Modified automotive organic friction materials through infiltration of liquid carbon precursors

Kuo‑Jung Lee,Ting‑Yu Wu,Hsun‑Yu Lin,Huy‑Zu Cheng,Chih‑Feng Wang 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.

Exploring the performance and competitiveness of Vietnam port industry using DEA

Kuo Kuo-Cheng,Lu Wen-Min,Le Minh-Hieu 한국해운물류학회 2020 The Asian journal of shipping and Logistics Vol.36 No.3

In the port industry, productivity is one of the vital factors for ports to develop competitiveness and market potential. The paper integrates context-dependent data envelopment analysis and forecasting models to conduct an efficient measurement of 53 Vietnamese ports and predict future performance in the port industry. By using the technique to get the measure of performance, this study builds the ports’ benchmark-learning stepping tools for the inefficient ports to enhance increasingly. The attractiveness and progress scores are resulted to assist the ports in situating themselves. Moreover, forecasting port performance results help decision-makers having more detailed information to make better decisions in their strategies and investments.

Thermal Stability, Adhesion and Electrical Studies on (Ti,Zr)Nx Thin Films as Low Resistive Diffusion Barriers between Cu and Si

Cheng-Lin Huang,Chih-Huang Lai,Po-Hao Tsai,Yu-Lin Kuo,Jing-Cheng Lin,Chiapyng Lee 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.3

In this study, we investigated the thermal stability, wettability, adhesion and reliability of (Ti,Zr)Nx films used as the diffusion barrier between Cu and Si. (Ti,Zr)Nx films were prepared by DC reactive magnetron sputtering from a Ti-5 at. % Zr alloy target in N2/Ar gas mixtures. A minimum film resistivity of 59.3 μΩ cm was obtained at an N2/Ar flow ratio of 2.75, which corresponds to the near stoichiometric composition (N/(Ti,Zr) ratio ~0.95). The sheet resistance of Cu/(Ti,Zr)N0.95/Si was not significantly increased until annealing above 750°C, indicating good thermal stability. On the other hand, the adhesion energy between Cu and the (Ti,Zr)Nx film was reduced as the N/Ti ratio was increased. To obtain reliable performance on stress-induced-voiding (SIV) and electromigration (EM) tests, we proposed to use (Ti,Zr)/(Ti,Zr)Nx/(Ti,Zr) tri-layers. We suggest that the interfacial adhesion between barrier and Cu plays an important role in reliability. The proposed tri-layer structure may be a promising candidate for a barrier, as it exhibits excellent reliability without increasing resistance.

Inhibiting the Growth of Cu3Sn and Kirkendall Voids in the Cu/Sn-Ag-Cu System by Minor Pd Alloying

Cheng En Ho,,Tsai Tung Kuo,Chun Chien Wang,Wei Hsiang Wu 대한금속·재료학회 2012 ELECTRONIC MATERIALS LETTERS Vol.8 No.5

In this study, the metallurgical reaction between Cu substrates (electrolytic type) and a Sn3Ag0.5Cu-xPd alloy at 180°C was examined using a scanning electron microscope (SEM), electron probe microanalyzer (EPMA),focused ion beam (FIB) microscope, and transmission electron microscope (TEM). The results showed that the growth of Cu3Sn in the Cu/Sn-Ag-Cu solder joints was substantially suppressed by doping with a minor quantity of Pd (0.1-0.7 wt. %) in the solder alloy. The sluggish growth of Cu3Sn reduced the formation of Kirkendall voids at the Cu/Cu3Sn interface and significantly improved the mechanical reliability of the joint interface. It was argued that a minor addition of Pd into the solder stabilized the Cu6Sn5 phase and enlarged the interdiffusion coefficient of Cu6Sn5 but diminished that of the neighboring phase (Cu3Sn), thereby decreasing the Kirkendall effect in the Cu/Sn-Ag-Cu reactive system.

UNDERSTANDING TOURIST SERVICE QUALITY PERCEPTIONS AND LOYALTY INTENTIONS IN THE INTERNATIONAL HOTEL SECTOR: APPLICATION OF DATA MINING METHODS AND KANO’S MODEL

Kuo-Chien Chang,Mu-Chen Chen,Nien-Te Kuo,Chia-Lin Hsu,Yi-Sung Cheng 글로벌지식마케팅경영학회 2014 Global Marketing Conference Vol.2014 No.1

