• Journal of the Korean Institute of Rural Architecture
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• v.16 no.1
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• pp.95-102
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• 2014

The number of industrial accident victims in the construction industry accounts for 1/3 of those in the entire industries and about 30% of the total compensation costs are spent in the construction industry. As such, the construction industry is a typical industry causing numerous safety accidents. This study analyzes the status of industrial accidents in small scale construction sites to build maximum five-story buildings by examining statistical data for the past five years, investigating those construction sites and conducting interviews with the workers. This study also seeks the causes of and measures for industrial accidents in the small scale construction industry through comparison with relevant systems. The findings are as follows: (1) To reduce hazard rate, shaping the working environment and safety measures that take into account the physically weak classes of the middle aged and the aging are urgently required, because 62.9% of the industrial accidents in the construction industry occurred to those who are 50 years of age or older. (2) The hazard rate at small scale construction sites with less than 10 construction workers accounts for 55% of that of the entire industries. The government, in this context, needs to support finance or technology and improve system by selecting the small scale construction sites, where industrial accidents occur frequently. (3) Because the hazard rate of unskilled workers with less than 6 months of work experience accounts for 90.95% of the total, safety education needs to be concentrated on those unskilled workers. (4) The relevant standards need to be segmented and revised and bolstered, given that 64.79% of death disaster in the construction industry occurs in the temporary structures including scaffolds and ladders.

• Journal of Power Electronics
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• v.18 no.2
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• pp.467-481
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• 2018

Modular multilevel converter (MMC)-based high-voltage direct current (HVDC) presents attractive technical advantages and contributes to enhanced system operation and reduced oscillation damping in dynamic MMC-HVDC systems. We propose an advanced small-signal multi-terminal MMC-HVDC based on dynamic phasors and state space for power system stability analysis to enhance computational accuracy and reduce simulation time. In accordance with active and passive network control strategies for multi-terminal MMC-HVDC, the matchable small-signal stability models containing high harmonics and dynamics of internal variables are conducted, and a related theoretical derivation is carried out. The proposed advanced small-signal model is then compared with electromagnetic-transient and traditional small-signal state-space models by adopting a typical multi-terminal MMC-HVDC network with offshore wind generation. Simulation indicates that the advanced small-signal model can successfully follow the electromechanical transient response with small errors and can predict the damped oscillations. The validity and applicability of the proposed model are effectively confirmed.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.62 no.4
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• pp.210-215
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• 2013

This paper analyze the bus voltage sags in the power distribution system with a small scale cogeneration system when the superconducting fault current limiter was introduced. Among the solutions to decrease the short-circuit current considering the locations of the small scale cogeneration system, the superconducting fault current limiter (SFCL) has been announced as one of the promising methods to reduce the fault current because the installation of the small scale cogeneration system which increases the short-circuit current. According to the application locations of the small scale cogeneration system in a power distribution system, it has caused the variations of voltage sag and duration which depends on the change of the short-circuit current, which can make the operation of the protective device deviate from its original set value when the fault occurs. To investigate the voltage sag when a SFCL was applied into a power distribution system where the small scale cogeneration system was introduced into various locations, the SFCL, small scale cogeneration system, and power system are modeled using PSCAD/EMTDC. In this paper, the effects on voltage sags are assessed when the SFCL is installed in power distribution system with various locations of the small scale cogeneration system.

• Journal of Medicine and Life Science
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• v.16 no.1
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• pp.13-16
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• 2019

In a patient with blunt abdominal trauma with small bowel injury, early diagnosis is clinically challenging due to unclear clinical symptoms and signs in the early stage of an injury. On the other hand, a delay of diagnosis of bowel disruption may lead to increased complication and mortality. The diagnostic laparoscopy is very useful for the evaluation of the small bowel injury. Laparoscopy can reduce unnecessary open surgery in a patient with blunt abdominal trauma with subtle symptoms and imprecise findings on abdominal computed tomography. Also it can prevent delay of treatment and be converted immediately to open surgery as soon as bowel damage is revealed. Furthermore, extracorporeal repair of small bowel via mini-laparotomy after a single incision diagnostic laparoscopy in a patient with traumatic small bowel perforation was a feasible and safe alternative to conventional laparoscopy. We are pleased to introduce successfully treated cases by extracorporeal repair of small bowel via mini-laparotomy after a single incision diagnostic laparoscopy in a patient with small bowel perforation after blunt trauma.

