• Title/Summary/Keyword: Building Detection

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A Study on the Characteristics and Utilization of Ash from Sewage Sludge Incinerator (하수(下水)슬러지 소각재의 특성(特性) 평가(評價) 및 재활용(再活用)을 위한 기초연구(基礎硏究))

  • Lee, Hwa-Young
    • Resources Recycling
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    • v.17 no.3
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    • pp.3-9
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    • 2008
  • The measurement of physicochemical properties and chemical composition of SSA(sewage sludge ash) has been carried out and the preparation of lightweight material has also been performed using SSA for reuse as building or construction materials. For this aim, lightweight material has been prepared by forming the mixture of SSA, lightweight filler and inorganic binder followed by calcination at elevated temperature and characterized in terms of density and compressive strength. The pH of fly ash was found to be slightly alkaline, pH 8.69, due to the addition of caustic soda in order to neutralize the acidic gas while the pH of bottom ash was 6.48 Heavy metal leachability based on the standard leach test was also found to be below the detection limit for Cd, Cu, Pb, As and Cr of SSA. As far as the compressive strength of lightweight material was concerned, the compressive strength of lightweight material using fly ash was higher than that of lightweight material using bottom ash.

Energy harvesting techniques for health monitoring and indicators for control of a damaged pipe structure

  • Cahill, Paul;Pakrashi, Vikram;Sun, Peng;Mathewson, Alan;Nagarajaiah, Satish
    • Smart Structures and Systems
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    • v.21 no.3
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    • pp.287-303
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    • 2018
  • Applications of energy harvesting from mechanical vibrations is becoming popular but the full potential of such applications is yet to be explored. This paper addresses this issue by considering an application of energy harvesting for the dual objective of serving as an indicator of structural health monitoring (SHM) and extent of control. Variation of harvested energy from an undamaged baseline is employed for this purpose and the concept is illustrated by implementing it for active vibrations of a pipe structure. Theoretical and experimental analyses are carried out to determine the energy harvesting potential from undamaged and damaged conditions. The use of energy harvesting as indicator for control is subsequently investigated, considering the effect of the introduction of a tuned mass damper (TMD). It is found that energy harvesting can be used for the detection and monitoring of the location and magnitude of damage occurring within a pipe structure. Additionally, the harvested energy acts as an indicator of the extent of reduction of vibration of pipes when a TMD is attached. This paper extends the range of applications of energy harvesting devices for the monitoring of built infrastructure and illustrates the vast potential of energy harvesters as smart sensors.

Design of a GCS System Supporting Vision Control of Quadrotor Drones (쿼드로터드론의 영상기반 자율비행연구를 위한 지상제어시스템 설계)

  • Ahn, Heejune;Hoang, C. Anh;Do, T. Tuan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.10
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    • pp.1247-1255
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    • 2016
  • The safety and autonomous flight function of micro UAV or drones is crucial to its commercial application. The requirement of own building stable drones is still a non-trivial obstacle for researchers that want to focus on the intelligence function, such vision and navigation algorithm. The paper present a GCS using commercial drone and hardware platforms, and open source software. The system follows modular architecture and now composed of the communication, UI, image processing. Especially, lane-keeping algorithm. are designed and verified through testing at a sports stadium. The designed lane-keeping algorithm estimates drone position and heading in the lane using Hough transform for line detection, RANSAC-vanishing point algorithm for selecting the desired lines, and tracking algorithm for stability of lines. The flight of drone is controlled by 'forward', 'stop', 'clock-rotate', and 'counter-clock rotate' commands. The present implemented system can fly straight and mild curve lane at 2-3 m/s.

Analysis of the Disease Spread in a Livestock Building Using Tracer Gas Experiment (추적가스 실험을 통한 축사 내 질병 확산 분석)

