• Journal of the Korea Society of Computer and Information
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• v.14 no.9
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• pp.47-54
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• 2009

Malicious codes, which are spread through WWW are now evolved with various hacking technologies However, detecting technologies for them are seemingly not able to keep up with the improvement of hacking and newly generated malicious codes. In this paper, we define the requirements of detecting systems based on the analysis of malicious codes and their spreading characteristics, and propose an improved detection scheme which monitors HTTP Outbound traffic and detects spreading malicious codes in real time. Our proposed scheme sets up signatures in IDS with confirmed HTML tags and Java scripts which spread malicious codes. Through the verification analysis under the real-attacked environment, we show that our scheme is superior to the existing schemes in satisfying the defined requirements and has a higher detection rate for malicious codes.

• Korean Journal of Agricultural Science
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• v.39 no.3
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• pp.421-425
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• 2012

The objective of this study was to improve the detection limit of rapid detection kit for Salmonella Typhimurium by image analysis system. The rapid detection kit was comprised of four elements: sample pad, conjugate pad, nitrocellulose pad and absorbent pad. Gold nanoparticle and Salmonella antibody were used as a tag and a receptor. Salmonella antibody and goat rabbit IgG antibody were used as test and control lines on nitrocellulose membrane. The color intensity of test line began to increase from $10^5CFU/mL$ of Salmonella sample. A multiple linear regression analysis was employed to explain the relationship between predicted and measured number of Salmonella cells. The developed model could successfully predict the cell number of Salmonella with validation against extra-experimental result.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.2
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• pp.493-504
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• 2017

Recently, tremendous amounts of unstructured text data that is distributed through news, blogs, and social media has gained much attention from many researchers and practitioners as this data contains abundant information about various consumers' opinions. However, as the usefulness of text data is increasing, more and more attempts to gain profits by distorting text data maliciously or nonmaliciously are also increasing. This increase in spam text data not only burdens users who want to obtain useful information with a large amount of inappropriate information, but also damages the reliability of information and information providers. Therefore, efforts must be made to improve the reliability of information and the quality of analysis results by detecting and removing spam data in advance. For this purpose, many studies to detect spam have been actively conducted in areas such as opinion spam detection, spam e-mail detection, and web spam detection. In this study, we introduce core concepts and current research trends of spam detection and propose a methodology to detect the spam tag of a blog as one of the challenging attempts to improve the reliability of blog information.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.321-325
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• 2009

The detection process of defective tags in most of Korean domestic RFID manufacturing companies is handled or treated by on-hand processing after the job of chip bonding, so it has been requesting to reduce the time and cost for manufacturing of RFID tags. Therefore, in this paper, we design and implement the system to perform the functionality of detection of defective tags after the process of chip bonding, and so provide the basis of a related software to establish the foundation of a automation system for the detection of defected RFID tags which is requested in the related Korean domestic industrial field. The developed system in this paper shows the enhancement of 700% in processing speed and 100% in detection rate of defective tags, comparing to the method of on-hand processing.

• Journal of Microbiology and Biotechnology
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• v.33 no.7
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• pp.964-972
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• 2023

