X-RAY PHOTOELECTRON SPECTROSCOPIC STUDY ON HIGH-ELECTRON-MOBILITY GALLIUM AND HYDROGEN CO-DOPED ZINC OXIDE THIN FILMS

In this study, gallium and hydrogen co-doped ZnO (HGZO) thin films were investigated. The films were deposited by sputtering from Ga-doped ZnO (GZO) ceramic target in hydrogen and argon plasma. The as-deposited HGZO films possess enhanced electron mobility of 48.6 cm2/Vs as compared to that of 39.4 cm2/Vs of GZO films, sputtered from the same target. Because of insignificant variation in crystallinity, this improvement is attributed to roles of hydrogen in crystalline lattice structure of the films. X-ray photoelectron spectroscopy (XPS) is employed as an essential technique for quantitative analyses and chemical binding states of films constituent elements. The roles of hydrogen are clarified through the binding states of Zn 2p, O 1s and Ga 3d. Obtained results suggest that the films are deposited more effectively in hydrogen plasma. Some point defects such as oxygen vacancies (VO), dangling bonds can be passivated in form of H+VOHO and O–H bonds. As a result, the reduction of scattering centers is indicated as a reason for the mobility improvement of the HGZO films

Is Nonfarm Diversification a Way Out of Poverty for Rural Households? Evidence from Vietnam in 1993-2006

school. Using the four high quality household living standards surveys available to date this paper reveals that Vietnam’s rural labour force has been markedly diversifying toward nonfarm activities in the doi moi (renovation) reform period. The employment share of the rural nonfarm sector has increased from 23 percent to 58 percent between the years 1993 and 2006. At the individual level, the results indicate that participation in the rural nonfarm sector is determined by a set of individual-, household-, and community-level characteristics. Gender, ethnicity, and education are reported as main individual-level drivers of nonfarm diversification. Lands as most important physical assets of rural households are found to be negative to nonfarm employment. It is also evident that both physical and institutional infrastructure exert important influences on individual participation in the nonfarm sector. At the household level, a combination of parametric and semi-parametric analysis is adopted to examine whether nonfarm diversification is a poverty exit path for rural households. This paper demonstrates a positive effect of nonfarm diversification on household welfare and this effect is robust to different estimation techniques, measures of nonfarm diversification, and the usage of equivalent scales. However, the poor is reported to benefit less than the non-poor from nonfarm activities. Though promoting a buoyant nonfarm sector is crucial for rural development and poverty reduction, it needs to be associated with enhancing access to nonfarm opportunities for the poor.Rural nonfarm sector, nonfarm diversification, household welfare, Vietnam

Parameter Estimation and Predictive Speed Control of Chopper-Fed Brushed DC Motors

This paper presents an effective speed control method for brushed DC motors fed by a DC chopper using the concept of Finite Control Set-Model Predictive Control (FCS-MPC). As this control algorithm requires the parameters of the controlled object, the estimation of motor parameters is first performed by using two types of data. The first data includes the output speed response corresponding to the step input voltage to obtain the transfer function in the no-load regime. The second data consists of the motor speed and armature current when a load torque is applied to the motor shaft. The discrete-time equation of the motor armature circuit is used to obtain the future values of the armature circuit current and the motor speed. A cost function is defined based on the difference between the reference and predicted motor speed. The optimal switching states of the DC chopper are selected corresponding to the maximum value of the cost function. The performance of the proposed speed control algorithm is validated on an experimental system. The simulation and experimental results obtained show that the MPC controller can outperform the conventional proportional-integral (PI) controller

A Rule-Based Language for Integrating Business Processes and Business Rules

International audienceBusiness process modeling has become a popular method for improving organizational efficiency and quality. Automatic validation of process models is one of the most valuable features of modeling tools, in face of the increasing complexity of enterprise business processes and the richness of modeling languages. This paper proposes a formal language, Event-Condition-Action-Event (ECAE), for integrating Colored Petri Nets (CPN)-based business process with a set of business rules. We automate the integration process for validating the business process model. The ECAE language has several important features: its reasoning capabilities, its ability to express complex actions and events, and its declarative semantics. By enabling simulation of business process behavior, the reasoning capabilities facilitate the early detection of flaws The widespread use of business process modeling has helped enterprises to design, control and analyze many operational processes. Unfortunately, syntactic and semantic inconsistencies often appear in business process models, especially as the complexity of the models increases. Flaw detection and automation are essential for ensuring cost-effective and correct process models. The challenge for system designers is to build a flexible intelligent system, which accepts and verifies the change on business process and business rules automatically. The business process must be integrated with a set of business rules, and a correspondence between the process and the rules must be created. This must be flexible since the business process and the business rules may be modified during runtime. The verification should be a rule-based system, which can reason and deduce new knowledge or a new decision based on a set of rules and facts. This paper proposes a formal language ECAE for business process modeling, which takes advantage of both the graphical representation of colored Petri nets and the easy to represent ECA rule. It designs a business process model through CPN and translate

