For casting small polymer parts (10 mm cube), with the aim to achieve footprint-saving, simple operation, energy conservation, the realization of a small-desktop injection molding machine. To produce the machine is improved to the new system disk from the conventional method of screw plasticizing process, its performance was evaluated injection. For using small pellets and removing bubbles designed small-sized disk. By modifying the hopper shape, the rotor shape and the stator mechanism, proper running condition was successful compression molding. It was able to automatically and continuously extrude. As a result of ejecting polymer, a possibility of realizing a small-desktop disk-type injection molding machine was obtained.

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Titanium is used in many industry fields because of its high rigidity and harmlessness to human body. Titanium coloring by laser irradiation has attracted interests, however it has not been widely used in industry because it is difficult to control hue. In this research, the coloring mechanism of titanium oxide layers which is generated by pulsed Nd:YVO4 laser (wave length λ=1064nm) treatment in air was discussed. A series of colors were obtained by changing the laser irradiation parameter. By evaluating the obtained color, it is found that the brightness is related with the surface roughness. In addition, by microscope observation, it is found that the surface of the titanium and the area of titanium oxide layers after laser irradiation are affected by oscillation frequency. As the results, both the laser irradiation parameters and the surface state of titanium have to be considered for control the color.

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The purpose of this research is to develop a vibration monitoring system for wind turbine blades. The system is to estimate the deflection of any arbitrary point on the blade by measuring dynamic strain at a few points near its root connected with rotor hub. The estimation algorithm is based on the experimental modal analysis and adopts a few lower modes. The basic experiments are conducted using a 300W small-scaled wind turbine to investigate the feasibility of the algorithm. A few strain gages are tightly glued on the inner side of a blade skin near its root. A sensor network is installed in the center of the rotor. The vibration is measured using the strain gages under the rotating condition of the blades driven by wind, and the vibration of the tip is estimated. The validation of the estimation is discussed based on both theoretical investigation and the experimental result.

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In case of input location varying machine such as planetary gear transmission, the noise is varied in function of rotating angle. The time domain Transfer Path Analysis can be utilized to investigate the path contribution. A simple model is used to verify and apply the path modification for vibration and noise reduction.

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More and more wind turbines (WTs in brief below) are being constructed and operated worldwide in these years. However, various accidents happen in WTs during operation. For one thing, collisions between towers and blades due to excessive blade vibration have been reported to occur. To prevent such accidents, we proposed a kind of blade vibration monitoring system and applied to a blade, whose length is approximately 37 meters, of a 1.5MW WT. The system is composed of some sensors and a wireless communication device, and the components are embedded at an inner place near the root of the blade. It enables to estimate vibration amplitude of the blade's tip for practical level based on modal analysis. This paper presents the principles of the system and the result of on-site test on operation, and additionally clarifies the vibration phenomenon by tower shadow effect.

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The vibration power generator is strongly desired to provide distributed local power supply. But the problem is small power at off resonance frequency. Therefore multiple degree of freedom vibration power generator is designed to improve generation efficiency for wider frequency range.

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Wind energy is attracting attention around the world as renewable energy and wind energy industry continues growing at an impressive rate. In Japanese wind energy industry vibration fatigue of the blade has become a type of serious problems because of the intense pulsation of wind speed. This paper presents a numerical method for blade vibration analysis in unsteady flow. The calculation is carried out in two steps. The first step is aerodynamic simulation based on blade element momentum (BEM) theory. The second step is structural simulation based on modal analysis. The influence of wind turbine tower to blades at crossing in the front, which is called "tower shadow effect", is investigated by the numerical analysis.

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An Energy-Regenerative MR damper was designed and fabricated. The damping and energy regenerating performance were investigated experimentally. Magneto-rheological (MR) Grease is known as a kind of smart material witch can change its rheological property by magnetic field. MR damper is a kind of oil damper which uses MR Grease as working oil. Usually, this type of damper has an electric coil, and applying current to it, magnetic circuit is formed and the damping property of MR damper can be changed. This time, an energy regenerating mechanism which is composed of a ball screw system and a generator was attached to MR damper and some electromagnetic methods were introduced. As the result of experiment, the damping force and regenerated voltage were measured and the performance of this device was investigated.

