• Computers and Concrete
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• 제17권6호
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• pp.761-786
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• 2016

This paper proposes an automated procedure for optimum seismic design of reinforced concrete (RC) frame structures. This procedure combines a smart pre-processing using a Tree Classification Method (TCM) and a nonlinear optimization technique. First, the TCM automatically creates sections database and assigns sections to structural members. Subsequently, a real valued model of Particle Swarm Optimization (PSO) algorithm is employed in solving the optimization problem. Numerical examples on design optimization of three low- to high-rise RC frame structures under earthquake loads are presented with and without considering strong column-weak beam (SCWB) constraint. Results demonstrate the effectiveness of the TCMin seismic design optimization of the structures.

• 제어로봇시스템학회논문지
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• 제15권11호
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• pp.1122-1129
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• 2009

Recently taping robot with smart recognition function have been studied in the coil manufacturing field. Due to the difficulty of 3D surface processing from the complicated working environment, it is not easy to accomplish smart tape attachment motion with non-contact sensor. To solve these problems the applicable surface recognition algorithm and a flexible sensing device has been recommended. In this research, the fusion method between 1D displacement and 3D laser scanner is applied for robust tape attachment about cold rolled coil. With these sensors we develop a two-step exploration and the smart algorithm for the awareness of non-aligned coil's information. In the proposed robot system for tape attachment, the problem is reduced to coil's radius searching with laser displacement sensor at first, and then position and orientation detection with 3D laser scanner. To get the movement at the robot's base frame, the hand-eye compensation between robot's end effector and sensing device should be also carried out respectively. In this paper, we examine the auto-coordinate transformation method in the calibration step for the real environment usage. From the experimental results, it was shown that the taping motion of robot had a robust under the non-aligned cold rolled coil.

• 토지주택연구
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• 제10권1호
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• pp.19-23
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• 2019

In recent years, many studies have been conducted on smart low carbon cities through the fusion of ICT information technology for the purpose of reducing carbon. In this study, we investigated 13 cities in three continents that implement low-carbon city policies and analyzed the size, economic and social characteristics of each city to identify the degree of dynamic mechanism for carbon reduction. To this end, we quantified the elements of the city and analyzed the basic requirements for low-carbon cities using the TOPSIS method. The study found that most cities were better able to activate institutions and cultural conditions, facilities and functional conditions, and economic and industrial conditions than other engines, and these three were the main forms of power for smart low carbon cities. The results of this study are expected to be used as a basis for suggesting policy recommendations and improvement measures for future smart low carbon cities.

• 한국전자파학회논문지
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• 제15권1호
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• pp.1-11
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• 2004

본 논문에서는 변복조(modulation/demodulation) 기능을 수행하는 스마트 안테나 기지국용 채널카드(channel card)를 실제 하드웨어로 구현하였다. 구현된 채널카드(channel card)는 우선적으로 각 구성 모듈의 기능 및 성능을 확인하였고, 완성된 채널카드를 스마트 안테나 시스템에 장착해 실제 필드 시험을 수행하여 성능을 확인하였다. 본 논문에서는 다중경로 페이딩이 존재하는 CDMA2000 1X 환경에서 채널카드의 성능을 필드 실험을 통해서 분석한 결과, DOA(Direction Of Arrival) 방향으로 정확한 빔패턴이 형성되는 것을 확인하였고, 채널카드가 내장된 스마트 안테나 시스템이 기존의 2안테나 다이버시티 시스템보다 FER(Frame Error Rate)이 5∼8배정도 우수하다는 것을 확인하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권3호
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• pp.1040-1057
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• 2014

In this paper, a new bit rate estimation scheme is proposed to determine the bit rate for each subclass in an MPEG-2 TS to H.264/AVC transcoder after dividing an input MPEG-2 TS sequence into several subclasses. Video format transcoding in conventional IPTV and Smart TV services is a time-consuming process since the input sequence should be fully transcoded several times with different bit-rates to decide the bit-rate suitable for a service. The proposed scheme can automatically decide the bit-rate for the transcoded video sequence in those services which can be stored on a video streaming server as small as possible without losing any subject quality loss. In the proposed scheme, an input sequence to the transcoder is sub-classified by hierarchical clustering using a parameter value extracted from each frame. The candidate frames of each subclass are used to estimate the bit rate using a statistical analysis and a mathematical model. Experimental results show that the proposed scheme reduces the bit rate by, on an average approximately 52% in low-complexity video and 6% in high-complexity video with negligible degradation in subjective quality.

• 스마트미디어저널
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• 제4권2호
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• pp.26-33
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• 2015

본 논문은 영상에서 효과적으로 보행자를 삭제하는 자동 삭제 시스템을 제안한다. 첫 번째로 Histogram of Oriented Gradient(HOG) / Linear-Support Vector Machine(L-SVM)분류기를 이용하여 보행자를 찾고, 참조영상으로부터 적절한 배경을 습득하여 삭제될 보행자를 대체한다. 배경은 참조영상 내에서 검색하며 변경된 feather blender 연산은 대체 영역의 경계를 자연스럽게 만든다. 기존에 존재하던 대부분의 시스템이 수동인 것에 반해 제안된 시스템은 자동으로 객체를 검출하고 자연스러운 배경을 생성한다. 실험결과 대체된 영역의 PSNR 평균은 19.246으로 측정되었다.

