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Evaluation of disaster evacuation routes is a key to success in disaster management efforts and strategies, especially in disaster-prone areas such as Indonesia. Ability to evacuate many people in a short time is needed to minimize casualties. Thus, a computational simulation method is needed to assist in making a rescue strategy. Agent-based modelling (ABM) approach makes it possible to know what interactions occur during the evacuation process, both in the form of interactions between individuals and individual interactions with their environment. This study examines the dynamics of behavior, interaction mechanism between agents and environment, as well as knowing the evacuation time required by this interaction mechanism and producing improvement scenarios of the existing system. The research begins by collecting spatial characteristics data and initial behavior through questionnaires, literature, and direct observation. Model was built using Netlogo 6.2.0 software. Simulation results were analyzed by design of experiment (DOE) on the evacuation process in BINUS Online learning Room with four types of agents, with a composition of 30% leader, 35% follower, 26% independent, and 9% under table agent. Results showed that gender factors had a significant effect on evacuation time, while behavior factors had no significant effect. [ABSTRACT FROM AUTHOR]

During military expeditions, troops are often encountered with obstacles like crevasses, large gaps, canals etc. To set up conventional bridges or other crossing techniques are time taking and cumbersome which may also require the carriage of heavy stores. To cross a gap of up to 5 meters, very heavy logistics is required. The main idea for developing this man-pack bridge, which can be carried by one individual, is to provide an expediting solution and reduce logistic requirements by heavy margins. The concept of the Da-Vinci Bridge is adopted in this study for the design and simulation of the model proposed. Initially, a 3D model of a simple Da-Vinci bridge is designed and force analysis is conducted keeping in mind the optimum weight, optimum length and other factors. After obtaining the results, different methods and several iterations have been done to make this bridge portable. Finally, a telescopic mechanism is proposed based on the idea from the portable ladders used by the lineman while operating on the electric pole. The proposed design would not only be able to help soldiers but it can also be used in villages for easy movement. [ABSTRACT FROM AUTHOR]

The aircraft sheet metal part is the important component of aircraft structures and the rubber forming is one of the main forming method for aircraft sheet metal part, the prediction of initial blank sheet shape is a difficult problem for rubber forming. A fast prediction method for initial blank outline of rubber forming based on one-step inverse forming is proposed. Firstly, the designed sheet metal part is treated as the final configuration. Then the quick reverse simulation is carried out to obtain the initial blank outline by the one-step inverse analysis. Finally, the outline from the above method is applied into real rubber forming manufacture. The experimental results are well demonstrated that this method is an effective way to predict the initial blank shape for rubber forming process. [ABSTRACT FROM AUTHOR]

Cosmogenic 11C is produced in-situ by atmospheric muons and forms the main background for the measurement of solar pep- and CNO-neutrinos. However, FLUKA simulations show that the majority of 11C is accompanied by a free neutron in the final state, thus allowing for an efficient tagging method, the so-called Three-Fold Coincidence technique. The technique and its first applications on Borexino data are presented. [ABSTRACT FROM AUTHOR]

Recently, considerable attention has been paid for the many kinds of flexible production processes. Most concerned one is the incremental sheet metal forming (ISMF) process, which does not require any high capacity press machine and a set of dies with specified shape for the product. ISMF process apparatus requires a traveling tool with simple shape and a holder which holds the sheet stationary at its periphery. In this research, spring-back and its effect on dimensional precision of ISMF process has been studied. The influence of process parameters such as: vertical step size (ν), sheet thickness (t), tool diameter (d), feed rate (f) and spindle speed (n) have been investigated. A series of experimental tests have been implemented for a straight groove bead-shape part made of aluminum sheets (Al 1050-O). In first section, a reliable statistical analysis has been carried out to extract the importance of each parameter. The obtained model permits to select appropriate process parameters to reduce spring-back effectively. In second section, simulation process has been implemented by FEM software. In final, experimental results confirm the results of simulation and comparisons between experimental and simulation results of spring-back have shown good agreement. [ABSTRACT FROM AUTHOR]

The experimental observation of a quadrupole pattern in the 'out-of-plane' field By is usually interpreted as a tell-tale sign of Hall MHD mediated magnetic reconnection in the vicinity of a reconnecting X-point. In contrast to these conventional expectations, it is shown By means of analytical equations describing the generation of By that quadrupole structure can be formed even in the absence of Hall effects. In general, By can be generated due to inhomogeneous ion flow, inhomogeneous current (Hall effect), or terms proportional to a pre-existing By. This prediction is validated in a 3D global MHD simulation where it is shown that vortex flows at the dayside magnetopause lead to formation of a finite By even in the absence of a pre-existing IMF By. The generated field is shown to have a quadrupolar pattern in By with peak amplitude ∼0.5 of the total field. Similar vortex flows are also observed in 3D global hybrid simulations but the resulting By structure in this case is a combination of the Hall effects and the inhomogeneous ion flows. Thus special care must be taken in using observations of quadrupole By in satellite and experiments to infer information about its particular generation mechanism or attributing it to the Hall MHD reconnection regime. [ABSTRACT FROM AUTHOR]

