• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.4
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• pp.707-714
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• 2016

Active driving safety systems for vehicle, such as the front collision avoidance, lane departure warning, and lane change assistance, have been popular to be adopted to the compact car. For improving performance and competitive cost, FMCW radar has been researched to adopt a phased array or a multi-beam antenna, and to integrate the front and the side radar. In this paper we propose several efficient methods to implement the signal processing module of FMCW radar system using low cost DSP. The pulse width modulation (PWM) based analog conversion, the approximation of time-eating functions, and the adoption of vector-based computation, etc, are proposed and implemented. The implemented signal processing board shows the real-time performance of 1.4ms pulse repetition interval (PRI) with 1024pt-FFT. In real road we verify the radar performance under real-time constraints of 10Hz update time.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.17-22
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• 2009

DaVinci processors are popular media processors for implementing embedded multimedia applications. They support dual core architecture: ARM9 core for video I/O handling as well as system management and peripheral handling, and DSP C64+ core for effective digital signal processing. In this paper, we propose our efforts for optimal implementation of object tracking algorithm in DaVinci-based smart camera which is being designed and implemented by our laboratory. The smart camera in this paper is supposed to support object detection, object tracking, object classification and detection of intrusion into surveillance regions and sending the detection event to remote clients using IP protocol. Object tracking algorithm is computationally expensive since it needs to process several procedures such as foreground mask extraction, foreground mask correction, connected component labeling, blob region calculation, object prediction, and etc. which require large amount of computation times. Thus, if it is not implemented optimally in Davinci-based processors, one cannot expect real-time performance of the smart camera.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.6A
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• pp.551-557
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• 2011

We investigate lattice-reduction-aided precoding techniques using Look-Up table (LUT) for multi-user multiple-input multiple-output(MIMO) systems. Lattice-reduction-aided vector perturbation (VP) gives large sum capacity with low encoding complexity. Nevertheless lattice-reduction process based on the LLL-Algorithm still requires high computational complexity since it involves several iterations of size reduction and column vector exchange. In this paper, we apply the LUT-aided lattice reduction on VP and propose a scheme to generate the LUT efficiently. Simulation results show that a proposed scheme has similar orthogonality defect and Bit-Error-Rate(BER) even with lower memory size.

• Tunnel and Underground Space
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• v.9 no.2
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• pp.131-140
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• 1999

Although there have been lots of geological or geotechnical surveys for construction sites, most of data obtained from these surveys have not been reused properly for the future construction work due to the absence of systematic management of data management system. This research, therefore, has focused on the development of DB system, Rockmass Information Management System(RIMS), to save, manage and reuse these abandoned data, specially test data of rock and rockmass with site conditions. RIMS has not only the basic functions of inputting, modifying, and dynamic searching of data but also several data control modules which can manage, input and correct, analyse and report data. Furthermore it saves data such as strata status, laboratory test results, in-site test results, and so on using 3-dimensional data stacking up structure. It is using x, y coordinates to represent horizontal positions and depth to represent vertical position of data. With the development of RIMS, this research has analyzed and classified present conditions of data in RIMS according to region, rock type, etc.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.6
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• pp.27-36
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• 1999

This paper proposes algorithms that design the highly parallel multiple-valued logic circuit of DTG(Directed Tree Graph) to be represented by tree structure relationship between input and output of nodes. The conventional Nakajima's algorithms have some problems so that this paper introduce the concept of mathematical analysis based on tree structure to design optimized locally computable circuit. Using the proposed circuit design algorithms in this paper it is possible to design circuit in that DTG have any node number - not to design by Nakajima's algorithms. Also, making a comparison between the circuit design using Nakajim's algorithms and this paper's, we testify that proposed algorithms in this paper optimizes circuit design all case of DTG. Some examples are shown to demonstrate the usefulness of the circuit design algorithm.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.12
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• pp.149-155
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• 2012

SSD is a storage device of having high-performance controller and cache buffer and consists of many NAND flash memories. Because NAND flash memory does not support in-place update, valid pages are invalidated when update and erase operations are issued in file system and then invalid pages are completely deleted via garbage collection. However, garbage collection performs many erase operations of long latency and then it reduces I/O performance and increases wear leveling in SSD. In this paper, we propose a new method of de-duplicating valid data and recycling invalid data. The method de-duplicates valid data and then recycles invalid data so that it improves de-duplication ratio. Due to reducing number of writes and garbage collection, the method could increase I/O performance and decrease wear leveling in SSD. Experimental result shows that it can reduce maximum 20% number of garbage collections and 9% I/O latency than those of general case.

