• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.08a
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• pp.69-72
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• 2002

The conventional thermal insulator and power transformer testing is widely used in surface aging measurement of outside insulator because those testing can carry out very short time in Lab testing. Also thermal testing is able to offer the standard judgement of relative degradation level of outside HV machine. There it is very useful method compare to previous conventional thermal testing method and effective Lab testing method. But surface discharges(SD) have very complex characteristics of discharge pattern so it is required estimation research to development of precise analysis method. In recent, the study of IRR-camera is carrying out discover of temperature of power equipment through condition diagnosis and system development of degradation diagnosis. In this study, thermal testing of power transformer is measured with partial temperature distribution in real time.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.6 no.4
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• pp.54-64
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• 1997

This paper provides a practical control scheme called three-step input method in order to minimize both robot response time and the resulting residual vibration when the robot manipulator reaches its defined end point. This work is concerned with defining a simple practical method to utilize step inputs to achieve optimum response. The optimum response is achieved by using a self- adjusting input command function that is obtained during a real time processing . The practicality of this control scheme is demonstrated by using an analog computer to simulate a simulate a simple flexible robot and conventional servo controller. The experiments focus on point-to-point movement. Also, this method requires little computational effort through the intelligent use of conventional servo control technology and the robot's vibration characteristics.

• Communications for Statistical Applications and Methods
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• v.23 no.6
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• pp.555-562
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• 2016

Interval censored data often occur in an observational study where the subject is followed periodically. Instead of observing an exact failure time, two inspection times that include it are available. There are several methods to analyze interval censored failure time data (Sun, 2006). However, in the presence of competing risks, few methods have been suggested to estimate covariate effect on interval censored competing risk data. A sub-distribution hazard model is a commonly used regression model because it has one-to-one correspondence with a cumulative incidence function. Alternatively, Klein and Andersen (2005) proposed a pseudo-value approach that directly uses the cumulative incidence function. In this paper, we consider an extension of the pseudo-value approach into the interval censored data to estimate regression coefficients. The pseudo-values generated from the estimated cumulative incidence function then become response variables in a generalized estimating equation. Simulation studies show that the suggested method performs well in several situations and an HIV-AIDS cohort study is analyzed as a real data example.

• ETRI Journal
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• v.33 no.4
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• pp.528-536
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• 2011

In this paper, we analyze the location accuracy of real-time locating systems (RTLSs) in multipath environments in which the RTLSs comply with the ISO/IEC 24730-2 international standard. To analyze the location error of RTLS in multipath environments, we consider a direct path and indirect path, in which time and phase are delayed, and also white Gaussian noise is added. The location error depends strongly on both the noise level and phase difference under a low signal-to-noise ratio (SNR) regime, but only on the noise level under a high SNR regime. The phase difference effect can be minimized by matching it to the time delay difference at a ratio of 180 degrees per 1 chip time delay (Tc). At a relatively high SNR of 10 dB, a location error of less than 3 m is expected at any phase and time delay value of an indirect signal. At a low SNR regime, the location error range increases to 8.1 m at a 0.5 Tc, and to 7.3 m at a 1.5 Tc. However, if the correlation energy is accumulated for an 8-bit period, the location error can be reduced to 3.9 m and 2.5 m, respectively.

• Communications for Statistical Applications and Methods
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• v.27 no.2
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• pp.177-187
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• 2020

This article is concerned with the issue of forecasting and evaluation of threshold-asymmetric volatility models for time series of count data. In particular, threshold integer-valued models with conditional Poisson and conditional negative binomial distributions are highlighted. Based on the parametric bootstrap method, some evaluation measures are discussed in terms of one-step ahead forecasting. A parametric bootstrap procedure is explained from which directional measure, magnitude measure and expected cost of misclassification are discussed to evaluate competing models. The cholera data in Bangladesh from 1988 to 2016 is analyzed as a real application.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.4
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• pp.85-93
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• 2015

