• The Journal of Engineering Geology
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• v.16 no.1 s.47
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• pp.23-30
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• 2006

This study was carried out to understand the relationship between orientation of tecto-lineaments obtained from aero-photograph and orientation of discontinuities measured at field for the rock types of igneous, sedimentary and metamorphic rocks in Andong area. Total 847 tecto-lineaments were extracted from the aero-photographs and total 1,940 discontinuities including joints, foliations and faults were measured during geologic survey. By using the software DIPS, preferred trends of tecto-lineaments were deduced as N30E-N40E for igneous rocks and N50E-N60E for both sedimentary and metamorphic rocks, while the trends of discontinuities were found as N40E-N50E for igneous rocks, N50E-N80E for sedimentary rocks and N50E-N60E for meta morphic rocks. Even though both orientations for a given rock type showed relatively good agreement in its trend, some discrepancy is also appeared. Since construction safety of geo-structures such as tunnel and slope, etc., is significantly affected by the orientation of discontinuities in rock masses, it is highly recommended to perform a detailed geologic survey as well as an aero-photograph interpretation at a design stage.

• International Journal of Aeronautical and Space Sciences
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• v.1 no.1
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• pp.48-61
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• 2000

Korea Aerospace Research Institute (KARI) have gained experience with Helicopter Vibration Health Monitoring (VHM) System technology with the help of UK GKN-WHL. GKN-WHL have had many years of experience with the research and development of vibration analysis techniques to improve the health monitoring of helicopter transmissions. This activity was targeted at transmission rig testing at first, but the techniques have been progressively developed where they are now used as a part of integrated Health and Usage Monitoring (HUM) systems on many types of in-service and new helicopters. The technique development process has been considerably aided by an ever expanding database of transmission monitoring experience from both the rig testing and aircraft operations. This experience covers a wide range of failure types from naturally occurring faults to crack propagation studies and covering a wide range of transmission configurations. Primarily based on accelerometer signals GKN-WHL's vibration analysis methods have also been applied to a variety of other sensor types. The transition from an experimental environment to operational VHM systems has been a lengthy process, there being a need to demonstrate technique reliability as well as effectiveness to both regulatory (Airworthiness Authority) and commercial organizations. Another important feature of this process has been the development of close relationships with a number of VHM system hardware and software suppliers. Such an experienced GKN-WHL provides various raw vibration data which was acquired from transmission ground test rig and allow KARI to develop it's own analysis program. KARI made a program and then analyzed the data to coma pre with the results of GKN-WHL. The KARI's results both time domain signals and statistical values show comparable to GKN's.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.2
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• pp.65-70
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• 2015

In the PCB(Printed Circuit Board) manufacturing industry, the yield is an important management factor because it affects the product cost and quality significantly. In real situation, it is very hard to ensure a high yield in a manufacturing shop because products called chips are made through hundreds of nano-scale manufacturing processes. Therefore, in order to improve the yield, it is necessary to analyze main fault process and equipment that cause low PCB yield. This paper proposes a systematic approach to discover fault-causing processes and equipment by using a logistic regression and a stepwise variable selection procedure. We tested our approach with lot trace records of real work-site. A lot trace record consists of the equipment sequence that the lot passed through and the number of faults for each fault type in the lot. We demonstrated that the test results reflected the real situation of a PCB manufacturing line.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.1
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• pp.145-151
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• 2017

In this paper, we propose the design and implementation of the system that is predicting the failure of ballast water treatment system by analysing its sensor datum and is reserving the most effective service center for sellecting the repair location on the way to the destination port. These data are collected in real time during draining or filling up the sea water from/to the ship, and it is essential to preliminarily repair the equipment showing unstable characteristics by analyzing the normal and abnormal data characteristics. We proposed a software platform for predicting and repairing faults by selecting the most efficient repair center based on this e-Navigation while the vessel is navigating to the next destination port. This system, as announced by the IMO Convention for the Prevention of Marine Pollution in 2017, provides a stable economic impact from stable cargo operation and stable out/in from/to port and marine ecosystem.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.5248-5255
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• 2014

Because of the rapid growth of smart phone market, the number of mobile applications has increased exponentially. As mobile applications are developing at a rapid rate, many of them are being developed without considering a systematic development process or quality factors, such as reusability, extensibility, etc.. As a result, they have many faults internally, they are being underrated in satisfaction or reliability from customers, and finally customers do not update or repeat the purchase. Therefore, a meta-model of development process for mobile applications was designed to improve the continuous usability of mobile applications as well as the satisfaction and reliability from users. Applying development process based on a meta-model to mobile application development is expected to improve development productivity and quality of mobile applications.

