• The Journal of Information Systems
• /
• v.24 no.2
• /
• pp.117-138
• /
• 2015

Purpose The number of Tablet PC users has recently increased in steep, which started to offer media companies more opportunities to enter into a new business field. Based on Information System Success model, this study finds that tablet magazine's quality factors influence perceived usefulness, user satisfaction and intention of continuous use. Design/methodology/approach We conducted a survey for 20-40's Tablet PC users. After pilot study, we analyzed the main survey data by using SPSS 18.0 and AMOS 18.0, and employed structural equation modeling to test the hypotheses. Findings Our research results are summarized as follows : First, information quality has a positive impact on user satisfaction, but not on perceived usefulness. Second, service quality has a positive impact on perceived usefulness, but not on user satisfaction. Third, perceived usefulness positively influences user satisfaction. Fourth, user satisfaction positively influences the intention of continuous use. In particular we found that Tablet PC usage experience had a moderating effect on the relationship between perceived usefulness and user satisfaction.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.16 no.6
• /
• pp.1-7
• /
• 2016

As new information and communication technologies evolve, security threats are also becoming increasingly intelligent and advanced. In this paper, we analyze the time series data continuously entered through a series of periods from the network device or lightweight IoT (Internet of Things) devices by using the statistical technique and propose a system to detect abnormal behaviors of the device or abnormality based on the analysis results. The proposed system performs the first level abnormal detection by using previously entered data set, thereafter performs the second level anomaly detection according to the trust bound configured by using stored time series data based on time attribute or group attribute. Multi-level analysis is able to improve reliability and to reduce false positives as well through a variety of decision data set.

• The Journal of Asian Finance, Economics and Business
• /
• v.6 no.3
• /
• pp.283-293
• /
• 2019

The purposes of the study are threefold: (1) develop key successful factors of blockchain platform for micro-enterprises based on Balanced Scorecard (BSC), (2) find out the correlation between the key successful factors of blockchain platform for micro-enterprises, and (3) understand the perception of micro-enterprise blockchain and the difference between theoretical guidance and practical application. This study combines Interpretative Structural Modeling Method, (ISM) and Decision-Making Trial and Evaluation Laboratory (DEMATEL) to analyze the causal relationships and hierarchical structures of the 12 key successful factors of blockchain platform for micro-enterprises and understand the correlation between factors. The 12 key successful factors developed based on the four perspectives of the Balanced Scorecard, and the questionnaire designs based on the concept of DEMATEL, and then analyzed data by DEMATEL and ISM methods to understand the correlation between key factors. The research results show that the key successful factors of blockchain platform for micro-enterprises include "brand equity", "security and anti-counterfeiting", "sales growth", "transparency and clear", "trust", "consensus mechanism", "traceability", "consistency", "tracking", "innovation management", "international", "organizational adaptation", in which consumer "trust" plays an important role. Micro-enterprises can use blockchain to expand the market, provide customers with better service quality, and bring sales growth to micro-enterprises.

• ETRI Journal
• /
• v.36 no.1
• /
• pp.12-21
• /
• 2014

In this paper, we propose a new digital blind in-phase/quadrature-phase (I/Q) mismatch compensation technique for image rejection in a direct-conversion receiver (DCR). The proposed image-rejection circuit adopts DC offset cancellation and a sign-sign least mean squares (LMS) algorithm with a unique step size adaptation both for a fast and precise I/Q mismatch estimation. In addition, several performance-optimizing design considerations related to accuracy, speed, and hardware simplicity are discussed. The implementation of the proposed circuit in an FPGA results in an image-rejection ratio (IRR) of 65 dB, which is the best performance with modulated signals, along with an adaptation time of 0.9 seconds, which is a tenfold increase in the compensation speed as compared to previously reported circuits. The proposed technique will be a promising solution in the area of image rejection to increase both the speed and accuracy of future DCRs.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2016.06a
• /
• pp.258-259
• /
• 2016

일반적으로 UHD 방송 편집 시스템에서 UHD 영상의 데이터양이 막대하기 때문에 실시간 전송을 위해 코덱과 함께 압축하여 편집 서버로 혹은 편집 서버로부터 스트림 형태로 전송한다. BT.1120 형태로 전송 송출된 SDI (Serial Digital Interface) 내장 음향 데이터는 영상과 달리 보조 데이터 영역에 다른 메타 데이터들과 함께 합성되어 전송 송출되기 때문에 추출 및 합성이 상대적으로 어렵다. 특히 재생을 위해서는 영상 코덱으로부터의 출력 영상과의 동기를 고려해야 하고 음향 데이터를 BT.1120 표준에 맞춰 보조 데이터 영역에 합성해야하기 때문에 개발에 어려움이 있다. 이에 본 논문은 UHD 영상/음향 데이터의 실시간 획득/재생 시스템에서의 SDI 내장 음향 데이터의 추출 및 합성을 위한 FPGA (Field Programmable Gate Array) 기반 하드웨어 플랫폼을 제안하였다. 또한, 이를 위한 음향 데이터 추출 로직과 합성 로직을 HDL(Hardware Design Language) 설계하여 FPGA 내에 탑재하고 카메라/디스플레이/편집 서버와 통합하였다. 시험 결과 4K 60fps 데이터에서 정상적으로 영상과 음향을 분리/획득 및 합성/재생하였다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2007.06c
• /
• pp.223-228
• /
• 2007