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In this paper focuses on the laminated sound-proof multi-layer structures for use in an automobile to achieve design optimization. Damping sheet and sound-proof materials are widely used in multi-layered structures to suppress vibration and noise in automobiles. The number of combinations of multi-layered structure are too enormous to calculate all combinations. Therefore, this paper calculates efficiently for lighter and better sound proofing efficiency multi-layered structures than existing multi-layered structures. Finite element method to agree quantitatively with the experimental results is used to calculate vibration, but it takes a very long time to calculate the analysis results. We employ transfer matrix method that is shorter time than finite element method. In transfer matrix method, multi-layered structures are expressed by transfer matrix using Biot's model to analyze efficiently. Lighter and better sound proofing efficiency multi-layered structures were efficiently calculated by using a multi-objective genetic algorithm.

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Recently multi-axial precise positioning technologies have played an important role for a development of portable devices. For example, we need the technologies for assembling tiny chip parts into cell phone, laptop PC, and MEMS device. We also need them for testing integrated circuits and nanometer-sized-materials and bio-cell processing. Multi-axial linear stages inside conventional surface mounting technology (SMT) instruments are over 100kg. They are much larger and heavier than tiny chip parts of 1mg. Those instruments generate big vibrations to other precise instruments around them because of their high-inertia. In those 10 years, we have developed holonomic and omnidirectional mobile mechanism which moves inchworm principle actuated by several piezoelectric actuators and a pair of electromagnets. In this paper, we evaluate vibration property of the mechanism and discuss theoretical framework of an elimination of influence from outer vibration.

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The approximate analytical method using the maximum entropy method (MEM) is proposed to estimate the stationary probability density function of asymmetric nonlinear systems subjected to non-white random excitation. The MEM is often used to estimate the response distribution of nonlinear systems subjected to Gaussian white noise. In order to obtain the response distribution, the moment equations are used as the constraint conditions on the MEM. However, in the case of non-white random excitation, the term of the cross-correlation between the excitation and the response appears in the moment equation. Generally, this term is not able to be calculated when nonlinear systems are subjected to non-white excitation. In the proposed method, the equivalent linearization technique is applied to calculate the cross-correlation approximately. Using the method, the stationary response probability density functions of an asymmetric nonlinear system subjected to non-white excitation which has the exponentially decaying correlation function are estimated. To indicate the effectiveness of the method, the results are compared with those of Monte Carlo simulation.

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Response characteristics of a single-degree-of-freedom linear system subjected to narrow-band non-Gaussian random excitation are investigated. The excitation is assumed to be a stationary stochastic process characterized by the non-Gaussian probability density and the narrow-band power spectrum. As the probability density of the excitation, bimodal distribution and Laplace distribution are used. Monte Carlo simulations are carried out to obtain the stationary response distributions. The response characteristics are discussed by using the maximum value of the absolute value of the cross-correlation function between the excitation and the response. It is shown that the shape of the stationary response distributions varies depending on the maximum value of the cross-correlation function.

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Many studies have demonstrated the effectiveness of particle dampers in a single degree-of-freedom system. Particle dampers is currency used for structural damping applications, in magnetic resonance instruments, space shuttle main engines, railway vehicle bogies and so on. However, the investigation on particle dampers in two degree-of-freedom systems have not yet been completed. In this study, the damping efficiency of particle dampers in a two degree of freedom system under sinusoidal excitation was investigation. The effect of mass ratio, particle size and cavity dimensions on the damping performance was investigated. In the theoretical analysis, the discrete element method (DEM) was used.