  • Song, Sang-Hyeon;Lee, In-Bok;Kwon, Kyeong-Seok;Ha, Tae-Hwan;Bitog, Jessie P.;Hong, Se-Woon;Seo, Il-Hwan;Moon, Oun-Kyeong;Kim, Yeon-Joo;Choi, Eun-Jin
    • Journal of The Korean Society of Agricultural Engineers
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    • v.54 no.3
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    • pp.37-45
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    • 2012
  • Recently, the livestock industry in Korea was heavily affected by the outbreak of official livestock diseases such as foot and mouse disease, high pathogenic avian influenza, swine influenza, and so on. It has been established that these diseases are being spread through direct contact, droplet and airborne transmission. Among these transmissions, airborne transmission is very complex in conducting field investigation due to the invisibility of the pathogens and unstable weather conditions. In this study, the airborne transmission was thoroughly investigated inside a pig house by conducting tracer gas ($CO_2$) experiment because experiment with real pathogen is limited and dangerous. This is possible as it can be assumed that the flow is similar pattern very fine particles and gas. In the experiment, the ventilation structure as well as the location of gas emission were varied. The $CO_2$ detection sensors were installed at 0.5 and 1.3 m height from the floor surface. The tracer gas level was measured every second. Results revealed that the direction of spread can be determined by the response time. Response time refers to the time to reach 150 ppm from the gas emission source at each measuring points. The location of the main flow as well as the gas emission was also found to be very important factor causing the spread.

Linguistic Features Discrimination for Social Issue Risk Classification (사회적 이슈 리스크 유형 분류를 위한 어휘 자질 선별)

  • Oh, Hyo-Jung;Yun, Bo-Hyun;Kim, Chan-Young
    • KIPS Transactions on Software and Data Engineering
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    • v.5 no.11
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    • pp.541-548
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    • 2016
  • The use of social media is already essential as a source of information for listening user's various opinions and monitoring. We define social 'risks' that issues effect negative influences for public opinion in social media. This paper aims to discriminate various linguistic features and reveal their effects for building an automatic classification model of social risks. Expecially we adopt a word embedding technique for representation of linguistic clues in risk sentences. As a preliminary experiment to analyze characteristics of individual features, we revise errors in automatic linguistic analysis. At the result, the most important feature is NE (Named Entity) information and the best condition is when combine basic linguistic features. word embedding, and word clusters within core predicates. Experimental results under the real situation in social bigdata - including linguistic analysis errors - show 92.08% and 85.84% in precision respectively for frequent risk categories set and full test set.

Measurement of Construction Material Quantity through Analyzing Images Acquired by Drone And Data Augmentation (드론 영상 분석과 자료 증가 방법을 통한 건설 자재 수량 측정)

  • Moon, Ji-Hwan;Song, Nu-Lee;Choi, Jae-Gab;Park, Jin-Ho;Kim, Gye-Young
    • KIPS Transactions on Software and Data Engineering
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    • v.9 no.1
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    • pp.33-38
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    • 2020
  • This paper proposes a technique for counting construction materials by analyzing an image acquired by a Drone. The proposed technique use drone log which includes drone and camera information, RCNN for predicting construction material type, dummy area and Photogrammetry for counting the number of construction material. The existing research has large error ranges for predicting construction material detection and material dummy area, because of a lack of training data. To reduce the error ranges and improve prediction stability, this paper increases the training data with a method of data augmentation, but only uses rotated training data for data augmentation to prevent overfitting of the training model. For the quantity calculation, we use a drone log containing drones and camera information such as Yaw and FOV, RCNN model to find the pile of building materials in the image and to predict the type. And we synthesize all the information and apply it to the formula suggested in the paper to calculate the actual quantity of material pile. The superiority of the proposed method is demonstrated through experiments.

Modelling land degradation in the mountainous areas

  • Shrestha, D.P.;Zinck, J.A.;Ranst, E. Van
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.817-819
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    • 2003
  • Land degradation is a crucial issue in mountainous areas and is manifested in a variety of processes. For its assessment, application of existing models is not straightforward. In addition, data availability might be a problem. In this paper, a procedure for land degradation assessment is described, which follows a four-step approach: (1) detection, inventory and mapping of land degradation features, (2) assessing the magnitude of soil loss, (3) study of causal factors, and (4) hazard assessment by applying decision trees. This approach is applied to a case study in the Middle Mountain region of Nepal. The study shows that individual mass movement features such as debris slides and slumps can be easily mapped by photo interpretation techniques. Application of soil loss estimation models helps get insight on the magnitude of soil losses. In the study area soil losses are higher in rainfed crops on sloping terraces (highest soil loss is 32 tons/ha/yr) and minimal under dense forest and in irrigated rice fields (less than 1 ton/ha/yr). However there is high frequency of slope failures in the form of slumps in the rice fields. Debris slides are more common on south-facing slopes under rainfed agriculture or in degraded forest. Field evidences and analysis of causal factors for land degradation helps in building decision trees, the use of which for modelling land degradation has the advantage that attributes can be ranked and tested according to their importance. In addition, decision trees are simple to construct, easy to implement and very flexible in adaptations.

