77 research outputs found
Transmitting audio via fiber optics under nonlinear effects and optimized tuning parameters based on Co-simulation of matlab and optisystemTM
Limitations of conventional wires such as copper wires are causing dispersion and distortion of the message signal for long distances communication especially for the wide bandwidths. The ability of fiber optic to overcome this problem is making it a dominant transmission medium. Despite of this major positive attribute of optic fibers, there is still a downside for using the fiber optic communication; that is the nonlinearity problem especially at the very high frequency bandwidth. For the first time, a desigen of an audio signal is suggested and executed in MatLab with an integration with OptiSystemTM software to discuss and solve this issu. The audio signal is then transmitted in different shapes of modulation signals (NRZ, RZ & RC) for different distances (100 km & 75 km) via a fiber optic media to be received in a receiving part of the simulated system. Three tests are used to do so. The first is the Quality-factor (Q-Factor) against the received power, second test is eye diagram performance and finally is the measuring of the amplitude of output (received) signal for each modulation signal shape using the Oscilloscope Visualizer. The NZR modulation signal was found to be the best one of the three used signalsâ types in all three tests. The Q-factor for NRZ pulse shape (=12) was higher than that for RZ (=10) and RC (=8) for a 100 km distance at the same received power level
Studi Awal: Desain Jejaring Kawasan Konservasi Perairan di Pantai Barat Sulawesi Selatan
This study was related to government policies , especially PP No 60 / 2007 article 19 of the mandate of the establishment of network of marine conservation areas in various levels, both local ( provincial ), national, regional and global. One aspect is the establishment of a network of ecological data availability . The method used is the spatial analysis techniques combined with field surveys in the waters of the West Coast of South Sulawesi , especially in the waters of Makassar . Research shows that the condition of each ecosystem ; seagrass with range from 32.5 to 72.5 % with an average of 54 % (Good Condition) condition of coral reef ecosystems which range covered of 17.5 to 57.5 % with an average of 39.5 , % (critical condition ) and condition of mangrove ecosystem with moderate conditions with an area 142 hectares which in the category of denc
THE STATUS OF ORGANIC POLLUTION AND THEIR SPATIAL DISTRIBUTION IN THE WEST COAST OF SOUTH SULAWESI
Aquaculture activities produce organic wastes that are discharged into coastal waters and may impact the water quality. This research aimed to study the status of organic pollution and its spatial distribution on the west coast of South Sulawesi, Indonesia. Water was sampeld from two locations (Punaga Village, Takalar Regency (an open water system), and Bojo Village, Barru District (in a bay, a semi-closed water system)). Water quality was assessed by using the STORET index. Whilst to assess the spatial distribution of organic waste, an interpolation technique was used. Results showed that the water quality was categorized as highly polluted by organic pollution. The distribution of the organic pollutant, however, showed a different spatial pattern between the two locations. The difference was may be due to the different origin of the pollutant and geomorphology of the sampling locations
A Nationwide Study of the âJuly Effectâ Concerning Postpartum Hemorrhage and Its Risk Factors at Teaching Hospitals across the United States
Objective To assess the âJuly effectâ and the risk of postpartum hemorrhage (PPH) and its risk factors across the U.S. teaching hospitals. Method This study used the 2018 Nationwide Inpatient Sample (NIS) and included 2,056,359 of 2,879,924 single live-birth hospitalizations with low-risk pregnancies across the U.S. teaching hospitals. The International Classification of Diseases, Tenth Revision (ICD-10) from the American Academy of Professional Coders (AAPC) medical coding was used to identify PPH and other study variables. Multivariable logistic regression models were used to compare the adjusted odds of PPH risk in the first and second quarters of the academic year vs. the second half of the academic year. Results Postpartum hemorrhage occurred in approximately 4.19% of the sample. We observed an increase in the adjusted odds of PPH during July through September (adjusted odds ratios (AOR), 1.05; confidence interval (CI), 1.02â1.10) and October through December (AOR, 1.07; CI, 1.04â1.12) compared to the second half of the academic year (January to June). Conclusions This study showed a significant âJuly effectâ concerning PPH. However, given the mixed results concerning maternal outcomes at the time of childbirth other than PPH, more research is needed to investigate the âJuly effectâ on the outcomes of the third stage of labor. This studyâs findings have important implications for patient safety interventions concerning MCH
