N-dimensional Models Research Articles

The Barrier Factors to the Implementation of Building Information Modelling for Construction Industry in Sarawak

Building Information Modelling (BIM) Construction Lifecycle Process offers digital construction solutions throughout the whole project lifecycle by providing sustainable productivity and quality and increasing the work collaboration and efficiency of the design teams. BIM represents the development and application of computer-generated n-dimensional (n-D) models to simulate building construction planning, design, construction, and operation. In Sarawak, the BIM technology does not meet the construction stakeholder's expectations during the project lifecycles in different stages, which resulted in low BIM implementation. Therefore, this research study aims to identify the salient barrier factors to the implementation of BIM in the Sarawak construction industry, specifically in the design stage. To achieve the research study, the methodology is applied through literature review, followed by an online interview with BIM experts in Sarawak Construction Industry. Lastly, the findings of this study indicate the most salient factors faced by the Sarawak construction industry until the present, in terms of Technology, Cost, Management, Personal and Policy, such as (1) Lack of active participation from consultants in the project team, (2) Low enforcement from client, (3) Lack of senior management support, (4) Lack of desire to change of the older generation to implement BIM and (5) Lack of the knowledge regarding the cost benefits for implementing BIM.

Modeling of transport flows of energy resources in digital logistics based on the methodology of multidimensional network structures.

The article presents an approach used to analyze network streaming phenomena and processes of transfer of continuous and discrete traffic flows over network-like n-dimensional network structures. The authors have developed an approach focused on developing algorithms embedded in the servers of integrated platforms to function logistics network processes and are in demand for forming a stable digital environment. The originality of the authors’ approach lies in expanding the theoretical apparatus of management by including software solutions built based on complex mathematical n-dimensional models. The proposed research results develop a general approach to solving one-dimensional network logistics problems. Until recently, as a rule, in the formulation of logistic problems, only one-dimensional supply chains or simple problems of forming customer value on mathematical graphs were used, in the form of which the image of network logistic and commercial structures is presented. The feature under consideration is always present in the movement processes of continuous flows of energy resources between the nodes of the logistics network. The proposed methodology of multidimensional network structures can also be extended to a more general case of modeling discrete traffic flows in digital logistics.

An analytical formulation for multidimensional continuous opinion models

Usually, opinion formation models assume that individuals have an opinion about a given topic which can change due to interactions with others. However, individuals can have different opinions on different topics and therefore n-dimensional models are best suited to deal with these cases. While there have been many efforts to develop analytical models for one dimensional opinion models, less attention has been paid to multidimensional ones. In this work, we develop an analytical approach for multidimensional models of continuous opinions. We show that for any generic reciprocal interactions between agents, the mean value of initial opinion distribution is conserved. Moreover, for positive social influence interaction mechanisms, the variance of opinion distributions decreases with time and the system converges to a delta distributed function. In particular, we calculate the convergence time when agents get closer in a discrete quantity after interacting, showing a clear difference between cases where the approach is through Manhattan or Euclidean distance.

Research on Computer BIM Technology in Whole Process Dynamic Control of Construction Cost

BIM has become an important resource in construction engineering, which has a single engineering data source. Through BIM, we can solve the compatibility problem between distributed and heterogeneous engineering data. Through BIM, we can make the whole life cycle management of construction engineering, which will better realize the creation, management and sharing of dynamic engineering information. Through BIM, we can complete the Whole process (hereinafter referred to as WP) management of planning, design, construction and maintenance. Using BIM, we can update the calculation and evaluation of engineering quantity in real time, which will evaluate the design change more accurately. Therefore, BIM plays an important role in the WP dynamic control (hereinafter referred to as DC) of construction cost (hereinafter referred to as CC). Through BIM, we can carry out complex structural calculation, which will simplify the steps of project cost. BIM Technology has integrated two-dimensional, three-dimensional, four-dimensional and even n-dimensional models. BIM model has integrated all kinds of information of building life cycle, which can break the original separate cost management (hereinafter referred to as CM) mode. Through BIM, we have realized the integration of project CM of various specialties and stages, which is the WP CM mode of construction engineering.

Generalized Lorenz equations on a three-sphere

Edward Lorenz is best known for one specific three-dimensional differential equation, but he actually created a variety of related N-dimensional models. In this paper, we discuss a unifying principle for these models and put them into an overall mathematical framework. Because this family of models is so large, we are forced to choose. We sample the variety of dynamics seen in these models, by concentrating on a four-dimensional version of the Lorenz models for which there are three parameters and the norm of the solution vector is preserved. We can therefore restrict our focus to trajectories on the unit sphere S 3 in ℝ4. Furthermore, we create a type of Poincare return map. We choose the Poincare surface to be the set where one of the variables is 0, i.e., the Poincare surface is a two-sphere S 2 in ℝ3. Examining different choices of our three parameters, we illustrate the wide variety of dynamical behaviors, including chaotic attractors, period doubling cascades, Standard-Map-like structures, and quasiperiodic trajectories. Note that neither Standard-Map-like structure nor quasiperiodicity has previously been reported for Lorenz models.

