• Journal of The Korean Astronomical Society
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• v.27 no.2
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• pp.191-201
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• 1994

We propose to use the entropy of power spectra defined in the frequency domain for the deconvolution of extended images. Spatial correlations requisite for extended sources may be insured by increasing the role of power entropy because the power is just a representation of spatial correlations in the frequency domain. We have derived a semi-analytical solution which is found to severely reduce computing time compared with other iteration schemes. Even though the solution is very similar to the well-known Wiener filter, the regularizingng term in the new expression is so insensitive to the noise characteristics as to assure a stable solution. Applications have been made to the IRAS $60{\mu}m\;and\;100{\mu}m$ images of the dark cloud B34 and the optical CCD image of a solar active region containing a circular sunspot and a small pore.

• Journal of Korea Water Resources Association
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• v.53 no.6
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• pp.463-467
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• 2020

The main feature of this study is to automatically synthesize square images by sending aerial photographs and images from unmanned aerial vehicles (drons). It may be applicable to the cloud server, and to apply analytical algorithms for the suitable purpose of image processing. Drone imaging analysis is a process that can be used in various fields such as finding contaminated area of green algae, monitoring forest fire, and managing crop cultivation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.1025-1026
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• 2015

With the development of sensor, wireless mobile communication, embedded system and cloud computing, the technologies of Internet of Things have been widely used in real word. Connecting wireless sensor networks with traditional communication networks or Internet, IoT gateway plays an important role in IoT applications. It facilitates the integration of wireless sensor networks and mobile communication networks or Internet. The IoT gateway is a key component in IoT application systems. But It has lot of security issues. We analyzed the issues of security and privacy.

• Journal of Information Technology Applications and Management
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• v.20 no.4
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• pp.19-31
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• 2013

There is tremendous increasing demand on spectrum resource which is boosted by spread of cloud computing and M2M telecommunication as well as smart phone and tablet PC. Recently, spectrum sharing technology has drawn attention to the spectrum policy makers as a promising way to overcome limitation of scarce spectrum resource. To succeed in commercialization of spectrum sharing technology, it is necessary to prospect the future business ecosystem of spectrum sharing and develop appropriate policies and laws at the same time along with the advance of spectrum sharing technology. The purpose of this paper is to prospect future spectrum sharing ecosystem and analyze business ecosystem of spectrum sharing with casual loop map. With the causal map and system dynamics method, it is possible to analyze feedback loops which is not limited to linear thinking and build policies which optimize positive dynamics in business ecosystem of spectrum sharing.

• Annual Conference of KIPS
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• 2018.10a
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• pp.93-96
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• 2018

메시지 전달 인터페이스(MPI)는 분산 및 병렬 처리에서 정보의 교환에 대해 기술하는 표준으로 사용자에게 표준 인터페이스를 제공한다. 그러나, 사용자 레벨의 표준화를 지원하고 있으나 MPI 라이브러리와 런타임 환경은 버전과 종류마다 상이하여 호환이 되지 않아 실행 환경 측면에서의 이식성에 대한 문제가 존재한다. 이러한 MPI 어플리케이션의 이식성 문제를 해결하는 방안으로 컨테이너 기반의 HPC 환경이 가능한 솔루션 중 하나이다. 본 연구에서는 컨테이너 기반의 HPC 환경을 제공하는 대표적인 도구인 Docker, Singularity, Shifter에 대한 MPI 어플리케이션의 이식성에 필요한 고려사항과 실행 방법을 비교 분석한다.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.505-507
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• 2003

This paper describes techniques for the automated creation of geometric 3D models of the urban area us ing two 2D laser scanners and aerial images. One of the laser scanners scans an environment horizontally and the other scans vertically. Horizontal scanner is used for position estimation and vertical scanner is used for building 3D model. Aerial image is used for registration with scan data. Those models can be used for virtual reality, tele-presence, digital cinematography, and urban planning applications. Results are shown with 3D point cloud in urban area.

• Communications for Statistical Applications and Methods
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• v.27 no.4
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• pp.397-412
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• 2020

In this paper, a notion of data depth is used to propose nonparametric multivariate two sample tests for difference between scale parameters. Data depth can be used to measure the centrality or outlying-ness of the multivariate data point relative to data cloud. A difference in the scale parameters indicates the difference in the depth values of a multivariate data point. By observing this fact on a depth vs depth plot (DD-plot), we propose nonparametric multivariate two sample tests for scale parameters of multivariate distributions. The p-values of these proposed tests are obtained by using Fisher's permutation approach. The power performance of these proposed tests has been reported for few symmetric and skewed multivariate distributions with the existing tests. Illustration with real-life data is also provided.

• 한국가시화정보학회:학술대회논문집
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• 2002.11a
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• pp.15-18
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• 2002

We propose an image based three-dimensional shape determination system. The shape, and thus the three-dimensional coordinate information of the 3-D object, is determined solely from captured images of the 3-D object from a prescribed set of viewpoints. The approach is based on the shape from silhouette (SFS) technique and the efficacy of the SFS method is tested using a sample data set. This system may be used to visualize the 3-D object efficiently, or to quickly generate initial CAD data for reverse engineering purposes. The proposed system potentially may be used in three dimensional design applications such as 3-D animation and 3-D games.

• Annual Conference of KIPS
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• 2015.10a
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• pp.763-766
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• 2015

Smart Healthcare System as an Open Platform (Shesop) is an integrated healthcare system and have several features, one of them is Steppy Application. Steppy does count your step and display on Shesop website. In this system security issues are not properly addressed, while Personal Health Record (PHR) patient stored in the cloud platform could be at risk. In fact, the huge electronic information available online, people needs reliable and effective technique for privacy preserving. In order to improve the security of data which are displayed on the Shesop website, so that anyone who access could not tamper without permission. Recently Xu et al. showed a pseudonym scheme using smart card as a solution in e-health systems which uses discrete logarithm problem with cyclic group. In this paper, we adopt their scheme and use it application into smartphone using Near Field Communication (NFC) to construct security in Steppy apps.

• Annual Conference of KIPS
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• 2015.10a
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• pp.710-713
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• 2015

21세기 모바일 디바이스의 급속한 확산과 클라우드 컴퓨팅의 발전은 개인정보의 흐름을 개인용 컴퓨터에서 모바일 디바이스로 이동시켰다. 이에 따라 포렌식에서도 모바일 디바이스의 디지털 데이터를 중요한 증거로 인식하고 이에 대한 연구가 활발하게 진행 중이다. 하지만 클라우드 환경에서는 일반적으로 클라우드라고 인식되는 외부에 데이터를 저장하기 때문에 사용자 측의 디바이스에서는 디지털 증거의 획득이 쉽지 않다. 본 논문에서는 일반 사용자에게 클라우드 서비스로 대표되는 N드라이브, 다음 클라우드와 같은 클라우드 스토리지 서비스를 안드로이드 환경에서 이용해 보고 디바이스 내부에 생성되는 정보 중 디지털 포렌식의 관점에서 활용 가능한 정보를 수집 및 분석해보려 한다.