Optimization Parameters of Milling Process of Mould Material for Decreasing Machining Power and Surface Roughness Criteria

Improving milling performances is an effective solution to decrease the costs required. This paper addressed a multi-response optimization to simultaneously decrease the machining power consumed Pm, arithmetical roughness Ra, and ten-spot roughness Rz. The Grey-Response Surface Method-Multi Island Genetic Algorithm (GRMA) consisting of grey relational analysis (GRA), response surface method (RSM), and multi-island genetic algorithm (MA) was proposed to predict the optimal parameters and yield optimum milling performances. The experimental trials were conducted with the support of a CNC milling center. The influences of spindle speed (S), depth of cut (ap), feed rate (fz), and tip radius (r) were explored using GRA. The nonlinear relationship between machining parameters and grey grade (GG) model was developed using RSM. Finally, two optimization techniques, including desirability approach (DA) and MA were performed to observe the optimal values. The results indicated that the machining power was greatly affected by processing factors and the radius has a significant impact on the roughness criteria. The measured reductions using optimal parameters of Pm, Ra, and Rz are approximately 77.05%, 50.00%, and 58.02%, respectively, as compared to initial settings. The GRMA can be considered as an effective approach to generate reliable values of processing conditions and technological performances in the milling process

Government’s and professional associations’ roles in promoting corporate social resposibility – An exploratory in Vietnamese construction firms

With this large number of operating company, the construction industry in Vietnam needs the direction and supports from the government and professional associations not only in policies, business strategies, information about construction but also in leading and providing CSR information and instruction. By employing qualitative approach with in-depth interview as the main method to collect data, this study is to explore actual managers’ perspectives of the current roles of these two stakeholders in CSR and their expectations for the upcoming years. Two worthy notes need to be concerned. The first note is that the roles of government are really important in issuing appropriate policies and treating businesses fairly. Another note relating that of professional associations points out that construction firms do not have any belief in their operations

Influences of social ties on firms’ performance - A study in Vietnam on corporate social responsibility practices

Social ties and their influences on firm’s performance are still issues of many debates. The reason is that previous studies gave different findings about the effects of social ties on firm’s performance. This study, therefore, focuses on finding what managers in construction firms perceive of social ties in their business and how these ties affect corporate social responsibility (CSR) practices – an aspect of firm’s performance. To address these research objectives, qualitative approach is employed and in-depth interview with managers in construction firms is conducted to collect the data. Furthermore, the study also explores how managers think of CSR changes in the near future. The research findings show that interviewees strongly believe in CSR changes including both internal and external changes. In terms of social ties, the research also identifies government authorities and professional associations; and business partners as political and business ties, respectively. The findings show that managers easily realize business ties and their effects on CSR practices. Meanwhile, only some managers with years of seniority can perceive of political ties and their effects. The research findings also suggest some noteworthy issues for the authorities of the industry to consider including lack of information among managers about firm’s aspects and relationships, and the significance of professional associations (a type of political ties) although these ties currently have no influences on CSR practices of construction businesses

Tariff-based load shifting for domestic cascade heat pump with enhanced system energy efficiency and reduced wind power curtailment

Cascade air-to-water heat pumps may have good potential for retrofitting UK domestic buildings because they can directly replace existing fossil-fuel boilers without the requirement of considerable modifications to heat distribution systems. A widespread uptake of these heat pumps, however, would pose challenges to the grid. Furthermore, wind power generation has increased in the UK to achieve the target of decreasing CO2 emissions by 2050, but there are high levels of wind curtailment due to the mismatch between electricity supply and demand. In this paper, a load shifting study for cascade heat pumps coupled with thermal energy storage addressing these issues is presented. The main objective is to find the best tariff-based schedule load shifting for cascade heat pumps, which can help to avoid peak demand periods while obtaining enhanced system energy efficiency with minimised running costs and reduced wind energy curtailment. How the retrofit performance of the cascade heat pumps with load shifting is further investigated. TRNSYS was used to simulate the system performance validated against experimental results. Northern Ireland (UK) was selected as the evaluated scenario. Simulation results showed that the tank temperature set point of 75 °C and the storage size of 1.2 m3 could wholly shift the cascade heat pumps’ operation to off-peak periods. The best times to start the cascade heat pumps to charge the storage were at 3 am and 2 pm for the morning and afternoon heating demands, respectively. Compared to oil boilers, the cascade heat pumps with load shifting could obtain lower running costs (16–34%) and carbon emissions (20–37%)

