• Smart Structures and Systems
• /
• 제24권6호
• /
• pp.723-732
• /
• 2019

Globally road transport networks are subjected to continuous levels of stress from increasing loading and environmental effects. As the most popular mean of transport in the UK the condition of this civil infrastructure is a key indicator of economic growth and productivity. Structural Health Monitoring (SHM) systems can provide a valuable insight to the true condition of our aging infrastructure. In particular, monitoring of the displacement of a bridge structure under live loading can provide an accurate descriptor of bridge condition. In the past B-WIM systems have been used to collect traffic data and hence provide an indicator of bridge condition, however the use of such systems can be restricted by bridge type, assess issues and cost limitations. This research provides a non-contact low cost AI based solution for vehicle classification and associated bridge displacement using computer vision methods. Convolutional neural networks (CNNs) have been adapted to develop the QUBYOLO vehicle classification method from recorded traffic images. This vehicle classification was then accurately related to the corresponding bridge response obtained under live loading using non-contact methods. The successful identification of multiple vehicle types during field testing has shown that QUBYOLO is suitable for the fine-grained vehicle classification required to identify applied load to a bridge structure. The process of displacement analysis and vehicle classification for the purposes of load identification which was used in this research adds to the body of knowledge on the monitoring of existing bridge structures, particularly long span bridges, and establishes the significant potential of computer vision and Deep Learning to provide dependable results on the real response of our infrastructure to existing and potential increased loading.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제16권12호
• /
• pp.3904-3922
• /
• 2022

As a research hotspot, pedestrian detection has a wide range of applications in the field of computer vision in recent years. However, current pedestrian detection methods have problems such as insufficient detection accuracy and large models that are not suitable for large-scale deployment. In view of these problems mentioned above, a lightweight pedestrian detection and early warning method using a new model called you only look once (Yolov5) is proposed in this paper, which utilizing advantages of Yolov5s model to achieve accurate and fast pedestrian recognition. In addition, this paper also optimizes the loss function of the batch normalization (BN) layer. After sparsification, pruning and fine-tuning, got a lot of optimization, the size of the model on the edge of the computing power is lower equipment can be deployed. Finally, from the experimental data presented in this paper, under the training of the road pedestrian dataset that we collected and processed independently, the Yolov5s model has certain advantages in terms of precision and other indicators compared with traditional single shot multiBox detector (SSD) model and fast region-convolutional neural network (Fast R-CNN) model. After pruning and lightweight, the size of training model is greatly reduced without a significant reduction in accuracy, and the final precision reaches 87%, while the model size is reduced to 7,723 KB.

• 한국방재학회 논문집
• /
• 제10권2호
• /
• pp.47-53
• /
• 2010

초속경 LMC(Very-Early Strength Latex-Modified Concrete ; VES-LMC)는 작업성, 강도발현 및 장기 내구성 측면에서 콘크리트 타설 후 3시간 이내에 교통개방을 가능하게 할 목적으로 개발되었고, 교량바닥판 긴급보수 공사에 유용하게 사용되고 있다. 그러나 초속경 LMC에서 라텍스의 사용이 콘크리트의 내구성은 향상시키지만 다량의 갇힌 공기를 양산한다는 단점이 있다. 따라서 취약한 공극구조를 개선하기 위해서는 특별한 방법이 필요하며, 본 논문에서는 울트라파인 플라이 애시가 사용되었다. UFFA VES-LMC의 공기량은 재령 1일에 포졸란 반응의 대부분이 발생하여 재령 1일 공기량이 경화전 공기량보다 저하되었다. 또한 재령 28일 공기량은 재령 1일 공기량의 공극구조와 동일하게 나타나, 포졸란 반응에 의해 콘크리트의 전체 공기량이 감소함을 확인하였다. 수산화칼슘의 첨가는 200 ${\mu}m$이하 크기의 연행공기를 현저하게 증가시키고, UFFA를 15%이상 사용하면 간격계수를 200 ${\mu}m$ 이하까지 확보할 수 있어 VES-LMC의 공극구조 개선에 매우 효과적인 것으로 나타났다.

