Influence of drag force upon the shortest time trajectory of an aircraft

The shortest time trajectory of an aircraft between two given locations is determined using a simple mathematical model. By taking into account the drag force (viscous friction force with the air), a problem of variational calculus is obtained which consists in determining two functions that minimize a functional, subject to a non-holonomic constraint. The trajectory is determined directly, by numerical integration of Euler equations with multipliers. Three types of drag forces were considered: constant, linear and quadratic. The results are verified through comparison to the values obtained from numerical minimization of the involved functional approximate forms

EFFECTS OF CUSTOMER ORIENTATION, LEARNING ORIENTATION AND INNOVATIVENESS ON HOTEL PERFORMANCE - EVIDENCE FROM CLUJ COUNTY

This paper seeks to relate a strategy of diversification to inovativeness and to the performance of a hotel. Due to the more increased competition within the area of tourism e.g. hotel sector, the need of analyzing the variables mentioned in the title of the paper has become more and more obvious. The first part of the article regards the literature review for the three variables and thus, like an outcome four hypotheses are stated. The second part consists of developing findings for the studied region of Cluj County based on the presented research methodology. The results show that hotel performance is influenced by customer orientation and hotel innovativeness, while the latest one is associated in a positive manner with learning orientation. The three chosen variables could be considered real driven forces for competitiveness in the hotel sector. Thus, any management team should be aware of the results of this study and should create an appropriate environment within the organization able to sustain an expected performance level by focusing on the mentioned variables. Making a deeper analysis about the performance indicators, the results demonstrate the actual development stage of the hotel sector for Cluj County: above the national average, but with potential of growing, mainly from the perspective of efficiency. At this point, management should be aware about how significant could be innovativeness and learning orientation for creating or improving services and delivering processes. In the hotel sector it is very obvious that due to the increased role of employee the awareness is more valuable than in other sectors. Due to the most relevant market segment e.g. business tourism, the studied county is customer oriented and has a good mean value for sales goal achievement, also. In order to improve the profit goal achievement value, innovativeness and learning orientation have to be considered powerful instruments for management team. Taking into consideration the potential of growth in the Romanian hotel sector, we consider that the three chosen variables - customer orientation, learning orientation and innovativeness, should be further analyzed in respect with other performance indicators. Thus, we consider the study being valuable and relevant because it can be expanded not only to other regions - which gives it practical value, but also by including other performance indicators - for academic value

Calculus of axial force in a mechanism using Lagrange equations

Lagrange equations are used to study the motion of a system under the action of known external forces. Besides, based on these equations we can determine the internal force in an arbitrary element of the mechanism acting by active force. If an internal force has to be found, a supplementary mobility related to it is considered in the system. The corresponding internal force for new mobility is found for null values of mobility and of its first and second derivatives. Also the determination of the axial force in the connecting rod of the slider-crank mechanism is presented in this paper as an illustration of this method

Forgotten No More—The Role of Right Ventricular Dysfunction in Heart Failure with Reduced Ejection Fraction: An Echocardiographic Perspective

During the last decade, studies have raised awareness of the crucial role that the right ventricle plays in various clinical settings, including diseases primarily linked to the left ventricle. The assessment of right ventricular performance with conventional echocardiography is challenging. Novel echocardiographic techniques improve the functional assessment of the right ventricle and they show good correlation with the gold standard represented by cardiac magnetic resonance. This review summarizes the traditional and innovative echocardiographic techniques used in the functional assessment of the right ventricle, focusing on the role of right ventricular dysfunction in heart failure with reduced ejection fraction and providing a perspective on recent evidence from literature