• The Journal of Korea Robotics Society
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• v.18 no.3
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• pp.285-292
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• 2023

Small-scale ground mobile robots can access confined spaces where people or larger robots are unable. As the scale of the robot decreases, the relative size of the environment increases; therefore, maintaining the mobility of the small-scale robot is required. However, small-scale robots have limitations in using a large number of high-performance actuators, powerful computational devices, and a power source. Insects can effectively navigate various terrains in nature with their legged motion. Discrete contact with the ground and the foot enables creatures to traverse irregular surfaces. Inspired by the leg motion of the insect, researchers have developed small-scale robots and they implemented swing and lifting motions of the leg by designing leg linkages that can be adapted to small-scale robots. In this paper, we propose a leg linkage design for insect-inspired small-scale ground mobile robots. To use minimal actuation and reduce the control complexity, we designed a 1-DOF 3-dimensional leg linkage that can generate a proper leg trajectory using one continuous rotational input. We analyzed the kinematics of the proposed leg linkage to investigate the effect of link parameters on the foot trajectory.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.9
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• pp.174-181
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• 2004

Recently, many studies have been undergoing to reduce working time in field of machine tool. There are two ways of reducing working time to reduce actual working time by heighten spindle speed and to reduce stand-by time by shortening tool exchange time. Auto tool changer belongs to latter case. Fixed address type auto tool changer can store more number of tools in small space than magazine transfer Ope and can shorten tool exchange time. This study focuses on the topology optimization to reduce the weight of the fixed address type ATC. The optimization program using a real number coding genetic algorithm is developed and is applied to the 10-bar truss optimization problem to verify the developed program. And, it is shown that the developed program gives better results than other methods. Finally, The developed program applied to optimize the fixed address type ATC.

• International Journal of Computer Science & Network Security
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• v.23 no.5
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• pp.207-211
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• 2023

Traditional methods for datamining typically assume that the data is small, centralized, memory resident and static. But this assumption is no longer acceptable, because datasets are growing very fast hence becoming huge from time to time. There is fast growing need to manage data with efficient mining algorithms. In such a scenario it is inevitable to carry out data mining in a distributed environment and Frequent Itemset Mining (FIM) is no exception. Thus, the need of an efficient incremental mining algorithm arises. We propose the Distributed Incremental Approximate Frequent Itemset Mining (DIAFIM) which is an incremental FIM algorithm and works on the distributed parallel MapReduce environment. The key contribution of this research is devising an incremental mining algorithm that works on the distributed parallel MapReduce environment.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.782-785
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• 2002

Power amplifier of wireless communication tranceiver can be effectually controlled output power. And small size and low power dissipation are indispensable to portable system. In this paper, to reduce the size of portable tranceiver, inductor is integrated in a single chip. And to reduce power dissipation, a power amplifier that can be digitally controlled output power, is proposed and designed.

• Tribology and Lubricants
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• v.8 no.2
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• pp.73-79
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• 1992

The pressure distribution between the piston pad and the cylinder wall is analyzed to reduce the friction and to get the dynamic stability in the low friction piston. The calculated results indicate that the rectangular pad may reduce the friction in comparison to the square one. And the low friction piston can be stabilized when the pressure difference between the top and bottom of the piston skirt is very small.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.135-139
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• 2003

Sensor networks consist of sensor nodes with small-size, low-cost, low-power, and multi-functions to sense, to process and to communicate. Minimizing power consumption of sensors is an important issue in sensor networks due to limited power in sensor networks. Clustering is an efficient way to reduce data flow in sensor networks and to maintain less routing information. In this paper, we propose a multi-hop clustering mechanism using global and local ID to reduce transmission power consumption and an efficient routing method for improved data fusion and transmission.