• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.3
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• pp.427-438
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• 2022

With the recent growing importance over safety management the need for advanced and technical approaches for on-site safety inspection methods has increased. Railway construction is subject to its own particular set of temporal and spatial challenges due to its unique facilities and equipment. This study aimed to investigate the field characteristics of railway infrastructure and improve the conventional field safety management methods by identifying the most appropriate features of AR technology. Group interviews and surveys were conducted with field safety experts to derive the major problems and inspection needs. Subsequently, various features of AR, such as BIM model projection, and remote conferencing, were investigated to determine their applicability to address safety issues. As a result, four problems in the current safety management process, such as 'lack of time due to the conventional inspection method and inspection of areas that are difficult to access', and three major inspection types, such as 'observance of work procedures, status of installation, adequate dimensional spacing', were identified to be improved when adopting AR based techniques. Furthermore, AR technology utilizing plans to solve safety inspection problems and effectively manage major inspection types were proposed, and a follow up survey was conducted with the same field safety experts to derive the priority of technology development.

• Journal of the Korean Chemical Society
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• v.66 no.2
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• pp.96-106
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• 2022

The purpose of this study is to investigate the effect of science-centered convergence class program using realistic contents such as virtual reality and augmented reality on class satisfaction, scientific attitudes and the perception of the gifted students in middle school. After developing the convergence class program including realistic contents using smart devices, we applied it to the gifted students. We analyzed the class satisfaction, scientific attitude and perception of the gifted students through questionnaires. In addition, a survey was conducted on the pre-teachers to investigate and analyze the class satisfaction, scientific attitude of the science class program to students and the perception of science classes using realistic contents. As a result, both students and pre-teachers were positively aware of class satisfaction by science class program using realistic contents. In particular, it was positive in that the class can induce learning motivation and interest. On the other hand, it was pointed out that the low-quality App and lack of infra for smart devices were disadvantages. In addition, pre-teachers lack confidence and information about class using the realistic contents, but they recognize the need of classes using realistic contents for students and education for pre-teachers. Based on this, it obtained suggestions on the preparation of facilities and equipment in schools for future education, development of contents that can be used for convergence class, development of programs and teaching·learning materials using realistic contents, and education for pre-teachers.

• Journal of the Korea Computer Graphics Society
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• v.28 no.3
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• pp.79-89
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• 2022

With the popularity and the advanced graphics hardware technology of mobile devices, various mobile applications that help children with physical activities have been studied. This paper presents SandUp, a mobile application that guides the play of building sand castles using artificial intelligence and augmented reality(AR) technology. In the process of building the sandcastle, children can interactively explore the target virtual sandcastle through the smartphone display using AR technology. In addition, to help children complete the sandcastle, SandUp informs the sand shape and task required step by step and provides visual and auditory feedback while recognizing progress in real-time using the phone's camera and deep learning classification. We prototyped our SandUp app using Flutter and TensorFlow Lite. To evaluate the usability and effectiveness of the proposed SandUp, we conducted a questionnaire survey on 50 adults and a user study on 20 children aged 4~7 years. The survey results showed that SandUp effectively helps build the sandcastle with proper interactive guidance. Based on the results from the user study on children and feedback from their parents, we also derived usability issues that can be further improved and suggested future research directions.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.30-31
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• 2009

