On the low SNR capacity of log-normal turbulence channels with full CSI

Author(s):  
Fatma Benkhelifa ◽  
Abdoulaye Tall ◽  
Zouheir Rezki ◽  
Mohamed-Slim Alouini
Keyword(s):  
Low Snr ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 84-88
Author(s):  
Govinda Prasad Dhungana ◽  
Laxmi Prasad Sapkota

 Hemoglobin level is a continuous variable. So, it follows some theoretical probability distribution Normal, Log-normal, Gamma and Weibull distribution having two parameters. There is low variation in observed and expected frequency of Normal distribution in bar diagram. Similarly, calculated value of chi-square test (goodness of fit) is observed which is lower in Normal distribution. Furthermore, plot of PDFof Normal distribution covers larger area of histogram than all of other distribution. Hence Normal distribution is the best fit to predict the hemoglobin level in future.


1993 ◽  
Vol 27 (3-4) ◽  
pp. 31-34 ◽  
Author(s):  
E. Martinez-Manzanares ◽  
M. A. Moriñigo ◽  
D. Castro ◽  
M. C. Balebona ◽  
J. J. Borrego

The objective of this study is to compare different microbiological criteria based on the control of shellfish-growing waters and shellfish flesh, to assess the microbiological quality of the shellfish harvested in a marine zone affected by discharges of a moderately polluted river. Two species of shellfish grown in Mediterranean countries, cockles (Cardium edule) and striped venus (Chamelea gallina) were chosen to carry out this study. A total of 55 samples of diellfish and sea water were collected over the four seasons of the year. According to the results obtained, the US, EEC and Spanish criteria, based on the level of faecal coliforms in shellfish flesh, guaranteed appropriately their safety for human consumption, but among the criteria based on the level of Escherichia coli, only the Australian criterion has been shown to be totally safe, this microorganism being the best indicator of the presence of Vibrio parahaemolyticus and Salmonella. For the criteria based on the analysis of indicators in seawater, the indicators which relate to the age of faecal pollution, such as spores of clostridium sulfite reducer and faecal streptococci are the best indexes of the presence of pathogens in shellfish. Furthermore, criteria that establish the percentage of water samples that fulfill the microbiological level specified, or log-normal distributions of indicators such as total coliforms, faecal coliforms and E. coli, are better than mean counts.


1995 ◽  
Vol 32 (2) ◽  
pp. 45-52 ◽  
Author(s):  
H. Z. Sarikaya ◽  
A. M. Saatçi

Total coliform bacteria have been chosen as the indicator organism. Coliform die-away experiments have been carried out in unpolluted sea water samples collected at about 100 m off the coastline and under controlled environmental conditions. The samples were transformed into one litre clean glass beakers which were kept at constant temperature and were exposed to the solar radiation. The membrane filter technique was used for the coliform analysis. The temperature ranged from 20 to 40° C and the dilution ratios ranged from 1/50 to 1/200. Coliform decay rate in the light has been expressed as the summation of the coliform decay rate in the dark and the decay rate due to solar radiation. The solar radiation required for 90 percent coliform removal has been found to range from 17 cal/cm2 to 40 cal/cm2 within the temperature range of 25 to 30° C. Applying the linear regression analysis two different equations have been given for the high (I>10 cal/cm2.hour) and low solar intensity ranges in order to determine the coliform decay rate constant as a function of the solar intensity. T-90 values in the light have been found to follow log-normal distribution with a median T-90 value of 32 minutes. The corresponding T-90 values in the dark were found to be 70-80 times longer. Coliform decay rate in the dark has been correlated with the temperature.


Engevista ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Alexandre Santos Francisco ◽  
Ivan Napoleão Bastos
Keyword(s):  

Diversas partes das colunas de direção de automóveis são fixadas por interferência de diâmetros e, adicionalmente, por ação de cravamento mecânico. Para determinar o efeito destes procedimentos na fixação dos rolamentos nas juntas de colunas de direção foram realizados ensaios de remoção dos rolamentos. Foram testadas populações amostrais das juntas com e sem cravamento. A influência dos procedimentos de cravamento e da interferência dimensional na integridade das colunas de direção foi determinada experimentalmente com curvas força versus deslocamento. Os resultados indicaram que o cravamento mais que dobra a força de remoção e aumenta em 24% a energia absorvida na remoção total. Testes estatísticos de aderência mostraram que a força de remoção obedece a uma distribuição log-normal. A partirdestes dados pôde-se determinar a confiabilidade estrutural das juntas de colunas de direção, cujo resultado indica que com o cravamento a taxa esperada de falha é próxima de zero para uma carga mínima de 2000 N. Este trabalho permitiu conhecer a importância do cravamento no procedimento de sujeição de juntas automotivas, e estabelecer novos padrões na montagem das colunas de direção, usando argumentos mecânicos e estatísticos.


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