Evaluating the performance of asphalt concrete using CT scanning has become an essential area of research due to its potential to revolutionize the way we assess road materials. Traditional methods often require destructive sampling, which can damage infrastructure and offer limited insight into the material's internal structure. In contrast, CT scanning provides a non-destructive, highly detailed analysis of asphalt's internal features, such as air voids, aggregate distribution, and binder coverage, all of which are critical to its durability and performance. Additionally, the ability to create 3D models from CT scans allows for deeper insights into factors like void connectivity and aggregate bonding, which directly affect the lifespan of pavements. By combining CT imaging with advanced data processing techniques, such as deep learning, this research offers more accurate and reliable methods for optimizing asphalt mix designs, ultimately leading to longer-lasting roads, reduced maintenance costs, and more sustainable construction practices.

PURPOSES : This study aimed to perform real-time on-site construction volume management by using Internet of things (IoT) technology consisting of 3D scanning, image acquisition, wireless communication systems, and mobile apps for new and maintenance construction of concrete bridge deck overlays. METHODS : LiDAR was used to scan the overlay before and after construction to check the overlay volume. An enhanced inductively coupled plasma (ICP) method was applied to merge the LiDAR data scanned from multiple locations to reduce noise, and an anisotropic filter was applied for efficient three-dimensional shape modeling of the merged LiDAR data. The construction volume counter of the mobile mixer was directly photographed using an IP camera, and the data were transmitted to a central server via the LTE network. The video images were transmitted to the central server and optical character recognition (OCR) was used to recognize the counter number and store it. The system was built such that the stored information could be checked in real time in the field or at the office. RESULTS : As a result of using LiDAR to check the amount of overlay construction, the error from the planned amount was 0.6%. By photographing the counter of the mobile mixer using an IP camera and identifying the number on the counter using OCR to check the quantity, the results showed that there was a 2% difference from the planned quantity. CONCLUSIONS : Although the method for checking the amount of construction on site using LiDAR remains limited, it has the advantage of storing and managing the geometric information of the site more accurately. Through the IoT-based on-site production management system, we were able to identify the amount of concrete used in real time with relative accuracy.

In light of recent social concerns related to issues such as water supply pipe deterioration leading to problems like leaks and degraded water quality, the significance of maintenance efforts to enhance water source quality and ensure a stable water supply has grown substantially. In this study, scan statistic was applied to analyze water quality complaints and water leakage accidents from 2015 to 2021 to present a reasonable method to identify areas requiring improvement in water management. SaTScan, a spatio-temporal statistical analysis program, and ArcGIS were used for spatial information analysis, and clusters with high relative risk (RR) were determined using the maximum log-likelihood ratio, relative risk, and Monte Carlo hypothesis test for I city, the target area. Specifically, in the case of water quality complaints, the analysis results were compared by distinguishing cases occurring before and after the onset of "red water." The period between 2015 and 2019 revealed that preceding the occurrence of red water, the leak cluster at location L2 posed a significantly higher risk (RR: 2.45) than other regions. As for water quality complaints, cluster C2 exhibited a notably elevated RR (RR: 2.21) and appeared concentrated in areas D and S, respectively. On the other hand, post-red water incidents of water quality complaints were predominantly concentrated in area S. The analysis found that the locations of complaint clusters were similar to those of red water incidents. Of these, cluster C7 exhibited a substantial RR of 4.58, signifying more than a twofold increase compared to pre-incident levels. A kernel density map analysis was performed using GIS to identify priority areas for waterworks management based on the central location of clusters and complaint cluster RR data.

VR은 사용자가 가상 공간에 완전히 몰입하고 상호 작용할 수 있는 가상 세계이다. 본 연구는 스톱모션 애니 메이션을 VR 애니메이션으로 제작할 시 효과적인 객체 표현 방법에 대한 내용을 제시하고자 한다. 실험 결 과 데이터는 VR 스톱모션 애니메이션 및 일반 스톱모션 애니메이션, VR게임 등 다양한 콘텐츠에 적용이 가 능하다. 3D 오프젝트의 변화되는 형태를 앵글별로 3D 스캔한 후 게임엔진에서 다양하게 활용할 수 있도록 데이터화 한 뒤 콘텐츠에 적용하여 구현한다. 기존 스톱모션 애니메이션에서 느낄 수 있는 수작업 느낌을 살리되 디지털적인 이펙트를 추가적으로 이용할 수 있는 장점이 있다. 기존의 스톱 모션 애니메이터들이 접 근하기 힘든 영역을 작업하는데 필요한 세가지 모듈을 구현하여 실험하였다. VR 콘텐츠 제작에서 오브젝트 의 표현과 관련된 분야의 발전에 기여하게 될 것이며 새로운 방향을 제시할 것이다. 향후 연구에서는 각 캐 릭터 관절의 움직임에 따른 3D 스캔 데이터 관련 연구를 수행할 예정이다.

Unloading operation by the unloader is dependent on the experience of the operator in the cabin. If the operator receives information about the unloading situation in the process of lifting the bucket, it is possible to prevent the collision of the bucket with the ship structure. In recent years, numerous measurement systems have become available on the market for three-dimensional surveying of objects, but they are very expensive. This study presents a high quality, low cost 3D laser scanning system designed for object recognition. The developed 3D laser scanning system is built on the base of a 2D laser sensor by the extension with a servo motor and a rotation module. In order to evaluate performance of the developed 3D laser scanning system, the developed system was applied to scan a shape of hatch and cargo holder on a cargo ship. Experimental results showed that to obtain a 3D scanning data for the area around the hatch and cargo holder.

