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The boundary element method is a useful method for the analysis of field problems involving unbounded regions. Therefore, the method can be used advantageously in…
The boundary element method is a useful method for the analysis of field problems involving unbounded regions. Therefore, the method can be used advantageously in combination with the finite element method. This is sometimes called a combination method and it is suitable as a picture‐frame technique. Although this technique attains good accuracy, the matrix of the discretized equation is not banded, since it is a dense matrix. In this paper, we propose an infinite boundary element which divides the unbounded region radially. By the use of this element, the bandwidth of the discretized system matrix does not increase beyond that of the finite element region and its original matrix structure is maintained. The infinite boundary element can also be applied to homogeneous unbounded field problems, for which the Green's function of the mirror image is difficult to use. To illustrate the validity of the proposed technique, some numerical calculations are demonstrated and the results are compared with those of the usual combination method and the method using the hybrid‐type infinite element.
Studies in psychology have long revealed that making personal choice involves multiple motivational consequences. It has only been recent, however, that the literature on…
Studies in psychology have long revealed that making personal choice involves multiple motivational consequences. It has only been recent, however, that the literature on neuroscience started to examine the neural underpinnings of personal choice and motivation. This chapter reviews this sparse, but emergent, body of neuroscientific literature to address possible neural correlates underlying personal choice. By conducting the review, we encourage future systematic research programs that address this topic under the new realm of “autonomy neuroscience.” The chapter especially focused on the following motivational aspects: (i) personal choice is rewarding, (ii) personal choice shapes preference, (iii) personal choice changes the perception of outcomes, and (iv) personal choice facilitates motivation and performance. The reviewed work highlighted different aspects of personal choice, but indicated some overlapping brain areas – the striatum and the ventromedial prefrontal cortex (vmPFC) – which may play a critical role in motivational processes elicited by personal choice.
Motivation significantly influences learning and memory. While a long history of research has focused on simple forms of associative learning, such as Pavlovian…
Motivation significantly influences learning and memory. While a long history of research has focused on simple forms of associative learning, such as Pavlovian conditioning, recent research is beginning to characterize how motivation influences episodic memory. In this chapter we synthesize findings across behavioral, cognitive, and educational neuroscience to characterize motivation’s influence on memory. We provide evidence that neural systems underlying motivation, namely the mesolimbic dopamine system, interact with and facilitate activity within systems underlying episodic memory, centered on the medial temporal lobes. We focus on two mechanisms of episodic memory enhancement: encoding and consolidation. Together, the reviewed research supports an adaptive model of memory in which an individual’s motivational state (i.e., learning under states of reward or punishment) shapes the nature of memory representations in service of future goals. The impact of motivation on learning and memory, therefore, has very clear implications for and applications to educational settings.
Infinite elements provide one of the most attractive alternatives for dealing with differential equations in unbounded domains. The region where loads, sources, inhomogeneities and anisotropics exist is modelled by finite elements and the far, uniform region is represented by infinite elements. We propose a new infinite element which can represent any type of decay towards infinity. The element is so simple that explicit expressions can be obtained for the element matrix in many cases, yet large improvements in the accuracy of the solution are obtained as compared with the truncated mesh. Explicit expressions are in fact given for the Laplace equation and 1/rn decay. The element is conforming with linear triangles and bilinear quadrilaterals in two dimensions. The element can be used with any standard finite‐element program without having to modify the shape function library or the numerical quadrature library of the program. The structure or bandwidth of the stiffness matrix of the finite portion of the mesh is not modified when the infinite elements are used. An example problem is solved and the solution found to be better than several other methods in common usage. The proposed method is thus highly recommended.
The combination method, combined finite element‐boundary element approach, is suitable for unbounded field problems. Although this technique attains a high degree of…
The combination method, combined finite element‐boundary element approach, is suitable for unbounded field problems. Although this technique attains a high degree of accuracy, the matrix of the discretized system equation is not banded but sometimes densely or sparsely populated. We reported the development of an infinite boundary element for 2‐D Laplace problems, with which the bandwidth of the discretized system matrix does not increase beyond that of the finite element region. In this paper, we extend this approach and propose another infinite boundary element for 2‐D Helmholtz problems. To illustrate the validity of the proposed technique, some numerical examples are given and their results are compared with those of other methods.
The finite‐element method can be used for an approximate solution of axisymmetric exterior‐field problems by truncating the unbounded domain, or by applying various…
The finite‐element method can be used for an approximate solution of axisymmetric exterior‐field problems by truncating the unbounded domain, or by applying various techniques of coupling a finite region of interest with the remaining far region, which is properly modelled. In this paper, we propose the solution of axisymmetric exterior‐field problems by using the standard finite‐element method in a bounded, transformed domain obtained by conformal mapping from the original, unbounded one. The transformed functionals have very simple expressions and the exact transforms of the original boundary conditions are used in the transformed domain. Consequently no approximation is introduced in the proposed method and improvements in the accuracy of the solution are obtained as compared with several other methods in common usage, especially with the truncated mesh technique. A few example problems are solved and the presented method is found to be simple and computationally highly efficient. It is particularly recommended for problems with material inhomogeneities and anisotropies within large regions.
