Seat Arrangement Research Articles

Intermuscular coordination during pendulum rebound exercises

In this study, we assessed coordination during pendulum rebound jumps. To gain insight into the movement coordination strategy, nine experienced male volleyball players performed maximal rebound jumps in a pendulum swing device using three different seat arrangements (90±x00B0;, 135±x00B0; and 180±x00B0;). Two-dimensional filming was performed in the right sagittal plane (200Hz) synchronized with a force platform fitted to the wall (1000Hz). The surface electromyograms of five muscles were recorded (200Hz), in conjunction with kinematic and kinetic assessment. During the countermovement phase, the impact forces were attenuated by eccentric contractions of most muscles, which helped to reduce the energy input into the system. The wall reaction forces, net moments and joint power profiles were comparable between conditions. The small differences found between the extreme seat arrangements were attributed to differences in muscle length and the position of the feet. The strategy used during landing was similar to that observed in unconstrained vertical and drop jumps, where the neuromuscular system attenuates the impact forces. During the push-offphase, most muscles were found to contribute to positive work generation, except the semitendinosus, which was stretching throughout the propulsive phase. Despite not being able to exert a large influence over the trunk segment, this muscle was deemed to play an important role in regulating and synchronizing the onset of knee extension, enabling hip extension to occur before extension in the other more distal joints. Our findings show that the neuromuscular system is able to produce consistent movement coordination across experimental conditions and in accordance with the specific task demands and constraints imposed in the movement structure.

Coach design for the Korean high-speed train: a systematic approach to passenger seat design and layout

Proper ergonomic design of a passenger seat and coach layout for a high-speed train is an essential component that is directly related to passenger comfort. In this research, a systematic approach to the design of passenger seats was described and the coach layout which reflected the tradeoff between transportation capacity and passenger comfort was investigated for the Korean high-speed train. As a result, design recommendations and specifications of the passenger seat and its layout were suggested. The whole design process is composed of four stages. A survey and analysis of design requirement was first conducted, which formed the base for designing the first and second class passenger seats. Prototypes were made and evaluated iteratively, and seat arrangement and coach layout were finally obtained. The systematic approach and recommendations suggested in this study are expected to be applicable to the seat design for public transportations and to help modify and redesign existing vehicular seats.

A Quantitative Evaluation Method of Seat Arrangement for Commuter Railway Vehicles from the Viewpoint of Comfort and Accessibility.

In this paper, we propose a quantitative evaluation method for seat and door arrangements in commuter railway cars from the viewpoint of passenger comfort and accessibility. Passenger comfort is defined based on passenger's behavior in selecting a seat, with the assumption that every passenger selects the most comfortable seat from those available. The behavior is modeled by a numerical function. The unknown parameters in the evaluation function are determined by experiments using a full-scale mockup with variable seat and door arrangements. The results of the proposed evaluation functions using computer simulations agreed with experimental results. It was found that the seat arrangement depends on the average passenger traveling time. From the evaluated results, the best seat arrangement for commuter trains is discussed and new seat arrangements are proposed.

A Quantitative Evaluation Method of Seat Arrangement for Commuter Railway Vehicles from the Viewpoint of Comfort and Accessibility.

This paper presents a quantitative evaluation method for seat arrangements in commuter railway cars. The purpose of the study is to evaluate seat arrangements based on passenger comfort and accessibility, which are important during train operation. To determine the unknown parameters in the function, experimental examination was done. A full-scale mockup with variable seat arrangements was manufactured. It was modeled on a 20 m-long car with four or six doors per side, because a choice of the door arrangement is one of the main parameters. Using this mockup, comfort and accessibility were measured for ten types of seat arrangements. The results of the proposed evaluation functions using computer simulations agreed with measured experimental results. Applying the evaluation method to several seat arrangements, it is found that the most suitable seat arrangement depends on the average boarding time of passengers. From the evaluated results, suitable seat arrangements for commuter trains are discussed.

The Experimental Study of the Effects of Seat Arrangement on One's Feelings

The Experimental Study of the Effects of Seat Arrangement on One's Feelings

Multi‐directional vibration attenuator seat

MULTI-DIRECTIONAL VIBRATION ATTENUATOR SEAT Abstract of the Disclosure A multi-directional vibration attenuator seat is capable of limited, restrained movement in any direction within a generally horizontal plane in response to vibration and other motions of the seat and the vehicle in which the seat is mounted. The limited movement is made possible by a seat arrangement in which an intermediate assembly is disposed on top of and slidable relative to a base assembly along a first axis with a seat supporting upper assembly being disposed on and slidable relative to the intermediate assembly along a second axis extending in a direction generally perpendicular to the direction of the first axis. The seat is normally maintained in and is restrained from movement out of a nominal position relative to the base assembly by a plurality of springs. A pair of shock absorbers disposed generally perpendicular to each other damp movement of the seat along the first and second axes respectively. An adjuster latch and lever arrangement is used to position the base assembly at a selected location along a pair of slidable adjusters on which the base assembly is mounted. Attenuating movement of the seat can be locked out by a manually controlled lever which drops a pin through an aperture in the base assembly from the upper assembly to lock the various assemblies together. The seat is preferably mounted for rotation about the upper assembly, which rotation can be locked out by a swivel lock lever and toothed plate arrangement.

A cryogenic pressure regulator

A pressure regulator especially suited for cryogenic fluid and two-phase (gas and liquid mixture) flow application such as an aircraft fuel tank inerting system wherein the regulator controls the pressure and rate of flow of inerting fluid, e.g. nitrogen, into the fuel tank to pressurize the tank and to inert the tank ullage gases to render them noncombustible, said regulator being characterized in that the flow control valve has large and small variable area orifices which operate in sequence to minimize overshoot and undershoot, in that resonant oscillation is predictably damped and the damping remains substantially constant despite wear or change in clearances of the parts, and in that the valve actuator is thermally isolated from the cryogenic fluid flow path. The use of the tandem or sequential valve seat arrangement aforesaid also allows the larger seat to have an extended life and greater resistance to contamination and wear because at low flow demands, the larger valve portion remains seated and thus does not operate extremely close to its seat while the smaller valve portion partakes of greater stroking relative to its seat to satisfy such low flow demands. Furthermore, the regulator herein has a configuration such as to produce a large mechanical advantage to enable the regulator to provide a narrow pressure control band even with large variations in inlet fluid pressures and flow demands, this large mechanical advantage being obtained by the use of the rotary motion of a crank shaft having long and short crank arms.