• Smart Structures and Systems
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• 제25권3호
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• pp.265-277
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• 2020

Recently, the concept of "drive-by" bridge monitoring system using indirect measurements from a passing vehicle to extract key parameters of a bridge has been rapidly developed. As one of the most key parameters of a bridge, the natural frequency has been successfully extracted theoretically and in practice using indirect measurements. The frequency of bridge is generally calculated applying Fast Fourier Transform (FFT) directly. However, it has been demonstrated that with the increase in vehicle velocity, the estimated frequency resolution of FFT will be very low causing a great extracted error. Moreover, because of the low frequency resolution, it is hard to detect the frequency drop caused by any damages or degradation of the bridge structural integrity. This paper will introduce a new technique of bridge frequency extraction based on Hilbert Transform (HT) that is not restricted to frequency resolution and can, therefore, improve identification accuracy. In this paper, deriving from the vehicle response, the closed-form solution associated with bridge frequency removing the effect of vehicle velocity is discussed in the analytical study. Then a numerical Vehicle-Bridge Interaction (VBI) model with a quarter car model is adopted to demonstrate the proposed approach. Finally, factors that affect the proposed approach are studied, including vehicle velocity, signal noise, and road roughness profile.

• 한국ITS학회 논문지
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• 제16권1호
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• pp.147-156
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• 2017

본 논문에서 군집주행 서비스를 위해 단체표준에서 정의한 서비스 요구사항을 근거로 하여 WAVE 통신시스템의 성능을 분석하였다. 통신시스템의 주요 성능 파라미터로 제시되는 패킷 에러율과 지연시간 요구조건은 군집으로 주행하는 차량의 제어와 안전을 보장하기 위해 반드시 만족되어야 한다. 실험 시나리오는 크게 군집으로 주행차량들만 존재하는 경우, 통신 반경 내에 다른 간섭차량들이 존재하는 경우 그리고 통신범위 밖에 히든차량들이 존재하는 경우로 나누어 패킷 에러율과 평균지연시간을 분석하였다. 패킷 에러율과 지연시간은 앞에서 언급한 차량들의 토폴로지와 차량 주행속도 그리고 통신반경을 고려하여 모델링 하였다. 수치적 분석 결과는 패킷의 크기, 패킷 생성 주기 그리고 전송속도에 대해 수행되었다. 결론적으로 각 표준에서 정의한 군집주행 성능요구사항에 대해 WAVE 통신 시스템이 제공할 수 있는 안정적인 패킷 성공률과 지연시간 등에 대한 범위를 제시하였다.

• 디지털산업정보학회논문지
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• 제19권2호
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• pp.47-55
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• 2023

Recently, Sensor technologies are emerging to prevent traffic accidents and support safe driving in complex environments where human perception may be limited. The UWS is a technology that uses an ultrasonic sensor to detect objects at short distances. While it has the advantage of being simple to use, it also has the disadvantage of having a limited detection distance. The LDWS, on the other hand, is a technology that uses front image processing to detect lane departure and ensure the safety of the driving path. However, it may not be sufficient for determining the driving environment around the vehicle. To overcome these limitations, a system that utilizes FMCW radar is being used. The BSD radar system using FMCW continuously emits signals while driving, and the emitted signals bounce off nearby objects and return to the radar. The key technologies involved in designing the BSD radar system are tracking algorithms for detecting the surrounding situation of the vehicle. This paper presents a tracking algorithm for designing a BSD radar system, while explaining the principles of FMCW radar technology and signal types. Additionally, this paper presents the target tracking procedure and target filter to design an accurate tracking system and performance is verified through simulation.

