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91.
Wood has long traditions as a building material, and is often used in construction elements, and as interior and exterior surfaces in the Nordic countries. In most applications, there are reaction to fire requirements to products used as surfaces, e.g. in escape routes and larger public spaces. Most wood products will therefore have to be treated with fire retardant (FR) agents to fulfil the strict requirements to properties connected to heat release and flame spread. Unfortunately, FR agents usually also increase the smoke production, as they cause a more incomplete combustion of the wood. The wood product manufacturers seek to find the optimal amount of FR additives where both heat release and smoke production in the classifying test are within the requirements given in the building regulations. This paper describes models for prediction of the European reaction to fire classes of wood products. The models are based on multivariate statistical analysis, and use test results from the cone calorimeter test as input. The presented models are, with very good precision, able to predict which Euroclass and additional smoke class a wood based product would obtain if it were to be tested in the single burning item test. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
92.
Optimal Locations of Groundwater Extractions in Coastal Aquifers 总被引:1,自引:0,他引:1
A regional water supply management model for coastal aquifers was developed. One of its outcomes is the definition of the
optimized locations for groundwater withdrawal. Such a tool permits the analysis of alternative plans for groundwater extraction
and the sustainable use of water resources in a coastal aquifer subject to saltwater intrusion. The principal components are
the evolutionary optimization and the analytical/numerical simulation models. The optimization technique looks for the best
well locations taking into consideration the economic results and the satisfaction of the societal water demand. However these
two concerns are conditioned by trying to control the saltwater intrusion, i.e., preserving the environmental equilibrium.
The simulation model uses the governing mathematical equations for groundwater movement to find the interface between freshwater
and saltwater. Because of the non-linearity in the system and the possibility of a jumping interface, a security distance
was defined. This is a controlling variable which can be set by the decision makers. The model was applied to a typical case
with interesting results. For example, diagrams showing the relationship between the location of the wells and the security
distance(s) are of importance to the managers. It was also crucial to have an understanding of the tradeoffs between groundwater
withdrawals, positions of the wells from the coast line, and the security distance. The model was also applied to a real case
in order to relate the extractions, distances and artificial recharge (not presented in this paper). 相似文献
93.
94.
Maciej W. Rogoziski 《Systems & Control Letters》1989,12(5):449-453
An optimal predictor is developed for a singular random process generated by a known system driven by a white noise sequence. The properties of the predictor are compared with those of the optimal predictor for a nonsingular random process. 相似文献
95.
节理岩体的代表单元集合体模型及弹性参数预测 总被引:8,自引:0,他引:8
本文明确提出了节理岩体“代表单元集合体”的概念和模型,通过对节理岩体的“代表单元集合体”进行数值模拟,研究了节理岩体的“代表单元集合体”的变形特性,建立了节理岩体的弹性模型,提出了预测节理岩体宏观等效弹性参数的计算机模拟方法,并将其应用于岩体工程稳定性分析中。 相似文献
96.
Keh-Shin Lii 《时间序列分析杂志》1985,6(3):153-169
Abstract. A distributed lag model with a rational transfer function is considered. We have demonstrated that the C -table can be used to determine the orders of the rational transfer function and the Padé table can be used to estimate the parameters of an identifiable transfer function. In case the model is not uniquely identified, the C -table reduces possible competing models to only a few for further examination. Padé approximant gives consistent initial values for possibly more efficient iterative procedures to estimate the coefficients of the identified model. Some asymptotic results on the estimation of the C -table and the Padé table are given. A few examples are presented to demonstrate the effectiveness of the method. 相似文献
97.
An approach to solving a linear interpolation problem in a fuzzy information space is proposed. Two different schemes of interpolation
are outlined: a heuristic one, based on the geometrical interpretation of operations, and an optimization one, based on the
expansion principle. The results obtained allow performing fuzzy linear prediction.
__________
Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 55–68, March–April 2006. 相似文献
98.
储层石蜡沉积预测技术研究与应用 总被引:1,自引:0,他引:1
在油田开发过程中 ,由于油藏温度、压力等条件的变化 ,高含蜡原油在近井带容易产生石蜡沉积 ,堵塞地层孔隙或裂缝 ,严重影响油田开采 ,尤其对于低渗油田 ,伤害特别严重。文中应用理想溶液理论、质量守恒和能量守恒等基本原理 ,建立更符合油田实际情况的油藏中石蜡沉积预测数学模型 ,开发一套方便实用的油藏中石蜡沉积预测软件系统FPOS1 0。在此基础上 ,应用室内实验数据和现场数据对吉林新民油田油井石蜡沉积情况进行预测和现场拟合 ,确定新民油田临界石蜡沉积半径为 2 5m ,快速、准确地为现场清防蜡措施提供理论依据。 相似文献
99.
100.
广义物质平衡计算在凝析气藏开采动态预测中的应用 总被引:1,自引:0,他引:1
从经济的角度考虑 ,对小型凝析气藏衰竭式开采动态的预测往往不必或不值得进行数值模拟研究。常规物质平衡 (黑油 )计算方法只局限于黑油和干气藏 ,应用于凝析气藏则存在很大的误差。Walsh提出的广义物质平衡计算方法 ,可用于包括黑油、干气藏、挥发油气藏和凝析气藏在内的所有油气藏。文中将一个小型凝析气藏衰竭式开采动态的数值模拟结果与广义物质平衡计算结果进行了对比 ,结果表明 ,Walsh方法简便、应用更广泛 ,可用于规模较小、不适合进行数值模拟研究的凝析气藏的现场开发优化。 相似文献