• Smart Structures and Systems
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• v.22 no.4
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• pp.383-397
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• 2018

Traditional base isolation systems focus on isolating the seismic response of a structure in the horizontal direction. However, in regions where the vertical earthquake excitation is significant (such as near-fault region), a traditional base-isolated building exhibits a significant vertical vibration. To eliminate this shortcoming, a rocking-isolated system named Telescopic Column (TC) is proposed in this paper. Detailed rocking and isolation mechanism of the TC system is presented. The seismic performance of the TC is compared with the traditional elastomeric bearing (EB) and friction pendulum (FP) base-isolated systems. A 4-storey reinforced concrete moment-resisting frame (RC-MRF) is selected as the reference superstructure. The seismic response of the reference superstructure in terms of column axial forces, base shears, floor accelerations, inter-storey drift ratios (IDR) and collapse margin ratios (CMRs) are evaluated using OpenSees. The results of the nonlinear dynamic analysis subjected to multi-directional earthquake excitations show that the superstructure equipped with the newly proposed TC is more resilient and exhibits a superior response with higher margin of safety against collapse when compared with the same superstructure with the traditional base-isolation (BI) system.

• Journal of Broadcast Engineering
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• v.26 no.2
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• pp.208-220
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• 2021

This paper evaluates the performance of multilayer VVC and SHVC. Multilayer VVC supports a multi-layer coding and many coding technologies have been added and extended compared to SHVC. For this reason, it is necessary to evaluate the multi-layer coding performance of VVC and the coding performance for inter-layer reference prediction. Multilayer VVC provides significant BD-rate improvement of AI 24.4%, RA 29.4%, LDB 29.4%, LDP 32.6% on average when compared to SHVC, so that it is shown that VVC can provide scalability more efficiently. On the other hand, the complexity of the encoding time increases by an average of 14 times and decoding time by an average of 1.8 times, which requires efforts to reduce the complexity.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.753-757
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• 2004

This paper describes a PC-based distributed multi-rate realtime control system using USB protocol, which is developed as a general motion controller. The control system consists of two control programs: one running at 1 kHz sampling rate on a PC with Linux and another running at 10 kHz sampling rate on a remotely located motion control card called RASID (remote axis serial interface device). Two programs communicates through USB at every 1 msec. A USB communication driver is developed to ensured the 1 msec desired communication time. The main program running on the PC generates reference trajectory at 1 kHz and send it to the RASID through USB and RASIDs located near the motors gather the sensor information and execute the low-level control at 10 kHz. The USB-based connectivity reduces the wiring harness and eventually the manufacturing cost of the machine. The multi-rate nature of the developed system improves the control capability. The effect of sampling rate is analyzed and simulated.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.489-492
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• 2005

As a former level of MSC(Multi Spectral Camera) telescope of the KOMPSA T2satellite, the several performance tests of EOS(Electro Optical Subsystem) were performed in the EOS level. By these tests, not only the design requirement of payload can be verified but also the test result can be the important criterion to estimate the performance of payload in the launch and space orbit environment. The EOS Geometric Mapping test is to verify the accuracy of the alignment & assembly on the Subsystem of the MSC by measurement like these; LOS(Line of Sight), LOD(Line of Detector), Band to Band Registration, Optical Distortion and Reference Cube. This paper describes the test results and the analysis for the EOS Geometric Mapping.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.5
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• pp.415-421
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• 2014

This study proposes a model-based predictive control for interleaved multi-phase DC/DC converters. The power values necessary to adjust the output voltage in the succeeding are predicted using a converter model. The output power is controlled by selecting the optimal duty cycle. The proposed method does not require controller loops and modulators for converter switching. This method can control the converter by calculating the optimal duty cycle, which minimizes the error between the reference and actual output voltage. The effectiveness of the proposed method is verified through simulations and experiments.

• Journal of Electrical Engineering and Technology
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• v.12 no.5
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• pp.1980-1990
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• 2017

A study on the multi-objective optimization of Interior Permanent-Magnet Synchronous Motors (IPMSMs) with 2, 3, 4 and 5 flux barriers per magnetic pole, based on Genetic Algorithm (GA) is presented by considering the aspect of irreversible demagnetization. Applying the 2004 Toyota Prius single-layer IPMSM as the reference machine, the asymmetrical two-, three-, four- and five-layer rotor models with the same amount of Permanent-Magnets (PMs) is presented to improve the torque characteristics, i.e., reducing the torque pulsation and increasing the average torque. A reduction of the torque pulsations is achieved by adopting different and asymmetrical flux barrier geometries in each magnetic pole of the rotor topology. The demagnetization performance in the PMs is considered as well as the motor performance; and analyzed by using finite element method (FEM) for verification of the optimal solutions.

• Ocean and Polar Research
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• v.36 no.4
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• pp.465-473
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• 2014

This paper proposes a formation control method by which multi-mining robots maintain a specified formation and follow a path. To secure the path tracking performance, a pure-pursuit algorithm is considered for each individual robot, and to minimize the deviation from the reference path, speed reduction in the steering motion is added. For the formation, in which two robots are parallel in a lateral direction, the robots track the specified path at a constant distance. In this way, the Leader-Follower method is adopted and the following robot knows the position and heading angle of the leader robot. Through the experimental test using two ground vehicle models, the performance is verified.

• Journal of Multimedia Information System
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• v.1 no.1
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• pp.1-10
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• 2014

In this paper, we propose a new view synthesis technique for coding of multi-view color and depth data in arbitrary camera arrangements. We treat each camera position as a 3-D point in world coordinates and build clusters of those vertices. Color and depth data within a cluster are gathered into one camera position using a hierarchical representation based on the concept of layered depth image (LDI). Since one camera can cover only a limited viewing range, we set multiple reference cameras so that multiple LDIs are generated to cover the whole viewing range. Therefore, we can enhance the visual quality of the reconstructed views from multiple LDIs comparing with that from a single LDI. From experimental results, the proposed scheme shows better coding performance under arbitrary camera configurations in terms of PSNR and subjective visual quality.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.125-128
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• 1989

This paper presents a DC servo motor controller using self-tuning PID algorithm, which can support Multi-processor for the real time processing. Computer simulation as well as experiment using Multi-processor(8088) are implemented with self-tuning PID algorithm. Presented algorithm is used to compare the performance of the controller with that of the classical PID controller through computer simulation and experiment. The result which use the Self-Tuning algorithm show that motor output follows the reference input trajectory fairly well inspite of load disturbances and parameter variations.

• Journal of Communications and Networks
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• v.12 no.6
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• pp.529-532
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• 2010

Multi-carrier demultiplexer/demodulator (MCDD) in an on-board processing (OBP) satellite used for digital multimedia services has two typical architectures according to the channel demultiplexing procedure: Multistage multi-carrier demultiplexer (M-MCD) or poly-phase fast Fourier transform (PPF). During the channel demultiplexing, phase and quantization errors influence the performance of MCDD; those errors affect the bit error rate (BER) performance of M-MCD and PPF differently. In this paper, we derive the phase error variances that satisfy the condition that M-MCD and PPF have the same signal to noise ratio according to quantization bits, and then, with these results, analyze the BER performances of M-MCD and PPF. The results provided here may be a useful reference for the selection of M-MCD or PPF in designing the MCDD in an OBP satellite communications system.