• Journal of Advanced Navigation Technology
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• v.22 no.2
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• pp.64-69
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• 2018

Automatic test equipment for field maintenance of aircraft mounted equipment is effective for integrated design when operating a small number of aircraft for special purposes. The integrated automatic test equipment identifies commonly used interfaces and is used for branching or generating routes for each unit under test specific inspection. High-precision signals such as RTD, TC, and analog voltage can cause measurement errors due to conduction resistance during signal branching and connection when generating branches and paths. The measurement error caused by the resistance of the wire leads to a lot of restrictions in designing the equipment to be inspected. In this paper, we propose a method of calibrating highly accurate signals of an integrated automatic inspection equipment that minimizes measurement errors of analog voltage and high - precision signals.

• Transactions of the KSME C: Technology and Education
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• v.2 no.2
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• pp.89-97
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• 2014

The diesel driven power generation facility provides most of electricity of island region where is isolated from the main land power supply system. It is possible to extend the life of diesel driven power generation facility by periodic maintenance. However, the long-term use of diesel driven power generation facility increases the operating cost due to aging hardware and reduced plant efficiency. In other words, on-time replacement of aging diesel driven power generation facility reduces plant operation cost. The purpose of this study presents major indicators to represent the characteristics of the diesel generator and conducts sensitivity analysis using Monte Carlo analysis. In addition, status core which indicates quantitatively the state of the diesel driven power generation facility is defined and prepare the replacement criteria based on the state score.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.8
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• pp.1632-1638
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• 2011

Electric cables are one of the most important components in a nuclear power plant since they provide the power needed to operate electrical equipment. Despite their importance, cables typically receive little attention since they are considered passive, long-lived components that have been very reliable over the years when subjected to the environmental conditions for which they were designed. The operating experience reveals that a defect of the insulator or poor construction causes the initial failure of cable. However, the number of cable failures increase with plant aging, and these cable failures are occurring within the plants' 40-year licensed period. These cable failures have resulted in plant transients, shutdown, loss of safety functions or redundancy, entries into limiting conditions for operation, and challenges for plant operators. Therefore, diagnosis of MV cable installed in NPPs has become one of the most urgent issues in recent years. In accordance with PSR, condition maintenance for cables is also continuously required. Recently, HFPD tests have been widely performed to diagnose cable in the transmission and distribution cable system. However, on-line HFPD wasn't used in the NPPs because of the danger of plant shutdown, measurement sensitivity and application problems, etc. In this paper, HFPD measurement with portable device was performed to evaluate the integrity of the 4.16kV & 13.8kV cable lines. The test results show that HFPD is highly attractive to the diagnosis of MV cables in NPP by high detection sensitivity on-site.

• Journal of Home Health Care Nursing
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• v.10 no.1
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• pp.52-57
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• 2003

The purpose of this study was to evaluate appropriateness of home health care travel cost. For the evaluation, investigated the operating costs of vehicles used by home care nurses and then were components of home care nurses's annual salaries. Travel costs were then calculated based on actual travel expenses of home health care service. Actual data of 23 hospital-based home care agencies between July, 2002 to December, 2002 were collected for the analysis of the travel costs. The results of this study are : 1) For home visit, 65% of home care agencies turned out to be using only hospital owned cars, and 17.1% be depending purely on home care nurses' cars. On average, 1.9 cars used for home visit. 2) Out of 89 agencies, 23 agencies responded to the travel cost survey. Total maintenance cost of a car per month was 381,457 won. 3) Average per visit personal expenses of home care nurses during travel time turned out to be 7,124won assuming 8 working hours per day, 4 visits per day, and 30 minuets of travel time for each visit. 4) Total home health care travel cost per visit was 12,069 won, which was the sum of actually paid travel cost of 4,945 won and personal expenses during travel time of 7,124. In conclusion. we reckon that current compensation price of home care nurses' travel is inappropriate because total home health care travel costs of 12,069 won per visit turned out to be 2.1 times of currently prevailing standard compensation price of 5,830 per visit.

