• Information and Communications Magazine
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• v.29 no.6
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• pp.9-13
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• 2012

IDC의 에너지 효율화 측정지수로 IDC 전체 전력 중 ICT장비에 사용한 전력의 비율을 지수화 한 PUE가 활용되고 있다. PUE는 IDC 운영자 및 관리자가 신속하게 현재의 IDC의 에너지 사용에 대한 효율성을 파악하여 에너지 효율 향상에 대한 목표수립을 가능하게 한다. 아직까지 국가적으로 명확한 IDC 에너지 효율화 기준이 없는 우리나라의 대형 IDC를 중심으로 그린그리드의 PUE를 내부 관리지표로 사용하고 있으나 적용 기준이 IDC 전용 데이터센터 위주로 작성되어 있어서 IDC 이외의 용도가 복합적으로 구성되어 있는 우리나라 IDC의 PUE를 객관적으로 측정할 수 있는 표준 마련이 시급한 실정이다. 이에 본 연구에서는 IDC 에너지 사용 측정방법과 PUE 구조 및 활용 현황에 대하여 기술하였다. 본 연구는 IDC의 에너지 효율화 측정에 활용할 수 있으며, 향후 제정될 국가적인 IDC 에너지 효율화 지수에 활용될 수 있다.

• IMMUNE NETWORK
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• v.10 no.6
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• pp.188-197
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• 2010

Background: Lichen-derived glucans have been known to stimulate the functions of immune cells. However, immunostimulatory activity of glucan obtained from edible lichen, Umbilicaria esculenta, has not been reported. Thus we evaluated the phenotype and functional maturation of dendritic cells (DCs) following treatment of extracted glucan (PUE). Methods: The phenotypic and functional maturation of PUE-treated DCs was assessed by flow cytometric analysis and cytokine production, respectively. PUE-treated DCs was also used for mixed leukocyte reaction to evaluate T cell-priming capacity. Finally we detected the activation of MAPK and NF-${\kappa}B$ by immunoblot. Results: Phenotypic maturation of DCs was shown by the elevated expressions of CD40, CD80, CD86, and MHC class I/II molecules. Functional activation of DCs was proved by increased cytokine production of IL-12, IL-$1{\beta}$, TNF-${\alpha}$, and IFN-${\alpha}/{\beta}$, decreased endocytosis, and enhanced proliferation of allogenic T cells. Polymyxin B, specific inhibitor of lipopolysaccharide (LPS), did not affect PUE activity, which suggested that PUE was free of LPS contamination. As a mechanism of action, PUE increased phosphorylation of ERK, JNK, and p38 MAPKs, and enhanced nuclear translocation of NF-${\kappa}B$ p50/p65 in DCs. Conclusion: These results indicate that PUE induced DC maturation via MAPK and NF-${\kappa}B$ signaling pathways.

• Journal of the Society of Disaster Information
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• v.16 no.4
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• pp.768-783
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• 2020

Purpose: In response to the critical risk of fire due to the characteristic of Publicly used establishments(hereinafter referred to as PUE), 'Special Act on the Safety Control of PUE' was enacted in 2006 and is still in operation. However, in spite of numerous revisions so far, still there are problems to be resolved. This study analyses the regulatory regime of fire safety in UK to find measures which could fundamentally improve the safety management of PUE. Method: This study compares and analyses the safety management system of PUE in Korea and the case of the UK by using the comparative research method. Result: As a result of the qualitative analysis, some noticeable systems and concepts of the UK regulatory regime have been discovered(e.g. 'Responsible person', 'Fire risk assessment', 'Fire safety audit', etc.) and consequently, 'Proposal for the Fire Safety Management System for PUE' is designed based on the findings from examples in the UK and drawbacks of safety management of PUE. Conclusion: This study proposes the way to improve the safety management of PUE into a more rational and effective system by analysing the case of the UK, which reorganised the fire safety management to the private sector centered, in which the fire authority minimizes intervention.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.1
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• pp.218-224
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• 1999

