• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1188-1194
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• 2008

Derail accident of train and motorcar through signal override causes such a huge obstruction in train service. To minimize such derail accidents, number of bills were examined such as installing normal and reverse position indicator on the switch. A indicator was necessary which does not affect current equipments and not to be confused as traffic lights. Normal and reverse position indicator is installed in the middle of the rail in front of front rod of switch. It is to prevent derail accident while manual handling of obstacle by ease of verifying normal and reverse position by attendants or motorcar driver. Also, it is a device that prevents accidents by indicating normal and reverse position of switch during night service of motorcar. Such a prevention accomplished through thorough maintenancework of equipment, precise handling of operators and exterior factors are eliminated or perceived and treated well.

• Proceedings of the ESK Conference
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• 1997.04a
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• pp.95-99
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• 1997

Most studies in manual material handling (MMH) have paid more attention to single MMH activities-lifting, lowering, carrying, holding, pushing or pulling and have ignored combined activities. Also, many studies have been involved with two-handed MMH activities rather than to one-handed MMH activities. Very few studies are reported on the determination of workers' capacities for combinations of one-handed MMH activities (e.g. lifting a box, then carrying the box, and lowering the box). The objective of this study was to utilize the psychophysical approach to examine the combinations of lifting, carrying and lowering activities from a simulated industrial task involving one- handed and two-handed combined tasks and to develop mathematical models for combined tasks. Ten male students served as subjects for the study. The capacities that were determined as the maximum acceptable weight workloads for 1 hr work period for one-handed and two-handed combined tasks-lifting a box from floor to knuckle height, carrying the box for 4.3 m, and lowering the box form knuckle to floor height -were determined psychophysically under three frequencies: six handlings per minute, one handling per minute and one handling per five minutes. Combined MMH capacities models for one-handed tasks were developed. Te advantages and disadvantages of different models are discussed.

• Journal of the Ergonomics Society of Korea
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• v.28 no.3
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• pp.17-25
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• 2009

This study was aimed to analyze of characteristics of Musculoskeletal disorders (MSDs) based on the industrial accident statistics which were extracted from the Ministry of Labor. In this study all MSDs cases in 2007, 7,723 cases, were investigated. First of all, for the analysis of a wide view point concerning the characteristics of MSDs, We have inspected characteristics of the user population (i.e. age, gender, employed periods, etc.). Secondly, work-related risk factors such as repetitive motions, awkward postures, manual material handling were analyzed in terms of disease code, injured part of body, types of business, etc. Next, characteristics of handling of heavy materials were analyzed according to weight, types of handling, agency of cause, etc. Finally, we have compared and analyzed the features between the period of hospitalization and other variables. In addition to that we also conducted statistics analysis. The study results showed that there were significant characteristics of MSDs that could be used as basis data for the MSDs prevention policy.

• IE interfaces
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• v.20 no.1
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• pp.21-32
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• 2007

This paper deals with the simulation model for A-Mart logistic center design and operations. In developed simulation model, receiving docks, conveyor sorter, conveyor system, shipping docks, material handling devices and manual sorting stations are considered. Three types of cargo such as transfer center cargo, distribution center cargo and supermarket cargo are considered. The simulation model and process animation are developed using the simulation package ARENA. Among various design and operation alternatives consisting of the number of workers of receiving dock, allocation of receiving docks by cargo types, conveyor sorter velocity, the number of folk-lift, the number of manual sorting operators and overall layout, the best alternatives of each subsystem are selected by simulation analysis. The major performance measures such as sorter throughput, utilization of operators at each station, receiving docks utilization and folk-lift utilization are considered for the alternative evaluation.

