Precise 5-Axis Grooving of Tire Mold Based on Surface Re-Parameterization

Chih-Hsing Chu,Chih-Hsin Hsu 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.

Grooving of tire mold is a complex machining process. The profile of a groove must be precisely formed on the road surface while the machining deviation of the wall surface must meet its design specifications. Previous tool path planning methods driven by optimization of machining errors perform unacceptably because of those restrictions. This paper proposes a new approach for precise 5-axis grooving of tire mold. Surface re-parameterization based on the two curve parameters of a ruled surface is applied to maximize the developability of the wall surface using Particle Swarm Optimization (PSO). The machining errors produced by moving the cutter along the resultant rulings is thus reduced. Grooving of a real tire mold demonstrates the effectiveness of the proposed approach.

FROM BUSINESS STRATEGY AND SOCIAL CAPITAL PERSPECTIVE TO TRAVEL AGENCIES’ COMPETITIVE ADVANTAGE

Chih-Hsing Liu,Jeou-Shyan Horng,Sheng-Fang Chou,Yung-Chuan Huang,Bernard Gan,Wei-Long Lee 글로벌지식마케팅경영학회 2018 Global Marketing Conference Vol.2018 No.07

Many firms see organizational learning systems as critical to facilitating competitive advantage. However, until now, few tourism studies have empirically investigated and identified how the different characteristics of highly competitive organizations, such as travel agencies, influence competitive advantage in a dynamic environment. This study uses a mediation-moderation analysis for such an empirical examination. A total of 288 travel agencies from Taiwan were analysed. The authors found that travel agencies’ shared goals may influence competitive advantage through characteristics of dynamic capability development, differential strategy implication and social capital accumulation. Greater levels of organizational learning may positively strengthen the relationships between (a) shared goals and dynamic capability, (b) shared goals and social capital, and (c) social capital and competitive advantage. Implications of these findings for managerial and theoretical frameworks are also discussed.

Modeling Torsional Strength of Reinforced Concrete Beams using Genetic Programming Polynomials with Building Codes

Hsing-Chih Tsai,Min-Chih Liao 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.8

The potential of using genetic programming to predict engineering data has caught the attention of researchers in recent years. This paper utilizes a derivative of genetic programming to model the torsional strength of reinforced concrete beams using polynomiallike equations. Furthermore, the calculation results of current building codes are introduced into the learning of input-output functional mapping as potential inputs to improve prediction accuracy and to suggest improvements to these building codes. The results show that introducing European building codes significantly improves the prediction accuracy to a level that is significantly above that achievable using the initial parameters alone. In addition, the results highlight that improvements of particular building codes are relevant to different parameter combinations. Moreover, suggestions for future modifications of European building codes were brought out.

Knowledge-based learning for modeling concrete compressive strength using genetic programming

Hsing-Chih Tsai,Min-Chih Liao 사단법인 한국계산역학회 2019 Computers and Concrete, An International Journal Vol.23 No.4

The potential of using genetic programming to predict engineering data has caught the attention of researchers in recent years. The present paper utilized weighted genetic programming (WGP), a derivative model of genetic programming (GP), to model the compressive strength of concrete. The calculation results of Abrams’ laws, which are used as the design codes for calculating the compressive strength of concrete, were treated as the inputs for the genetic programming model. Therefore, knowledge of the Abrams’ laws, which is not a factor of influence on common data-based learning approaches, was considered to be a potential factor affecting genetic programming models. Significant outcomes of this work include: 1) the employed design codes positively affected the prediction accuracy of modeling the compressive strength of concrete; 2) a new equation was suggested to replace the design code for predicting concrete strength; and 3) common data-based learning approaches were evolved into knowledge-based learning approaches using historical data and design codes.

Design Customization of Respiratory Mask based on 3D Face Anthropometric Data

Chih-Hsing Chu,Szu-Hao Huang,Chih-Kai Yang,Chun-Yang Tseng 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

This study presents a machine learning based method for design customization of a 3D respiratory mask. A parametric model of a3D human face was constructed from an anthropometric database consisting of 495 facial models. An AdaBoost.R algorithm wasapplied to identify a set of measurable parameters most related to the facial geometry. The correlation between parameters wasestimated using principal component analysis and linear regression. With those parameter values as input, the parametric modelgenerates 3D meshes of a human face that serve as a design reference for the construction of a customized respiratory mask of agood fit. We conducted a series of experiments with 10-fold cross-validation to validate the effectiveness of the proposed method.

Programming by Demonstration in Augmented Reality for the Motion Planning of a Three-Axis CNC Dispenser

Chih-Hsing Chu,Yu-Wang Liu,Pai-Chia Li,Liao-Chuan Huang,Yuan-Ping Luh 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.7 No.5

This study presents a programming by demonstration (PbD) interface in augmented reality for motion planning in a three-axis CNC glue dispenser. The interface assists a human planner to effectively determine dispenser motion in a planning task. An augmented reality application prompts the planner with instructive information in a video of real environment while guiding the machine in 3D space to dispense glue on a work part. The purpose involves facilitating the generation of the dispenser’s motion commands by enhancing individual spatial reasoning between the dispenser’s tip and the work part. CAD models are not required prior to the planning task, thus eliminating the use of motion planning software. Test results demonstrate the effectiveness of the proposed interface with respect to accelerating the process of the dispenser PbD. The study shows the practical value of augmented reality as a cost-effective interfacing technology for human–machine collaborations in smart manufacturing.

