Study of structural,electrical and optical properties of vanadium oxide condensed films deposited by spray pyrolysis technique

Vanadium oxides condensed films are prepared on glass substrates, using spray pyrolysis (SP) technique.The effects of substrate temperature, vanadium concentration in initial solution and the solution spray rate on the nano-structural, electrical, and optical properties of deposited films were investigated. Characterizations of the samples were performed using X-ray diffraction (XRD),scanning electron microscopy (SEM), and UV-Vis spectroscopy methods. The type and concentration of the charge carriers were determined and measured by Hall effect experiment. XRD patterns showed that the prepared films had polycrystalline structure, mostly tetragonal β-V₂O₅ and V₄O₉ phases with the preferred orientation along (200) direction. The Hall effect experiment revealed that all samples were n-type, except the ones deposited at substrate temperatures Tsub = 300 ℃ and Tsub = 450 ℃, vanadium concentration 0.1 mol/L and solution spray rate 10 mL/min.The charge carrier concentrations obtained were in the range 10¹⁶–10¹⁸ cm^-3. The lowest sheet resistance (R_s) was obtained for the samples prepared at T_sub = 450 ℃, vanadium concentration 0.05 mol/L and solution spray rate 10 mL/min. It was also found that the optical transparency of the samples changed from 20% to 75% and the optical band gap of the samples was from 2.22 eV to 2.58 eV, depending on the deposition conditions.     

Microwave-assisted rapid synthesis of alumina nanoparticles using tea,coffee and triphala extracts

Alumina nanoparticles (AlNP) were synthesized from aluminium nitrate using extracts of tea, coffee and triphala—a well known herbal plant as well as a nontoxic and eco—friendly green material. The synthesis was carried out taking 1:4 ratio of metal salt and these extracts under microwave irradiations at 540 W, which gave better yield of nanoparticles. Water was taken as solvent medium. The formations of AlNP were initially monitored by the colour changes occurring in the reaction mixture during the incubation period. As synthesized nanoparticles were characterized by scanning electron microscope (SEM),
UV–Visible (UV–Vis) spectroscopy and Fourier transform infrared spectroscopy (FTIR). The AlNP were found to be spherical in shape in case of tea and coffee extracts with a size of 50–200 nm and to be oval shaped in case of triphala extract with an average size of 200–400 nm. The formation of AlNP with the microwave-assistance using these plant extracts has proved to be very faster than any other methods. In addition, excellent reproducibility of these nanoparticles, without the use of any additional capping agent or stabilizer will have great advantages in comparison with microbial synthesis, avoiding all the tedious and hygienic complications.     

Optimal machining conditions for turning Ti-6Al-4V using response surface methodology

Machining titanium is one of ever-increasing magnitude problems due to its characteristics such as low thermal conductivity, modulus of elasticity and work
hardening. The efficient titanium alloy machining involves a proper selection of process parameters to minimize the tangential force (F_z) and surface roughness (R_a). In the present work, the performance of PVD/TiAlN coated carbide inserts was investigated using response surface methodology (RSM) for turning Ti-6Al-4V. The effects of process parameters such as speed (v), feed (f), depth of cut (d) and back rake angle (γ_y) on F_z and R_a were investigated.
The experimental plan used for four factors and three levels was designed based on face centered, central composite design (CCD). The experimental results indicated that F_z increased with the increase in d, f and decreased with the increase in v and γ_y, whereas Ra decreased with the increase in v and γ_y, and increased with d and v. The goodness of fit of the regression equations and model fits (R ²) for F_z and R_a were found to be 0.968 and 0.970, which demonstrated that it was an effective model. A confirmation test was also conducted in order to verify the correctness of the model.     

Implications of automation in engineer-to-order production:a case study

In order to retain a certain level of production in Norway,suppliers to the Norwegian maritime industry need to lower their production costs.Automation is generally an effective way of achieving this in standardized high-volume,low variety production.However,manufacturing companies in the Norwegian maritime industry typically supply capital-intensive,advanced and customized products in low volumes.In this engineer-to-order production situation,manual labor is traditionally preferred over automation.Nonetheless,such companies increasingly automate parts of their production.This paper presents a case of a supplier that has chosen to automate its welding operations,the implications and determinants of this decision.     

