• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.1
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• pp.291-304
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• 2019

This paper proposes a dynamic-tiling-based bandwidth-efficient (DTBE) virtual reality (VR) streaming scheme. We consider 360-degree VR contents with multiple view points such as the front, back, upper, and bottom sides. At a given time, the focus of a client is always bound to a certain view among multiple view points. By utilizing this perspective, under our proposed scheme, tiles with high encoding rates are selectively assigned to the focused view where multiple view points consist of multiple tiles with different encoding rates. The other tiles with low encoding rates are assigned to the remaining view points. Furthermore, for reducing view adaptation delay, we design a novel rapid view adaptation mechanism that selectively delivers an I-frame during view point updates by using frame indexing. We implement the proposed scheme on a commercial VR test bed where we adopt the MPEG media transport (MMT) standard with high-efficiency video coding (HEVC) tile modes. The measurement-based experiments show that the proposed scheme achieves an average data usage reduction of almost 65.2% as well as average view adaptation delay reduction of almost 57.7%.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2000.08a
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• pp.49-52
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• 2000

In this paper we have developed an image security system based on Internet Web in order to overcome the problem of existing systems that use the dedicated network. The developed system resolves the safety problem of the centralized control model by adapting the distributed control model based on Web, and has the functions of remote control and automatic monitoring for grouped multiple sites on Web browser. And the system can operate various computers or operating system because it's operating software was designed by the concepts of Java Virtual Machine and Virtual Instrument. Also, our system has not need of additional cost for network construction by using Internet and can greatly improve the managemental efficiency of system because the maintenance and publishing of software updates can be performed through Web Server.

• Journal of the Korea Society of Computer and Information
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• v.27 no.12
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• pp.197-207
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• 2022

The Naval Combat System operates in multiple software components for efficient functional processing. Data transmission and reception between components is performed in real time using DDS(Data Distribution Service). Reliable Post-Analysis requires the collection of all DDS messages. However, Software workload and development costs increase because common functions for all messages must be developed directly. In the paper, We propose an improved Post-Analysis based on the Feature Model and a new development system using it. Functions for the modified message were applied as variable domains of the Feature Model. When Build Center updates Post-Analysis, it automatically processes all software tasks associated with Post-Analysis. The proposed development system simplified the overall work procedure, and work time was significantly reduced compared to the existing development system.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.69.4-70
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• 2018

KAOS30 is an automatic observing software for the wide-field 10-inch telescope as a piggyback system on the 30-inch telescope at the McDonald Observatory in Texas, US. The software has four packages in terms of functionality and is divided into communication with Telescope Control System (TCS), controlling of CCD camera and filter wheel, controlling of focuser, and script for automation observing. Each interconnect of those are based on exe-exe communication. The advantage of this distinction is that each package can be independently maintained for further updates. KAOS30 has an integrated control library that combines function library connecting each device and package. This ensures that the software can extensible interface because all packages are access to the control devices independently. Also, the library includes the ASCOM driver platform. ASCOM is a standard general purpose library that supports Application Programming Interface (API) of astronomical devices. We present the software architecture of KAOS30, and structure of interfacing between hardware and package or package and package.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.2
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• pp.133-138
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• 2011

In IP-based wireless sensor networks (WSNs), it might be necessary to distribute application updates to the sensor nodes in order to fix bugs or add new functionality. However, physical access to nodes is in many cases extremely limited following deployment. Therefore, network reprogramming protocols have recently emerged as a way to distribute application updates without requiring physical access to sensor nodes. In order to solve the network reprogramming problem over the air interface, this thesis presents a new scheme for new update code propagation using fragmentation scheme and network coding. The proposed code propagation method roughly shows reduced performance improvement in terms of the number of data exchange compared with the previously proposed pipelining scheme. Further, It is shows enhanced reliability for update code propagation and reduced overhead in terms of the number of data exchange. As a result, we can efficiently perform the software update from the viewpoint of speed, energy, and network congestion when the proposed code propagation system is applied. In addition, the proposed system solves overhearing problems of network coding such as the loss of original messages and decoding error using the predefined message. Therefore, our system allows a software update system to exchange reliable data in wireless sensor networks.