• 문화기술의 융합
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• 제4권1호
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• pp.337-351
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• 2018

본 기술 해설 논문은 5G의 IoT, 증강현실, 클라우드 컴퓨팅, 빅데이터, 미래 자율주행주행차 기술을 다루면서 평창 동계 올림픽의 5G이용, 제주 스마트시티 모델을 제시했다. 그 이유는 5G는 4차 산업의 대동맥이기 때문이다. 5G가 4차 산업 대동맥인 이유는 5G가 4차 산업혁명의 핵심 인프라이기 때문이다. 인공지능(AI), 자율주행차, 가상 증강현실(VR AR), 사물인터넷(IoT) 시대가 본격화되려면 지금보다 데이터를 몇십배 이상 더 빠르고, 안전한 상태로 전송할 수 있어야 가능하다. 예컨대 원거리에 있는 자율주행차에 현재 통신 기술인 LTE로 정지 신호를 보낸다면 100분의 1초가량이 걸린다. 상당히 빨라 보이지만, 시속 100km로 달렸다면 차가 정지 때까지 30cm를 움직이기 때문에 안전을 장담하기 어렵다. 5G는 현재의 LTE보다 약 40배가량 빠른 '초당 20기가비트(Gbps) 이상'이다. 이론적으로 1cm 이내에서 차량을 세울 수 있다. 5G는 반경 1km 이내 사물인터넷(IoT) 기기 100만개를 동시에 연결할 뿐 아니라, 속도 지연이 0.001초 이하다. 세계 최대 스마트폰용 반도체업체 퀄컴의 스티브 몰렌코프 최고경영자(CEO)는 "5G는 미래를 연결할 핵심 요소이자 혁신 기술"이라며 "5G 상용화로 2035년쯤에는 12조달러의 경제 유발 효과와 2200만개의 새 일자리 창출 효과를 기대할 수 있을 것"이라고 말했다.

• 유통과학연구
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• 제13권1호
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• pp.27-33
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• 2015

Purpose - The ICT market in the EU is lagging behind that of the US; however, algorithm and software development within the EU have grown steadily, and they involve focusing on the creative cultural convergence conceptualized as part of Horizon 2020 and connecting neighboring markets in the EE and the Mediterranean region. It is essential to study the requirements to market the EU's creative ICT development in emerging industrial countries after examining its applicability in these countries. Research design, data, and methodology - This study deals with data pertaining to the EU's creative industry and competitive edge. The global cultural expansion of the EU facilitates a new concept involving not only low-cost IT products to enhance local cultural artifacts through R&D and the construction of efficient infrastructure services, but also information exchange with a realistic commercialization of the technology that can be applied for creative cultural localization. In the European industry, research on algorithms has been applied for the benefit of consumers. We investigated how the process is conducted in the EU. Results - Europe needs to adjust its economic structure to the local culture as part of IT distribution convergence. The convergence has been converted into a production algorithm with IT in the form of low-cost production. This is because there is an attempt to improve the quality of transport infrastructure, workforce availability, and the distribution of the distance to the local industries and consumers, using IT algorithms. Integrated into the manufacturing industry, based on the ICT infrastructure and solutions, smart localized regional clusters are formed with the help of grafting. Europe has own strategy to increase the number of hub-and-spoke cities. Europe is now becoming integrated, with an EPC system for regional cooperation rather than national competition in ICT technology. Europe has also been recognized in this study as changing the step-by-step paradigm for global competitiveness through new creative culture industries. Conclusions - As a result, there are several ways of converging with others through EU R&D intensity; therefore, the EU can be seen as successfully increasing marginal value, which is useful in developing a special industrial cluster or local cultural cities that create converged development by connecting people and objects with IT. In fact, when compared to the US, Europe has a strong culture and the car industries have a tendency to overshadow the IT industries with integration of services in IT distribution. Considering the rapid environmental changes, the convergence of IT services is likely to take place in Europe, similar to the pharmaceutical industry and the automotive industry. This requires a focus on human resources and automated systems management. The trend is to move away from low-wage industries, switched to key personnel centers of the local university-industry. EU emphasizes the creation of IT market demand in Europe involving local cultural convergence for marketing as the second step to strengthen the economic hub-and-spoke areas.