696 research outputs found
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Querying Faceted Databases
Faceted classification allows one to model applications with complex classification hierarchies using orthogonal dimensions. Recent work has examined the use of faceted classification for browsing and search. In this paper, we go further by developing a general query language, called the entity algebra, for hierarchically classified data. The entity algebra is compositional, with query inputs and outputs being sets of entities. Our language has linear data complexity in terms of space and quadratic data complexity in terms of time. We compare the entity algebra with the relational algebra in terms of expressiveness. We also describe an implementation of the language in the context of two application domains, one for an archeological database, and another for a human anatomy database
Теренско истражување во Радовишко поле
Студентите од Факултетот за музичка уметност од Штип, катедрата по етнокореологија имаа прилика неколку дена да истражуваат во етничките предели Радовишко Поле и Радовишки Шоплук. Истажувањата се вршеа во неколку села и тоа: Ињево, Дедино, Ораовица, Козбунар, Јаргулица, Шаинташ, Ново село и тн. Тема на истаржувањата беа народните ора, народните песни, народните инструменти и народните носии. Собраните материјали депонирани се на факултетот и претставуваат база за понатамошни истражувања од областа на етнокореологијата
Primary energy savings using heat storage for biomass heating systems
District heating is an efficient way to provide heat to residential, tertiary and industrial users. The heat storage unit is an insulated water tank that absorbs surplus heat from the boiler. The stored heat in the heat storage unit makes it possible to heat even when the boiler is not working, thus increasing the heating efficiency. In order to save primary energy (fuel), the boiler operates on nominal load every time it is in operation (for the purpose of this research). The aim of this paper is to analyze the water temperature variation in the heat storage, depending on the heat load and the heat storage volume. Heat load is calculated for three reference days, with average daily temperatures from -5 to 5°C. The primary energy savings are also calculated for those days in the case of using heat storage in district heating.[Projekat Ministarstva nauke Republike Srbije, br. TR 33051: The concept of sustainable energy supply of settlements with energy efficient buildings
Nucleation activity of glass fibers towards iPP evaluated by DSC and polarizing light microscopy
Nucleation activity of unsized and differently sized glass fibers during the crystallization of polypropylene from melt was investigated by polarizing light microscopy and DSC. Depending on the type of surface treatment, glass fibers were shown to exhibit different nucleating effects, evaluated by induction time of crystallization, crystallization onset temperature as well as half-time of crystallization in model composites with 50% wt glass fibers. Predominant nucleation activity was found for glass fibers sized with polypropylene compatible dispersion containing polyurethanes. However, according to the results of DSC measurements, unsized glass fibers slightly depressed the nucleation of polypropylene. Using the approach of Dobreva et al., the activity of the fibers towards heterogeneous nucleation during nonisothermal crystallization was evaluated
Enzymes and wine – the enhanced quality and yield
Enzymes are a natural and fundamental element of the winemaking process. These enzymes originate from the grape, yeasts and other microbes associated with vineyards and wine cellars. Grape enzymes are however inactive under the pH and SO2 conditions associated with winemaking. Fungal pectinases are resistant to these winemaking conditions. The method used to produce wine enzymes for use in the EU is regulated by the Office International de la Vigne et du Vin (OIV). Nowadays, they are also a commercial product found in many wineries. The most widely used enzymes available for commercial use are: pectinases, hemicellulases, glycosidases and glucanases. From the pre-fermentation stage, through fermentation, post-fermentation and aging, enzymes catalyze various biotransformation reactions. In the past years, enzymes have been increasingly used for enhancing the quality of wines. They have the potential to make more extracted and more aromatic wines and to accelerate the winemaking process. This review summarizes the most important types of commercial enzymes applied to winemaking and their effects on the process technology and the quality of the final product
Apparel Industry in Macedonia, Conditions and Challenges
Around 395 registered companies in Macedonia work with apparel manufacturing. Even though they are spread across the whole country, the largest number of companies – 119 (or 30%) are located in the East region.
This industrial activity employs 31,742 employees or 6.1% of Macedonia’s working population. Compared to 2012, a 4.8% decrease is noted. The cumulative manufacturing index for 2014/2015 is 107, and the manufacturing index for 2015 (compared to 2010) is 136. Textile production participates with 11.7% in the total export of the country, and with 6.9% in the import.
The textile industry participates with 15.5% in the total gross domestic product, while in the industrial it participates with 21.8%. The textile industry participates in the total export with 26%, and employees 28% of the total number of employees in the industry. 93% of the apparel production is organized according to the CMT system for the foreign markets, mostly the European countries. The added value is low because 92-42% of the production is Lon, which brings small profits, even though the companies manufacture for quite famous worldwide brands.
