• 한국컴퓨터그래픽스학회논문지
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• 제13권2호
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• pp.39-46
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• 2007

본 논문에서는 HMD 기반의 증강현실(Augmented Reality) 응용을 위한 인터페이스로 핸드폰이나 PDA 등의 모바일 장치를 사용하는 것을 제안한다. 최근 모바일 장치는 사람들 대부분이 가지고 있고, 이를 가지고 영화를 보고 인터넷을 하는 등 생활의 필수품으로 자리 잡아 가고 있어서 사용자에게 익숙한 인터페이스 기기이다. 또한, 기술의 발전으로 모바일 장치의 성능이 높아지고 있으며 프로그래밍도 가능하여 사용자에게 익숙한 인터페이스 장치로 사용하기에 적합하다. 더욱이 모바일 장치의 화면은 다양한 마커의 디스플레이를 통하여 가변 마커의 효과를 낼 수 있기 때문에 다양한 증강현실이 가능하여 모바일 장치는 사용자에게 익숙한 증강현실 인터페이스로 적합하다. 본 논문에서는 모바일 장치를 HMD 기반의 증강현실 인터페이스로 구성하는 방법을 제안하고 데모를 통해 이의 효용성을 보인다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권2호
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• pp.709-722
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• 2014

In the $21^{st}$ century, IT reform has led to the development of cyber-infrastructure owing to the outstanding enhancement of computer and network performance. The ripple effect has continued to increase. Accordingly, this study suggests a new computational research environment using mobile devices. In order to simplify the access of supercomputer, Science AppStore, task management and virtualization technologies are developed on mobile devices. User can be able to research by utilizing computational science SW such as compressible flow solver and nano device simulation tool that in installed on supercomputer in mobile environments. Also, this research environment makes it possible to monitor the simulation result and covers 14 university, 33 subjects, and 1,202 individuals.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권8호
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• pp.3689-3700
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• 2016

It is not practically feasible to apply hardware-based fault-tolerant schemes, such as hardware replication, in mobile devices. Therefore, software-based fault-tolerance techniques, such as checkpoint and rollback schemes, are required. In checkpoint and rollback schemes, the optimal checkpoint interval should be applied to obtain the best performance. Most previous studies focused on minimizing the expected execution time or response time for completing a given task. Currently, most mobile applications run in real-time environments. Therefore, it is extremely essential for mobile devices to employ optimal checkpoint intervals as determined by the real-time constraints of tasks. In this study, we tackle the problem of determining the optimal inter-checkpoint interval of checkpoint and rollback schemes to maximize the deadline meet ratio in real-time systems and to build a probabilistic cost model. From this cost model, we can numerically find the optimal checkpoint interval using mathematical tools. The performance of the proposed solution is evaluated using analytical estimates.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권9호
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• pp.3120-3137
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• 2021

Small-sized IoT wireless sensing devices can be deployed with small aircraft such as drones, and the deployment of mobile IoT devices can be relocated to suit data collection with efficient relocation algorithms. However, the terrain may not be able to predict its shape. Mobile IoT devices suitable for these terrains are hopping devices that can move with jumps. So far, most hopping sensor relocation studies have made the unrealistic assumption that all hopping devices know the overall state of the entire network and each device's current state. Recent work has proposed the most realistic distributed network environment-based relocation algorithms that do not require sharing all information simultaneously. However, since the shortest path-based algorithm performs communication and movement requests with terminals, it is not suitable for an area where the distribution of obstacles is uneven. The proposed scheme applies a simple Monte Carlo method based on relay nodes selection random variables that reflect the obstacle distribution's characteristics to choose the best relay node as reinforcement learning, not specific relay nodes. Using the relay node selection random variable could significantly reduce the generation of additional messages that occur to select the shortest path. This paper's additional contribution is that the world's first distributed environment-based relocation protocol is proposed reflecting real-world physical devices' characteristics through the OMNeT++ simulator. We also reconstruct the three days-long disaster environment, and performance evaluation has been performed by applying the proposed protocol to the simulated real-world environment.

