• 대한전기학회논문지:전력기술부문A
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• 제53권6호
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• pp.316-323
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• 2004

This paper develops an ADWHM(Advanced Digital Watt-Hour Meter) which integrates and implements the voltage management data record function and the load management data record function in the electronic watt-hour meter. ADWHM is developed based on PIC16F874 which is 8bit micro-controller of RISK type for the easy of programing and maintenance, and electronic power signal processing module is located at front of it to reduce the computing load of processor. Also, a 16kbyte EEPROM is used to record the voltage management data and load management data for a week as well as watt-hour data and USART communication mode is used to transfer data from ADWHM to PC. The accuracy of the voltage and unt measuring for ADWHM is verified by identifying the LCD display values of the ADWHM after the voltage signals of id levels from digital function generator is applied to PT(Potential Transformer) and CT(Current Transformer) output under state which it is separated from real power line. On the its basic functions such as watt-hour data recording function, voltage management data recording function and load management data recording function was verified by showing data for three days among the collected data to PC by RS232C communication from ADWHM which was connected to real power lines for a week.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권5호
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• pp.2326-2345
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• 2016

For the compression of color images, a common bitmap usually is generated to replace the three individual bitmaps that originate from block truncation coding (BTC) of the R, G and B channels. However, common bitmaps generated by some traditional schemes are not the best possible because they do not consider the minimized distortion of the entire color image. In this paper, we propose a near-optimized common bitmap scheme for BTC using Binary Ant Colony Optimization (BACO), producing a BACO-BTC scheme. First, the color image is compressed by the BTC algorithm to get three individual bitmaps, and three pairs of quantization values for the R, G, and B channels. Second, a near-optimized common bitmap is generated with minimized distortion of the entire color image based on the idea of BACO. Finally, the color image is reconstructed easily by the corresponding quantization values according to the common bitmap. The experimental results confirmed that reconstructed image of the proposed scheme has better visual quality and less computational complexity than the referenced schemes.

• 한국인터넷방송통신학회논문지
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• 제23권3호
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• pp.59-64
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• 2023

화재 재난방송 시스템에서는 아날로그, 디지털, 네트워크 디지털 전관 방송 시스템으로 나뉘며, 네트워크 디지털 전광 방송 시스템에서 중요한 사양은 낮은 대기 시간(Low-latency), 높은 샘플링 레이트, 다채널 입출력이다. 기존에 데이터링크 층의 MAC 주소 기반으로 구별하는 AoE(Audio over Ethernet) 방법을 널리 사용하고 있다. 그러나 이 방법은 복잡성과 비용이 증가하는 문제가 있다. 이에 본 제안은 AoIP(Audio over Internet Protocol)/UDP 방식으로 별도의 중복적인 네트워크가 필요 없이 IP(Internet Protocol) 주소로 손쉽게 구별하는 통신을 할 수 있어 네트워크를 자유롭게 사용 구성하고 복잡도를 낮추어 비용을 낮출 수 있도록 제안한다. AoIP/UDP 방식으로 구현 후 실험결과 2.66ms 대기 시간 성능으로 동등한 성능으로 비용의 개선함을 보였다.

• Journal of information and communication convergence engineering
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• 제9권3호
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• pp.276-281
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• 2011

This paper presents a method of constructing the switching function using edge-valued decision diagrams. The proposed method is as following. The edge-valued decision diagram is a new data structure type of decision diagram which is recently used in constructing the digital logic systems based on the graph theory. Next, we apply edge-valued decision diagram to function minimization of digital logic systems. The proposed method has the visible, schematic and regular properties.

• Journal of Information Processing Systems
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• 제15권4호
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• pp.890-903
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• 2019

The single carrier frequency domain equalization (SC-FDE) technology is an important part of the broadband wireless access communication system, which can effectively combat the frequency selective fading in the wireless channel. In SC-FDE communication system, the accuracy of timing synchronization directly affects the performance of the SC-FDE system. In this paper, on the basis of Schmidl timing synchronization algorithm a timing synchronization algorithm suitable for FPGA (field programmable gate array) implementation is proposed. In the FPGA implementation of the timing synchronization algorithm, the sliding window accumulation, quantization processing and amplitude reduction techniques are adopted to reduce the complexity in the implementation of FPGA. The simulation results show that the algorithm can effectively realize the timing synchronization function under the condition of reducing computational complexity and hardware overhead.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 춘계종합학술대회
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• pp.359-362
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• 2001