NGO Visit to Vietnam, 14-21 May 1991: Observations and Comments

A team of six representatives from non-governmental organizations (NGOs) in the United States, Canada and Australia visited Vietnam from 14 to 21 May 1991, to assess the situation of people who have returned under the voluntary repatriation program established by the Comprehensive Plan of Action (CPA) for Indochinese refugees

Controllable Optical Properties of Multiple Electromagnetically Induced Transparency in Gaseous Atomic Media

The advent of electromagnetically induced transparency (EIT) offered a new coherent material with exotic and controllable optical properties. Although, studies on single-EIT are described in detail for single-EIT, however, extension from single- to multi- EIT is currently of current interest due to it gains advantages in multi-channel optical communication, waveguides for optical signal processing and multi-channel quantum information processing. In this work, we review recent research works concerning multi-EIT and some related applications, as controlling group velocity of light, giant Kerr nonlinearity, optical bistability. A special attention of the review also gives for analytical interpretations of EIT spectrum, its dispersion and related applications such as EIT enhanced Kerr nonlinearity and optical bistability to give physics insight. From experimental point of view, a latest development for measuring multi-EIT spectrum and its dispersion in hot medium is presented and compared to theoretical analytical representations

Reasons for customers reluctance to use electronic payments – A study in Ho Chi Minh City

This study aims to investigate reasons why customers are reluctant to use e-payment and how these reasons explain their impacted values, with the following research objectives: (1) to identify characteristics of electronic payment generating the resistance of customers to this E-payment; (2) to explore the connections between those characteristics and values of individuals through the consequences of these characteristics; (3) to propose suggestions for service providers and financial institutes to develop appropriate strategic plans to motivate e-payment in Vietnam. To address these research objectives, the means-end chain (MEC) theory is employed with hard laddering interviews as data collection methods. Then, the collected data are analyzed by the Association Pattern Technique (APT) and used to build the Hierarchical Value Map (HVM). The HVM indicates five main reasons which bar customers from using e-payment: (1) lack of information about e-payment and its benefits, (2) security vulnerabilities in online payment systems, (3) unavailability of legal laws to protect e-payment users, (4) unpopularity of e-payment, and (5) transaction fees and no discount for e-payment. The Value map also revealed that Safety is the most crucial value explaining why most customers are unwilling to use e-payment. Besides, the respondents also care about the Economy and the Convenience of e-payment. From these findings, the study offers some suggestions for banks and service providers to increase the popularity of e-payments

The influence of economic factors on the sustainable energy consumption: evidence from China

Recently, sustainable energy consumption has been a significant factor in reducing environmental degradation due to the high economic growth, and this phenomenon demands more attention of scholars and policymakers. Thus, the current literature examines the impact of economic factors such as economic growth, foreign direct investment (FDI), inflation, and population growth on sustainable energy consumption (SEC), particularly in renewable energy consumption (REC) in China. This study used secondary data collection methods extracted from world development indicators (WDI), incorporating stationary tests like Phillips-Perron (PP) and Augmented Dickey-Fuller (ADF) to check the unit root of the constructs. The time-series data involved are from 1981 to 2019. The autoregressive distributed lag (ARDL) model was utilized to examine the association among the variables. The results indicated that economic growth, FDI, inflation, and population growth were positively associated with SEC in China. This study provides the guidelines to the policymakers to develop policies related to the SEC