• 한국멀티미디어학회논문지
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• 제19권5호
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• pp.918-923
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• 2016

IoT should be considered security risk environments such as various platforms and services including smart devices that can be mounted on household electric appliances, healthcare, car, and heterogeneous networks that are connected to the Internet, cloud services and mobile Apps.. In this paper, we provide analysis of new security threats, caused by open-platform of IoT and sensors via the Internet. Also, we present the key recovery mechanism that is applied to IoT. It results to have compatibility with given research, reduces network overhead, and performs key recovery without depending on key escrow agencies or authorized party.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2001년도 The Pacific Aisan Confrence On Intelligent Systems 2001
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• pp.198-201
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• 2001

Recently the wireless-internet has been spreading extensively. People are spending a large part of their time gaining access to information using a mobile device. With the rapid growth of on-line Electronic Commerce, the use of mobile devices creates a new paradigm that provides users with location-independent real time service. Although this new paradigm does have some advantages, limited process speed, low bandwidth, the low battery capacity of mobile devices, and a high rate of wireless network errors causes many overhead expenses during service time with the server. In this paper, we suggest an autonomous service delivery system, which provides mobile agent capability to users that cannot maintain a connection. We have developed the system based on java mobile agent technology. Using this system, we can provide more effective service to users when the user is sending requirements for service through a mobile device that has limited resources. Furthermore we can manage the contact server dynamically when new services are added.

• International Journal of Internet, Broadcasting and Communication
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• 제13권1호
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• pp.54-60
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• 2021

AR (Augmented Reality) is a technology that provides virtual content to the real world and provides additional information to objects in real-time through 3D content. In the past, a high-performance device was required to experience AR, but it was possible to implement AR more easily by improving mobile performance and mounting various sensors such as ToF (Time-of-Flight). Also, the importance of mobile augmented reality is growing with the commercialization of high-speed wireless Internet such as 5G. Thus, this paper proposes a system that can provide AR services via GNN (Graph Neural Network) using cameras and sensors on mobile devices. ToF of mobile devices is used to capture depth maps. A 3D point cloud was created using RGB images to distinguish specific colors of objects. Point clouds created with RGB images and Depth Map perform downsampling for smooth communication between mobile and server. Point clouds sent to the server are used for 3D object detection. The detection process determines the class of objects and uses one point in the 3D bounding box as an anchor point. AR contents are provided through app and web through class and anchor of the detected object.

• 디지털포렌식연구
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• 제12권3호
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• pp.55-70
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• 2018

모바일 기기의 다양화, 웹기술의 발달, 클라우드의 대중화로 기기에 종속되지 않는 인터넷 중심의 웹OS가 필요하게 되었다. 크롬북은 구글에서 개발한 웹OS가 탑재된 컨버터블 노트북 형태의 모바일 기기이다. 이런 웹OS 모바일 기기는 동일기기 다중 사용자의 특성과 클라우드를 통한 자료의 저장과 공유의 장점도 있지만, 보안성이 우수하고 손쉬운 증거인멸이 가능하여 포렌식 관점에서 증거를 수집하고 분석하기는 쉽지 않다. 본 논문에서는 앞으로 대중화되는 웹OS 모바일 기기인 크롬북에 대해 사용자 모드와 관리자 모드로 나누고, 클라우드 환경을 고려한 증거수집 절차와 분석 방법을 제안하고자 한다.

• 산업기술연구
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• 제29권B호
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• pp.33-39
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• 2009

The need for end-to-end security has been increased with the widespread use of mobile devices in wireless internet access applications such as mobile commerce. The WAP1.x has an end-to-end security problem that the message transmitted between the mobile device and the Web server is decrypted inside the gateway within a short time. To overcome this problem, several protocols including WAP2.0 has been proposed. These protocols require that the heavy modules such as TLS or data compression modules should be installed on the mobile device with limited resources. This paper proposes a new WTLSW(WTLS-TLS at Web server) protocol and a new WAP2.0 proxy model in order to ensure end-to-end security between the mobile device and the Web server and to be appropriate for mobile devices with limited resources.

• 한국통신학회논문지
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• 제34권8B호
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• pp.786-796
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• 2009

현재 웹 신디케이션 기술은 주로 데스크탑 환경에서 구현 활용되고 있기 때문에 이동성에 대한 고려가 되어 있지 않다. 본 논문에서는 데스크탑 기반의 웹 신디케이션 기술을 모바일 인터넷으로 확장하는데 초점을 맞추었다. 모바일 단말기에서 데스크탑 기반의 웹 신디케이션을 단순히 적용하게 되면 정기 구독으로 인해 높은 무선통신 비용을 초래할 수 있다. 본 논문은 낮은 통신 비용으로 모바일 신디케이션을 구현할 수 있는 PMS(Proxy-based Mobile Syndication) 모델을 제안한다. PMS 모델은 모바일 단말기와 웹 사이트 사이에 프록시 서버인 MWProxy를 정의한다. 프록시 서버는 웹 사이트에서 수신한 채널에서 변경된 아이템을 선택하여 간소화한 채널로 재구성함으로써 통신 비용을 줄일 수 있는 장점이 있다. 본 논문에서는 PMS 모델을 실제 휴대폰 상에서 설계 구현하고 에뮬레이터를 이용하여 성능을 평가하였다.