• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.144-144
• /
• 2000

Air balance hoists are widely used in handling of heavy materials in industry. Currently used air balance hoists adopt manual switches for vertical motion, thus the operator has a difficulty in operating of the switches and handling of material simultaneously. To overcome this difficulty, this study develops a weightless air-balance-hoist system using compressed air. This system memorizes the weight of material in terms of pneumatic pressure with a pneumatic circuit. Such memory of the material weight is used for achieving weightless handling of materials. Through a series of experiments, handling forces and the response of the system for various material weights are analyzed. The results show that the developed system can be used for weightless handling o( heavy materials.

• KSTLE International Journal
• /
• v.4 no.1
• /
• pp.27-30
• /
• 2003

The basic principles of tribo-systems and study method based on tribe-systems are introduced in the paper, Based on the viewpoint of tribe-systems, the experiment on tribology characteristics of friction lining material in multi-rope friction hoist is carried out. The research result shows: tribology characteristics of friction material are not its inherent characteristic but system characteristics of the tribo-systems, the“sliding-rope”of multi-rope friction hoist can be divided into“safety sliding-rope”and“fault sliding-rope”, study on friction material only based on characteristic of system where friction material exists possesses practical significance.

• Journal of the Korean Society of Tobacco Science
• /
• v.23 no.1
• /
• pp.90-93
• /
• 2001

In order to save hanging labor hours and reduce work intensity for bulk curing of the flue-cured tobacco, and electric hoist was developed. It consists of a pair of square steel frames with side plates and rolling casters to move back and forth on the second tire of bulk barn, and wire rope type lift was attached to the beneath of its top center. The lift driven by DC motor could be controlled by operating switch with one limit switch and control box, and a scissors shaped gripper was deviced to grip tobacco rack to the end of wire rope. As the results of experiments with electric hoist, labor hours for hanging could be saved by 30 to 40% as compared with those in conventional method. With simple and light structure, it was possible for even woman to load the harvested tobacco, and it could be recommended for farmers to use this device with reasonable price.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.38 no.10
• /
• pp.1109-1116
• /
• 2014

The wheelchair mechanism for a car that is proposed in this study primarily consists of a transfer mechanism and storage mechanism. The wheelchair transfer mechanism consists of a manipulator installed in the roof of a car, and performs the function of transferring the wheelchair from the driver's seat to the trunk. The wheelchair storage mechanism consists of a lifting hoist installed in the trunk of car, and performs the function of storing the transferred wheelchair in the trunk and safely fastening it in place. This study analyzed and reviewed various manipulators, including a vertical type, Scara type, and telescopic type, with the goal of selecting the best type of manipulator for the wheelchair transfer mechanism. The telescopic type was selected and applied because of its good load support and storage capabilities. In addition, with regard to the wheelchair storage mechanism, a slide hoist type that used a slide rail and lift wire and a rotating link hoist type that used a rotating mechanism consisting of a worm gear and link were analyzed and reviewed. The slide hoist type was selected and applied because it had an advantage in relation to trunk space utilization. This study proposed a wheelchair transfer mechanism for a car to support a conventional wheelchair user's movements, and in order to conform to the structure of a domestic welfare car for the disabled.

• Proceedings of KOSOMES biannual meeting
• /
• 2018.06a
• /
• pp.178-178
• /
• 2018

• Journal of the Korean Operations Research and Management Science Society
• /
• v.18 no.2
• /
• pp.131-145
• /
• 1993

This paper deals with scheduling problem of the chemical process system where aircraft parts go through a given sequence of tanks filled with chemical solutions. The system has two hoists which move carriers holding the parts between tanks. A mixed integer programming model is developed from which a maximum throughput schedule can be found for the hoist movements. To show the validity of the model, a real world problem is solved and the results are compared with those with an existing approach.

• Journal of Korea Fishing Vessel Association
• /
• v.29
• /
• pp.64-68
• /
• 1986

• Structural Engineering and Mechanics
• /
• v.66 no.5
• /
• pp.583-594
• /
• 2018

A theoretical formulation based on the linearized potential theory, the Descartes' rule and the extremum optimization method is presented to calculate the critical distance of lifting points of the fully balanced hoist vertical ship lift, and to study pitching stability of the ship lift. The overturning torque of the ship chamber is proposed based on the Housner theory. A seven-free-degree dynamic model of the ship lift based on the Lagrange equation of the second kind is then established, including the ship chamber, the wire rope, the gravity counterweights and the liquid in the ship chamber. Subsequently, an eigenvalue equation is obtained with the coefficient matrix of the dynamic equations, and a key coefficient is analyzed by innovative use of the minimum optimization method for a stability criterion. Also, an extensive influence of the structural parameters contains the gravity counterweight wire rope stiffness, synchronous shaft stiffness, lifting height and hoists radius on the critical distance of lifting points is numerically analyzed. With the Runge-Kutta method, the four primary dynamical responses of the ship lift are investigated to demonstrate the accuracy/reliability of the result from the theoretical formulation. It is revealed that the critical distance of lifting points decreases with increasing the synchronous shaft stiffness, while increases with rising the other three structural parameters. Moreover, the theoretical formulation is more applicable than the previous criterions to design the layout of the fully balanced hoist vertical ship lift for the ensuring of the stability.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.10 no.8
• /
• pp.867-874
• /
• 2015

Hoist have been installed at wharfs or seashore in the center of fishing village fraternities. A Hoist is used in harbor loading and unloading fishing gear or seafoods and is a device to refloat fishing boats into a breakwater or land in case of typhoon or bad weather. In this paper, we propose image perception and moving objects tracking system that detects boat's damage, theft and trespassing occurred at the wharf. This system detects objects' motion in real time by using the motion templet and tracks to concentrate on a moving object(person, boat, etc.) by using a PTZ camera.

• Journal of Korean Institute of Industrial Engineers
• /
• v.42 no.3
• /
• pp.173-181
• /
• 2016

This paper deals with the single-hoist and multiple-products scheduling problem. Although a mixed integer linear programming model for the problem was developed earlier, a branch-and-bound based heuristic algorithm is proposed in this paper to solve the big-size problems in real situation. The algorithm is capable of handling problems incorporating different product types, jobs in the process, and tank capacities. Using a small example problem the procedure of the heuristic algorithm is explained. To assess the performance of the heuristic we generate a bigger example problem and compare the results of the algorithm proposed in this paper with the optimal solutions derived from the mathematical model of earlier research. The comparison shows that the heuristic has very good performance and the computation time is sufficiently short to use the algorithm in real situation.