수중통신시스템은 과거 AM, FM 변ㆍ복조방식을 이용한 아날로그시스템이 개발되어 왔고, 최근에는 디지털 하드웨어 기술의 발전으로 디지털 변ㆍ복조 방식을 이용한 디지털통신시스템이 개발 이용되고 있다. 수중통신에 있어서 손실, 배경 잡음, 다중경로 등의 해양 환경 특성을 극복하는 것은 신뢰성 있는 통신 환경을 이룩하는데 중요하다. 특히 해면과 해저로 경계 지워진 천해 환경에서 다중경로에 의한 영향은 수중통신시스템의 성능을 좌우하는 중요한 요소 중의 하나이다. 이런 다중경포의 통신채널은 일반적으로 수지 채널과 수평채널로 구분 짓고 있으며, 수직채널은 직접 파와 반사 파의 경로차이가 크고, 수평채널은 직접 파와 반사 파의 경로차이가 수지채널에 비해 상대적으로 적게 나타난다. 본 논문에서는 수치모의 실험을 통해 세 가지 디지털 변ㆍ복조 방식인 FSK, BPSK, DPSK의 수직ㆍ수평 다중경로 통신채널에 대한 성능을 비교 검토하였다.

• 한국전자통신학회논문지
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• 제7권1호
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• pp.135-139
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• 2012

LTE (long-term evolution) 를 비롯한 4G 이동통신 기지국 시스템에 있어서 최근에 DU(digital unit)와 RU(radio unit) 로 분리된 형상의 기지국들이 많이 등장하고 있다. 이러한 형태의 기지국에서 DU 는 전화국사에 설치하고 RU 는 옥외에 설치하는 형태로서, DU와 RU 간의 분리 가능한 거리는 이동통신 망 설계를 하는데 있어서 매우 중요한 요소가 된다. 하지만, DU와 RU 간 허용거리는 이동통신의 물리계층 기술에 의해 제약을 받을 수 있다. 본 논문에서는 FDD (frequency division duplexing) 기반의 4G 이동통신 시스템에서 Closed-Loop MIMO (multiple input multiple output) 기술에 의해 제한되는 DU와 RU 간 한계거리에 대해 분석하였다. DU와 RU 간 한계거리는 이동통신 시스템의 동작 주파수에 따라 다른 결과를 나타내며, 2 GHz의 동작주파수를 가정할 경우에는 약 11 km의 한계거리를 가지는 것으로 분석되었다.

• Journal of Information Processing Systems
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• 제13권4호
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• pp.653-667
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• 2017

The significant advances in information and communication technologies are changing the process of how information is accessed. The internet is a very important source of information and it influences the development of other media. Furthermore, the growth of digital content is a big problem for academic digital libraries, so that similar tools can be applied in this scope to provide users with access to the information. Given the importance of this, we have reviewed and analyzed several proposals that improve the processes of disseminating information in these university digital libraries and that promote access to information of interest. These proposals manage to adapt a user's access to information according to his or her needs and preferences. As seen in the literature one of the techniques with the best results, is the application of recommender systems. These are tools whose objective is to evaluate and filter the vast amount of digital information that is accessible online in order to help users in their processes of accessing information. In particular, we are focused on the analysis of the fuzzy linguistic recommender systems (i.e., recommender systems that use fuzzy linguistic modeling tools to manage the user's preferences and the uncertainty of the system in a qualitative way). Thus, in this work, we analyzed some proposals based on fuzzy linguistic recommender systems to help researchers, students, and teachers access resources of interest and thus, improve and complement the services provided by academic digital libraries.

• 인터넷정보학회논문지
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• 제15권2호
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• pp.143-147
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• 2014

본 논문에서는 디지털 라디오 표준인 DRM(Digital Radio Mondiale) 및 DRM+(Digital Radio Mondiale Plus) 시스템을 이더넷모드에서 분석할 수 있는 다중화분산접속(MDI, Multiplex Distribution Interface) 분석기를 설계한다. 제안하는 MDI 분석기는 메모리 공유 기술을 가진 공통 블록 모듈을 사용하여 MDI 패킷들의 부하를 감소시키며, 차세대 디지털 라디오 방송시스템을 위해 수신된 MDI 패킷을 통해 IP(Internet Protocol)와 DRM/DRM+ 시스템의 FAC(Fast Access Channel)/SDC(Service Description Channel) 구성정보를 확인할 수 있다.

• Agribusiness and Information Management
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• 제5권1호
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• pp.31-41
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• 2013

The research assesses the impact of a digital procurement (e-purjee) system for sugarcane growers in Bangladesh. The system itself is simple, transmitting purchase orders to local farmers via SMS text notification. It replaces a traditional paper-based system fraught with low reliability and delivery delays. Applying expected value theory, and using decision tree representations to depict growers' decision-making complexity in an information-asymmetric environment, we compute outcomes for the strategies and sub-strategies of ICT vs. traditional paper-based order management from the sugarcane growers' perspective. The study results show that the digital procurement system outperforms the paper-based system by tangibly reducing growers' economic losses. The digital system also appears to benefit growers non-monetarily, because of reduced uncertainty and a higher level of perceived fairness. Sugarcane growers appear to value the non-monetary benefits even higher than the economic advantages of the e-purjee system.