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There is an impact damper, which consists of an impactor, a container, and walls. The vibration of primary system is reduced by collision between an impactor and walls. In this study, the authors deal with the case of two impactors and pay attention to setting patterns of containers which enclose two impactors. They refer to that as the double impact dampers. Then, they perform shaking test for the structure model and examine the setting pattern with the maximum damping effect from the view point of vibration energy of primary system and sound pressure of collision between two impactors and walls.

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In recent years, the vibration system which has negative mass characteristics, called meta-material, attracts attention. This system consists of two single-degree-of-freedom system. This two-degree-of-freedom system can be represented to an equivalent single-degree-of-freedom system. In case of the subsystem without a damping, the effective mass of this equivalent system has the negative mass characteristics. When the damping of the system is taken into consideration, the effects of the damping on these negative mass characteristics are not clarified. The effects of damping upon characteristic of vibration system with negative effective mass are investigated. The condition of the negative mass characteristics is derived with a damped subsystem. The effects of the damping of subsystem on the negative mass characteristics are discussed.

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In this study, analysis is conducted on the behavior of an electromagnetic reciprocating vibratory swing compressor. The governing equation of the swing compressor is derived considering the electromagnetic coupling between the vibrations of a spring-piston system and electric circuit consists of a coil and a resistance. The pressure of refrigerant acts on the piston is also considered. Effects of parameters, such as mechanical damping and pressure of refrigrant on the performance of the compressor is discussed numerically in detail.

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Gears of automatic transmissions are shifted with friction force of a multiplate wet clutch. In the wet friction clutch, undesirable vibration and noise can occur when gears are shifted. In this study, we conducted experiments on vibration and noise to understand the generation mechanism in a wet clutch system. An experimental setup was designed to realize a system composed of transmitting shaft and clutch drum to fix a separator plate (S/P) in a wet friction clutch. The results to be obtained are as follows: (1) The S/P acceleration waveform like damped free vibration of around 146 Hz and the sudden increase of sound pressure of around 950 Hz were observed just after the contact state between the S/P and the F/P transited from stick to slip. (2) Vibration component of around 950 Hz was observed in the S/P radial direction.

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Recently, cooling fans have been commonly used with inverter to optimize operating point of air volume for energy savings. But it increases abrasive vibration radiated noise caused by exciting force of PWM control, and that fundamental frequency is the same as career frequency of inverter. The purpose of this study is to reduce vibration radiated noise of impeller by using vibration mode shape that has low acoustic emission.

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In recent years, buildings and houses are remarkable damaged by large scale earthquakes all over the world. And also, Japan is one of the countries that is occurring many earthquake. Therefore, the study to protect buildings and houses from collapse caused by earthquake has been conducted. In our laboratory, the small size spherical damper for houses was developed. This damper has the damping effect against 3dimensions. In this paper, the damping effect due to change of mass and volume of the spherical vibrator is confirmed. As a results diameter 32mm sphere damper with 50000[cSt] or 30000[cSt] silicon oil has the most damping effect. Differencing of damping effect changed by sphere of material mass is not confirmed.

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In order to investigate effects of marble plate shape on the natural frequency and damping ratio, vibration analysis of the small base isolation system was done. The increase in the natural frequency can be suppressed by matching the radius of curvature of the concave spherical surface and the marble. Furthermore, mounting some rivets at the surface of marble bearing or boring the surface of marble bearing, the damping ratio of this system in all cases indicates a little bit lower. It is possible to adjust the natural frequency and damping ratio of the system by changing the marble shape.

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In this paper, a motion planning scheme of a variable stiffness manipulator able to vary stiffness of shoulder joint by changing effective length of leaf spring which has been designed and built to perform a stability sensing of robot's surrounding objects with unpredictable mechanical properties by touching them, was proposed. An analysis scheme to calculate an external force exerted on end-effector by using measured angular displacement and given stiffness while subtracting gravitational force is firstly explained. Subsequently, a motion planning scheme to determine how to configure the manipulator is proposed on purpose to widen dynamic range of stiffness by changing the length of a moment arm between the end-effector and the joint with variable stiffness mechanism. The scheme utilizes this principle to selectively achieve high measurement sensitivity and large output force. Capability of a prototype robot to achieve wide range stiffness and effectiveness of the scheme are experimentally demonstrated.

