2,461 research outputs found
On Measuring Skewness and Kurtosis in Short Rate Distributions: The Case of the US Dollar London Inter Bank Offer Rates
Extracting Probabilistic Information from the Prices of Interest Rate Options: Tests of Distributional Assumptions
Normal limit for serum alanine aminotransferase level and distribution of metabolic factors in old population of Kalaleh, Iran
Backgrounds: Normal or elevated values of serum alanine aminotransferase level (ALT) vary in different studies mostly related to characteristics of reference population including age, gender, body mass index, nonalcoholic fatty liver disease (NAFLD), and metabolic syndrome prevalence. Objectives: To measure upper normal limit (UNL) for serum ALT in an apparently healthy Iranian old population (which we had not sufficient data before this study), and its modulating factors. Patients and Methods: All inhabitants (> 50 years old) of Kalaleh, Golestan, Iran (N = 1986) were invited to the study. ALT measurements were performed for all subjects using the same laboratory method. Upper limit of normal (ULN) ALT was calculated based on its 95th percentile in normal weight subjects. Modulating factors of ALT were determined by multivariate analysis. Results: A total of 1309 subjects, with the mean age of 61.5 ± 7.5 years were included. UNL of ALT was 18.8 U/L and 21.4 U/L in women and men, respectively. Based on univariate analysis, waist circumference (r = 0.124, P = 0.01), body mass index (r = 0.118, P = 0.01), triglyceride (r = 0.143, P = 0.01), and having metabolic syndrome (OR = 2.04) modulate ALT levels in men. Also triglyceride (r = 0.119, P = 0.01) modulates ALT levels in women. Conclusions: The calculated level for UNL of ALT is considerably far lower than previous accepted value. Age, gender, ethnicity, and metabolic factors should be accounted in future studies to determine normal ALT level. © 2013, Kowsar Corp.; Published by Kowsar Corp
Hierarchical Design Based Intrusion Detection System For Wireless Ad hoc Network
In recent years, wireless ad hoc sensor network becomes popular both in civil
and military jobs. However, security is one of the significant challenges for
sensor network because of their deployment in open and unprotected environment.
As cryptographic mechanism is not enough to protect sensor network from
external attacks, intrusion detection system needs to be introduced. Though
intrusion prevention mechanism is one of the major and efficient methods
against attacks, but there might be some attacks for which prevention method is
not known. Besides preventing the system from some known attacks, intrusion
detection system gather necessary information related to attack technique and
help in the development of intrusion prevention system. In addition to
reviewing the present attacks available in wireless sensor network this paper
examines the current efforts to intrusion detection system against wireless
sensor network. In this paper we propose a hierarchical architectural design
based intrusion detection system that fits the current demands and restrictions
of wireless ad hoc sensor network. In this proposed intrusion detection system
architecture we followed clustering mechanism to build a four level
hierarchical network which enhances network scalability to large geographical
area and use both anomaly and misuse detection techniques for intrusion
detection. We introduce policy based detection mechanism as well as intrusion
response together with GSM cell concept for intrusion detection architecture.Comment: 16 pages, International Journal of Network Security & Its
Applications (IJNSA), Vol.2, No.3, July 2010. arXiv admin note: text overlap
with arXiv:1111.1933 by other author
Precursors and BRST Symmetry
In the AdS/CFT correspondence, bulk information appears to be encoded in the
CFT in a redundant way. A local bulk field corresponds to many different
non-local CFT operators (precursors). We recast this ambiguity in the language
of BRST symmetry, and propose that in the large limit, the difference
between two precursors is a BRST exact and ghost-free term. Using the BRST
formalism and working in a simple model with global symmetries, we re-derive a
precursor ambiguity appearing in earlier work. Finally, we show within this
model that this BRST ambiguity has the right number of parameters to explain
the freedom to localize precursors within the boundary of an entanglement wedge
order by order in the large expansion.Comment: 12 page
Reliability evaluation of power network: A case study of Fiji Islands
The reliability of electrical power network is the driving force for the development of a country Nowadays most electrical power industries and companies are working for the better satisfaction of the customers while considering the associate cost. Utility companies must have precise information concerning system performance to achieve these goals, consequently guarantee the assets maintenance. The reliability standard of electric power delivered to the customer in Fiji is still in developing stage. Hence it is obvious to have a thorough understanding on the present situation of Fiji islands. In this paper, the performance of electricity delivered being evaluated using commonly used reliability indexes. So that modification and improvement can be done to enhance reliability of Fiji Islands' power network
Scenario Analysis in the Measurement of Operational Risk Capital: A Change of Measure Approach
At large financial institutions, operational risk is gaining the same importance as market and credit risk in the capital calculation. Although scenario analysis is an important tool for financial risk measurement, its use in the measurement of operational risk capital has been arbitrary and often inaccurate. We propose a method that combines scenario analysis with historical loss data. Using the Change of Measure approach, we evaluate the impact of each scenario on the total estimate of operational risk capital. The method can be used in stress-testing, what-if assessment for scenario analysis, and Loss Given Default estimates used in credit evaluations
Antimicrobial activities of grape (Vitis vinifera L.) pomace polyphenols as a source of naturally occurring bioactive components
Grape pomace is a potential source of winery by-products having useful bioactive components. Antimicrobial activities of enzyme-assisted grape pomace polyphenols (GPP) were assessed against Escherichia coli IFO 3301 and Staphylococcus aureus IFO 12732 using plate count and spectrophotometry assays. GPP have shown credential growth inhibition against E. coli and S. aureus, respectively. The higher growth inhibition was mediated by the higher GPP concentrations against both E. coli and S. aureus, which implies dose dependency. GPP also exhibited bactericidal effects against both the Gram-positive and Gram-negative bacteria, whereas, Gram-positive bacteria have shown more susceptibility than Gram-negative bacteria. It is revealed that GPP is a potential source of natural antimicrobial agents.Keywords: Grape pomace, polyphenols, antimicrobial activity
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