• The KIPS Transactions:PartC
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• v.15C no.2
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• pp.93-102
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• 2008

The network weather map and bandwidth time-series graph are popularly used to understand the current and past traffic condition of NSP, ISP, and enterprise networks. These systems collect traffic performance data from a SNMP agent running on the network devices such as routers and switches, store the gathered information into a DB, and display the network performance status in the form of a time-series graph or a network weather map using Web user interface. Most of current enterprise networks are constructed in the form of a hierarchical tree-like structure with multi-Gbps Ethernet links, which is quietly different from the national or world-wide backbone network structure. This paper focuses on the network weather map for current enterprise network. We start with the considering points in developing a network weather map system suitable for enterprise network. Based on these considerings, this paper proposes the best way of using SNMP in constructing a network weather map system. To prove our idea, we designed and developed a network weather map system for our campus network, which is also described in detail.

• Convergence Security Journal
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• v.4 no.3
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• pp.47-55
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• 2004

Currently used to manage a whole bunch of networks is the Client/Server Network Management Technique in which a central manager system supports a number of managed ones. Unfortunately it has a big drawback: wasting network resources, most of all bandwidth, which is mainly caused by too much traffic between the central manager system and the managed ones. In a way to overcome this weak point, we have designed a new type of system, a Configuration Management System (CMS), based on code mobility which has been used in distributed network management systems. In this thesis we have compared the CMS with the currently used network management system, identified class to make Mobile Code, and analyzed the techniques of other network management systems in order to verify the validity of the new system.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.13
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• pp.5311-5316
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• 2014

Nuclear factor erythroid 2-related factor 2 (Nrf2) has been recognized as a transcription factor that controls mechanisms of cellular defense response by regulation of three classes of genes, including endogenous antioxidants, phase II detoxifying enzymes and transporters. Previous studies have revealed roles of Nrf2 in resistance to chemotherapeutic agents and high level expression of Nrf2 has been found in many types of cancer. At physiological concentrations, luteolin as a flavonoid compound can inhibit Nrf2 and sensitize cancer cells to chemotherapeutic agents. We reported luteolin loaded in phytosomes as an advanced nanoparticle carrier sensitized MDA-MB 231 cells to doxorubicin. In this study, we prepared nano phytosomes of luteolin to enhance the bioavailability of luteolin and improve passive targeting in breast cancer cells. Our results showed that cotreatment of cells with nano particles containing luteolin and doxorubicin resulted in the highest percentage cell death in MDA-MB 231cells (p<0.05). Furthermore, luteolin-loaded nanoparticles reduced Nrf2 gene expression at the mRNA level in cells to a greater extent than luteolin alone (p<0.05). Similarly, expression of downstream genes for Nrf2 including Ho1 and MDR1 were reduced significantly (p<0.05). Inhibition of Nrf-2 expression caused a marked increase in cancer cell death (p<0.05). Taken together, these results suggest that phytosome technology can improve the efficacy of chemotherapy by overcoming resistance and enhancing permeability of cancer cells to chemical agents and may thus be considered as a potential delivery system to improve therapeutic protocols for cancer patients.

• Journal of Chest Surgery
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• v.26 no.6
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• pp.427-440
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• 1993

