1,819 research outputs found

    A Broadband UHF Tag Antenna For Near-Field and Far-Field RFID Communications

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    The paper deals with the design of passive broadband tag antenna for Ultra-High Frequency (UHF) band. The antenna is intended for both near and far fields Radio Frequency Identification (RFID) applications. The meander dipole tag antenna geometry modification is designed for frequency bandwidth increasing. The measured bandwidth of the proposed broadband Tag antenna is more than 140 MHz (820–960 MHz), which can cover the entire UHF RFID band. A comparison between chip impedance of datasheet and the measured chip impedance has been used in our simulations. The proposed progressive meandered antenna structure, with an overall size of 77 mm × 14 mm × 0.787 mm, produces strong and uniform magnetic field distribution in the near-field zone. The antenna impedance is matched to common UHF chips in market simply by tuning its capacitive and inductive values since a perfect matching is required in the antenna design in order to enhance the near and the far field communications. Measurements confirm that the designed antenna exhibits good performance of Tag identification for both near-field and far-field UHF RFID applications

    Wear transitions in a wear coefficient model

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    The frictional-work wear model has been used popularly for the prediction of wear phenomena such as rail corrugation. The accuracy of such models depends on the value chosen for the empirical wear coefficient in this wear model. Experimental results have widely shown that this wear coefficient is strongly dependent upon the type of wear process involved. The wear coefficient in the frictional-work wear model under two-disc contact and dry friction conditions proposed is a multi-step function of the friction power density corresponding to three types of wear. However, at present there is no clear means of predicting the transitions between wear types. This paper investigates wear transitions between the wear types are predicted using analytical models based on the wear mechanics involved

    Cultural evolution in Vietnam’s early 20th century: a Bayesian networks analysis of Franco-Chinese house designs

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    The study of cultural evolution has taken on an increasingly interdisciplinary and diverse approach in explicating phenomena of cultural transmission and adoptions. Inspired by this computational movement, this study uses Bayesian networks analysis, combining both the frequentist and the Hamiltonian Markov chain Monte Carlo (MCMC) approach, to investigate the highly representative elements in the cultural evolution of a Vietnamese city’s architecture in the early 20th century. With a focus on the façade design of 68 old houses in Hanoi’s Old Quarter (based on 78 data lines extracted from 248 photos), the study argues that it is plausible to look at the aesthetics, architecture, and designs of the house façade to find traces of cultural evolution in Vietnam, which went through more than six decades of French colonization and centuries of sociocultural influence from China. The in-depth technical analysis, though refuting the presumed model on the probabilistic dependency among the variables, yields several results, the most notable of which is the strong influence of Buddhism over the decorations of the house façade. Particularly, in the top 5 networks with the best Bayesian Information Criterion (BIC) scores and p\u3c0.05, the variable for decorations (DC) always has a direct probabilistic dependency on the variable B for Buddhism. The paper then checks the robustness of these models using Hamiltonian MCMC method and find the posterior distributions of the models’ coefficients all satisfy the technical requirement. Finally, this study suggests integrating Bayesian statistics in the social sciences in general and for the study of cultural evolution and architectural transformation in particular

    The Mediating Effect Of Perceived Quality on The Customer Loyalty in Small And Medium-Sized Enterprises (SMEs) in The Mobile Phone Sector in Ho Chi Minh City (HCMC)- Vietnam