Polynomial modeling of confined compressive strength and strain of circular concrete columns

Hsing-Chih Tsai 사단법인 한국계산역학회 2013 Computers and Concrete, An International Journal Vol.11 No.6

This paper improves genetic programming (GP) and weight genetic programming (WGP) and proposes soft-computing polynomials (SCP) for accurate prediction and visible polynomials. The proposed genetic programming system (GPS) comprises GP, WGP and SCP. To represent confined compressive strength and strain of circular concrete columns in meaningful representations, this paper conducts sensitivity analysis and applies pruning techniques. Analytical results demonstrate that all proposed models perform well in achieving good accuracy and visible formulas; notably, SCP can model problems in polynomial forms. Finally, concrete compressive strength and lateral steel ratio are identified as important to both confined compressive strength and strain of circular concrete columns. By using the suggested formulas, calculations are more accurate than those of analytical models. Moreover, a formula is applied for confined compressive strength based on current data and achieves accuracy comparable to that of neural networks.

Geometry Optimization for a Rubber Mount with Desired Stiffness Values in Two Loading Directions Considering Hyperelasticity and Viscoelasticity

Liu Chih-Hsing,Hsu Yi-Yao,Yang Shih-Hao 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.3

Rubber mount is a type of vibration isolator that can absorb vibration and minimize external disturbance. This study proposes an optimization method to design the geometry of a rubber mount to achieve particular stiffness values in two different loading directions. The proposed objective function of the geometry optimization problem is to minimize the error ratios between calculated and target stiffness values in vertical and transverse directions; a weighted sum method is used to combine both error ratios with equal weighting factors. The design variables are the coordinates of some design points which form the cross-section geometry of the rubber mount. A three-dimensional design is then obtained by extrusion of the two-dimensional geometry. Cuckoo search algorithm is used to update the design variables until the objective function value is smaller than a tolerance. Nonlinear finite element analysis is used to estimate the stiffness values of the rubber mount. Both hyperelastic and viscoelastic rubber parameters are numerically identified by fitting to the experimental data. An optimal design of the rubber mount is obtained and prototyped. Experimental tests are performed to validate the design.

The Effect of the First Spontaneous Bacterial Peritonitis Event on the Mortality of Cirrhotic Patients with Ascites: A Nationwide Population-Based Study in Taiwan

( Tsung-hsing Hung ),( Chen-chi Tsai ),( Yu-hsi Hsieh ),( Chih-chun Tsai ),( Chih-wei Tseng ),( Kuo-chih Tseng ) 대한간학회 2016 Gut and Liver Vol.10 No.5

Background/Aims: Spontaneous bacterial peritonitis (SBP) contributes to poorer short-term mortality in cirrhotic patients with ascites. However, it is unknown how long the effect of the first SBP event persists in these patients. Methods: The National Health Insurance Database, derived from the Taiwan National Health Insurance Program, was used to identify and enroll 7,892 cirrhotic patients with ascites who were hospitalized between January 1 and December 31, 2007. All patients were free from episodes of SBP from 1996 to 2006. Results: The study included 1,176 patients with SBP. The overall 30-day, 90-day, 1-year, and 3-year mortality rates in this group were 21.8%, 38.9%, 57.5%, and 73.4%, respectively. The overall 30-day, 90-day, 1-year, and 3-year mortality rates in the non-SBP group were 15.7%, 32.5%, 53.3%, and 72.5%, respectively. After adjusting for gender, age, and other medical comorbidities, the adjusted hazard ratios of SBP for 30-day, 30- to 90-day, 90-day to 1-year, and 1- to 3-year mortality were 1.49 (95% confidence interval [CI], 1.30 to 1.71), 1.19 (95% CI, 1.02 to 1.38), 1.04 (95% CI, 0.90 to 1.20), and 0.90 (95% CI, 0.77 to 1.05), respectively, compared with the non-SBP group. Conclusions: The effect of SBP on the mortality of cirrhotic patients with ascites disappeared in those surviving more than 90 days after the first SBP event. (Gut Liver 2016;10:803-807)

Effects of aging on the phase transformation and sintering properties of coprecipitated Al₂O₃-ZrO₂ powders

Chih-Cheng Chen,Hsing-I Hsiang,Fu-Su Yen 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.1

In this study, the effects of aging on the crystalline phases, crystallite sizes and sintering properties of coprecipitated Al₂O₃- ZrO₂ powders are investigated using thermogravimetry (TG), differential thermal analysis (DTA), X-ray diffractometry (XRD), dilatometry, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Coprecipitated Al₂O₃- ZrO₂ powder aging in the solution promoted the dissolution and reprecipitation process, which resulted in the boehmite structure subsequently transforming into bayerite. The densification and microstructural development of the coprecipitated Al₂O₃-ZrO₂ powders were dependent upon the aging time which shifted the θ→α-Al₂O₃ phase transformation to a higher temperature, lowered the crystallite growth rate, and prevented the occurrence of intragranular ZrO₂ particles during sintering. In this study, the effects of aging on the crystalline phases, crystallite sizes and sintering properties of coprecipitated Al₂O₃- ZrO₂ powders are investigated using thermogravimetry (TG), differential thermal analysis (DTA), X-ray diffractometry (XRD), dilatometry, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Coprecipitated Al₂O₃- ZrO₂ powder aging in the solution promoted the dissolution and reprecipitation process, which resulted in the boehmite structure subsequently transforming into bayerite. The densification and microstructural development of the coprecipitated Al₂O₃-ZrO₂ powders were dependent upon the aging time which shifted the θ→α-Al₂O₃ phase transformation to a higher temperature, lowered the crystallite growth rate, and prevented the occurrence of intragranular ZrO₂ particles during sintering.