• Journal of Biomedical Engineering Research
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• v.36 no.5
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• pp.169-176
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• 2015

Implantable closed-loop epilepsy controllers require ideally both accurate epileptic seizure detection and low power consumption. On-chip oscillators can be used in implantable devices because they consume less power than other oscillators such as crystal oscillators. In this study, we investigated the tolerable error range of a lower power on-chip oscillator without losing the accuracy of seizure detection. We used 24 ictal and 14 interictal intracranial electroencephalographic segments recorded from epilepsy surgery patients. The performance variations with respect to oscillator frequency errors were estimated in terms of specificity, modified sensitivity, and detection timing difference of seizure onset using Generic Osorio Frei Algorithm. The frequency errors of on-chip oscillators were set at ${\pm}10%$ as the worst case. Our results showed that an oscillator error of ${\pm}10%$ affected both specificity and modified sensitivity by less than 3%. In addition, seizure onsets were detected with errors earlier or later than without errors and the average detection timing difference varied within less than 0.5 s range. The results suggest that on-chip oscillators could be useful for low-power implantable devices without error compensation circuitry requiring significant additional power. These findings could help the design of closed-loop systems with a seizure detector and automated stimulators for intractable epilepsy patients.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.5
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• pp.417-423
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• 2017

This paper intend to implement monitoring systems for individual customized diagnostics to maintain ongoing disease management to promote human health. Analyze the threshold of a measured biological signal using a number of measuring sensors. Performance assessment revealed that the SVM algorithm for bio-signal analysis showed an average error rate of 2 %. The accuracy of the classification is 97.2%, and reduced the maximum of 19.2% of the storage space when you split the window into 5,000 pieces. Out of the total 5,000 bio-signals, 84 results showed that results from the system were differently the results of the expert's diagnosis and showed about 98 % accuracy. However, the results of the monitoring system did not occur when the results of the monitoring system were lower than that of experts. And About 98% accuracy was shown.

• Journal of the Korean Society of Safety
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• v.27 no.1
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• pp.1-6
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• 2012

In crowded subway stations indoor air quality (IAQ) is a key factor for ensuring the safety and health of passengers. Since physical variables that describing IAQ such as the concentration of particulate, $CO_2$, VOCs and biological agents need to be closely monitored and controlled in multiple locations within subway stations and in remote sites, concept of web-based monitoring and control network using both wireless and wired media needs to be implemented. Connecting remote wireless sensor network and device (LonWorks) networks to the IP network based on the concept of VDN can provide a powerful, integrated, distributed monitoring and control performance. In this study, performance of wireless and wired network in VDN for monitoring and control of IAQ in subway stations is evaluated. Specifically, delay induced in wireless and wired networks, and data transmission rate are evaluated. A key parameter is identified in assuring safety and health of passengers in subway stations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.11
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• pp.5276-5298
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• 2019

Internet of Things (IoT) based sensor networks have gained unprecedented popularity in recent years. With the exponential explosion of the objects (sensors and mobiles), the bandwidth and the speed of data transmission are dwarfed by the anticipated emergence of IoT. In this paper, we propose a novel heterogeneous IoT model integrated the power line communication (PLC) and WiFi network to increase the network capacity and cope with the rapid growth of the objects. We firstly propose the mean transmission delay calculation algorithm based the 3D Markov chain according to the multi-priority of the objects. Then, the attractor selection algorithm, which is based on the adaptive behavior of the biological system, is exploited. The combined the 3D Markov chain and the attractor selection model, named MASM, can select the optimal path adaptively in the heterogeneous IoT according to the environment. Furthermore, we verify that the MASM improves the transmission efficiency and reduce the transmission delay effectively. The simulation results show that the MASM is stable to changes in the environment and more applicable for the heterogeneous IoT, compared with the other algorithms.