The paucity of donor hearts for transplantation can be remedied by distant heart procurement. Prolonging donor heart preservation is essential for successful clinical cardiac transplantation. Thirty-two isolated rat hearts were perfused with Krebs-Henseleit buffer solution for 15 minutes, arrested and preserved at 4 oC for 4 hours, and then reperfused for 25 minutes. The following three groups were prepared and hemodynamic changes, creatine kinase-MB isoenzyme levels and ultrastructural changes of the myocardium were analysed before and after cardiac arrest. ; Group I : the heart was arrested with the cardioplegic solution [Plegisol, potassium : 16 mM, sodium : 120 mM] and then stored in a solution with ionic compositions of the extracellular fluid [Hartman, potassium : 4 mM, sodium : 130 mM] ; Group II : the heart was arrested with the cardioplegic solution and stored in a solution with ionic compositions of the intracellular fluid [Modified Euro-Collins, potassium : 108 mM, sodium : 10 mM] ; Group III : the heart was arrested with the cardioplegic solution containing adenosine 20 uM, and then stored in a solution with ionic compositions of the intracellular fluid [Modified University of Wisconsin solution, potassium : 119 mM, sodium: 23 mM]. Left ventricular developed pressure at 20 minutes of the reperfusion was significantly higher in group III [64.3 $\pm$ 3.12 mmHg, p<0.01] and group II [58.3 $\pm$ 1.55 mmHg, p<0.05] as compared with group I [51.4$\pm$ 2.78 mmHg]. The time to induce cardiac arrest after infusion of cardioplegic solution with adenosine 20 uM [5.3 $\pm$ 0.30 second, p<0.005] was significantly shorter than without adenosine [10.6$\pm$ 0.55 second]. Coronary flow at 20 minutes of the reperfusion was augmented significantly in group III [9.6$\pm$ 0.50 ml/min, p<0.05, p<0.05] as compared with group I [8.0 $\pm$ 0.41 ml/min] and group II [8.1$\pm$ 0.51 ml/min]. Percentage recovery of left ventricular developed pressure at 20 minutes of the reperfusion was significantly higher in group III [94.6$\pm$ 2.51 %, p<0.005] as compared with group II and in group II [83.1 $\pm$ 1.22 %, p<0.005] as compared with group I [69.9 $\pm$ 1.73 %], and also percentage recovery of coronary flow at 20 minutes of the reperfusion was significantly higher in group III [82.3 $\pm$ 3.86 %, p<0.05] as compared with group II [71.4 $\pm$ 3.46 %] but there was no significant difference between group I and group II. Measured level of creatine kinase-MB isoenzyme at 15 minutes of the reperfusion was significantly lower in group III [1.23 $\pm$ 0.16 ng/ml, p<0.025] and group II [1.42$\pm$ 0.10 ng/ml, p<0.05] as compared with group I [1.79 0.14 ng/ml]. In the semiquantitative evaluation of the ultrastructural changes of the myocardium, mitochondrial score was lower in group III [0.7 $\pm$ 0.21] than in group I [3.1$\pm$ 0.28] and group II [1.7 $\pm$ 0.19], and also the other structural score was lower in group III [2.7$\pm$ 0.99] than in group I [7.9 $\pm$ 0.89] and group II [5.0 $\pm$ 1.22]. In conclusion, the solution with ionic compositions of the intracellular fluid is appropriate for prolonged cardiac preservation, and it appears to be better preserving method for distant procurement when the donor heart is rapidly arrested with cardioplegic solution containing adenosine 20 uM, and then stored with Modified University of Wisconsin solution.

• Elastomers and Composites
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• v.52 no.4
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• pp.287-294
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• 2017

Nanocomposites based on $SnO_2-Mn$ were synthesized by the reaction of tin (II) chloride dihydrate and manganese (II) chloride tetrahydrate at a molar ratio of 10:1 in the presence of ammonium hydroxide at $80^{\circ}C$. The $SnO_2-Mn$ nanocomposites were stirred with fullerene [$C_{60}$] in a mass ratio of 2:1 in tetrahydrofuran to prepare $SnO_2-Mn-C_{60}$ nanocomposites; these nanocomposites were obtained upon heating the mixture of $SnO_2-Mn$ nanocomposites and fullerene [$C_{60}$] in an electric furnace at $700^{\circ}C$ for 2 h. The synthesized $SnO_2-Mn-C_{60}$ nanocomposites were confirmed through various characterization methods such as X-ray diffraction and scanning electron microscopy. The photocatalytic activities of the $SnO_2-Mn-C_{60}$ nanocomposites were demonstrated by the degradation of the organic dyes BG, MB, MO, and RhB under 254 nm irradiation and evaluated using UV-Vis spectrophotometry.

