• 제목/요약/키워드: K252a

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Development of Hardware Simulator for Operation Analysis of DC Microgrid (DC 마이크로그리드의 동작분석을 위한 하드웨어 시뮬레이터 개발)

  • Lee, Ji-Heon;Han, Byung-Moon
    • Proceedings of the KIPE Conference
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    • 전력전자학회 2011년도 전력전자학술대회
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    • pp.251-252
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    • 2011
  • This paper describes the development of hardware simulator for the operation analysis of DC microgrid, which has a wind power, solar power and fuel cell as a distributed generation, and a supercapacitor and battery as an energy storage. A detailed simulation model for the DC microgrid was developed for operation analysis. Based on simulation results a hardware simulator was built in the lab for the purpose of operation analysis. The developed hardware simulator can be utilized to evaluate with practical manner the performance of actual microgrid in the field.

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Circumstances, Risk Factors, and the Predictors of Falls among Patients in the Small and Medium-sized Hospitals (중소병원 입원환자의 낙상발생 시 현황, 낙상위험요인 및 낙상발생 예측요인)

  • Lee, Young Jin;Gu, Mee Ock
    • Journal of Korean Clinical Nursing Research
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    • 제21권2호
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    • pp.252-265
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    • 2015
  • Purpose: This study examined the circumstances, risk factors, and the predictors of fall incidents among patients in the small and medium-sized hospitals. Methods: Fifty patients with any fall experiences were matched by gender, age, and medical departments with 100 patients without fall incident at the same hospital. Data were collected from 5 small and medium-sized hospitals. Data were analyzed using descriptive statistics, a Chi-square test, a Fisher's exact test, and a logistic regression with the SPSS/WIN 21.0 program. Results: In the patients with falls, the largest number of falls occurred during the day shift, in the patients' rooms, and while they were walking. Further 74.0% of the patients had physical injuries, and 34.0% had to take further medical diagnostic tests. Significant differences were found between the patients with falls and the others on 14 variables (cardiovascular disease, anemia, sedative-hypnotics, vasodilators, narcotic analgesics, dizziness, general weakness, unstable gait, walking aids, anger, anxiety, depression, orientation, and fear of fall). Narcotic analgesic use, dizziness, walking aids, and cardiovascular disease were identified as the predictors of fall incidents. Conclusion: These findings are hoped to be used in developing a fall risk assessment tool and fall prevention nursing programs for small and medium-sized hospitals.

Photoluminescence Characteristics Y2O3:Eu3+ Thin Film Grown on Al2O3(0001) Substrate by PLD (PLD 방법으로 Al2O3(0001) 기판 위에 증착한 Y2O3:Eu3+ 박막의 형광 특성)

  • Yi, Soung-Soo
    • Journal of Sensor Science and Technology
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    • 제13권3호
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    • pp.252-257
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    • 2004
  • $Y_{2}O_{3}:Eu^{3+}$ thin films have been grown on $Al_{2}O_{3}$(0001) substrates by a pulsed laser deposition (PLD) method. The phosphor thin films were deposited at a substrate temperature of 500, 600, and $700^{\circ}C$ under the oxygen pressure of 100, 200, and 300 mTorr. The crystallinity, surface roughness and photoluminescence of the films are highly dependent on the substrate temperature and oxygen pressure. The films grown on $Al_{2}O_{3}$(0001) substrate even under the different substrate temperatures and oxygen pressures exhibited (222) preferred orientation. The luminescent spectra exhibited strong luminescence of ${^{5}D_{0}}-{^{7}F_{2}}$ transition within $Eu^{+3}$ peaking at 612 nm. The crystallinity and luminescence intensity of the films have been improved as the substrate temperature increasing. With increase of oxygen pressure from 50 to 300 mTorr, the crystallinity of the films has been uniformly decreased. The photoluminescence intensity and surface roughness have similar behaviors as a function of oxygen pressure. At 200 mTorr, both photoluminescence intensity and surface roughness show a maximum.

