• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2013.11a
• /
• pp.192-193
• /
• 2013

The purpose of this research is to comprehend experimentally the nature of human static load to wall for making use of the result as basic data to evaluate resisting force of lightweight wall. Human motions exerting static load are classified to 4 types, and two-hands pushing and shoulder pushing are defined as the instantaneously forcing motions with hands or shoulder put on the load plate, respectively. Back leaning and one-hand leaning are defined as motions of taking a rest in their respective comfortable posture. Measurement of static horizontal load caused by each motion showed that the highest load ratio depends on hardness of load plane and was 1.17~1.25 times of weight in two-hands pushing, 0.95~0.99 times in shoulder pushing, 0.16~0.18 times in back leaning, and 0.12~0.15 times in one-hand leaning.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2016.05a
• /
• pp.93-94
• /
• 2016

The resistance of crowd pressure is an important performance to be influential on safety of facility users among performances required for light weight walls of public facilities. This study has empirically evaluated the estimation of size of crowd pressure to be applied to a wall of structure. For the load analysis test, the force plate with stiffness of 28 kN/cm was designed and manufactured. For inspectors, 15 males in the age of 20s were selected. The action of putting load was set as instantaneous push of plate and continuous push. As the load was increased linearly from the weight of inspector, the size of load was indicated as the load ratio. In case of instantaneous force, about 1.18 times the weight of pushing personnel was acted as a load. In case of continuous push, about 0.80 times the weight of pushing personnel was acted as a load.

• Proceedings of the KIEE Conference
• /
• 2000.07c
• /
• pp.1690-1692
• /
• 2000

The principle of crimping connection is to produce a compressive connection force between terminal and cores(wire conductor). Compressive connection force is produced by pushing each other on that stress(crimping force) of barrel by restored elastic strain after plastic deformation and the expansion force of cores' elastic stress. And resistance and tension force between terminal and cores are determined according to the condition of compressive connection force. In this study, we've found out that the adaptive height which has maximum tensile force by measuring a tensile force with a height of terminal.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.9
• /
• pp.5820-5825
• /
• 2014

The aim of this study was to verify the suitability or unsuitability of Korean body types by measuring the opening force criteria of an air pressurized access door to a smoke control zone. The opening force criteria were verified by comparing the NFSC 501A, NFPA 92A and BS-EN 12101-6 based on the body standards information from the Korean Agency for Technology and Standards. When measuring the opening forces, the posture of the body should be standing upright and pushing an access door with the right hand, which is a criterion for designing doors. As a result of analyzing the actual measurement results, the pushing force of men and women in their 30's was the maximum value and the forces in those in their 60's was the minimum value. In addition, the deviations in the pushing forces varied considerably. As a result of comparing the NFSC 501A, the men showed lower values than the criteria in every gender and age variable except for the 20's, 30's and 50's variable. A comparison of the criteria of NFPA 92A showed that the mean of the measured values from every gender and age was also lower than the criteria. In addition, when comparing the criteria of BS-EN 12101-6, it was found that the men in every age variable were higher than the criteria. On the other hand, the women in every age variable were lower than the criteria. Therefore, considering the Korean body type against the Western body type, it was decided that the opening force of an access door to a smoke control area to make a downward adjustment should be 110 N in the local criteria. Furthermore, the criteria should consider the characteristics of buildings and users because an optional application of the international standard is not necessarily suitable for local situations.

• Journal of the Korean Society of Safety
• /
• v.26 no.1
• /
• pp.58-64
• /
• 2011

This study evaluated the effects of the handle width(shoulder width, 1.25${\times}$shoulder width, 1.5${\times}$shoulder width), height(3 levels : knee, medium, knuckle) and horizontal angle($0^{\circ}$, $10^{\circ}$) on the pushing, lifting, and twisting strengths which were required for carrying single or two wheel barrows. Twelve healthy college students(male) participated in the experiment. In each experimental condition($3{\times}3{\times}2$=18), the subjects exerted three forces(pushing, lifting, and twisting clockwise). The experimental conditions and three forces were tested in random order, and a minimum 2 minutes of rest was provided between exertions. Results showed that the mean and maximum pushing forces showed greater values when the horizontal angle was $0^{\circ}$ than $10^{\circ}$(p=0.016). However, the three independent variables had no statistically significant effects on the lifting forces(p>0.1). The mean and maximum twisting forces increased as the handle width became larger(p<0.05). Also, there was a marginal effect of the horizontal angle(p=0.065) on the twisting force. From the results of this study, the horizontal angle of $0^{\circ}$ and the wider handle width were suggested for the design of single-wheel barrows.