Survey of period infinite element developments The first infinite elements for periodic wave problems, as stated in Part 1, were developed by Bettess and Zienkiewicz, the…
Survey of period infinite element developments The first infinite elements for periodic wave problems, as stated in Part 1, were developed by Bettess and Zienkiewicz, the earliest publication being in 1975. These applications were of ‘decay function’ type elements and were used in surface waves on water problems. This was soon followed by an application by Saini et al., to dam‐reservoir interaction, where the waves are pressure waves in the water in the reservoir. In this case both the solid displacements and the fluid pressures are complex valued. In 1980 to 1983 Medina and co‐workers and Chow and Smith successfully used quite different methods to develop infinite elements for elastic waves. Zienkiewicz et al. published the details of the first mapped wave infinite element formulation, which they went on to program, and to use to generate results for surface wave problems. In 1982 Aggarwal et al. used infinite elements in fluid‐structure interaction problems, in this case plates vibrating in an unbounded fluid. In 1983 Corzani used infinite elements for electric wave problems. This period also saw the first infinite element applications in acoustics, by Astley and Eversman, and their development of the ‘wave envelope’ concept. Kagawa applied periodic infinite wave elements to Helmholtz equation in electromagnetic applications. Pos used infinite elements to model wave diffraction by breakwaters and gave comparisons with laboratory photogrammetric measurements of waves. Good agreement was obtained. Huang also used infinite elements for surface wave diffraction problems. Davies and Rahman used infinite elements to model wave guide behaviour. Moriya developed a new type of infinite element for Helmholtz problem. In 1986 Yamabuchi et al. developed another infinite element for unbounded Helmholtz problems. Rajapalakse et al. produced an infinite element for elastodynamics, in which some of the integrations are carried out analytically, and which is said to model correctly both body and Rayleigh waves. Imai et al. gave further applications of infinite elements to wave diffraction, fluid‐structure interaction and wave force calculations for breakwaters, offshore platforms and a floating rectangular caisson. Pantic et al. used infinite elements in wave guide computations. In 1986 Cao et al. applied infinite elements to dynamic interaction of soil and pile. The infinite element is said to be ‘semi‐analytical’. Goransson and Davidsson used a mapped wave infinite element in some three dimensional acoustic problems, in 1987. They incorporated the infinite elements into the ASKA code. A novel application of wave infinite elements to photolithography simulation for semiconductor device fabrication was given by Matsuzawa et al. They obtained ‘reasonably good’ agreement with observed photoresist profiles. Häggblad and Nordgren used infinite elements in a dynamic analysis of non‐linear soil‐structure interaction, with plastic soil elements. In 1989 Lau and Ji published a new type of 3‐D infinite element for wave diffraction problems. They gave good results for problems of waves diffracted by a cylinder and various three dimensional structures.
Computer programs were developed based on the finite element method and the charge simulation method for the calculation of three dimensional electric fields in high…
Computer programs were developed based on the finite element method and the charge simulation method for the calculation of three dimensional electric fields in high voltage engineering. A brief description of the applied methods with respect to the special requirements of high voltage engineering is presented. In order to use the specific advantages of the finite element method and the charge simulation method, two procedures combining both methods are proposed: an iterative method and a direct method. For the calculation of three dimensional problems without symmetry the iterative procedure has the advantage that the coupling program is small compared with the field calculation programs and no major changes in these programs are necessary.
A technique combining finite elements and boundary elements is promising for unbounded field problems. A hypothetical boundary is assumed in the unbounded domain, and the…
A technique combining finite elements and boundary elements is promising for unbounded field problems. A hypothetical boundary is assumed in the unbounded domain, and the usual finite element method is applied to the inner region, while the boundary element method is applied to the outer infinite region. On the coupling boundary, therefore, both potential and flux must be compatible. In the finite element method, the flux is defined as the derivative of the potential for which a trial function is defined. In the boundary element method, on the other hand, the same polynomial function is chosen for the potential and the flux. Thus, the compatibility cannot be satisfied unless a special device is considered. In the present paper, several compatibility conditions are discussed concerning the total flux or energy flow continuity across the coupling boundary. Some numerical examples of Poisson and Helmholtz problems are demonstrated.
The purpose of this paper is to examine how internationally recognized styles of transactional, instructional, transformational and distributed leadership have emerged in…
The purpose of this paper is to examine how internationally recognized styles of transactional, instructional, transformational and distributed leadership have emerged in the Japanese education system.
National legislation and policy documents in Japan since 1945 were collected by searching for the word “principal” or “head of school.” Then, four types are excluded: those that are unique only to one school type, do not explicitly deal with the role of the principal, are in subordinate laws prescribing contents that essentially overlap with those in superordinate statutes and define procedural roles of the principal. As a result, 17 legal provisions and 35 policy documents remained, each of which was analyzed by using four leadership styles.
Despite an increasing focus on instructional, transformational and distributed styles, Japan has not comprehensively articulated attributes and abilities expected of the principal. Additionally, a movement away from instructional leadership in the 2000s contrasts with the recent emphasis on “educational leadership.” Moreover, transformational leadership has centered on the school–family–community collaboration and the expansion of principal autonomy, and distributed leadership has taken the forms of new positions that support the principal, both of which were influenced by the decentralization movement.
It points to the susceptibility of the role of the principal in Japan and western countries alike to broader structural reforms but with different implications and distinct timing of the advent of leadership styles among them. Additionally, Japan has adopted a modified approach to distributed leadership style, which is somewhat similar to delegation, to make a compromise between the emergent theory and the centrality of the principal in the school hierarchy. Furthermore, instructional leadership seems to be a “late bloomer” in Japan because of its practice-based nature and unsuitability to daily realities of the principal.
As an arguably unprecedented attempt to apply leadership styles to legislation and policy documents, this study builds a foundation for understanding how school leadership is shaped by education policies. Moreover, while making connections to the western view, it creates a paradigm for future studies of school leadership in Japan and in the field of comparative educational administration.