scholarly journals A filtered renewal process as a model for a river flow

2005 ◽  
Vol 2005 (1) ◽  
pp. 49-59 ◽  
Author(s):  
Mario Lefebvre
Keyword(s):  
Poisson Process ◽  
Exponential Distribution ◽  
Renewal Process ◽  
River Flow ◽  
Realistic Model ◽  
Delaware River ◽  
The Usa ◽  
The One ◽  
Peak Value

Various models, based on a filtered Poisson process, are used for the flow of a river. The aim is to forecast the next peak value of the flow, given that another peak was observed not too long ago. The most realistic model is the one when the time between the successive peaks doesnothave an exponential distribution, as is often assumed. An application to the Delaware River, in the USA, is presented.

On some characterizations of the poisson process

1989 ◽  
Vol 26 (01) ◽  
pp. 176-181
Author(s):  
Wen-Jang Huang
Keyword(s):  
Poisson Process ◽  
Renewal Process ◽  
Arrival Time ◽  
Random Variables ◽  
Poisson Processes

In this article we give some characterizations of Poisson processes, the model which we consider is inspired by Kimeldorf and Thall (1983) and we generalize the results of Chandramohan and Liang (1985). More precisely, we consider an arbitrarily delayed renewal process, at each arrival time we allow the number of arrivals to be i.i.d. random variables, also the mass of each unit atom can be split into k new atoms with the ith new atom assigned to the process Di, i = 1, ···, k. We shall show that the existence of a pair of uncorrelated processes Di, Dj, i ≠ j, implies the renewal process is Poisson. Some other related characterization results are also obtained.

Reflections on FDA and WHO recommendations concerning clinical trials

1989 ◽  
Vol 4 (2) ◽  
pp. 117-122 ◽  
Author(s):  
J.-F. Dreyfus ◽  
D. Cremniter ◽  
J.D. Guelfi
Keyword(s):  
Clinical Trials ◽  
Drug Users ◽  
Objective Evaluation ◽  
World Health ◽  
Measuring Instruments ◽  
New Techniques ◽  
The Usa ◽  
The One ◽  
Health Organization

SummaryWe are still confronted by numerous different nosographic models and problems concerning the objective evaluation of patients progress during treatment. It is interesting to consider the consequences of this situation in psychiatry which still involves a relative diversity of practical methods used in clinical trials. The recommendations of the USA Food and Drug Administration, on the one hand, constitute a highly structured and precise reference. The World Health Organization, on the other hand, promulgates general recommendations resulting from a compromise designed to satisfy the greatest number of clinicians.Despite the apparently diverse principles and the different practical methods they propose, both those sets of recommendations have been useful in inspiring clinicians to reflect upon these different methodological approaches. The qualities of the inclusion criteria used in the study of patients and the sensitivity of the different measuring instruments have allowed psychotropic drug users as well as producers to recognize the need for a certain rigour in clinical trials.The FDA and WHO guidelines have certainly improved the quality of clinical trials in psychopharmacology. However, they also represent a source of resistance to innovation.A series of consensus meetings to first reconcile US and European points of view and later to include new techniques in the recognized sets of methods would therefore be helpful.

Numerical investigation on a melt-blowing die with internal stabilizers

2019 ◽  
pp. 152808371986693 ◽  
Author(s):  
Changchun Ji ◽  
Yudong Wang ◽  
Yafeng Sun
Keyword(s):  
Average Velocity ◽  
Fiber Diameter ◽  
Measurement Data ◽  
Melt Blowing ◽  
One Dimensional ◽  
Temperature Decay ◽  
Slot Die ◽  
The Common ◽  
The One ◽  
Peak Value

In order to decrease the fiber diameter and reduce the energy consumption in the melt-blowing process, a new slot die with internal stabilizers was designed. Using computational fluid dynamics technology, the new slot die was investigated. In the numerical simulation, the calculation data were validated with the laboratory measurement data. This work shows that the new slot die could increase the average velocity on the centerline of the air-flow field by 6.9%, compared with the common slot die. Simultaneously, the new slot die could decrease the back-flow velocity and the rate of temperature decay in the region close to the die head. The new slot die could reduce the peak value of the turbulent kinetic energy and make the fiber movements more gradual. With the one-dimensional drawing model, it proves that the new slot die has more edge on the decrease of fiber diameter than the common slot die.

