618 research outputs found
NUMERICAL AND EXPERIMENTAL STUDIES ON THE SLOW DRIFT MOTIONS AND THE MOORING LINE RESPONSES OF TRUSS SPAR PLATFORMS
An efficient methodology has been developed for the dynamic analysis of offshore
floating structures. In this methodology, special attention was given to the second
order difference frequency forces and responses. According to this numerical scheme,
a MATLAB program named TRSPAR was developed to predict the dynamic
responses of truss spar platform in time domain. In this program, the truss spar
platform was modeled as a rigid body with three degrees of freedom. Hydrodynamics
of the structure, which include the linear and second order wave forces, mean drift
forces, added mass, radiation damping, wave drift damping and system stiffness were
included in the program. Current and wind forces were also considered showing their
effects on the slow drift responses. The wave forces, including inertia and drag forces,
were calculated using Morison equation assuming the wave field as undisturbed. An
efficient time domain integration scheme was adopted based on Newmark Beta
method.
Comprehensive experimental studies were conducted and the numerical
predictions were systematically compared with model test results. These comparisons
consisted of structure’s dynamic responses in different environmental conditions and
two structural situations. The first situation was the structure with intact mooring lines
and the other one was the structure under mooring line failure. The responses of the
platform with mooring line system damage were investigated with the emphasis on
finding the critical effects of line failure on the resonant responses.
The effects of the second order difference frequency wave forces on the truss spar
motion characteristics were examined numerically. Published numerical results were
used to verify the developed numerical model in predicting the truss spar dynamic
responses when subjected to combined wave, current and wind forces. The effects of strengthening mooring line system on the motion characteristics of the structure were
examined numerically. For the assessment of the fluid to mooring nonlinear
interactions, a deterministic approach based on lumped mass method with equations
of dynamic equilibrium and continuity was adopted. Finally, parametric studies on
deepwater mooring line analysis have been conducted for investigating the
contributions of the various design parameters on mooring line tension.
The experimental results verified the validity of the developed numerical scheme
for prediction of the wave frequency and low frequency motions of the truss spar
platform with its intact mooring and in the case of mooring line damage condition.
RMSD values for the numerical and the experimental results show that the simulated
wave frequency responses (WFR) trend was relatively agreed well with the
experiments compared to the low frequency responses (LFR). For the intact mooring
line condition, RMSD values for the WFR ranged from 109.9 to 182.4 while for LFR
were ranged from 499.6 to 550.2. The same has been noticed in the mooring line
damage condition in which RMSD values ranged from 107.4 to 323.6 and 209.1 to
1074 for WFR and LFR respectively. With regard to the peak responses, good
accuracy has been achieved between the predictions and the measurements. The
percentage errors for the peak responses in the intact mooring and the mooring line
damage conditions were ranged from 9.5% to 17.3%
SYNTHESIS OF POLYMERIZED IONIC LIQUIDS FOR CARBON DIOXIDE CAPTURE
The high level of carbon dioxide (CO2) content in natural gas reserves discovered
lately in Malaysia and some other reservoirs around the globe is one of the major
issues that are being faced by the industry nowadays. The existing processes for CO2
removal suffer from one main setback i.e., the limitation on the maximum content of
CO2 that is allowed in the natural gas feed, at very high purity as required by the
industry. It seems that polymerized ionic liquids showed enhanced CO2 sorption
capacities and fast sorption/desorption rates compared with their corresponding ionic
liquids
Mainstreaming Islamic Religious Education and Secular Education in Schools as Per the Kenyan Basic Education Act 2013
This paper is an attempt to harmonize the local Quranic schools, the Islamic schools (Madarasa) and the secular schools in Kenya. The article is based on existing literature review, the author’s personal experiences and opinions. It is felt that a change be made to integrate the three-parallel curricula. The curriculum of the Quranic and the Arabic schools can be accommodated into the secular curriculum to give time for the pupils for rest or play or do their homework adequately. The current system makes the child run from one school to another. This starts at the age of six and continues until the child completes primary school. This is strenuous for the child. It is hoped that the integrated approach will alleviate this problem. The child needs to be given a chance to interact with his \ her environment so that he \ she can react to it. It should be concerned with the intellectual, emotional, physical and social growth of the child. Keywords: Quranic Schools, integrated curriculum, secular education, colonial administration DOI: 10.7176/JEP/10-27-10 Publication date:September 30th 201
