• Journal of Mechanical Science and Technology
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• v.19 no.6
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• pp.1243-1252
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• 2005

This paper describes a new digital signal processor (DSP) imbalance measurement system dedicated to real-time vibration analysis on rotating machine. To accomplish real-time analysis, the vibration signals are on-line acquired and processed to analyze the mass imbalance and phase position. This is achieved through the use of FFT and Lissajous diagram. The method followed to analyze the mass imbalance with the chosen hardware and software solutions are described in detail in this paper. Several experimental tests demonstrate the efficiency and accuracy in imbalance analysis performance of the DSP system.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.3
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• pp.12-26
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• 2017

The objective of this study was to develop a runoff analysis system of the Nakdong River watershed using the GRM (Grid-based Rainfall-runoff Model), a physically-based distributed rainfall-runoff model, and to assess the system run time performance according to Microsoft Azure VM (Virtual Machine) settings. Nakdong River watershed was divided into 20 sub-watersheds, and GRM model was constructed for each subwatershed. Runoff analysis of each watershed was calculated in separated CPU process that maintained the upstream and downstream topology. MoLIT (Ministry of Land, Infrastructure and Transport) real-time radar rainfall and dam discharge data were applied to the analysis. Runoff analysis system was run in Azure environment, and simulation results were displayed through web page. Based on this study, the Nakdong River real-time runoff analysis system, which consisted of a real-time data server, calculation node (Azure), and user PC, could be developed. The system performance was more dependent on the CPU than RAM. Disk I/O and calculation bottlenecks could be resolved by distributing disk I/O and calculation processes, respectively, and simulation runtime could thereby be decreased. The study results could be referenced to construct a large watershed runoff analysis system using a distributed model with high resolution spatial and hydrological data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11A
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• pp.1035-1046
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• 2005

This paper analyzes the channel assignment techniques and their performance in the On Board Processing (OBP) satellite communication system. It suggests the new Continuous Rate Assignment (CRA) and Dynamic Rare Assignment (DRA) for improving the efficiency of channel assignment at the OBP switch. Mathematical analysis and simulation are given to evaluate the system performance. Aggregate real-time and non-real-time services are considered as different classes. Higher priority is given to voice and video real-time services to avoid delay variation. Onboard scheduler uses CRA and DRA ways to arrange the capacity allocation dynamically. An improved algorithm is given to make the channel more efficient by doing some evaluation of the switching matrix.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.221-225
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• 1987

In this paper, the performance of Mini MAP architecture in realtime application is analyzed by analytic methods. The approximate equations for token rotation time and waiting time are obtained and using these equations network. performance is evaluated. According to the results obtained, Mini MAP architecture has good realtime performance and can be used to many real time applications.

• Journal of Biomedical Engineering Research
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• v.26 no.2
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• pp.87-93
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• 2005

A new method for real-time estimating left ventricular relaxation time constant (T) from the left ventricular (LV) pressure waveform, based on the isovolumic relaxation model, is proposed. The presented method uses a recursive least squares (RLS) algorithm to accomplish real-time estimation. A new criterion to detect the end-point of the isovolumic relaxation period (IRP) for the estimation of T is also introduced, which is based on the pattern analysis of mean square errors between the original and reconstructed pressure waveforms. We have verified the performance of the new method in over 4,600 beats obtained from 70 patients. The results demonstrate that the proposed method provides more stable and reliable estimation of τ than the conventional 'off-line' methods.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.4
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• pp.21-28
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• 1997

The vehicle handling performances have a close relation with the driver's safety. And the CAT(Computer aided testing) system has been introduced as a powerful tool for improving the handling performances. In this study, a CAT system for effectively measuring and analysing the handling performances is developed based on the windows GUI(Graphic user interface) environment. Especially, in order to derive a lot of significant handling performance parameters from a series of proving ground tests, the CAT system has various functions related to real time measurement, time domain analysis, frequency domain analysis, steady state analysis and so on.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.6_1
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• pp.889-896
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• 2020

We describe a new approach to the analyze the control performance of robotic manipulator based on the monitoring system. The structure of monitoring simulator is consist of seven modes such as control state mode, coordinate mode, input/output mode, program mode, parameters mode, and track mode. The applied control algorithme consists of an time varying feed-forward and feedback controller. The proposed scheme is simple in structure, fast in computation, and suitable for real-time implimemtation. Moreover, this scheme does not require any accurate dynamic modeling and values of parameters. Performance of the proposed monitoring system is illustrated by simulation and experiment for robot manipulator with six degrees of freedom.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.10a
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• pp.201-204
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• 2003

This paper presents the analysis of current limiting performance of superconducting fault current limiter(SCFCL) for real substation. The resistive and inductive type SCFCLs are investigated for 154㎸ substation. The current limiting performance of SCFCL is evaluated with respect to the time constant of SCFCL and impedance of SCFCL.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.11
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• pp.2521-2530
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• 1997

In this paepr, we present a video-on-demand (VOD) system design model that address and integrates a number of inter-related issues. Then with analysis and performance evaluation, we investigate various aspects of disk and buffer managements in the given model. Based on the analysis results, we suggest that a distributed buffering scheme with intermediate buffers may te useful to transform bursty disk accesses into a continuous stream for for glitch-free performance of VOD systems. Also, through simulation, we illustrate that massive multimedia information storage design techniques such as prefetching, clustered striping, and real-time disk scheduling integrated with the distributed buffering mechanism may enhance end-to-end real-time performance of VOD systems under wide-area networks.

• Journal of Positioning, Navigation, and Timing
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• v.11 no.4
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• pp.263-268
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• 2022

Precise Point Positioning-Real Time Kinematic (PPP-RTK) is a high accuracy positioning method that combines RTK and PPP to overcome the limitations on service coverage of RTK and convergence time of PPP. PPP-RTK provides correction data in the form of State Space Representation (SSR), unlike RTK, which provides measurement-based Observation Space Representation (OSR). Due to this, PPP-RTK has an advantage that it can transmit less data than RTK. So, recently, several techniques for PPP-RTK have been proposed. However, in order to utilize PPP-RTK techniques, performance analysis of these in a real environment is essential. In this paper, we implement the local network PPP-RTK and analyze the positioning performance according to the distance within 100 km from the reference station in Korea. As results of experiment, the horizontal and vertical 95% errors of local network PPP-RTK were 6.25 cm and 5.86 cm or less, respectively.