• Smart Structures and Systems
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• 제15권4호
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• pp.963-995
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• 2015

The effectiveness of the various control algorithms for semi-active structural control systems proposed in the literature is highly questionable when dealing with earthquake actions, which never reach a steady state. From this perspective, the paper summarizes the results of an experimental activity aimed to compare the effectiveness of four different semi-active control algorithms on a structural mock up representative of a class of structural systems particularly prone to seismic actions. The controlled structure is a near full scale 2-story steel frame, equipped with two semi-active bracing systems including two magnetorheological dampers designed and manufactured in Europe. A set of earthquake records has been applied at the base of the structure, by utilizing a shaking table facility. Experimental results are compared in terms of displacements, absolute accelerations and energy dissipation capability. A further analysis on the percentage incidence of undesired and/or unpredictable operations corresponding to each algorithm gives an insight on some factors affecting the reliability and, in turn, the real effectiveness of semi-active structural control systems.

• Smart Structures and Systems
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• 제15권6호
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• pp.1543-1567
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• 2015

In this study, a wireless crack sensor is developed for monitoring cracks propagating in two dimensions. This sensor is developed by incorporating a laser-based optical navigation sensor board (ADNS-9500) into a smart wireless platform (Imote2). To measure crack propagation, the Imote2 sends a signal to the ADNS-9500 to collect a sequence of images reflected from the concrete surface. These acquired images can be processed in the ADNS-9500 directly (the navigation mode) or sent to Imote2 for processing (the frame capture mode). The computed crack displacement can then be transmitted wirelessly to a base station. The design and the construction of this sensor are reported herein followed by some calibration tests on one prototype sensor. Test results show that the sensor can provide sub-millimeter accuracy under sinusoidal and step movement. Also, the two modes of operation offer complementary performance as the navigation mode is more accurate in tracking large amplitude and fast crack movement while the frame capture mode is more accurate for small and slow crack movement. These results illustrate the feasibility of developing such a crack sensor as well as point out directions of further research before its actual implementation.

• Smart Structures and Systems
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• 제18권6호
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• pp.1189-1202
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• 2016

This paper describes an application of wavelet analysis for damage detection of a steel frame structure with bolted connections. The wavelet coefficients of the acceleration response for the healthy and loosened connection structure were calculated at each measurement point. The difference of the wavelet coefficients of the response of the healthy and loosened connection structure is selected as an indicator of the damage. At each node of structure the norm of the difference of the wavelet coefficients matrix is then calculated. The point for which the norm has the higher value is a candidate for location of the damage. The above procedure was experimentally verified on a laboratory-scale 2-meter-long steel frame. The structure consists of 11 steel beams forming a four-bay frame, which is subjected to impact loads using a modal hammer. The accelerations are measured at 20 different locations on the frame, including joints and beam elements. Two states of the structure are considered: healthy and damaged one. The damage is introduced by means of loosening two out of three bolts at one of the frame connections. Calculating the norm of the difference of the wavelet coefficients matrix at each node the higher value was found to be at the same location where the bolts were loosened. The presented experiment showed the effectiveness of the wavelet approach to damage detection of frame structures assembled using bolted connections.

• 스마트미디어저널
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• 제9권4호
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• pp.102-108
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• 2020

본 논문에서는 사람의 손동작에 의해 모바일장치상의 전기장센서를 통해 감지되는 동작신호의 실시간 검출 및 프레임 추출 알고리즘을 제안한다. 동작인식에 사용되는 전기장센서는 주변 환경 및 시점에 따라 랜덤잡음 및 센서 표면의 초기 대전상태의 가변적인 특성으로 인해 안정적으로 동작신호를 검출하는데 어려움이 있다. 본 논문에서는 이와 같은 환경에서도 안정적이고 강건하게 동작신호를 감지하여 검출할 수 있는 동적문턱치 방법(dynamic thresholding method)을 제안한다. 동작발생감지여부는 10Hz low-pass 필터와 MA(Motion Average) 필터를 통한 입력신호가 특정 문턱 전압값을 넘을 경우 감지되는데 감지 시점 센서상의 정전하상태가 가변적이므로 주기적으로 offset 값을 계산하여 새로운 문턱치를 동적으로 적용하는 방법이다. 이러한 방법으로 동작신호 감지율을 98% 이상으로 향상 시킬 수 있었다. 또한 일단 동작이 감지되면 정문턱치(positive thresold)와 부문턱치(negative threshold)의 통과시점, 횟수와 평균 동작주기를 고려한 동작신호프레임 알고리즘을 제안하였으며 이의 프레임추출 성공률도 98% 이상의 성능을 보였다. 본 논문에서 제안한 알고리즘으로 추출된 동작신호는 이후 신호정규화를 거쳐 LSTN 심층신경망 인식부를 거쳐 높은 손동작 인식률을 보임으로서 제안된 알고리즘의 우수함을 입증하였다.