• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권2호
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• pp.673-694
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• 2021

In this paper, we intend to study the energy efficiency (EE) optimization for a simultaneous wireless information and power transfer (SWIPT)-based distributed antenna system (DAS). Firstly, a DAS-SWIPT model is formulated, whose goal is to maximize the EE of the system. Next, we propose an optimal resource allocation method by means of the Karush-Kuhn-Tucker condition as well as an ergodic method. Considering the complexity of the ergodic method, a suboptimal scheme with lower complexity is proposed by using an antenna selection scheme. Numerical results illustrate that our suboptimal method is able to achieve satisfactory performance of EE similar to an optimal one while reducing the calculation complexity.

• Journal of information and communication convergence engineering
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• 제18권3호
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• pp.194-200
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• 2020

Cities in Indonesia include diverse scattered industrial centers comprising industries that can sustain the existing economic pace. For industrial data collection, the city government still relies on census that consumes extensive time and money. The public are unfamiliar with industries owing to their lack of industry information; therefore, the market share is not optimal. In addition, the opportunity to procure investors for business development is limited. A Geographic Information System (GIS) is a computer system that can record, store, write, analyze, and display geographical data. Using the Rapid Application Development (RAD) method, GIS was developed on a website platform to provide information on industry profiles, types of production, investment values, industry maps, and industrial locations in each village and sub-district to a wider community. The RAD method was chosen compared to the waterfall method because it could accelerate website development process.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 1999년도 가을 학술발표논문집 Vol.26 No.2 (3)
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• pp.783-785
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• 1999

Distributed Object Systems are very complex. So, it is difficult to see overall relationship among objects participated in the system. Moreover the performance tuning or maintenance are also important issues of it. So, it needs a way to view the system with low-cost and an efficient method. One of solutions is a visualization tool or system. In this paper, we proposed a tracing facility for Java-based distributed object system, especially RM(Remote Method Invocation). Our up-coming visualization system will use two phase hybrid post-mortem/on-the-fly technique. To support it, the fundamental tracing part must have some flexible and dynamic mechanism. The main idea of our tracing technique is the Plug-in Sensor Model(PSM). The relationship between tracing (monitoring) part and visualization part is closely related. So, we considered the appropriate factors for visualization. We developed 'Traced RMI(TRMI)'. For more precise visualization of a working system, the casuality of events has to be preserved. TRMI can support global event ordering.

• 대한공간정보학회지
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• 제19권2호
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• pp.75-83
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• 2011

1995년 이후 국가지리정보구축사업의 일환으로 전국적으로 구축되었던 공간정보시스템의 통합과 연계에 대한 연구가 끊임없이 이어지고 있다. 하지만 공간정보연계와 통합을 위한 체계적인 기준이 모호할 뿐만 아니라 각각의 구축기관마다 공간정보에 대한 식별 ID가 상이하게 구축되어 있어 연계에 어려움을 주고 있는 실정이다. 본 연구에서는 국가표준의 공간정보참조체계를 기반으로 하는 UFID를 부여하기 위해 공간정보객체의 중첩방안을 제시하고 이에 대한 중첩률을 분석하고자 한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 컴퓨터소사이어티 추계학술대회논문집
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• pp.77-80
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• 2003

Complying with highly demand of information through internet. the utility of computer and network is rapidly provided with to schools. This situation brings about many problems. For example, the stolen information through false identification(Hacking) is the most greatest concern. In this paper it tells that the efficient way of preservating computer use is by using operating system of Open Source, which is Linux system. Further more, it shows the system which was organized by IP-Tabling (offered service-Packet Filtering method from the Linux system) functions well as a security system.

• Journal of Information Processing Systems
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• 제15권5호
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• pp.1218-1230
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• 2019

This study proposes a novel video traffic flow detection method based on machine vision technology. The three-frame difference method, which is one kind of a motion evaluation method, is used to establish initial background image, and then a statistical scoring strategy is chosen to update background image in real time. Finally, the background difference method is used for detecting the moving objects. Meanwhile, a simple but effective shadow elimination method is introduced to improve the accuracy of the detection for moving objects. Furthermore, the study also proposes a vehicle matching and tracking strategy by combining characteristics, such as vehicle's location information, color information and fractal dimension information. Experimental results show that this detection method could quickly and effectively detect various traffic flow parameters, laying a solid foundation for enhancing the degree of automation for traffic management.