Approaching lean product development using system dynamics:investigating front-load effects

Competing with successful products has become perplexing with several uncertainties and transmutes from time to time as customers’ expectations are
dynamic. That is why manufacturing firms exhaustively strive to look for a better competitive frontier using wellestablished and innovative product development (PD) processes. In this paper, we would like to answer three research questions: (i) What would be the effects of frontloading
in PD? (ii) Can we improve our PD process endlessly? (iii) When is the critical time that the firm should take remedial action for improvements? As a contribution to the vast numbers of improvement methods in new product development (NPD), this paper investigates the effects of front-loading using set-based concurrent engineering (SBCE) on cost and lead time. Models are developed and treated using a system dynamics (SD) approach. We assign a hypothetical upfront investment for SBCE and compare its effects on  total cost and lead time of the development process. From the research, it is found that the total cost of PD is reduced almost by half-although the front loading is higher in order to encompass multiple design alternatives. The total product lead time is reduced by almost 20 %. The model reveals the critical time for improvement of the PD process. We use SD tool (e.g., STELLA) for simulation and visualization of the complex PD model, using SBCE as one of several strategies to frontload activities in the NPD process.     

The dynamic of professional knowledge utilized in software applications for process controlling

Main objective of the presented paper is the examination of the professional knowledge used in intelligent software applications for process controlling.It concerns in particular the user instruction and the realization of corresponding interaction as well as the interface design.Regular approach for service of the different user groups is evaluated and extended in means of flexibility in the time.The rules decisive for the user interaction with the application are outlined.They represent the interdependency between quality of professional knowledge to be utilized and user group characteristics alter in time.An application scenario for knowledge visualization is presented to show the practicability of the concept developed.     

Kinematic analysis and simulation of a new-type robot with special structure

Common methods,such as Denavit-Hartenberg(D-H) method,cannot be simply used in kinematic analysis of special robots with hybrid hinge as it is difficult to obtain the main parameters of this method.Hence,a homogeneous transformation theory is presented to solve this problem.Firstly,the kinematics characteristic of this special structure is analyzed on the basis of the closed-chain theory.In such a theory,closed chains can be transformed to open chains,which makes it easier to analyze this structure.Thus,it will become much easier to establish kinematics equations and get the solutions.Then,the robot model can be built in the Simmechanics(a tool box of MATLAB) with these equation solutions.It is necessary to design a graphical user interface(GUI) for robot simulation.After that,the model robot and real robot will respectively move to some spatial points under the same circumstances.At last,all data of kinematic analysis will be verified based on comparison between data got from simulation and real robot.     

Experimental investigation on the effects of process parameters of GMAW and transient thermal analysis of AISI321 steel

Gas metal arc welding (GMAW) develops an arc by controlling the metal from the wire rod and the input process parameters. The deposited metal forms a weld bead and themechanical properties depend upon the quality of the weld bead. Proper control of the process parameters which affect the bead geometry, the microstructures of the weldments and the mechanical properties like hardness, is necessary. This experimental study aims at developing mathematical models for bead height (HB), bead width (WB) and bead penetration (PB) and investigating the effects of four process parameters
viz: welding voltage, welding speed, wire feed rate and gas flow rate on bead geometry, hardness and microstructure of AISI321 steel with 10 mm thickness. The transient thermal analysis shows temperature and residual stress distributions at different conduction and convection conditions.     

Current status,enablersand barriers of implementing cellular manufacturing system in Indian industries

The cellular manufacturing (CM) has been proved as a well-known manufacturing strategy that helps to improve manufacturing efficiency and productivity by
utilizing the philosophy of group technology. Large number of papers has been published in the area of design issues of CM system. Unfortunately, the issues related to acceptability of CM in Indian industries are typically not examined rigorously as technical issues. This paper presents the results of a survey carried out to find the status, enabler and barrier of implementing CM system in Indian industries.     