1998년부터 2000년까지 충청남도 보령군 오천면 횡견도 지선의 잠보형 인공어촉, 자연초구 및 비교구 어장에서 해양환경, 상대어획효과, 종조성 조사와 2001년 사이트스캔 소너 등을 이용하여 인공어초 상태를 조사한 결과를 요약하면 다음과 같다. 조사해역에서 잠보형 어초시설구의 저질은 입도분석 결과, 니질성분8.4%, 모래성분 79.6%, 자갈성분이 12%로 사질이 우세하였다. 삼중자망에 의한 잠보형 어초시설구의 비교구에 대한 어획효과는 마리수로는 2.0배, 중량으로는 2.7배의 효과가 있었는데, 최소유의차(LSD)로 검정한 결과, 평균 중량 및 마리수 사이에 5% 유의수준에서 차이가 있는 것으로 나타났다. 통발에 의한 어획시험 결과, 전체 어획량은 적었으나 어초시설구가 비교구 보다 마리수로는 3.2배, 중량으로는 5.0배의 어획 효과가 있었으며, 최소유의차로 검정한 결과, 시설구와 비교구 사이에는 중량에서만 5% 유의수순에서 차이가 있었다. 2000년 10월 어초시설구와 비교구 두곳에서 많이 어획된 도다리의 전장은 어초시설구에서 21.3±2.3cm로 비교구의 22.4±2.1cm보다 작은 것으로 차이가 나타났고(p=0.01), 체중은 어초시설구에서 132.4±42.6g, 비교구에서는 155.0±46.1g으로 사설구의 체중이 적은 것으로 나타났다(p=0.02). 따라서, 시설구는 소형어의 성육장 역학을 하는 것으로 추정된다. 사이트스캔 소너에 의한 인공어초의 영상은 어초가 밀집하여 쌓인 것, 분산하여 시설된 것, 인공어초가 줄 또는 그물에 덮여 훼손된 것, 세굴현상이 일어난 것 및 어초의 일부가 매몰이 된 것을 보여주었다 서해 같이 조류가 빠른 해역에서, 저질이 모래인 경우는 조류에 의해 표사 이동이 일어나므로, 현재의 적지선정 기준에 대해서 지역에 따른 특수성을 고려한 기준이 추가될 필요가 있는 것으로 판단되었다.

This study is aimed to predict the configuration and tension of a towing cable of a side-scan sonar which plays an important role in developing ocean resources. The governing equations of 3-D static equilibrium equations for a flexible cable are derived and solved using a finite difference method. The forces considered in this paper are effective weights, drag forces due to currents and ship moving, and the tension at both ends of the towing cable. The governing equations are non-linear, so an iteration method is applied to solve the equation. A case study is carried out for several different conditions. The result will be useful for predicting the location of a side-scan sonar and to design the towing system.

Side scanning sonar (SSS) provides valuable information for robot navigation. However using the side scanning sonar images in the navigation was not fully studied. In this paper, we use range data, and side scanning sonar images from UnderWater Simulator (UWSim) and propose measurement models in a feature based simultaneous localization and mapping (SLAM) framework. The range data is obtained by echosounder and sidescanning sonar images from side scan sonar module for UWSim. For the feature, we used the A-KAZE feature for the SSS image matching and adjusting the relative robot pose by SSS bundle adjustment (BA) with Ceres solver. We use BA for the loop closure constraint of pose-graph SLAM. We used the Incremental Smoothing and Mapping (iSAM) to optimize the graph. The optimized trajectory was compared against the dead reckoning (DR).

기존의 예인식으로 운용하는 사이드스캔소나의 경우 조사 시 사용자가 원하는 단면 조사에 어려움이 있어 수중구조물 전동 지그가 개발되었지만, 전동지그를 사용한 음파촬영방법의 경우 보트와 소나가 일체 거동하기 때문에 파랑에 의한 보트 롤링현상, 보트운전자의 운용미 숙 등으로 인한 음파영상의 흔들림발생 등 , 작업환경에 따른 여러 가지 문제로 인하여 데이터의 왜곡이 발생하였다. 따라서 본 연구에서는 기존 사이드스캔소나의 수중조사를 위한 장비운용 시 발생하는 영상의 흔들림을 해결하기 위해, 흔들림 보정센서를 부착하고 흔들림 보정 알고리즘 을 개발하여 흔들림보정이 가능하도록 프로그램을 보완하였다. 또한, 소나 데이터 해상도의 향상 정도를 검증하기 위하여, 현장조사를 통해 흔 들림 보정 전‧ 후 음파영상을 수집하고 손상 의심부에 잠수사를 투입하여 실제 손상길이 및 수심을 측정하여 취득한 음파영상 데이터의 분석을 수행하였다. 본 연구는 향후 사이드스캔소나를 활용한 구조물의 수중부 및 하상면 음파영상 촬영기법의 발전에 기여할 것으로 판단된다.

3D Photo Scan is the science of making measurements from photographs, especially for recovering the exact positions of surface points. 3D Photo Scan may employ high-speed imaging and remote sensing in order to detect, measure and record complex 2D and 3D fields. It will be used as basic data on the facility maintenace through BIM based of RC measurements using advanced 3D photo scan.

This study presents a practical approach for imaging concrete pavement and bridge deck slabs for the presence of delamination defects. Air-coupled impact resonance (i.e. impact-echo) test data are presented as a fused image using stacked spectral C-scans of the tested deck surface. The low frequency (less than 6 kHz) dynamic vibrational response of delamination defects, principally caused by the behavior of flexural vibration modes, clearly and accurately reveals the presence of internal shallow delamination defects. Images are constructed with data from air-coupled impact resonance tests carried out on laboratory and field concrete deck samples and an in-service concrete bridge deck.