Chongbin Hou, Yang Qiu, Xingyan Zhao, Shaonan Zheng, Yuan Dong, Qize Zhong and Ting Hu
By investigating the thermal-mechanical interaction between the through silicon via (TSV) and the Cu pad, this study aimed to determine the effect of electroplating defects on the…
Abstract
Purpose
By investigating the thermal-mechanical interaction between the through silicon via (TSV) and the Cu pad, this study aimed to determine the effect of electroplating defects on the upper surface protrusion and internal stress distribution of the TSV at various temperatures and to provide guidelines for the positioning of TSVs and the optimization of the electroplating process.
Design/methodology/approach
A simplified model that consisted of a TSV (100 µm in diameter and 300 µm in height), a covering Cu pad (2 µm thick) and an internal drop-like electroplating defect (which had various dimensions and locations) was developed. The surface overall deformation and stress distribution of these models under various thermal conditions were analyzed and compared.
Findings
The Cu pad could barely suppress the upper surface protrusion of the TSV if the temperature was below 250 ?. Interfacial delamination started at the collar of the TSV at about 250 ? and became increasingly pronounced at higher temperatures. The electroplating defect constantly experienced the highest level of strain and stress during the temperature increase, despite its geometry or location. But as its radius expanded or its distance to the upper surface increased, the overall deformation of the upper surface and the stress concentration at the collar of the TSV showed a downward trend.
Originality/value
Previous studies have not examined the influence of the electroplating void on the thermal behavior of the TSV. However, with the proposed methodology, the strain and stress distribution of the TSV under different conditions in terms of temperature, dimension and location of the electroplating void were thoroughly investigated, which might be beneficial to the positioning of TSVs and the optimization of the electroplating process.
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Jaw-Ren Lin, Tzu-Chen Hung and Shu-Ting Hu
This paper aims to study the inertia squeeze film characteristics between ferrofluid-lubricated circular stepped disks. Owing to the development of modern machine systems, the…
Abstract
Purpose
This paper aims to study the inertia squeeze film characteristics between ferrofluid-lubricated circular stepped disks. Owing to the development of modern machine systems, the application of ferrofluids has received great attention. Because the circular disks are a special situation of circular stepped squeeze films, a further study of fluid inertia force effects on the ferrofluid-lubricated circular stepped squeezing mechanism is motivated.
Design/methodology/approach
On the basis of the ferrohydrodynamic flow model of Shliomis incorporating the momentum integral method, the effects of fluid inertia forces in ferrofluid-lubricated circular stepped squeeze films in the presence of external magnetic fields are investigated in this study. Analytical solutions of squeeze film performances are derived.
Findings
The fluid inertia force effects provide an increased load capacity and a longer squeeze film time for the ferrofluid-lubricated circular stepped squeeze film, especially for a larger value of the inertia parameter, the Langevin parameter and the volume concentration and a smaller value of the radius ratio and the step height ratio.
Originality/value
For engineering applications, numerical tables for squeeze film loads of circular stepped disks are also provided in this paper.
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K. Viswanath Allamraju and Srikanth Korla
Purpose is to design the energy harvesters and to know the limit of the application of load on the PZT material. Fatigue failures of the designed products is merely bothering the…
Abstract
Purpose
Purpose is to design the energy harvesters and to know the limit of the application of load on the PZT material. Fatigue failures of the designed products is merely bothering the modern engineers and scientists for the research communities of all fields. Especially in the field of Micro Electromechanical Systems (MEMS), durability of low power systems is very important under the climates of both at high temperature and low temperature zones. And also continuous electrical power requirement is important for the MEMS and wireless sensor networks. Electricity is the greatest crisis in the world on one side and on the other side, durability of smart devices such as mobile phones, laptops, compact devices, computer spare parts are unrecyclicable batteries for reducing the rate of pollution in the environment.
Design/methodology/approach
By considering these problems, authors have taken up a research in finding the first fatigue characteristics, which are fatigue failure and durability of ferroelectric material as lead zirconate titanate, and then designed the scavenging device by using harmonically excited vibrations for getting optimum power output which is about 15.6 mW.
Findings
Under the resonance operated condition at the frequency of about 50 Hz, a prototype of scavenging device is about 90 V AC peak-to-peak voltage and the durability of scavenging device is 9.715 years.