• Journal of the Institute of Convergence Signal Processing
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• v.1 no.1
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• pp.74-81
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• 2000

In this paper we have developed an image security system based on Internet Web in order to overcome the problem of existing systems that use the dedicated network. The developed system resolves the safety problem of the centralized control model by adapting the distributed control model based on Web, and has the functions of remote control and automatic monitoring for grouped multiple sites on remote Web browser. And the system can operate various computers or operating system because it' s operating software was designed by the concepts of Java Virtual Machine and Virtual Instrument. Also, our system has not need of additional cost for network construction by using Internet and can greatly improve the managemental efficiency of system because the maintenance and publishing of software updates can be performed through Web Server.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.6
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• pp.1369-1374
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• 2014

In case of APT attacks, the update server is being used as a means of dissemination, the update program is running malicious code or data in applications such as anti-virus signature is vulnerable to manipulation, SW Update threat identification and prevention measures are urgently required. This paper presents a natiional and international SW update structure, update process exploits and response measures to examine, Through the extraction/analysis of a domestic famous SW update log, we are willing to select the necessary component of the normal program update to identify a white list.

• Journal of The Korean Astronomical Society
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• v.52 no.5
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• pp.207-216
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• 2019

In this paper we introduce a software package, the Very long baseline interferometry Network SIMulator (VNSIM), which provides an integrated platform assisting radio astronomers to design Very Long Baseline Interferometry (VLBI) experiments and evaluate the network performance, with a user-friendly interface. Though VNSIM is primarily motivated by the East Asia VLBI Network, it can also be used for other VLBI networks and generic interferometers. The software package not only integrates the functionality of plotting (u, v) coverage, scheduling the observation, and displaying the dirty and CLEAN images, but also adds new features including sensitivity calculations for a given VLBI network. VNSIM provides flexible interactions on both command line and graphical user interface and offers friendly support for log reports and database management. Multi-processing acceleration is also supported, enabling users to handle large survey data. To facilitate future developments and updates, all simulation functions are encapsulated in separate Python modules, allowing independent invoking and testing. In order to verify the performance of VNSIM, we performed simulations and compared the results with other simulation tools, showing good agreement.

• Journal of Multimedia Information System
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• v.7 no.3
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• pp.221-230
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• 2020

Used optimization techniques as solution for mobile network have been implemented as a reference systems for various applications against fading and signals perturbation, in addition each transition to 5th generation telecommunication standards require a deep studies in order to park an applied instantaneous process. The paper describes a preliminary planning and a careful preparation to update both subscriber radio access network as well as data transmission network this approach conducts to make network resource updates invisible for customers and with minimal costs for mobile operators basically in terms of delay. In addition, network operators transit to mobile networks, multimedia services efficient delivery are considered the challenging application and the most promising for mobile network operators today, this work conduct to optimize video consumption of mobile users which are exponentially increasing. The interference is a complex phenomenon in mobile radio telecommunication system, and a mobile phone can be a source of interference to another one. Actual advances in technology necessitate the need for the complicated software solution that can take several unexpected phenomena in consideration to rise to a level higher than ever. The capability needs today require the use of Drive test which is used to take the performance of network in the field by using a special software called TEMS investigation, it have been implemented as standalone systems for various applications. The paper focuses on considering as the best technical for optimization of mobile networks, analysis and processing of signal, a Drive Test is the method used to take the performance of network in the field by using a special software called TEMS investigation. Most used in the world, this software is reputed to detect and analyze many problems of mobile network between the mobile phone and the transmitter: BTS in case of GSM and Node B for UMTS. An example of that is interference in radio communication. It exists permanently and it degrades considerably the quality of received signal when it exceeds certain levels.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.11
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• pp.471-478
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• 2014

Database replication is utilized to increase credibility, availability and prevent overload of distributed databases. Two models currently exist for replication - Master/Slave and Multi-Master. Since the Multi-Master model has problems of increasing complexity and costs to interface among multiple databases for updates and inserts, the Master/Slave model is more appropriate when frequent data inserts and updates are required. However, Master/Slave model also has a problem of not having exact criteria when systems choose to connect between Master and Slave for transactions. Therefore, this research suggests a routing algorithm based on AOP (Aspect Oriented Programming) in the Master/Slave database model. The algorithm classifies applications as cross-cutting concerns based on AOP, modularizes each concern, and routes transactions among Master and Slave databases. This paper evaluates stability and performance of the suggested algorithm through integration tests based on scenarios.