• Smart Media Journal
• /
• v.4 no.2
• /
• pp.26-33
• /
• 2015

In this paper, we propose an efficient automatic pedestrian removal system from a frame in a video sequence. It firstly finds pedestrians from the frame using a Histogram of Oriented Gradient(HOG) / Linear-Support Vector Machine(L-SVM) classifier, searches for proper background patches, and then the patches are used to replace the deleted pedestrians. Background patches are retrieved from the reference video sequence and a modified feather blender algorithm is applied to make boundaries of replaced blocks look naturally. The proposed system, is designed to automatically detect object and generate natural-looking patches, while most existing systems provide search operation in manual. In the experiment, the average PSNR of the replaced blocks is 19.246

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.7C
• /
• pp.663-670
• /
• 2009

In this paper, we propose the image encryption method which gradually uses NFSR(Non-linear Feedback Shift Register) and 20 CAT(Two-Dimensional Cellular Automata Transform). The encryption method is processed in the following order. First, NFSR is used to create a PN(pseudo noise) sequence, which matches the size of the original image. Then, the created sequence goes through a XOR operation with the original image and process the encipherment. Next, the gateway value is set to produce a 20 CAT basis function. The produced basis function is multiplied by encryption image that has been converted to process the 20 CAT encipherment. Lastly, the results of the experiment which are key space analysis, entropy analysis, and sensitivity analysis verify that the proposed method is efficient and very secure.

• Journal of the Korean Society for Precision Engineering
• /
• v.27 no.4
• /
• pp.7-13
• /
• 2010

Linear motors are efficient mechanism that offers high speed and positioning accuracy. By eliminating mechanical transmission mechanisms, much higher speeds and greater acceleration can be achieved without backlash or excessive friction. However, an important disadvantage of linear motor system is its high power loss and heating up of motor and neighboring machine components on operation. Therefore, it is necessary to design moving table with high stiffness, high efficiency and light weight construction. This paper presents the development of moving table using composite material. In order to develop light weight construction of moving table, finite element analysis is performed to find best moving table construction and composite stacking sequence. NASTRAN and MINITAB were used as the optimizer. A prototype for the moving table using composite material was created.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.15 no.5
• /
• pp.873-880
• /
• 2020

The proposed encryption algorithm strengthens its security by converting pixel-specific values and changing pixel positions. The state transition matrix created by Wolfram's rule creates a complemented CA sequence with the maximum length. Then, we convert the sequence into a 2D basis image and go through a XOR operation with the original image. The final encrypted image is created by shear stressing and rearranging. The image stability analysis verified that the proposed encryption method has high security.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38C no.4
• /
• pp.359-364
• /
• 2013

In this paper, we propose a direct sequence ultra wideband (DS-UWB) radar system based on correlation accumulation in the fields of the ship traffic control and the safe ship operation including docking guidance systems. The proposed DS-UWB radar system averages out the noise by accumulating correlator outputs, and thus, provides a reliable distance estimation performance with a shorter estimation time compared with conventional DS-UWB radar systems. From numerical results, it is confirmed that the proposed DS-UWB radar system has not only a shorter average correlation processing time, but also a better distance estimation performance.

• Journal of Power Electronics
• /
• v.16 no.4
• /
• pp.1551-1564
• /
• 2016

The high penetration level of inverter-based distributed generation (DG) power plants is challenging the low-voltage ride-through requirements, especially under unbalanced voltage sags. Recently, a flexible injection of both positive- (PS) and negative-sequence (NS) reactive currents has been suggested for the next generation of grid codes. This can enhance the ancillary services for voltage support at the point of common coupling (PCC). In light of this, considering distant grid faults that occur in a mainly inductive grid, this paper proposes a complete voltage support control scheme for the interface inverters of medium or high-rated DG power plants. The first contribution is the development of a reactive current reference generator combining PS and NS, with a feature to increase the PS voltage and simultaneously decrease the NS voltage, to mitigate voltage imbalance. The second contribution is the design of a voltage support control loop with two flexible PCC voltage set points, which can ensure continuous operation within the limits required in grid codes. In addition, a current saturation strategy is also considered for deep voltage sags to avoid overcurrent protection. Finally, simulation and experimental results are presented to validate the effectiveness of the proposed control scheme.

• IE interfaces
• /
• v.6 no.1
• /
• pp.31-45
• /
• 1993

Setup planning for machining processes is a part of fixture planning which is also a part of process planning. A setup of a part is defined as a group of features which are machined while the part is fixtured in one single fixture. Setup planning includes a number of tasks such as the selection of setup, sequence of setups and datum frame for each setup. Setup planning is an important function in fixture planning which must be able to support and to clamp a workpiece to prevent deflections caused by machining and clamping loads. This paper presents setup planning system using expert system approach(SPES) for prismatic parts which can be machined on vertical milling machine. SPES consists of preprocessing module and main processing module. Preprocessing module executes the conversion of feature data to frame type data and the determination of setups, and main processing module executes the determination of datum frame of each setup and sequance of setups. Preprocessing module is coded by C language and main processing module is a rule-based expert system using EXSYS pro. The performance of SPES is evaluated through case studies and the results show successful work except for operation sequence of machining holes. This is due to the limited rules for machining holes.

• Proceedings of the Korea Contents Association Conference
• /
• 2003.11a
• /
• pp.290-297
• /
• 2003

A time-series database is a set of data sequences, each of which is a list of changing values corresponding to an object. Subsequence matching under time warping is defined as an operation that finds such subsequences whose time warping distance to a given query sequence are below a tolerance from a time-series database. In this paper, we first point out the characteristics of the previous methods for time-series sequence matching under time warping, and then discuss the approaches for applying them to whole matching as well as subsequence matching. Also, we perform quantitative performance evaluation via a series of experiments with real-life data. There have not been such researches in the literature that compare the performances of all the previous methods of subsequence matching under time warping. Thus, our results would be used as a good reference for showing their relative performances.

• Environmental Engineering Research
• /
• v.20 no.4
• /
• pp.370-376
• /
• 2015

This study investigated the effects of various arsenite concentrations on bio-hydrogen production from molasses using a sequence batch reactor (SBR) operated in a series of three batch cycles. In the first batch cycle, hydrogen production was stimulated at arsenite concentrations lower than 2.0 mg/L, while inhibition occurred at arsenite concentration higher than 2.0 mg/L compared to the control. Hydrogen production decreased substantially during the second batch cycle, while no hydrogen was produced during the third batch cycle at all tested concentrations. The toxic density increased with respect to the increase in arsenite concentrations (6.0 > 1.6 > 1.0 > 0.5 mg/L) and operation cycles (third cycle > second cycle > first cycle). The presence of microorganisms such as Clostridium sp. MSTE9, Uncultured Dysgonomonas sp. clone MEC-4, Pseudomonas parafulva FS04, and Uncultured bacterium clone 584CL3e9 resulted in active stimulation of hydrogen production, however, it was unlikely that Enterobacter sp. sed221 was not related to hydrogen production. The tolerance of arsenite in hydrogen producing microorganisms decreased with the increase in induction time, which resulted in severing the inhibition of continuous hydrogen production.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2009.05a
• /
• pp.29-32
• /
• 2009

This study is for development combustion test facility of liquid rocket engine system using hydrogen peroxide/kerosene as propellent. For this new facility, we construct thrust measure system, propellent supply system, control and data acquisition system. To perform 200N liquid rocket engine combustion test, operation scenario and sequence were designed. Result of combustion test propellents were supplied to engine stably and confirm of development combustion test facility very well.