• 한국컴퓨터정보학회논문지
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• 제5권4호
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• pp.120-125
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• 2000

기존의 인터넷 망 관리에 사용되는 SNMP(Simple Network Management Protocol)는 망 관리 정보 수집을 위한 폴링과 이에 대한 응답 트래픽으로 관리자 시스템(Management System)이 관리하는 피관리 시스템(Agent System)이 많아지면 망의 과부하를 가져올 수 있다. 본 논문에서는 기존의 SNMP에서 사용하는 폴링 방법을 개선하여 피관리 시스템이 많은 경우에 망의 과부하를 줄일 수 있는 그룹 폴링 방법을 제안하였다. 제안한 방법은 피관리 시스템들을 그룹으로 나누어 정보를 수집하는 방식으로, 기존의 방식에 비해 응답 지연시간과 통신 부하가 줄어서 피관리 시스템의 수가 많은 경우나 폴링 횟수가 많은 경우, 제안된 그룹 폴링 방법을 이용하는 것이 효율적이었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.5-7
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• 1996

We propose a triangulation method based on stereo vision angles. We setup stereo vision systems which extract the depth information to a moving object by detecting a moving object using difference image method and obtaining the depth information by the triangulation method based on stereo vision angles. The feature point of a moving object is used the geometrical center of the moving object, and the proposed vision system has the accuracy of 0.2mm in the range of 400mm.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2007년도 학술대회 1부
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• pp.268-273
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• 2007

In this paper, we present effective methods for automatic music recommendation system which automatically recommend music by signal processing technology. Conventional music recommendation system use users’ music downloading pattern, but the method does not consider acoustic characteristics of music. Sometimes, similarities between music are used to find similar music for recommendation in some method. However, the feature used for calculating similarities is not highly related to music characteristics at the system. Thus, our proposed method use high-level music characteristics such as rhythm pattern, timbre characteristics, and the lyrics. In addition, our proposed method store features of music, which individuals queried, to recommend music based on individual taste. Experiments show the proposed method find similar music more effectively than a conventional method. The experimental results also show that the proposed method could be used for real-time application since the processing time for calculating similarities between music, and recommending music are fast enough to be applicable for commercial purpose.

• 대한원격탐사학회지
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• 제37권1호
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• pp.161-167
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• 2021

This paper presents the method to quantitatively evaluate the uncertainty of the semi-empirical Bidirectional Reflectance Distribution Function (BRDF) model for Himawari-8/AHI. The uncertainty of BRDF modeling was affected by various issues such as assumption of model and number of observations, thus, it is difficult that evaluating the performance of BRDF modeling using simple uncertainty equations. Therefore, in this paper, Monte-Carlo method, which is most dependable method to analyze dynamic complex systems through iterative simulation, was used. The 1,000 input datasets for analyzing the uncertainty of BRDF modeling were generated using the Second Simulation of a Satellite Signal in the Solar Spectrum (6S) Radiative Transfer Model (RTM) simulation with MODerate Resolution Imaging Spectroradiometer (MODIS) BRDF product. Then, we randomly selected data according to the number of observations from 4 to 35 in the input dataset and performed BRDF modeling using them. Finally, the uncertainty was calculated by comparing reproduced surface reflectance through the BRDF model and simulated surface reflectance using 6S RTM and expressed as bias and root-mean-square-error (RMSE). The bias was negative for all observations and channels, but was very small within 0.01. RMSE showed a tendency to decrease as the number of observations increased, and showed a stable value within 0.05 in all channels. In addition, our results show that when the viewing zenith angle is 40° or more, the RMSE tends to increase slightly. This information can be utilized in the uncertainty analysis of subsequently retrieved geophysical variables.