• Journal of Korean Society of Steel Construction
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• v.23 no.5
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• pp.581-593
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• 2011

The underlying advantages of using thin-walled corrugatedwebs instead of plate girders with stiffeners are the elimination of instability problems associated with buckling of the thin-walled flat plate, and elimination of the need for transverse stiffeners, which alsoresults in economic advantages. This paper focuses on two aspects related to the structural design technique forsinusoidal corrugated web steel beams, and the optimum design of the beams using real-value genetic algorithms. The structural design process and design variables used in this optimization werecomposed with EN 1993-1-5, DASt-R015 standard and Pasternak et al. (2004), and the valid design capacity of shear buckling of the standards were compared. For the optimum structural design, the objective function, presented as the fullweight of the sinusoidal corrugated web beams, and the slenderness, member forces, and maximum deflection of the beam, were considered constraints. Finally, the simple beam under the uniform load was adopted as a numerical example, and the effective probability parameters of the genetic operators were considered to find the global minimum point.

• Journal of Korea Multimedia Society
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• v.7 no.11
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• pp.1505-1514
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• 2004

Sequence matching in time-series databases is an operation that finds the data sequences whose changing patterns are similar to that of a query sequence. Typically, sequence matching hires a multi-dimensional index for its efficient processing. In order to alleviate the dimensionality curse problem of the multi-dimensional index in high-dimensional cases, the previous methods for sequence matching apply the Discrete Fourier Transform(DFT) to data sequences, and take only the first two or three DFT coefficients as organizing attributes of the multi-dimensional index. This paper first points out the problems in such simple methods taking the firs two or three coefficients, and proposes a novel solution to construct the optimal multi -dimensional index. The proposed method analyzes the characteristics of a target database, and identifies the organizing attributes having the best discrimination power based on the analysis. It also determines the optimal number of organizing attributes for efficient sequence matching by using a cost model. To show the effectiveness of the proposed method, we perform a series of experiments. The results show that the Proposed method outperforms the previous ones significantly.

• Journal of Advanced Navigation Technology
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• v.14 no.5
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• pp.767-774
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• 2010

Due to advantages of NAND flash memory such as non-volatility, low access latency, low energy consumption, light weight, small size and shock resistance, it has become a better alternative over traditional magnetic disk drives, and has been widely used. Traditional DBMSs including mobile DBMSs may run on flash memory without any modification by using Flash Translation Layer (FTL), which emulates a random access block device to hide the characteristics of flash memory such as "erase-before-update". However, most existing FTLs are optimized for file systems, not for DBMSs, and traditional DBMSs are not aware of them. Also, traditional DBMSs do not consider the characteristics of flash memory. In this paper, we propose a flash-conscious storage system for DBMSs that utilizes flash memory as a main storage medium, and carefully put the characteristics of flash memory into considerations. The proposed flash-conscious storage system exploits log records to avoid costly update operations. It is shown that the proposed storage system outperforms the state.

• Journal of Korea Multimedia Society
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• v.7 no.1
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• pp.35-43
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• 2004

In this paper, we proposed a vehicle recognition and electronic toll collection system with detection and classification of vehicle identification mark and emblem as well as recognition of vehicle license plate to unman toll fee collection system or incoming/outcoming vehicles to an institution. In the proposed algorithm, we first process pre-processing step such as noise reduction and thinning from the rear side input image of vehicle and detect vehicle mark, emblem and license plate region using intensity variation informations, template masking and labeling operation. And then, we classify the detected vehicle features regions into vehicle mark and emblem as well as recognize characters and numbers of vehicle license plate using hybrid and seven segment pattern vector. To show the efficiency of the proposed algorithm, we tested it on real vehicle images of implemented vehicle recognition system in highway toll gate and found that the proposed method shows good feature detection/classification performance regardless of irregular environment conditions as well as noise, size, and location of vehicles. And also, the proposed algorithm may be utilized for catching criminal vehicles, unmanned toll collection system, and unmanned checking incoming/outcoming vehicles to an institution.