Early detection of schedule delay in field construction activities is vital to project management. It provides the opportunity to initiate remedial actions and increases the chance of controlling such overruns or minimizing their impacts. This entails project managers to design, implement, and maintain a systematic approach for progress monitoring to promptly identify, process and communicate discrepancies between actual and as-planned performances as early as possible. Despite importance, systematic implementation of progress monitoring is challenging: (1) Current progress monitoring is time-consuming as it needs extensive as-planned and as-built data collection; (2) The excessive amount of work required to be performed may cause human-errors and reduce the quality of manually collected data and since only an approximate visual inspection is usually performed, makes the collected data subjective; (3) Existing methods of progress monitoring are also non-systematic and may also create a time-lag between the time progress is reported and the time progress is actually accomplished; (4) Progress reports are visually complex, and do not reflect spatial aspects of construction; and (5) Current reporting methods increase the time required to describe and explain progress in coordination meetings and in turn could delay the decision making process. In summary, with current methods, it may be not be easy to understand the progress situation clearly and quickly. To overcome such inefficiencies, this research focuses on exploring application of unsorted daily progress photograph logs - available on any construction site - as well as IFC-based 4D models for progress monitoring. Our approach is based on computing, from the images themselves, the photographer's locations and orientations, along with a sparse 3D geometric representation of the as-built scene using daily progress photographs and superimposition of the reconstructed scene over the as-planned 4D model. Within such an environment, progress photographs are registered in the virtual as-planned environment, allowing a large unstructured collection of daily construction images to be interactively explored. In addition, sparse reconstructed scenes superimposed over 4D models allow site images to be geo-registered with the as-planned components and consequently, a location-based image processing technique to be implemented and progress data to be extracted automatically. The result of progress comparison study between as-planned and as-built performances can subsequently be visualized in the D4AR - 4D Augmented Reality - environment using a traffic light metaphor. In such an environment, project participants would be able to: 1) use the 4D as-planned model as a baseline for progress monitoring, compare it to daily construction photographs and study workspace logistics; 2) interactively and remotely explore registered construction photographs in a 3D environment; 3) analyze registered images and quantify as-built progress; 4) measure discrepancies between as-planned and as-built performances; and 5) visually represent progress discrepancies through superimposition of 4D as-planned models over progress photographs, make control decisions and effectively communicate those with project participants. We present our preliminary results on two ongoing construction projects and discuss implementation, perceived benefits and future potential enhancement of this new technology in construction, in all fronts of automatic data collection, processing and communication.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1321-1330
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• 2023

This study attempts to address the problem of 3D pose estimation for multiple human objects through a single image generated during the character development process that can be used in augmented reality. In the existing top-down method, all objects in the image are first detected, and then each is reconstructed independently. The problem is that inconsistent results may occur due to overlap or depth order mismatch between the reconstructed objects. The goal of this study is to solve these problems and develop a single network that provides consistent 3D reconstruction of all humans in a scene. Integrating a human body model based on the SMPL parametric system into a top-down framework became an important choice. Through this, two types of collision loss based on distance field and loss that considers depth order were introduced. The first loss prevents overlap between reconstructed people, and the second loss adjusts the depth ordering of people to render occlusion inference and annotated instance segmentation consistently. This method allows depth information to be provided to the network without explicit 3D annotation of the image. Experimental results show that this study's methodology performs better than existing methods on standard 3D pose benchmarks, and the proposed losses enable more consistent reconstruction from natural images.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.1
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• pp.1-9
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• 2024

Bridges, which are construction structures, have increased from 584 to 38,405 since the 1970s. However, as the number of bridges increases, the number of bridges with a service life of more than 30 years increases to 21,737 (71%) by 2030, resulting in fatal accidents due to basic human resource maintenance of facilities. Accordingly, the importance of bridge safety inspection and maintenance measures is increasing, and the need for decision-making support for supervisors who manage multiple bridges is also required. Currently, the safety inspection and maintenance method of bridges is to write down damage, condition, location, and specifications on the exterior survey map by hand or to record them by taking pictures with a camera. However, errors in notation of damage or defects or mistakes by supervisors are possible, typos, etc. may reduce the reliability of the overall safety inspection and diagnosis. To improve this, this study visualizes damage data recorded in the BIM model in an AR environment and proposes a maintenance plan for bridges with a small number of people through maintenance decision-making support for supervisors.

• Journal of Digital Contents Society
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• v.11 no.4
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• pp.597-606
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• 2010

This paper describes a real-time camera tracking framework specifically designed to track a monocular camera in an AR workspace. Typically, the Kalman filter is often employed for the camera tracking. In general, however, tracking performances of conventional methods are seriously affected by unpredictable situations such as ambiguity in feature detection, occlusion of features and rapid camera shake. In this paper, a recursive Bayesian sampling framework which is also known as the particle filter is adopted for the camera pose estimation. In our system, the camera state is estimated on the basis of the Gaussian distribution without employing additional uncertainty model and sample weight computation. In addition, the camera state is directly computed based on new sample particles which are distributed according to the true posterior of system state. In order to verify the proposed system, we conduct several experiments for unstable situations in the desktop AR environments.