• The Journal of the Korea Contents Association
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• v.8 no.8
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• pp.37-46
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• 2008

Launch control system controls the sequence for launching missile in weapon systems. This system have to generate the engagement plan, input information and launch the missile in timeliness requirement. Such a system may fail to operate correctly either due to errors in hardware and software or due to violation of timing constraints. We presented fault-tolerant ethernet for embedded real-time system like launch control system. This approach is designed to handle network faults using dual commercial-off-the-shelf(COTS) network devices. To support fault-tolerant ethernet each node is composed dual channel ethernet and designed the communication middleware for network fault detect and recovery. Especially for time-critical system, the middleware is being developed to achieve that no point of network failure shall take down or cause loss of communication to network nodes.

• Journal of the Korea Convergence Society
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• v.8 no.3
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• pp.191-197
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• 2017

This development is for non-destructive machine using X-Ray source about detecting outline faults of below middle size products. The differentiation is product of research and development unspecialized small and medium-sized products using X-Ray light sources can check real time if the surface of an external fault of radiation dose reference, within the leakage. The speed control is possible by software solution. In addition, we're working on possibly block doors for worker safety and equipment at the same time that inner drive can be identified in the image. These principles, as a key enabler of the current inspection system such as the container is small to medium-sized parts - a long way from utilization level is possible. This research will give rise to major effects for other various non-destructive market industries except car-industry. The most important fact is that this developed non-destructive machine is controlled below $0.2micro-S{\mu}v$.

• The KIPS Transactions:PartD
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• v.8D no.6
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• pp.753-760
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• 2001

Design Patterns are design knowledge for solving issues related to extensibility and maintainability which are independent from problems concerned by application, but despite vast interest in design pattern, the specification and application of patterns is generally assumed to rely on manual implementation. As a result, we need to spend a lot of time to develop software program not only because of being difficult to analyze and apply to a consistent pattern, but also because of happening the frequent programing faults. In this paper, we propose a notation using XML for describing design pattern and a framework using design pattern. We will also suggest a source code generation support system, and show a example of the application through this notation and the application framework. We may construct more stable system and be generated a compact source code to a user based on the application of structured documentations with XML.

• Journal of Information Technology Services
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• v.11 no.4
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• pp.251-262
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• 2012

Unit testing is one of the test levels, which tests an individual unit or a group of related units. Recently, in Agile Development or Safety-critical System Development, the unit testing plays an important role for the qualities. According to the definition of unit testing, it is supposed to be done by the developers of units. That is because test models for the unit testing refers to the structure of units, and others but its original developers hardly can understand the structures. However, in practice, unit testing is often asked to be done without the original developers. For example, it is when faults are revealed in customer sites and the development team does not exit any more. In this case, instead of original developers, other developers or test engineers take a product and test it. The unit testing done by a non-developer, who is not the original developer, would cause some difficulties or cause more cost. In this paper, we tests an open source, JTopas, as a non-developer, with building test models, implementing test codes, and executing test cases. To fit this experiment to practical testing situations, we designed it based on the practices of unit testing, which were surveyed through SPIN(Software Process Improvement Network). This paper analyzes which part of unit testing done by non-developers needs more effort compared to the unit testing done by original developers. And it concludes that Agile Development contributes on reducing the extra effort caused by non-developers, since it implements test codes first before developing source code. That means all the units have already included their own tests code when they are released.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.16-21
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• 2008

Aero-engine, as one kind of rotating machinery with complex structure and high rotating speed, has complicated vibration faults. Therefore, condition monitoring and fault diagnosis system is very important for airplane security. In this paper, a vibration data acquisition and intelligent fault diagnosis system is introduced. First, the vibration data acquisition part is described in detail. This part consists of hardware acquisition modules and software analysis modules which can realize real-time data acquisition and analysis, off-line data analysis, trend analysis, fault simulation and graphical result display. The acquisition vibration data are prepared for the following intelligent fault diagnosis. Secondly, two advanced artificial intelligent(AI) methods, mapping-based and rule-based, are discussed. One is artificial neural network(ANN) which is an ideal tool for aero-engine fault diagnosis and has strong ability to learn complex nonlinear functions. The other is data mining, another AI method, has advantages of discovering knowledge from massive data and automatically extracting diagnostic rules. Thirdly, lots of historical data are used for training the ANN and extracting rules by data mining. Then, real-time data are input into the trained ANN for mapping-based fault diagnosis. At the same time, extracted rules are revised by expert experience and used for rule-based fault diagnosis. From the results of the experiments, the conclusion is obvious that both the two AI methods are effective on aero-engine vibration fault diagnosis, while each of them has its individual quality. The whole system can be developed in local vibration monitoring and real-time fault diagnosis for aero-engine.