• International Journal of Aeronautical and Space Sciences
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• v.9 no.2
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• pp.64-70
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• 2008

The UAV propulsion system that will be operated for long time at more than 40,000ft altitude should have not only fuel flow minimization but also high reliability and durability. If this UAV propulsion system may have faults, it is not easy to recover the system from the abnormal, and hence an accurate diagnostic technology must be needed to keep the operational reliability. For this purpose, the development of the health monitoring system which can monitor remotely the engine condition should be required. In this study, a fuzzy trend monitoring method for detecting the engine faults including mechanical faults was proposed through analyzing performance trends of measurement data. The trend monitoring is an engine conditioning method which can find engine faults by monitoring important measuring parameters such as fuel flow, exhaust gas temperatures, rotational speeds, vibration and etc. Using engine condition database as an input to be generated by linear regression analysis of real engine instrument data, an application of the fuzzy logic in diagnostics estimated the cause of fault in each component. According to study results. it was confirmed that the proposed trend monitoring method can improve reliability and durability of the propulsion system for a long endurance UAV to be operated at medium altitude.

• Journal of the Korean Ceramic Society
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• v.46 no.2
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• pp.161-169
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• 2009

MLCC (Multi-layer Ceramic Capacitor) is the most important passive component in electronic devices such as HHP, PC and digital display. The development trend of MLCC is a miniaturization with increasing the capacitance. In this paper, a development history of the high capacitance MLCC in Korea was introduced, and the necessity of the finer $BaTiO_3$ was explained in the viewpoint of the issued electrical and dielectric properties of high capacitance MLCC. The bottleneck technologies to realize the high capacitance was shortly introduced, followed by the prediction of the development trend of MLCC in near future.

• Proceedings of the Korea Information Processing Society Conference
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• 2018.05a
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• pp.562-565
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• 2018

A wide range of IoT applications use information collected from networks of sensors for monitoring and controlling purposes. However, the frequent appearance of fault data makes it difficult to extract correct information, thereby sending incorrect commands to actuators that can threaten human privacy and safety. For this reason, it is necessary to have a mechanism to detect fault data collected from sensors. In this paper, we present a trend-adaptive multi-scale principal component analysis (Trend-adaptive MS-PCA) model for data fault detection. The proposed model inherits advantages of Discrete Wavelet Transform (DWT) in capturing time-frequency information and advantages of PCA in extracting correlation among sensors' data. Experimental results on a real dataset show the high effectiveness of the proposed model in data fault detection.

• Electrical & Electronic Materials
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• v.8 no.4
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• pp.509-517
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• 1995

• Journal of Korea Foundry Society
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• v.27 no.1
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• pp.20-23
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• 2007

• The Journal of Information Systems
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• v.12 no.1
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• pp.87-116
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• 2003

One of the important applications for business-to-business electronic commerce is in procurement and inventory management using electronic data interchange(EDI). Using online catalogs and approved supplier lists, firms can easily create requisitions and purchasing documents. The emerging trend in EDI technology is changed from VAN(Value Added Network) based EDI to XML based EDI. This paper intends to suggest a component-based XML/EDI system using Unified Modeling Language(UML), as an application system for automobile part industry. Applying component based XML/EDI systems designed with UML methodology, we analyzed the workflow and the document on procurement process between trading partners and implemented a prototype of efficient XML/EDI system, as a surrogate of existing VAN/EDI. The result of applying object-oriented CBD(Component Based Development) technique is to minimize the risk of life cycle and facilitate the reuse of software as mentioned to limitation of information engineering methodology. It enables the interoperability with corporate legacy systems such as ERP(Enterprise Resource Planning), SCM(Supply Chain Management). This system proposes a solution to apply analysis phase and design phase in implementation of XML/EDI system. The implementation of XML/EDI system using CBD shows the ease of use in software reuse and the interoperability with corporate internal information system. The purchasing department with XML/EDI system can electronically communicate purchase orders, delivery schedules to external suppliers and interoperate with other application systems.

• Management Science and Financial Engineering
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• v.14 no.2
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• pp.105-118
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• 2008

There are many debates on the topic of the relationship between oil prices and economic growth. Through the repeated processes of conformations and contractions on the subject, two main issues are developed; one is how to define and drive oil shocks from oil prices, and the other is how to specify an econometric model to reflect the asymmetric relations between oil prices and output growth. The study, thus, introduces the unobserved component model to pick up the oil shocks and a first-order Markov switching model to reflect the asymmetric features. We finally employ unique oil shock variables from the stochastic trend components of oil prices and adapt four lags of the mean growth Markov Switching model. The results indicate that oil shocks exert more impact to recessionary state than expansionary state and the supply-side oil shocks are more persistent and significant than the demand-side shocks.

• Proceedings of the ESK Conference
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• 1995.10a
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• pp.240-248
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• 1995

In Korea, it is not satisfactory in the product design since Kansei engineering or Ergnomics is not very active and well considered. When designing a mini-component, the user's emotion was not considered well. It is typical to have a rectangular shape, dark- colored outside in a mini-component design. Therefore, the users have to select with available choice from the manufacture's traditional designs. In this study, a new smin- component was designed to be suitable for a new generation's (10 to mid-20) sensation. First of all, an ergonomic problems were investigated. And then, the survey was per- formed to consider the emotion of the new generation. After that, the new design was made to reflect the new generation's trend and preference. In addition, the high-touch (human-centered design) and human touch (the product to give a sensible satisfaction for human) concepts were added.

• Korean Management Science Review
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• v.20 no.1
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• pp.103-124
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• 2003

The seasonal adjustment is an essential process in analyzing the time series of economy and business. There are various methods to adjust seasonal effect such as moving average, extrapolation, smoothing and X11. One of the powerful adjustment methods is X11-ARIMA Model which is popularly used in Korea. This method was delivered from Canada. However, this model has been developed to be appropriate for Canadian and American environment. Therefore, we need to review whether the Xl1-ARIMA Model could be used properly in Korea. In this study, we have applied the method to the annual sales of refrigerator sales in A electronic company. We appreciated the adjustment by result analyzing the time series components such as seasonal component, trend-cycle component, and irregular component, with the proposed method.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2289-2295
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• 2015

The paper presents the incidence rates of malignant tumors of the central nervous system assessed by the component analysis. The data on primary registered cases of malignant tumors of the central nervous system in the country were used as the material of the study for the period from 2004 to 2011. A general trend of increase in the number of patients with malignant tumors of the central nervous system in Kazakhstan was determined and the potential of their increase was evaluated, which can be due to changes in the morbidity risk and age specifics, as well as the increase in population.