Advanced Materials Research Vols. 433-440

Abstract: The influence of artificial classroom light source’s colour temperature to students’ learning efficiency and physiology rhythm is the focus of this study. An experiment compares a subjects’ learning efficiency, asthenopia and brain fag under different luminance level of three typical colour temperatures from T5 fluorescent lamps and LED. Using comprehensive index ε and norm identification Ψ for quantitative evaluation and testing under different lighting environments, we determined the best colour temperature of two experimental light sources. We also determined the best combinations of illuminance value and the colour temperature that should be avoided in classroom lighting. Experiment shows that spectrum difference obviously effects comprehensive index ε and norm identification Ψ. For learning efficiency and health of people, there need to be improvement in the spectrum of fluorescent lamps and LEDs

Abstract: Optimization of phase offset for adjacent intersections is the key parameter regarding coordinated control of traffic signal for adjacent intersections, which decides the effect of the coordinated control for adjacent intersections. According to characters of saturated traffic flow of Chinese urban road, this thesis establishes a model for optimization of phase offset for adjacent interactions and finds a solution from such model by adopting genetic algorithm. The model is verified by actual traffic flow datum of two adjacent signal intersections on Changan Avenue. Then a comparison is made between the optimization result of such model and that of the existing mathematical method and SYNCHRO model, which indicates that the model established by this thesis can reduce the delay suffered by vehicles at the intersections and increase the traffic efficiency of the intersections.

Abstract: Based on an investigation of a typical village in northern China, we found that the “Four-in-One” ecological model for homes (sunlight greenhouse, pig house, toilet, and biogas digester) achieved benefits with regard to economy, society, energy use, and a cleaner environment once it was established. However, problems still impede the sustainable expansion of the model. The main problems are a relative lag in the management of biogas digesters, challenges in the production and distribution of farm products, home layout and piggery sanitation, competition for labor between agricultural production and outside work, and problems with land resources, investment and credit expenses, and infrastructure. In the end, some countermeasures are proposed, namely, perfecting the technical service system, strengthening farm training and improving agricultural production skills, establishing a stable distribution channel for marketing farm products and a suitable agriculture management model, selecting appropriate households for the Four-in-One model, and so on.

Abstract: Frequency modulation procedure is proposed to overcome the mode-mixing problem associated with the EMD method when processing signals with closely spaced frequencies. This procedure also provides the flexibility to start the realization of IMFs either from the high frequency end as does the original EMD or from the low frequency end when the signal contains unwanted high frequency components. The EMD procedure, under the circumstances, may behave as high pass, low pass or band pass/stop filters. The proposed method, assisted by the Hilbert-Huang transform on the governing equations, identifies the instantaneous stiffness and damping coefficients as functions of vibration amplitude of a nonlinear system. The effectiveness of the proposed method is verified by numerical simulation.

Abstract: Damage to simple beam bridge, continuous beam bridge, continuous rigid frame bridge and arch bridge is analyzed in Wenchuan, Tangshan and Yunnan earthquakes etc. The results show that seismic damage for the same bridge system has many common features, and seismic performance of different bridge system varies greatly. Fall, bearing sliding, beam displacement and collision between adjacent beams at expansion joints the is major earthquake damage for simply beam bridge. Seismic damage ratio and degree of continuous beam bridge is bigger than the simple support beam bridge. Earthquake damage of the continuous rigid frame bridge is obvious lightly in the close simple beam and continuous beam bridge. Seismic damage of arch bridge is more complex. Selection methods of reasonable aseismic system for the straight line bridge in seismic zone are proposed based on the analysis of earthquake damage and numerical analysis.

Abstract: The Discrete Element Method (DEM) was used to simulate cracks propagate in rocks subjected to uniaxial compressive stress. A DEM code was developed, and used to simulate the response of the continuum materials to loading. Rock samples with two initial cracks inclined at varying angles were simulated with the DEM code. The results were compared with those obtained from laboratory samples, and it was observed that the two results were consistent. This suggests that the DEM is a robust technique for the visualization of secondary cracks formations and propagations in rocks.

Abstract: Water system integration which aims on the bottleneck of the water network is the only effective method. Therefore, it is essential and significant to study the bottleneck identification of water networks. In this paper, the definition and fundamental characteristics of the bottleneck about flow rate in water network are given. The graph theory was engaged to identify the bottleneck of water network. A case study is used to show the method.

Abstract: Service-oriented software utilizes services as fundamental elements for developing applications that have the capability to autonomously modify their behavior at run-time in response to changes in their environment. While a few techniques have been developed to support the modeling and analysis of requirements for self-adaptive systems, limited attention has been paid to the description of service requirements and uncertainty in requirements of service-oriented software. In this paper, we propose a task solving strategy for requirement analysis and modeling framework as a fundamental of self-adaptation evolution. We introduce task solving strategy method for requirement analysis process; a context snapshot model to represent uncertainty in requirement with domain knowledge; goal-oriented context requirement to model user requirements and process-oriented context requirement to model service requirements; and finally, propose means-c-end analysis to relate user and service requirement with context condition.

Abstract: In order to test the characteristics of the telephone line, BER (Bit Error Rate) test is one of the most important aspects. The multi-frequency BER test is achieved using FPGA (Field Programmable Gate Array), MCU (Micro Controller Unit) and Modem chip. This design is able to exactly test the telephone line’s bit error whose frequency is between 1.2KHz and 160KHz. repeatedly experiments results show that this method is stable and reliable, and has important application values.

Abstract: A Vehicle routing model for logistics planning is developed in this paper. The model addresses the dynamic time-dependent transportation problem that needs to be solved repetitively at given time intervals during ongoing aid delivery. The model generates plans incorporating new requests for aid materials, new supplies and transportation means that become available during the current planning time horizon. The plan indicates the optimal mixed pick up and delivery schedules for vehicles within the considered planning time horizon as well as the optimal quantities and types of loads picked up and delivered on these routes. The mathematical model is a hybrid that integrates the multi-commodity network flow problem and the vehicle routing problem. Based on the analysis and calculation of an example, the results indicate that the model is effective and feasible.