• Journal of Microbiology and Biotechnology
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• v.16 no.7
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• pp.1111-1119
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• 2006

Beauvericins and enniatins are cyclohexadepsipeptides exhibiting various biological activities on animal systems, including humans. Fusarium oxysporum FB1501 (KFCC 11363P) that produces four different cyclohexadepsipeptides was isolated from soil in Korea and the structures of the four cyclohexadepsipeptides elucidated by HPLC, MS, IR, and NMR analyses. The molecular weights for compounds 1,2,3, and 4 were determined to be 654.5, 784.5, 668.6, and 682.5, respectively, on the basis of ESI-MS measurements. The IR spectra for all the compounds exhibited absorptions for ester $(1,733-1,743\;cm^{-1})$ and amide $(1,649-1,655\;cm^{-1})$ bonds that were very similar to those for beauvericin and enniatins with ester and amide absorptions. The results of the NMR analysis $(^{1}H,\;^{13}C,\;135-DEPT,\;COSY,\;HMQC,\;and\;HMBC;\;in\;COCl_{3})$ revealed that compounds 1,3, and 4 consisted of $_{L}-N-methyl\;valine$ (N-MeVal), $_{D}-{\alpha}-hydroxyisovaleic\;acid$ (Hiv), and 2-hydroxy-3-methylpentanoic acid (Hmp) residues (compound 1: three N-MeVal residues, two Hiv residues, and one Hmp residue; compound 3: three N-MeVal residues, one Hiv, and two Hmp residues; compound 4: three N-MeVal residues and three Hmp residues). Therefore, the compounds were identified as enniatin H (compound 1), enniatin I (compound 3), and enniatin MK1688 (compound 4). Compound 2 was analyzed as beauvericin according to 1D and 2D NMR analyses. This study is the first report related to the co-production of beauvericin with other unusual enniatins, such as enniatin H, enniatin I, and enniatin MK1688, by Fusarium oxysporum.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.259-265
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• 2001

Staphylococal infection still remains to be one of the most serious infections, having various complications in the clinical use of indwelling polymeric medical devices. However, there are a few promising systems showing a high antibacterial effect without causing any demage of polymer backbone under biological environments such as blood or body fluid. In order to resolve this problem, we have designed a new antibiotic releasing system via a hydrolysis mechanism. The surface of biomedical polyurethane (PU) was modified by using 1,6-diisocyanatohexane (HMDI) to immobilize the rifampicon. Also, the immobilized rifampicin was designed to be released by a selective cleavage of the unstable carbamate linkage that exists on the rifampicin-immobilized polyurethane (PHR). The immobilization of rifampicin on the surface of polyurethane was confirmed by the disappearance of the characteristics IR absorbance peak of the isocyanate (-NCO) group at $2,267\;cm^{-1}$. The PHR showed a continuous rifampicin release profile under an aqueous environment of 10 mM of PBS (phosphate-buffered saline) for ove 6 days. The rifampicin molecules, which are released from PHR under an optimal bacterial infection environment, had a higher antibacterial activity against both S. aureus and S. epidermidis than rifampicin-incorporated polyurethane (RIP). In addition, the PHR maintained a stable antibacterial effect under a blood-mimic aqueous environment such as bovine calf serum.

• 모자간호학회지
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• v.3 no.2
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• pp.187-196
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• 1993

This study examined nurses' knowledge about breastfeeding (biological signifiance) and their nursing activities for promoting breastfeeding overall deficiency of knowledge about breastfeeding (an average score 12.8 out of 20) and accordingly many nurses did not promote actively merits (preparation, technique, & frequency). We developed new instruments for the measurements of nurses' knowledge (20 items) and activities (30 items). The self-reports of 203 nurses showed of breastfeeding(average score : 65.5 out of 120). Nurses' Knowledge about breastfeeding was significantly related to age, rank of position, and number of nurse' own children promotion of breastfeeding activities by nurses was related to the size of services nurses working in a small or middle sized hospital promoted more breastfeeding activities than a large hospital other factors, such as number of children, also influneced nursing activities for breastfeeding eighty seven percent of the nurses reported that they did not have any in-service education for the breastfeeding. They ascribed reasons for not actively promoting breastfeeding program to the overload of their services and inadequacy of administrative systems.

