Chebyshev-like inequalities for dam models

1972 ◽  
Vol 9 (03) ◽  
pp. 617-629 ◽  
Author(s):  
Bruce W. Turnbull
Keyword(s):  
Conditional Distributions ◽  
The Past ◽  
The Mean ◽  
Mean Time ◽  
Quantities Of Interest

A dam model is proposed for which it is assumed that the conditional distributions of the inputs, given the past, are known only to lie in some class M . For selected M , bounds are derived on various quantities of interest such as the mean time to first emptiness. The case of normal inputs is treated in greater detail and a release rule is discussed. The techniques used are similar to those used in the theory of gambling as developed by Dubins and Savage (1965).

Chebyshev-like inequalities for dam models

1972 ◽  
Vol 9 (3) ◽  
pp. 617-629 ◽  
Author(s):  
Bruce W. Turnbull
Keyword(s):  
Conditional Distributions ◽  
The Past ◽  
The Mean ◽  
Mean Time ◽  
Quantities Of Interest

A dam model is proposed for which it is assumed that the conditional distributions of the inputs, given the past, are known only to lie in some class M. For selected M, bounds are derived on various quantities of interest such as the mean time to first emptiness. The case of normal inputs is treated in greater detail and a release rule is discussed. The techniques used are similar to those used in the theory of gambling as developed by Dubins and Savage (1965).

Study of Hazard Rate Functions on the Cumulative Damage Phenomenon

2011 ◽  
Vol 27 (1) ◽  
pp. 47-55 ◽  
Author(s):  
K. S. Wang
Keyword(s):  
Hazard Rate ◽  
Failure Mechanisms ◽  
Operation Time ◽  
Cumulative Damage ◽  
Hazard Rates ◽  
Type B ◽  
The Past ◽  
Rate Functions ◽  
The Mean ◽  
Mean Time

ABSTRACTIn this paper different failure mechanisms which yield cumulative damage are investigated through two types of hazard rate functions. They have been studied during the past two decades. Type A was developed early by assuming the hazard rate as a function of reliability. There are two kinds of trend, one follows the negative logistic decay model, the other the negative Gompertz decay. Some modifications are suggested according to the failure tendency and convenience of fittings. Type B is developed recently by assuming the hazard rate as a function of the expected operation time, T, which is defined as the integration of reliability over the time, normalized by the mean-time-between-failure. In both types the proposed hazard rates grow with the time monotonically. Typical examples are taken to examine these models, meanwhile the comparisons with the Weibull-typed distribution are also made. The results show that the most of proposed relations are successful in the expression of cumulative damage phenomenon, especially the Type B is a better choice even compared with the Weibull-typed description in some respects. The advantages of the models are discussed based on the physical meanings involved in the parameters.

scholarly journals On selecting the most reliable components

1998 ◽  
Vol 2 (2) ◽  
pp. 133-145 ◽  
Author(s):  
Dylan Shi
Keyword(s):  
Markov Process ◽  
Death Process ◽  
Series System ◽  
Birth And Death Process ◽  
Retrograde Motion ◽  
The Past ◽  
Optimal Policies ◽  
Average Proportion ◽  
The Mean ◽  
Mean Time

Consider a series system consisting of n components of k types. Whenever a unit fails, it is replaced immediately by a new one to keep the system working. Under the assumption that all the life lengths of the components are independent and exponentially distributed and that the replacement policies depend only on the present state of the system at each failure, the system may be represented by a birth and death process. The existence of the optimum replacement policies are discussed and the ε-optimal policies axe derived. If the past experience of the system can also be utilized, the process is not a Markov process. The optimum Bayesian policies are derived and the properties of the resulting process axe studied. Also, the stochastic processes are simulated and the probability of absorption, the mean time to absorption and the average proportion of the retrograde motion are approximated.

scholarly journals PROPOSALS FOR STRATEGIES IN THE CURRICULA OF TECHNICAL UNIVERSITIES

2017 ◽  
Vol 19 (4) ◽  
Author(s):  
VALENTIN ZICHIL ◽  
VALENTIN NEDEFF ◽  
CAROL SCHNAKOVSZKY ◽  
CĂTĂLIN DROB
Keyword(s):  
Birth Rate ◽  
Educational Activity ◽  
Product Analysis ◽  
New Techniques ◽  
The Past ◽  
The Mean ◽  
Technical High Schools ◽  
The University ◽  
Mean Time ◽  
Virtual Higher Education

<p>Into the past 20 years, in Romania is registered a continuous decrease of the birth rate. At this problem it has to be added the youth wish to work in economics and laws systems, where the length of time study is smaller (only 3 years), gaining the possibility to own rapidly a salary. In those conditions, technical universities have to challenge greater provocations. The paper propose a solution, partially applied in “Vasile Alecsandri” University  of Bacau, to solve some of these new problems using a few solutions such as: “virtual” higher education and distance learning methods in order to achieve as much as is possible from the goals presented in known theories of career development. In the mean time, the strategy of the staff is presented, to make the university attractive for the youth, in order to continue the educational activity and to form better and better qualified specialists, able to face the new techniques technologies in manufacturing and product analysis. A model of curricula for the first two academic years in technical high schools is proposed.</p>