Bacteriophage endolysins are peptidoglycan hydrolases composed of cell binding domain (CBD) and an enzymatically active domain. A phage endolysin CBD can be used for detecting bacteria owing to its high specificity and sensitivity toward the bacterial cell wall. We aimed to develop a method for detection of Enterococcus faecalis using an endolysin CBD. The gene encoding the CBD of ECP3 phage endolysin was cloned into the Escherichia coli expression vector pET21a. A recombinant protein with a C-terminal 6-His-tag (CBD) was expressed and purified using a His-trap column. CBD was adsorbed onto epoxy magnetic beads (eMBs). The bacterial species specificity and sensitivity of bacterial binding to CBD-eMB complexes were determined using the bacterial colony counting from the magnetic separations after the binding reaction between bacteria and CBD-eMB complexes. E. faecalis could bind to CBD-eMB complexes, but other bacteria (such as Enterococcus faecium, Staphylococcus aureus, Escherichia coli, Acinetobacter baumannii, Streptococcus mutans, and Porphyromonas gingivalis) could not. E. faecalis cells were fixed onto CBD-eMB complexes within 1 h, and >78% of viable E. faecalis cells were recovered. The E. faecalis recovery ratio was not affected by the other bacterial species. The detection limit of the CBD-eMB complex for E. faecalis was >17 CFU/ml. We developed a simple method for the specific detection of E. faecalis using bacteriophage endolysin CBD and MBs. This is the first study to determine that the C-terminal region of ECP3 phage endolysin is a highly specific binding site for E. faecalis among other bacterial species.

• Journal of Microbiology and Biotechnology
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• v.16 no.10
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• pp.1583-1590
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• 2006

T4 endonuclease V (T4 endo V) [EC 3. 1. 25. 1], found in bacteriophage T4, is responsible for excision repair of damaged DNA. The enzyme possesses two activities: a cyclobutane pyrimidine dimer DNA glycosylase (CPD glycosylase) and an apyrimidic/apurinic endonuclease (AP lyase). T4 denV (414 bp cDNA) encoding T4 en do V (138 amino acid) was synthesized and expressed using either an expression vector, pTriEx-4, in E. coli or a baculovirus AcNPV vector, pBacPAK8, in insect cells. The recombinant His-Tag/T4 endo V (rHis-Tag/T4 endo V) protein expressed from bacteria was purified using one-step affinity chromatography with a HiTrap Chelating HP column and used to make rabbit anti-His-Tag/T4 endo V polyclonal antibody for detection of recombinant T4 endo V (rT4 endo V) expressed in insect cells. In the meantime, the recombinant baculovirus was obtained by cotransfection of BacPAK6 viral DNA and pBP/T4 endo V in Spodoptera frugiperda (Sf21) insect cells, and used to infect Sf21 cells to overexpress T4 endo V protein. The level of rT4 endo V protein expressed in Sf21 cells was optimized by varying the virus titers and time course of infection. The optimal expression condition was set as follows; infection of the cells at a MOI of 10 and harvest at 96 h post-infection. Under these conditions, we estimated the amount of rT4 endo V produced in the baculovirus expression vector system to be 125 mg/l. The rT4 endo V was purified to homogeneity by a rapid procedure, consisting of ion-exchange, affinity, and reversed phase chromatographies, based on FPLC. The rT4 endo V positively reacted to an antiserum made against rHis-Tag/T4 endo V and showed a residual nicking activity against CPD-containing DNA caused by UV. This is the first report to have T4 endo V expressed in an insect system to exclude the toxic effect of a bacterial expression system, retaining enzymatic activity.

• Journal of the Korea Safety Management & Science
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• v.17 no.2
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• pp.129-137
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• 2015

This study is in regard to the gas detection system and gas detection method utilizing smart phone. This study includes; 1) the sensor module attached to the smart phone to detect and measure flammable gas or toxic gas; and 2) gas detection APP which is installed inside the smart phone and recognizes the user information and location information automatically by reading RFID tag indicating the user or the location to detect gas through the contact area where RFID and blue tooth reader is installed inside of the above mentioned smart phone, and then measures the combustible gas or toxic gas by operating above mentioned sensor module and obtains the data thus measured, and above mentioned smart phone is characterized by its transmission of the above mentioned user information, location information and measured data which are obtained by above mentioned gas detecting APP to operation server via communication network. With this, reliability for the location detecting gas by the user, the result of the measurement, etc. can be secured. Furthermore, this provides the effect of preventing artificial manipulation at the time of input which is associated with the identification of the user to be measured by utilizing removable sensor module and application or the mistake resulted from wrong input by the user. In addition, by transmitting the measured data from the sensor module carrying out gas detection to operation server, this provides the effect of making it possible to process the data thus collected to a specialized data for combustible gas or toxic gas.

• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.509-516
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• 2003

A model system for the immnunochemical detection of Escherichia coli O157:H7 using a combined immunomagnetic separation (IMS) and test-strip liposome immunoassay (LIA) procedure was developed. Immunomagnetic beads coated with anti-E. coli O157 IgG antibodies were used to separate the E. coli O157 (including the H7 serotype) from culture. Immunoliposomes, whose surface was conjugated to goat anti-E. coli O157:H7 IgG and which encapsulated the marker dye, sulforhodamine B, were used as a detection label. The test strip, onto which antibodies to goat IgG were immobilized, was the immunosensor capturing immunoliposomes that did not bind to E. coli O157:H7 on the immunomagnetic bead-E. coli O157:H7 complexes. In experiments, pure cell culture suspensions of $10^5 E.$ coli O157:H7 organisms per ml produced a measurable signal inhibition, whereas a weak yet detectable signal inhibition occurred with $10^3CFU/ml$. The inhibition signals increased, when the incubation time for IMS was extended to 90 min and higher IgG-tag density (0.4mol%) was used on the liposomes. With 0.2 and 0.4mol% IgG-tagged liposomes, the IMS-LIA procedure showed more improved signal inhibitions than those of a direct (no IMS) LIA. The combined assay, which measures the instantaneous signal from immunoliposomes, can be completed within 90 min, making it significantly faster than conventional plating methods and enzyme-linked immunosorbent assay (ELISA). Accordingly, it is quite feasible to use the combined immunoassay format of IMS and dye-loaded immunoliposomes for the detection of E. coli O157:H7.

• Journal of Biosystems Engineering
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• v.36 no.2
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• pp.140-146
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• 2011

This study was performed to develop a rapid test kit for pathogenic Salmonella in various samples. The rapid detection kit has been fabricated based on nitrocellulose lateral-flow strip. Colloidal gold and biotin conjugated Salmonella antibodies were used as a tag and a receptor, respectively. Manually spotted Salmonella antibody and Neutravidin on nitrocellulose membrane were used as test and control lines, respectively. Feasibility of the rapid kit to detect Salmonella typhimurium in samples were evaluated. The intensity of the color of the test line started to increase with the samples in which higher concentration of the cells were contained. The sensitivity of the sensor was $10^6$ cfu/mL Salmonella spiked in PBS. Also, the rapid test kit could detect $10^6$ cfu/mL of Salmonella in chicken meat extract.

• The Plant Pathology Journal
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• v.26 no.1
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• pp.25-31
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• 2010

Papaya ringspot virus (PRSV) causes the most widespread and devastating disease in papaya. Isolates of PRSV originating from different geographical regions in south India were collected and maintained on natural host papaya. The entire coat protein (CP) gene of Papaya ringspot virus-P biotype (PRSV-P) was amplified by RTPCR. The amplicon was inserted into pGEM-T vector, sequenced and sub cloned into a bacterial expression vector pRSET-A using a directional cloning strategy. The PRSV coat protein was over-expressed as a fusion protein in Escherichia coli. SDS-PAGE gel revealed that CP expressed as a ~40 kDa protein. The recombinant coat protein (rCP) fused with 6x His-tag was purified from E.coli using Ni-NTA resin. The antigenicity of the fusion protein was determined by western blot analysis using antibodies raised against purified PRSV. The purified rCP was used as an antigen to produce high titer PRSV specific polyclonal antiserum. The resulting antiserum was used to develop an immunocapture reverse transcription-polymerase chain reaction (IC-RT-PCR) assay and compared its sensitivity levels with ELISA based assays for detection of PRSV isolates. IC-RT-PCR was shown to be the most sensitive test followed by dot-blot immunobinding assay (DBIA) and plate trapped ELISA.