E-characteristic polynomials of real rectangular tensor

By the resultant theory, the E-characteristic polynomial of a real rectangular tensor is defined. It is proved that an E-singular value of a real rectangular tensor is always a root of the E-characteristic polynomial. The definition of the regularity of square tensors is generalized to the rectangular tensors, and in the regular case, a root of the E-characteristic polynomial of a special rectangular tensor is an E-singular value of the rectangular tensor. Moreover, the best rank-one approximation of a real partially symmetric rectangular tensor is investigated.     

Effects of a flexible joint on instability of a free-free jointed bipartite beam under the follower and transversal forces

This paper deals with the problem of the instability regions of a free-free flexible jointed bipartite beam under the follower and transversal forces as a realistic simulation of a two-stage aerospace structure. The aim of this study is to analyze the effects of the characteristics of a flexible joint on the beam instability to use maximum bearable propulsion force. A parametric study is conducted to investigate the effects of the stiffness and the location of the joint on the critical follower force by the Ritz method and the Newmark method, then to research the vibrational properties of the structure. It has been shown that the nature of instability is quite unpredictable and dependent on the stiffness and the location of the joint. The increase of the follower force or the transversal force will increase the vibration of the model and consequently cause a destructive phenomenon in the control system of the aerospace structure. Furthermore, this paper introduces a new concept of the parametric approach to analyze the characteristics effects of a flexible two-stage aerospace structure joint design.     

Dynamic response of a beam on a Pasternak foundation and under a moving load

The dynamic response of an infinite beam placed on a Pasternak foundation when the system was subjected to a moving load was investigated. We used the double Fourier transform and its inversion to solve the formulations of the problem. A closed form analytic solution of the beam was obtained by the theorem of residues. We selected a numerical example to illustrate the dynamic response of the beam on Pasternak and Winkler foundations, respectively. We discuss the effect of the moving load velocity on the dynamic displacement response of the beam. The maximum deflection of the beam increases slightly with increased load velocity but increases significantly with reduced shear modulus of subgrade at a given velocity. The maximum deflection of a beam resting on a Pasternak foundation is much smaller than that of a beam on a Winkler foundation.     

New Methods in Design Education： The Systemic Methodology and the Use of Sketch in the Conceptual Design Stage

This study describes the application of a new product concurrent design methodologies in the context in the education of industrial design. The use of the sketch has been utilized many times as a tool of creative expression especially in the conceptual design stage, in an intuitive way and a little out of the context of the reality needs that the design should be attended. This methodology systematizes and guides the process of sketching by means of a conceptual model and a geometric model toward a feasible solution, complementing the role of the sketch in the phase of a product conceptual design. The model describes its operating principles, as well as the phases of implementation in the context of teaching the industrial design illustrated with projects carried out in the workshop of conceptual design of the University Technical College of Valencia and University of the Bio-Bio, Chile. Finally, we discuss the implementation of the systemic models, their relation with the optimisation of the sketching process in the conceptual design stage, and their implications in the educational context.     

What Was the Riddle of the Sphinx？

The Sphinx was a make-belive animal of long ago.It had the head of a person, the body of a lion,and the wings of a bird.The Sphinx lived near a city called Thebes.     

Death of a Salesman and American Dream

American Dream refers to the belief of the majority of Americans.Through hard work,thrift,and determination,they can surely achieve a better life and live a comfortable life.Such an American Dream has a profound influence on several generations of Americans.American Dream has a close relationship with people’ s working life and cultural activities.Death of a Salesman is a typical play about the pursuit and the illusionary of the Dream follower.In Death of a Salesman,the American Dream is the main hero as well as Willy Loman’ s spiritual pillar.The pursuit,the realization,and the disillusionment of the American Dream develop with Willy and his family.     

English Noun Inflections in Different Periods

One of the distinguishing featuros of English is its inflections, which experiencedchanges in the different periods. Old English is known as a language of full Inflections,Middle English as a language of leveling inflections and Modern English as a language oflost inflections. The history of English is in part the history of the gradual loss of the inflection system.Definition of inflectionInflection is the process of varying the form of a word to differentiate related meanings or uses. Fo…     

Solution of a rigid disk on saturated soil considering consolidation and rheology

INTRODUCTION An important problem in foundation engineeringis the determination of the rate of settlement of a raftfoundation placed on a deep clay layer. Gibson andMcNamee (1957), and McNamee and Gibson (1960a;1960b) considered the problem of normal uniformloading applied to the surface of a half-space andshowed that one-dimensional theory gives a markedunderestimate of the rate of settlement. This theorycorresponds to the case of a perfectly flexible footing.However, it is often…     

Earth return path impedances of underground cable for three-layer earth

One of the factors that affect the parameters of an underground cable is earth return path impedance. Pollaczek developed a formula for the case of one-layer （homogenous） earth. But in practice the earth is composed of several layers. In this study we develop a new formula for earth return path impedance in the case of a three-layer earth. To check the accuracy of the obtained results, a comparison has been made with the finite element method （FEM）. A comparison between the results of the Pollaczek formula and results of the obtained formula for a three-layer earth has been made, showing that the use of the Pollaczek formula instead of the actual formula can cause serious errors.     

青春寄语

Youth is not a time of life; it is a state of mind; it is not a matter of rosycheeks, red lips and supple(柔韧的)knees; it is a matter of will, a quality of imagination, a vigor of the emotions; it is the freshness of the deep springs of life.Youth means a temperamental predominance(支配,主导)of courage over timidity(胆怯),of the appetite for adventure over the love of ease. This often exists in a man of 60 more than a boy of 20. Nobody grows old merely by a number of