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The purpose of this paper is to introduce a spectral model capable of simulating fully transient conductive‐convective heat transfer processes in an axially‐symmetric shallow geothermal system consisting of a borehole heat exchanger embedded in a soil mass.

The proposed model combines the exactness of the analytical methods with important extent of generality in describing the geometry and boundary conditions of the numerical methods. It calculates the temperature distribution in all involved borehole heat exchanger components and the surrounding soil mass using the discrete Fourier transform, for the time domain, and the Fourier‐Bessel series, for the spatial domain.

The paper calculates the temperature distribution in all involved borehole heat exchanger components and the surrounding soil mass in a robust and computationally very efficient procedures. Analysis which might take long time in a work station, if use is made of standard numerical procedures, takes only 1 second in an Intel PC with the proposed model.

The model is capable of simulating fully transient heat transfer in a shallow geothermal system subjected to short and long‐term time varying boundary conditions. The CPU time for calculating temperature distributions in all involved components; pipe‐in, pipe‐out, grout, and soil, using 2048 FFT samples, for the time domain, and 100 Fourier‐Bessel series samples, for the spatial domain, was in the order of 1 second in an Intel PC. The accuracy and computational efficiency of the model makes it, if elaborated, vital for engineering practice.

The proposed model is original and generic. The idea behind it is new and has not been utilized in this field of application. The model can be extended easily to include other types of borehole heat exchangers embedded in multi‐layer systems.

Addresses two difficulties which arise when using a compressible code with equal order interpolation (non‐staggered grids in the finite‐difference nomenclature) to capture a steady‐state solution in the incompressible limit, i.e. at low Mach numbers. Explains that, first, numerical instabilities in the form of spurious oscillations in pressure pollute the solution and, second, the convergence to the steady state becomes extremely slow owing to bad conditioning of the different speeds of propagation. By using a stabilized method, allows the use of equal‐order interpolations in a consistent (weighted‐residual) formulation which stabilizes both the convection and the continuity terms at the same time. On the other hand, by using specially devised preconditioning, assures a rate of convergence independent of Mach number.

In the information theoretic framework, it is customary to address the problem of defining and analyzing complexity and organization of systems either by using Shannon entropy, via Jaynes maximum entropy principle, or by means of the so‐called Kullback informational divergence which measures the informational distance between two probability distributions. In the present paper, it is shown that the so‐called self‐divergence of Markovian processes can be a useful complement in this approach. After a short background on entropy and organization, we recall the definition of divergence of Markovian processes, and then it is used to analyze organization and complexity. We arrive at a principle of maximum self‐divergence which characterizes systems with maximum organization.

A new approach for solving steady incompressible Navier‐Stokes equations is presented in this paper. This method extends the upwind Riemann‐problem‐based techniques to viscous flows, which is obtained by applying modified artificial compressibility Navier‐Stokes equations and fully discrete high‐order numerical schemes for systems of advection‐diffusion equations. In this approach, utilizing the local Riemann solutions the steady incompressible viscous flows can be solved in a similar way to that of inviscid hyperbolic conservation laws. Numerical experiments on the driven cavity problem indicate that this approach can give satisfactory solutions.

A copier management system is now as important an option as a document feed or sorter. There are two main reasons for having a copier management system: to control copier usage, and to collect copier management information automatically. For the first, control may be needed over the use of open‐access copiers. The system might limit use to certain people, ration or charge for copies, or permit copying only within strict security limits. For the second, the automated collection of management information is important to every professional firm that charges out copies to clients. It also concerns any project‐based company which apportions costs accurately to projects. The public sector in particular is becoming increasingly aware of the benefits of cost apportionment on an actual, rather than allocated, basis.

There is a growing debate and research stream on the influence of national culture on the type and nature of management control systems (MCSs) used by organizations in the country. A specific case is the management control of projects executed in a multicultural international environment. The purpose of this paper is to describe the findings of a study into the role of national cultures in controlling a project which a multinational undertook in four countries.

Based on project management control literature a theoretical MCS for international projects is developed. Subsequently, the influence of national culture on this system is discussed, using Hofstede’s cultural dimensions. Then the theoretical system is applied on the project the multinational case company executed in four countries (Austria, Finland, India, and Russia).

A key finding is that different national cultures do require different types of control, but that this effect is neutralized by the culture of the multinational which is the same all over the world and which supersedes national cultures. This makes it possible to implement a standardized project management control framework.