STUDY ON FLUORINATION AND HYDROGENATION IN TRANSPARENT CONDUCTING ZINC OXIDE THIN FILMS

Fluorination and hydrogenation are known as two methods for enhancing crystalline structural and electrical properties of ZnO material. The ZnO thin films normally require a low resistivity and a high transmittance for using as high-performance transparent electrodes in optoelectronic applications. In this study, we report successful preparation of fluorinated and hydrogenated ZnO thin films (FZO and HFZO) by using d.c. magnetron sputtering technique. The hydrogenation was carried out by depositing the films in hydrogen plasma atmosphere, while a highly-sintered body of ZnO and ZnF2 compound was employed as a sputtering target for the fluorination. The results show that the strong improvements in carrier concentration, mobility and resistivity of the FZO and HFZO films as compared to the pure ZnO films. The carrier concentration increases to 2x1020 cm-3 which is mainly due to the hydrogenation. The effect combination of the fluorination and the hydrogenation is responsibility for enhancing the mobility up to 43 cm2/Vs. These results give rise to two-order reduction in resistivity, from 0.06 Ohm.cm (ZnO) to 7.5x10-4 Ohm.cm (HFZO), which can be a good choice for thin-film electrode application. In addition, the crystalline structure and optical transmission of the films are also discussed

Data-Driven Construction Safety Information Sharing System Based on Linked Data, Ontologies, and Knowledge Graph Technologies

Accident, injury, and fatality rates remain disproportionately high in the construction industry. Information from past mishaps provides an opportunity to acquire insights, gather lessons learned, and systematically improve safety outcomes. Advances in data science and industry 4.0 present new unprecedented opportunities for the industry to leverage, share, and reuse safety information more efficiently. However, potential benefits of information sharing are missed due to accident data being inconsistently formatted, non-machine-readable, and inaccessible. Hence, learning opportunities and insights cannot be captured and disseminated to proactively prevent accidents. To address these issues, a novel information sharing system is proposed utilizing linked data, ontologies, and knowledge graph technologies. An ontological approach is developed to semantically model safety information and formalize knowledge pertaining to accident cases. A multi-algorithmic approach is developed for automatically processing and converting accident case data to a resource description framework (RDF), and the SPARQL protocol is deployed to enable query functionalities. Trials and test scenarios utilizing a dataset of 200 real accident cases confirm the effectiveness and efficiency of the system in improving information access, retrieval, and reusability. The proposed development facilitates a new “open” information sharing paradigm with major implications for industry 4.0 and data-driven applications in construction safety management

Ontology-Based Workflow Validation

International audienceIn order to ensure a workflow to be executed correctly, many approaches were introduced. But not many of them consider the semantic correctness of the workflow in the design time and the run time. In this paper, a solution to check the semantic correctness of the workflow automatically is presented. To do that, the workflow must be represented in a machine understandable form, an ontology-based approach to represent a workflow is proposed. In addition, we also provide a set of changed operations allowing the users to customize a workflow for using in their organizations. Their change can be made while ensuring the correctness of the workflow. Moreover, a verification method is proposed for checking the semantic correctness of workflow

Development of Spray Pyrolysis System for Deposition of Nano-structure Materials

In this paper, we report the development of the spray pyrolysis technique for preparing different nano-structure materials toward the application in thin film solar cells. The spray pyrolysis system can heat up the substrate to 6000C with less than 0.01% full scale. The ramping rate can be set to 100C per minute. The effective coating area can be up to 100 x 100 mm2. Using this technique, the thickness and roughness of the films can be controlled. The obtained morphology, the microstructure of the thin-films, given by scanning electron microscope, X ray diffraction…showed that the system is suitable for deposition of different layers of the dye sensitized solar cell

Cost optimization of two-stage helical gearboxes with second stage double gear-sets

In practice, the cost of a gearbox plays a very important role in the trade. Therefore, reducing the cost of gearboxes is an important task not only when manufacturing the gearboxes but also when designing them. In order to reduce the cost of a gearbox, there are many solutions in which determining the optimal partial gear ratios of a gearbox is an effective measure. This is because it not only the size, the mass but also the cost of a gearbox depends greatly on the partial gear ratios. This work presents a method for calculating the cost function of two-stage helical gearboxes with second-stage double gear-sets based on the mass of the components that construct the gearbox. The cost objective function is minimized to achieve the optimal transmission ratios. Furthermore, screening experiments are carried out with nine important input parameters that have significant effects on the optimum transmission ratio of the second stage. These parameters are the total gearbox ratio, the coefficient of wheel face width of the first stage, coefficient of wheel face width of the second stage, the allowable contact stress of the first stage, the allowable contact stress of the second stage, the output torque, the cost of gearbox housing, the cost of gears, and the shaft cost. The experimental results of were analysed by using the Analysis of Variance (ANOVA) method with the help of Minitab 19 software. The results demonstrate that the effective weight of the input parameters and their interactions on the output response was investigated. Also, a regression model for computing the optimal transmission ratio of the second stage was proposed. This brings significance not only in the design process but also in manufacturing since the gearbox cost can decreas