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This paper describes fabrication of a cylinder type gas-liquid phase change actuator. Pneumatic actuator is used for a endoscopic surgery support robot. However pneumatic actuator have some faults. Its peripheral equipment is large and makes oscillation and electromagnetic noise. These adversely affect medical equipments. We think that new actuator which does not have those faults is necessary. We suggest a gas-liquid phase change actuator. It is an actuator which big power is got from in the small size. And it can work only with DC power supply such as dry cells. Its device is small and has a small influence to give medical equipments. We fabricated a cylinder type gas-liquid phase change actuator. We identified its mechanical characteristics and operation principle.

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In recent years, ultra-compact electric vehicles have been increasingly demanded because of environmental issues and the aging of the society. We aim to design and manufacture a Steer-by-Wire System to control the driver's seat when the driver's entire body is on the active seat suspension system. In addition, we also aim to develop an intelligent seat that can provide an optimal driving environment in accordance with changing conditions by monitoring the driver's physical condition by the system on the basis of various biological signals. In this study, we carry out a driving experiment of an ultra-compact electric vehicle with the SBWS to evaluate changes in the operational feel perceived by drivers by means of a questionnaire on subjective evaluation or surface EMG, and collect basic data used to improve the operability.

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This paper proposed a kind of tendon driven robot arm structure using ball joints and parallelogram. Proposed mechanism can realize slide and twist motion with simple structure. In the tendon driven mechanism, artificial muscles are developed which uses both the SMA actuators and the elastica. In order to control the structure, we use the internal force term at the desired position. Concept of the controller was based on the analysis of the human motion as the cascade control strategy. The proposed mechanism can realize a force controller of the muscles that uses both the discrete-time and the continuous-time controller. Then, we can develop such as an impedance controller or various controllers depending on the desired tasks.

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The goal of this study is to propose a concept of "Man-powered robotics," a design methodology for an intelligent robotic system powered by human's motion. In the system, the servo control of robotic joints is performed by controlling transmitted torque of the power given by human's motion. In this paper, for the developed prototype of the human-powered personal mobility KMM74, inverted pendulum attitude control method is described. The authors modeled the passenger and vehicle body as a rigid body, and designed the controller based on the linear quadratic regulator. The effectiveness of proposed method is confirmed through the simulation results.

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We have proposed a passive-type walking support system equipped with a lift device. The lift device has a constant force spring and a powder brake. The constant force spring is used in order to provide a patient with partial body weight support. The powder brake is used in order to prevent the patient from falling down. This walking support system is intrinsically safe, because this system consists of only passive components with no active actuators. The system normally provides the patient with partial body weight support. If the patient is likely to fall down, the system prevents the fall by applying impedance control to the powder brake. In this paper, we discuss the effectiveness of the impedance control from simulation results and experimental results.

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Customer behavior in a store was predicted by using Cellular Automata. Customers move around in a store depending on the layout of items, so the layouts of a store have large effect on amount of sales. But in fact, it is difficult for retailers to design the best layout. In a store, there are large amount of items which influence customers. Customer behavior can be considered as one of Complex Systems. Therefore we modeled it by using Cellular Automata (CA). CA is an useful modeling method for Complex Systems. In CA algorithm, local neighbor rules are defined as interaction of elements which compose the phenomena. By using CA, we modeled the relationships between customers and items. In the simulation, purchase history was also considered by using past purchase data which are called POS(Point of sales) data. As a result, the customer movement depending on the layout of items was predicted.

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In previous study it was confirmed that changing grip position counteracts drivers' maintenance of appropriate steering angle. Therefore, we developed the bar type steering system with low steering gear ratio. The difficulty of steering operation with low steering gear ratio at high speed was improved by adjusting steering reaction of bar type steering. We designed reactive torque control system to improve maneuverability by using driving simulator. Vehicle reactions were measured when vehicle applied side wind disturbance. As result high anti-disturbance was got with the bar type steeling in comparison with the steering wheel. Here, we report the anti-disturbance of bar type steering in high speed range.

