• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.4
• /
• pp.822-828
• /
• 2013

In this paper, a multi-modem for process automation of non-destructive inspection (NDI) which possibly generates various kinds of data is implemented and verified. Here, a variety of data such as control signals, text data, image data generated by inspection devices, sensors, computers are transmitted to the multi-modem via serial, Ethernet, and coaxial cable. We exploit a communication network in which powerlines are used as backbone transmission media. Thus, the implemented multi-modem has various ports and corresponding interfaces for data transmission. As a result of practical experiments, the multi-modem maintains almost constant data rate with little waveform distortion. In addition, the experiments confirm that the modem operates normally under extreme variation of temperature. It is, therefore, considered that the multi-modem can contribute significantly to implement powerline communication (PLC)-based process automation for NDI in which various kinds of data are practically generated.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37B no.12
• /
• pp.1138-1147
• /
• 2012

IEEE standard 802.16, often referred to as WiMAX, is considered a "last mile" broadband wireless access alternative to conventional DSL and Cable Internet. One extension that is recently receiving great attention is the IEEE 802.16j Mobile Multihop Relay (MMR) amendment. The focus of this amendment is the development of simple and lower cost relay stations (RSs) that can enhance network coverage and capacity. We use our proposed simple scheduling scheme for serving the SSs in a fair manner and evaluate the performance of WiMAX networks with relays, especially we analyze the impact of interference between RSs on cell throughput Through simulations and numerical analysis, we make several fundamental observations about interference aware cost effective coverage extension in such networks.

• Journal of KIISE:Computing Practices and Letters
• /
• v.16 no.6
• /
• pp.631-636
• /
• 2010

With the growing trends of communication- broadcasting convergence, a hybrid IPTV that supports both IP network-based on-demand media and terrestrial or cable-based broadcast media is gaining attraction. This paper proposes a rich media framework for hybrid IPTV with support of the latest H.264 codec. For this purpose, we design and implement a media component and a RIA run-time engine customized for TV with the hybrid media. The media component has been designed to provide a uniform and efficient application interface to the various playback methods for RF broadcast and IP-based stored or live media. For performance and portability, it exploits media stream abstraction, adaptive on-demand I-frame search, and automatic calculation of play duration. Based on the proposed media interface, we develop a RIA run-time prototype. It has been carefully designed to fully utilize the built-in graphic acceleration hardware for optimized rendering in the resource-constrained IPTV environments. Demonstration and experiment results validate the performance and usefulness of the developed framework. The framework is expected to be used effectively to support graphics and hybrid media in the applications of IPTV-based VOD, advertisement, and education.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.9A
• /
• pp.983-990
• /
• 2004

In this paper, we calculated the input impedance of the power line communication(PLC) networks using medium voltage power line. First of all, we proposed input and output teoninal model of PLC network, and calculated the input impedance applying the attenuation constants by radiation loss, conductor loss, dielectric loss. From the calculation result, we knew that the attenuation by radiation loss was largest, and the input impedance appears like a standing wave fonn with a fixed cycle because the high reflection at the input terminal for the characteristic impedance of the power line is very large. And also the cycle of input impedance depends on the coaxial cable length, and the amplitude depends on the characteristic impedance of power line and losses. From the measurement result, calculated result was very similar to the measured result.

• The Journal of the Korea Contents Association
• /
• v.12 no.2
• /
• pp.86-93
• /
• 2012

The emergence of cable TV, satellite broadcasting and IPTV provides viewers with a variety of TV programs. However, viewers' desire for watching their favorite TV program at convenient time has increased because of insufficient spare time. As an increase in smart phone market has accelerated an entry into "the age of smart network media" since 2009, mobile media suggests services connected to other digital devices. Recently, there has been growing interest in TV controling system of smart phone. Therefore, the present study aims to provide an concept of the smart phone application which recommends contents of TV program by analyzing personal watching pattern. To suggest detailed direction of the interaction and UI design, we analyzed previous research and examples of TV controlling applications and products. In addition, public opinion survey was carried out to rationalize this study and suggest suitable UI structure.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.12B
• /
• pp.1522-1536
• /
• 2011

