1,315 research outputs found

    Multi-Attribute Optimization of the WEDM Process for Surface Characteristics and Productivity

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    Wire-cut electrical discharge machining (WEDM) process is a proficient operation for the precise manufacturing of complex profiles of difficult-to-cut materials. The purpose of the current paper is to determine optimal processing inputs, including the WEDM current (CU), WEDM voltage (DV), pulse duration (Ton), and the speed of the wire electrode (WS) to decrease the depth of the recast layer (DL) as well as the root mean square roughness (RMSR) and enhance the cutting speed (CS) of the WEDM operation. The radius basis function (RBF) approach is employed to develop the predictive models of technical responses. The non-dominated sorting particle swarm optimization (NSPSO) is applied to obtain the optimal values of processing inputs and WEDM performances measured. The findings revealed that the proposed RBF models significantly contribute to the accurate prediction for the WEDM outputs. The optimal values of the CU, Ton, DV, and WS are 5.0 A, 6.0 μs, 33.0 V, and 4 m/min, respectively.The optimized values of the RMSR and DL are decreased by 60.98% and 15.55%, respectively, while the CS is enhanced by 8.90%. This work can be listed as an alternative solution for improving the surface characteristics and productivity of the WEDM process

    The Capability of E-reviews in Online Shopping. Integration of the PLS- SEM and ANN Method

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    Purpose: The aim of this study is to investigate the impact of e-review on iGen's propensity to purchase online. Especially, it can be better understood by dissecting the relationship among 3 variables of e-review (review valence, quantity of e-review and quality of e-review), e-satisfaction, and intention to buy.   Theoretical framework: This study classifies e-reviews according to their valence, quantity, and quality based on the study of Khammash (2008).   Design/methodology/approach: The PLS-SEM method was used to analyze data collected from online surveys administered to a sample of 222 iGen in Ho Chi Minh City to assess the hypotheses behind the study. Additionally, the Artificial Neural Network technique was used to separate SEM predictors that were relatively important.   Findings:  There are three results from the investigation: It has been found that (1) e-satisfaction is positively affected by valence, (2) e-satisfaction is generally increased with the high quality of e-review, but the quantity of e-review does not necessarily affect customers' e-satisfaction, and (3) e-satisfaction given in the context of an e-commerce platform has a strong effect on customers' online shopping intention. This study sheds new light on iGen's online buying habits and offers valuable management implications for iGen, online merchants, and e-commerce sites.   Research, Practical & Social implications:  E-reviews have become a significant factor in determining consumers' online purchase decisions. They also assist iGen in understanding how a qualified e-review—one that is clear, understandable, helpful, and has enough justification to support the opinions—will be advantageous for other consumers who wish to shop online.   Originality/value:  Provides the theory of e-review and its role in the online business environment. In addition, understand more about the behavior of igen, an age with a huge amount of spending on an online shopping platform

    Zooplankton from Can Giuoc River in Southern Vietnam

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    In this study, the variables of zooplankton and water quality were investigated in the Can Giuoc River, Southern Vietnam. Zooplankton was monitored in April and September 2015 at 5 sampling sites in the river. Some basic water quality parameters were also tested, including pH, total suspended solid (TSS), dissolved oxygen (DO), biological oxygen demand (BOD5), inorganic nitrogen (NH4+), dissolved phosphorus (PO43-), and coliform. The zooplankton biodiversity indices were applied for the water quality assessment. The results showed that pH ranged from 6.7 to 7.6 during the monitoring. The TSSs were between 34–117 mg/L. The DO and BOD5 were from 0.6 to 3.8 mg/L and from 6.3 to 13.2 mg/L, respectively. The NH4+ and PO43- concentrations ranged from 0.44 to 3.23 and from 0.08 to 1.85 mg/L, respectively. The coliform number was between 9.3x103–9.3x104 MPN/100 mL. The zooplankton analyses showed that there were 31 species of coelenterates, rotatoria, oligochaetes, cladocerans, copepods, ostracods, mysidacea, and 8 larval types. Thereof, the species of copepods were dominant in the species number. The zooplankton density ranged from 9 500 to 23 600 individuals/m3 with the main dominant species of Moina dubia (Cladocera), Thermocyclops hyalinus, Acartia clausi, Oithona similis (Copepoda), and nauplius copepods. The biodiversity index values during the monitoring were from 1.47 to 1.79 characteristic of mesotrophic conditions of the aquatic environment. Besides, the species richness positively correlated with pH, TSS, DO, BOD5, NH4+, PO43-, and coliform, while the zooplankton densities got a positive correlation with DO, BOD5, NH4+, PO43-, and coliform. The results confirmed the advantage of using zooplankton and its indices for water quality assessment

    The Influence Of Human Resource Policy On Job Satisfaction In Predicting Organizational Commitment

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    Purpose:  This research aims to explore the relationship among  human resource policy, job  satisfaction and  organizational commitment  through  the perception of employees working in small and medium enterprises in Vietnam.   Theoretical framework: The human resource functions and related distinct processes that help attract, develop, and retain a company's human resources. They involve employees and guide them to help carry out activities aimed at achieving organizational goals employees (Jahanian et al., 2012).  Business leaders are always cautious when reviewing existing human resource policies and constantly improving to make employees satisfied with their jobs, thereby helping them improve their productivity and commitment to the organization.    Design/methodology/approach:   The qualitative method is based on an overview of previous studies, the research team builds the first scale, then the questionnaire is sent to the experts and conducts a trial survey with 30 employees to control the survey, edit and complete the concepts of the questionnaire. For the quantitative research, data was collected using convenience sampling method from a total of 400 employees and managers who are working at SMEs in Viet Nam. The method of  and Confirmatory Factor Analysis (CFA),  Structural Equation Modeling (SEM) were carried out to measure the influence of latent variables on  organizational commitment.   Findings:  The research results show that employees' perceptions of HR policies include selection and recruitment; training and improvement; evaluation of employees’ tasks; stability and promotion in work, remuneration and reward, and encouragement of participation and innovation.  These HR policies have a direct positive impact on job satisfaction and commitment to the organization. In addition, job satisfaction has a significant positive effect on organizational commitment. Therefore, it is necessary to improve the implementation of HR policies to promote employee job satisfaction, which helps to increase commitment to the organization.    Research, Practical & Social implications:  We recommend future research that expands on other components for a comprehensive assessment of HR policies. In addition, it is necessary to analyze in detail the components of organizational commitment such as affective commitment,  Continuance commitment, Normative commitment.   Originality/value: The results of standardized estimation of the parameters of the research model show that the relationship between the concepts in the formal research model is statistically significant (p<0.05). HR policies have been shown to have the most positive impact on job satisfaction in SMEs.&nbsp

    The First Record of Metaphire Birmanica (Rosa, 1888) in Vietnam, with Notes on Several Earthworm Species

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    The Amynthas and Metaphire species recorded in Vietnam have been rechecked based on original descriptions and preserved specimens. As a result, Metaphire birmanica (Rosa, 1888) is recorded in Vietnam for the first time. The species is recognized by having three pairs of spermathecal pores in 5/6/7/8, male pores in xviii, presence of copulatory pouches, no genial markings, and manicate intestinal caeca. In addition, three species have been rechecked and re-assigned to different genera, namely Amynthas tripidoporophoratus (Thai & Nguyen, 1993) comb. nov., Metaphire dranfocana (Do & Huynh, 1993) comb. nov., Metaphire anhumalatana (Thai & Huynh, 1993) comb. nov
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