The research yielded a conceptual project management control framework which in practice seemed to be useful for controlling not only the process and progress but also the product (end result) of a project in a multicultural environment.

This paper presents a novel design method for keyboard circuits. The purpose of this study is to enable a single-board computer with fewer pins to recognize a keyboard system consisting of a large number of switches. Through the study of different kinds of keyboard circuits, a general circuit schematic design method is abstracted. Several experiments are conducted to prove the feasibility of the proposed circuit design method.

Conventional circuit schematic diagrams are often limited to two-dimensional planes. Through investigating higher dimensional alternatives, this paper proposes to place components in high-dimensional geometry before connecting all components. A multi-pin switch construction method is proposed to allow the switches to be arranged on the vertices of high-dimensional geometry and be connected sequentially to form the keyboard system. This proposed system can allow a keyboard system consisting of a large number of switches to be recognized by a single-board computer with less available pins.

The design scheme proposed in this paper can read more switch states with limited Input/Output pins. With the increase of the number of Input/Output ports and pins, the number of simultaneously identifiable switches increases exponentially, which is suitable for sensor design of array type.

Compared with the classical keyboard circuits, the circuit designed using the proposed method will lead to a slightly longer recognition time for each key. This can be compensated by a single-board computer with a modestly higher clock speed.

The circuit schematic design method based on high-dimensional geometry is introduced for the first time. The feasibility of the proposed method is verified by the original experiments. The proposed approach is of importance in guiding the design of new analog and digital sensor circuit systems.

This study aims to give a description of conformal transformation Cartesian coordinates into spiral coordinates using the example of roll powder sintering (RPS) additive manufacturing (AM) technology. RPS has several advantages over dominant AM processes currently available in the market. RPS allows accomplishing designs, which are impossible, very expensive and difficult to create by other methods. The technology requires slicing a 3D object with spiral scanning.

The paper describes the possibility of accurate 3D object transformation into a flat ribbon by spiral coordinate system. Parameters of conformal transformation are calculated according to the equation of equivalence between (x, y, z) and (l, z) coordinates.

As numerical examples show, it is possible to convert three-dimensional space to two-dimensional one if you know the thickness of the spatial layer. The proposed methodology can be used for the transformation of 3D computer-aided design models into 2D strip models.

In this paper, the author proposes a method of converting Cartesian coordinates into spiral coordinates. Conformal transformation of three-dimensional space to two-dimensional one by use of spiral coordinate system is demonstrated by RPS AM technology, which allows to produce objects with high accuracy.

This paper aims to investigate the thermal characteristics of the clutch hydraulic system under various oil flow conditions. Increasing the oil flow is one of the most important approaches to reduce the clutch temperature. However, the effect of the oil flow on the clutch temperature remains to be explored.

The thermal resistance network model and the lumped parameter method are used to study the thermal characteristics of the clutch hydraulic system. The predicted temperature variations of the clutch and the oil are compared with experimental data.

Results demonstrate that the larger the friction power is, the higher the temperatures of the clutch and the oil are. However, the temperature growth rates of the clutch and oil present different trends: the former decreases gradually and the latter increases constantly. Additionally, increasing the oil flow within a certain range gives rise to the decrease of clutch temperature and the increase of oil temperature; nevertheless, their variation trends are gradually weakening. When the oil flow is large enough, it brings a slight effect on the clutch temperature rise.

This paper extends the knowledge into the oil flow supply of the clutch hydraulic system. The conclusions can provide a theoretical guidance for the oil management of the transmission system. Additionally, the thermal resistance network model is also effective and efficient for other hydraulic equipment to predict the temperature variation.

The paper aims to develop a realistic, yet flexible model of insurer net worth.

Inspired by and as an improvement to Powers, the paper develops a multi‐dimensional diffusion model to describe the operations of an insurance company. The paper then explores whether or not this multi‐dimensional model can be approximated conservatively by a homogeneous one‐dimensional diffusion.

The multi‐dimensional model that is proposed can be approximated conservatively by a homogeneous one‐dimensional diffusion, which is clearly much easier to solve analytically or numerically than a multi‐dimensional system. Also, the Laplace transform of the desired first‐passage time (to ruin) distribution can be stated analytically.

The analysis provides a theoretical model of the relationship between the insurer's ruin‐time distribution and many aspects of the insurer's operations, including loss‐payout patterns, premium‐earning patterns, and investment strategy.

The paper reveals that a multi‐dimensional model can be approximated by a homogeneous one‐dimensional diffusion to achieve a realistic and flexible model that can be used practically.