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Safety is one of the most important issues in human-friendly robots. We have proposed a velocity and contact force-based safety device for human-friendly robots and developed a wheeled mobile robot equipped with the safety devices. The safety device consists of only passive components without actuators, controllers, or batteries. The safety device has the "velocity detection mechanism", the "contact force detection mechanism", and the "switch-off and shaft-lock mechanism". However, the contact force detection mechanism may resonate with a robot vibration when the robot moves on a rough surface, because the mechanism has a plate, and two springs, that is, the mechanism is a mass-spring system. In this paper, we firstly review the robot with the safety devices. Secondly, we analyze the frequency response of the contact force detection mechanism. Thirdly, we propose a method to prevent the contact force detection mechanism from resonating with the robot vibration. Finally, we present experimental results to verify the usefulness of the proposed method.

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Safety is one of the most important issues in robot suits. We have developed a robot suit with two hardware-based safety devices - the "velocity-based safety device" and the "torque-based safety device". The robot suit assists a patient's knee joint. The velocity-based safety device switches off the motor if it detects unexpected high joint angular velocity. Similarly, the torque-based safety device switches off the motor if it detects unexpected high joint torque. The safety devices can work even when the computer breaks down, because they consist of only passive mechanical components without actuators, controllers, or batteries. In this paper, we design a new robot suit with hardware-based safety devices which is more compact than the previous one.

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This paper presented a fabrication of rehabilitation glove driven by pneumatic actuators. When damaging a finger, it's difficult to take back usual movement. The rehabilitation added to the symptom is needed. We propose the new gloves with which rehabilitation of a hand is supported. A glove for rehabilitation is driven by pneumatic bellows actuators. We confirmed to the fabricated glove are able to move winding and extension motions.

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An inspection of the large intestine is very effective in order to prevent the large intestine cancer. A fiberscope is excellent for the inspection of the large intestine. Many microrobots that can move in the large intestine have been proposed by several research groups. The actual large intestine in our human body is flexible and has very severe bending curve at the sigmoid. We propose a new microrobot that can surely move in the large intestine in the human body. We use six rubber bellows in series. Two outer rubber bellows actuators are provided eight bulging rubber sheets. These are called as the braking mechanism. The moving mechanism moves the microrobot by stretching and shrinking. Three rubber bellows are arranged after the braking mechanism in a triangle condition. The microrobot has been confirmed to move from the anus to the cecum in the artificial human's large intestine model for the freshman doctor's inspection training using the fiberscope.

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We are developing the small electric car for the practical use in the indoor facilities such as large supermarkets. Large commercial facilities increase at the same time as aging advances, therefore the demand for motor car to use indoors increases now. But the commercial electric car carries large battery and many functions to use it outdoors. Therefore size is big and becomes expensive, and the deployment to indoor facilities becomes difficult. Therefore we develop the inexpensive and compact electric car which reduced power consumption than a commercial motor car. We have done an improvement toward currently in practical use. We do a report of the current stage in this document.

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This study is intended to make a report on the design and development of work-assisted robot that aims to automate tasks such as book transportation in the library. As well authors recognize the map in the library in the open shelf type library, it grips the book, worked aided design and development of robots has the aim to perform the transportation and moved to a predetermined location. The cost of the plane in facilities of interest was also to take a policy of design and development of considering robot. And a versatile robot development that aims to build as applicable systems in many libraries.

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Gait planning method of multi-legged walking robot for transition to the target posture from the arbitrary posture is important in order to work in rough terrain. In this paper, we propose a gait planning method which can find a gait for transition to the target posture form any posture using bidirectional graph search method. We report the effectiveness of this method was confirmed by computer simulation.