Originality/value
Durability of PZT at different environmental conditions plays a very important role for the continuous function of low power devices. The output of PZT may change when the working time increases in addition with the mechanical properties.
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In the summer of 1995, shortly after the UN launched the Decade for Human Rights Education,Henry Steiner, Director of Harvard University’s Law School Human Rights Program…
Abstract
In the summer of 1995, shortly after the UN launched the Decade for Human Rights Education,Henry Steiner, Director of Harvard University’s Law School Human Rights Program, provided added momentum for the campaign with these words of inspiration, “As little as two years ago, rare was the university whose curricula included human rights studies. Much has changed, to the point where one no longer questions why such studies should be offered but rather how they could be ignored.” While this is not entirely the case for the whole of universities spanning the globe, including Bulgaria, it does point favorably towards a growing mentality in the importance of human rights education. Grasping the significance of human rights education is an essential component for the full manifestation of human rights, and unfortunately, it is an element still missing. This, in a time when society should be moving to the next dimension‐beyond what we already know to be necessary to creating the reality that is, specific action towards implementation of human rights education. Perhaps then, it can only move us closer to fruition to question and unearth the road blocks to the realization of human rights education.
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Ting‐Ting Hu, Bin Xiang, Shi‐Guo Liao and Wen‐Zhang Huang
The purpose of this paper is to research the corrosion behavior of AM60B magnesium alloy in simulated acid rain. Specifically, this paper aims to investigate the effect of pH on…
Abstract
Purpose
The purpose of this paper is to research the corrosion behavior of AM60B magnesium alloy in simulated acid rain. Specifically, this paper aims to investigate the effect of pH on the corrosion behavior of the alloy.
Design/methodology/approach
Electrochemical methods and surface analysis were applied to study the corrosion behavior of AM60B magnesium alloy in simulated acid rain.
Findings
Results showed that changes in pH can influence the corrosion potential and corrosion current of the alloy. In particular, the anodic process was affected. The protective film on the surface of AM60B magnesium alloy was destroyed in simulated acid rain. The type of corrosion attack observed on the surface of the alloy was pitting damage. Numerous deep pits were formed on the surface. Corrosion products were mainly composed of MgO and MgAl2(SO4)4 · 2H2O.
Originality/value
The paper provides fundamental experimental data for clarifying the mechanism of the effects of acid rain on the corrosion of magnesium alloys.
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Wenhang Li, Jing Wu, Ting Hu and Feng Yang
This paper aim to build an information fusion model that can predict the bottom shape of welding groove for better welding quality control. Arc sensor is widely used in seam…
Abstract
Purpose
This paper aim to build an information fusion model that can predict the bottom shape of welding groove for better welding quality control. Arc sensor is widely used in seam tracking due to its simplicity and good accessibility, but it heavily relies on the bottom shape of the groove. It is necessary to identify the welding groove bottom state. Therefore, arc sensor information and vision sensing information were fused by the rough set (RS) method to predict the groove state, which will lay the foundation for better welding quality control.
Design/methodology/approach
First, a multi-sensor information system was established, which included an arc sensing component and a vision sensing component. For the arc sensing system, the current waveform in each rotating period was obtained and divided into 12 parts to calculate variables representing the variation of arc length. For the vision sensing system, images were obtained by passive vision when the arc was near the groove sidewall. The positions of the sidewall and the arc were calculated to get the weld deviation which was unrelated with the bottom groove state. Second, experimental data were generated by workpiece with various bottom shapes. At last, the RS method was adopted to fuse the arc sensing and the vision information, and a rule-based model with good prediction ability was obtained.
Findings
By fusing arc sensing and vision sensing information, an RS-based model was built to predict the welding groove state.
Originality/value
The RS modeling method was used to fuse arc sensing information and vision sensing information to build a model that predicts groove bottom state. The arc sensing information represented the arc length variation, while the vision sensing information contains the seam deviation which was unrelated with the bottom groove state. The RS model gives satisfactory prediction results and can be applied to weld quality control.
