• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.17 no.1
• /
• pp.39-45
• /
• 2009

An Analysis of wind is essential for planning runway direction. As a general rule, the principal traffic runway at an airport should be oriented as closely as practicable in the direction of the prevailing wind. Aircraft are able to maneuver on a runway as long as the wind component at right angles to the direction of landing and taking-off, the cross wind component, is not excessive. ICAO recommends that runway be oriented so that aircraft may be landed at least 95% of the time with allowable cross wind components not exceeding specified limits based upon the airport reference field length. Based on the recommendation, the direction of the runway or runways at an airport can be determined through graphical vector analysis on wind rose. This study is to develop the wind-rose software for planning the optimum runway direction at an airport with the raw wind data based on reliable wind distribution statistics that extend over as long as a period as possible, preferably of not less than 5 years.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.8
• /
• pp.842-847
• /
• 2010

Thermal analysis for the simulation of satellite component level thermal vacuum test processes was carried out by considering thermal vacuum test environment condition, thermal vacuum chamber configuration, and satellite's inner thermal environment. The transient analysis results can be obtained for the temperatures of component and thermal vacuum chamber assemblies. The thermal analysis model was verified with the component thermal environmental test results by using enhanced thermal vacuum chamber.

• Journal of Internet Computing and Services
• /
• v.7 no.6
• /
• pp.41-50
• /
• 2006

In order to improve software development productivity and quality, reuse approaches and supporting library systems have been proposed. Library systems have applied various methods to classify, store, retrieve, and comprehend reusable components effectively. As the number of library systems grows, it is difficult to categorize, compare and analyze existing reuse libraries. In this paper, we present classification criteria for reuse library systems. A set of criteria is defined by integrating facet-based and attribute-based classification methods which encode the properties of a reusable component. In order to show the usefulness of the proposed classification criteria, representative library systems based on application domains, as well as component classification methods ore selected and reviewed. We then classify these library systems according to the proposed criteria.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.9 no.3
• /
• pp.75-81
• /
• 2009

In this paper, we propose component modeling method using object-oriented design information. it will be supplied to simplify and specify the relationship between informations that to be developed technology based on clustering, encapsulation and inheritance concepts. Also, we propose abstraction method, it will be support to understanding information relation, and it can modeling on system level without particular domain through dividing common service by reuse unit. Thus It is possible reusability and scalability by this concept, and shorten development period and enhance quality.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.7 no.1
• /
• pp.195-201
• /
• 2012

Environmental information monitoring system with a control system and a sensor node transfers real-time collected data from sensor node to the remote control system. Operability of the control system can significantly decrease depending on its operating environment, type of sensor and the number of sensor installed on the sensor node and the communication environment between the control system and sensor node. In this study, we proposed and implemented component-based environmental information monitoring system using the appropriate components depending on operating environment in order to increase operational efficiency.

• Journal of Electrical Engineering and Technology
• /
• v.7 no.6
• /
• pp.814-823
• /
• 2012

Electric power transmission utilities make an effort to maximize profit by reducing their electricity supply and operation costs while maintaining their reliability. The development of maintenance strategies for aged components is one of the more effective ways to achieve this goal. The reliability centered approach is a key method in providing optimal maintenance strategies. It considers the tradeoffs between the upfront maintenance costs and the potential costs incurred by reliability losses. This paper discusses the application of the Particle Swarm Optimization (PSO) technique used to find the optimal maintenance strategy for a transmission component in order to achieve the minimum total expected cost composed of Generation Cost (GC), Maintenance Cost (MC), Repair Cost (RC) and Outage Cost (OC). Three components of a transmission system are considered: overhead lines, underground cables and insulators are considered. In regards to aged and aging component, a component state model that uses a modified Markov chain is proposed. A simulation has been performed on an IEEE 9-bus system. The results from this simulation are quite encouraging, and then the proposed approach will be useful in practical maintenance scheduling.

• Journal of the Korean Society of Safety
• /
• v.18 no.4
• /
• pp.164-168
• /
• 2003

Bayes theorem, suggested by the British Mathematician Bayes (18th century), enables the prior estimate of the probability of an event under the condition given by a specific This theorem has been frequently used to revise the failure probability of a component or system. 2-Stage Bayesian procedure was firstly published by Shultis et al. (1981) and Kaplan (1983), and was further developed based on the studies of Hora & Iman (1990) Papazpgolou et al., Porn(1993). For a small observed failure number (below 12), the estimated reliability of a system or component is not reliable. In the case in which the reliability data of the corresponding system or component can be found in a generic reliability reference book, however, a reliable estimation of the failure probability can be realized by using Bayes theorem, which jointly makes use of the observed data (specific data) and the data found in reference book (generic data).

• Journal of Drive and Control
• /
• v.16 no.2
• /
• pp.43-50
• /
• 2019

The objective of this study was to reverse engineer a swash plate type piston pump mounted on a wheeled armored vehicle and to analyze the structure of the pump case. From the analysis, the weak parts were identified and corrected in the final design. Each element corresponding to the piston pump case was analyzed. The analytical method was given static boundary conditions, load conditions and confirmed displacement, strain, stress, and safety factor. Plastic deformation and damage were also confirmed and the component elements redesigned through structural analysis Structural analysis and vibration analysis were carried out for the components of the piston pump case. The piston pump model was finally modified by structural analysis and vibration analysis results for each component assembly, and a prototype was designed. Durability test and environmental test were carried out and the test results satisfied all of the requirements. Therefore, the analytical method presented in this study can be utilized as a methodology for element component design in the development of various piston pumps.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.14 no.3
• /
• pp.513-518
• /
• 2019

The non-destructive testing equipment using an eddy current was developed to check for defect in the vehicle transmission component. A defect master sample was made to test all types of defects that occur in the component and also an eddy current detector was manufactured and used to test and detect all kinds of defects. In addition, testing was held against the actual defective items to investigate the cause and type of defects, and a comparative study was conducted based on results from the examination. The software system of the eddy current detector was developed so that even a non-specialist can make assessment of detect in the component from the test results displayed on the monitor.

• Journal of Korean Society of Water and Wastewater
• /
• v.33 no.2
• /
• pp.159-167
• /
• 2019

In this paper the potential of the principal component analysis(PCA) technique for the application of detecting leaks in water pipe networks was evaluated. For this purpose the PCA was conducted to evaluate the relevance of the calculated outliers of a PCA model utilizing the recorded pipe flows and the recorded pipe leak incidents of a case study water distribution system. The PCA technique was enhanced by applying the computational algorithms developed in this study which were designed to extract a partial set of flow data from the original 24 hour flow data so that the effective outlier detection rate was maximized. The relevance of the calculated outliers of a PCA model and the recorded pipe leak incidents was analyzed. The developed algorithm may be applied in determining further leak detection field work for water distribution blocks that have more than 70% of the effective outlier detection rate. However, the analysis suggested that further development on the algorithm is needed to enhance the applicability of the PCA in detecting leaks by considering series of leak reports happening in a relatively short period.