• International Journal of Internet, Broadcasting and Communication
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• v.10 no.1
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• pp.1-10
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• 2018

In cognitive radio (CR), secondary users (SUs) are able to sense the absence of primary users (PUs) in the spectrum. Then, SUs use this information to opportunistically access the licensed spectrum in the PUs' absence. In this paper, we present an implementation of real-time video transmission with spectrum-sensing between two points using GNU Radio and a National Instruments 2900 Universal Software Radio Peripheral (USRP). In our project, spectrum-sensing is implemented at both transmitter and receiver. The transmitter senses the channel, and if the channel is free, a video signal (which could be a real-time signal from a video file) will be modulated and processed by GNU Radio and transmitted using a USRP. A USRP receiver also senses the channel, but in contrast, if the channel is busy, the signal is demodulated to reproduce the transmitted video signal. This project brings in several challenges, like spectrum-sensing in the devices' environment, and packets getting lost or corrupted over the air.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.2
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• pp.57-65
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• 2008

Wireless sensor networks achieve environment monitoring and controlling through use of small devices of low cost and low power. Such network is comprised of several sensor nodes, each having a microprocessor, sensor, actuator and wired/wireless transceiver inside a small device. In this paper, we employ the sensor networks in order to design and implement a real-time vehicle safety system. Such system can inform the safe velocity in a specific weather condition to drivers in advance through analyzing the weather data collected from sensor networks. As a result, the drivers can prevent effectively accidents by controlling their car speed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.6
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• pp.1496-1502
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• 1998

In this paper, a real-time audio broadcasting service system which is robust to loaded traffic on the Internet is developed. For implementing reliable real-time data transfer, the transfer characteristics of TCP/IP and UDP/IP was compared and analyzed. For lost packet recovery, redundant audio data algorithm was used and interleaving technique was applied for scattering consecutive packet loss. Test results showed, when using TCP/IP, pause occurred during playback, and when using UDP/IP, a stable receive rate was noticeable but the quality of the sound was lower than that of uisng TCP/IP. The recovery rate using redundant audio data and interleaving technique is shown in Fig. 9 and the delay is shown in Fig 4.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.4
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• pp.43-49
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• 2021

A small infrared image homing system is a tracking system that has an infrared image sensor that identifies a target through the day and night infrared image processing of the target on the ground and searches for and detects the target with respect to the main target. This paper describes the development of a board equipped with a high-speed CPU and FPGA (Field Programmable Gate Array) to identify target through real-time image processing by acquiring target information through infrared image. We propose a CPU-FPGA combining architecture for CPU and FPGA selection and video signal processing, and also describe a controller design using FPGA to control infrared sensor.

• International journal of advanced smart convergence
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• v.7 no.3
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• pp.92-100
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• 2018

In this paper, we propose a fault-tolerant scheduling scheme with energy efficiency for real-time periodic tasks on DVFS-enabled multicore processors. The scheme provides the tolerance of a permanent fault with the primary-backup task model. Also the scheme reduces the energy consumption of real-time tasks with the fully overlapped execution between each primary task and its backup task, whereas most of previous methods tried to minimize the overlapped execution between the two tasks. In order to the leakage energy loss of idle cores, the scheme activates a part of available cores with rarely used cores powered off. Evaluation results show that the proposed scheme saves up to 82% energy consumption of the previous method.

• International journal of advanced smart convergence
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• v.7 no.4
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• pp.147-153
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• 2018

This study is about the interactive self-portrait which provides the experience of self-consciousness reflection of the viewer to modern people who are easily alienated in rapid social change. We proposed interactive self-portrait is implemented by an interactive mirror that reproduces the appearance of the viewer acquired using a webcam. The interactive mirror, which can directly project its own image, is drawn by searching news articles in real time and using the extracted characters as pixel information in real time. The viewer has the opportunity to experience a new style of active self-expression while watching his/herself composed of news characters that are issues of modern society. The virtual self-portrait designed with news characters can attract viewers' attention by visually expressing the interests of modern people and can act as an incentive to generate positive interaction.

