• 대한원격탐사학회지
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• 제22권5호
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• pp.351-356
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• 2006

Based on current practical needs for geo-spatial information on mobile platform, the main theme of this study is a design and implementation of dynamic 3D terrain rendering system using spaceborne imagery, as a kind of texture image for photo-realistic 3D scene generation on mobile environment. Image processing and 3D graphic techniques and algorithms, such as TIN-based vertex generation with regular spacing elevation data for generating 3D terrain surface, image tiling and image-vertex texturing in order to resolve limited resource of mobile devices, were applied and implemented by using graphic pipeline of OpenGL|ES (Embedded System) API. Through this implementation and its tested results with actual data sets of DEM and satellite imagery, we demonstrated the realizable possibility and adaptation of complex typed and large sized 3D geo-spatial information in mobile devices. This prototype system can be used to mobile 3D applications with DEM and satellite imagery in near future.

• 정보처리학회논문지B
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• 제13B권3호
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• pp.231-238
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• 2006

본 논문에서는 모바일 게임의 전체 용량 중 상당 부분을 차지하는 이미지를 무손실로 압축하기 위한 방법을 제안하였다. 이미지의 압축률을 높이기 위해 실제로 압축을 수행하기 전에 전처리 과정에서 이미지를 재구성 한 후 RFC-1951에 정의된 Deflate 알고리즘으로 압축하였다. 전처리 과정에서는 이미지의 정보를 바탕으로 사전 기반 부호화의 특징인 사전의 크기를 얻고, 픽셀 패킹과 DPCM 예측 기법을 사용하여 이미지를 재구성하는 방법을 사용하여 일반적인 방법으로 압축할 때 보다 압축률을 향상시켰다. 제안된 압축 방법을 다양한 모바일 게임 이미지에 적용하여 압축률을 실험한 결과 기존 모바일 이미지 포맷에 비해 약 9.7%의 압축률이 향상됨을 보였다.

• 제어로봇시스템학회논문지
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• 제13권7호
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• pp.664-670
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• 2007

This study deals with image-based visual servoing for automatic recharging of mobile robot. Because mobile robot must be recharged periodically, it is necessary to detect and move to docking station. Generally, laser scanner is used for detect of position of docking station. CCD Camera is also used for this purpose. In case of using cameras, the position-based visual servoing method is widely used. But position-based visual servoing method requires the accurate calibration and it is hard and complex work. Another method using cameras is image-based visual servoing. Recently, image based visual servoing is widely used for robotic application. But it has a problem that cannot have linear trajectory in the 3-dimensional space. Because of this weak point, image-based visual servoing has a limit for real application. In case of 2-dimensional movement on the plane, it has also similar problem. In order to solve this problem, we point out the main reason of the problem of the resolved rate control method that has been generally used in the image-based visual servoing and we propose an image-based visual servoing method that can reduce the curved trajectory of mobile robot in the cartesian space.

• 한국산업정보학회논문지
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• 제14권3호
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• pp.30-36
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• 2009

국내외 의료영상 정보시스템 기술의 급격한 발달과 더불어, 언제 어디서나 의료 영상을 신속하게 판독하고자 하는 다양한 연구가 이루어지고 있다. 본 논문에서는 휴대용 개인 단말기를 통해 네트워크 전송을 통한 의학 영상을 어디서나 실시간으로 판독할 수 있는 모바일 DICOM 영상 뷰어를 설계한다. 특히, 개발된 모바일 DICOM 영상 뷰어를 통해 여러 장의 의학 영상을 동시에 볼 수 있으며, 여러 장의 의학 영상 중 특정 영상만을 선택하여 볼 수도 있다. 또한 휴대용 단말기 화면 크기에 따른 불편함을 해소하기 위하여 영상 확대 기능도 개발한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권2호
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• pp.450-470
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• 2023

Traditional cloud computing faces some challenges such as huge energy consumption, network delay and single point of failure. Edge computing is a typical distributed processing platform which includes multiple edge servers closer to the users, thus is more robust and can provide real-time computing services. Although outsourcing data to edge servers can bring great convenience, it also brings serious security threats. In order to provide image retrieval while ensuring users' data privacy, a privacy preserving image retrieval scheme in edge environment is proposed. Considering the distributed characteristics of edge computing environment and the requirement for lightweight computing, we present a privacy-preserving image retrieval scheme in edge computing environment, which two or more "honest but curious" servers retrieve the image quickly and accurately without divulging the image content. Compared with other traditional schemes, the scheme consumes less computing resources and has higher computing efficiency, which is more suitable for resource-constrained edge computing environment. Experimental results show the algorithm has high security, retrieval accuracy and efficiency.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.417-420
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• 2006