• The Transactions of the Korea Information Processing Society
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• v.7 no.6
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• pp.1803-1809
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• 2000

With the wide usage of the Internet, there use of pre-developed software is becoming important more and more in the development of various communication software. In this paper, the architecture to reuse the communication software is proposed. It is applied to the development of MIB-II system group of SNMP agent software for reusing. If Communication software is developed using this architecture, the software development life cycle will be abridged and the development cost will be reduced.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10b
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• pp.1323-1326
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• 2001

서브네트워크에서 실시간으로 통신 트래픽을 감시하고, 트래픽 정보를 바탕으로 시계열 분석을 이용해 트래픽의 변화추이를 예측할 수 있는 시스템을 설계 및 구현한다. SNMP를 이용한 MIB-II 정보를 바탕으로 하는 분석 방법은 누적 데이터를 기본으로 하는 관리 방법으로 이상 징후의 판단이 실시간 감시에는 적합하지 않은 점이 있다. 따라서, 본 논문에서는 실시간 트래픽 감시를 위해 서브네트워크에 들어오거나 나가는 트래픽의 양을 측정하여 분석하고, 이 정보를 바탕으로 특정 시점 이후의 트래픽 추이를 시계열 분석 방법을 이용하여 미래의 트래픽 양을 예측하는 알고리즘을 시스템으로 구현한다. 예측 알고리즘으로는 AR, MA, ARMA, ARIMA 모델중에 평균 제곱 오차를 최소로 가지는 알고리즘을 선택하여 예측하도록 설계한다. 개발되는 시스템을 망 관리자가 전체 통신 네트워크의 부하 상태를 예상할 수 있게 하여 신속하고 예방적인 대응을 할 수 있다.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.84-84
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• 2002

This study was to investigate generation of the specific neuronal cell in vitro from the neural progenitors derived from human embryonic stem (hES, MB03) cells. For the neural progenitor cell formation, we produced embryoid bodies (EB: for 5 days, without mitogen) from hES cells and then neurospheres (for 7-10 days, 20 ng/㎖ of bFGF added N2 medium) from EB. And then for the differentiation into neuronal cells, neural progenitor cells were cultured in N2 medium (without bFGF) supplemented with brain derived neurotrophic factor (BDNF, 5 ng/㎖) or platelet derived growth factor-bb (pDGF-bb, 20ng/㎖) for 2 weeks. (omitted)

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.619-621
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• 2004

인터넷 사용자의 폭발적인 증가로 인하여 차별화된 웹 서비스를 제공해주는 웹 응용프로그램들의 개발이 요구되고 있다. 그러므로 웹 서버내의 품질향상을 보장해주는 웹 QoS 기술은 전자상거래나 웹 호스팅 같은 부분에서 점점 더 중요한 문제로 대두되고 있다. 그러나 대부분의 웹 서버들은 FIFO 방식의 최선 서비스만을 제공하며, 정보의 중요도나 정보를 제공받는 사용자의 중요도에 따라 차별화된 품질보장을 제공하지 못한다. 본 논문에서는 클러스터링 웹 서버 환경에서 차별화 서비스를 위한 동적 부하분산 시스템을 제안한다. 웹 서비스의 차별화된 품질보장을 제공하는 웹 서버 구현을 위해 커널 수준 접근 방식과 응용프로그램 접근방식을 제시한다. 제안 시스템에서는 웹 서비스의 신뢰성과 반응속도를 개선시키기 위해 IP수준의 가장법과 터널링 기술을 이용하여 웹 서버의 부하를 분산한다. 그리고 SNMP의 시스템 부하관련 MIB-II 정보를 검출하여 부하 분산에 반영함으로써 동적인 부하분산이 가능하도록 한다.

• Journal of the Korean Ceramic Society
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• v.49 no.6
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• pp.511-517
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• 2012

Pd/MWCNT/$TiO_2$ composites were synthesized by a sol-gel technique using multi-walled carbon nanotubes (MWCNT), palladium (II) chlorite ($PdCl_2$) and titanium tetrachloride ($TiCl_4$) as the carbon, palladium and titanium precursors. The Pd/MWCNT/$TiO_2$ composites prepared were characterized by BET surface area measurements, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The photocatalytic activity of the composites was evaluated using the degradation of methylene blue (MB) under UV and visible light irradiation as a model.