412 research outputs found
Predictors of mortality among hemodialysis patients in Hamadan Province using random survival forests
Background: Hemodialysis patients are at the high risk for morbidity and mortality. The aim of this study was to find out the predictors of mortality and survival in hemodialysis patients in Hamadan province.
Methods: The numbers of 785 patients during the entire 11 years were enrolled into this historical cohort study. Data were gathered by a checklist of hospital records. The survival time was the time between start of Hemodialysis treatment to patients death as the end point. Random survival forests (RSF) method was used to identify main predictors of survival among the patients.
Results: The median survival time was 613 days. The number of 376 death was occurred. The three most important predictors of survival were hemoglobin, CRP and albumin. RSF method predicted survival better than the conventional Cox-proportional hazards model (out-of-bag C-index of 0.808 for RSF vs. 0.727 for Cox model).
Conclusions: We found that higher levels of CRP, low serum albumin and low serum hemoglobin were the top three most important predictors of survival for HD patients
Discrete-wavelet-transform recursive inverse algorithm using second-order estimation of the autocorrelation matrix
The recursive-least-squares (RLS) algorithm was introduced as an alternative to LMS algorithm with enhanced performance. Computational complexity and instability in updating the autocolleltion matrix are some of the drawbacks of the RLS algorithm that were among the reasons for the intrduction of the second-order recursive inverse (RI) adaptive algorithm. The 2nd order RI adaptive algorithm suffered from low convergence rate in certain scenarios that required a relatively small initial step-size. In this paper, we propose a newsecond-order RI algorithm that projects the input signal to a new domain namely discrete-wavelet-transform (DWT) as pre step before performing the algorithm. This transformation overcomes the low convergence rate of the second-order RI algorithm by reducing the self-correlation of the input signal in the mentioned scenatios. Expeirments are conducted using the noise cancellation setting. The performance of the proposed algorithm is compared to those of the RI, original second-order RI and RLS algorithms in different Gaussian and impulsive noise environments. Simulations demonstrate the superiority of the proposed algorithm in terms of convergence rate comparedto those algorithms
Discrete wavelet transform-based RI adaptive algorithm for system identification
In this paper, we propose a new adaptive filtering algorithm for system identification. The algorithm is based on the recursive inverse (RI) adaptive algorithm which suffers from low convergence rates in some applications; i.e., the eigenvalue spread of the autocorrelation matrix is relatively high. The proposed algorithm applies discrete-wavelet transform (DWT) to the input signal which, in turn, helps to overcome the low convergence rate of the RI algorithm with relatively small step-size(s). Different scenarios has been investigated in different noise environments in system identification setting. Experiments demonstrate the advantages of the proposed DWT recursive inverse (DWT-RI) filter in terms of convergence rate and mean-square-error (MSE) compared to the RI, discrete cosine transform LMS (DCTLMS), discrete-wavelet transform LMS (DWT-LMS) and recursive-least-squares (RLS) algorithms under same conditions
Sickness in Small-Scale Industries in South Punjab: Hurdles & Remedies: A Study of Bahawalpur Estate Area, Pakistan
This study was based on in-depth exploratory investigation of Bahawalpur (Pakistan) industrial estate area to find out the internal and external root causes of sickness in small industries and their solutions. Ashraf et al.(2012) noticed reasons of meager performance of small firms as lack of managerial knowledge, high rate of interest on loans, heavy taxation, poor government policies, owner’s education level and use of outdated technology, that’s why the most of small units have poor success and growth. Shukla (1993) and Reddy et al. (1988) found the causes of sickness in Small Scale industry which were generally related to production, finance, environmental, management and marketing factors.  Collection of data was executed through both primary and secondary sources. Both qualitative and quantitative research methods had been used for the study. Data was primarily collected through structured questionnaires as well as interviews of owners/managers of small industrial units at Bahawalpur industrial estate area. SPSS software was used to analyze the data. In this study we found that 76.9% units were facing energy crisis and almost all the units were also facing high Mark-up problem and Inflation problem. Other obstructions that units were facing comprising the high level of taxation, lack of education, difficulty in accessing credit, lack of market information, lack of management skills etc. which leads to low level of production and unemployment etc. Keywords: Industrial obstructions, Remedies, low productio
Big Software for SmallSats: Adapting cFS to CubeSat Missions
Expanding capabilities and mission objectives for SmallSats and CubeSats is driving the need for reliable, reusable, and robust flight software. While missions are becoming more complicated and the scientific goals more ambitious, the level of acceptable risk has decreased. Design challenges are further compounded by budget and schedule constraints that have not kept pace. NASA's Core Flight Software System (cFS) is an open source solution which enables teams to build flagship satellite level flight software within a CubeSat schedule and budget. NASA originally developed cFS to reduce mission and schedule risk for flagship satellite missions by increasing code reuse and reliability. The Lunar Reconnaissance Orbiter, which launched in 2009, was the first of a growing list of Class B rated missions to use cFS. Large parts of cFS are now open source, which has spurred adoption outside of NASA. This paper reports on the experiences of two teams using cFS for current CubeSat missions. The performance overheads of cFS are quantified, and the reusability of code between missions is discussed. The analysis shows that cFS is well suited to use on CubeSats and demonstrates the portability and modularity of cFS code