Capacity Assignment and Routing for Interactive Multimedia Service Networks

  • Lim, Byung-Ha;Park, June-Sung
    • Journal of Communications and Networks
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    • 제12권3호
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    • pp.246-252
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    • 2010
  • A binary linear integer program is formulated for the problem of expanding the capacity of a fiber optic network and routing the traffic to deliver new interactive multimedia services. A two-phase Lagrangian dual search procedure and a Lagrangian heuristic are developed. Computational results show superior performance of the two-phase subgradient optimization compared with the conventional one-phase approach.

Hypoglycemic Effect of Cudrania tricuspidata Root Bark (꾸지뽕나무 근피의 항당뇨병 효과)

  • Park, Woong-Yang;Ro, Jai-Seup;Lee, Kyong-Soon
    • Korean Journal of Pharmacognosy
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    • 제32권3호통권126호
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    • pp.248-252
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    • 2001
  • The present study was undertaken to elucidate the hypoglycemic effect and inhibitory effect of Cudrania tricuspidata root bark on aldose reductase activity. C. tricuspidata MeOH ext. 1,000 mg/kg showed a significant blood glucose lowering effect on alloxan-induced hyperglycemic rats and increasing body weight. C. tricuspidata MeOH ext. showed a potent inhibitory effect on bovine lens aldose reductase.

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Automatic analysis of thin-walled laminated composite sections

  • Prokic, A.;Lukic, D.;Ladjinovic, Dj.
    • Steel and Composite Structures
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    • 제16권3호
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    • pp.233-252
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    • 2014
  • In this paper a computer program is developed for the determination of geometrical and material properties of composite thin-walled beams with arbitrary open cross-section and any arbitrary laminate stacking sequence. Theory of thin-walled composite beams is based on assumptions consistent with the Vlasov's beam theory and classical lamination theory. The program is written in Fortran 77. Some numerical examples are given, with complete information about input and output.

Signal-Dependent Chaotic-State-Modulated Digital Secure Communication

  • Farooq, Omar;Datta, Sekharjit
    • ETRI Journal
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    • 제28권2호
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    • pp.250-252
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    • 2006
  • In this letter, a discrete state, discrete time chaotic pseudo random number generator (CPRNG) is presented for stream ciphering of text, audio, or image data. The CPRNG is treated as a finite state machine, and its state is modulated according to the input bit sequence of the signal to be encrypted. The modulated state sequence obtained can be transmitted as a spread spectrum or encrypted data.

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Analysis of Chemical Components of Xylem Sap from 'Hayward' Kiwifruit Canes and Processing of Drink Using the Xylem Sap (참다래 'Hayward' 수액의 화학성분 분석 및 수액을 이용한 음료 제조)

  • Park, Yong Seo;Lim, Keun Cheol;Lee, Ji Heon
    • Horticultural Science & Technology
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    • 제18권6호
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    • pp.808-810
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    • 2000
  • The chemical components of xylem sap collected from kiwifruit (Actinidia chinensis Planch cv. Hayward) trees were analyzed and processing of xylem sap drink were accomplished to increase utilization of xylem sap as a drink. Water content, soluble solids, viscosity, and pH of the xylem sap were 99.60%, 0.90%, 1.01, and 6.50, respectively. In the xylem sap, fructose was the highest among free sugars followed by glucose, sucrose, galactose, and mannitol. The major inorganic components in the sap were calcium, potassium, and magnesium, and calcium was the dominant among them. Ten kinds of amino acids in the xylem sap were detected by amino acid analyzer, and the major amino acids were glutamic acid, lysine, and isoleucine. Glutamic acid was the most dominant amino acid in the xylem sap. Major compositions of xylem sap drink were 74.5% xylem sap, 15% kiwifruit puree and 10% high fructose. Nutritional facts in drink (252 mL) processed by using the xylem sap were 21.8 g sugar, 23.1 mg calcium, 14.1 mg potassium, 554.5 mg amino acid, and 15.6 mg ascorbic acid.

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