• Journal of the Korean Society for Railway
• /
• v.10 no.3 s.40
• /
• pp.355-364
• /
• 2007

Recently a concrete slab tracks are being constructed on roadbed in the Gyoeng-bu 2nd phase high speed railways. In respdnding to this trend, new design standards and track materials maintenance systems, based on the slab track material safety and usage perspective, are needed. This research provides a roadbed design criteria and the maintenance system. The proposed roadbed design criteria and the maintenance system are based on the developed analysis meathod of train/slab-track interaction. where the roadbed settlement and train speed are utilized as mediating variables. In the analysis, the dynamic response of train/slab-track interaction apply to various speeds and settlements. the roadbed settlement is shown in a sinusoidal shape of wave, the scope of the settlement occurrence presented in its wavelengths, include 6meters, 10meters, 15merwes, 20meters, 30meters. The train speeds involved are 50, 100, 150, 200, 250, 300, 350, 400kilometers per hour.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2004.05a
• /
• pp.1433-1436
• /
• 2004

The ad hoc network is a collection of wireless mobile nodes dynamically forming a temporary network without the use of any existing network infrastructure of centralized administration. Load-Balanced Ad hoc Routing(LBAR) protocol is an on-demand routing protocol intended for delay-sensitive applications where users are most concern with packet transmission delay. Although LBAR mechanism is a novel load balancing routing protocol for ad hoc network, it has own limitation in route path maintenance phase. Therefore, in this paper, we propose Advanced Load-Balanced Ad hoc Routing(A-LBAR) that is delay-sensitive and has an efficient path maintenance scheme. The robust path maintenance scheme is maintained by considering about nodal loads all over network and misbehavior of overloaded or selfish nodes. The proposed scheme provides good performance over DSR and AODV in terms of packet delay and packet loss rate when some misbehaving nodes exist in the network.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.07a
• /
• pp.443-446
• /
• 2002

In this paper, a phase difference of liveline insulator was measured and analyzed to estimate the contamination degree. The probability of accident rises according to the increase of the contamination. So the estimation of contamination degree is very important in design and maintenance of outdoor insulator. There are many methods to measure the contamination degree, but those methods use the spacial sense to measure the contamination degree. So, we have no information about the contamination from the liveline insulator, but there is a measurement of phase difference to estimate the contamination degree. The phase difference is varied with the increase of ESDD, so the contamination degree could be estimated by using those characteristics. The experiment is performed to analyze the interrelationship between contamination degree and phase difference. The variable condition is relative humidity that increases from 30 to 100 % in a chamber. We use the DAS program to measure and analyze the data. From the result, the variation of phase difference is different by the contamination degree, so we can confirm the possibility of estimating the contamination degree by the phase difference.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.35 no.4
• /
• pp.961-968
• /
• 2015

As BIM has been increasingly applied to building project recently, its application to civil engineering project is also on the rise. As construction structures have been expanded and complicated in a size and type, the information for handling maintenance process has also increased. Thus, to actively utilize the BIM information created at the design stage, this study has been carried out to establish a maintenance system using a marker-less based augmented reality method, by presenting a maintenance system for the construction structures using augmented reality. A SURF algorithm is used to link the 3D objects in the design and construction phases to the maintenance phase. The presented method in this study can increase the utilization of 3D information created at the design stage, by offering an augmented reality technology at the maintenance stage. The method could also improve the efficiency of visual inspection on construction structures by augmenting 3D model of a bridge structure.

• Journal of Ocean Engineering and Technology
• /
• v.26 no.5
• /
• pp.63-72
• /
• 2012

The product lifecycle of a marine vessel can be classified into the design-production, operation-maintenance, and disposal phases. During the operation and maintenance phase, status data should be gathered from the major machinery and instruments installed on the marine vessel in order to perform efficient maintenance work. Although a PLM (product lifecycle management) system can manage the product information during the design and assembly stage, a PLM based on asset management technology is more appropriate for product information management during the operation stage. Product embedded information devices (PEIDs) are suggested for gathering real-time maintenance information during the operation and maintenance lifecycle. A PEID allows PLM to provide the capability of offering active information exchange between the lifecycle management system and equipment. This study designed a PEID to effectively obtain information and interact with a PLM system. It consists of sensors, wireless communication, and a micro-processor, which allow it to accumulate status data on the PLM system. The embedded information device and PLM enable the seamless information flow, tracking, and updating of MRO (maintenance repair and overhaul) information for a product throughout the middle of the product lifecycle.