Product portfolio map:a visual tool for supporting product variant discovery and structuring

A fundamental criterion for reusing and continuously improving knowledge in product development is ensuring that the knowledge is explicit and visual.This paper is based on the situation of an engineer-to-order(ETO) manufacturing company,where historically grown product variety and related knowledge are diffuse(tacit).Consequently,several resources are used in(re)developing derivatives of previous products rather than innovating new ones.To establish a more competitive configure-to-order(CTO) product strategy,product knowledge needs to be revealed,systemized,and structured,and thus made explicit.Hence,product-specific knowledge and product variants have been analyzed and subsequently mapped at architectural,functional,and physical levels in one unified map and tested in the form of a proof-of-concept(POC)demonstrator with the introduced SME company.The result is a product portfolio map that forms a base for defining a systemized,transparent,unified product variant overview,which can be used as a basis for implementing a cross-variant product architecture and supporting knowledge-based approaches.     

通胀风险下基于相对业绩的资产管理人的最优投资

研究了资产管理人在考虑通胀风险和激励机制下的最优投资问题。考虑一个含通胀风险的连续时间模型的金融市场,资产管理人可投资于通胀指数债券、股票和无风险债券这三类资产。假设用相对业绩来评估资产管理人的业绩,其薪酬设为相对业绩的非线性函数。利用凹化技术和鞅方法得到了看涨期权型和看跌–看涨期权型两种不同方案下的最优相对业绩和最优投资策略的解析表达式,进一步对通胀风险和两种绩效机制下的模型参数对最优投资策略的影响进行了敏感性分析。发现通胀指数债券能够帮助投资人有效地对冲通胀风险,并且看涨–看跌期权型薪酬方案能改善经济不景气时的风险管理。     

A framework for ICT-enabled real-time production planning and control

This paper aims to develop a conceptual framework for real-time production planning and control(PPC).Firstly,we discuss the most prominently applied contemporary information and communication technologies for PPC.Enterprise resource planning(ERP) systems that integrate the value chain in an enterprise,manufacturing execution systems that manage and control the production on shopfloor,and advanced planning and scheduling(APS)systems that develop solutions for complex planning problems are the planning and control systems that have been analyzed.We emphasize the application of radio frequency identification as the most advanced and promising emerging real-time data capture technology that is currently available to manufacturers.Having analyzed the features and shortcomings of the individual systems perse,and by considering the advantages that may be realized through effective integration of these otherwise discrete systems,we propose a framework for real-time PPC.     

Influence of defect density on the ZnO nanostructures of dye-sensitized solar cells

The relationship between bilayer nanostructure,defect density and dye-sensitized solar cell (DSCC) performances was investigated. By adjusting bilayer nanostructures,defect density of ZnO nanodendrite-nanorods structure was decreased comparing to that of nanoflowernanorods structure. The performances of DSCC based on ZnO nanodendrites-nanorods structure and nanoflowernanorods structure were studied by Raman spectrum, room
temperature photoluminescence, dye loading, photocurrent density-voltage characteristic and open-circuit voltage decay (OCVD) technique. The device with nanodendritenanorods structure has lower charge recombination rate and prolonged electron lifetime due to its microstructure feature.     

Numerical simulation of unsteady cavitating flows using a homogenous equilibrium model

 Numerical simulations of two-dimensional cavity flows around a flat plate normal to flow and flows through a 90^∘ bent duct are performed to clarify unsteady behavior under various cavitation conditions. A numerical method applying a TVD-MacCormack scheme with a cavitation model based on a homogenous equilibrium model of compressible gas-liquid two-phase media proposed by the present authors, is applied to solve the cavitating flow. This method permits the simple treatment of the whole gas-liquid two-phase flow field including wave propagation and large interface deformation. Numerical results including detailed observations of unsteady cavity flows and comparisons of predicted results with experimental data are provided. Received: 5 August 2002 / Accepted: 6 January 2003     

Integrated color defect detection method for polysilicon wafers using machine vision

For the typical color defects of polysilicon wafers,i.e.,edge discoloration,color inaccuracy and color non-uniformity,a new integrated machine vision detection method is proposed based on an HSV color model.By transforming RGB image into three-channel HSV images,the HSV model can efficiently reduce the disturbances of complex wafer textures.A fuzzy color clustering method is used to detect edge discoloration by defining membership function for each channel image.The mean-value classifying method and region growing method are used to identify the other two defects,respectively.A vision detection system is developed and applied in the production of polysilicon wafers.     

