• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.5
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• pp.881-889
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• 2016

The VE evaluation process, in which the value is composed of the cost and the function, should have a characteristic of quantitative analysis based on specific figures rather than qualitative approach. However, most of the VE evaluation performed domestically have a problem of having no systematic process of quantification of the function, even though the cost is estimated and analyzed quantitatively. Moreover, in addition to the tendency of strong practical experience, the VE evaluation has the problem of limited application of practical scientific analysis caused by declining the suggestion of creative opinions by over quantification or over objectification. This paper presents the suggestions for improvement of VE evaluation processes, which satisfies the aspects of simplification and objectification, without hindering the essence of the evaluation in the practical business point of view.

• Journal of Broadcast Engineering
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• v.8 no.3
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• pp.306-316
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• 2003

When a cinema being composed of 24 frames/sec is converted to NTSC video or TV program, several fields we repeated to have 60 fields/sec, which is called the telecine or 3:2 pull-down. Hence, when encoding the telecine NTSC video into MPEG format, if we convert it into the original 24 frames/sec Progressive cinema, then we can save 20% of bits compared to the case of encoding all the 60 fields. In this Paper, we propose an algorithm for performing the inverse telecine by using the properties of the frames. Specifically, the algorithm exploits the fact that there Is much Inconsistency between the even and odd fields in the case of telecine frame, which results in high magnitude at the Nyquist frequency In the vertical direction. The experiment shows that the proposed algorithm performs very well regardless of the quality of video with a very few computations, whereas the conventional motion based method requires much computational complexity and its performance is degraded when the video is of low (eg. VHS) quality.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.1
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• pp.98-110
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• 2015

Recently, a validation research of maneuvering and attitude control logics of a spacecraft under a ground condition is getting increase by using operating simulators with compact and precise components. For that, a cold gas propulsion system is generally used for maneuvering and attitude control of spacecraft ground simulators for its simplicity and a high reliability. In the present study, major design parameters of a cold gas propulsion system are derived to meet mission requirements based on conceptual design results of a simulator. And additionally, commercial components with proper specifications are selected for system assembly.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.2
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• pp.7-17
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• 2015

In this paper, we propose a single antenna SSD(simultaneous single band duplex) system using turbo equalizer. The proposed system communicates simultaneously on single band. That is the proposed system is full-duplex system. The proposed system uses balanced feed network circuit to improve isolation in single antenna structure. Also, the proposed system uses RF(radio frequency) cancellation and digital cancellation to cancel self-interference. Additionally, the proposed system uses turbo equalizer to equalize ISI(inter-symbol interference) by harsh multipath fading and to collect bit errors by residual self-interference signals. By using turbo equalizer, the proposed system guarantees QoS(quality of service). In this paper, we uses Simulink simulation program to analyze performance of the proposed system. The simulation results confirm that proposed system can communicate simultaneously by using balanced feed network, RF cancellation, digital cancellation and turbo equalizer in harsh multipath channel on single band.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.5
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• pp.29-37
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• 2009

This paper describes a vision-based and real-time system for detecting road signs from within a moving vehicle. The proposed system has the standard architecture with adaboost algorithm to detect road signs in real time. And it uses the value of vortical plane in the process of extracting candidate areas in view of fact that there are vertically most of signs on roads. Although being useful for detecting objects in real time, the conventional adaboost algorithm deteriorates the performance of detection rate in complex circumstance by reason of using only integral images as features. To overcome this problem, this paper proposes the method that improves the reliability of candidates as using the value of vertical plane for extracting candidate area and improves the performance of the detection rate as using integral images to which we add the kind of feature prototype. The experiments of this paper show that the detection rate of the proposed method has higher than that of the conventional adaboost algorithm under the real complex circumstance of roads.

