the cell-based therapy for intervertebral disc degeneration. TGF-β1 is used to induce MSCs to differentiate into NP-like cells; however, an undesired expression of collagen type I has been reported. Statins reportedly stimulate expression of bone morphogenetic protein-2 (BMP-2) and promote the chondrogenic phenotype to NP cells. However, the effects of statins with or without TGF-β1 on the differentiation of MSCs into NP-like cells remain unclear. Methods: Human MSCs were treated with TGF-β1 alone, lovastatin alone, and simultaneous or sequential treatment with TGF-β1 and lovastatin. After the proposed stimulation, the total RNA was extracted to assess the expression profile of NP cells-specific genes. Hematoxylin–eosin staining was used for examining the microscopic morphology. Furthermore, we detected the syntheses of S-100 protein, aggrecan , and collagen type II in the extracellular matrix using immunohistochemical staining. Results: Simultaneous or sequential treatment of TGF-β1 and lovastatin could further augment the BMP-2 overexpression compared with lovastatin-alone treatment. However, the mRNA expression of aggrecan and collagen type II was not compatible with the expression level of BMP-2 . Immunohistochemical studies revealed compatible production of aggrecan, collagen type II , and S-100 protein in all three groups treated with lovastatin. Cells in groups treated with lovastatin were less populated than that in the group treated with TGF-β1 alone. Conclusions: This study demonstrates a promising role of lovastatin in inducing human MSCs into NP-like cells. However, further optimization of cell density before lovastatin treatment, treatment duration, and combination with TGF-β1 are warranted to attain better stimulatory effects.

Development of an Intelligent and Hybrid Scheme for Rapid INS Alignment

Yun-Wen Huang,Kai-Wei Chiang 한국항해항만학회 2006 한국항해항만학회 학술대회논문집 Vol.1 No.-

This article propose a new idea of developing a hybrid scheme to achieve faster INS alignment with higher accuracy using a novel procedure to estimate the initial attitude angles that combines a Kalman filter and Adaptive Neuro- Fuzzy Inference System architecture. A tactical grade inertial measurement unit was applied to verify the performance of proposed scheme in this study. The preliminary results indicated the outstanding improvements in both time consumption for fine alignment process and accuracy of estimated attitude angles, especially in heading angles. In general, the improvement in terms of time consumption and the accuracy of estimated attitude estimated accuracy reached 80% and 70% respectively during alignment process after compensating the attitude angles estimated by an extended Kalman filter with 15 states using proposed approach. It is worth mentioned that the proposed approach can be implemented in general real time navigation applications.

Female Breast Cancer Incidence Among Asian and Western Populations: More Similar Than Expected

Sung, Hyuna,Rosenberg, Philip S.,Chen, Wan-Qing,Hartman, Mikael,Lim, Wei-yen,Chia, Kee Seng,Wai-Kong Mang, Oscar,Chiang, Chun-Ju,Kang, Daehee,Ngan, Roger Kai-Cheong,Tse, Lap Ah,Anderson, William F.,Ya U.S. Dept. of Health, Education, and Welfare, Publ 2015 Journal of the National Cancer Institute Vol.107 No.7

<P><B>Background:</B></P><P>Previous reports suggested that female breast cancer is associated with earlier ages at onset among Asian than Western populations. However, most studies utilized cross-sectional analyses that may be confounded by calendar-period and/or birth cohort effects. We, therefore, considered a longitudinal (forward-looking) approach adjusted for calendar-period changes and conditioned upon birth cohort.</P><P><B>Methods:</B></P><P>Invasive female breast cancer data (1988–2009) were obtained from cancer registries in China, Hong Kong, South Korea, Taiwan, Singapore, and the United States. Age-period-cohort models were used to extrapolate longitudinal age-specific incidence rates for the 1920, 1944, and 1970 birth cohorts.</P><P><B>Results:</B></P><P>Cross-sectional age-specific incidence rates rose continuously until age 80 years among US white women, but plateaued or decreased after age 50 years among Asian women. In contrast, longitudinal age-specific rates were proportional (similar) among all Asian countries and the United States with incidence rates rising continuously until age 80 years. The extrapolated estimates for the most recent cohorts in some Asian countries actually showed later ages at onset than in the United States. Additionally, over successive birth cohorts, the incidence rate ratios (IRRs) for the longitudinal curves converged (narrowed) between Asian and US white women.</P><P><B>Conclusions:</B></P><P>Similar longitudinal age-specific incidence rates along with converging IRRs indicate that the age effects for invasive breast cancer are more similar among Asian and Western populations than might be expected from a solely cross-sectional analysis. Indeed, the Asian breast cancer rates in recent generations are even surpassing the historically high rates in the United States, highlighting an urgent need for efficient prevention and treatment strategies among Asian populations.</P>