• Neonatal Medicine
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• v.15 no.1
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• pp.105-110
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• 2008

Neonatal liver abscesses are rare, carry a high mortality rate, and are difficult to diagnose. The diagnosis of liver abscesses in the neonate cannot be established from the clinical presentation alone. Risk factors for liver abscesses in neonates are maternal infection, sepsis, umbilical venous catheterization, omphalitis, and necrotizing enterocolitis. In this report, we describe a preterm infant (32 weeks, 1,580 g) who presented with abdominal distension, respiratory difficulties, and a persistent inflammatory response in spite of broad spectrum antibiotic treatment; a large (6${\times}$5 cm) solitary pyogenic liver abscess was identified at 9 days of age. It appeared that the liver abscess had originated in the uterus and umbilical venous catheterization facilitated its spread. Percutaneous drainage under abdominal ultrasound guidance was performed and prolonged antibiotics were treated for 5 weeks, effecting a cure.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.9
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• pp.1658-1664
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• 2007

The popularity of OFDM systems is being increased because of high speed data transmission capability md the spectral efficiency characteristics. However, since OFDM systems are very sensitive to the Doppler spread, The interference among subcarriers and the total system noise can be increased seriously due to the degree of Doppler effects which can cause the orthogonality problems. Therefore, these Doppler effects were analyzed using the Doppler spectrum models by varying its parameters. Especially in this paper, The degree of system performance degradation was investigated for the OFDM systems applying the relatively simple transmit and receiver diversity. The degree of the system performance degradation depends on the specific diversity structures of transceiver systems. Here, the performances of OFDM systems with two antennas transceiver diversity were analyzed and compared with that of systems with only transmission diversity and without diversity as the Doppler characteristics varied.

• Journal of Microbiology and Biotechnology
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• v.32 no.6
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• pp.816-823
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• 2022

The rapid spread of superbugs leads to the escalation of infectious diseases, which threatens public health. Endolysins derived from bacteriophages are spotlighted as promising alternative antibiotics against multi-drug resistant bacteria. In this study, we isolated and characterized the novel Salmonella typhimurium phage PBST08. Bioinformatics analysis of the PBST08 genome revealed putative endolysin ST01 with a lysozyme-like domain. Since the lytic activity of the purified ST01 was minor, probably owing to the outer membrane, which blocks accessibility to peptidoglycan, antimicrobial peptide cecropin A (CecA) was fused to the N-terminus of ST01 to disrupt the outer membrane. The resulting CecA::ST01 has been shown to have increased bactericidal activity against gram-negative pathogens including Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, Escherichia coli, and Enterobacter cloacae and the most affected target was A. baumannii. In the presence of 0.25 µM CecA::ST01, A. baumannii ATCC 17978 strain was completely killed and CCARM 12026 strain was wiped out by 0.5 µM CecA::ST01, which is a clinical isolate of A. baumannii and resistant to multiple drugs including carbapenem. Moreover, the larvae of Galleria mellonella could be rescued up to 58% or 49% by the administration of CecA::ST01 upon infection by A. baumannii 17978 or CCARM 12026 strain. Finally, the antibacterial activity of CecA::ST01 was verified using 31 strains of five gram-negative pathogens by evaluation of minimal inhibitory concentration. Thus, the results indicate that a fusion of antimicrobial peptide to endolysin can enhance antibacterial activity and the spectrum of endolysin where multi-drug resistant gram-negative pathogens can be efficiently controlled.

• Journal of Information Science Theory and Practice
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• v.9 no.1
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• pp.1-23
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• 2021