This study used the methods of decision tree analysis, association rule analysis, and Kano’s model to explore the behavior patterns of mainland China tourists staying at the international tourist hotels in Taiwan. To this end, the data of their demographics, travel variables, overall satisfaction with the lodging experience, different service quality perceptions, and loyalty intentions were included. The decision tree analysis showed that a tourist’s overall satisfaction with the lodging experience, satisfaction with the quality of core intangible services, and certain demographic characteristics are three important determinants of tourist loyalty towards the hotels. In terms of the effect of demographics, the customers’ monthly income and length of stay at the hotel are two main determinants in this study. In addition, if the customer perceptions of different parts of hotel service quality are taken into account, among the five hotel service quality domains, core intangible services from the receptionist, housekeeping personnel, and food & beverage personnel are found to be important influences on hotel customer loyalty intention. In other words, high quality intangible services are important for luxury hotels to demonstrate their unique ability to help customers experience the service quality that creates loyalty intentions. With regard to the association rule analysis, the results showed that core intangible service aspects from the receptionist, housekeeping personnel, and food & beverage personnel are strongly associated with customer loyalty intentions, as are the tangible aspects of the reception and hotel room facilities. The former indicated that reception in the hotel lobby could be considered one of the most important servicescapes because of its impact in forming many of the first impressions of hotel guests, while the latter is treated as core offerings in hotels that would be encountered by most hotel customers. If the tourists are mainly from package tours, the intangible services and tangible facilities of these areas are the important areas to create customer satisfaction. However, if the tourists are mainly independent tourists because they have more time and free choice to stay at the hotel longer than the package tour tourists, the intangible services and tangible facilities of the entertainment or business centers would be even more important to these tourists than to the package tour tourists. With regard to Kano’s model analysis, the results showed that, based on mainland China tourists’ perceptions, most of the service elements fit into the category of one-dimensional quality attributes. This means that these service elements are positively and linearly related to customer satisfaction, and the greater fulfillment of the attribute results in a greater degree of satisfaction. This also means that hotels should make more effort to innovate their intangible services and tangible facilities to create business advantages in the market.

Optimization of the Needle Punching Process for the Nonwoven Fabrics with Multiple Quality Characteristics by Grey-Based Taguchi Method

Kuo, Chung-Feng Jeffrey,Su, Te-Li,Tsai, Cheng-Ping The Korean Fiber Society 2007 Fibers and polymers Vol.8 No.6

This study is intended for finding out the optimal processing parameters for needle punching nonwoven fabrics in order to work out its maximal strength. Taguchi method together with grey relational analysis is employed to resolve the problem as regards multiple-quality optimization, and further discover the optimal combination of processing parameters for needle punching nonwoven fabrics. Firstly, orthogonal array $L_{18}(2^1{\times}3^7)$ is used to deal with the processing parameters that may exert influence over the manufacturing of needle punching nonwoven fabrics. Then grey relational analysis is applied to resolve the deficiency of Taguchi method that focus on single quality characteristic. Next, the response table of grey relational analysis is used to obtain the optimal combination of processing parameters for multiple quality characteristics. In the current experiment quality characteristic refers to the tensile strength and tear strength of the nonwoven fabrics. Additionally, signal-to-noise ratio (SN ratio) calculation and analysis of variance (ANOVA) can be adopted to explore the experimental results. Through ANOVA, the significant factors that exert comparatively significant influence over the quality characteristic of the needle punching nonwoven fabrics, that is, the control factors are determined so that the quality characteristic of the needle punching nonwoven fabrics can be effectively controlled. Finally, confirmation experiment is conducted within 95 % confidence interval to verify the experimental reliability and reproducibility.

A Quantitative Vigilance Measuring Model by Fuzzy Sets Theory in Unlimited Monitoring Task

Cheng-Li Liu,Shiaw-Tsyr Uang,Kuo-Wei Su 대한산업공학회 2005 Industrial Engineeering & Management Systems Vol.4 No.2

Analysis and Construction of a Quality Prediction System for Needle-Punched Non-woven Fabrics

Kuo Chung-Feng Jeffrey,Su Te-Li,Chiu Chin-Hsun,Tsai Cheng-Ping The Korean Fiber Society 2007 Fibers and polymers Vol.8 No.1

In this study, polyester and polypropylene staple fibers were selected as the raw material, and then processed through roller-carder, cross-lapper and needle-punching machine to produce needle-punched non-woven fabrics. First, the experiment was planned using the Taguchi method to select processing parameters that affect the quality of the needle-punched non-woven fabric to act as the control factors for this experiment. The quality characteristics were the longitudinal and transverse tensile strength of the non-woven fabric as well as longitudinal and transverse tear strength. The $L_{18}(2^1{\times}3^7)$ orthogonal array was selected for the experiment as it offered an improvement on the traditional method that wastes a lot of time, effort and cost. By using the analysis of variance(ANOVA) technique at the same time, the effect of significant factors on the production process of needle-punched non-woven fabrics could be determined. Finally, the processing parameters were set as the input parameters of a back-propagation neural network(BPNN). The BPNN consists of an input layer, a hidden layer and an output layer where the longitudinal/transverse tensile and tear strength of the non-woven fabric were set as the output parameters. This was used to construct a quality prediction system for needle-punched non-woven fabrics. The experimental results indicated that the prediction system implemented in this study provided accurate predictions.

Influence of Base Oil Structure on Engine Deposits

Cheng Kuo 한국트라이볼로지학회 2008 Lubricants SYMPOSIUM Vol.2008 No.10

FeCoHfN Soft Magnetic Thin Films with High Frequency Characteristics

Cheng-Lun Kuo,Shandong Li,Jenq-Gong Duh 한국자기학회 2007 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-