A Comparison Between Divergence Measures for Network Anomaly Detection
International audienceThis paper deals with the detection of flooding attacks which are the most common type of Denial of Service (DoS) attacks. We compare 2 divergence measures (Hellinger distance and Chi-square divergence) to analyze their detection accuracy. The performance of these statistical divergence measures are investigated in terms of true positive and false alarm ratio. A particular focus will be on how to use these measures over Sketch data structure, and which measure provides the best detection accuracy. We conduct performance analysis over publicly available real IP traces (MAWI) collected from the WIDE backbone network. Our experimental results show that Chi-square divergence outperforms Hellinger distance in network anomalies detection
NUMERICAL AND EXPERIMENTAL STUDIES ON THE SLOW DRIFT MOTIONS AND THE MOORING LINE RESPONSES OF TRUSS SPAR PLATFORMS
An efficient methodology has been developed for the dynamic analysis of offshore
floating structures. In this methodology, special attention was given to the second
order difference frequency forces and responses. According to this numerical scheme,
a MATLAB program named TRSPAR was developed to predict the dynamic
responses of truss spar platform in time domain. In this program, the truss spar
platform was modeled as a rigid body with three degrees of freedom. Hydrodynamics
of the structure, which include the linear and second order wave forces, mean drift
forces, added mass, radiation damping, wave drift damping and system stiffness were
included in the program. Current and wind forces were also considered showing their
effects on the slow drift responses. The wave forces, including inertia and drag forces,
were calculated using Morison equation assuming the wave field as undisturbed. An
efficient time domain integration scheme was adopted based on Newmark Beta
method.
Comprehensive experimental studies were conducted and the numerical
predictions were systematically compared with model test results. These comparisons
consisted of structure’s dynamic responses in different environmental conditions and
two structural situations. The first situation was the structure with intact mooring lines
and the other one was the structure under mooring line failure. The responses of the
platform with mooring line system damage were investigated with the emphasis on
finding the critical effects of line failure on the resonant responses.
The effects of the second order difference frequency wave forces on the truss spar
motion characteristics were examined numerically. Published numerical results were
used to verify the developed numerical model in predicting the truss spar dynamic
responses when subjected to combined wave, current and wind forces. The effects of strengthening mooring line system on the motion characteristics of the structure were
examined numerically. For the assessment of the fluid to mooring nonlinear
interactions, a deterministic approach based on lumped mass method with equations
of dynamic equilibrium and continuity was adopted. Finally, parametric studies on
deepwater mooring line analysis have been conducted for investigating the
contributions of the various design parameters on mooring line tension.
The experimental results verified the validity of the developed numerical scheme
for prediction of the wave frequency and low frequency motions of the truss spar
platform with its intact mooring and in the case of mooring line damage condition.
RMSD values for the numerical and the experimental results show that the simulated
wave frequency responses (WFR) trend was relatively agreed well with the
experiments compared to the low frequency responses (LFR). For the intact mooring
line condition, RMSD values for the WFR ranged from 109.9 to 182.4 while for LFR
were ranged from 499.6 to 550.2. The same has been noticed in the mooring line
damage condition in which RMSD values ranged from 107.4 to 323.6 and 209.1 to
1074 for WFR and LFR respectively. With regard to the peak responses, good
accuracy has been achieved between the predictions and the measurements. The
percentage errors for the peak responses in the intact mooring and the mooring line
damage conditions were ranged from 9.5% to 17.3%
Knowledge, attitudes and practices among people in Saudi Arabia regarding COVID-19: A cross-sectional study
Background: The general population’s compliance with preventive measures and legislation is mainly influenced by their knowledge level, attitude, and practices. This study assessed the knowledge, attitude, and practices of public residents towards corona virus disease-2019 preventive measures in Saudi Arabia. Design and Methods: This is a cross-sectional study; it used a validated cross-sectional online survey that received responses from 13 Saudi administrative regions. Results: There were 1513 participants who completed the study (55% females; 77.7%, university education). Knowledge level, attitude, and practices towards corona virus disease-2019 were 81.3%, 86.6%, and 81.9%, respectively. The knowledge subscales showed that 1496 (98.9%) participants knew the system targeted by the virus, 96.2% and 97.3% knew the causative agent and symptoms, 783 (52.2%) participants knew the transmission modes, and 696 (46.0%) participants knew about the complications. The attitude subscales included 1465 (96.5%) participants who had dealt with an infected person, 1451 (95.9%) participants who isolated in a health facility, 1195 (97.0%) participants who knew about hand washing, and 1387 (91.7%) participants who thought the virus spread through home delivery. The practice subscales included 1505 (99.5%) participants who properly disposed of gloves and tissues and 1347 (89.0%) participants who reported safe practices when coughing or sneezing.Conclusions: This study showed satisfactory knowledge, attitude, and practice towards corona virus disease-2019 in Saudi Arabia. The educational level is a dominant influencing factor for knowledge, attitude, and practice