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Meng-Lei Monica Hu, Ting-Kuo Chen and Tsung-Lin Ou
The purpose of this research is to evaluate the perceptions of local tourists concerning the importance and performance of their dining experience and restaurant selection factors…
Abstract
The purpose of this research is to evaluate the perceptions of local tourists concerning the importance and performance of their dining experience and restaurant selection factors at tourist destinations. Five hundred forty-one questionnaires collected from a series of on-site surveys at popular tourist destinations were analyzed. The results of importance–performance analysis (IPA) illustrate that no attribute fell in the Concentrate Here quadrant; staff service, service speed, food quality, interior design, comfort, cleanliness, restaurant scent, food scent attributes, and the “food service” factor fell under the Keep up the Good Work quadrants; noise, music, new experience, price attributes, and the “servicescape” factor fell in the Low Priority quadrant; servicescape lighting fell in the Possible Overkill quadrant. In conclusion, restaurants at popular tourist destinations have done very well in most service items and seem to have reached the professional standards expected by mass tourists.
Tatjana Thimm and Ralf Seepold
The purpose of this paper is to find out tourism movement patterns via the tracking of tourists with the help of positioning systems like GPS in the rural area of the Lake…
Abstract
Purpose
The purpose of this paper is to find out tourism movement patterns via the tracking of tourists with the help of positioning systems like GPS in the rural area of the Lake Constance destination in Germany. In doing so past, present and future of tourist tracking is illustrated.
Design/methodology/approach
The tracking is realized via common smartphones extended by an app, with dedicated sensors like position loggers and a survey. The three different approaches are applied in order to compare and cross-check results (triangulation of data and methods).
Findings
Movement patterns turned out to be diverse and individualistic within the rural destination of Lake Constance and following an ants trail in sub-destinations like the city of Constance. Repeat visitors and first-time visitors alike always visit the bigger cities and main day-trip destinations of the Lake. A possible prediction tool enables new avenues of governing tourism movement patterns.
Research limitations/implications
The tracking techniques can be developed further into the direction of “quantified self” using gamification in order to make the tracking app even more attractive.
Practical implications
An algorithm-based prediction tool would offer new perspectives to the management of tourism movements.
Social implications
Further research is needed to overcome the feeling of invasiveness of the app to allow tracking with that approach.
Originality/value
This study is original and innovative because of the first-time use of a smartphone app in tourist tracking, the application on a rural destination and the conceptual description of a prediction tool.
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Rocío Martínez Suárez, José Alberto Castañeda García and Miguel Ángel Rodríguez Molina
Knowing the behavior of tourists visiting cultural destinations enables better management of tourist flows, a better understanding of areas with greater tourist density and an…
Abstract
Purpose
Knowing the behavior of tourists visiting cultural destinations enables better management of tourist flows, a better understanding of areas with greater tourist density and an opportunity to decongest popular neighborhoods. The purpose of this study is to segment tourists according to their spatio-temporal behavior and identify the primary variables that characterize the resulting segments, which will help urban destinations prevent problems arising from the saturation of tourists in certain areas.
Design/methodology/approach
To do this, this paper analyzes the behavior of tourists visiting the southeastern Spanish city of Granada, one of the most highly visited cultural tourism destinations. The data analysis used the methodology of sequence alignment which is used to identify segments as a function of their contained elements and the order in which these appear.
Findings
The results demonstrate the existence of three segments with different behavioral patterns: the “explorer tourists” segment, the “non-traditional cultural tourists” segments and the “typical cultural tourists” segment. These segments show differences in the concentration of their visits. This study discovered that the segments that visit a greater number of destination areas are those with less cultural orientation, higher travel budgets and younger and more frequent visitors.
Originality/value
In the segmentation not only keep in mind the visited areas, but the order in which they were visited as well. In addition, one should consider the time that each tourist remains in each relevant zone of the destination, given that the visiting time is an important variable to assess the congestion of an area.
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Yaw A. Debrah and Ian G. Smith
Presents over sixty abstracts summarising the 1999 Employment Research Unit annual conference held at the University of Cardiff. Explores the multiple impacts of globalization on…
Abstract
Presents over sixty abstracts summarising the 1999 Employment Research Unit annual conference held at the University of Cardiff. Explores the multiple impacts of globalization on work and employment in contemporary organizations. Covers the human resource management implications of organizational responses to globalization. Examines the theoretical, methodological, empirical and comparative issues pertaining to competitiveness and the management of human resources, the impact of organisational strategies and international production on the workplace, the organization of labour markets, human resource development, cultural change in organisations, trade union responses, and trans‐national corporations. Cites many case studies showing how globalization has brought a lot of opportunities together with much change both to the employee and the employer. Considers the threats to existing cultures, structures and systems.