Global stability in n-dimensional discrete Lotka-Volterra predator-prey models

There are few theoretical works on global stability of Euler difference schemes for two-dimensional Lotka-Volterra predator-prey models. Furthermore no attempt is made to show that the Euler schemes have positive solutions. In this paper, we consider Euler difference schemes for both the two-dimensional models and n-dimensional models that are a generalization of the two-dimensional models. It is first shown that the difference schemes have positive solutions and equilibrium points which are globally asymptotically stable in the two-dimensional cases. The approaches used in the two-dimensional models are extended to the n-dimensional models for obtaining the positivity and the global stability. Numerical examples are presented to verify the results.MSC: 34A34, 39A10, 40A05.

Is BIM Adoption Advantageous for Construction Industry of Pakistan?

Lack of Information technology applications on construction projects lead to complex flow of data during project life cycle. Building Information Modeling (BIM) has gained attention in the Architectural, Engineering and Construction (AEC) industry, envisage the use of virtual n-dimensional (n-D) models to identify potential conflicts in design, construction or operational of any facility. A questionnaire has been designed to investigate perceptions regarding BIM advantages. Around 102 valid responses received from diversified stakeholders. Results showed very low BIM adoption with low level of ‘Buzz’. BIM is a faster and more effective method for designing and construction management, it improves quality of the design and construction and reduces rework during construction; which came out as the top thee advantages according to the perception of AEC professionals of Pakistan.BIM has least impact on reduction of cost, time and human resources. This research is a bench mark study to understand adoption and advantageous of BIM in Pakistan Construction Industry.

An Integral Representation for Ising Models

An integral representation for the partition function for general n-dimensional Ising models with nearest or non-nearest neighbors interactions in a bounded region is given. The representation is used to derive some properties of the partition function. The results are generalized to the case of higher spin Ising models.

Equivalence of n-dimensional Roesser and Fornasini-Marchesini models

An equivalent Roesser model is obtained for an arbitrary Fornasini-Marchesini model in n-dimensions and vice-versa. Both the regular and singular cases are covered.

Model quality evaluation in H/sub 2/ identification

Model quality evaluation in set-membership identification is investigated, In the recent literature, two main approaches have been used to investigate this problem, based on the concepts of n-width and of radius of information. In this paper it is shown that the n-width is related to the asymptotic value of the conditional radius of information of the identification problem with noise free measurements. Upper and lower bounds of the conditional radius of information are derived for the H/sub 2/ identification of exponentially stable systems using approximating n-dimensional models linear in the parameters in the presence of power bounded measurement errors. The derived bounds are shown to be convergent to the radius for a large number of data and model dimensions. Moreover, a formula for computing the worst case identification error for any linear algorithm is given. In particular, it is shown that the identification error of the least square algorithm may be increasing with respect to the model dimension (peaking effect), An almost-optimal linear algorithm is presented, that is not affected by this peaking effect, and indeed is asymptotically optimal.

Classical perturbation theory of the thermal accommodation coefficient in n dimensions

The theory of the thermal accommodation coefficient is studied using a classical perturbation theory, in which the solid is represented by various n-dimensional models. A general formula is found for the effective thermal accommodation coefficient of a single gas atom in terms of a summation over the normal modes of vibration of the model; this formula applies to any classical harmonic model of the solid. From this formula are derived expansions in closed form for the effective thermal accommodation coefficient which are valid in the regimes of high and low incident gas atom speed; attempts are made to define the conditions under which these expansions are valid. The theory restricts all motion to the direction normal to the solid surface, and all gas atom-surface atom collisions are head-on. A modified exponential repulsive gas-solid interaction potential function which includes realistically a long-range gas-solid attraction is used; a consequence of the form of this potential function is that the perturbation theory is not restricted in general to small accommodation coefficients. In the low-speed regime the theory is not restricted in general to small gas atomic mass, but this restriction applies in the high-speed regime. The theory is applied in turn to the following models of the solid: the n-dimensional lattice with different central and non-central spring force constants; the one-dimensional lattice with a surface impurity; the n-dimensional lattice with various types of surface impurity; the n-dimensional continuum. Where appropriate, the physical significance of the results of these models is considered, and relations among the results are studied; in this way, for example, the role of the three-dimensional continuum theory of Landau is clarified. It is shown that great care must be taken in using such perturbation theory expansions, as they apply only to a very limited group of experimental systems. It is concluded that, in fact, no satisfactory comparison with experimental data is possible at present, and the need is stressed for a more general theory. That the much-used one-dimensional model is not useful in any regime for realistic studies of gas-surface interactions is conclusively established in various ways; similar remarks will apply also to one-dimensional quantum-mechanical models.