242 research outputs found
An Approach to Distributed Modeling
Many works on analyzing the behavior of complex systems are based on building large-scale integrated models and sequentials using decomposition and aggregation procedures. In this paper an approach is described which permits to investigate a set of linked subsystems without explicitly building any integrated model.
This approach based on the 'smooth' version of the Sequential Unconstrained Minimization Techniques (SUMT) can be considered from a mathematical point of view as a realization of the 'general decomposition scheme' (Orchard-Hays 1968).
Section 1 describes the statement of the problem; Section 2 gives a general description of the idea of the SUMT; Section 3 contains the conditions of applicability of the approach; and in Section 4 we give a short description of the practical realization and computer testing of this method for a case of linking two submodels of a health care system
Linkage of Regional Models
For several years the activities of the Regional Development Task at the International Institute for Applied Systems Analysis (IIASA) have been directed towards the development of a system of regional models, the elements of which were elaborated over. the period 1977-1979. The final stage of the work, which involves the coordination of these individually developed models, is now nearing completion. However, before this system can become fully operational, three major problems have to be overcome. They concern the modeling approach, level of aggregation, and method of coordination to be used. The linkage problem is examined in this paper
ОСОБЕННОСТИ ПАТОГЕНЕЗА, КЛИНИКИ И ДИАГНОСТИКИ ЭКВИНО-ПЛАНО-ВАЛЬГУСНОЙ ДЕФОРМАЦИИ СТОП У БОЛЬНЫХ ДЕТСКИМ ЦЕРЕБРАЛЬНЫМ ПАРАЛИЧОМ
By data of the literature and own supervision, authors describe features pathogenesis of equinoplanovalgus foot deformations (EPVFD) in cerebral palsy patients and also the clinical displays of disease revealed by them at inspection of 52 patients (79 foot). In article you can find the earlier not described clinical supervision - presence by a considerable part of patients of the expressed feeling of tiredness feet at walking. This complaint was at 87,0 % patients. Main principles and methods of diagnostics of disease are described, and also a new way is computed tomography scan, allowing to visualize all characteristic for deformation of infringement of anatomy of joints and bones of foot in the conditions of influence modeling on it orthostatic load. Authors come to the conclusion that EPVFD by cerebral palsy children’s possesses a number of prominent features which probably to reveal special receptions and diagnostics methods, and also it is necessary to consider for increase of efficiency of the complex surgical approach to treatment EPVFD at patients with cerebral palsy.Основываясь на данных литературы и собственных наблюдениях, авторы описывают особенности патогенеза эквино-плано-вальгусной деформации стоп (ЭПВДС) у больных с детским церебральным параличом (ДЦП), а также клинических проявлений заболевания, выявленных ими при обследовании 52 пациентов (79 стоп). В статье приведено ранее не описанное клиническое наблюдение - наличие у значительной части больных выраженного ощущения усталости в нижних конечностях при ходьбе. Данная жалоба имела место у 87,0% пациентов. Освещены основные принципы и методы диагностики заболевания, а также новый способ компьютерно-томографического обследования - функциональный, позволяющий визуализировать все характерные для деформации нарушения анатомии суставов и костей стопы в условиях моделирования воздействия на неё ортостатической нагрузки. Авторы делают вывод о том, что ЭПВДС при ДЦП обладает рядом характерных особенностей, которые возможно выявить специальными приёмами и методами диагностики, а также необходимо учитывать для повышения эффективности комплексного хирургического подхода к лечению ЭПВДС у пациентов с ДЦП
Change Spectrum Characteristics Modification of Films Deposited by Magnetron Sputtering with the Assistance of Argon Ions Beam
Thin aluminum films were prepared using the method of magnetron sputtering with and without argon ion beam assistance. The influence of argon ion beam on the reflectivity in the UV range and the structure of aluminum films was studied. The structure of the films was studied by transmission electron microscopy (TEM), X-ray diffractometry (XRD) and atomic-force microscope (AFM). The study has shown that the films deposed with the assistance of the argon ion beam have more significant microstresses associated with an increase of crystallites microstructure defects as compared to the films deposed without ion assistance. Comparison of the measured reflectivity of aluminum films deposed without and with the assistance of the ion beam has shown that the films characterized by a higher level of microstructure def ects have increased reflectivity in the UV range. The studies suggest that the defects of thin aluminum films crystal structure influence its optical properties
Influence irradiation argon ion SnO[2] on optical and electrical characteristics
Tin oxide in the form of films has been deposited by reactive magnetron sputtering on glass substrates a room temperature. Process was carried out in such mode when the deposited films were conductive. The deposited films were irradiated with argon ions. Have been studied happening at that the changes optical and electric properties of films. Have been investigated optical properties of films in the range of 300-1100 nanometers by means of photometry. For research structure of films was used the x-ray diffractometry. Diffractometric researches have shown that the films deposited on a substrate have crystal structure from shares of a quasicrystal phase and after influence of argon ions she completely became quasicrystal. It is established that change transmission of a film correlates with change her electric resistance. Average value transmission in the range of 380-1100 nanometers as well as the electric resistance of a film with growth of irradiation time increases to the values exceeding initial. At the same time at irradiation time ~ 13,2 sec. are observed their slight decrease. To this value of irradiation time there corresponds the minimum value of electric resistance and transmission films. Change of transmission coefficient correlates with change of surface resistance
Software for Regional Studies: Analysis of Parametrical Multicriteria Models
This paper describes an approach to analyzing how the balanced states of a multicriteria model depend on the values of exogenous parameters. It provides, consistent with the model criteria, an algorithm that chooses the optimal form of the Pareto set. As an example, the paper explains the use of the approach for a regional water-distribution model
Modeling Dynamic Systems of Variable Structure
Reliable software tools for mathematical modeling have been developed for simulation models but for constrained optimization models progress has been slower.
The following approach examines the possibility of working with large-scale mathematical models in a compact form permitting the direct analysis of input-output relations where information is transformed into a compressed mode (as opposed to aggregation procedures) without loss of accuracy.
The article also describes the approach when applied to discrete dynamic models
Impacts of Price Variations on the Balance of World Trade
A standard mathematical model of a trade market is considered and the concept of an acceptable state of the market is introduced, which takes into account the requirements of all the partners. To evaluate the "distance" between the acceptable and current states of the market, a special mathematical approach is developed. This approach has been found useful for correcting the price vector to bring the states closer together
Magnetron deposition of TCO films using ion beam
Thin films of tin oxide (TO) were deposited on the glass substrates at room temperature using reactive magnetron sputtering at various oxygen partial pressures. After the deposition the films were irradiated with argon ions beam. The change of the optical and electrical properties of the films depending on the irradiation time was studied. Films optical properties in the range of 300-1100 nm were investigated by photometry as well as their structural properties were studied using X-ray diffraction. Diffractometric research showed that the films, deposited on a substrate, have a crystal structure, and after argon ions irradiation they become quasi-crystalline (amorphous). It was found that the transmission increases proportionally with the irradiation time, but the surface resistance -disproportionally
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