This study introduces novel research using Practice Context Models supported by Knowledge Networks and Percolation Theory with the aim to contribute to knowledge management in Proof-of-Concept (PoC) activities. The authors envision this proposal as a potential instrument to identify network structures based on a percolation (propagation) threshold and to analyze the importance of nodes (e.g., practitioners, practices, competencies, movements, and scenarios) during the percolation of knowledge in PoC activities. After thirty months immersed in the natural PoC habitat, acting as observers and practitioners, and supported by an ethnographic exercise and a designer-research mindset, the authors identified the production of meaning in PoC activities occurring in a hermeneutic circle characterized by the presence of several knowledge networks; thus, discovering the 'natural knowledge' in PoC as a spectrum of cognitive development spread throughout its network, as each node could produce and disseminate certain knowledge that flows and influences other nodes. Therefore, this research presents the use of Practice Context Models 'connected' to Knowledge Networks and Percolation Theory as a potential and feasible proposal to be built using the attribution of values (weights) to the nodes (e.g., practitioners, practices, competencies, movements, scenarios, and also knowledge) in the context of PoC with the aim to allow the players (e.g., PoC practitioners) to have more flexibility in building alliances with other players (new nodes); that is, focusing on those nodes with higher value (focus on quality) in collaboration networks, i.e., alliances (connections) with the aim to contribute to knowledge management in the context of PoC.

• Journal of the Korea Society for Simulation
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• v.31 no.4
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• pp.11-22
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• 2022

Unlike a short-range, a long-range underwater acoustic communication(UWAC) uses low frequency signal and deep sound channel to minimize propagation loss. In this case, even though communication signals are modulated using a covert transmission technique such as spread spectrum, it is hard to conceal the existence of the signals. The unconcealed communication signal can be utilized as active sonar signal by enemy and presence of underwater vehicles may be exposed to the interceptor. Since it is very important to maintain stealthiness for underwater vehicles, the detection probability of friendly underwater vehicles should be considered when interceptor utilizes our long-range UWAC signal. In this paper, we modeled a long-range UWAC environment for analyzing the detection performance of underwater vehicles and proposed the region of interest(ROI) setup method and the measurement of detection performance. By computer simulations, we yielded parameters, analyzed the detection probability and the detection performance in ROI. The analysis results showed that the proposed detection performance analysis method for underwater vehicles could play an important role in the operation of long-range UWAC equipment.

• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.269-278
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• 2023

Antibiotics either kill or inhibit the growth of bacteria. However, antibiotic-resistant bacteria are difficult to treat with antibiotics. Infections caused by such bacteria often lead to severe diseases. Antibiotic resistance genes (ARG) can be horizontally transmitted across different bacterial species, necessitating a comprehensive understanding of how ARGs spread across various environments. In this study, we analyzed the plasmid sequences of 33 extended-spectrum beta-lactamases (ESBL) producing Escherichia coli isolated from pigs, farms, and their owners. We conducted an antibiotic susceptibility test (AST) with aztreonam and seven other antibiotics, as well as whole genome sequencing (WGS) of the strains using MinION. Our results demonstrated that the plasmids that did not harbor ARGs were mostly non-conjugative, whereas the plasmids that harbored ARGs were conjugative. The arrangement of these ARGs exhibited a pattern of organization featuring a series of ARG cassettes, some of which were identical across the isolates collected from different sources. Therefore, this study suggests that the sets of ARG cassettes on plasmids were mostly shared between pigs and their owners. Hence, enhanced surveillance of ARG should be implemented in farm environments to proactively mitigate the risk of antibiotic-resistant bacterial infections.

• Journal of Intelligence and Information Systems
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• v.17 no.2
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• pp.97-107
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• 2011