• Convergence Security Journal
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• v.18 no.4
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• pp.81-87
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• 2018

Military training is being carried out to win the combats through the quick and accurate response exercise for changeable engagement situations on battle fields. However, practically, it is really difficult to do actual fight training. Even though ROK Army is doing effort for practical training in KCTC(Korea army advanced Combat Training Center) supplying such as MILES equipments but a single platoon is able to use KCTC facilities or MILES equipments only 10 days a year. In order to find solution on this problem many researches suggesting AR or VR technology are still on the way. Nevertheless these are not fully covered the training done in the real field. In this regard, this paper proposes how the AR technology algorithm to apply on small units during field training exercise.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• fall
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• pp.331-334
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• 2021

기존의 택배 배송시스템은 수령인 본인이 아니더라도 주소, 전화번호와 같은 개인정보를 쉽게 확인할 수 있다. 코로나 19로 인해 언택트(Untact) 주문 및 배달, 배송 서비스가 급격히 늘어나면서 택배 배송 관련 사업은 거대한 시장으로 성장하고 있으며 이와 함께 노출된 개인정보가 범죄에 악용될 수 있다는 우려도 증가하고 있다. 더불어 여러 택배 및 배송물이 도착했을 때, 수신자는 택배 상자를 뜯지 않고 배송물의 오도착 여부를 확인하기 어려우며 원하는 물품이 담긴 택배가 정확히 어떤 것인지 알기 힘들다.본 프로젝트에서는 다단계 인증이 가능한 QR code를 활용해 송수신자의 주소, 제품 종류, 명칭 등을 포함한 여러 정보를 배송기사, 수령인 등에 따라 선택적으로 접근한다. 같은 QR code를 스캔하더라도 수령인의 경우 모든 정보를 확인할 수 있고, 배달원은 일부의 정보를 확인할 수 있지만, 권한이 없는 사람은 어떠한 정보도 확인할 수 없다. 기존의 택배 배송시스템처럼 정보를 맨눈으로 인식할 수도 없으므로 개인정보 노출의 한계를 극복할 수 있다. 이때 송장 정보는 텍스트 형태뿐 아니라 주문한 내용물의 종류 및 모양 등을 그대로 구현한 AR(augmented reality) 형태로도 확인할 수 있어 포장된 상태 그대로 배송물의 오도착 여부를 확인하거나 다량의 택배를 보다 효율적으로 구분할 수 있다. 이처럼 같은 QR code로 서로 다른 정보를 제공하는 SQRC(Security/Secure QR code)의 원리를 이용해 정보를 안전하게 보호하는 것에 그치지 않고, 비디오나 이미지와 같은 멀티미디어 서비스를 추가로 제공해 실감 미디어의 적용 범위를 넓힐 수 있다.

• Spatial Information Research
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• v.21 no.4
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• pp.83-89
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• 2013

Recently various contents have been produced using the techniques that require high-performance computing process. A lot of services have been being producted as AR(Augmented Reality) service being combined with mobile information service that a moving user search various information based on one's location with. Mobile information service has a characteristic that it needs to get new information according to the location an user moves to. The characteristic requires a lot of communications when user search information moving to a different location. In order to make up for this drawback, we propose a prefetching technique based on speed and viewing angle in this paper. Existing prefetching techniques retrieve the following location of users considering moving speed and direction of the users. The data showed on the screen in AR is limited by the viewing angle of the mobile device. Due to the problems we discussed above, existing prefetching techniques have a demerit that they retrieve a lot more data than needed actually. We propose more efficient way of retrieving data with AR using the viewing angle of the mobile device. The method we propose reduces retrieval of unnecessary location using the users' speed, direction and viewing angle. This method is more efficient than the existing ways of retrieval because we don't need as many data.