• 한국대기환경학회지
• /
• 제32권2호
• /
• pp.216-232
• /
• 2016

In present, the Seoul City is undergoing traffic congestion problems caused by rapid urbanization and population growth. Thus the City government has reorganized the mass transportation system since 2004 and the subway has become a very important means for public transit. Since the subway system is typically a closed environment, the indoor air quality issues have often raised by the public. Especially since a huge amount of PM (particulate matter) is emitted from ground tunnels passing through the subway train, it is now necessary to assess the characteristics and behaviors of fine PM inside the tunnel. In this study, the concentration patterns of $PM_1$, $PM_{2.5}$, and $PM_{10}$ in the Seoul subway line-2 were analyzed by real-time measurement during winter (Jan 13, 2015) and summer (Aug 7, 2015). The line-2 consisting of 51 stations is the most busy circular line in Seoul having the railway of 60.2 km length. The the one-day average $PM_{10}$ concentrations were $148{\mu}g/m^3$ in winter and $66.3{\mu}g/m^3$ in summer and $PM_{2.5}$ concentrations were $118{\mu}g/m^3$ and $58.5{\mu}g/m^3$, respectively. The $PM_{2.5}/PM_{10}$ ratio in the underground tunnel was lower than the outdoor ratio and also the ratio in summer is higher than in winter. Further the study examined structural types of underground subsections to explain the patterns of elevated PM concentrations in the line-2. The subsections showing high PM concentration have longer track, shorter curvature radius, and farther from the outdoor stations. We also estimated the outdoor PM concentrations near each station by a spatial statistical analysis using the $PM_{10}$ data obtained from the 40 Seoul Monitoring Sites, and further we calculated $PM_{2.5}/PM_{10}$ and $PM_1/PM_{10}$ mass ratios near the outdoor subway stations by using our observed outdoor $PM_1$, $PM_{2.5}$, and $PM_{10}$ data. Finally, we could develop pollution maps for outdoor $PM_1$ and $PM_{2.5}$ near the line-2 by using the kriging method in spatial analysis. This methodology may help to utilize existing $PM_{10}$ database when managing and control fine particle problems in Korea.

• 한국도로학회논문집
• /
• 제13권3호
• /
• pp.131-137
• /
• 2011

근래의 폭발적인 차량의 증가와 지가 상승, 도시부 시가지 내에서의 지상공간의 공급한계, 자연환경 및 경관에 대한 사용자 요구수준의 증대 등 여러 이유로 지하공간 개발의 필요성이 증대되고 있다. 지하공간의 개발은 필연적으로 건설비의 증가로 이어지며 대형 구조물의 설치는 도시 미관을 저해하는 요인으로 작용하기 때문에 최근에 가능하면 도심 구조물의 경우 경량화, 소형화 하려는 경향이 있다. 따라서 본 연구에서는 효율적인 지하공간의 개발을 위해 대구광역시의 도시부 도로에 설치되어 운영 중인 지하차도 구조물을 대상으로 미시적 소프트웨어인 VISSIM 5.20을 이용하여 소형차 전용 지하차도 도입에 따른 지체시간의 변화를 분석하였다. 소형차 전용 지하차도 도입 시 운영 방식의 변화를 반영하기 위해 대형차량을 지하차도를 통해 통행시키지 않고 지하차도 상부 평면교차로를 이용해 통행하도록 하였으며, 교통특성에 따른 영향을 분석하기 위해 접근로의 포화도(v/c)와 대형차량 혼입률을 순차적으로 증가시켜 통행시간의 변화를 알아보고 기존 지하차도와 비교 분석하였다. 본 연구의 결과로 미루어 볼 때 소형차 전용 지하차도의 도입은 토지매입에 따른 경제적 손실, 구조물의 대형화에 따른 환경훼손 및 친환경적 녹색교통 측면에서도 유리할 것으로 판단된다.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2000년도 봄 학술발표회 논문집
• /
• pp.449-456
• /
• 2000

Remediation grouting has been widely used for the rehabilitation of various civil works like hydraulic and traffic structures. Recently there were some cases of remediation grouting for repairing old dams in korea. So this study will describe the case of remediation grouting of the concrete dam base located east-northern part of Seoul. We use Lugeon Test and Borehole Image Processing System(BIPS) for estimating the effectiveness of remediation grouting of this project. As the results of this study, we could find the lots of joints between the old concrete body and the weathered rock base. So the about 30% quantity of total cement grouts was injected at the boundary surface between concrete and rock base. And Lugeon Test and BIPS could be compared relatively because BIPS results could be presented quantitatively as well as qualitative analysis. Finally, we could find microfine cement was very effectively injected to the fine fissured concrete body compared with ordinary portland cement, but there was little injectability differences beteween microfine cement and ordinary portland cement at the large cracks or cavities were developed rock base.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 1999년도 가을 학술발표회 논문집
• /
• pp.293-300
• /
• 1999

