• Title/Summary/Keyword: R-Factor

Search Result 5,307, Processing Time 0.038 seconds

A Study on Irradiation Effect by $Co^{60}$ of the R-C Series-Parallel Circuits (방사선조사에 의한 R-C 직.병렬회로에서의 손상효과에 관한 연구)

  • 서국철;조성욱
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.1 no.2
    • /
    • pp.57-61
    • /
    • 1987
  • The characteristis of all the instruments and materials used in atomic industry are changed due to irradiation damages by the effects of radiation activities. In this study when R-C series-parallel circuits are irradiated by $\gamma$-ray, variations in its electrical properties have been investigated. The following results are obtained. 1) In the R-C series circuit, the impedance variation ratio is increased as the irradiation quantity is increased up to $10^6[r]$, and above $10^6[r]$, the impedance variation ratio reached at the saturated condition. In the saturated condition, the increasing value was about 1.25 (%). 2) In the R-C series circuit, the power factor variation ratio is decreased as the irradiation quantity is in creased up to $10^6[r]$, and above $10^6[r]$, the power factor variation ratio reached at the saturated condition. In the saturated condition, the decreasing value was about 0.5(%). 3) In the R-C parallel circuit, the impedance variation ratio is increased as the irradiation quentity is increased up to $10^6[r]$, and above $10^6[r]$, the impedance variation reached at the saturated condition. In the saturated condition, the increasing value was about 0.5.(%). 4) In the R-C parallel circuit, the power factor variation ratio is decreased as the irradiation quantity is increased up to $10^6$[r], and above $10^6$[r], the power factor variation ratio reached at the saturated condition. In the saturated condition, the decreasing value was about 1.3(%).

  • PDF

2R++: Enhancing 2R FTL to Identify Warm Pages (2R++: Warm Page 식별을 통한 2R FTL 개선)

  • Hyojun, An;Sangwon, Lee
    • KIPS Transactions on Computer and Communication Systems
    • /
    • v.11 no.12
    • /
    • pp.419-428
    • /
    • 2022
  • Since in-place updates for pages are not allowed in flash memory, all new page writes should be written in an out-of-place manner. The old overwritten pages are invalidated. Such invalidated pages eventually trigger the costly garbage collection process. Since the garbage collection causes numerous read and write operations, it is one of the flash memory's major performance issues. In 2R, it modified the garbage collection algorithm, which applies the I/O characteristics of the On-Line Transaction Process workload to improve the Write Amplification Factor. However, this algorithm has a region pollution problem. Therefore, in this paper, we developed 2R++ that additionally separates pages with long access intervals to solve the region pollution problem. 2R++ introduces an extra bit per block to separate warm pages based on a second chance mechanism. Prevents warm pages from being misidentified as cold pages to solve region pollution problem. We conducted the experiments on TPC-C and Linkbench to make the performance comparison. The experiment showed that 2R++ achieved a Write Amplification Factor improvement of 57.8% and 13.8% compared to 2R, respectively.

A Study on the Students' Cognition of Chemistry in Science High School by Factor Analysis of Mathematics and Science Achievement (수학·과학 성취도의 요인 분석으로 본 과학고등학교 학생들의 화학 교과에 대한 인식 연구)

  • Shin, Dong-Seon;Choi, Hojun;Kim, Bong Gon
    • Journal of the Korean Chemical Society
    • /
    • v.64 no.2
    • /
    • pp.119-129
    • /
    • 2020
  • For effective teaching-learning activities for students with diverse talents in science high schools, it is important for teachers to understand students' individual differences in perceiving and processing information in the natural world, depending on the students' various talents and subject characteristics. The purpose of this study is to examine the students' cognition of chemistry in science high school through correlations and factor analysis of mathematics/science achievement. In addition, this study attempted to examine the cognition of chemistry subject according to R&E classes. The main participants of the study were freshmen of G science high school (296 students) who entered after three times of curriculum reforms and new admission processes and the students in two other science high schools in Gyeongnam and Ulsan were included. The correlation and factor analysis were conducted by exploratory factor analysis by IBM SPSS Statistics 25 programs. The results of this study were as follows: First, in the correlation analysis between mathematics and science achievement, it was confirmed that the Pearson's coefficient of chemistry showed higher positive correlation coefficient than that of other science subjects. Second, in the factor analysis of mathematics and science achievements, it was found that the factor indicators were divided into two factors as logical-mathematical (mathematics and physics) and naturalistic (life science and earth science). Third, in the factor analysis, it was confirmed that the chemistry is recognized as the subject that requires both logical-mathematical and naturalistic intelligence. Finally, it was confirmed that students' cognitions of chemistry subject were found to differ according to the R&E classes. In other words, the participants of R&E chemistry class, unlike other students, were found to recognize chemistry as the subject that logical-mathematical intelligence is needed.