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A lane tracking steering control system with a preview point was described. The system is the target yaw rate is calculated based on the lateral deviation at the preview point and the vehicle can follow the target course by being controlled to generate the yaw rate. In previous studies, the damping ratio of the tracking system was fixed to critical value. We proposed a new algorithm with two preview points and found that it is possible to achieve arbitrary dynamics of lane tracking performance with no steady state error. Moreover, it is possible to make preview point shorter than one of preview algorithm.

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A solar power sail demonstrator IKAROS, which was launched in 2010, could accelerate and decelerate by receiving solar radiation pressure to its membrane surface in outer space. However, the membrane surface becomes uneven easily, because the membrane is very thin. The unevenness causes swirling motion, changing the spin rate and deterioration of the power conversion efficiency. In this study, we proposed a shoelace structure to solve this problem. Effect of a shoelace structure for connecting divided sails on stress fields of sails was analyzed by using ABAQUS. Experimental design using orthogonal table revealed the conditions for reducing the compressive stress. In addition, optimal angle in consideration of the interaction has been derived.

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This paper describes the mechanical design of the small amphibious mobile robot for environmental monitoring. To realize the body having amphibious locomotion performance by simple mechanism and principle of operation and high stability on the water, we proposed the amphibious propulsion crawler, the waterproof driving mechanism using commercially available case and magnet coupling, body shape which realizes the Limit of Positive Stability (LPS) of about 180 deg. Especially the body shape was designed by computing the position of the center of gravity and the center of buoyancy with various height of the draft and aspect ratio. The prototype of a small amphibious mobile robot was designed based on these concepts.

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This paper describes development of a three somite earthworm type inspection and repair work robot which is able to move in small diameter pipes. Deterioration of the water pipes is a problem in recent years. It's ideal to replace that. However, it takes a large amount of expense and time to replace it. There is Pipelining as a measure of aging. Pipelining is a method of repairing the water pipes. But, there are several problems with this method. We manufactured of inspection and repair work robot as a method to improve a problem. We confirmed that can work in the pipes.

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This paper describes development of an in-pipe mobile robot driven by pneumatic pressures. Town gas is supplied to houses through polyethylene pipes laid under the road. It is necessary to inspect these pipes regularly caused by the gas leak owing to earth load and oscillation for driving cars on the road. So we manufactured in-pipe mobile robot driven by pneumatic pressures on the model of a green caterpillar. The robot is structured by three somite and four suction brakes. In this work, we researched best diameter of suction brake to move in-pipe, robot's moving speed and traction force. As a result, the diameter of suction was 18 mm, the speed was 9.7 mm/s and the force was 4.2 N.

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This paper reports on identifying the moving principle of the robot, it is possible to know when designing the tractive force that can lead the inspection equipment. The prototype robot is made up of the inspection unit and the moving part. Moving section using three pneumatic actuators, to mimic the behavior of the beneficial earthworm to the movement of the narrow place. Pneumatic actuators, since it is possible to issue a large force is light, the robot has the merit force greater for pulling and inspection equipment.

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This paper describes on the development of an operational assistance system in an overhead traveling crane. In the crane operation, the skill with obstacle collision avoidance, suppression of the load sway, and transferring to the target position in a short time is required. However, it is difficult to acquire the skill in the practical field. Therefore, the operational assistance system for avoiding the obstacles collision is proposed in this paper. The proposed system is realized by the system integration of the environment recognition and 3-DOF joystick with force display. The effectiveness of the proposed system is verified by the experiments with the laboratory-type overhead traveling crane.

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In recent years, various autonomous mobile robots are developed with the aim of being made perform tasks in environments, which humans exist such as service task and medical care. However, these studies didn't estimate the risk that is the robots collision to humans. In this study, a real-time path planning method for the autonomous mobile robot based on the risk distribution of the collision to a human is proposed. The avoidance trajectory is generated by the distribution of the severity of harm and probability of occurrence of harm. In this report, we will report on the results of the avoidance trajectory generation by simulation.