Nowadays there are a lot of issues about copyright infringement in the Internet world because the digital content on the network can be copied and delivered easily. Indeed the copied version has same quality with the original one. So, copyright owners and content provider want a powerful solution to protect their content. The popular one of the solutions was DRM (digital rights management) that is based on encryption technology and rights control. However, DRM-free service was launched after Steve Jobs who is CEO of Apple proposed a new music service paradigm without DRM, and the DRM is disappeared at the online music market. Even though the online music service decided to not equip the DRM solution, copyright owners and content providers are still searching a solution to protect their content. A solution to replace the DRM technology is digital audio watermarking technology which can embed copyright information into the music. In this paper, the author proposed a new audio watermarking algorithm with two approaches. First, the watermark information is generated by two dimensional barcode which has error correction code. So, the information can be recovered by itself if the errors fall into the range of the error tolerance. The other one is to use chirp sequence of CDMA (code division multiple access). These make the algorithm robust to the several malicious attacks. There are many 2D barcodes. Especially, QR code which is one of the matrix barcodes can express the information and the expression is freer than that of the other matrix barcodes. QR code has the square patterns with double at the three corners and these indicate the boundary of the symbol. This feature of the QR code is proper to express the watermark information. That is, because the QR code is 2D barcodes, nonlinear code and matrix code, it can be modulated to the spread spectrum and can be used for the watermarking algorithm. The proposed algorithm assigns the different spread spectrum sequences to the individual users respectively. In the case that the assigned code sequences are orthogonal, we can identify the watermark information of the individual user from an audio content. The algorithm used the Walsh code as an orthogonal code. The watermark information is rearranged to the 1D sequence from 2D barcode and modulated by the Walsh code. The modulated watermark information is embedded into the DCT (discrete cosine transform) domain of the original audio content. For the performance evaluation, I used 3 audio samples, "Amazing Grace", "Oh! Carol" and "Take me home country roads", The attacks for the robustness test were MP3 compression, echo attack, and sub woofer boost. The MP3 compression was performed by a tool of Cool Edit Pro 2.0. The specification of MP3 was CBR(Constant Bit Rate) 128kbps, 44,100Hz, and stereo. The echo attack had the echo with initial volume 70%, decay 75%, and delay 100msec. The sub woofer boost attack was a modification attack of low frequency part in the Fourier coefficients. The test results showed the proposed algorithm is robust to the attacks. In the MP3 attack, the strength of the watermark information is not affected, and then the watermark can be detected from all of the sample audios. In the sub woofer boost attack, the watermark was detected when the strength is 0.3. Also, in the case of echo attack, the watermark can be identified if the strength is greater and equal than 0.5.

• The KIPS Transactions:PartB
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• v.15B no.4
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• pp.307-314
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• 2008

This paper presents a new robust watermarking method for curves that uses informed-detection. To embed watermarks, the presented algorithm parameterizes a curve using the B-spline model and acquires the control points of the B-spline model. For these control points, 2D mesh are created by applying Delaunay triangulation and then the mesh spectral analysis is performed to calculate the mesh spectral coefficients where watermark messages are embedded in a spread spectrum way. The watermarked coefficients are inversely transformed to the coordinates of the control points and the watermarked curve is reconstructed by calculating B-spline model with the control points. To detect the embedded watermark, we apply curve matching algorithm using inflection points of curve. After curve registration, we calculate the difference between the original and watermarked mesh spectral coefficients with the same process for embedding. By calculating correlation coefficients between the detected and candidate watermark, we decide which watermark was embedded. The experimental results prove the proposed scheme is more robust than previous watermarking schemes against print-scan process as well as geometrical distortions.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.3
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• pp.402-413
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• 2001

Food safety is a term broadly applied to food quality that may adversely affect human health. These include zoonotic diseases and acute and chronic effects of ingesting natural and human-made xenobiotics. There are two major areas of concern over the presence of residues of antibiotics in animal-derived foodstuffs with regard to human health. The first is allergic reactions. Some antibiotics, such as penicillins can evoke allergic reactions even though small amounts of them are ingested or exposed by parenteral routes. The second is development of antibiotic resistance in gut bacteria of human. Recently multi-resistant pneumococcal, glycopeptide-resistant enterococci and gram negative bacteria with extended-spectrum $\beta$-lactamases have spread all over the world, and are now a serious therapeutic problem in human. Although it is evident that drugs are required in the efficient production of meat, milk and eggs, their indiscriminate use should never be substituted for hygienic management of farm. Drug should be used only when they are required. In addition to veterinary drugs, environmental contaminants that were contaminated in feed, water and air can make residues in animal products. Mycotoxins, heavy metals, pesticides, herbicides and other chemicals derived from industries can be harmful both to animal and human health. Most of organic contaminants, such as dioxin, PCBs and DDT, and metals are persistent in environment and biological organisms and can be accumulated in fat and hard tissues. Some of them are suspected to have endocrine disrupting, carcinogenic, teratogenic, immunodepressive and nervous effects. The governmental agencies concerned make efforts to prevent residue problems; approval of drugs including withdrawal times of each preparation of drugs, establishment of tolerances, guidelines regarding drug use and sanitation enforcement of livestock products. National residue program is conducted to audit the status of the chemical residues in foods. Recently HACCP has been introduced to promote food safety from farm to table by reducing hazardous biological, chemical and physical factors. Animal Production Food Safety Program, Quality Assurance Programs, Food Animal Residue Avoidance Databank are para- or non-governmental activities ensuring food safety. This topic will cover classification and usage or sources of chemical residues, their adverse effects, and chemical residue status of some countries. Issues are expanded to residue detection methodologies, toxicological and pharmacokinetic backgrounds of MRL and withdrawal time establishments, and the importance of non-governmental activities with regard to reducing chemical residues in food.