Comparison of Naïve bayes classifier with back propagation neural network classifier based on f - folds feature extraction algorithm for ball bearing fault diagnostic system
This paper is intended to compare the Naïve bayes classifier for ball bearing fault diagnostic system with the back propagation neural network based on the f-folds feature extraction algorithm. The f-folds feature extraction algorithm has been used with different number of folders and clusters. The two classifiers have shown similar classification accuracies. The Naive bayes classifier has not shown any case of false negative or false positive classification. However, the back propagation neural network classifier has shown many cases of false positive and false negative classifications
EFFECT OF INNOVATIVE INTERVENTION IN ELIMINATING STIGMA AND DISCRIMINATION AMONG PEOPLE LIVING WITH AIDS IN KHARTOUM STATE, SUDAN 2013
Since the outbreak of the epidemic, almost 78 million people have been infected with the HIV virus and about 39 million people have died of HIV. Globally, 35.0 million people were recorded to be living with HIV at the end of 2013. Sub-Saharan Africa remains the most severely affected region, and accounts for almost 71% of the people living with HIV worldwide12. HIV/AIDS cases in Sudan increases gradually from one case in 1986 to 10444 cases in 2009, to about 0.67% 13. People living with the disease are the main source through which HIV is spreading. They suffer social stigma and community discrimination. Information, Education, and Communication (IEC) are public health approach aim in changing or reinforcing health-related behaviors to a target audience through communication methods and principles 1. A quasi-experimental study was conducted in Khartoum State, which aim to study the effect of information, education, and communication in reducing stigmatization and discrimination among people living with AIDS/HIV (PLWAIDS/HIV). 25 participants of the total registered members of PLWAIDS/HIV in the society have been selected by systematic random sampling. An intensive intervention using IEC was conducted for six months. Data which were collected before and after the intervention were compared and analyzed using Chi-square test through a computer using SPSS Program. Furthermore, this was presented in tables and graphs. The study revealed that there was a significant elimination of social stigma and a slight decrease in the feeling of community discrimination. The IEC strategy has been proven to be effective in a significant elimination of social stigma and has slightly decreased the feeling of community discrimination
EFFECT OF INNOVATIVE INTERVENTION IN ELIMINATING STIGMA AND DISCRIMINATION AMONG PEOPLE LIVING WITH AIDS IN KHARTOUM STATE, SUDAN 2013
Since the outbreak of the epidemic, almost 78 million people have been infected with the HIV virus and about 39 million people have died of HIV. Globally, 35.0 million people were recorded to be living with HIV at the end of 2013. Sub-Saharan Africa remains the most severely affected region, and accounts for almost 71% of the people living with HIV worldwide12. HIV/AIDS cases in Sudan increases gradually from one case in 1986 to 10444 cases in 2009, to about 0.67% 13. People living with the disease are the main source through which HIV is spreading. They suffer social stigma and community discrimination. Information, Education, and Communication (IEC) are public health approach aim in changing or reinforcing health-related behaviors to a target audience through communication methods and principles 1. A quasi-experimental study was conducted in Khartoum State, which aim to study the effect of information, education, and communication in reducing stigmatization and discrimination among people living with AIDS/HIV (PLWAIDS/HIV). 25 participants of the total registered members of PLWAIDS/HIV in the society have been selected by systematic random sampling. An intensive intervention using IEC was conducted for six months. Data which were collected before and after the intervention were compared and analyzed using Chi-square test through a computer using SPSS Program. Furthermore, this was presented in tables and graphs. The study revealed that there was a significant elimination of social stigma and a slight decrease in the feeling of community discrimination. The IEC strategy has been proven to be effective in a significant elimination of social stigma and has slightly decreased the feeling of community discrimination
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