• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.1
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• pp.1-5
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• 2017

This study investigated the mechanical tearing of a cell membrane using a nanostructured alumina filter for easy and quick mechanical cell disruption. Nanostructured alumina filters were prepared by a multi-step aluminum anodizing process and nanopore etching process. Six different types of nanostructures were formed on the surface of the nanoporous alumina filters to compare the mechanical cell disruption characteristics according to the shape of the nanostructure. The prepared alumina filter was assembled in a commercial filter holder, and then, NIH3T3 fibroblast cells in a buffer solution were passed through the nanostructured alumina filter at a constant pressure. By measuring the concentration of proteins and DNA, the characteristics of mechanical cell disruption of the nanostructured alumina filter were investigated.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.7
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• pp.1854-1873
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• 2012

Owing to its simplicity and flexibility, the session initiation protocol (SIP) has been widely adopted as a major session-management protocol for Internet telephony or Voice-over IP (VoIP) services. However, SIP has faced various types of security threats. Call-disruption attacks are some of the most severe threats they face, and can greatly inconvenience consumers. In this paper, we analyze such SIP call-disruption attacks, and propose a method for detecting and counteracting them by extending the SIP INFO method with authentication. Using the proposed method, both the target user and the SIP server can detect the existence of a call-disruption attack on a user and counteract the attack. We demonstrate the effectiveness of the proposed method from the viewpoint of computational complexity by configuring a test-bed with an Asterisk SIP proxy server and an SIP performance (SIPp) emulator.

• Journal of Korea Multimedia Society
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• v.3 no.3
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• pp.280-289
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• 2000

This paper presents an efficient method to provide seamless communication in mobile wireless networks. The goal of seamless communication is to provide disruption free service to a mobile user. A disruption in service could occur due to active handoffs. There are many user applications that do not require a total guarantee for disruption free service but would also not tolerate very frequent disruptions. This paper proposes an extended staggered multicast that provides a probabilistic guarantee for disruption free service. The proposed multicast forecasts the direction and velocity for a mobile host. It is possible that data packets for a mobile host are multicasted to not all neighbor cells but a par\ulcorner of neighbor cells those the mobile host will be handoff potentially on the basis of these information. Therefore, the extended staggered multicast significantly reduces the static network bandwidth usage also provides a probabilistic guarantee for disruption free service.

• KSBB Journal
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• v.26 no.4
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• pp.305-310
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• 2011

This study was carried out to establish the optimum condition of cell disruption with a sonicator for the detection of the spore, Bacillus anthracis ${\Delta}$-sterne for the purpose of developing automatic fluorometer. The efficiency of sonication on the ${\Delta}$-sterne spore disruption was very weak. The ${\Delta}$-sterne spore with zirconia bead showed greater disruption than the ${\Delta}$-sterne spore alone when sonificated. The volumn of the zirconia bead added in the spore solution has little effect on the disruption efficiency. The detection limit of the ${\Delta}$-sterne spore with zirconia bead and the ${\Delta}$-sterne spore alone was $10^6$ CFU/mL and $5{\times}10^7$ CFU/mL respectively, when sample was sonicated for 20 seconds with a sonicator probe of 13 mm diameter.

• Journal of Korean Society for Quality Management
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• v.35 no.4
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• pp.159-165
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• 2007

Using statistical methods a change-point analysis of oil supply disruption is conducted. The statistical distribution of oil supply disruption is a weibull distribution. The detection of the change-point is applied to Bayesian method and weibull parameters are estimated through Markov chain monte carlo and parameter approach. The statistical approaches to the estimation for the change-point and weibull parameters is implemented with the sets of simulated and real data with small sizes of samples.

• The KIPS Transactions:PartC
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• v.16C no.4
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• pp.521-526
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• 2009

Disruption/Delay Tolerant Network(DTN) is a technology for interconnecting partitioned networks. These days, DTN, especially routing in DTN, draws significant attention from the networking community. In this paper, we investigate DTN routing strategies for highly partitioned ad hoc networks where Unmanned Aerial Vehicles (UAVs) perform store-carry-forward functionality for improved network connectivity. Also we investigate UAV trajectory control mechanisms via simulation studies.

• Journal of the Korean Operations Research and Management Science Society
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• v.42 no.2
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• pp.19-34
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• 2017

In this study, we develop an optimal sourcing strategy considering compensation orders to mitigate the supply chain disruption risks. We considered two-echelon supply chain consisting of a single buyer and multiple suppliers who have fixed transaction cost and probabilistic disruption risks. Under this setting, we provide the joint optimization method to determine the number of suppliers and the order quantities. Through numerical examples, we provide managerial implications on the sourcing strategy by investigating changes in the order quantities and the number of suppliers due to the degree of supply chain disruption risks.

• BMB Reports
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• v.35 no.4
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• pp.428-431
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• 2002

The often-encountered problem of disrupting bacteria for the purpose of extracting soluble protein has generated various methods. Many require specialized equipment. Very often, especially during preliminary studies, investigators need a simple, fast, and inexpensive method for cell disruption that preserves biological activity. This paper compares some simple and inexpensive methods for cell disruption, such as bead-vortexing, freesing-thawing, French pressing, and sonication. It also provides some tips to increase protein yield and preserve biological activity. If performed under optimal conditions, bead-vortexing gives protein yields that are comparable to French pressing and sonication. It also preserves the activities of labile enzymes and releases periplasmic enzymes. Vortexing with glass beads appears to be the simplest method for cell disruption.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.5
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• pp.327-331
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• 2000

The application of LFH-PCR(long flanking homology region-PCR) for Bacillus subtilis gene disruption is presented. Without plasmid- or phage-vector construction, only by PCR, based on a DNA sequence retrieved from B. subtilis genome data base, kanamycin resistance gene was inserted into two genes of B. subtilis involved in sporulation, spoIIIE and spoIIIG. The effect of gene disruption on subtilisin expression was examined and the sporulation frequency of two mutants was compared to that of the host strain. For this purpose, only 2 or 3 rounds of PCR were required with 4 primers. We first demonstrated the possibility of LFH-PCR for rapid gene disruption to characterize an unknown functional gene of B. subtilis or other prokaryote in the genomic era.

• Journal of Microbiology and Biotechnology
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• v.16 no.9
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• pp.1472-1476
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• 2006

Previous study demonstrated that the restriction barrier of Streptomyces griseus is almost completely bypassed by the Streptomyces-E. coli shuttle vectors passed through the E. coli GM161 strain and methylated with AluI and HpaII methyltransferases. The same DNA methylation of the genomic DNA fragments cloned the nonreplicative vectors generated integrative transformation and gene disruption of their chromosomal counterparts at high efficiencies in S. griseus. This result indicated that the efficiency of gene disruption depends on the efficient transfer of the incoming DNA into bacterial hosts.