8,124 research outputs found
Effective Testing with JSFUnit for Educational Applications
AbstractSoftware testing is one of the steps of software quality assurance. Even testing is a crucial element in the software process, it can be seen by developers as âtime consumingâ or destructive instead of constructive work. However, it should be considered as a âmustâ of a project, in the case of taking failure rate of software projects into account. After the decision-making on following testing procedure, the first question that comes to mind is âHow do I test my application?â Java Server Faces (JSF) can offer a Java-based Web framework for educational applications. It assists to simplify development of web-based user interfaces. While doing testing for the applications utilizing JSF Framework, developers can use JSFUnit, which is a test framework allowing complete integration testing and unit testing.This paper focuses on sharing experiences with developers who intend to use JSFUnit for testing educational applications utilizing JSF Framework
I Read I Play: A Web Based Application for Supporting Children's Learning Process
AbstractIn latest years, there is a consisting trend in creating increasingly rich educational opportunities involving for children. Epistemology and technology act for an important set to determine innovative educational materials. Computers can engender a bridge over the educational distances for every child. Realizing a demand, a Web-based application has been developed with a creative reading approach in order to improve the child's reading-comprehension, narrative skills involving activities such as reading, writing, visual reading, relating, comprehension, criticizing, estimation and playing educational computer games. This study aims to offer to children many learning benefits such as motivation, engagement and fun in addition to providing many skills for instance logical thinking and problem solving as well as understanding of abstract concepts. This paper focuses on sharing implementation experiences of our application that expand a positive attitude for reading in children
A Parallel Implementation of Unscheduled Flow Control in Interconnected Power Systems
The unscheduled power flow problem needs to be minimized or controlled as soon as possible in a deregulated power system since the transmission systems are mostly operated at their power-carrying limits or very close to it. The time spent for simulations to determine the current states of all the system and control variables of the interconnected power system is important. Taking necessary action in case of any failure of equipment or any other occurrence of an undesired situation could be critical. Using supercomputing facilities and parallel computing techniques together decreases the computation time greatly. In this study, a parallel implementation of a multiobjective optimization approach based on both genetic algorithms and fuzzy decision making to manage unscheduled flows is presented. Parallel computation techniques are applied using supercomputers (high-performance computers). The proposed method is applied to the IEEE 300 bus test system. Two different cases for some parameters of GA are considered to see the power of parallel computation technique. Then the simulation results are presented
Strategic Generation Capacity Choice under Demand Uncertainty:Analysis of Nash Equilibria in Electricity Markets
Abstract: We analyze a two-stage game of strategic firms facing uncertain demand and exerting market power in decentralized electricity markets. These firms choose their generation capacities at the first stage while anticipating a perfectly competitive future electricity spot market outcome at the second stage; thus it is a closed loop game. In general, such games can be formulated as an equilibrium problem with equilibrium constraints (EPEC) and examples have been posed in the literature that have multiple or no equilibria. Therefore, it is of interest to define general sets of conditions under which solutions exist and are unique, which would enhance the value of such models for policy andmarket intelligence purposes. In this paper, we consider various types of such a closed loop model regarding the underlying price-demand relations (elastic and inelastic demand), the assumed demand uncertainty with a broad class of continuous distributions, and any finite number of players with symmetric or asymmetric costs. We establish sufficient conditions for the random demandâs probability distribution which guarantee existence and uniqueness of equilibria in most of the cases of this closed loop model. We identify a broad class of commonly used continuous probability distributions satisfying these conditions
Validation of microsatellite markers for cytotype discrimination in the model grass Brachypodium distachyon