On inference in a one-dimensional mosaic and an M/G/∞ queue

1985 ◽  
Vol 17 (01) ◽  
pp. 210-229
Author(s):  
Peter Hall
Keyword(s):  
Poisson Process ◽  
Segment Length ◽  
One Dimensional ◽  
Estimation Procedures ◽  
The One

Suppose segments are distributed at random along a line, their locations being determined by a Poisson process. In the case where segment length is fixed, we compare efficiencies of several different estimates of Poisson intensity. The case of random segment length is also considered, and there we study estimation procedures based on empiric properties. The one-dimensional mosaic may be viewed as an M/G/∞ queue.

A characterization of the Poisson process

1974 ◽  
Vol 11 (1) ◽  
pp. 72-85 ◽  
Author(s):  
S. M. Samuels
Keyword(s):  
Poisson Process ◽  
Renewal Process ◽  
Poisson Processes ◽  
Renewal Processes ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
Complete Proof ◽  
Necessary And Sufficient

Theorem: A necessary and sufficient condition for the superposition of two ordinary renewal processes to again be a renewal process is that they be Poisson processes.A complete proof of this theorem is given; also it is shown how the theorem follows from the corresponding one for the superposition of two stationary renewal processes.

Macroeconomic conditions are only an illusion, not the solution, to firm sustainability: unveiling the new dimension of stakeholder well-being

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zahid Irshad Younas ◽  
Mahvesh Khan ◽  
Mamdouh Abdulaziz Saleh Al-Faryan
Keyword(s):  
Well Being ◽  
Developed Countries ◽  
Macroeconomic Performance ◽  
Content Type ◽  
Macroeconomic Conditions ◽  
Us Economy ◽  
The Us ◽  
The Usa ◽  
Negative Impacts ◽  
The One

Purpose The purpose of the study is to explore the misconception that in developed countries, macroeconomic performance lead to sustainable firms or improves stakeholder well-being. The results may be the opposite or even worse. Design/methodology/approach This study examined this misconception using balanced panel data from 1,122 firms from different sectors of the US economy and data on macroeconomic performance from the World Bank. Findings The results of the one-step generalised method of moments indicate that most macroeconomic performance indicators had significant and negative impacts on firm sustainability and stakeholder well-being. Practical implications From a societal perspective, the results illustrate that the fruits of macroeconomic performance of the US economy do not reach stakeholders through firms’ sustainability. Thus, linking the economy’s macroeconomic performance with firm sustainability is vital for sustainably uplifting society and for stakeholder well-being. Originality/value From a policy perspective, this study reveals that the greater focus on macroeconomic performance in the USA over the past decades has resulted in lower firm sustainability because of the malfunctioning of social, economic, environmental and governance factors. This has negatively influenced stakeholder well-being in the country.

PSYCHOLOGICAL BASIS OF CONVICTED WOMEN IN DETENTION PLACES WITH CHILDREN: INTERNATIONAL EXPERIENCE

2021 ◽  
pp. 110-116
Author(s):  
Светлана Станиславовна Пиюкова
Keyword(s):  
Great Britain ◽  
Family Reunification ◽  
Research Data ◽  
Correctional Institution ◽  
Correctional Institutions ◽  
Mothers And Children ◽  
Mother And Child ◽  
The Usa ◽  
The One

