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 the contemporary era, 3D printing technology has become widely utilized across diverse fields, including biomedicine, industrial design, manufacturing, food processing, aerospace, and construction engineering. The inherent advantages of automation, precision, and speed associated with 3D printing have progressively led to its incorporation into road engineering. Asphalt, a temperature-responsive material that softens at high temperatures and solidifies as it cools, presents distinctive challenges and opportunities in this context. For the effective implementation of 3D printing technology in road engineering, 3D printed asphalt (3DPA) must exhibit favorable performance and printability. This requires attributes such as good fluidity, extrudability, and buildability. Furthermore, materials utilizing 3DPA for crack repair should possess high viscosity, elasticity, toughness, superior high-temperature stability, and resistance to low-temperature cracking. These characteristics ultimately contribute to enhancing pavement longevity and ensuring worker safety.

Scanning probe microscopy (SPM) has become an indispensable tool in efforts to develop the next generation of nanoelectronic devices, given its achievable nanometer spatial resolution and highly versatile ability to measure a variety of properties. Recently a new scanning probe microscope was developed to overcome the tip degradation problem of the classic SPM. The main advantage of this new method, called Reverse tip sample (RTS) SPM, is that a single tip can be replaced by a chip containing hundreds to thousands of tips. Generally for use in RTS SPM, pyramid-shaped diamond tips are made by molding on a silicon substrate. Combining RTS SPM with Scanning spreading resistance microscopy (SSRM) using the diamond tip offers the potential to perform 3D profiling of semiconductor materials. However, damage frequently occurs to the completed tips because of the complex manufacturing process. In this work, we design, fabricate, and evaluate an RTS tip chip prototype to simplify the complex manufacturing process, prevent tip damage, and shorten manufacturing time.

As nuclear decommissioning ventures become increasingly complex, the role of digitalization in facilitating and enhancing these operations is becoming indispensable. This transition to a more digitized approach presents a myriad of advantages, including: augmented avenues for data acquisition, analysis, and visualization to bolster dismantling strategies; simulations in virtual environments for operator training; precise forecasting of future waste emergence, culminating in refined cost estimations; and more immersive decommissioning visualizations for both operators and external stakeholders. Salient benefits conferred by the integration of digital technologies in decommissioning encompass improved collaboration, enriched knowledge transfer, clarity regarding present technological constraints, insights into key influencing factors, clearer criteria for technology selection, and a profound understanding of the potential challenges and merits of a broader incorporation of digital tools in decommissioning endeavors. Of paramount importance is the opportunity presented for superior workforce training and safety measures, exemplified by ALARAbased planning. Amidst the myriad facets of digital adoption, 3D modeling of nuclear facilities derived from laser-scanned point clouds stands out as a pivotal domain in the digitalization. The transformation of intricate point cloud data into a comprehensible 3D mesh remains the crux of this paper. The process of mesh generation, despite being simpler than its counterpart of converting to a 3D solid model, is crucial for multiple reasons. The resultant 3D mesh offers an enhanced visual representation compared to a sparse point cloud, paving the way for improved spatial perception. Furthermore, it serves as a rudimentary tool for approximating component volumes and the ensuing waste, thereby playing an instrumental role in waste manipulation strategies, notably in collision detection. This paper delves deep into the nuances of mesh generation, conducting an parametric study of mesh conversion algorithms, including down-sampling rates. Through this rigorous examination, we endeavor to shed light on optimal methodologies, hoping to catalyze advancements in the digitalization of nuclear decommissioning processes.

Engineered Barrier Systems (EBS) are a key element of deep geological repositories (DGR) and play an important role in safely isolating radioactive materials from the ecosystem. In the environment of a DGR, gases can be generated due to several factors, including canister corrosion. If the gas production rate exceeds the diffusion rate, pore pressures may increase, potentially inducing structural deterioration that impairs the function of the buffer material. Therefore, understanding the hydraulic-mechanical behavior of EBS due to gas generation is essential for evaluating the longterm stability of DGR. This study employed X-ray computed tomography (CT) technology to observe cracks created inside the buffer material after laboratory-scale gas injection experiments. After CT scanning, we identified cracks more clearly using an image analysis method based on machine learning techniques, enabling us to examine internal crack patterns caused by gas injection. In the samples observed in this study, no cracks were observed penetrating the entire buffer block, and it was confirmed that most cracks were created through the radial surface of the block. This is similar to the results observed in the LASGIT field experiment in which the paths of the gas migration were observed through the interface between the container and the buffer material. This study confirmed the applicability of high-resolution X-ray CT imaging and image analysis techniques for qualitative analysis of internal crack patterns and cracks generated by gas breakthrough phenomena. This is expected to be used as basic data and crack analysis techniques in future research to understand gas migration in the buffer material.

Background: This study attempted a comparative analysis of three splint fabrication methods currently used in clinical fields. Traditional Orthotic Fabrication Method Utilizing Thermoplastic Resin, the Methodology for creating assistive devices using 3D scanner, commercial CAD software, and 3D printing technology, and the Fabrication Method of Arm Splint Based on XR (eXtended Reality) Algorithm. Objectives: The study recruited 12 undergraduate students majoring in physical therapy and occupational therapy who had sufficient knowledge of splints, with an equal gender distribution. The study randomized the participants and conducted the experiment and overall process using a stratified approach. Design: Clinical applied technology experiment Methods: The study used QUEST 2.0 (Quebec User Evaluation of Satisfaction with assistive Technology ver. 2.0) to survey standardization, weight, ease of use, safety, durability, usability, effectiveness, and patient satisfaction, and statistically analyzed all results as quantitative indicators. Results: The score of QUEST 2.0 showed different aspects in some items, and it is difficult to say that certain technologies are superior overall. Conclusion: The study attempted an intuitive interpretation of the results. Overall, it was concluded that the XR method, which allows for easy and fast fabrication, is likely to be more readily accepted in future clinical practice.