Homeless men with psychosis are spending more time shelterless

2020 ◽  
pp. 103985622092886
Author(s):  
Daniel Burton ◽  
Simon Jones ◽  
Trevor Carlisle ◽  
Alex Holmes
Keyword(s):  
Affordable Housing ◽  
Low Cost ◽  
Housing First ◽  
Mental Health Team ◽  
Health Team ◽  
The Past ◽  
Homeless Men ◽  
The Mean ◽  
Mean Time

Objective: The objective of this study was to determine if homeless men with psychosis in central Melbourne have spent a greater proportion of the past 12 months in homeless settings as compared with the same group 15 years previously. Method: A 12-month accommodation history was collected from all men with psychosis assessed by a homeless outreach mental health team over a 12-month period commencing 2018 and compared with data from 2006. Results: Between 2006 and 2018, the percentage of time spent homeless in the previous 12 months rose from 50% to 80% ( p = 0.0001). The mean time spent shelterless increased from 72 days to 149 days ( p = 0.0001). Conclusions: The amount of time spent homeless has increased in men with psychosis assessed in central Melbourne. This finding suggests that men with psychosis are becoming increasingly entrenched in homeless settings. Addressing this trend requires an increased emphasis on assertive outreach, greater access to acute inpatient and long-term rehabilitation units, and more low cost affordable housing, including housing first facilities.

Study on Nanomechanical Properties of Dragonfly Wing

2009 ◽  
Vol 79-82 ◽  
pp. 1325-1328 ◽  
Author(s):  
Ching Hsin Chang ◽  
Ku En Ting ◽  
Kuen Tsan Chen
Keyword(s):  
Structural Properties ◽  
Surface Characteristics ◽  
Flight Mechanics ◽  
The Other ◽  
Nanoindentation Test ◽  
Nanomechanical Properties ◽  
Dragonfly Wing ◽  
The Past ◽  
The Mean ◽  
Mean Time

The flight mechanics of dragonflies including hovering and taking off backwards, flight sideways and vertical directions has been attentions in Bionics. The dragonfly wing consists of the networks of various veins and membranes to make the structural properties complicated. In the past investigations, surface characteristics of dragonfly wing were measured by nanoindentation test. Thus the aim of this study will comprehensively concern the nanomechanical properties of veins, membrane and pterostigma of the wing of the dragonfly with nanoindentation. In the mean time, the modulus and hardness of the wing of the dragonfly’s composites including lengthwise vein, transverse vein, membrane and pterostigma are measured. The value of modulus of lengthwise vein is greater than the other structures. The value of modulus of transverse vein is the smallest due to its soft behavior. Its hardness is also smaller than others.

Predicting Daily Maintenance Dose of Fluindione, an Oral Anticoagulant Drug

1996 ◽  
Vol 75 (05) ◽  
pp. 731-733 ◽  
Author(s):  
V Cazaux ◽  
B Gauthier ◽  
A Elias ◽  
D Lefebvre ◽  
J Tredez ◽  
...  
Keyword(s):  
Effective Dose ◽  
Maintenance Dose ◽  
Successive Approximations ◽  
Hemorrhagic Complication ◽  
Simple Method ◽  
Individual Variations ◽  
Anticoagulant Drug ◽  
The Mean ◽  
Mean Time ◽  
Daily Maintenance Dose

SummaryDue to large inter-individual variations, the dose of vitamin K antagonist required to target the desired hypocoagulability is hardly predictible for a given patient, and the time needed to reach therapeutic equilibrium may be excessively long. This work reports on a simple method for predicting the daily maintenance dose of fluindione after the third intake. In a first step, 37 patients were delivered 20 mg of fluindione once a day, at 6 p.m. for 3 consecutive days. On the morning of the 4th day an INR was performed. During the following days the dose was adjusted to target an INR between 2 and 3. There was a good correlation (r = 0.83, p<0.001) between the INR performed on the morning of day 4 and the daily maintenance dose determined later by successive approximations. This allowed us to write a decisional algorithm to predict the effective maintenance dose of fluindione from the INR performed on day 4. The usefulness and the safety of this approach was tested in a second prospective study on 46 patients receiving fluindione according to the same initial scheme. The predicted dose was compared to the effective dose soon after having reached the equilibrium, then 30 and 90 days after. To within 5 mg (one quarter of a tablet), the predicted dose was the effective dose in 98%, 86% and 81% of the patients at the 3 times respectively. The mean time needed to reach the therapeutic equilibrium was reduced from 13 days in the first study to 6 days in the second study. No hemorrhagic complication occurred. Thus the strategy formerly developed to predict the daily maintenance dose of warfarin from the prothrombin time ratio or the thrombotest performed 3 days after starting the treatment may also be applied to fluindione and the INR measurement.

