• ETRI Journal
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• v.39 no.4
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• pp.525-534
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• 2017

A hardware-acceleration architecture that separates virtual network functions (VNFs) and network control (called HSN) is proposed to solve the mismatch between the simple flow steering requirements and strong packet processing abilities of software-defined networking (SDN) forwarding elements (FEs) in SDN/network function virtualization (NFV) architecture, while improving the efficiency of NFV infrastructure and the performance of network-intensive functions. HSN makes full use of FEs and accelerates VNFs through two mechanisms: (1) separation of traffic steering and packet processing in the FEs; (2) separation of SDN and NFV control in the FEs. Our HSN prototype, built on NetFPGA-10G, demonstrates that the processing performance can be greatly improved with only a small modification of the traditional SDN/NFV architecture.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.4
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• pp.613-631
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• 2013

Cognitive radio (CR) is proposed as a key solution to improve spectral efficiency and overcome the spectrum scarcity. Spectrum sensing is an important task in each CR system with the aim of identifying the spectrum holes and using them for secondary user's (SU) communications. Several conventional methods for spectrum sensing have been proposed such as energy detection, matched filter detection, etc. However, the main limitation of these classical methods is that the CR network is not able to communicate with its own base station during the spectrum sensing period and thus a fraction of the available primary frame cannot be exploited for data transmission. The other limitation in conventional methods is that the SU data frames should be synchronized with the primary network data frames. To overcome the above limitations, here, we propose a spectrum sensing technique based on blind source separation (BSS) that does not need time synchronization between the primary network and the CR. Moreover, by using the proposed technique, the SU can maintain its transmission with the base station even during spectrum sensing and thus higher rates are achieved by the CR network. Simulation results indicate that the proposed method outperforms the accuracy of conventional BSS-based spectrum sensing techniques.

• ETRI Journal
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• v.38 no.1
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• pp.112-122
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• 2016

This paper presents a set of candidate regulatory requirements for TV band devices (TVBDs) in the Rep. of Korea. To guarantee the protection of incumbent services, especially digital TV (DTV) and wireless microphones, in TV frequency bands, we suggest minimum separation distances of TVBDs from the noise-limited contour according to incumbent users and TVBD types. This paper also deals with multiple sets of separation distances of a co-channel TVBD network from a DTV protected contour on the basis of the radio propagation characteristics of different geographic areas to make good use of TV white space (TVWS) and safely protect the DTV service. We present a low-power transmission mode of TVBDs and the relevant separation distances for small-cell deployment. The service coverage reduction ratio of a TVBD network is investigated in the presence of DTV interference in four geographic areas. The TVWS field verification results, conducted on the island of Jeju (Rep. of Korea), show that incumbent services operate well without harmful interference from neighboring TVBDs with the proposed separation distances.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.5
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• pp.609-614
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• 2009

In this paper, we have proposed a design for security network system passing through the non-security network which is commonly used for various networking services. Based on the security requirements which are assumed that the large classified data are bi-transmitted between a server and several terminals remotely located, some application methods of security techniques are suggested such as the network separation technique, the scale-down application technique of certification management system based on the PKI(Public Key Infrastructure), the double encryption application using the crypto-equipment and the asymmetric keys encryption algorithm, unrecoverable data deleting technique and system access control using USB device. It is expected that the application of this design technique for the security network causes to increase the efficiency of the existing network facilities and reduce the cost for developing and maintaining of new and traditional network security systems.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.209-212
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• 2001

We Propose a novel structure add/drop multiplexer based on an all-fiber Mach-Zehnder interferometer and fiber Bragg grating. In this structure, wavelength separation is achieved by adjusting the amount of the phase shift in the Mach-Zehnder interferometer. The proposed add/drop multiplexer drops a part of signal at a specific wavelength and transmit the remnant of the signal to the different node separated wavelength in WDM network.

• International Journal of Computer Science & Network Security
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• v.24 no.6
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• pp.49-58
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• 2024

This paper examines regularity and normality in soft separation axioms for soft bitopological ordered spaces and their relationships with other properties. The findings expand our understanding of bitopological ordered spaces. Previous research, such as Al-Shami's work [3], has established distinctions between separation axioms in topological ordered spaces, which are more effective in describing these spaces' properties.

• Journal of the Korea Convergence Society
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• v.11 no.10
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• pp.37-44
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• 2020

Due to the recent COVID 19 pandemic, public institutions are increasingly working from home. Working in public institutions is rapidly changing into a smart work environment where time and space constraints disappear. However, many public institutions currently lack a security model for an efficient smart work environment due to the physical network separation system that separates the Internet network and the business network. Therefore, in this paper, we describe the current limitations for implementing smart work in a physical network separation environment of public institutions, and propose a security model necessary for a work environment to supplement them. As a related study, explain SSL VPN and explain smart work business model through security model research of SDP (Software Defined Perimeter), RDP (Remote Desktop Protocol), and VDI (Virtual Desktop Infrastructure) to overcome the security limitations of SSL VPN. As a result, we intend to propose a security model for a smart work environment suitable for public institutions while complying with the physical network separation security guide.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.57.4-58
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• 2015

Thanks to high cadence monitoring and high photometric accuracy of Korea Microlensing Telescope Network (KMTNet), we expect the detection of many events caused by wide-separation planets and free-floating planets, which is not easy due to the short event duration. Thus, it is important to understand wide-separation planetary lensing events. Several studies on the wide-separation events have been reported, but events caused by wide-separation planetary systems with a moon have not yet been studied. In this paper, we study the properties of events caused by planetary systems where wide-separation planets host a moon. We also study the effect of a finite background source star on the moon feature in the wide planetary-lensing events.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.2
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• pp.31-37
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• 2015

Recently, mobile phones have become necessary tools for everyday life. In this study, a device that can serve as a separation between a touch panel and an LCD module in a mobile phone was devised for mass repair processes at a smaill business. We used a wire cutting method to separate the bonding plate area between the modules. The device is composed of DC motors and stepping motors that can deliver a precise cutting motion. The motor control system is connected by individual control modules to a CAN network. The developed device showed excellent performance at high temperature conditions.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.10a
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• pp.86-87
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• 1996

IPN (Interpenetrating Polymer Network) is a mixture of two or more crosslinked polymers with physically interlocked network structures between the component polymers. IPN can be classified as an alloy of thermosets and has the characteristics of thermosets such as the thermal resistance and chemical resistance and also has the characteristics of polymer alloys with enhanced impact resistance and amphoteric properties. The physical interlocking during the synthesis restricts the phase separation of the component polymer with chemical pinning process, thus the control of morphology is possible through variations of the reaction temperature and pressure, catalyst concentration and crosslinking agent concentration. Finely dispersed domain structure can be obtained through IPN synthesis of polymer components with gross immiscibility. In membrane applications, particularly for the separation of liquid mixtures, crosslinked polymer component with specific affinity to the permeate is needed. With the presence of the permeant-inert polymer component, the mechanical strength and the selectivity of the membranes are enhanced by restricting the swelling of the transporting polymer component networks.