楼梯间内人流合并特性研究

探讨了楼梯间内人流合并的影响以及随着人员密度的变化,合流方向和楼梯间与大厅之间门开启与关闭状态对人流合并难易程度的影响。研究结果表明:(1)人员密度小时合流较容易;(2)如果加入人流与楼梯内人员疏散方向相同时,人流合并较容易;(3)门处于开启状态时,合流较容易。如果门处于关闭状态,人员的疏散速度将降低30%。     

Chemometric Amylose Modeling and Sample Selection for Global Calibration Using Artificial Neural Networks

Chemometric arnylose modeling for global calibration, using whole grain near infrared transmittance spectra andsample selection, was used in an artificial neural network (ANN), to assess the global and local models generated, based onsamples of newly bred Indica, Japonica and rice. Global sample sets had a wide range of sample variation for amylose content(0 to 25.9%). The local sample set, Japonica sample, had relatively low amylose content and a narrow sample variation(amylose; 12.3% to 21.0%). For sample selection the CENTER algorithm was applied to generate calibration, validation andstop sample sets. Spectral preprocessing was found to reduce the optimum number of partial least squares (PLS) componentsfor amylose content and thus enhance the robustness of the local calibration. The best model was found to be an ANN globalcalibration with spectral preprocessing; the next was a PLS global calibration using standard spectra. These results pose thequestion whether an ANN algorithm with spectral preprocessing could be developed for global and local calibration models orwhether PLS without spectral preprocessing should be developed for global calibration models. We suggest that global calibra-tion models incorporating an ANN may be used as a universal calibration model.     

Fabrication of Grain-Oriented Bi2WO6 Ceramics

Grain-oriented Bi₂WO₆ ceramics were fabricated by normal sintering techniques. Platelike crystallites were initially synthesized by a fused salt process using an NaCl-KCI melt. When calcined at <800°C, the Bi₂WO₆ crystallites are 3∼5 μ m in size and, at >850°C, =100 μm. After dissolving away the salt matrix, the Bi₂WO₆ particles were mixed with an organic binder and tapecast to align the platelike crystallites. Large particles were easily oriented by tapecasting but the sinterability of the tape was poor. Preferred orientation of small particles was increased by tapecasting and grain growth during sintering further improves the degree of orientation. Sintering above the 950°C phase transition, however, results in discontinuous grain growth and low densities. Optimum conditions for obtaining highly oriented ceramics with high density occur at sintering temperatures of 900°C using fine-grained powders which yield orientation factors of =0.88 and densities of 94% theoretical.     

Phase Diagram of the System BaO-Fe2O3

The phase diagram of the system BaO-Fe₂0₃ was determined by X-ray diffraction, melting-point measurement, and microscopic methods. Since the reduction of Fe³⁺ to Fe²⁺ was observed by chemical analysis in the samples heated at high temperature, especially in molten samples, the samples were heated at 1 atmosphere pressure of oxygen in the temperature region in which the liquid was in equilibrium; 1 atmosphere pressure of oxygen was su5cient to restrain the reduction of Fe³⁺. In the temperature region of solid-solid equilibrium, the dissociation was not observed even when the samples were heated in air. BaO - 6Fe₂O₃ formed a solid solution with BaO.Fe₂0₃. The BaO:Fe₂0₃ ratio of the solid solution was BaO.4.5Fe₂0₃ at 1350°C. and BaO. 5.0Fe₂0_a at 800°C. The precipitation micro-structures of each primary solid solution were observed.     

Estimation of air pollutant concentrations by the Galerkin finite element method

This paper is concerned with the estimation of air pollutant concentrations by solving the advection-diffusion equation using the Galerkin finite element method. The physical properties denoting the transport arid diffusion of the air pollution are assumed to be expressed by the two-dimensional advection-diffusion equation where the height of the stack is low and the vertical diffusion is small. The distributions of wind velocities and background concentrations are estimated using an interpolation method based on the observed data at monitoring stations. The Galerkin finite element method estimates the temporal and spatial distributions of air pollutant concentrations by solving the advection-diffusion equation. The estimation experiment of sulphur dioxide concentrations is carried out over the industrial area of Tokushima Prefecture, Japan, and the numerical results indicate the effectiveness of the proposed, method.     

An Investigation of Size‐Reduction Effects in High Power Density Boost Converters with a Magnetic Coupling

The dc–dc converter using integrated magnetic components that may achieve high power density has gained attention in environmentally friendly cars such as electric vehicles and hybrid electric vehicles. This paper focused on interleaved boost converters using close‐coupled inductors (CCIs) and loose‐coupled inductors (LCIs) that are the integrated magnetic components. Following, detailed electromagnetically analysis for these circuit types were conducted in order to calculate volume of inductors and capacitors that are occupied the large part of space in the converters. The total volume of inductors and capacitors in these circuits were demonstrated clearly through comparison with conventional circuits such as an interleaved boost converter and a single‐phase boost converter. As a result, it became clear that interleaved boost converter using LCIs was effective for miniaturization of total volume. Furthermore, duty ratio of the minimum volume of CCI method is different from the duty ratio of the minimum volume of LCI method.     

Evaluation of fibre bridging stress of short fatigue cracks in SCS-6/Ti-15-3 composite

Single‐edge notched specimens of a unidirectional SiC long fibre reinforced titanium alloy, were fatigued under four point bending. The propagation behaviour of short fatigue cracks from a notch was observed on the basis of the effects of fibre bridging. The branched fatigue cracks were initiated from the notch root. The fatigue cracks propagated only in the matrix and without fibre breakage. The crack propagation rate decreased with crack extension due to the crack bridging by reinforced fibres. After fatigue testing the loading and residual stresses in the reinforced fibres were measured for the arrested cracks by the X‐ray diffraction method. The longitudinal stresses in the reinforced fibres were measured using high spatial resolution synchrotron radiation. A stress map around the fatigue cracks was then successfully constructed. The longitudinal stress decreased linearly with increasing distance from a location adjacent to the wake of the matrix crack. This region of decreasing stress corresponded to the debonding area between the fibre and the matrix. The interfacial frictional stress between the matrix and the fibre could be determined from the fibre stresses. The bridging stress on the crack wake was also measured as a function of a distance from a notch root. The threshold stress intensity factor range, corrected on the basis of the shielding stress, was similar to the propagation behaviour of the monolithic matrix. Hence the main factor influencing the shielding effect in composites is fibre bridging.     

On a sub-optimal control scheme of linear stochastic systems with inaccurate models†

This paper presents a problem of deriving a sub-optimal control scheme of linear, discrete-time systems with inaccurate models. The sub-optimal control policy is determined as a linear combination of an estimate of the state when the expected value of a quadratic performance index is to be minimized. The estimate obtained from the sub-optimal filtering equations is modified by a hypothesis test of statistics for the innovation sequence. The numerical results of digital simulation indicate that this approach improves the system performance.     

Sliding mode control and a variable structure system observer as a dual problem for systems with non-linear uncertainties

Sliding mode control is described for continuous-time systems with uncertain nonlinear elements, in which the euclidean norm of the unknown element is bounded by a known value. For a case of complete state information, we first consider a sliding mode controller consisting of three parts: a linear state feedback control, an equivalent input and a min-max control. It is then shown that the present attractiveness condition is simpler than that for a case without using the concept of equivalent input. We next derive a variable structure system (VSS) observer as a completely dual form to the sliding mode controller. The attractiveness condition is also simpler than that for a case an equivalent term is not used, but a more severe assumption is required to solve such a VSS observer. Finally, we discuss a case of incomplete state information by applying the VSS observer.