• Journal of Biosystems Engineering
• /
• v.34 no.4
• /
• pp.286-294
• /
• 2009

A high prevalence of protected horticulture farmer's work-related musculo-skeletal disorders (MSDs) have been reported in precedent studies. One of the tasks required ergonomic intervention to reduce the musculo-skeletal risks is the task of product transporting. The purpose of this study is to evaluate quantitatively the spinal load of operator using manual vehicles to predict and prevent musculo-skeletal risks. Spinal load in operators using 4 kinds of manual vehicle were analyzed. Before evaluating spinal load on operator using the manual vehicles by bio-mechanical approach, it is needed to validate human model. In this study, ADAMS LifeMOD human model shows satisfactory results, comparing with already validated model's results or measured results. While Operators pushed the manual vehicles(wheelbarrow, Trolley, 2 wheel cart, and 4 wheel cart) contained loads that were 0 N and 800 N, their spinal loads(compression force, shear force) were evaluated. The compression force demonstrated under the NIOSH action limits - 3410N - for all 4 manual vehicle's operators(McGill 1997; Marras 2000). However, the lateral shear force demonstrated over the University of Waterloo - 500N - for all 3 manual vehicle's operators except 4Wheel cart (Yingline and McGill, 1999). Therefore, operators have risks in prevalence of the musculo-skeletal disorders due to shear force. The findings of this study suggest that it need to be determine the spinal load, especially lateral shear force in designing the manual vehicles in the future.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.11a
• /
• pp.249-255
• /
• 2000

The design and test of an magnetostrictive linear motor(MLM) that operates based on self-moving cell concept is presented. The moving cell is composed of Terfenol-D linear actuator and a ring structure, and a cell train is constructed by connecting two cells in series. Since this motor uses the stroke of Terfenol-D actuators and friction force of the cells, it can essentially produce long stroke and large force. The overall performance of the MLM was measured in terms of speed and force. The pushing force is directly related with the friction force. This work is a proof-of-concept stage and investigation is necessary for realistic application.

• 제어로봇시스템학회:학술대회논문집
• /
• 1989.10a
• /
• pp.1080-1084
• /
• 1989

The motion of an workpiece to be manipulated is determined by the forces applied to the workpiece. During the contact between the robot hand and the workpiece, impulsive forces may dominate all other forces, and determine the ultimate success or failure of a task. Therefore, one of the important problems in the robot hands is the control of the initial impact force. In this paper, the problem of the force control of robot hand under system with contact force is presented. The principle of energy can be applied in the modelling of the impact force. In order to achieve stable contact and avoid bounces and vibrations, VSS is adopted in the design of the contact force controller. Some simulations are carried out for a pushing operation to control the contact force.

• Transactions on Control, Automation and Systems Engineering
• /
• v.3 no.4
• /
• pp.236-241
• /
• 2001

Teach pendant is the most widely used means of robot teaching at present. Despite the difficulties of using the motion command buttons on the teach pendant, it is an economical, robust, and effective device for robot teaching task. This paper presents the development of a force/moment direction sensor named COSMO that can improve the teach pendant based robot teaching. Robot teaching experiment of a six axis commercial robot using the sensor is described where operator holds the sensor with a hand, and move the robot by pushing, pulling, and twisting the sensor in the direction of the desired motion. No prior knowledge of the coordinate system is required. The function of the COSMO sensor is to detect the presence f force and moment along the principal axes of the sensor coordinate system. The transducer used in the sensor is micro-switch, and this intuitive robot teaching can be implemented at a very low cost.

• Journal of Drive and Control
• /
• v.12 no.4
• /
• pp.35-40
• /
• 2015

A gas spring provides support force for lifting, positioning, lowering, and counterbalancing weights. It offers a wide range of reaction force with a flat force characteristic, simple mounting, compact size, speed controlled damping, and cushioned end motion. The most common usage is as a support on a horizontally hinged automotive tail gate. However, its versatility and ease of use has been applied in many other industrial applications ranging from office equipment to off-road vehicles. The cylinder of a gas spring is filled with compressed nitrogen gas, which is applied with equal pressure on both sides of the piston. The surface area of the rod side of the piston is smaller than the opposite side, producing a pushing force. The magnitude of the reaction force is determined by the cross-sectional area of the piston rod and the internal pressure inside the cylinder. The reaction force is influenced by many design parameters such as initial chamber volume, diameter ratio, etc. In this paper, we investigated the reaction force characteristics and carried out parameter sensitivity analysis for the design parameters of a gas spring.