Liquid rocket engines of KSLV-II employ a turbopump feed system for propellants. A turbopump real-propellant test facility based on liquid oxygen and kerosene has been constructed for the experimental verification of the turbopump performance using the real media of propellants(i.e., LOX/Kerosene). The verification tests of sub-systems were performed such as LOX/kerosene feed system and alcohol burner system. Finally, the performance of the whole system was executed and verified through a sets of validation tests with the development model of the KSLV-II turbopumps. It has been confirmed that the test facility satisfies the operating conditions and time of the turbopump at the design and off-design performance test using real-propellant.

• The KIPS Transactions:PartB
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• v.15B no.6
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• pp.585-594
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• 2008

The issues that we should consider in the process of providing mobile web service using a mobile device are seamless service and QoS-guaranteed service. HMIPv6 has MAP because of improving packet loss and transmission delay due to disconnection. However, a load is concentrated on HMIPv6 because of receiving and delivering packet for MN. Owing to this, real time data fails to be processed quickly, and also adaptive mobile service is required for QoS guaranteed service. However, this method demands the response time cost of contents service owing to the hardware differences of various devices. Therefore, we improve the process performance of real time data by applying a queue in MAP for seamless service in this paper. For decreasing response time cost, we propose mobile web service method which has reusable cache of contents using the elements of contents. The result of a numerical formula and simulation shows that our proposed method is superior under various system conditions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1184-1192
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• 2008

There have been a large number of trials of the experimental education in engineering using virtual laboratories implemented in virtual space, namely on the Web. Although virtual education is regarded as an effective educational means that overcomes the limit of time and space and bring high teaming effects, the problem of lack of reality must be solved. The present study proposed and implemented a real-time remote laboratory as a solution for the problem of lack of reality in virtual education. The remote laboratory provides functions with which learners can perform experiments by remote-controlling circuits and equipment related to experiments and practices on the Web and gets data and image information, so through it learners can make realistic experiments at any time and in any place. The remote laboratory module based on Internet open sources such as JAVA Web start technology, FTP technology and Telnet technology in server-client environment can be implemented at low cost, and is effectively applicable to engineering experiment education in various areas related to real-time hardware control.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.116-120
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• 2008

Smart Camera provides intelligent vision functionalities which can interpret captured video, extract context-aware information and execute a necessary action in real-timeliness in addition to the functionality of network cameras which transmit the compressed acquired videos through networks. Intelligent vision algorithms demand tremendous computations so that real-time processing of computation of intelligent vision algorithms as well as compression and transmission of videos simultaneously is too much burden for a single CPU. Davinci processor of Texas Instruments is a popular ASSP(Application Specific Standard Product) which has dual core architecture of ARM core and DSP core and provides various I/O interfaces as well as networking interface and video acquiring interface necessary for developing digital video embedded applications. In this paper, we report the results of designing and implementing S/W for Davinci-based smart camera. We implement a face detection as an example of vision application and verify the implementation works well. In the future, for the development of a smart camera with more broad and real-time vision functionalities, it is necessary to study about more efficient vision application S/W architecture and optimization of vision algorithms on DSP core of Davichi processor.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.9
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• pp.261-268
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• 2016

One of the most comfortable transportation in our day to day life is the bus, which provides real time information. In order to obtain reliable information on the arrival time of this information, BIS (Bus Information System) needs to analyse the main factor for the traffic environment. To manage the system, regional information analysis by local municipalities should be prioritized. In this paper, we analyse the features that are expected to affect traffic environment by commuting the travel to school, market, tourism and other influences around Suncheon-si, which has the facilities for education, tourism and urban locality. Data cleaning is performed on the DB information that is being collected from characterization BIS, which is organized by day of the week, day and month, to analyse the key factors of the traffic flow. If this is utilized by applying a key factor to the real time information, it is expected to provide more reliable and accurate information.