• Journal of Korean Society of Transportation
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• v.5 no.2
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• pp.97-112
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• 1987

The objective of this study is to construct not only trip production and attraction in Pusan but also to study and examine appropriateness of the model positively. Depending on the estimation models of trip production and attraction of each zone that have been constructed in this study, it has been proved that the formula of multiple regression by the explanation variables like the indices of total employees, total students, floor spaces of residentials and floor spaces of educational and cultural areas within the study areas have very high explanatory capacity and appropriateness. It si considered that a study of method on new division, integration or omission etc. of the existing zones preceeding for reduction of calculation quantity and a study of estimation error have to be done for future study, if these models are used actually.

• The Journal of Korea Robotics Society
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• v.15 no.1
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• pp.70-76
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• 2020

Multi-floor navigation of a mobile robot requires a technology that allows the robot to safely get on and off the elevator. Therefore, in this study, we propose a method of recognizing the elevator from the current position of the robot and estimating the location of the elevator locally so that the robot can safely get on the elevator regardless of the accumulated position error during autonomous navigation. The proposed method uses a deep learning-based image classifier to identify the elevator from the image information obtained from the RGB-D sensor and extract the boundary points between the elevator and the surrounding wall from the point cloud. This enables the robot to estimate the reliable position in real time and boarding direction for general elevators. Various experiments exhibit the effectiveness and accuracy of the proposed method.

• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.543-545
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• 1999

In case of fire in the high-rise buildings, the appropriate and safe evacuation plans for the building residents are very important to minimize the number of casualties. Since the evacuation time usually depends on the floor plans of the buildings, the evacuation plans should be considered while the architectural design is done. Conventionally, the calculation of the evacuation time in the case of fire breakout is based on the approximate mathematical equations which are prone to error. In this study, the simulator model is developed to help the architectural designers to access the more accurate evacuation time and find out the floor plans which offers the most safe evacuation plans for the residents in case of fire.

• Proceedings of the KIEE Conference
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• 2000.11d
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• pp.618-620
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• 2000

In case of fire in the high-rise buildings, the appropriate and safe evacuation plans for the building residents are very important to minimize the number of casualties. Since the evacuation time usually depends on the floor plans of the buildings, the evacuation plans should be considered while the architectural design is done. Conventionally, the calculation of the evacuation time in the case of fire breakout is based on the approximate mathematical equations which are prone to error. In this study, the simulator model is developed to help the architectural designers to access the more accurate evacuation time and find out the floor plans which offers the most safe evacuation plans for the residents in case of fire.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.308-308
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• 2000

In case of fire in the high-rise buildings, the appropriate and safe evacuation plans for the building residents are very important to minimize the number of casualties. Since the evacuation time usually depends on the floor plans of the buildings, the evacuation plans should be considered while the architectural design is done. Conventionally, the calculation of the evacuation time in the case of fire breakout is based on the approximate mathematical equations which are prone to error In this study, the simulator model is developed to help the architectural designers to access the more accurate evacuation time and find out the floor plans which offers the most safe evacuation plans for the residents in case of fire.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.1
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• pp.33-39
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• 2007

LonWorks over IP (LonWorks/IP) virtual device network (VDN) is an integrated form of LonWorks device network and IP data network. LonWorks/IP VDN can offer ubiquitous access to the information on the factory floor and make it possible for the predictive and preventive maintenance on the factory floor. Timely response is inevitable for predictive and preventive maintenance on the factory floor under the real-time distributed control. The network induced uncertain time delay deteriorates the performance and stability of the real-time distributed control system on LonWorks/IP virtual device network. Therefore, in order to guarantee the stability and to improve the performance of the networked distributed control system the time-varying uncertain time delay needs to be compensated for. In this paper, under the real-time distributed control on LonWorks/IP VDN with uncertain time delay, a control scheme based on disturbance observer and ZPETC(Zero Phase Error Tracking Controller) phase lag compensator is proposed and tested through computer simulation. The result of the proposed control is compared with that of internal model controller (IMC) based on Smith predictor and disturbance observer. It is shown that the proposed control scheme is disturbance and noise tolerant and can significantly improve the stability and the tracking performance of the periodic reference. Therefore, the proposed control scheme is well suited for the distributed servo control for predictive maintenance on LonWorks/IP-based virtual device network with time-varying delay.

• Journal of the Optical Society of Korea
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• v.17 no.6
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• pp.525-532
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• 2013

Contrary to the academic interests of other existing studies elsewhere, this study deals with how the alignment algorithms such as sensitivity or Differential Wavefront Sampling (DWS) can be better used under effects from field, compensator positioning and environmental errors unavoidable from the shop-floor alignment work. First, the influences of aforementioned errors to the alignment state estimation was investigated with the algorithms. The environmental error was then found to be the dominant factor influencing the alignment state prediction accuracy. Having understood such relationship between the distorted system wavefront caused by the error sources and the alignment state prediction, we used it for simulated and experimental alignment runs for Infrared Optical System (IROS). The difference between trial alignment runs and experiment was quite close, independent of alignment methods; 6 nm rms for sensitivity method and 13 nm rms for DWS. This demonstrates the practical usefulness and importance of the prior error analysis using the alignment algorithms before the actual alignment runs begin. The error analysis methodology, its application to the actual alignment of IROS and their results are described together with their implications.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1994.10a
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• pp.175-182
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• 1994

As for the safety evaluation of existing large-scale structures, methods for estimation of the structural and dynamic properties are studied. Sequential prediction error method in time domain and improved FRF estimator in frequency domain are comparatively studied. For this purpose, impact tests of 2 bay 3 floor steel frame structure are performed. Results from both methods are found to be consistent to each others, however those from the finite-element analysis are slightly different from experimental results.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.14-15
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• 2008

In this paper, a new iterative decoding of LDPC codes is proposed. The decoding is based on the posteriori probability of each belief propagation (BP) decoding and an additional postprocessing, that is, erasure decoding of LDPC codes. It turned out that the new method consistently improves the decoding performance on various classes of LDPC codes. For example it removes the error floor of Margulis codes effectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.4
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• pp.427-438
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• 1998

The bit error rate(BER) performance of Trellis Coded QPSK signal in the presence of cochannel interference (CCI) and Rician fading is investigated. The trellis coded QPSK system adopts Maximum Ratio Combining (MRC) diversity reception and Reed-Solomon code to enhance system performance. Using the derived error probability equation, the error performance of trellis coded QPSK system has been evaluated and shown in figures to discuss as a function of signal power to noise power ratio (SNR), signal power to interference power ratio(SIR), direct to indirect signal power ratio ($K_R$), the number of diversity branch (M), the frame length of Reed-Solomon code (n), the number of error correction symbol (t), and the number of state of trellis encoder. From the results, we know that proposed system is affected by cochannel interference and fading in microcell environment. Also, BER performance of Trellis Coded QPSK system can be improved as increasing either the power of desired signal or the value of SIR. And the BER floor in microcellular system is caused by the cochannel interference and it occurs at high BER when SIR is low. And Reed-Solomon code (n=15, t=2) is more effective to restrain the affection of CCI and fading than MRC diversity reception (M=2).