• The KIPS Transactions:PartD
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• v.9D no.4
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• pp.677-686
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• 2002

Recently, the Open-Development-Tool-Environment becomes a basic requirement of RTOS (Real Time Operating System) for embedded systems with restricted memory and CPU power in order to develop applications effectively. A remote interactive shell is one of the basic software components which makes users develop, test and control softwares without burdening target systems. In this paper, we have implemented the remote interactive shell with the following functions : loading object modules, spawning and manipulating tasks facilities thru a remote host. Comparing information reference methods with nonredundant overhead, we have achieved the system with easy maintenance. The shell has been developed with Q-PLUS RTOS under ARM EBSA285 target board and NT host.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1698-1700
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• 2003

The electrostatic precipitator(ESP) is a device for removing particulate pollutants in the form of either a solid (dust or fumes) or a liquid (mist) from a gas using an electrostatic force, Electrostatic precipitation has been widely used for cleaning gas from almost all industrial processes with a medium to large gas volume(>2,000 $m^3/min$), including utility boilers, blast furnaces, and cement kilns. ESP is also in wide use for air cleaning in living environments (home, offices, hospitals, etc.) ESP has large advantages over other particulate control device : a low operating cost, a high collection performance, and ease of maintenance. The purpose of this study is to investigate the characteristics of the smoke removal of an air cleaner by adjusting variable frequency and monitoring of turbidity three results of this research are as follows ;the first is the best efficient switching frequency which is 60Hz, the second is the smoke removal time which is obtained to 9 seconds, third is that the best efficient firing angle is $90^{\circ}$ As a result, the switching trigger frequency and SCR gate firing angle is very important factor to predict the best collection efficiency.

• Journal of the Korea Society for Simulation
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• v.31 no.2
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• pp.21-32
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• 2022

The ROK Navy is seeking to secure an aircraft carrier(CVX) to take responsibility for the maritime security of the Republic of Korea. In order for the CVX to complete the mission given to it, the crew must be able to operate the CVX perfectly, and for this purpose, the operating skills of the CVX crew result from constant training. Therefore, this paper proposes an On-board Training System(OBTS) so that the best training can always be performed even on ship. CVX OBTS should be built in the form of a thorough simulator based on a Synthetic Training Environment(STE) so that it can be optimally applied to ship and provide the best training environment to the crew. In order to satisfy the various training requirements and implementation conditions of the CVX, this paper proposes a plan to consist of Embedded Training System(ETS), VR training system, AR maintenance system, MR training system, MR metaverse training system, and realistic simulator training system.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.12
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• pp.1237-1244
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• 2016

Vehicle classification system in domestic tollgates is usually to use treadle sensor for calculating wheel width and tread of the vehicle. Due to the impact that occurs when the wheels of the vehicle contact, treadle sensor requires high durability. Recently, KHC(Korea Highway Corporation) began operating high-speed lane for cargo truck. High-speed cargo truck generate more impact the design criteria of previous treadle. Therefore, an increase in the maintenance and management costs of the treadle damage is concerned. In this paper, we propose an algorithm to classify vehicles using non-contact treadle sensors for improving durability from physical impacts. This was based on the KHC's classification criteria and showed a classification accuracy of 99.5 % in one experiment with 1892 vehicles through Changwon tollgate in 1020 local road. Therefore, it shows that vehicle classification system using non-contact treadle sensor could be applied to domestic toll tollgates, effectively.

• Journal of the Korean Society for Railway
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• v.14 no.3
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• pp.271-275
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• 2011

According to governmental policies for green growth, the increase in the traffic volume of railroad is a representative method to reduce total greenhouse gas (GHG) emitted from transport. Comprehensive assessment for the GHG emission of railroad has been studied to compare the difference of transport modes just in the operating step excluded the construction step. The purpose of this study was to evaluate GHG emissions in railroad construction sector. The targets were some construction works for civil, track, building, and electric system in A line. The GHG emission source of constructing railroad infrastructure was mainly the energy consumption of heavy equipments. As a result, the civil construction sector showed more than 96% of total GHG emissions and its specific GHG emission was 2.191 ton $CO_2e/m$. Also, the specific GHG emissions of civil construction works were of the order: earthworks > tunnels > bridges > station. In future, it will be required to calculate the overall GHG emission of railroad through life cycle approaches including operation, maintenance and disposal step.

• The Journal of Society for e-Business Studies
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• v.18 no.2
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• pp.47-67
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• 2013

With the emergence of indirect procurement, it has become a global trend for companies to outsource their maintenance, repair, and operating (MRO) supplies to procurement service providers (PSPs). Due to the variety of MRO items, evaluation of numerous suppliers in various industries is a particularly complex task for PSPs. Due to this complexity, many PSPs still evaluate and select suppliers based on the sourcing managers' subjective knowledge. Through the case of adopting a supplier evaluation system, this research is to find the managerial issues organizations should consider when they transform sourcing managers' knowledge into the system. We interpret the issues based on the Technology-Organization-Environment (TOE) framework. This case conclusively shows the importance of positive feedback loop between the users and the information system for the performance improvement of the system.