• Journal of Internet Computing and Services
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• v.25 no.4
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• pp.23-37
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• 2024

Digital twin is an M&S (Modeling and Simulation) technology designed to solve or optimize problems in the real world by replicating physical objects in the real world as virtual objects in the digital world and predicting phenomena that may occur in the future through simulation. Digital twins have been elaborately designed and utilized based on data collected to achieve specific purposes in large-scale environments such as cities and industrial facilities. In order to apply this digital twin technology to real life and expand it into user-customized service technology, practical but sensitive issues such as personal information protection and personalization of simulations must be resolved. To solve this problem, this paper proposes a federated learning-based accelerated client training method (FACTS) for personalized digital twins. The basic approach is to use a cluster-driven federated learning training procedure to protect personal information while simultaneously selecting a training model similar to the user and training it adaptively. As a result of experiments under various statistically heterogeneous conditions, FACTS was found to be superior to the existing FL method in terms of training speed and resource efficiency.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2A
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• pp.81-92
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• 2010

In design of steel frames, it is generally believed that elastic system buckling analysis cannot predict real behaviors of structures, while inelastic system buckling analysis can give informative buckling behaviors of individual members considering inelastic material behavior. However, the use of Euler buckling equation with these system buckling analyses have the inherent problem that the methods evaluate unexpectedly large effective lengths of members having relatively small axial forces. This paper proposes a new method of obtaining elastic and inelastic effective lengths of all members in steel frames. Considering a fictitious axial force factor for each story of frames, the proposed method determines the effective lengths using the inelastic stiffness reduction factor and the iterative eigenvalue analysis. In order to verify the validity of the proposed method, the effective lengths of example frames by the proposed method were compared to those of previously established methods. As a result, the proposed method gives reasonable effective lengths of all members in steel frames. The effect of inelastic material behavior on the effective lengths of members was also discussed.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.6
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• pp.897-906
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• 2017

Projection Mapping, also known as Spatial Augmented Reality(SAR) has attracted much attention recently and used for many division, which can augment physical objects with projected various virtual replications. However, conventional approaches towards projection mapping have faced some limitations. Target objects' geometric transformation property does not considered, and movements of flexible objects-like paper are hard to handle, such as folding and bending as natural interaction. Also, precise registration and tracking has been a cumbersome process in the past. While there have been many researches on Projection Mapping on static objects, dynamic projection mapping that can keep tracking of a moving flexible target and aligning the projection at interactive level is still a challenge. Therefore, this paper propose a new method using Unity3D and ARToolkit for high-speed robust tracking and dynamic projection mapping onto non-rigid deforming objects rapidly and interactively. The method consists of four stages, forming cubic bezier surface, process of rendering transformation values, multiple marker recognition and tracking, and webcam real time-lapse imaging. Users can fold, curve, bend and twist to make interaction. This method can achieve three high-quality results. First, the system can detect the strong deformation of objects. Second, it reduces the occlusion error which reduces the misalignment between the target object and the projected video. Lastly, the accuracy and the robustness of this method can make result values to be projected exactly onto the target object in real-time with high-speed and precise transformation tracking.

• Journal of Intelligence and Information Systems
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• v.28 no.4
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• pp.135-155
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• 2022

This study analyzes patent trends by deriving sub-technical fields of Organic Light-Emitting Diodes (OLEDs) industry, and analyzing technology value, originality, and diversity for each sub-technical field. To collect patent data, a set of international patent classification(IPC) codes related to OLED technology was defined, and OLED-related patents applied from 2005 to 2017 were collected using a set of IPC codes. Then, a large number of collected patent documents were classified into 12 major technologies using the Latent Dirichlet Allocation(LDA) topic model and trends for each technology were investigated. Patents related to touch sensor, module, image processing, and circuit driving showed an increasing trend, but virtual reality and user interface recently decreased, and thin film transistor, fingerprint recognition, and optical film showed a continuous trend. To compare the technological value, the number of forward citations, originality, and diversity of patents included in each technology group were investigated. From the results, image processing, user interface(UI) and user experience(UX), module, and adhesive technology with high number of forward citations, originality and diversity showed relatively high technological value. The results provide useful information in the process of establishing a company's technology strategy.

• Journal of Digital Convergence
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• v.18 no.6
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• pp.109-120
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• 2020

The supply chain without digitization is just a series of discrete, siloed steps taken through marketing, product development, manufacturing, and logistics, and finally into the hands of the customer. Digitization brings down those walls, and the chain becomes a completely integrated network fully transparent to all the parties involved. The ulitimate goals of digitizatized supply chain management are velocity and visibility. This network will depend on a number of key technologies including integrated planning and execution systems, supply chain analytics, autonomous logistics, smart warehousing and factory, etc, enabling companies to react to disruptions in the supply chain, and even anticipate them, by fully modeling the network, creating "what-if" scenarios, and adjusting the supply chain in real time as conditions change. This paper presents a number of studies on digitalization of supply chains and provides a discussion on issues raised in the process of technology adoption. Implications of the study findings are also provided.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.903-906
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• 2015

Over the recent industry -wide virtual world and the real world, broadcasting and telecommunications, IT technology and traditional industries, such as the fusion research has been conducted in a variety of fields. And training in the field of education is changing the paradigm of creativity to break the intrusive training center. In addition, the quality of interactive educational content technology to foster self-directed future talent is a situation that is required. The market has already surpassed the smartphone PC, smart devices and e-learning technologies are appearing new service called 'smart learning' as a new form of convergence of the educational system. In this paper, based on the direct development of a content authoring applications and Web sites, and cloud environments to the students collect and analyze patterns. Utilizing this information, we studied the curation service plans that recommend the appropriate content to fit the tastes of the learner.