Due to the advance of broadband communication networks including the Internet, the release of diverse media, and the busy life cycle of modern people, it became difficult to watch TV programs strictly according to the program schedule. Instead, demand to download and watch the programs at any time on TV is increasing. In order to meet the demand, terrestrial DTV broadcasters developed a TV service which provides various on-demand contents by integrating terrestrial DTV network and the Internet without enforcing viewers to subscribe broadcasting services such as IPTV or CableTV, and standardized it as OHTV(Open Hybrid TV). In this paper, we explain the current status of OHTV standard and worldwide hybrid TV services and their technical standards. We also provide a strategy for the next version of OHTV standard in order to enhance the value of OHTV.

• Journal of the Korean Solar Energy Society
• /
• v.34 no.1
• /
• pp.81-90
• /
• 2014

The Jeju-Korea power system is a small-sized network with a system demand ranging from a autumn minimum of 350MW to a summer peak of 716MW. Because Jeju island is well exposed to north-east winds with high speed, applications to connect to Jeju power system are flooded. Considering physical/environmental constraints, Jeju Self-governing Province has also target for the wind power capacity of 1,350MW by 2020. It amounts to two or three times of Jeju average-demand power and wind power limit capacity announced by Korea Power Exchange (KPX) company. Wind farm connection agreements will be signed to maximize utilization of wind resource. In spite of submarine cable HVDC connected to Korea mainland, Jeju power system is independently operated by frequency and reserve control. This study reevaluates wind power limit based on the KPX criteria from 2016 to 2020. First of all wind power generation limit are affected by off-peak demand in Jeju power system. Also the possibility capacity rate of charging wind power output is evaluated by using energy storage system (ESS). As a result, in case of using 110MWh ESS, wind power limit increases 33~55MW(30~50% of ESS), wind power constraint energy decreases from 68,539MWh to 50,301MWh and wind farm capacity factor increases from 25.9 to 26.1% in 2020.

• Journal of Digital Convergence
• /
• v.12 no.5
• /
• pp.501-515
• /
• 2014

The enforcement of the digital switch been two years, but more than half of the viewers are still not enjoying the benefits of it. Therefore, the government proposed that 8VSB transmission method so that majority of the viewer is able to enjoy the benefits of a digital switch. However, the claim has been suggested that 8VSB transmission method will have negative impacts on broadcast market feedback. In this regard, this study verified the effect of 8VSB and the method of minimization on the broadcast market. This study has conducted in-depth interviews concerned experts to achieve this purpose. Results of an interview revealed that the negative impact on the market of content and platforms, network is very small. In other words, the majority of the experts argued that the policy of government about 8VSB transmission are inadequate and it is improved to broaden the choice of the broadcast consumer.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.26 no.3
• /
• pp.701-712
• /
• 2016

The number of subscriber of digital pay TV service such as Digital Cable TV and IPTV is increasing from various kind of service provider world widely. These services require personal information of users to provide VOD(Video on Demand) and customized contents. Therefore, massive amount of personal information collected by service provider can cause social confusion such as leakage of privacy and property damage. This paper investigates whether broadcasting stations are providing enough notification for privacy policy and methodology of collecting private information in proper way. Furthermore, we analyze actual network traffic of IPTV service between user and service provider to suggest solution of privacy protection along with current status analysis.

• Convergence Security Journal
• /
• v.8 no.4
• /
• pp.73-80
• /
• 2008

In this paper, we developed a WMS (Warehouse Management System) Simulator. There is no Simulator that supports optimized design for Warehouse, consider goods which storage in warehouse and using RFID and USN based on cable wireless network. Also, there is no tool for monitoring which decides delivery time with information about temperature, humidity and illumination, after goods are stocked into warehouse. In this paper, WMS Simulator Implements function of drawing a blueprint. The Simulator that can analyze moving information of Palette with RFID tags and the change about temperature, humidity and illumination is developed in this paper. Inventory accuracy, space equipment practical use, and decreasing of picking time, faulty storage and product loss by product processing ability elevation are expected by designing the way of operating of warehouse for most suitable use of system in physical distribution through these treatise.