• Journal of Pharmaceutical Investigation
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• v.32 no.3
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• pp.153-159
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• 2002

Gene therapy is fundamentally a sophisticated drug delivery technology to cure a disease by the transfer of genetic material to modify living cells. In other words, the gene is used as a therapeutic drug much like a chemical compound is employed in chemotherapy. Currently almost 600 clinical trials are underway worldwide since the first clinical trials carried out in 1990 to treat adenosine deaminase deficiency using retroviral vectors. Despite the great progress still is there no gene therapy product being approved as a new drug. This is partly due to a lack of an ideal gene delivery system that is safe and can provide stable, optimal level production of the therapeutic proteins in the cell. This review covers the current status of several different biological and physico-chemical agents that are being developed as gene delivery vehicles. Although gene therapy promises great hopes toward the cure of a broad spectrum of genetic and acquired diseases, the success of gene therapy heavily asks for the development of vector systems for safe and efficient application in humans.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.7
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• pp.3-14
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• 2006

The objective of this study was to develop a GIS-based decision support system (GIS-USLE system) to estimate soil erosion and evaluate its effect on concentrated upland plots in Godang district, Korea. This system was developed for the ArcView environment using A VENUE script. Three modules were used in the GIS-USLE system, namely pre-processing, the USLE factors calculator module, and post-processing. This system benefits from a user friendly environment that allows users with limited computer knowledge to use it. This system was applied to 1,285 individual upland plots ranging from 0.005 to 1.347 ha in size with an average slope steepness of 14 %. The rainfall distributions were estimated using the three methods, namely Mononobe and Yen-Chow with Triangle and with Trapezoid type, and then used to calculate the rainfall erosivity factor. The soil erosion amounts from the 1,285 individual plots in the study area by 2 year return period with a 24h maximum rainfall amount of 154.6 mm were estimated at 5 tons/ha on average. Slope appeared to be the most important factor affecting soil erosion estimation, as expected. The prototype model was applied to the project area, and the results appeared to support the practical applications. By examining many fields simultaneously, this system can easily provide fast estimation of soil erosion and thus reveal the spatial pattern of erosion from fields in a region. This study will help estimate and evaluate soil erosion in concentrated upland districts and identify the best management practices.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.3
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• pp.345-352
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• 2017

Since previous studies have reported that hydroquinone (HQ) exerted immunosuppressive and anti-inflammatory activity, various HQ derivatives have been synthesized and their biological activities investigated. In this study, we explored the anti-inflammatory activity of JS-III-49, a novel HQ derivative, in macrophage-mediated inflammatory responses. JS-III-49 suppressed the production of the inflammatory mediators nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) and down-regulated the mRNA expression of the inflammatory enzymes cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) as well as the expression of the pro-inflammatory cytokines interleukin-6 (IL-6) and IL-$1{\beta}$ without cytotoxicity in LPS-stimulated RAW264.7 cells. JS-III-49 inhibited nuclear translocation of the $NF-{\kappa}B$ transcription factors p65 and p50 by directly targeting Akt, an upstream kinase of the $NF-{\kappa}B$ pathway, in LPS-stimulated RAW264.7 cells. However, JS-III-49 did not directly inhibit the kinase activities of Src and Syk, which are upstream kinases of Akt, in LPS-stimulated RAW264.7 cells. Moreover, JS-III-49 suppressed the nuclear translocation of c-Fos, one of the components of AP-1, by specifically targeting p38, an upstream mitogen-activated protein kinase (MAPK) in the AP-1 pathway in LPS-stimulated RAW264.7 cells. These results suggest that JS-III-49 plays an anti-inflammatory role in LPS-stimulated macrophages by targeting Akt and p38 in the $NF-{\kappa}B$ and AP-1 pathways, respectively.