This study was designed to investigate the effect of Pueraria radix extract on lipid metabolism in the rats fed high fat diet. Male sprague dawley rats were given 5% Pueraria radix extract and fed diet containing 20 weight % fat. The results obtained were summarized as follows. Serum ALT and AST activities were reduced by Pueraria radix extract. Levels of total lipid, total cholesterol and triglyceride in the serum were higher in the HF group than in the control, but showed no significant differences between control and HF Pue group. Liver total lipid, total cholesterol and triglyceride contents were increased by high fat diet, but were lower in the HF Pue group than in the HF group. Fat absorption rate was increased with high fat diet feeding and higher in the HF Pue group than in the HF group.

• IEIE Transactions on Smart Processing and Computing
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• v.2 no.6
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• pp.357-366
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• 2013

Spectrum sensing, as a fundamental functionality of Cognitive Radio (CR), enables Secondary Users (SUs) to monitor the spectrum and detect spectrum holes that could be used. Recently, the security issues of Cognitive Radio Networks (CRNs) have attracted increasing research attention. As one of the attacks against CRNs, a Primary User Emulation (PUE) attack compromises the spectrum sensing of CR, where an attacker monopolizes the spectrum holes by impersonating the Primary User (PU) to prevent SUs from accessing the idle frequency bands. Energy detection is often used to sense the spectrum in CRNs, but the presence of PUE attack has not been considered. This study examined the effect of PUE attack on the performance of energy detection-based spectrum sensing technique. In the proposed protocol, the stationary helper nodes (HNs) are deployed in multiple stages and distributed over the coverage area of the PUs to deliver spectrum status information to the next stage of HNs and to SUs. On the other hand, the first stage of HNs is also responsible for inferring the existence of the PU based on the energy detection technique. In addition, this system provides the detection threshold under the constraints imposed on the probabilities of a miss detection and false alarm.

• Journal of Life Science
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• v.27 no.3
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• pp.339-345
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• 2017

Carotenoids are natural lipid-soluble pigments, which are produced primarily by bacteria, algae, and plants. Many studies have focused on the identification, production, and utilization of natural sources of astaxanthin from algae, yeast, and crustacean byproducts as an alternative to the synthetic pigment, which is mostly used today. The aim of the present study was to identify a mutant of Paracoccus haeundaensis by exposure to UV and ethyl methanesulfonate (EMS). The mutant was then exposed to nutrient stress conditions to isolate an astaxanthin-hyperproducing strain, followed by characterization of the mutant. The survival rate decreased in accordance with an increase in the UV exposure time and an increase in the EMS concentration. A mutant of the original P. haeundaensis strain was identified that showed hyperproduction of astaxanthin following exposure to UV irradiation (20 min) and EMS treatment (0.4 M concentration). The optimal culture conditions for the PUE mutant were $25^{\circ}C$, pH 7-8, and 3% NaCl. The effects of various carbon and nitrogen sources on the growth and astaxanthin production of PUE were examined. The addition of 1% raffinose and 3% potassium nitrate influenced cell growth and astaxanthin production. The selected mutant exhibited an increase of 1.58 folds in astaxanthin content compared to initial wild type strain. A genetically stable mutant strain obtained using mutagen (UV irradiation and EMS treatment) may be a suitable candidate for further industrial scale production of astaxanthin.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.2
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• pp.147-157
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• 2021