• Journal of Korean Institute of Industrial Engineers
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• v.42 no.3
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• pp.165-172
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• 2016

The purpose of this study is to investigate the ergonomic verification of suitability of the 4-wheeled hand cart to prevent musculoskeletal problems in the firing test range. Because of the increasing amount of firing test, the needs to develop a projectile transferring device such as 4-wheeled hand cart has been increased. For the 4-wheeled hand cart, the lifting and carrying activity in the manual handling method were transformed to pushing activity. The risk of low back pain for lifting and carrying the projectile by manual was estimated by NLE and 3D SSPP. On the other hand, the risk for pushing the 4-wheeled hand cart was estimated by psychophysical and biomechanical method such as Mital's equation, Snook's table and 3D SSPP. It was shown that the 4-wheeled hand cart reduced the risk of low back pain drastically with higher efficiency and design compatibility.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.281-291
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• 1999

Productivity of container cranes and gantry cranes is influenced by the performance of crane hardware and cycle time. Cycle time in container handling is influenced by the path of containers and relative positioning of containers. So we have to minimize the sway of containers and spreaders to minimize relative positioning time. And sway minimization is influenced by the skill of workers in manual gantry cranes. In this paper, we will develop anti-sway system using mechanical and electrical method. Proposed hybrid system uses the basic structure of general manual gantry crane. So, it is very useful and effective. Electrical methods are main methods and mechanical methods are auxiliary methods.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.56
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• pp.93-102
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• 2000

Today, the number of automated machine has rapidly increased in industrial workplaces. Nevertheless, workers are often required to handle materials manually. Technical information for using the revised NIOSH lifting equation to evaluate a variety of two - handed Manual Material Handling (MMH) tasks was investigated. The NIOSH suggested the Lifting Index that provides a relative estimate of the level of physical stress associated with a particular manual lifting task. To measure operator's workload in lifting task, Lifting Index Simulator(LIS) was developed based upon the revised NIOSH lifting equation in this study. The purpose of this study was to develop LIS and use the NIOSH lifting equation in our workplace.

• Journal of the Korea Safety Management & Science
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• v.2 no.2
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• pp.11-20
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• 2000

Today, technologies and automation have been accelerated up in the industrial workplace. Nevertheless, many systems still require humans to handle materials manually. The Low Back Pain (LBP) is one of modern human being's most common and complex ailments. Many risk factors with the onset of LBP have been identified, however, lifting out of Manual Material Handling(MMH) was the most important factor to the LBP. The Virtual Reality(VR) is used in a variety of ways and often in a confusion and misleading manner. In order to solve the prevention of the LBP, a lifting box was translated in the Virtual Environment(VE). As simulating under the VE, optimal lifting works could be constructed. The purpose of this study is to reduce the chronical low back pain for the manual material handlers.

• Journal of Power System Engineering
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• v.19 no.2
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• pp.15-21
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• 2015

Bollard installed on the street is a facility that protects pedestrians by restraining cars from entering on the sidewalk. It is basically classified into manual, semiautomatic, automatic type and mostly manual type is widely used because the automatic type is imported and much expensive. However, in case of manual handling type in practice, it is very troublesome and difficult to remove it whenever cars are permitted, and in case of automatic type, since underbody of a bollard is very long, it is difficult to dig a deep hole in the ground because a pipe, a hose or a cable is under the surface. In order to reduce these difficulties, this paper proposed new design of the multistage bollard that moves up and down automatically by using hydraulic system. This is developed by 6 step creativity of TRIZ inventive problem solving and structural analysis. The developed bollard can be installed in shallow hole and allow entry of vehicles through up-and-down movement without its removal manually. Finally, we could see smoothly motion through the manufactured bollard.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.2
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• pp.240-248
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• 2009

Modem version of supersonic jet fighter aircraft must have been guaranteed appropriate controllability and stability in HAoA(High Angle of Attack). The HAoA flight control law have two parts, one is control law of departure prevention and the other is control law of departure recovery support. The control laws of departure prevention for advanced jet trainer consist of HAoA limiter, roll command limiter and rudder fader. The control laws of departure recovery support are consist of yaw-rate limiter and MPO(Manual Pitch Override) mode. The guideline of pitch rocking using MPO mode is simple, but operating skill of pitch rocking is very difficult by the pilot with inexperience of departure situation. Therefore, automatic deep stall recovery system is necessary. The system called the "Automatic Pitch Rocker System" or APRS, provided a pilot initiated automatic maneuver capable of an aircraft recoveries in situations of deep stall, speed and altitude. This paper addresses the design and validation for APRS to recovery of an deep stall without manual pitch rocking by the pilot. Also, this system is designed to recovery of speed, attitude and altitude after deep stall recovery using ATCS (Automatic Thrust Control System) and autopilot. Finally, this system is verified by real-time pilot evaluation using HQS (Handling Quality Simulator).