The Correlation Analysis and Correction factor of BMD in Forearm and Lumbar with DXA (DXA를 이용한 전완부와 요추부 골밀도 검사의 보정계수 및 상관관계 연구)

  • Han, Man-Seok
    • Journal of Digital Convergence
    • /
    • v.11 no.12
    • /
    • pp.551-556
    • /
    • 2013
  • The Forearm and the lumbar spine bone mineral density bone mineral density values obtained through, T-score and Z-score correlation between numerical and calibration function obtained as a result of any one part to another part of the results is intended to infer. Groups of 66 patients, 11 patients by age 20-70 were composed of patients measured with the forearm and lumbar spine bone mineral density T-score and Z-score of the survey for each of the three factors that correlated to assess the correlation Find the correction factor to obtain the relationship. Bone mineral density of the correlation coefficient R = 0.769 correction factor is Y = 1.541X + 0.133. T-score of correlation coefficient R = 0.768 and the correction factor Y = 0.715X - 0.4 is Z-score of the correlation coefficient R = 0.635 correction factor Y = 0.751X - 0.162. It is regarded that there will be a clinical availability which can analogize the result of a part by using the result of the other part.

Lack of any Prognostic Role of Insulin-Like Growth Factor-1 Receptor in Non-Small Cell Lung Cancer

  • Dilli, Utku Donem;Yildırim, Mustafa;Suren, Dinc;Alikanoglu, Arsenal;Kaya, Vildan;Goktas, Sevil;Yildiz, Mustafa;Sezer, Cem;Gunduz, Seyda
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.14
    • /
    • pp.5753-5757
    • /
    • 2014
  • Background: The purpose of this study is to determine whether the IGF1R expression has a prognostic role in non-small cell lung cancer. Materials and Methods: Forty-seven patients histopathologically diagnosed with small cell lung cancer upon bronchoscopic biopsy or resection materials were included in the study. IGF1R expression was examined via immunohistochemical methods. In samples, >10% staining were assessed as positive and ${\leq}10%$ as negative. Information about demographic datas and treatments was obtained by retrospective searches of patient files. Results: IGF1R expression was determined as positive in 38 (80.9%) and as negative in 9 (19.1%) patients. There was no significant relation between IGF1R expression and histological sub-type, local invasion, lymph node and metastasis status (p=0.842, p=0.437, 0.064, 0.447, respectively). There was also no correlation with IGF1R expression and survival (p=0.141). Conclusions: There are conflicting results between IGF1R and its prognostic effects in the various studies. It has been claimed in some studies it is not related to prognosis as in our study, and in some studies it has been claimed that it is a good prognostic factor whereas in some studies it has been claimed as being a factor for worse prognosis. We think that IGF1R expression in non-small cell lung carcinoma patients deserves further analysis, because of its potential prognostic and predictive roles.

Inhibitory Principles from Magnolia officinalis on Tumor Necrosis $Factor-{\alpha}$ Production in Lipopolysaccharide-Activated RAW264.7 cells

  • Cho, Jae-Youl;Park, Ji-Soo;Chae, Sook-Hee;Lee, June-Goo;Yoo, Eun-Sook;Baik, Kyong-Up;Lee, Jong-Soo;Park, Myung-Hwan
    • Natural Product Sciences
    • /
    • v.5 no.2
    • /
    • pp.70-74
    • /
    • 1999
  • In the course of a search for tumor necrosis factor $(TNF)-{\alpha}$ inhibitory compounds from medicinal plants, we identified neolignans, honokiol and magnolol, from the alcoholic extract of Magnolia offcinalis as active inhibitory principles. These compounds dose-dependently inhibited $TNF-{\alpha}$ production without displaying cytotoxicity and their inhibitory activities measured by $IC_{50}$ values were 53.7 and $61.4\;{\mu}M$, respectively.