• Journal of Periodontal and Implant Science
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• v.30 no.3
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• pp.661-676
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• 2000

Gingivitis and periodontitis are infectious diseases in that microorganisms are the primary extrinsic cause of the diseases. the occurrence of gingivitis has been associated clearly with the presence of microorganisms at the disease site, and the histologic nature of the tissue involved is indicative of an inflammatory response induced by microorganisms. additional evidence for the microbial etiology of periodontal disease is that numerous antimicrobial agents are effective in reducing plaque accumulation and periodontal diseases. the purpose of this article is to analyze the antimicrobial effects of Pulsatilla koreana. Well-dried Pulsatilla koreana purchased from herbs distributor was ground and extracted into methanol(MeOH), ethylacetate(EtoAc), chlorform($CHCl_3$) and Butyl alcohol(BuOH). we have then applied each solution to the bacteria samples(Bacteroides forsythus, Streptococcus mutans, Streptococcus sanguis, Porphylomonas gingivalis, Actinobacillus actinomycetemcomitans, Eikenella corrodens, Prevotella intermedia, Actinomyces viscosus, Prevotella nigrescens , Rothia dentocariosa, Fusobacterium nucleatum, Pseudomonas aeruginosa, Staphylococcus aureus) collected from several organizations. To conduct susceptibility test(Kirby-Bauer method), plate contained each periodontopathic bacteria is spread extracted into methanol(MeOH), ethylacetate(EtoAc), chlorform($CHCl_3$) and Butyl alcohol(BuOH) and to measure the minimum inhibition concentration(MIC) of the bacteria against the solutions to ultimately determine antimicrobial effects of the solutions, insert bacteria sample into $20{\mu\ell}/{m\ell}$, $10{\mu\ell}/{m\ell}$, $5{\mu\ell}/{m\ell}$, $2.5{\mu\ell}/{m\ell}$ of each solution and control group(not contained solution) 1. Solution extracted into methanol did not show clear zone against all bacteria samples. Only P.nigrescens, S. mutans and S. sanguis in solution extracted into ethylacetate, S. mutans and S. anguis in solutions extracted into chlorform and Butyl alcohol showed clear zone against all bacteria samples. Solution extracted into Butyl alcohol showed clear zone against 13 types of bacteria, excluding P. gingivalis. 2. In Solution extracted into methanol, the bacteria samples grew in the highest concentrated plate, showing minimal variation from control group. 3. In Solution extracted into Butyl alcohol, S. aureus, P. intermedia, E. corrodens, A. actinomycetemcomitans, B. forsythus, P. gingivalis et al. showed decreased growth in the highest concentrated plate. P. auruginosa, R. dentocariosa, A. viscosus, P. nigrescens, S. mutans et al. showed decreased growth at MIC $20{\mu\ell}/{m\ell}$ and S. sanguis showed decreased growth at MIC $10{\mu\ell}/{m\ell}$. 4. By analyzing the MIC level through considering the results from Kirby-Bauer method, Solution extracted into methanol did not reveal any antimicrobial effects and Solution extracted into Butyl alcohol showed the highest antimicrobial effects In conclusion, it can be used the extracts of Pulsatilla koreana as wide spectrum antimicrobial agent.