• Geotechnical Engineering
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• v.3 no.2
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• pp.17-28
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• 1987

Reliability of the cone penetration test (CPT) for estimating shear strength of marine soils is investigated in this paper. For sands, the uncertainty about the angle of internal friction is analyzed. It includes the spatial variation of the soil and the model error in the equation used for interpretation. The most serious uncertainty encountered was the error in the interpretative models. Different methods of interpretation gave quite different values. Subjective opinion was introduced to combine all the interpretative models in a systematic manner. For clays, the undrained Shear Strength from the CPT results is usually =derived by empirical correlations between cone resistance and untrained shear strength from laboratory tests or field vane tests, expressed in terms of cone factor and function of overburden pressure. The uncertainty of the undrained shear strength is caused by data scatter of the cone factor in the correlation, model error of the cone factor, effect of anisotropy, and spatial variability of cone resistance. Among these uncertainties, the most serious one was the data scatter of the cone factor in the .correlation. Between the laboratory test and the field vane test used for correlation, the field vane test was more reliable.

• Journal of the Korean Geotechnical Society
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• v.19 no.5
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• pp.59-67
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• 2003

In this study, the change in hydraulic conductivity according to the changes in the contact area, aperture, confining pressure and temperature was observed to improve the reliability of the analysis of underground water flow. Also, the mechanical and thermal properties of domestic crystalline rocks in a great depth were obtained. It was found that the averaged intial aperture ranged from 544.33${\mu}{\textrm}{m}$ to 898.62${\mu}{\textrm}{m}$ and it followed a log-normal distribution. The hydraulic conductivity decreased with the increase of normal stress on the fracture surface and the hydraulic conductivity decreased as temperature increased. The change in hydraulic conductivity was strongly correlated with the change in contact area. It was verified by experiments that hydraulic conductivity was inversely proportional to the contact area. The measured mechanical and thermal properties were very close to the existing typical properties of domestic granites.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.3
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• pp.90-97
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• 2007

For a highly reliable fingerprint recognition system, the precise and accurate feature extraction is indispensable. In this paper, We propose a highly efficient crease extraction method, which can improve the accuracy of feature extraction within the fingerprint image. The proposed method applies the 1-dimensional directional slit for each pixel in fingerprint image. And then it calculates the average grey level and variance to determine whether the current pixel composes the crease, and estimates the direction of crease. Once the direction of every pixel in crease candidate area is estimated, it is decomposed into 8 different images depending on their direction. From the 8 directional images, the crease clusters are estimated by utilizing the property of crease area. The proposed method finally extracts the crease from the crease clusters estimated from directional images. In conclusion, the proposed method highly improved the accuracy of overall feature extraction by accurate and precise extraction of the crease from fingerprint image.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.5
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• pp.269-274
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• 2004

In this paper, proposed is the dual-mode algorithm of blind decision feedback equalizer (DFE) for digital terrestrial television signals. According to channel impairments, the proposed dual-mode algorithm for blind DFE operates in decision-directed mode or in blind mode of operation. The error signals being used in tap update of the equalizer are generated in the best mode of operations, so that the confidence of equalizer tap coefficient update is more accurate. As a result, it is possible to track the channel characteristics variations by automatic switching over between two modes of operations. For 8-level vestigial sideband modulated digital television signals, the mean square errors and symbol error rates of the proposed algorithm are compared with those of conventional methods. And the usability of the proposed scheme is assessed by computer simulations under various static and dynamic multipath channel environments.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.11 s.353
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• pp.90-97
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• 2006

In this paper, we present a cost-effective architecture of high-speed soft-decision Viterbi decoder for Multi-band OFDM(MB-OFDM) systems. In the design of modem for MB-OFDM systems, a parallel processing architecture is general]y used for the reliable hardware implementation, because the systems should support a very high-speed data rate of at most 480Mbps. A Viterbi decoder also should be designed by using a parallel processing structure and support a very high-speed data rate. Therefore, we present a optimized hardware architecture for 4-way parallel processing Viterbi decoder in this paper. In order to optimize the hardware of Viterbi decoder, we compare and analyze various ACS architectures and find the optimal one among them with respect to hardware complexity and operating frequency The Viterbi decoder with a optimal hardware architecture is designed and verified by using Verilog HDL, and synthesized into gate-level circuits with TSMC 0.13um library. In the synthesis results, we find that the Viterbi decoder contains about 280K gates and works properly at the speed required in MB-OFDM systems.