• 한국HCI학회:학술대회논문집
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• 2007.02b
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• pp.55-62
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• 2007

정보통신 기술과 컴퓨터의 급속한 발달은 과거에 불가능했던 많은 일들을 가능하게 하였다. 디지털 기술의 발전은 기존의 추상적인 것을 구체적으로 체험 가능한 것으로 발전시켰으며, 이를 통해 인간은 경험을 확장 시킬 수 있게 되었다. 즉, 인간의 체험, 인식, 가치, 행위가 가상의 공간으로 무한하게 확장될 수 있기 때문이다. 이러한 배경 속에서 현대 사람들은 체험 공간이 현실 세계와는 다른 비일상적 체험과 욕구실현을 구현할 수 있는 공간이 되기를 원한다. 이에 따라서 체험 공간의 논의가 과거의 시각적 정보전달만을 위한 체험 공간이 아닌 정보와 흥미, 체험을 동시에 줄 수 있는 노력들이 요구, 진행되고 있다. 체험 공간에 있어서 엔터테인먼트 적인 요소가 효과적인 방법론으로 제시되고 있지만, 아직도 시청각적 흥미위주의 직선적인 공간의 이야기로 관람자를 일회적인 관람에서 그치게 하고 있다. 매체를 나열식으로 던져 준다고 해서 사람들이 흥미를 느끼거나 몰입을 경험하지는 못한다. 그러기 위해선 인터렉티브 스토리텔링(Interactive Storytelling)의 인터렉티비티한 요소가 체험 공간에서 효과적일 수 있다. 인터렉티비티는 인터렉티브 스토리텔링의 특징 중 하나로, 이와 같은 인터렉티비티 요소들은 관람자에게 다양한 선택과 통제의 기회를 주기 때문이다. 이에 따라서 체험 공간 속에서 관람자는 스스로 매체와 매체간의 반복과 조합을 통해 관람자 개개인이 새로운 시나리오를 쓸 수 있게 되고 체험 공간은 유동적인 공간이 될 수 있게 된다. 따라서 본 연구는 체험 공간이 관람자 스스로가 만들어가는 공간이 되고, 지각적 체험과 정신적 체험까지 경험할 수 있는 체험의 장이 될 수 있도록 인터렉티브 스토리텔링의 가치를 재해석하고자 하였다. 이러한 인터렉티브 스토리텔링이 공간 속에서 의미를 획득할 수 있는지에 대한 연구를 진행하고자 하였으며, 이를 위해 기존의 체험 공간에 대한 연구와 인터렉티브 스토리텔링의 기존 사례를 선행하였다. 이러한 과정을 통해 인터렉티브 스토리텔링이 체험 공간 안에서 사람들에게 일회적인 경험을 주는 것이 아닌 사람들이 직접 그 공간의 스토리를 만들 수 있는 새로운 체험 공간의 가능성을 가지고 있음을 발견하였다. 이에 따라서 월드컵이 열리는 대표적인 도시인 상암동에 한국 소프트웨어진흥원이 주관하여 건설되는 ‘상암 디지털 파빌리온’을 대상으로 인터렉티브 스토리텔링을 기반으로 한 체험공간 디자인을 작품 형태로 기획 되었으며, 기본적인 시나리오 컨셉을 제시하고 공간의 구조도, 체험 과정(Process)등이 제시된다. 이러한 연구는 기존 체험 공간이 직선적인 내러티브에서 벗어나 체험 공간 속 협업의 가능성을 열어주어 새로운 소통의 장을 마련해 준다는 긍정적인 효과를 기대할 수 있다.

• Smart Media Journal
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• v.9 no.2
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• pp.86-91
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• 2020

The current trend of the education market is the development of the fourth industrial revolution and the development of ICT, and various technologies are developing into edu-tech technology that is integrated into the education system. In particular, the market for edu-tech systems capable of lifelike immersive learning effects in virtual space is expanding. However, education in Korean medicine is not objective because of the absence of educational simulators and systems to train and evaluate acupuncture. In this paper, we propose an acupuncture controller and a human body model to increase the effectiveness of acupuncture point training as a follow-up study of "Design of Acupuncture Contents and Dummy for Acupuncture Point Training System". Through the proposed acupuncture controller and Dummy, the accuracy of acupuncture points for the acupuncture point data matching and content motion recognition rate is presented. In addition, the results of temperature and humidity and temperature change tests for evaluating the environmental reliability of the controller are presented.

• Journal of IKEEE
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• v.22 no.4
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• pp.1073-1078
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• 2018

As interest in the 4th Industrial Revolution increases, the CPS, in which things existing in the reality and things existing in the virtual interact with each other, is attracting attention as an important technology. Complex systems such as electric vehicles, autonomous driving, smart factories, and smart grid system are considered as core technology fields of the 4th Industrial Revolution, and many types of research have been conducted to develop it. The reliability of the system is directly related to the safety of people in case of the autonomous driving, and verification of the actual vehicle's hardware and software of ADAS is essential. In this paper, we proposed distributed simulation middleware supporting HILS for reliable verification of the complex hybrid systems.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.6
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• pp.1031-1041
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• 2020

Cloud computing technology plays an important role in the deep learning industry as deep learning services are deployed frequently on top of cloud infrastructures. In such cloud environment, virtualization technology provides logically independent and isolated computing space for each tenant. However, recent studies demonstrate that by leveraging vulnerabilities of virtualization techniques and shared processor architectures in the cloud system, various side-channels can be established between cloud tenants. In this paper, we propose a novel attack scenario that can steal internal information of deep learning models by exploiting the Meltdown vulnerability in a multi-tenant system environment. On the basis of our experiment, the proposed attack method could extract internal information of a TensorFlow deep-learning service with 92.875% accuracy and 1.325kB/s extraction speed.