In these days, mobile application dealing with information contents on mobile or handheld devices such as mobile communicator, PDA or WAP device face the most important industrial needs. The motivation of this study is the design and implementation of mobile application using high resolution satellite imagery, large-sized image data set. Although major advantages of mobile devices are portability and mobility to users, limited system resources such as small-sized memory, slow CPU, low power and small screen size are the main obstacles to developers who should handle a large volume of geo-based 3D model. Related to this, the previous works have been concentrated on GIS-based location awareness services on mobile; however, the mobile 3D terrain model, which aims at this study, with the source data of DEM (Digital Elevation Model) and high resolution satellite imagery is not considered yet, in the other mobile systems. The main functions of 3D graphic processing or pixel pipeline in this prototype are implemented with OpenGL|ES (Embedded System) standard API (Application Programming Interface) released by Khronos group. In the developing stage, experiments to investigate optimal operation environment and good performance are carried out: TIN-based vertex generation with regular elevation data, image tiling, and image-vertex texturing, text processing of Unicode type and ASCII type.

• International Journal of Internet, Broadcasting and Communication
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• 제15권4호
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• pp.100-106
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• 2023

Bundling has become a general promotion strategy in mobile shopping context. Previous research on bundling has mostly focused on bundle frame or price frame. Even though consumers are searching and purchasing the product in mobile channels, little research has investigated the effects of bundling in mobile shopping. The objectives of this study is to examine how different product image of bundle affects consumer's perception and purchase intention differently, and how brand familiarity moderate this influence. A sample of 140 subjects participated in a within-subjects experiment. A bundling composed of two different product image (a single product vs. bundled products) was evaluated by individuals. Brand familiarity (familiar brand vs. unfamiliar brand) were manipulated to test a set of hypotheses. We found that the effectiveness of bundling does not depend on the type of product image and brand familiarity. The findings of our study provide some implications for researchers and marketers. Although there have been studies on the effects of bundle framing on consumer behavior, we suggest new insights regarding bundling based on product image and mobile shopping context.

• 한국산업융합학회 논문집
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• 제18권2호
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• pp.90-98
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• 2015

This research propose with image-based visual a new approach to design a feedback control of mobile robot. because mobile robot must be recharged periodically, it is necessary to detect and move to docking station. Generally, laser scanner is used for detect of position of docking station. CCD Camera is also used for this purpose. In case of using camera, the position-based visual servoing method is widely used. But position-based visual servoing method requires the accurate calibration and it is hard and complex work. Another method using cameras is inmage-based visual feedback. Recently, image based visual feedback is widely used for robotic application. But it has a problem that cannot have linear trajectory in the 3-dimensional space. Because of this weak point, image-based visual servoing has a limit for real application. in case of 2-dimensional movement on the plane, it has also similar problem. In order to solve this problem, we point out the main reason of the problem of the resolved rate control method that has been generally used in the image-based visual servoing and we propose an image-based visual feedback method that can reduce the curved trajectory of mobile robot in th cartesian space.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.463-466
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• 2004

This paper describes an image processing algorithm for recognition of small-obstacles using a camera and program for a mobile robot in indoor environment. Mobile robot could meet small-obstacles such as a small plastic bottle of about 1l in quantity, a small box of 7$\times$7$\times$7 cm$^3$ in volume, and so on in its designated path, and could be disturbed by them in the locomotion of a mobile robot. So, it is necessary to research on the image processing algorithm for recognition of small-obstacles using a camera and program. In this paper, 2-D the image processing algorithm for recognition of small-obstacles using a camera and program for a mobile robot in indoor environment was developed. The characteristic test of the developed program to confirm the recognition of small-obstacles was performed. It is shown that the developed program could recognize small-obstacles accurately.

• 제어로봇시스템학회논문지
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• 제9권12호
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• pp.1033-1041
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• 2003

A new visual tracking scheme is proposed for a mobile robot that tracks a moving object in 3D space in real time. Visual tracking is to control a mobile robot to keep a moving target at the center of input image at all time. We made it possible by simplifying the relationship between the 2D image frame captured by a single camera and the 3D workspace frame. To precisely calculate the input vector (orientation and distance) of the mobile robot, the speed vector of the target is determined by eliminating the speed component caused by the camera motion from the speed vector appeared in the input image. The problem of temporary disappearance of the target form the input image is solved by selecting the searching area based on the linear prediction of target motion. The experimental results have shown that the proposed scheme can make a mobile robot successfully follow a moving target in real time.