Coronary microembolization (CME) is associated with cardiomyocyte apoptosis and cardiac dysfunction. Puerarin confers protection against multiple cardiovascular diseases, but its effects and specific mechanisms on CME are not fully known. Hence, our study investigated whether puerarin pretreatment could alleviate cardiomyocyte apoptosis and improve cardiac function following CME. The molecular mechanism associated was also explored. A total of 48 Sprague-Dawley rats were randomly divided into CME, CME + Puerarin (CME + Pue), sham, and sham + Puerarin (sham + Pue) groups (with 12 rats per group). A CME model was established in CME and CME + Pue groups by injecting 42 ㎛ microspheres into the left ventricle of rats. Rats in the CME + Pue and sham + Pue groups were intraperitoneally injected with puerarin at 120 mg/kg daily for 7 days before operation. Cardiac function, myocardial histopathology, and cardiomyocyte apoptosis index were determined via cardiac ultrasound, hematoxylin-eosin (H&E) and hematoxylin-basic fuchsin-picric acid (HBFP) stainings, and TdT-mediated dUTP nick-end labeling (TUNEL) staining, respectively. Western blotting was used to measure protein expression related to the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/glycogen synthase kinase-3β (GSK-3β) pathway. We found that, puerarin significantly ameliorated cardiac dysfunction after CME, attenuated myocardial infarct size, and reduced myocardial apoptotic index. Besides, puerarin inhibited cardiomyocyte apoptosis, as revealed by decreased Bax and cleaved caspase-3, and up-regulated Bcl-2 and PI3K/Akt/GSK-3β pathway related proteins. Collectively, puerarin can inhibit cardiomyocyte apoptosis and thus attenuate myocardial injury caused by CME. Mechanistically, these effects may be achieved through activation of the PI3K/Akt/GSK-3β pathway.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.7
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• pp.371-376
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• 2013

Recently, many studies related to reducing the energy consumption in data centers have been conducted. These studies have mainly focused on the air intake and exhaust system of a computer room air handling unit (CRAH) in the server room, diffuser type, suppression and discharge of the heat generated from the server, and the air-side economizer system. In this study, the energy consumption of the conventional central chilled water cooling system is compared with the energy consumption of the air-side economizer system. We also examined how changes of differential pressure by each filter have influenced energy consumption, using the power usage effectiveness (PUE). Results show that the PUE was improved, and energy consumption decreased, by applying the air-side economizer system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.7
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• pp.3414-3434
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• 2016

Classical key generation is complicated to update and key distribution generally requires fixed infrastructures. In order to eliminate these restrictions researchers have focused much attention on physical-layer (PHY-layer) based key generation methods. In this paper, we present a PHY-layer fingerprints based fuzzy key generation scheme, which works to prevent primary user emulation (PUE) attacks and spectrum sensing data falsification (SSDF) attacks, with multi-node collaborative defense strategies. We also propose two algorithms, the EA algorithm and the TA algorithm, to defend against eavesdropping attacks and tampering attacks in mobile cognitive radio networks (CRNs). We give security analyses of these algorithms in both the spatial and temporal domains, and prove the upper bound of the entropy loss in theory. We present a simulation result based on a MIMO-OFDM communication system which shows that the channel response characteristics received by legitimates tend to be consistent and phase characteristics are much more robust for key generation in mobile CRNs. In addition, NIST statistical tests show that the generated key in our proposed approach is secure and reliable.

• Elastomers and Composites
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• v.54 no.4
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• pp.271-278
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• 2019

Polyurethane elastomers (PUEs) were synthesized using trans-1,4-bis(isocyanatomethyl) cyclohexane (1,4-H₆XDI), poly(oxytetramethylene) glycol, 1,4-butanediol (BD), and 1,1,1-trimethylol propane (TMP). To control the molecular aggregation state and mechanical properties of these PUEs, hard segment contents of 20 and 30 wt% and BD/TMP ratios of 10/0 and 8/2 were chosen. Differential scanning calorimetry and small-angle X-ray scattering measurements revealed that the degree of microphase separation increased with an increase in both hard segment content and BD ratio. The Young's modulus and strain at break of the 1,4-H₆XDI-based PUE were 6-20 MPa and 5-15, respectively. Incorporation of 20% TMP as a cross-linking agent into BD increased the melting temperature of the hard segment chains, that is, heat resistance, and decreased the Young's modulus. This could be due to the low density of the physical cross-linking network and the dispersion of hard segment chains in the soft segment matrix in the PUE in the presence of 20% TMP.