Most of the generated electricity in Kosovo is produced from fossil fuel, a part of the energy comes from the import, while participation of renewable resources is symbolic, and a bias between the grid extension and the load of power generated sometimes results in shortage of electricity and thus frequent power cuts. The use of renewable energy and particularly the solar thermal energy represents one of the most promising alternative strategies. In Kosovo, the global horizontal radiation ranges from 1241 kWh/m2 per year in Shterpce to 1461 kWh/m2 per year in Gjakova, while the average for Kosovo can be estimated at 1351 kWh/m2 per year. The average sun duration for the city of Pristine is 5.44 h, while the average horizontal irradiation is 3.79 kWh/m² per day. Participation of energy consumption in household is still dominant - about 41.4% of the total consumption in Kosovo, 15% of this energy is used for domestic hot water. This energy demand can be lowered significantly by using improved building construction techniques and utilization of RES-s, especially solar thermal. The first step is to map the city in different areas to locate suitable locations for the installation of solar collectors serving sanitary hot water. The demand for sanitary hot water varies from object to object, this variation depends on whether the building is individual or collective, school institutions or religious buildings, for this reason the classification of buildings was done according to the request for sanitary hot water. After that the demand for sanitary hot water is calculated for several different institutions: Residential houses, Dormitories and Hospitals. For all of the above-mentioned cases the data for: solar fraction, solar contribution, CO2 avoided, collector temperature, financial analysis etc. are gained using the TSOL 2018 software. To evaluate the active energy for a time period, the daily, monthly and annual performance for three systems which are located in University Clinical Center of Pristine, Kosovo have been analyzed. In addition the results of the mathematical model, simulation and measured solar energy contribution for solar station in Infective disease clinic have been compared. In this paper, a proposal for replacing the conventional water heaters with the domestic solar water heaters (DSWH) is made. A case study for 38289 Residential households in Pristine has been selected. The initial cost of the solar water heater for the city is 60113730 €. The system saves 7274910 € annually and reduced C𝑂2 emission by 22973400 kg. The results from the paper show that the DSWH is economically feasible in Pristine and can result in fuel saving and CO2 emission reduction.

In this paper is going to be proposed a Cell Transmission Model (CTM), its analysis and evaluation with a case study, which addresses in a detailed way the aspect of merging and diverging operations on urban arterials. All those few CTM models that have been developed so far, to model intersections, have some limitations and drawbacks. First, unlike the simple composition road networks, such as highways, urban arterials must include some complex parts called merge sand diverges, due to the fact of vibrational values of reduced capacity, reduced saturation flow rate, etc. In order to simulate an urban network/arterial it is not possible to neglect the traffic signal indication on the respective time step. The objective of this paper is to highlight the difference between the results of the original CTM and our proposed CTM and to provide evidence that the later one is better than the old one.  The proposed and formulated model will be employed through an algorithm of CTM to model a segment- arterial road of Pristina (compound from signalized intersections). For the functionalization and testing of the proposed model is build the experimental setup that is compatible with the algorithm created on C# environment. Results show that the proposed model can describe light and congested traffic condition. In light traffic conditions, in great mass traffic flow is dictated by the traffic signal status, while in medium congestion is obtained a rapid increase of the density to each cell. Fluctuations of the density from the lowest to the highest values are obvious during the first three cycles to all cells of the artery in a congested traffic state. Doi: 10.28991/cej-2021-03091659 Full Text: PDF

On-ramping is being widely used as e method to increase the freeway operational efficiency. The main traffic parameter that must be taken in consideration for the implementation of the feedback control strategies for the on-ramp metering is density on the main section of road. In this paper is given discretized model of traffic which is then improved by a recursive technique called Kalman-Filter with the aid of which is possible to predict the density, by only having the traffic flow measured on the start and end road section. Kalman Filter is based on linear relationship of flow and density. By minimizing the square of error between of the measurements and the estimated values of flows, a gain is derived which then is applied to the densities of the model in order to obtain the greatest accuracy of these values.

Traffic fluctuations are always evident in highways or urban arterial networks that consist of some signalized or unsignalized intersections. Traffic conditions may change as a result of changes in peak timing flows, miscellaneous incidents, variable weather etc. A constant challenge of traffic engineers and professional peoplethat are closely related to traffic control and management remains the identification of parts in which the traffic situation changes and the provision of information about traffic parameters. Prediction of density parameter in short time intervals is important in lots of traffic modelling and control strategies of freeways and urban arterials. For more, the possession of short time density values for particular parts of the freeway segment, plays an importation role on providing drivers with information about events or traffic incidents. Not always the traffic flow amounts are possible to be measured in any part of the segment we are interested in. Thus maycome due to the lack of detector coverage or detecting defects even if it exists. The purpose of this paper is twofold. First is the development of a discrete model so called Cell Transmission Model (CTM) [1,2] that is analogue with approximation of the LWR hydrodynamic model of traffic flow. The second one is the integration of the Kalman Filter [3] to the mentioned model, in order to increase the accuracy of the modeled traffic densities. A Kalman filter (KF) is a recursive algorithm that uses only the previous time-step's prediction with the current measurement in order to make an estimate for the current state. KF does not require previous data to be stored or reprocessed with new measurements. At everyiteration, the KF minimizes the variance of the estimation error, making it an optimal estimator if linear and Gaussian conditions are satisfied. In order to highlight the difference between accuracies of the predictions of the densities