Brachypodium distachyon (2n = 2x = 10) is a small annual grass species where the existence of three different cytotypes (10, 20 and 30 chromosomes) has long been regarded as a case of autopolyploid series, with x = 5. However, it has been demonstrated that the cytotypes assumed to be polyploids represent two separate Brachypodium species recently named as B. stacei (2n = 2x = 20) and B. hybridum (2n = 4x = 30). The aim of this study was to find a PCR-based alternative approach that could replace standard cytotyping methods (i. e., chromosome counting and flow cytometry) to characterize each of the three Brachypodium species. We have analyzed with four microsatellite (SSR) markers eighty-three Brachypodium distachyon-type lines from varied locations in Spain, including the Balearic and Canary Islands. Within this set of lines, 64, 4 and 15 had 10, 20 and 30 chromosomes, respectively. The surveyed markers produced cytotype-specific SSR profiles. So, a single amplification product was generated in the diploid samples, with non-overlapping allelic ranges between the 2n = 10 and 2n = 20 cytotypes, whereas two bands, one in the size range of each of the diploid cytotypes, were amplified in the 2n = 30 lines. Furthermore, the remarkable size difference obtained with the SSR ALB165 allowed the identification of the Brachypodium species by simple agarose gel electrophoresis
Generation Capacity Investments in Electricity Markets:Perfect Competition
Abstract: In competitive electricity markets, markets designs based on power exchanges where supply bidding (barring demand-side bidding) is at the sole short run marginal cost may not guarantee resource adequacy. As alternative ways to remedy the resource adequacy problem, we focus on three different market designs in detail when demand is inelastic, namely an energy-only market with VOLL pricing (or a price cap), an additional capacity market, and operating-reserve pricing. We also discuss demand-side bidding (i.e., a price responsive demand) which can be seen as a categorically different alternative to remedy the resource adequacy problem. We consider a perfectly competitive market consisting of three types of agents: generators, a transmission system operator, and consumers; all agents are assumed to have no market power. For each market design, we model and analyze capacity investment choices of firms using a two-stage game where generation capacities are installed in the first stage and generation takes place in future spot markets at the second stage. When future spot market conditions are assumed to be known a priori (i.e., deterministic demand case), we show that all of these two-stage models with different market mechanisms, except operating-reserve pricing, can be cast as single optimization problems. When future spot market conditions are not known in advance (i.e., under demand uncertainty), we essentially have a two-stage stochastic game. Interestingly, an equilibrium point of this stochastic game can be found by solving a two-stage stochastic program, in case of all of the market mechanisms except operating-reserve pricing. In case of operatingreserve pricing, while the formulation of an equivalent deterministic or stochastic optimization problem is possible when operating-reserves are based on observed demand, this simplicity is lost when operatingreserves are based on installed capacities. We generalize these results for other uncertain parameters in spot markets such as fuel costs and transmission capacities. Finally, we illustrate how all these models can be numerically tackled and present numerical experiments. In our numerical experiments, we observe that uncertainty of demand leads to higher total generation capacity expansion and a broader mix of technologies compared to the investment decisions assuming average demand levels. Furthermore for the same VOLL (or price cap) level and under the assumptions of random demand with finite support and no forced outages, energy-onlymarkets with VOLL pricing tend to lead to total generation capacity below the peak load with a certain probability whereas energy markets with a forward capacity market or operating-reserve pricing result in higher investments. Finally, the regulator decisions (e.g., reserve capacity target) in capacity markets and operating-reserve pricing can be chosen in such a way that results in very similar investment levels and fuel mix of generation capacities in b
The effects of different nitrogen doses on yield, quality and leaf nitrogen content of some early grape cultivars (V. vinifera L.) grown in greenhouse
Nitrogen deficiency is a worldwide problem, causing restrictions in productivity of many horticultural produces. Particularly, the issue is compounded when the greenhouse production is employed. Therefore, reliable knowledge on proper application of nitrogen ensures not only satisfactory yield but also balanced vegetative and reproductive growth in plants. This study was thus conducted to investigate the effects of different nitrogen doses (10, 20 and 30 kg N da-1) on some quality properties with petiole nitrogen content of grape cultivars âEarly Cardinalâ (EC), âYalova Incisiâ (YI) and âErgin Cekirdeksiziâ (ER) grown in plastic greenhouse for two years. Overall results indicated that cluster weight, cluster length and yield values increased depending on the nitrogen doses. On the other hand, increasing nitrogen applications generally resulted in higher petiole nitrogen content. The highest petiole nitrogen values were obtained from the treatment of 30 kg N da-1 for two phenologycal periods (1.29 and 1.59% for full bloom and veraison, respectively). Considering the general investigations, 20 kg N da-1 application could be recommended in terms of nitrogen supply under such conditions.Key words: Grapevine, nitrogen fertilizing, yield, petiole analysis
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