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    This paper is to analyze the relationship of branding on perceived quality of the service enterprises towards customer loyalty in marketing managementrsquos perspective in Vietnam particular in the retail market in a time of intense competition for the products or service supplied by the SMEs in the mobile sector. In the business organization, the primary target of enterprises is to convince customers to buy products or services in the long-term relationship. Nowadays, the most important issue for the business organization is to create an advantage of sustainable competition. In addition, brand is a vital asset of any business organization because it leads to the customerrsquos loyalty. Hence, the customer loyalty is the most important factor to enhance the competitive advantage in any enterprises. Besides, perceived quality of customers on their products or services when they purchase remains one of the most significant values in marketing management. There are two reasons why the perceived quality is important for the mediating role between in customers and branding firstly, the perceived quality determines the success or failure of business secondly, it influences the rate of acceptance of the products or service for the business organization. Therefore, this paper aimed to explore the mediating effect on customersrsquo perceived quality towards their loyalty the branding in the SMEs in the mobile sector. In the first stage, the study has applied the expertrsquos opinion to analyze the factors effect on the customerrsquos loyalty. In the second one, the researcher applied the qualitative method to interview around 10 buyers who regularly purchase in The Gioi Di Dongrsquos Shops and Vien Thong Arsquos Shops in Ho Chi Minh City (HCMC) with the convenient method to observe the process of service to get the close ideas of service to build the questions for the observed variables in the SMEs in mobile phone sector as well as enhance customersrsquo loyalty. In general, the author composed 5 factors including 34 observed variables from total of 50 observed variables chosen to build the questionnaire scale such as (1) Brand trust, (2) Service Organization, (3) Brand Awareness, (4) Perceived Quality, and (5) Customerrsquos Loyalty to study in Vietnamese SMEs in mobile phone sector in HCMC, Vietnam.nbsp nbsp nbsp nbsp nbsp nbsp nbsp nbspnbs

    Development and application of rice starch based edible coating to improve the postharvest storage potential and quality of plum fruit (<i>Prunus salicina</i>)

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    The study investigated the possibility of enhancing the shelf life of plum fruit coated with rice starch-ι-carrageenan (RS-ι-car) composite coating blended with sucrose fatty acid esters (FAEs). Film solution (starch 3%, carrageenan 1.5% and FAEs 2%) was prepared by mixing the ingredients and properties of stand-alone films (physical, mechanical, barrier and surface morphology) were studied before applying the coating on fruit surface. Fruit were stored at 20 °C for 3 weeks and analyzed for weight loss, ethylene production, respiration rate, color change, firmness, and titratable acidity (TA) and soluble solid content (SSC). Surface morphology of stand-alone film and fruit surface (after applying on the plum fruit) was studied using scanning electron microscopy (SEM). Phytochemical analysis was performed during the storage period and total phenolic content (TPC), total antioxidant capacity (TAC), flavonoid content (FC) and free radical scavenging activity were determined. The rice starch composite coating was shown to be effective in reducing both weight loss (WL) and respiration rate and inhibiting the endogenous ethylene production when compared to the uncoated control fruit stored at room temperature (p &lt; 0.05). TPC, TAC, FC and free radical scavenging activity was unaffected in the coated fruit throughout the storage period (p &lt; 0.05). The findings reported in this study indicate that the RS-ι-car-FAEs coating prolongs the shelf life and maintains the overall quality of plum fruit during storage and could potentially be commercialized as a new edible coating for the plum fruit industry

    A starch edible surface coating delays banana fruit ripening

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    A rice starch edible coating blended with sucrose esters was developed for controlling the postharvest physiological activity of Cavendish banana to extend postharvest quality during ripening at 20 ± 2 °C. Coating effectiveness was assessed against changes in fruit physiochemical parameters such as weight loss, titratable acidity, total soluble solids, flesh fruit firmness, ion leakage, colour change, respiration, ethylene production, chlorophyll degradation and starch conversion were determined. The topography of coating material on the fruit surface was evaluated by scanning electron microscope (SEM). Surface morphology studies highlighted the binding compatibility of the coating matrix with the fruit peel character and formed a continuous uniform layer over the fruit surface. The results showed that the coating was effective in delaying ethylene biosynthesis and reducing respiration rate. Other factors impacting included delayed chlorophyll degradation, reduced weight loss and retention of fruit firmness for the first six days, all of which improved the commercial value of the fruit. The shelf life of coated fruit was prolonged for 12 days in comparison with the untreated control which ripened within seven days and lost marketability after Day 6. The pilot study demonstrates the effectiveness of a starch-based edible coating formulation for improving the ambient storage capacity of banana fruit
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