Soilcrete has been the traditional material for the paving and soft ground improvement techniques. But because the durability is not excellent and the quality is not homogeneous, it has not been used for the various purposes up to date. And because the quality of soilcrete is apt to be changed by the content of water and soil stabilizer, and the kind of soil and soil stabilizer, it is not free of cares. But with the increase of naturally oriented needs for the light traffic road such as pedestrian roads of the garden, golf courses and sidewalks, the cases of soilcrete paving has been increased recently. This study aims at making the reference table of the mix design in accordance with the required design specifications for the soilcrete admixtures by the FGC soil stabilizer by using the statistical experiment method. The treated soil is the clay which are widely spreaded in Korea. As the results of this study we can derive the effective reference mix design table for the clay soil treated by the FGC soil stabilizer in accordance with the compressive strength of 50∼200kg/$\textrm{cm}^2$ soilcrete with respect to the contents of water, soil stabilizer and fine sand.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제7권11호
• /
• pp.2804-2823
• /
• 2013

Wireless sensor network (WSN) is a promising technology for monitoring physical phenomena at fine-grained spatial and temporal resolution. However, the typical approach of sending each sensed measurement out of the network for detailed spatial analysis of transient physical phenomena may not be an efficient or scalable solution. This paper focuses on in-network physical phenomena detection schemes, particularly the distributed computation of the boundary of physical phenomena (i.e. event), to support energy efficient spatial analysis in wireless sensor networks. In-network processing approach reduces the amount of network traffic and thus achieves network scalability and lifetime longevity. This study investigates the recent advances in distributed event detection based on in-network processing and includes a concise comparison of various existing schemes. These boundary detection schemes identify not only those sensor nodes that lie on the boundary of the physical phenomena but also the interior nodes. This constitutes an event geometry which is a basic building block of many spatial queries. In this paper, we introduce the challenges and opportunities for research in the field of in-network distributed event geometry boundary detection as well as illustrate the current status of research in this field. We also present new areas where the event geometry boundary detection can be of significant importance.

• 한국산업정보학회논문지
• /
• 제7권5호
• /
• pp.103-111
• /
• 2002

최근 인터넷에서는 인터넷 방송, 영상회의, VoIP 등 서비스 품질 보장을 요구하는 새로운 멀티미디어 서비스들의 출현으로 서비스 품질 제공은 차세대 인터넷에서 가장 주요한 과제 의 하나다. 하지만 현재의 인터넷은 모든 패킷을 동일하게 전달하는 최선 노력 서비스(Best Effort) 서비스만을 제공하고 있기 때문에 서비스에 따른 패킷의 손실 또는 지연 등의 QoS에 대한 요구 사항을 보장해 주지 못하고 있다. 따라서 인터넷에서 서비스의 QoS를 보장해 주기 위해서는 새로운 서비스 모델을 필요로 한다. 본 연구에서는 IP QoS와 관련하여 네트워크에서 QoS 지원을 위한 고려사항 등을 분석하고, DiffServ 모델에서 QoS를 지원할수 있는 동적노드 설정방법을 제시하고 이의 성능을 분석한다.

• 한국정보통신설비학회:학술대회논문집
• /
• 한국정보통신설비학회 2007년도 학술대회
• /
• pp.64-68
• /
• 2007

Commercial WiBro and 3G HSDPA services are launched last year in order to provide high speed wireless Internet access and multimedia service. Currently mobile communication service providers concentrate on the deployment of indoor mobile network since indoor traffic is remarkably increased. For fine indoor wireless communication, an installation of access point system via Public IP network which is called Femtocell is required. The development of indoor Femtocell system must be considered in the viewpoint of low hardware complexity, cost reduction, interlocking with WiBro/HSDPA network without change of network component and easy element management. In this paper, we review the implementation issue and technology of dual mode AP which provides WiBro and HSDPA signal to the user simultaneously. Especially, we describe on the HSDPA Femtocell standardization status and possible 3 types of HSDPA communication module development design. Furthermore we analyze the merits and demerits of each HSDPA Femtocell design type and propose a system which enables handover between indoor HSDPA Femtocell and outdoor commercial HSDPA mobile network.