근래 주목받는 키워드인 유비쿼터스(Ubiquitous), UCC(User Created Contents) 등은 기술적 발달과 함께한 사람들의 행동 양식 변화를 잘 반영하고 있다. 기술적인 측면에서 모바일 환경으로의 진화는 사람들에게 시공간적 제약을 없애주었으며, '호모 루덴스'로 표현된 유희적 인간의 개념은 현대인의 행동 양식을 잘 표현했다. 이중 지상파 이동 멀티미디어 방송(Digital Multimedia Broadcasting, DMB)은 방송에 있어서 시공간적 제약을 없앤 대표적인 사례이며, 'EDUTAINMENT(에듀테인먼트)'는 교육에 유희를 결합한 실례라고 하겠다. 특히 DMB는 정보와 유희의 욕구를 기본적으로 충족시킬 수 있는 방송이라는 매체를 이용한다는 점에서 에듀테인먼트의 기술적 기반이 될 수 있으며, 이를 통해 저 연령의 학습자에게 유희와 교육을 동시에 제공함으로써, 학습효과를 높일 수 있는 장점이 있다. 본 논문에서는 DMB 시스템을 위한 유아 대상의 에듀테인먼트 어플리케이션을 설계하고, 구현한다. 이 어플리케이션을 위해 스토리텔링, 음악과 악기 선택 시스템, 타임라인 및 자유표면 게임 시스템 등 DMB 시스템에 적절하며, 에듀테인먼트의 조건을 충족하는 몇 가지 방법론을 제안하여 방송을 통해 콘텐츠와 대상자가 서로 상호작용 할 수 있도록 한다. 이를 위해서는 기존 방송의 음성, 영상 서비스를 넘어 상호작용의 필수적인 요소라고 할 수 있는 데이터 서비스를 요구하며, 이는 MPEG-4 Part 11: BIFS(Binary Format for Scenes) 기술을 기반으로 그 구현에는 VRML에 기초한 BT(BIFS Text) 언어를 사용한다.

• Journal of Korea Multimedia Society
• /
• v.19 no.12
• /
• pp.1919-1926
• /
• 2016

The people who complain of pain due to voice causes such as vocal cord nodules is increasing year by year. If the voice is changed, it is possible to give to colleagues discomfort or inconvenience during conversation. In this paper, we propose a way to reduce discomfort by improving the husky voice during the conversation. A VBF (voice boosting filter) is firstly designed to improve the husky voices. This filter may further emphasize the formant frequency components than the frequency components around the formant frequency, because the value is relatively greater than the other frequency. And a fixed-point type DSP chipset, TMS320F2812 is applied to the system, the operating frequency is 150MHz. The system was implemented as a compact for use as a portable, its size is $2.5cm{\times}10cm$. Through the test using three husky voices with some type of statement, it was satisfactory in processing speed and sound quality improvement.

• Journal of Broadcast Engineering
• /
• v.3 no.1
• /
• pp.1-12
• /
• 1998

8VSB transmission system of American standard and OFDM system of European standard are to be international standards for the transmission of digital terrestrial television. When countries using PAL standard adopt the American 8VSB system which is designed under the circumstance of NTSC system, one of strong interference is the co-channel PAL interference coming from analog PAL signal. In this paper, in order to solve this problem, we classified seven types of PAL system into three groups according to the bandwidth and a new PAL-8VSB system is proposed to reject the co-channel PAL interference by using modified comb filters suitable for each group. By computer simulations of the proposed PAL-8VSB system with the co-channel PAL interference it is confirmed that the proposed comb filter results in the improvement of DIU ratio by about 9 dB.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2015.07a
• /
• pp.441-443
• /
• 2015

디지털 홀로그래픽 TV 시스템을 구현하려면 홀로그래픽 정보 획득 장치가 필요한데, 해상도 한계 때문에 홀로그램의 프린지 패턴을 상용 촬상 소자로는 직접 기록할 수 없다. 이를 극복하는 방법으로는 컬러 영상과 거리영상 정보를 얻은 후에 압축을 거쳐 수신 디스플레이단에 전송하고 이 정보로부터 3차원 모델을 형성한 후에 컴퓨터 생성 홀로그램을 생성하고 이를 회절소자를 이용하여 디스플레이하는 방법이 현재로서는 현실적인 방법이 될 것이다. 홀로그래픽 디스플레이에서는 회절소자인 공간광변조기 성능의 한계 때문에 기존 2DTV와 같은 수준의 디스플레이 구현은 매우 어렵다. 기존 공간광변조기는 픽셀피치가 커서 시야각이 매우 좁으나, 픽셀 크기를 작게 하는 동시에 공간광변조기 면적을 크게 하기에는 기술적인 어려움이 많다. 본 논문에서는 홀로그래픽 TV를 구현하는데 있어서 기술적으로 극복하고 고려해야 할 주요 요소에 대하여 분석한다.

• Proceedings of the Korea Contents Association Conference
• /
• 2009.05a
• /
• pp.99-104
• /
• 2009

The SMS(Short Message Service) in Mobile phone is a service that a text message by 80byte is transmitted and received. Recently it's used instead of voice calls. In this paper, We investigate how you take advantage of the SMS for searching information without simply as a means of voice call, and how much efficiency does the SMS have in Location Information Retrieval Services on LBS(Location-based service). Based on the previous topics, we design the information retrieval system using SMS for solveing the rates issue by existing wireless Internet access, and propose the possibility as new forms of content services.