• Journal of the Korea Society of Computer and Information
• /
• v.28 no.4
• /
• pp.1-11
• /
• 2023

In this paper, instead of using recurrent neural network, we compare a classification performance of time series imaging algorithms using convolution neural network. There are traditional algorithms that imaging time series data (e.g. GAF(Gramian Angular Field), MTF(Markov Transition Field), RP(Recurrence Plot)) in TSC(Time Series Classification) community. Furthermore, we compare STFT(Short Time Fourier Transform) algorithm that can acquire spectrogram that visualize feature of voice data. We experiment CNN's performance by adjusting hyper parameters of imaging algorithms. When evaluate with GunPoint dataset in UCR archive, STFT(Short-Time Fourier transform) has higher accuracy than other algorithms. GAF has 98~99% accuracy either, but there is a disadvantage that size of image is massive.

• Journal of the Korean Society of Industry Convergence
• /
• v.3 no.2
• /
• pp.149-154
• /
• 2000

The purpose of this study is to measure the compression temperature in cylinder by using the fine thermocouple. As for using the thermocouple, it's response time delay should be regarded, even if it is a fine one. So, the output of thermocouple needs some compensation. The compensation circuit, which consists of a differential and an adding circuit is used for the compensate the time lag. And the time constant of the compensation circuit is determined the time between the TDC and the maximum point of the thermocouple output. Using this compensation circuit, the compression temperature is investigated of the cylinder in the diesel engine.

• Journal of Institute of Control, Robotics and Systems
• /
• v.4 no.4
• /
• pp.517-524
• /
• 1998

This paper discusses the development of a reactive power controller using digital signal processing. Digital Signal Processing is the technique of using digital devices to Process continuous signals or data, often in real-time. And DSP algorithms are associated with a discrete time interval between input samples. When one designs a digital filter, one can use a Laplace transform to determine the continuous time frequency response. The corresponding discrete time transform is called Z transform and depends upon discrete samples of the input spaced equally in time. The objectives of this paper are to minimize real power losses and improve the power factor of a given system. Also, the implementation of a direct-form non recursive filter on the TMS320C31 has been described. The application of this microprocessor-based controller using DSP on test system reveals its numerous advantages. Performance and features of the controller for the reactive power control are analyzed.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.9 no.1 s.24
• /
• pp.109-116
• /
• 2006

This paper presents a real time distance measuring device using a W-band linear frequency modulated continuous wave(FMCW) radar and TMS320C6701 digital signal processor(DSP). We used FFT operation for measuring distance with the beat signals and the results of FFT could be converted to distance with ease. We presented how to implement a real time miniaturized hardware system including network protocols using a single DSP core. Also how to control the modulation signal of FMCW system to compensate the VCO nonlinearity using the Time Gating control of DSP is presented. We have shown that the proposed system has good performances for measuring distance in real time via outdoor environment experiments.

• Proceedings of the KIEE Conference
• /
• 1998.07b
• /
• pp.506-508
• /
• 1998

In this paper, the optimal digital redesign is studied within the framework of fuzzy systems and dual-rate sampling control theory. An equivalent fast-rate discrete-time state-space model of the continuous-time system is constructed by using fuzzy inference systems. To obtain the optimal feedback gains developed in the continuous-time system, the constructed fuzzy system is converted into a continuous-time system. The developed continuous-time control law is converted into an equivalent slow-rate digital control law using the proposed digital redesign method. The digital redesign technique using a fuzzy model is employed to simulate the inverted pendulum dynamics.

• Journal of the Semiconductor & Display Technology
• /
• v.10 no.2
• /
• pp.49-56
• /
• 2011

In recent years, owing to the development of the image processing technology, the research to build control system using a vision sensor is stimulated. However, the time delay must be considered, because it works of time to get the result of an image processing in the system. It can be seen as an obstacle factor to real-time control. In this paper, using the pattern matching technique, the location of two objects is recognized from one image which was acquired by a camera. And it is implemented to a position control system as feedback data. Also, a possibility was shown to overcome a problem of time delay using PID controller. A number of experiments were done to show the validity of this study.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2009.05b
• /
• pp.163-166
• /
• 2009

All sorts of technique for schedule progress management is being developed recently, These can change and develop the abstractive concept model to a detailed model that describes the visual 3D image about a schedule plan. but, this technique is troublesome, because this requires the handwork by means of connection between 3D-CAD and scheduling Program. In this study, the process of real-time schedule progress control system using the integrated database by 3D-CAD object information system and schedule module is presented. This study present the process of a schedule progress management using UML, and the process of real-time schedule progress management using RFID system. Through this study, we want to realize the rapid generation of estimated schedule information and to simulate and analyze actual schedule information by real-time.

• Geomechanics and Engineering
• /
• v.13 no.1
• /
• pp.161-171
• /
• 2017

The underlying ground state of a railway plays a significant role in maintaining the integrity of the overlying concrete slab and ultimately supporting the train load. While effective nondestructive tests have been used to evaluate the rail track system, they can only be performed during non-operating time due to the stress wave generated by active sources. In this study, finite element numerical simulations are conducted to investigate the feasibility of detecting unfavorable substructure conditions by using a moving train load. First, a train load module is developed by converting the train load into time-variant equivalent forces. The moving forces based on the shape functions are applied at the nodes. A parametric study that takes into account the bonding state and the train class is then performed. All the synthetic signals obtained from numerical simulations are analyzed at the frequency domain using a Fast Fourier transform (FFT) and at the time-frequency domain using a Short-Time Fourier transform (STFT). The presence of a void condition amplifies the acceleration amplitude and the vibration response. This study confirms the feasibility of using a moving train load to systematically evaluate a rail track system.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.25 no.3
• /
• pp.486-494
• /
• 2001

This paper presents a real-time multibody vehicle dynamic analysis method using recursive Kanes formulation and suspension composite joints. To shorten the computation time of simulation, relative coordinate system is used and the equations of motion are derived using recursive Kanes formulation. Typical suspension systems of vehicles such as MacPherson strut suspension system is modeled by suspension composite joints. The joints are derived and utilized to reduce the computation time of simulation without any degradation of kinematical accuracy of the suspension systems. Using the develop program, a multibody vehicle dynamic model is formed and simulations are performed. Accuracy of the simulation results is compared to the real vehicle field test results. It is found that the simulation results using the proposed method are very accurate and real-time simulation is achieved on a computer with single PowerPC 604 processor.

• Journal of Electrical Engineering and Technology
• /
• v.3 no.4
• /
• pp.576-583
• /
• 2008

In this study, we attempt to design a real-time autonomic nervous system(ANS) evaluation system usable during exercise using heart instantaneous frequency(HIF). Although heart rate variability(HRV) is considered to be a representative signal widely used ANS evaluation system, the R-peak detection process must be included to obtain an HRV signal, which involves a high sampling frequency and interpolation process. In particular, it cannot accurately evaluate the ANS using HRV signals during exercise because it is difficult to detect the R-peak of electrocardiogram(ECG) signals with exposure to many noises during exercise. Therefore, in this study, we develop the ground for a system that can analyze an ANS in real-time by using the HIF signal circumventing the problem of the HRV signal during exercise. First, we compare the HRV and HIF signals in order to prove that the HIF signal is more efficient for ANS analysis than HRV signals during exercise. Further, we performed real-time ANS analysis using HIF and confirmed that the exerciser's ANS variation experiences massive surges at points of acceleration and deceleration of the treadmill(similar to HRV).