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This paper deals with a control method to follow the reference signals of the position and the contact force for the two-link manipulator. The virtual impedance control method improves the control performance by considering the virtual springs and the dampers in x-direction and y-direction. However, the manipulator is received the effect of the friction when the two-link manipulator pushes the wall and moves on the contact surface. This problem makes worse in the performance of the control system. In this study, the disturbance observer is installed in LQI control system, and the simulations are done. As a result, input torques is improved. And the two-link manipulator follows the reference signals of the position and the contact force.

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Propositions of this study is to develop control methods for a wearable power assist system (powered suit). In this study, as a first stage to develop the assist system, we do a load estimation for a 1-link arm, and the control of assist motion by using an acceleration sensor and a myoelectric sensor. The method of the load estimation is determined by the motion equation of 1-link arm by using the acceleration sensor. The assist motion is classified with 3 patterns, and each assist motion is recognized by the values of the myoelectric sensor. In this study, we propose the methods for carrying out these techniques in a series of operations, and verify each motion.

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An increasing number of small-sized vehicles like a personal mobility are being developed these years since environmental and energy-saving performance have gained considerable importance on mobility developments. The feature of these vehicles is smaller and lighter than traditional vehicles. It is expected that motion of human body has a large influence on running performance of the vehicle, and this affects vehicle stability and human safety. This report examines interactions between a vehicle and a human from simulation results by a simulation model that consists of a vehicle model like a personal mobility and a human model that expresses human motion. It is demonstrated that interactions between the vehicle model and the human model depend on vehicle spec and mass ratio.

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The most serious head injury in judo is acute subdural hematoma (ASDH). ASDH occurs because of bridge vein's failure by rotation of brain in skull. Although ASDH is related to intracranial behavior, the relationship between intracranial behavior and motion of body is unclear. In this study, multibody dynamics model is developed to describe the intracranial behavior on occiput impact. This model is composed of 5 rigid bodies (brain, head, neck, torso and floor) and 2 joints at 1st and 7th cervical vertebrae. The intracranial model has the elastic and viscous elements of bridging veins, brain stem and arachnoid trabeculae and the contact springs and dampers of skull base, tentorium cerebella and skull. Moreover, the effects of cerebral spinal fluid are considered. Developed model was compared with the experimental results with cadaver and dummy, and the results showed the validity of the developed model.

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In recent years, some systems which contain a floating body, such as Unmanned Aerial Vehicle (UAV) connected with a tether, are used for transportation. However, the coupling motion of the system is not easily predicted with high accuracy and may induce instability of the floating body. Therefore, to control the system, comprehension of the motion of the whole system is of great importance to control the system. In this investigation, modeling and formulation of the tethered system which contains a floating body is presented using Absolute Nodal Coordinate Formulation (ANCF) and the result of the numerical simulation of the motion is discussed.

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This paper deals with numerical simulations of the mooring chain subjected to hydrodynamic forces due to wave motion. We developed an analytical model the mooring chain by using the finite segment method. From this analytical model, differential algebraic equations of the mooring chain are derived as a finite segment formulation. The dynamic behavior of the mooring chain is examined and discussed by the numerical simulation. The mooring chain shows various deformations by gravity and hydrodynamic forces, and it generated nonlinear characteristic. As a result, it is found that the dynamic behavior or the mooring chain by hydrodynamic forces influenced the magnitude of curvature. More, the dynamic behavior of the mooring chain is discussed by numerical simulations.

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In various fields of engineering, it is important to clarify friction-induced vibration, such as stick-slip motion, for a wide range of scales from microscopic elements to continental plates. In particular, it has been known that stick-slip tends to appear at high contact loads and low driving speeds. However, the mechanism of stick-skip remains to be elucidated. In addition, significant problem of the conventional Discrete Element Method (DEM) model can not describe a transition from slip to stick state. In the case of conventional friction model in DEM, the body will be sliding even though friction state is stick. In this study, the stick-slip friction model is proposed and implemented into the conventional DEM model. Furthermore, in order to verify the validity of stick-slip friction model, the behaviors of stick-slip motions were examined through experiments and simulations performed by modified DEM.

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