• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.679-681
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• 2005

The materials for transmission line construction were transported by road which opened in mountainous areas until the mid 1990s, However, from the mid 1990s, as social interest in the environment standard increases, a cable way and helicopter transport methods of construction have been applied to minimize damage to the environment and to build an environmental friendly system. The current cable way method is a single cable way system which has a lower section base to load materials into a carriage and carry them to the tower construction site by use of an engine and a main rope. Then the carriage lowers itself via a slope between the tower construction site and the lower section base. The single cable way system has the demerits of site acquisition for the lower section base, forest felling when installing the wire rope, and it is not applicable to a even topology Also it has to be installed separately at each tower site. Accordingly, to carry materials without forest felling and regardless of slope, the chain cable way system was developed to provide materials for more than two towers consecutively by use of an engine carriage and winch.

• Journal of the Korean Society for Railway
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• v.9 no.2 s.33
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• pp.230-236
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• 2006

For a short-term measurement to reduce an accident on a railroad crossing, it is necessary to find out the weakness and problems of existing equipment in the railroad transportation system. The analysis of railroad crossing accidents shows that main causes of accidents (24.9%) are the careless driving including an engine problem, damage on the safety equipment, slide on the snow, and an engine stop on the railroad crossing. Therefore, it is required to install a sensor, or to make a crossing gate at the exist for detecting obstacles on a railroad to prevent collisions among trains. This paper suggests 'a panel sensor using the strain gauge' to make up the weaknesses of the sensing Dead Zone, which are caused by using a laser method, and to detect any small objects passing railroads in order to reduce the errors, which are occurred in the earth magnetic field for controlling Exit Slide Crossing Arm Detector. The device, suggested in this paper, is verified with detecting any small objects passing the railroad, with judging entry decision clearly, and with controlling passing gate and obstruction warnings/cautions obstacles at the same time, through an experimental test.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.3
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• pp.303-307
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• 1990

In this paper, the factors of 1680 marine casualties occurred during 1986-1988 are analysed by the Principal Component Analysis. The main results are as follows: 1. Most of marine casualties result from the human factors such as careless operation and insufficient engine maintenance. Engine trouble is main part of accidents and great number of accidents is rated for fishing vessels. 2. Accidents are serious in case of cargo ships, passenger ships and tankers from the point of view of the damage of human life and properties. On the other hand, those are not so serious matter in case of fissing vessels and governmental vessels. 3. Grounding, collision and capsizal mainly result from careless operation, however material defect result in flooding

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.12
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• pp.7-14
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• 2019

A marine turning gear controls the position of the piston-crank mechanism by rotating the flywheel of the marine engine at a low speed, which is the main auxiliary machine that enables the disassembly and maintenance of the engine. In this study, the safety factor for surface durability and tooth bending strength was improved by the design modification of the marine turning gear based on the spur planetary gear. Angular velocity, torque, and efficiency of the turning gear were measured using a reliability evaluation tester, and a multibody dynamics model for analysis corresponding to the test results was developed. Finally, it was confirmed that the design improvements improved the tooth surface damage of the sun gear in the 3^rd reduction stage.

• Tribology and Lubricants
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• v.24 no.6
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• pp.285-290
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• 2008

The purpose of this paper is to present the case study of tribological failure analysis on the gear damages, oil leakage, and sealant sealing in a manual transmission of front engine and front wheel drive vehicle. The manual transmission is to change the speed range and direction of the engines depending on the driving conditions by friction driving forces with input and output gear system. The material property and surface roughness of the gears are strongly related to the gear noise and micro-vibration, oil leakage and wear, which may decrease the real contact area of the gear and the strength of the oil film thickness between the driving gear and driven one. The O-ring damage of speedometer driven gear and bad sealant sealing of oil pan may produce oil leakage through the contact surfaces, which cause the oil shortage and seizure on the sliding surfaces of the transaxle gears. In the failure case study, the proper repair working and good lubrication are very important for the long life of the transaxle without any tribological failures and oil leakage.