Harmonic Scalpel Hemorrhoidectomy Vs Milligan-Morgan Hemorrhoidectomy
Background: To compare Harmonic Scalpel Hemorrhoidectomy (HSH) with classical Milligan Morgan Hemorrhoidectomy (MMH) in terms of operation time and post-operative pain to establish effectiveness of this novel procedure.Methods: A total of 62 patients planned for excision hemorrhoidecotmy were randomly selected into HSH and MMH groups. Mean operation time was calculated during surgery and pain at time of first defecation was recorded on visual analog scale (VAS).Results: Mean VAS after surgery at time of first defecation was 4.32 (SD 0.909) in HSH group and 6.97 (SD 1.426) in MMH group (p value <0.000). Mean Operation time in HSH group was 18.13 (SD 3.956) minutes and that of MMH group was 22.90 (SD 4.901) minutes (P value <0.000).Conclusion: Harmonic Scalpel Hemorrhoidectomy is better than Milligan Morgan hemorrhoidectom
Anaphylactic reaction after intramuscular injection of cyanocobalamin (vitamin B12): a case report
We report a case of anaphylactic reaction to intramuscular injection of cyanocobalamin. This 52-year-old lady was diagnosed as a case of megaloblastic anemia secondary to dietary vitamin B12 deficiency. She had severe anaphylactic reaction after the parenteral administration of cyanocobalamine. Later she received oral vitamin B12 with no adverse effects. The purpose of this case report is to draw attention to the hypersensitive reaction to injectable vitamin B12, which is rarely seen. This could be due to sensitization to the vitamin B12 molecule itself or an IgE mediated reaction. We concluded that anaphylactic reaction to vitamin B12 is a rare but serious side effect and it should be kept in mind while the drug is being administered to the patient, especially via the parenteral route
High Rate Digital Demodulator ASIC
The architecture of High Rate (600 Mega-bits per second) Digital Demodulator (HRDD) ASIC capable of demodulating BPSK and QPSK modulated data is presented in this paper. The advantages of all-digital processing include increased flexibility and reliability with reduced reproduction costs. Conventional serial digital processing would require high processing rates necessitating a hardware implementation in other than CMOS technology such as Gallium Arsenide (GaAs) which has high cost and power requirements. It is more desirable to use CMOS technology with its lower power requirements and higher gate density. However, digital demodulation of high data rates in CMOS requires parallel algorithms to process the sampled data at a rate lower than the data rate. The parallel processing algorithms described here were developed jointly by NASA's Goddard Space Flight Center (GSFC) and the Jet Propulsion Laboratory (JPL). The resulting all-digital receiver has the capability to demodulate BPSK, QPSK, OQPSK, and DQPSK at data rates in excess of 300 Mega-bits per second (Mbps) per channel. This paper will provide an overview of the parallel architecture and features of the HRDR ASIC. In addition, this paper will provide an over-view of the implementation of the hardware architectures used to create flexibility over conventional high rate analog or hybrid receivers. This flexibility includes a wide range of data rates, modulation schemes, and operating environments. In conclusion it will be shown how this high rate digital demodulator can be used with an off-the-shelf A/D and a flexible analog front end, both of which are numerically computer controlled, to produce a very flexible, low cost high rate digital receiver
Central banking and monetary management in islamic financial environment
Continuous growth in Islamic finance calls for studying the framework in which the monetary policy maker (i.e., central bank) performs its functions. Central banks in Muslim countries are using various instruments for monetary policy purpose including interest rate. As a result, Islamic financial institutions (IFIs) are facing issues in benchmarking the price of financial instruments. Acceptable solution to benchmarking lies in the presence of a real economic activity in the base of any proposal and its feasibility for business performance when put against conventional banking. This paper presents empirical evidence of statistical equivalence of nominal GDP growth rate and official interest rate for ‘advanced,’ ‘all,’ and some Muslim countries. We propose nominal GDP growth rate as benchmark for pricing domestic financial transactions of IFIs as well as for pricing external bilateral/ multilateral loans. The paper also suggests nominal income targeting as monetary policy regime and provides a liquidity management mechanism for banking system in Islamic financial environment
Changing Demographics and Economic Growth: A Case Study of Pakistan
The objective of this study is to determine the relationship between various demographic variables and economic growth of Pakistan for the period of 1980-2012. Time series econometric technique has been used for the analysis. Johansen’s co-integration test showed presence of long run relationship between different demographic variables. After establishing the presence of error correction term in the model, variance decomposition test has been used to identify the individual shocks between the variables. The study concludes that the demographic transition has very important role in the economic growth of Pakistan
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