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Indirect Detection of Internal Defects in Wooden Rafter with Ultrasound

  • Lee, Sang-Joon;Lee, Sangdae;Pang, Sung-Jun;Kim, Chul-Ki;Kim, Kwang-Mo;Kim, Ki-Bok;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.41 no.2
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    • pp.164-172
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    • 2013
  • The purpose of this research was development of quantitative ultrasonic test methodology for detecting internal defects in members of ancient wooden building. Connection part between wooden members and/or contacted or hidden part by wall of ceiling or other construction materials make it hard to apply direct way of ultrasonic test. So indirect way of ultrasonic test needed to be applied. Test methodology with newly developed prototype of ultrasonic system was proposed. Homogeneous material with polypropylene was also tested for establishing the criterion. Results showed that TOF(time of flight)-energy and pulse length were found out to be proper ultrasonic parameters for predicting depth of defect in wood different from polypropylene. It was not possible to directly apply prediction equation derived from polypropylene. Newly established prediction equation shows coefficient of determination of 0.73 for wood. Finally, defect of replaced rafter members was predicted with the coefficient of determination of 0.32. Various aspects of ultrasound propagation in wood including anisotropy need to be carefully considered to raise up the prediction accuracy.

Unsupervised Motion Pattern Mining for Crowded Scenes Analysis

  • Wang, Chongjing;Zhao, Xu;Zou, Yi;Liu, Yuncai
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.12
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    • pp.3315-3337
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    • 2012
  • Crowded scenes analysis is a challenging topic in computer vision field. How to detect diverse motion patterns in crowded scenarios from videos is the critical yet hard part of this problem. In this paper, we propose a novel approach to mining motion patterns by utilizing motion information during both long-term period and short interval simultaneously. To capture long-term motions effectively, we introduce Motion History Image (MHI) representation to access to the global perspective about the crowd motion. The combination of MHI and optical flow, which is used to get instant motion information, gives rise to discriminative spatial-temporal motion features. Benefitting from the robustness and efficiency of the novel motion representation, the following motion pattern mining is implemented in a completely unsupervised way. The motion vectors are clustered hierarchically through automatic hierarchical clustering algorithm building on the basis of graphic model. This method overcomes the instability of optical flow in dealing with time continuity in crowded scenes. The results of clustering reveal the situations of motion pattern distribution in current crowded videos. To validate the performance of the proposed approach, we conduct experimental evaluations on some challenging videos including vehicles and pedestrians. The reliable detection results demonstrate the effectiveness of our approach.

Can prosthetic limbs made too quickly cause kidney damage?: a pilot study

  • Petrofsky, Jerrold S.;Browne, Mary;Jamshidi, Mahyar;Libo-on, Anthony;Lee, Haneul
    • Physical Therapy Rehabilitation Science
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    • v.3 no.2
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    • pp.119-124
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    • 2014
  • Objective: The use of chemicals for building prosthetic sockets present the possibility of being hazardous and unsafe due to off-gassing. The purpose of the present study was to investigate if freshly made materials used in prosthetic sockets causes off-gassing that would penetrate the skin and cause damage to the kidneys or blood. Design: Cross-sectional study. Methods: In this research, the off-gassing effects during the initial curing process of styrene monomer, vinyl ester resin, epoxy methacrylate resin, benzene-1, 3-dimethaneamine, trimethylhexanedlamine, and paratertiarybutylphenol were analyzed. Acid detection strips were placed inside newly fabricated mock-prosthetic sockets and left overnight in a closed environment to find out if acid was present in the invisible fumes. The plastic was worn by 9 subjects and urinalysis was made after 48 hours to test for any kidney or blood toxicity of the resins. Results: After wearing the plastic cuff for 48 hours, the ratio of protein to creatinine in the urine was raised to an abnormal level in five out of nine subjects. Four out of the nine subjects showed normal protein to creatinine ratios after wearing the device. The results showed that damage to the kidney occurred from wearing the resins after curing in half of the subjects. Conclusions: It is very important to conduct patient intakes which includes the assessment of renal function. Off-gassing in vented chambers may be needed to protect both prosthetists and patients.