• Nuclear Engineering and Technology
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• v.43 no.5
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• pp.413-420
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• 2011

In Korea, although the concept of dry storage system for PWR spent fuels first emerged in the early 1990s, wet storage inside nuclear reactor buildings remains the dominant storage paradigm. Furthermore, as the amount of discharged fuel from nuclear power plants increases, nuclear power plants are confronted with the problem of meeting storage capacity demand. Various measures have been taken to resolve this problem. Dry storage systems along with transportation of spent fuel either on-site or off-site are regarded as the most feasible measure. In order to develop dry storage and transportation system safety analyses, development of design techniques, full scale performance tests, and research on key material degradation should be conducted. This paper deals with two topics, structural analysis methodology to assess cumulative damage to transportation packages and the effects of an aircraft engine crash on a dual purpose cask. These newly emerging issues are selected from among the many technical issues related to the development of transportation and storage systems of spent fuels. In the design process, appropriate analytical methods, procedures, and tools are used in conjunction with a suitably selected test procedure and assumptions such as jet engine simulation for postulated design events and a beyond design basis accident.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.3
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• pp.120-126
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• 2005

The method of decreasing the ecological risk for the LRE(Liquid Rocket Engine) test is developed, working on the cryogenic oxidizer and the high-boiling fuel(Kerosene). This Method is based on the study that contains a technical solution method and an accident occurrence range for decreasing of accident probability and damage. This paper contains schematic on the all risk circumstance bring to accident, block-diagram for an accident growth process in case of the propellant leakage, technical solution method and risk reduction evaluation method. It will be used to alternative method for the risk reduction of complex technical systems.

• 유체기계공업학회:학술대회논문집
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• 1999.12a
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• pp.301-308
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• 1999

The present study investigates numerically particle laden flow through compressor cascades and a rocket nozzle. Engines are affected by various particles which are suspending in the atmosphere. Especially in the case of aircraft aviating in volcanic, industrial and desert region including many particles, each components of engine system are damaged severely. That damage modes are erosion of compressor blading and rotor path components, partial or total blockage of cooling passage and engine control system degradation. Numerical prediction and experimental data, erosion rates are predicted for two materials - ceramic, soft metal - on compressor blade surface. Aluminum oxide ($Al_2O_3$) Particles included in solid rocket propelant make ablative the rocket motor nozzle and imped the expansion processes of propulsion. By the definition of particle deposition efficiency, characteristics of particles impaction are considered quantitatively Stoke number is defined over the various particle sizes and particle trajectories are treated by Lagrangian approach. Particle stability is considered by definition of Weber number in rocket nozzle and particle breakup and evaporation is simulated in a rocket nozzle.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.299-302
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• 2010

Recently, the malicious code is not easily detectable in the vaccine for the virus, malicious code as a compressed file by modulation pattern is the tendency to delay. Among the many antivirus engines on the market a compressed file that can be modulated by malicious code, and test whether the pattern will need to know. We cover a multi-compressed files, malicious code modulated secreted by examining patterns of test engine is being detected is through a computer simulation. Analysis of secreted activities of malicious code and infect the host file tampering with the system driver files and registry, it gets registered is analyzed. this study will contribute hidden malicious code inspection and enhance vaccine efficacy in reducing the damage caused by malicious code.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.117-122
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• 2012

A blisk with rotor shroud is usually adopted in LRE turbine to maximize its performance. However it experiences severe thermal load and resulting damage during engine stating and stop. Shroud splitting is devised to relieve thermal stress on the turbine rotor. Structural analysis confirmed the reduction of plastic strain at the blade hub and tip. However, split gap at the rotor shroud entails additional tip leakage and results performance degradation. In order to assess the effect of shroud split on the turbine performance, tests have been performed for various settings of shroud split. For the maximum number of shroud splitting, measured efficiency reduction ratio was 2.65% to the value of original shape rotor.