A DP Approach to Hamiltonian Path Problem

A Dynamic Programming based polynomial worst case time and space algorithm is described for computing Hamiltonian Path of a directed graph. Complexity constructive proofs along with a tested C++ implementation are provided as well. The result is obtained via the use of original colored hypergraph structures in order to maintain and update the necessary DP states

Facing Difficult Choices: The South Caucasus between Russia and the European Union

The mounting tension over Ukraine has introduced numerous dangers to the security situation in the South Caucasus. These negative ramifications are further exacerbated by the fact that Russia holds the key to resolving conflicts in the post-Soviet realm, especially in the absence of greater Western assertiveness. But Moscow and Brussels are caught up in geopolitical competition over the region. Such continued competition prolongs the cycles of instability and could sooner or later spill over into Russia and the EU. Devising a coherent strategy for the region that focuses on an integrated, coordinated approach and recognizes the shared interests of Russia, the EU, and the South Caucasus countries is a pressing challenge that remains unmet

A Simulation for Determining the Relation between Position of the Center Mass and the Impact of the Accident's Fatality on the Car Driver.

The most dangerous type of collision between two cars is a head on collisions, which can be fatal to either or both drivers. The data collected on that suggest the risk of fatality to driver is less if that driver has a passenger or passengers in that car. The main objective of this study is to show with a help of simulation the relation between position of the center mass and the impact of the accident's fatality on the drivers. Moreover, this report starts with the statement of the problem and the theoretical knowledge of the project. Then on the way the software used for simulation is included with the results. As a result many figures can be seen and the various relations between accident concepts can be found. Later the calculation part justifies the obtained results as a proof. Following the discussion part explains about the problem faced during preparation of this project. Through discussions the report moves to conclusion and recommendations

Renewable Energy Transition Task Solution for the Oil Countries Using Scenario-Driven Fuzzy Multiple-Criteria Decision-Making Models: The Case of Azerbaijan

The renewable energy transition of oil- and gas-producing countries has specific peculiarities due to the ambivalent position of these countries in the global energy market, both as producers and consumers of energy resources. This task becomes even more challenging when the share of oil and gas in the country’s GDP is very high. These circumstances pose serious challenges for longterm energy policy development and require compromising decisions to better align the existing and newly created energy policies of the country. The scale, scope, and pace of changes in the transition process must be well balanced, considering the increasing pressure of economic and environmental factors. The objective of this paper is to develop models that allow the selection of the most appropriate scenario for renewable energy transition in an oil- and gas-producing country. The distinguishing feature of the proposed model is that alternatives in the decision matrix are presented as scenarios, composed of a set of energy resources and the level of their use. Linguistic descriptions of the alternative scenarios are formalized in the form of fuzzy statements. For the problem solution, four different Multiple-Criteria Decision-Making (MCDM) methods were used: the fuzzy simple additive weighting (F-SAW) method, the distance-based fuzzy TOPSIS method (Technique of Order Preference Similarity to the Ideal Solution), the ratio-analysis-based fuzzy MOORA method (Multi- Objective Optimization Model Based on the Ratio Analysis), and the fuzzy multi-criteria optimization and compromise solution method VIKOR (Serbian: VIekriterijumsko Kompromisno Rangiranje). This approach is illustrated using the example of the energy sector of Azerbaijan. The recommended solution for the country involves increasing natural gas (NG) moderately, maintaining hydro, and increasing solar notably and wind moderately

Fuzzy Information and Z-number-based Approaches to Energy Resource Selection

In this paper, we study models for ranking renewables and a mix of energy resources in the development of long-term energy policy. Energy resource selection is a multi-criteria decision-making problem, characterized by incomplete information, uncertainties and intangibles, competitive priorities and contradictory requirements. The uniqueness of the problem and the limited relevant data necessitates the use of expert opinion as a principal source of information. All these factors contribute to subjectivity and vagueness in the decision-making process. Taking into consideration these circumstances, fuzzy information and a Z-number-based analytic hierarchy process (AHP) has been used as a decision-making tool. Z–number represents both the restriction and the reliability of evaluation and, due to these characteristics, it provides a better description of the uncertainty. Numerical examples and comparative analysis of fuzzy and Z-number-based models illustrate the process to solution and results

ANALYSIS OF THE CONDITION OF A PIPE FIXED IN A CLAMPING DEVICE

Due to the fact that clamping devices are widely used in various industries, the requirements for the operation of such devices are constantly increasing. This is due to an increase in the general requirements for processing accuracy, as well as an increase in the forces acting on the clamped part. The reliability of these devices when working with thin-walled cylindrical parts is of great importance. Thin-walled cylinders used in mechanical engineering are subject to significant loads. With prolonged exposure to loads from clamping forces, as well as from axial tensile forces, plastic deformations of cylindrical parts occur. In the oil and gas industry, when clamping drill and casing pipes in some areas in the capture zone, stresses exceed the yield strength. Multiple clamping of the pipe will reduce the pipe wall in the gripping area, which causes premature pipe failure. Therefore, increasing the holding capacity of clamping mechanisms is relevant. Analysis of broken drill pipes, which have been operating in wedge grips for a long time, showed that in most cases the pipes undergo plastic deformation caused by damage to the pipe surface by the teeth of the ram. To clarify the actual conditions of loading the pipe and the possibilities of increasing the capacity of the clamping devices, studies of the contact pressures in the clamping zone were carried out. A new pipe clamping chuck is also presented, which provides a sufficiently high reliability of fastening of cylindrical parts

Development of a method for the combined control of the hardness of winding textile package

Analysis of methods for determining the hardness of the winding shows that all existing methods require a lot of labor and time. When measuring the layer-by-layer hardness, the known methods do not allow obtaining continuous values, and in the case of measuring the hardness of packages of complex shape (conical bobbins, cops, spinning cobs, etc.), it requires a calculation using cumbersome formulas. In this case, the main difficulties arise in determining the volume of the layers of the winding, which in the general case have a complex configuration, and due to defects in the winding may have an irregular shape. Obviously, the described technique is rather cumbersome, and a lot of measurements and calculations are required to obtain a graph of the change in the winding hardness along the package radius. The construction of a graph of the change in hardness along the generatrix using a special device is generally problematic, since placement of more than three sources on the device is impossible due to the size of the meters, and the construction of the curve by three points cannot be considered satisfactory. Winding hardness is one of the most important parameters, on which many technological properties of the package depend. Indeed, with an increase in the hardness of the winding, the amount of material in the same volume increases, which makes it possible to replace packages less often, both on the machine that forms them, and at the subsequent transition. As a result, the equipment useful time increases. It was found that the hardness of the winding is closely related to its rigidity, and hence to the stability during transportation. The hardness of the winding affects the permeability of the package when it is treated with solutions. In this case, a huge role is played not only by the average value of the hardness, but also by its distribution over the layer