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In a recent paper, Pinto and Mabert [5] presented a lot-sizing rule and an improvement procedure for the joint lot-sizing problem with zero setup costs. We show that this procedure often yields infeasible schedules. We also present and discuss two interesting properties of the joint lot-sizing problem with zero setup costs. A numerical example to illustrate the second property is provided. 相似文献
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A model is presented that yields optimal production rates for a firm producing a contracted order. The model is unique in that it considers the influence of production rate and learning on total program cost. An application to the specific characteristics of two military production programs is presented. As demonstrated by the application, models of this type may be used as decision-making tools when negotiating the cost impact of contract modifications. 相似文献
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Euthanasia and assisted suicide are subject to an ongoing debate and discussed with various aspects. Because physicians are in a profession closely related to euthanasia, their attitudes toward this subject are significant. Thus, research intending to explore their opinions is carried out in many countries. In this study, opinions of the physicians regarding euthanasia's definition, contents, legal aspects, and acceptable conditions for its application are addressed. The questionnaire was given to 949 physicians, more than 1% of the total working in Turkey. Of the physicians who participated in the study, 49.9% agreed with the opinion that euthanasia should be legal in certain circumstances. In addition, 19% had come across a euthanasia request and the majority of physicians (55.9%) believed that euthanasia is applied secretly in the country despite the prohibitory legislation. In conclusion, the authors infer from the study itself and believe that euthanasia should be legal in certain circumstances and that the subject, which is not in the agenda of the Turkish population, should continue to be examined. 相似文献
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Visceral adiposity index is associated with premature ejaculation inversely: a cross-sectional study
Suleyman Sami Cakir Levent Ozcan Huseyin Besiroglu Murat Dursun Emre Can Polat Alper Otunctemur 《The aging male》2018,21(3):206-210
Objective: Visceral adiposity index (VAI) is a novel indicator for the assessment of visceral obesity. In this study, we aimed to evaluate the relationship between VAI and premature ejaculation (PE).Materials and method: A total of 300 men were included in the study. Hundred and fifty men with PE and 150 men without PE (control). All men were evaluated for PE by premature ejaculation diagnostic tool (PEDT). VAI levels were calculated using body mass index (BMI), high density lipoprotein and triglyceride (TG) levels.Results: Mean age of the study groups was 34.3?±?5.2 (30–60) years and the mean age of the controls were 35.9?±?5.3 (30–60) years. The men with PE had lower BMI, TG levels, waist circumference (WC) and higher high-density lipoprotein-cholesterol (HDL-C) levels. Mean VAI level was 4.13?±?0.7 in study group and 5.72?±?1.6 in control group, respectively. VAI levels were statistically higher in men without PE (p?.001).Discussion: Our cross-sectional study demonstrated a negative correlation between VAI and PE. VAI is superior index for the evaluation and calculation the relationship between obesity and PE. 相似文献
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In this paper, we study the class of inflated modified power series distributions (IMPSD) where inflation occurs at any of the support points. This class include among other the generalized Poisson, the generalized negative binomial, the generalized logarithmic series and the lost games distributions. We give expressions for the moments, factorial moments and central moments of the IMPSD. The maximum likelihood estimation of the parameters of the IMPSD and the variance – covariance matrix of the estimators is obtained. We derive these estimators and their information matrices for mentioned above particular members of IMPSD class. The second part of this paper deals with the distribution of sum of independent and identically distributed random variables taking values s, s+1. s + 2, …, s ≥ 0, with modified power series distributions inflated at the point s. 相似文献
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The majoritarian compromise is majoritarian-optimal and subgame-perfect implementable 总被引:2,自引:0,他引:2
It is shown that the Majoritarian Compromise of Sertel (1986) is subgame-perfect implementable on the domain of strict preference profiles, although it fails to be Maskin-monotonic and is hence not implementable in Nash
equilibrium. The Majoritarian Compromise is Pareto-optimal and obeys SNIP (strong no imposition power), i.e. never chooses a strict majority's worst candidate. In fact, it is “majoritarian approving”
i.e. it always picks “what's good for a majority” (alternatives which some majority regards as among the better “effective”
half of the available alternatives). Thus, being Pareto-optimal and majoritarian approving, it is majoritarian-optimal. Finally, the Majoritarian Compromise is measured against various criteria, such as consistency and Condorcet-consistency.
Received: 31 January 1995/Accepted: 22 July 1998 相似文献
8.
Murat Iyigun 《Journal of population economics》2005,18(2):301-321
This paper explores the role of geography in early development. It presents a model where the odds of survival are higher
in geographically favorable regions. In such regions, higher life expectancy prompts parents to devote more of their resources
to old-age consumption and enables them to invest relatively more in the quantity and quality of their offspring. Investment
in education, together with population growth, helps geographically-favorable economies to attain high levels of a more educated
population that is necessary for sustained economic growth. The empirical evidence is generally supportive of the view that
geographic attributes influenced regional population levels in Europe and its colonial offshoots around 1500 A.D. and that
they affected population levels and educational attainment in low-income countries of the 1990s.
For useful comments and suggestions I thank the editor, two anonymous referees, Daron Acemoglu, Ann Carlos, Phil Graves, Naci
Mocan, Oded Stark, seminar participants at the University of Colorado at Boulder, the University of Colorado at Denver, and
the 2002 Royal Economic Society Annual Conference. I owe a special debt of gratitude to my advisor Herschel Grossman who passed
away in October 2004 after leaving his mark on many of us in the profession. The standard disclaimer applies.
Responsible editor: Alessandro Cigno. 相似文献
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The mixture distribution models are more useful than pure distributions in modeling of heterogeneous data sets. The aim of this paper is to propose mixture of Weibull–Poisson (WP) distributions to model heterogeneous data sets for the first time. So, a powerful alternative mixture distribution is created for modeling of the heterogeneous data sets. In the study, many features of the proposed mixture of WP distributions are examined. Also, the expectation maximization (EM) algorithm is used to determine the maximum-likelihood estimates of the parameters, and the simulation study is conducted for evaluating the performance of the proposed EM scheme. Applications for two real heterogeneous data sets are given to show the flexibility and potentiality of the new mixture distribution. 相似文献