  • PDF

Investigation on the selection of capillary tube for the alternative refrigerant R-407C (대체냉매 R-407C의 모세관 선정에 관한 연구)

  • 김용환;김창년;박영무
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.10 no.1
    • /
    • pp.56-65
    • /
    • 1998
  • In this paper, experimental investigation of capillary tube performance for R-407C is performed. The experimental setup is made of real vapor-compression refrigerating system. In this study, mass flow rate is measured for capillary tubes of various diameter and length as inlet pressure and degree of subcooling are changed. These data are compared with the results of a numerical model. The mass flow rates of the numerical model are less than by 14% compared with the measured mass flow rates. It is found that mass flow rate and length for R-407c are less than those of R-22 under the same condition. Also based on this experimental study and the numerical model, a set of capillary tube selection charts for R-407C is constructed.

  • PDF

ON JACOBSON AND NIL RADICALS RELATED TO POLYNOMIAL RINGS

  • Kwak, Tai Keun;Lee, Yang;Ozcan, A. Cigdem
    • Journal of the Korean Mathematical Society
    • /
    • v.53 no.2
    • /
    • pp.415-431
    • /
    • 2016
  • This note is concerned with examining nilradicals and Jacobson radicals of polynomial rings when related factor rings are Armendariz. Especially we elaborate upon a well-known structural property of Armendariz rings, bringing into focus the Armendariz property of factor rings by Jacobson radicals. We show that J(R[x]) = J(R)[x] if and only if J(R) is nil when a given ring R is Armendariz, where J(A) means the Jacobson radical of a ring A. A ring will be called feckly Armendariz if the factor ring by the Jacobson radical is an Armendariz ring. It is shown that the polynomial ring over an Armendariz ring is feckly Armendariz, in spite of Armendariz rings being not feckly Armendariz in general. It is also shown that the feckly Armendariz property does not go up to polynomial rings.

Diffuse alveolar hemorrhage and recombinant factor VIIa treatment in pediatric patients

  • Park, Jeong A
    • Clinical and Experimental Pediatrics
    • /
    • v.59 no.3
    • /
    • pp.105-113
    • /
    • 2016
  • Diffuse alveolar hemorrhage (DAH) is a life-threatening pulmonary complication in patients with hematologic malignancies or autoimmune disorders. The current treatment options, which include corticosteroids, transfusions, extracorporeal membrane oxygenation (ECMO), and immunosuppressants, have been limited and largely unsuccessful. Recombinant activated factor VII (rFVIIa) has been successfully administered, either systemically or bronchoscopically, to adults for the treatment of DAH, but there are few data on its use in pediatric patients. The current literature in the PubMed database was reviewed to evaluate the efficacy and risk of rFVIIa treatment for DAH in pediatric patients. This review discusses the diagnosis and treatment of DAH, as well as a new treatment paradigm that includes rFVIIa. Additionally, the risks and benefits of off-label use of rFVIIa in pediatric patients are discussed.

Controller of the Capacitor Commutated Converter for Hvdc

  • Tsubota, Shinji;Funaki, Tsuyoshi;Matsuura, Kenji
    • Proceedings of the KIPE Conference
    • /
    • 1998.10a
    • /
    • pp.914-919
    • /
    • 1998
  • A Capacitor Commutated Converter (CCC) has less difficulty of commutation failure in comparison to the conventional line commutated converter. This paper proposes the Ar1R control of the CCC in the inverter operation, which deserves as the Ar1R of the conventional converter. The CCC can be operated in high power factor area by using the proposing Ar1R control. The voltage stability at an AC bus connected the CCC inverter is investigated and estimated its ability of preventing the AC voltage collapse. To estimate the voltage stability, this paper developed the simplified converter mathematical model and led the VSF index. The results shows that the AC voltage stability is guaranteed and enables the interconnection to an weak AC system, when compensation factor of the compensation capacitor is higher than 200%.

  • PDF