Статья посвящена рассмотрению психологических основ совместного пребывания осужденных женщин с детьми в отделениях матери и ребенка пенитенциарных учреждений различных стран. Раскрывается значение регулярных контактов осужденной женщины со своим ребенком на протяжении всего срока ее пребывания в исправительном учреждении. Характеризуется влияние ограничения контактов с матерями, находящимися в местах лишения свободы, на развитие психики их детей. Авторами статьи обосновывается роль поддержания отношений между матерями и детьми как одного из факторов, способствующих увеличению вероятности успешного воссоединения семей после освобождения женщин из мест лишения свободы. Рассматриваются существующие в настоящее время в международной пенитенциарной практике решения по созданию условий для содержания осужденных женщин с детьми в исправительных учреждениях. Характеризуются задачи отделений матери и ребенка, а также приводятся примеры из практики их организации в пенитенциарных системах США, Канады, Великобритании, Новой Зеландии, Германии и других стран. Приводятся данные исследований, свидетельствующие об эффективности работы отделений матери и ребенка. Анализируются аргументы сторонников и противников содержания осужденных женщин с детьми в исправительных учреждениях. Обосновывается тезис о необходимости достижения баланса в удовлетворении потребностей ребенка, с одной стороны, и организации условий для совместного содержания осужденных женщин с детьми в исправительных учреждениях, принимая во внимание вопросы безопасности и серьезность правонарушений со стороны матери. The article is devoted to the examination of the psychological foundations of the joint stay of convicted women with children in the mother and child wards of penitentiary institutions in different countries. The significance of regular contacts between a convicted woman and her child throughout the entire period of her stay in a correctional institution is revealed. The influence of limiting contacts with mothers in prison on the development of the psyche of their children is characterized. The authors of the article substantiate the role of maintaining relations between mothers and children as one of the factors contributing to an increase in the likelihood of successful family reunification after the release of women from prison. The author considers the solutions currently existing in international penitentiary practice to create conditions for the detention of convicted women with children in correctional institutions. The tasks of mother and child departments are characterized, and examples from the practice of their organization in the penitentiary systems of the USA, Canada, Great Britain, New Zealand, Germany and other countries are given. Research data showing the effectiveness of the work of the mother and child departments are presented. The arguments of supporters and opponents of keeping convicted women with children in correctional institutions are analyzed. The thesis is substantiated that it is necessary to achieve a balance in meeting the needs of the child, on the one hand, and to organize conditions for the joint detention of convicted women with children in correctional institutions, taking into account the issues of safety and the seriousness of offenses on the part of the mother.

Survival of fish passing downstream at a small hydropower facility

2018 ◽  
Vol 69 (12) ◽  
pp. 1870 ◽  
Author(s):  
Stephen V. Amaral ◽  
Benjamin S. Coleman ◽  
Jenna L. Rackovan ◽  
Kelly Withers ◽  
Benjamin Mater
Keyword(s):  
Mississippi River ◽  
River Flow ◽  
Survival Rates ◽  
Fish Populations ◽  
Negative Effects ◽  
Small Hydropower ◽  
The Usa ◽  
Pass Through ◽  
Hydro Project ◽  
Total Project

Hydropower dams can negatively affect upstream and downstream migratory fish populations in many ways, such as blocking access to upstream habitats and causing injuries or mortality during downstream passage. For downstream passage at projects in the USA, federal regulators and agencies responsible for oversight of hydropower facilities typically require assessment studies and mitigation to address negative effects, with a primary goal of minimising fish impingement and turbine entrainment and mortality. So as to assess the effects of downstream passage of fish populations at a unique, small hydro project on the Mississippi River, impingement and entrainment rates, Oberymeyer gate passage, spillway gate passage, turbine survival, and total downstream passage survival were estimated. It was determined that 85% of fish passing downstream at the project would be small enough to pass through the bar spacing of the trash racks and 15% would be physically excluded. When 55% of river flow enters the turbine intake channel, the total project survival rates were estimated to be 77.3% with an Obermeyer gate bypass rate of 10 and 96.6% with a gate bypass rate of 90%. Therefore, any effects on local fish populations resulting from the operation of the project are expected to be negligible and inconsequential on the basis of expected survival rates for the range and probability of river flows occurring at the project.

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