In this paper, we propose a method to expand taxiways at large airports that shortens taxiing time and reduces costs. To ease congestion at airports, expanding taxiways is needed. But the exorbitant cost of expansion dictates the discreet selection of expanded taxiways. Determining expanded taxiways is a multilevel and multi-objective optimization problem containing 1-0 integer problem and routing problem. However, little research on this topic is available. In this paper, we propose an algorithm to calculate Pareto solutions applying a Multi-Objective Genetic Algorithm (MOGA) and Ant Colony Optimization (ACO). The proposed method is twice as accurate as other methods, and solutions calculated by proposed method are available when flight schedules are disturbed

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Ladders are used in various places and for a variety of applications such as to access attics in houses, warehouses, plants, and sewage systems. This is because ladders do not need to be installed in large spaces or specific structures, as opposed to stairs. However, humans carrying heavy loads when using a ladder are subject to fatigue and the risk of falling. Therefore, various robots that are capable of climbing ladders to transport loads have been studied. However, so far, these robots were not designed to fit various types of ladders and were built with complicated mechanisms. Hence, in this study, we have pursued the development of a robot that is capable of climbing various types of ladders using a simple link mechanism. We created an experimental unit and verified its performance through simulation experiments using a configurable ladder in various inclinations and using different loads.

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As material-handling equipment for unloading bulk materials such as iron ore and grain from vessels at harbor piers, continuous unloaders play an important role from the viewpoint of handling performance and environmental protection. Among the various types, belt conveyor-type unloaders are required to provide highly versatile handling performance covering low- to high-fluidity bulk materials. When low-fluidity bulk materials are handled, handling performance decreases and electric energy consumption increases because they do not flow easily into a scraping device. For a scraping device consisting of a horizontal screw and a rotary feeder, this paper proposes a cutting device in which multiple rotatable blades are arranged outside the scraping device. It also describes the basic structure and design guideline of the newly proposed cutting device to improve its low-fluidity bulk handling performance. Furthermore, the driving conditions of the cutting device are optimized, and the improvement of the handling performance is verified by experimental analyses using a model manufactured based on the design guideline. Cement, which is a typical low-fluidity bulk with a large angle of repose, is used for experiments. Low-fluidity bulk materials such as coal, converter slag and soybean meal having some different physical properties from those of cement, such as larger particle size, higher bulk density or higher moisture content, are also examined and discussed as materials for digging. The effect of each physical property on the handling performance, as well as the effect of the proposed device and its effectiveness toward stabilization, are also be clarified, including the basic design and method of optimization.

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For a full-sized wheelset with a hollow axle having machined artificial flaws at the fitting part (wheel seat), the variation of flaw echo heights due to cyclic rotating bending was investigated experimentally. The flaw echo heights were measured at different stages of cyclic loading with bending moment applied to the wheelset. The influence of the direction of bending moment as well as the incident direction of ultrasound on the echo-height variation was examined for each flaw. The flaw echo heights varied significantly during the cyclic loading and by the applied bending moment in spite that the size of each flaw was almost constant. The observed echo-height variations are discussed from the viewpoint of the change of contact condition of the axle-wheel interface by the fretting wear during the cyclic loading. The experimental results indicate that the progress of wear at the axle-wheel interface changes the ultrasound reflectivity and influences the measured echo heights. The wear at the interface can also amplify the effect of axis bending moment on the reflectivity and the echo heights. Some implications of the present finding to the ultrasonic testing of axles are also provided.

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This paper presents a novel design technique for high-speed trains using a multi-objective optimization method to balance plural aerodynamic properties. The technique involves the use of an evolutionary algorithm, a shape parameterization technique that uses B-spline curves and Coons patches, and a computational simulation that uses a Message Passing Interface. To demonstrate the capability of the method, a train nose is designed that has optimized aerodynamic drag and aerodynamic forces with respect to affecting other trains. A 10^th generation evolutionary calculation with 512 individuals was conducted, and physically reasonable Pareto solutions were successfully obtained.

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Wire rope and lashing belt are conveniently used in many places without knowing their tension. From the view point of safety, it is important to know the magnitude of their tension to avoid accident. We developed a tension meter for wire rope and lashing belt of a post-mountable type by which the magnitude of their tension in use can be evaluated. The tension meter twists a small part of the target and evaluates the torque required for a twist. So far, it has been unclear where to set a reference point for twist angle due to an internal friction of the wire rope. In this study, the reference point can be determined automatically by an electric control system so as to charge the same twist angle onto the wire rope. Regarding the lashing belt, there is no need to control the reference point as it has little internal friction. It was confirmed in the experiments that there was a linear relation between the tension and twisting torque in both wire rope and lashing belt. In addition, the internal friction of wire rope is discussed using a simple model.

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Recent years have seen increasing demand for the development of a car seat with an active headrest (AHR) that is expected as one of strong mechanisms to reduce neck injuries caused by rear-end collisions. This paper develops a mechanical impedance model-based computer simulator that can be used to analyze and design an effective AHR seat by means of the 7 criteria in line with the specifications of Euro-NCAP such as NIC and Nkm. The developed simulator can reproduce the dynamic behavior of a crash-test dummy (BioRID II) as measured in an actual rear-end collision test. The effectiveness of AHR originally developed to reduce neck injuries was quantitatively evaluated through a set of computer simulations. Furthermore, in order to improve the performance of the AHR seat, effects of the seat parameters such as the seat joint stiffness, the headrest position, and the viscoelastic parameters of the seat surface were investigated.

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