본 논문에서는 인력에 의한 외관 조사의 단점을 해결하고 터널 안전 점검의 자동화를 위하여 터널 스캐닝 영상을 통 한 영상접합 자동화 알고리즘을 제시한다. 터널 스캐닝 영상을 통한 안전 점검은 기존 인력에 의한 외관 조사에 비해 조사 기 간과 인력을 크게 줄일 수 있으며 조사자의 안전사고와 교통체증에 따른 사회적 비용을 절감할 수 있다는 장점이 있다. 터널 스캐닝 영상 기반 안전 점검을 위해서는 터널 스캐닝 영상의 접합을 통하여 평면 전개 이미지 자동화 생성이 핵심이다. 터널 스캐닝 영상 기반 평면 전개 이미지 생성의 자동화를 위하여 특징점 추출 및 특징점 매칭을 통한 다중촬영 이미지 간 접합 과 정이 주요한 요소이다. 본 연구에서는 터널 평면 전개 이미지 자동화 생성의 주요 요소인 이미지 접합의 성능을 높이고 기존 접합 기술에서 발생하는 오류를 해결하기 위하여 특징점 매칭 선분의 물리적인 특성을 고려하여 매칭 정확도를 높인 기술을 제 안하였다. 터널 이미지 중 약80∼90%를 이루는 타일부와 콘크리트부를 대상으로 기존기술의 특징점 매칭 결과와 제안 기술의 특징점 매칭 결과를 비교분석 하였으며 제안 기술을 통해 매칭 성능이 향상된 것을 확인하였다.

카메라 어레이와 사진측량(photogrammetry)을 이용한 3차원 스캐닝 기술은 인체 전신을 게임이나 시각효과 (VFX), 가상인간 등의 다양한 컴퓨터 그래픽스 응용 분야에 활용되고 있다. 특히 최근에는 메타버스 분야에 대한 구축이 활발해 지고 있는 추세여서 실제 인물에 대한 전신 스캔을 보다 저렴하게 수행할 수 있는 시 스템에 대한 요구가 증가하고 있다. 본 연구에서는 고가의 DSLR 카메라를 이용한 시스템보다 1/10정도의 가격으로 구축할 수 있는 시스템을 제작하는 사례를 제시하고자 한다. 인체 전신에 대해 동시촬영의 오차가 적은 시스템을 구축하는데 중점을 두었다. 최근의 컴퓨터 그래픽스 기술은 보다 사실적인 캐릭터를 보다 효 율적으로 생성하고 사용할 수 있는 방법으로 발전하고 있다. 따라서 본 시스템은 최근 다양한 연구와 개발 이 이루어지고 있는 메타버스의 캐릭터 구축이나 게임의 캐릭터의 모델링에 활용할 수 있는 장비로 활용될 수 있을 것으로 기대하며, 이러한 시스템을 좀 더 저비용으로 구축하고자 하는 연구자들이나 개발자들에게 도움이 될 수 있을 것으로 본다. 또한 최신의 실시간 렌더링 시스템의 추세와 삼각측량 관련 연구와 기술의 발전에도 기여할 수 있을 것으로 보인다.

본 논문은 대형 시설물의 점검 및 진단을 위한 외관조사시 영상기반 스캐닝 시스템의 성능 및 정확도를 정량적으로 평가하기 위한 것으로, 도로터널, 철도터널, 지하철과 같은 대형 터널 시설물의 복공 라이닝을 대상으로 영상기반 스캐닝 분석 결과, 균열, 박리, 박락, 철근노출 등 각종 손상의 검출 성능과 정확도를 육안조사, 터널 스캐닝 분석 후 확인조사 데이터를 이용하여 비교 분석하였다. 제안된 터널 스캐닝 시스템의 균열손상 검출성능은 육안조사 분석결과 대비 개소 수 및 면적물량에 있어 월등히 우수함을 확인하였으며, 균열손상 증감을 고려한 균열손상은 현장 확인조사 결과 95%이상의 검출 정확도를 확보하고 있는 것으로 평가되었다.

목적 : 본 연구는 레이저 주사광학계에 응용되는 보급형 f-theta 렌즈의 성능을 향상시키기 위하여 수행되었다. 방법 : ZemaxTM 렌즈설계 프로그램을 이용하여 새로운 f-theta 렌즈 시스템을 설계하였다. 연구 결과는 spot diagram, ray fan, 단색수차 등 3가지 항목에서 선행 연구와 비교·평가되었다. 결과 : 새롭게 설계된 f-theta 렌즈 시스템은 spot size와 레이저 입사광선의 왜곡도가 감소하였으며 특히 구 면수차가 77% 감소하여 대폭 개선되었다. 결론 : 본 연구에서 설계된 f-theta 렌즈 시스템은 전반적으로 상의 질과 성능이 크게 향상되었으며, 레이저 프린터 장비 등에 적용될 수 있으리라 기대된다.