• Journal of the Korea Institute of Building Construction
• /
• v.18 no.6
• /
• pp.621-631
• /
• 2018

The repair and maintenance cost of domestic public rental housing is an issue of considerable interest and growing financial concern. This paper suggests a quantity-based model as an alternative method for predicting costs, instead of the conventional model which is based on actual cost data. Furthermore, this paper provides a forecast of the repair costs incurred each year during the multi family house's maintenance phase (40 years). The recently changed the long-term repair plan and quality-improved interior materials were considered into the research. In order to estimate the cost of maintenance work, 5 sample apartments were selected and analyzed. The repair and maintenance cost from the case studies was converted to cost per household and per floor area for general use. On the other hand, the net present value method was applied to reflect the effect of time. We expect that the results will help to establish expenditure plans that are more effective for public rental housing in the maintenance stage.

• The Journal of Information Systems
• /
• v.15 no.2
• /
• pp.153-171
• /
• 2006

The objective of this research project is empirically investigating factors influencing EPP system implementation based on the degree of volatility of business environment. The results show that computes with low volatility have successfully implement ERP system compared to companies with high volatility. This research project also identified success factors of each phased chartering phase, executive participation sound assessment of business condition, good understanding of ERP system and carefully constructed case are identified as success factors. During project expenditures, participation of various groups, technical resources, prefect and change management are found to be important for successful construction. Trained users, integration of systems, well-designed process and technical and human resource are found to be success factors during shakedown phase. Managers commitment technical infrastructure, system flexibility, and adequate resource for maintenance and renewing system are identified as success factors of onward and upward phase.

• Proceedings of the KIPE Conference
• /
• 2002.07a
• /
• pp.205-208
• /
• 2002

The single phase induction motor(SPIM) with two windings, main and auxiliary winding, is widely used due to ruggedness, low maintenance and simplicity of construction. There are several ways of starting single phase induction motor. The most common method is to use centrifugal switch that is connected in series with a capacitor. But the centrifugal switch that is the external starting system has many problems. In this paper, we use triac to overcome defects that happen by centrifugal switch, Also we used inductor that connected with main winding to get a gate trigger voltage signal. Experiments are focused on a capacitor starling single phase induction motor.

• Physical Therapy Korea
• /
• v.1 no.1
• /
• pp.83-87
• /
• 1994

The purpose of this paper is to provide an overview of the clinical physical therapy program used at the University of Yonsei Rehabilitation Hospital, for the practicing university trained physical therapists who may be unfamiliar with patients who have suffered a myocardial infarction. The four primary phases of the cardiac physical therapy graded exercise program are: 1) coronary care unit program (phase I), 2) general ward program (phase II), 3) convalescence program (phase III), 4) maintenance program (phase IV). The exercise prescription defines the exercise intensity, duration, frequency, and mode of exercise a after pre- discharge low level graded exercise test(LL-GXT) or symptom limited maximum graded exercise test. A typical exercise routine consists of preparation warm-up exercise, therapeutic exercise, cool-down exercise. Physical therapy is involved in the acute care and rehabilitation of the patient after a myocardial infarction. Therefore, the physical therapist must throughly comprehened the cardiac anatomy, cycle, performance, conduction system, pathogenesis, risk factors, and exercise benefits.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.11B no.2
• /
• pp.22-27
• /
• 2001

Salient pole rotor type single phase switched reluctance motor is of simple and rigid structure, short shaft and simple driving circuit. Especially, the output power per unit volume of salient pole rotor structure is comparatively high because the magnetic fluxes of axial and radial direction are simultaneously used. Therefore, this motor will be used at small space and difficult maintenance situations. In this paper, the selecting method of proper pole arc, stator, and rotor dimension of salient pole rotor type single phase SRM is proposed.