• International journal of advanced smart convergence
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• v.11 no.3
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• pp.56-63
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• 2022

Cyber-physical systems (CPSs) can solve real problems by utilizing closely connected resources in the cyber world. Most problems arise because the physical world is uncertain and unpredictable. To address this uncertainty, information pouring from numerous devices must be collected in real-time, and each interconnected device must share the information. At this time, CPS must meet timing-related techniques and strict timing constraints that can deliver accurate information within predefined deadlines in order to interact closely beyond simply connecting the cyber and physical worlds. Timing errors in safety-critical systems, such as automobiles, aviation, and medical systems, can lead to catastrophic disasters. In this paper, we classify timing problems into two types: real-time delay and synchronization problems. The results of this study can be used in the entire process of CPS system design, implementation, operation, verification, and maintenance. As a result, it can contribute to securing the safety and reliability of CPS.

• International journal of advanced smart convergence
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• v.9 no.1
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• pp.109-112
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• 2020

Many devices are connected on the internet to give functionalities for interconnected services. In 2020', The number of devices connected to the internet will be reached 5.8 billion. Moreover, many connected service provider such as Google and Amazon, suggests edge computing and mesh networks to cope with this situation which the many devices completely connected on their networks. This paper introduces the current state of the introduction of the wireless mesh network and edge cloud in order to efficiently manage a large number of nodes in the exploding Internet of Things (IoT) network and introduces the existing Network Time Protocol (NTP). On the basis of this, we propose a relatively accurate time synchronization method, especially in heterogeneous mesh networks. Using this NTP, multiple time coordinators can be placed in a mesh network to find the delay error using the average delay time and the delay time of the time coordinator. Therefore, accurate time can be synchronized when implementing IoT, remote metering, and real-time media streaming using IoT mesh network.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.6
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• pp.161-167
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• 2010

Social individualized broadcasting increases rapidly in an environment that combines communication and broadcasting. Real-time individualized broadcasting is a service that is provided by multiple individuals to many and unspecified persons. In contrast, newly introduced individualized broadcasting service is a service that has not been experienced socially and culturally and therefore many problems are expected. The newly emerging real-time individualized broadcasting service may bring about various dysfunctions as well as desirable functions. Establishment of guideline and its implementation based in vulnerability analysis are necessary to prevent the expected dysfunctions and reinforce the desirable functions. Therefore, the purpose of this paper is to examine dysfunctions of the information-oriented society which threaten cyber-norms, cyber-morality, cyber-dangers, cyber-democracy, etc. at the level of social individualized broadcasting service and to propose appropriate guidelines. Through this paper, first, future changes of dysfunctions of the information-oriented society due to individualized broadcasting service can be forecast, and countermeasures and policy directions can be proposed. Second, Dysfunctions of ICT-based service that may emerge in individualized broadcasting service can be forecast and correct guideline can be prepared to reduce potential dangers and increase desirable functions of the service. This paper will analyze in various aspects the characteristics of a new media with the focus on individualized broadcasting service among the new ICT-integrated services, and forecast the appearance and aggravation of the dysfunctions and then draw the guideline.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.5
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• pp.45-53
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• 2014

This study investigated users' usage of mobile video service, users' perception and usage of mobile IPTV. The results show that 82.8% is using mobile video services and 33.6% of the entire respondents has the intention to use mobile IPTV with regards to future usage. They answered that 'various real-time broadcasting' and'mobile IPTV charges' were the major areas of considerations for mobile IPTV users. And we analyzed the most watching contents on mobile IPTV and the willingness to pay for one month. In addition, the main reasons for not using mobile IPTV were the charges for mobile IPTV. Based on these results, action plans for the promotion of mobile IPTV are proposed.