建设工程项目激励模型中的激励失效问题优化研究

分析表明,以往有关声誉协同激励的探讨常常会引发激励失效的问题,有以下表现：仅仅分析声誉一个因素的模型,容易产生激励失衡;但忽视声誉,只对各要素的协同性进行探讨的激励模型,则会发生激励过剩的情况。基于此,本文综合工期、质量之间的替代性特点,站在业主角度建立结合显性、隐性声誉的两阶段动态激励模型,有效防止激励失效问题的发生,进而提出使模型发挥作用的有效区间的判断方法。最后,文章采用算例及数据模拟的方式,对以上结论作出了证明。     

Fair incentive mechanism with pyramidal structure for peer-to-peer networks

Free-riding is a grave threat against the existence and efficient operation of peer-to-peer networks. This study proposes a rank-based fair incentive mechanism to restrain free-riding and solve the problem of the tragedy of the commons. In this mechanism, each user has a rank according to its utility value and it can just visit the corresponding rating files with its rank in the system. The utility function in this study takes the absolute contribution value and the physical performance into account for fairness and their values are calculated by the analytic hierarchy process. Besides, a pyramidal rank structure is constructed in this mechanism, and the computation formula for the node?s transfer in each layer is established. In addition, the four defects in other restrain mechanisms are resolved in this incentive mechanism. The simulations in three aspects have verified that this mechanism is effective and practical.     

基于储运单元的航材携行组配研究

目的 为有效提高航材保障应急准备和战时快速保障能力,探索基于储运单元的航材携行组配新模式,解决组配航材需求大与库存条件有限的矛盾问题。方法 科学设计模块化航材携行组配方案,以组配航材需求最少为目标,分别构建了绝对约束和宽松约束条件下的组配模块配置优化模型,并通过Matlab软件实现模型求解自动化。同时,引入模块配置允许偏差约束条件,以灵敏度分析为方法手段,合理调整组配方案中与库存条件不相适应的部分。结果 算例分析表明,模块化航材携行组配方案能够使组配规模和器材需求降低58.9%,可行性大幅提高,文中构建的模块配置优化模型既能够严格按照航材携行标准精确组配,又能够根据现实状况灵活应变,具有较强的实用性、适应性。结论 航材携行组配模块配置优化模型能够支持组配方案的实施,对航材携行组配模式研究的推进、提高航材保障机动性,具有重要的现实意义。     

Real option-based optimization for financial incentive allocation in infrastructure projects under public–private partnerships

Financial incentives that stimulate energy investments under public–private partnerships are considered scarce public resources, which require deliberate allocation to the most economically justified projects to maximize the social benefits. This study aims to solve the financial incentive allocation problem through a real option-based nonlinear integer programming approach. Real option theory is leveraged to determine the optimal timing and the corresponding option value of providing financial incentives. The ambiguity in the evolution of social benefits, the decision-maker’s attitude toward ambiguity, and the uncertainty in social benefits and incentive costs are all considered. Incentives are offered to the project portfolio that generates the maximum total option value. The project portfolio selection is formulated as a stochastic knapsack problem with random option values in the objective function and random incentive costs in the probabilistic budget constraint. The linear probabilistic budget constraint is subsequently transformed into a nonlinear deterministic one. Finally, the integer non-linear programming problem is solved, and the optimality gap is computed to assess the quality of the optimal solution. A case study is presented to illustrate how the limited financial incentives can be optimally allocated under uncertainty and ambiguity, which demonstrates the efficacy of the proposed method.