Underlying Primary Causes of Chronic Renal Failure: A Three-Year Study in Al-Thawra General Hospital, Sana'a, Yemen
Objective: To estimate the underlying primary diseases of chronic renal failure (CRF) among patients attending Al-Thawra General Hospital, Sana'a, and Yemen.Methods: This was a cross-sectional, hospital-based study of 566 patients diagnosed with chronic kidney diseases (CKD). It studied the cases attending Al-Thawra General Hospital over a threeâyear period from January 2013 to December 2015.Results: Out of 566 patients, 339 (59.9%) were males. The mean age of the patients at diagnosis of CKD was 39.51 years, most of whom (36.6%) were of the age group of 21â35 years. Hypertension was the most frequent cause (43.2%) of CRF, followed by different infectious diseases such as malaria, schistosomiasis and bacterial infections (19%) and obstructive nephropathy (17.9%). On the other hand, CRF of unknown etiology represented 15.2% of cases. Other causes of CRF diabetic nephropathy (9.7%), effect of antibiotics and analgesics (7.0%), ischemic heart disease (4.8%, polycystic kidney disease (3.5%) and congenital anomalies (3.4%). The least common causes were autoimmune diseases, bleeding, traumatic accidents and chronic diarrhea, being responsible for 2.2%, 1.8%, 0.9% and 0.4% of CRF cases, respectively.Conclusions: The majority of CKD cases in our study were males aged between 21 and 35 years old. In addition, most cases of CKD are due to hypertension, followed by infections and obstructive nephropathy. Application of future prevention and control measures are highly recommended to reduce the burden of CRF in Yemen for early detection and proper management of its underlying primary conditions/diseases
Panorametry: suggestion of a method for mandibular measurements on panoramic radiographs
<p>Abstract</p> <p>Background</p> <p>Orthopantomography (panoramic radiography) has been used for the study of measurements involving particularly the prediction of the eruption of impacted lower third molars and analyses of measurements of the ramus and head of mandible. The discrepancies involved with the projection of this radiographic image has stimulated the search for further ways to use it, particularly in orthodontic treatments and oral and maxillofacial surgeries. The author proposes a graphimetric method for the mandible, based on panoramic radiography. The results are expressed in linear and angular measurements, aiming at bilateral comparisons as well as the determination of the proportion of skeletal and dental structures, individually and among themselves as a whole. The method has been named Panorametry, and allows measurement of the mandible (Mandibular Panorametry) or the posterior mandibular teeth (Dental Panorametry). When combining mandible and maxilla, it should be referred to as Total Panorametry. It may also be used, in the future, with Cone Beam computed tomography (CT) images, and in this case it may be mentioned as CT Panorametry.</p
On Stratified Ranked Set Sampling for Regression Estimators
Two types of stratified regression estimators for the population mean, the separate and the combined estimators, are investigated using stratified random sampling scheme (SSRS) and stratified ranked set sampling (SRSS). We derived mean and variance of the proposed estimators. In addition, we compared the performance of the regression estimators using SRSS with respect to SSRS by simulation. Our derivations and simulations revealed that our proposed estimators are unbiased and using SRSS is more efficient than using SSRS. The procedure are illustrated by using the bilirubin levels in babies in a neonatal intensive care unit data
On Improving the Performance of Logistic Regression Analysis Via Extreme Ranking
Logistic regression models for dichotomous or ordinal dependent variables is one of the generalized linear models. They have been frequently applied in several fields. In this chapter, we present more efficient and powerful performance of the logistic regression models analysis when a modified extreme ranked set sampling (modified ERSS) or moving extreme ranked set sampling (MERSS) are used and further improving the performance when a modified Double extreme ranked set sampling (modified DERSS) is used. We propose that ranking could be performed based on an available and easy to rank auxiliary variable which is associated with the response variable. Analytically and through simulations, we showed the superiority performance of the logistics regression analysis when modified ERSS, MERSS, and DERSS are used compared with using the simple random sample (SRS). For illustration purposes of the procedures developed, we use a real dataset from 2011/12 National Survey of Childrenâs Health (NSCH)
- âŠ