Scrub typhus (Orientia tsutsugamushi), A rapidly spreading epidemic in Chennai - A standalone lab experience

2016 ◽  
Vol 5 (09) ◽  
pp. 4896
Author(s):  
Sripriya C.S.* ◽  
Shanthi B. ◽  
Arockia Doss S. ◽  
Antonie Raj I. ◽  
Mohana Priya
Keyword(s):  
Scrub Typhus ◽  
Clinical Symptoms ◽  
Clinical Manifestations ◽  
Febrile Illness ◽  
Orientia Tsutsugamushi ◽  
The Past ◽  
Igm Elisa ◽  
The Mean ◽  
Specific Symptoms ◽  
Symptoms And Signs

Scrub typhus (Orientia tsutsugamushi), is a strict intracellular bacterium which is reported to be a recent threat to parts of southern India. There is re-emergence of scrub typhus during the past few years in Chennai. Scrub typhus is an acute febrile illness which generally causes non-specific symptoms and signs. The clinical manifestations of this disease range from sub-clinical disease to organ failure to fatal disease. This study documents our laboratory experience in diagnosis of scrub typhus in patients with fever and suspected clinical symptoms of scrub typhus infection for a period of two years from April 2014 to April 2016 using immunochromatography and IgM ELISA methods. The study was conducted on 648 patients out of whom 188 patients were found to be positive for scrub typhus. Results also showed that pediatric (0 -12 years) and young adults (20 – 39 years) were more exposed to scrub typhus infection and female patients were more infected compared to male. The study also showed that the rate of infection was higher between September to February which also suggested that the infection rate is proportional to the climatic condition. Statistical analysis showed that the mean age of the patients in this study was 37.6, standard deviation was 18.97, CV % was 50.45. 

Retrospective analysis of mortality within 30 days of systemic anticancer therapy and comparison with a previous audit at an Australian Regional Cancer Centre

2021 ◽  
pp. 107815522110160
Author(s):  
Bernadatte Zimbwa ◽  
Peter J Gilbar ◽  
Mark R Davis ◽  
Srinivas Kondalsamy-Chennakesavan
Keyword(s):  
Checkpoint Inhibitors ◽  
Anticancer Therapy ◽  
Mortality Rates ◽  
Feedback Process ◽  
Time To Death ◽  
Cancer Centre ◽  
Haematology Patients ◽  
The Mean ◽  
Regional Cancer Centre ◽  
Mean Time

Purpose To retrospectively determine the rate of death occurring within 14 and 30 days of systemic anticancer therapy (SACT), compare this against a previous audit and benchmark results against other cancer centres. Secondly, to determine if the introduction of immune checkpoint inhibitors (ICI), not available at the time of the initial audit, impacted mortality rates. Method All adult solid tumour and haematology patients receiving SACT at an Australian Regional Cancer Centre (RCC) between January 2016 and July 2020 were included. Results Over a 55-month period, 1709 patients received SACT. Patients dying within 14 and 30 days of SACT were 3.3% and 7.0% respectively and is slightly higher than our previous study which was 1.89% and 5.6%. Mean time to death was 15.5 days. Males accounted for 63.9% of patients and the mean age was 66.8 years. 46.2% of the 119 patients dying in the 30 days post SACT started a new line of treatment during that time. Of 98 patients receiving ICI, 22.5% died within 30 days of commencement. Disease progression was the most common cause of death (79%). The most common place of death was the RCC (38.7%). Conclusion The rate of death observed in our re-audit compares favourably with our previous audit and is still at the lower end of that seen in published studies in Australia and internationally. Cases of patients dying within 30 days of SACT should be regularly reviewed to maintain awareness of this benchmark of quality assurance and provide a feedback process for clinicians.

Vitamin D Level Stability in Dystrophinopathy Patients on Vitamin D Supplementation

2021 ◽  
pp. 1-7
Author(s):  
Naomi Vather-Wu ◽  
Matthew D. Krasowski ◽  
Katherine D. Mathews ◽  
Amal Shibli-Rahhal
Keyword(s):  
Vitamin D ◽  
Retrospective Cohort ◽  
Vitamin D Supplementation ◽  
Hydroxyvitamin D ◽  
Frequent Monitoring ◽  
25 Hydroxyvitamin D ◽  
The Mean ◽  
Stable Maintenance ◽  
Mean Time

Background: Expert guidelines recommend annual monitoring of 25-hydroxyvitamin D (25-OHD) and maintaining 25-OHD ≥30 ng/ml in patients with dystrophinopathies. Objective: We hypothesized that 25-OHD remains stable and requires less frequent monitoring in patients taking stable maintenance doses of vitamin D. Methods: We performed a retrospective cohort study, using the electronic health record to identify 26 patients with dystrophinopathies with a baseline 25-OHD ≥30 ng/mL and at least one additional 25-OHD measurement. These patients had received a stable dose of vitamin D for ≥3 months prior to their baseline 25-OHD measurement and throughout follow-up. The main outcome measured was the mean duration time the subjects spent with a 25-OHD ≥30 ng/mL. Results: Only 19% of patients dropped their 25-OHD to <  30 ng/ml, with a mean time to drop of 33 months and a median nadir 25-OHD of 28 ng/mL. Conclusions: These results suggest that measurement of 25-OHD every 2–2.5 years may be sufficient in patients with a baseline 25-OHD ≥30 ng/mL and who are on a stable maintenance dose of vitamin D. Other patients may require more frequent assessments.

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