Statistic data shows there is a necessity for changing the manufacturing structure towards products with higher added value, i.e. products for internal use. For this, hiring larger domestic capacities and resources is required
Solitary pulmonary amyloidoma mimicking lung cancer on 18F-FDG PET-CT scan in systemic lupus erythematosus patient
Localized amyloid deposits (tumoral amyloidosis or amyloidoma) are uncommon form of amyloidosis and nodular pulmonary amyloidomas are rarely found. This incidental finding can mimic a bronchopulmonary neoplasm and may occur secondarily to an infectious, inflammatory or lymphoproliferative disease. We report a case of a 62-year-old female with long-standing systemic lupus erythematosus (SLE) with low compliance who presented with radiologically-verified solitary pulmonary nodule. Work-up included positron emission tomography-computed tomography (PET-CT) scan, which revealed hypermetabolic uptake of (18)F-fluorodeoxyglucose, and lobectomy was performed. Staining of the tissue was positive for Congo red and was green birefringent under polarized light. Immunohistochemical methods excluded lymphoproliferative disease and confirmed amyloidoma. SLE was controlled with antimalarials and glucocorticoids. Pulmonary amyloidoma should be considered in the differential diagnosis of solitary lung nodules
Thermal mass impact on energy performance of a low, medium and heavy mass building in Belgrade
Heavy mass materials used in building structures and architecture can significantly affect building energy performance and occupant comfort. The purpose of this study was to investigate if thermal mass can improve the internal environment of a building, resulting in lower energy requirements from the mechanical systems. The study was focused on passive building energy performance and compared annual space heating and cooling energy requirements for an office building in Belgrade with several different applications of thermal mass. A three-dimensional building model was generated to represent a typical office building. Building shape, orientation, glazing to wall ratio, envelope insulation thickness, and indoor design conditions were held constant while location and thickness of building mass (concrete) was varied between cases in a series of energy simulations. The results were compared and discussed in terms of the building space heating and cooling energy and demand affected by thermal mass. The simulation results indicated that with addition of thermal mass to the building envelope and structure: 100% of all simulated cases experienced reduced annual space heating energy requirements, 67% of all simulated cases experienced reduced annual space cooling energy requirements, 83% of all simulated cases experienced reduced peak space heating demand and 50% of all simulated cases experienced reduced peak space cooling demand. The study demonstrated that there exists a potential for reducing space heating and cooling energy requirements with heavy mass construction in the analyzed climate region (Belgrade, Serbia)
Performance of Sensor Fusion for Vehicular Applications
Sensor fusion is a key system in Advanced Driver Assistance Systems, ADAS. The perfor-mance of the sensor fusion depends on many factors such as the sensors used, the kinematicmodel used in the Extended Kalman Filter, EKF, the motion of the vehicles, the type ofroad, the density of vehicles, and the gating methods. The interactions between parametersand the extent to which individual parameters contribute to the overall accuracy of a sensorfusion system can be difficult to assess.In this study, a full-factorial experimental evaluation of a sensor fusion system basedon a real vehicle was performed. The experimental results for different driving scenariosand parameters are discussed and the factors that make the most impact are identified.The performance of sensor fusion depends on many factors such as the sensors used, thekinematic model used in the Extended Kalman Filter (EKF) motion of the vehicles, type ofroad, density of vehicles, and gating methods.This study identified that the distance between the vehicles has the largest impact on theestimation error because the vision sensor performs poorly with increased distance. In addi-tion, it was identified that the kinematic models had no significant impact on the estimation.Last but not least, the ellipsoid gates performed better than rectangular gates.In addition, we propose a new gating algorithm called an angular gate. This algorithmis based on the observation that the data for each target lies in the direction of that target.Therefore, the angle and the range can be used for setting up a two-level gating approachthat is both more intuitive and computationally faster than ellipsoid gates. The angulargates can achieve a speedup factor of up to 2.27 compared to ellipsoid gates.Furthermore, we provide time complexity analysis of angular gates, ellipsoid gates, andrectangular gates demonstrating the theoretical reasons why angular gates perform better.Last, we evaluated the performance of the Munkres algorithm using a full factorial designand identified that narrower gates can speedup the running time of the Munkres algorithmand, surprisingly, even improve the RMSE in some cases.The low target maneuvering index of vehicular systems was identified as the reason whythe kinematic models do not have an impact on the estimation. This finding supports the useof simpler and computationally inexpensive filters instead of complex Interacting MultipleModel filters. The angular gates also improve the computational efficiency of the overallsensor fusion system making them suitable for vehicular application as well as for embeddedsystems and robotics
Systems with Session-based Workloads: Assessing Performance and Reliability
Many systems, including the Web and Software as a Service (SaaS), are best characterized with session-based workloads. Empirical studies have shown that Web session arrivals exhibit long range dependence and that the number of requests in a session is well modeled with skewed or heavy-tailed distributions. However, models that account for session workloads characterized by empirically observed phenomena and studies of their impact on performance and reliability metrics are lacking.;For assessing performance, we use a feedback queue to account for session-based workloads in a physically meaningful way and use simulation to analyze the behavior of the Web system under Long Range Dependent (LRD) session arrival process and skewed distribution for the number of requests in a session. Our results show that the percentage of dropped sessions, mean queue length, mean waiting time, and the useful server utilization are all affected by the LRD session arrivals and the statistics of the number of requests within a session. The impact is higher in the case of more prominent long-range dependence. Interestingly, both the request arrival process and the request departure process are long-range dependent, even in the case when session arrivals are Poisson. This indicates that the LRD at the request level can be a result of the existence of sessions.;For assessing reliability, we propose a framework which integrates (1) the Web workloads defined in term of user sessions, (2) the user navigation patterns through the Web site, and (3) the reliability estimates of the Web requests based on the system architecture; then, we give a detailed reliability model of a Web system based on the proposed framework. We recognize the difficulty of solving the proposed model and use simulation to obtain the results. And last but not least, we use statistical design of experiment to quantify the results and to determine which factors have the highest impact on the system\u27s reliability. Our results show that some two-way and three-way interactions are very important for the session reliability of Web systems
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