Despite of today’s steady and continuing improvement of computation power, effective use of complex and computational intensive engineering analysis and simulation codes in design optimization remains a challenge. In this work, a new global optimization algorithm, namely Mixed Surrogate Models and Design Space Elimination Search (MSMDSES), is introduced. The approach divides the field of interest into several unimodal regions; identify and rank the regions that likely contain the global minimum; fits a Radial Basis function and Quadratic Response Surface model over each promising region with additional design experiments data points using Latin Hypercube designs; identifies its minimum and removes the processed region; and moves to the next most promising region until all regions are processed and the global optimum is identified. The new algorithm was tested using several benchmark problems for global optimization and compared with several widely used region elimination and space exploration global optimization algorithms, showing reduced computation efforts, robust performance and comparable search accuracy, making the new method an excellent tool for computation intensive, computer analysis/simulation based global design optimization problems. [ABSTRACT FROM AUTHOR]

In the forging process of complex 2D and 3D parts, multiple intermediate shapes must be used to control metal flow and/or material distribution to ensure proper filling of the finisher die. A systematic method to design an intermediate shape (known as a blocker or a preform) is especially critical for a successful outcome in the forging process. The quality of the blocker/preform design has been highly dependent upon the designer’s experience. In order to minimize and ultimately remove the “experience” dependency from the design process, the objective of the current work is to investigate and develop a reliable and practical procedure to systematically carry out the blocker/preform design task. This paper summarizes the overall methodology used for both 2D and 3D preform design problems. Examples are given to demonstrate the capability of the methodology. Sensitivity analysis is used in 2D to achieve the optimal design. The objective function minimizes the variation of strain distribution within the forged component and under-filing and folding are not allowed. A procedure to couple both the filtering technique by using Fourier transform and the FEM was developed for 3D. A blocker/preform design for a complex rib-web type model was achieved by iterating through the filtering method and the FEM simulation. In this example, an under-filing problem was eliminated. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

An explicit 3D software “FEAPIM” has been developed at LMARC to perform efficiently the injection simulation to predict and simulate a segregation effect in the mixture flows during MIM, and segregation is the most defect in metal injection molding. In order to reduce it on suggest optimization strategy.A cost function is first defined to account it, and optimization strategy has been developed using the Design Of Experiments (DOE) to find the most influent parameters. Four sensitive parameters are found : Powder volume fraction, Interaction coefficient, Powder density, and Binder density. In order to decrease the computational cost associated to optimization, the response surface, using the Moving Least Square Approximation (MLSA), is used to approximate the cost function. Then a genetic algorithm is coupled with this response surface to obtain the optimal values in reasonable time. The optimization strategy proposed in this paper has been applied to the tensile test. Optimization results are compared to experimental ones and a good agreement is found. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

This study focused on manufacture of high-aspect-ratio optical fiber ferrules by micro thermoplastic injection molding technique. In the past, the optical fiber connectors were produced by ceramic powder injection molding and subsequent precision grinding process. In this work, plastic micro injection molding technique was attempted to manufacture net-shaped products at once. Each ferrule has a micro through hole in the center. The hole’s diameter is 125±1μm, and its length is 9mm. During micro molding, how to keep the micro core pin at the center becomes a critical issue. In this work, a guiding slide system is introduced to hold the micro pin continuously. And the slide movement was controlled by a spring behind it. Such a guiding system can help reduce mis-alignment of the micro core pin and increase its life time. Taguchi’s design of experiment was used to evaluate the effects of processing parameters on final properties. Experimental results reveal that the higher the spring force, the larger the product weight and the lower the shrinkage. In order to obtain better uniformity of diameters at different locations, diameters at three locations were measured. Measured data showed the shrinkage of diameter in the middle is greater than those at two ends. It is because the two ends cooled faster than the center region. This can be improved by applying higher mold temperature or appropriate holding pressure or holding time. The new design concept can be applied in molding micro tubes, especially for the high aspect ratio cases. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

The article discusses the concept and principles of the development of complex molecular and biomaterial systems. Experts have been able to develop tools and learn strategies to the practical computational investigation of reactive processes in the ground and excited states of molecular systems of increasing size and complexity. With this, impressive advances in the computational techniques and methods have occurred.

Optimisation of the milling process is often based on simplified models of the cutting forces generated during the machining operations. Most of the simulation algorithms use simple linear relationship between cutting forces and the undeformed section of the chip. The coefficients of those models (often called specific pressure) are considered to be constant with respect to the other parameters. The variation of those coefficients as a function of the cutting speed or the chip thickness has been experimentally observed but most of the authors neglect this effect for simplicity sake. This paper proposes an experimental method to take the variation of these cutting coefficients with respect to cutting parameters into account. Analysis of variance is performed to identify the significant parameters. A design of experiment approach is followed to select the adequate experimental points to ensure maximal precision with the minimal number of machining tests. [ABSTRACT FROM AUTHOR]