• 대한토목학회논문집
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• 제26권5D호
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• pp.723-730
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• 2006

본 연구는 지하철의 표정속도 향상을 통해 승객의 총통행시간을 절감시키고자 수행하였다. 본 연구가 갖는 기존연구와 차별성은 열차의 신호시스템측면을 고려하여 승객의 통행시간변화를 분석했기 때문에 기존의 운영계획측면에서 임의로 운전시격을 변화시켜 분석한 열차의 승객통행시간 절감효과보다 신뢰성과 현실성을 높일 수 있다. 본 연구의 주요내용은 열차운행의 신호시스템측면에서 기존의 고정폐색방식보다 우수한 이동폐색방식을 적용하여 사례노선의 최소운전시격을 산정(시뮬레이션)한 후, 이를 단독 또는 Skip-stop방식과 혼용하여 승객통행시간 절감효과를 분석 제시하였다. 본 연구의 분석결과, 이동폐색방식은 고정폐색방식보다 총통행시간과 표정속도에서 각각 24.4%, 32.3% 향상 효과가 나타났으며, 이를 Skip-stop방식 중 격역정차방식과 혼용하여 적용할 경우, 총통행시간은38.1~52.5%, 표정속도는 최대 58.1%까지 향상되는 시너지 효과가 나타났다.

• 한국시뮬레이션학회논문지
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• 제6권2호
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• pp.59-69
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• 1997

This paper proposes a simulation method of train control system to increase railroad transportation capacity in the Seoul Subway. Comparing with the conventional fixed block system, a new train operation method of "moving block system" shows a more capability of same railroad. A graphic simulation program is developed for application of moving block system to Seoul subway train control system. The result of the simulation program shows a shorten headway i.e. a more dense operation of trains and a higher efficiency of railroad with the suggested moving block system.

• 전자공학회논문지B
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• 제30B권4호
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• pp.104-115
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• 1993

The motion compensated coding (MCC) technique, which exploits the temporal redundancies in the moving images with the motion estimation technique,is one of the most popular techniques currently used. Recently, a variable block size(VBS) motion estimation scheme has been utilized to improve the performance of the motion compensted coding. This scheme allows large blocks to the used when smaller blocks provide little gain, saving rates for areas containing more complex motion. Hence, a new VBS motion estimation scheme with a hierarchical structure is proposed in this paper, in order to combine the motion vector coding technique efficiently. Topmost level motion vector, which is obtained by the gain/cost motion estimation technique with selective motion prediction method, is always transmitted. Thus, the hierarchical VBS motion estimation scheme can efficiently exploit the redundancies among neighboring motion vectors, providing an efficient motion vector encoding scheme. Also, a restricted search with respect to the topmost level motion vector enables more flexible and efficient motion estimation for the remaining lower level blocks. Computer simulations on the high resolution image sequence show that, the VBS motion estimation scheme provides a performance improvement of 0.6~0.7 dB, in terms of PSNR, compared to the fixed block size motion estimation scheme.

• 대한조선학회논문집
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• 제53권2호
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• pp.135-143
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• 2016

In this study, an embedded system composed of equipment setting, block importing, scenario setting and output reporting is developed in multi-body dynamics program, ADAMS, for conducting dynamic structural analysis of block lifting process. First, equipment used for block lifting process is set in the simulation environment and the shapes and functions of two lifting beams, and six block loaders are provided as the equipment. Second, the modal analysis result of the lifting block is imported from the static structural analysis system, NASTRAN. Third, the lifting scenarios, such as hoisting, waiting, trolley moving, and wire connecting, are set in the system. Finally, output results in the forms of plots, texts and tables, are reported after the dynamic structural analysis. The test examples conducted in a shipyard are applied into the developed system in various condition and scenarios. The loads at the lug points, the stress contours, and the hot spot tables of the developed system are compared with the result of the static analysis system.

• 한국지능시스템학회논문지
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• 제7권5호
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• pp.67-76
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• 1997

In this paper, a theoretical study is presented for the force control of a miniature robotic manipulator which is driven by a pair of piezo-electric bimorph cells. In the theoretical analysis, one finger is modeled as a flexible cantilevers with a force sensor at the tip and the finger is a solid beam. The robotic finger is used to hold the objects with different stiffness such as an iron block and a living insect and a moving objcet. So it is very important to develop an adequate controller for the holding operation of the finger. The main problems in force controlling are overdamping, overshoot and unknown environment(such as the stiffness of object and unknown plant parameters). So, the main target is propose the new fuzzy compensation for unknown environment and incease the system performance. The fuzzy compensation is implemented by using PI-type fuzzy approach to identified unknown environment. And the result of proposed controller was compared with the conventaional PID and optimal controller.

• International Journal of Automotive Technology
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• 제8권3호
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• pp.259-268
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• 2007

A knock detection circuit that is based on the signal of an accelerometer installed on the engine block of a spark ignition automotive engine has a band-pass filter with a certain frequency as a parameter to be calibrated. A new statistical method for the determination of the frequency which is the most suitable for the knock detection in real-time applications is proposed. The method uses both the cylinder pressure and block vibration signals and is divided into two steps. In both steps, a new recursive trigonometric interpolation method that calculates the frequency contents of the signals is applied. The new trigonometric interpolation method developed in this paper improves the performance of the Discrete Fourier Transformation, allowing a flexible choice of the size of the moving window. In the first step, the frequency contents of the cylinder pressure signal are calculated. The knock is detected in the cylinder of the engine cycle for which at least one value of the maximal amplitudes calculated via the trigonometric interpolation method exceeds a threshold value indicating a considerable amount of oscillations in the pressure signal; this cycle is selected as a knocking cycle. In the second step, the frequency analysis is performed on the block vibration signal for the cycles selected in the previous step. The knock detectability, which is an individual cylinder attribute at a certain frequency, is verified via a statistical hypothesis test for testing the equality of two mean values, i.e. mean values of the amplitudes for knocking and non-knocking cycles. Signal-to-noise ratio is associated in this paper with the value of t-statistic. The frequency with the largest signal-to-noise ratio (the value of t-statistic) is chosen for implementation in the engine knock detection circuit.