• Journal of the Korea Institute of Information Security & Cryptology
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• v.10 no.3
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• pp.29-36
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• 2000

It is very import role to increase communication quality that fast detection of random sequence synchronization fail in synchronous stream cipher system using initial synchronization mode. Generally it sends additional information to detect random sequency synchronization fail. But we can't transmit additional informations to decide synchronization fail in a system using RMVD to correct channel error. In this paper we propose a method to detect synchronization fail in the receiver even though a system using RMVD has no margin to send additional information, For detecting random sequency synchronization fail we decipher receiver data analyze probability of transition rate for pre-determined period and decide synchronization fail using calculated transition rate probability. This proposed method is fast very reliable and robust in noisy channel and is easily implemented with hardware.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.11a
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• pp.155-159
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• 2002

Wire ropes are used in a myriad of various industrial applications such as elevator, mine hoist, construction machinery, lift, and suspension bridge. Especially, wire rope of crane is important component to container transfer. If it happens wire rope failures in operating, it may lead to safety accident, economic power loss by productivity decline, competitive power decline of container terminal and so on. To solve this problem, we developed wire rope fault detecting system as a portable instrument, and this system is consisted of 3 parts that fault detecting part using hall sensor, permanent magnets and analog unit, and digital signal processing part using data acquisition card, monitoring part using wavelet transform, denoising method. In this paper, a wire rope is scanned by this system after makes several broken parts on the surface of wire rope artificially. All detected signal has external noise or disturbance according to circumstances. So, we applied to discrete wavelet transform to extract a signal from noisy data that was used filter. In practical applications of denoising, it is shown that wavelet pursue it with little information loss and smooth signal display. It is verified that the detecting system by denoising has good efficiency for inspecting faults of wire ropes in service. As a result, by developing this system, container terminal could reduce expense because of extension of wire ropes exchange period and could competitive power. Also, this system is possible to apply in several fields like that elevator, lift and so on.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.225-228
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• 2022

The method of calculating the architectural design cost of the Korean Society of Architecture Policy considers the time spent during the design period. Therefore, faster design times can reduce design costs. As a result of a survey of students majoring in architecture, they felt tiredness from repeated floor plan drawings and difficulties in that there were many things to consider when floor plan drawing. In this paper, we implement a program that can automatically convert sketches into standardized floor plans during the architectural design process and a web app for user convenience. In the proposed method, when a user registers a sketch image through a web app, the program separates the space in the drawing through geometric shapes detection. Based on the dimensions and spatial information shown in the sketch, the outer and inner walls are displayed and the appropriate furniture is placed in the space. Through the proposed method, the design cost can be expected to be reduced by reducing the time of the drawing process in the architectural design stage, and 95.2% of architectural students expressed their intention to use the program.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.4
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• pp.83-92
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• 2005

D-OCSP-KIS proposed by Koga and Sakurai not only reduces the number or OCSP Responder's certificate but also criers the certificate status validation about OCSP Responder to the client. Therefore, D-OCSP-KIS is an effective method that can reduce the communication cost, computational time and storage consumption in client, but it has some problems. In case an attacker accidentally acquires an OCSP Responder's session private key in a time period (e.g., one day), she can disguise as the OCSP Responder in the time period unless the OCSP Responder recognizes. She can offer the wrong response to the client using the hash value intercepted. And the server and user on I-commerce can have a serious confusion and damage. And the computation and releasing of hash chain can be a load to CA. Thus, we propose a method detecting immediately the exposure of an OCSP Responder's session private key and the abuse of hash value in D-OCSP-KIS.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.275-278
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• 2003

The pantograph contact can be disrupted due to irregularities in the motion. The pantograph detachment prohibits the current flow and makes the system uncontrollable. During the pantograph detachment period, the control error are accumulated by the integral property of the controller. The output of the controller, therefore, can be induced to be an extremely large value. When the pantograph is reattached, the extremely large output of the controllers causes a very high overshoot (or under-shoot) of the line current and the DC-link voltage. This work proposes a new method for detecting the pantograph bouncing conditions and designs a controller considering such conditions based on the pantograph bouncing detector.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.157-160
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• 2008

A realization for moving object detecting and tracking system in two dimensional plane using stereo line CCDs and lighting source is presented in this paper. Instead of processing camera images directly, two line CCD sensor and input line image is used to measure two dimensional distance by comparing the brightness on line CCDs. The algorithms are used the moving object tracking and coordinate converting method. To ensure the effective detection of moving path, a detection algorithm to evaluate the reliability of each measured distance is developed. The realized system results are that the performance of moving object recognizing shows 5mm resolution and mean error is 1.89%, and enables to track a moving path of object per 100ms period.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.12
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• pp.894-902
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• 1988

In this paper, a method for the design of robust adaptive controller using the heuristic rules of industrial engineers is presented. This scheme works on the basis of heuristic rules and includes a supervisor, a system identifier and a detuner. The supervisor detects onsetting instability based on the analysis of the amplitude and the trend of error signal, also selects running controllers. Upon detecting instability, the controller is switched to a PID algorithm and run recursively until stability is restored. Simultaneously, new input / output data is gathered and the system identifier runs to get critical sensitivity (kc) and critical period(tc). Based on the new values(kc, tc), a GPC controller is redesigned and normal GPC is finally run. The algorithm described in this paper belongs to the supervised adaptive control category with a limited use of heuristic rules. Finally, we show the robust of this scheme by simulated example.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.7
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• pp.878-882
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• 2004

In this paper, we propose a hierarchical hybrid neural network for detecting faults of induction motor. Implementing the classifier based on the input and output data, we apply appropriate transform and classification method at each step. In the proposed method, after obtaining the current of state of motor for each period, we transform it by Principle Component Analysis(PCA) to reduce its dimension. Before the training process, we use the conditional Fuzzy C-means(FCM) for obtaining the initial parameters of neural network for more effective learning procedure. From the various simulations, we find that the proposed method shows better performance to detect and diagnosis of induction motor and compare than other methods.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.1
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• pp.35-41
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• 2014

This paper presents a design method of programmable low pass filter(PLPF) which reduce an estimation error of a zero crossing point(ZCP) for a high speed brushless DC(BLDC) motor drive. BLDC motor sensorless drive is possible by estimation of ZCP. The ZCP estimated by detecting a change of back-EMF polarity has the estimation error because noises exist on the measured back-EMF. Therefore a calculated commutation timing using the ZCP is inaccurate. And the inexact commutation timing leads to ripples of 3-phase current and degradation of drive performance. This paper proposes the design method of the PLPF to overcome these problems. First, a speed calculated a inaccurate period of the ZCP is analyzed in the frequency domain. Then, the PLPF that has varying cut-off frequency according to change of the speed is designed on the frequency analysis result. The proposed method is verified by the experiment.

• Journal of the Institute of Convergence Signal Processing
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• v.14 no.2
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• pp.82-89
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• 2013

A detection method of high precision digital line within image is proposed in this paper. If we set the size of image to $N{\times}N$, in fact it is difficult to use the resulting values that the amount of computation is $O(N^4)$. Multiple algorithms are examined to reduced the amount of computation to $O(N^3)$, while suppressing the degradation of precision. How to detect line from the image processing, after stretching treatment of line segments extracted by Hough transform in the local area of an image is a great way to be able to detect several long or short line at high speed, but this method is slightly less precision in the detection of tilted line segments. In this paper, a line detection method improving the precision detection of tilted line segment is applied to the local area, thereby this method does not reduce the processing speed, while it is high precision method for detecting line segments. The experimental results confirm that the proposed method can detect a high precision line in a shorter period of time, compared with the existing methods.