bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling of Gusts for the Determination of Extreme Loads of Pitch Regulated Wind Turbines
Authors: Bierbooms Wim 
Published: August 2004

A probabilistic method has been applied to determine the extreme response of pitch regulated wind turbines caused by wind speed gusts. It is assumed that the extreme loading for pitch regulated turbines is caused by gusts with an extreme rise time rather than an extreme gust amplitude. A special kind of wind field simulation, so-called constrained stochastic simulation, is dealt with in order to generate the desired gusts. It can be stated that the stochastic gusts produced in this way are, in a statistical sense, not distinguishable from gusts selected from a (very long) time series. The theoretical mean gust shape, as well as the probability of occurrence of gusts, has been verified by measurements for modest gusts; but not, as yet, severe gusts. For the reference turbine the 50-year blade root flapping moment turned out to be much higher than the response on the IEC operating gust; this should be verified for commercial turbines. The method is formulated in such a way that it can easily be implemented in state-of-the-art design packages for wind turbine design as used by the industry. It should be possible to extend the method to a spatial gust. The proposed more accurate description of extreme loading will enable wind turbine manufacturers to build more reliable and optimised wind turbines.
Designing Marine Reserves for Fishery Management
Authors: Meester Geoffrey A. , Mehrotra Anuj , Ault Jerald S. , Baker Edward K. 
Published: August 2004

Recent reports have raised serious concerns about the rapid declines of historically productive marine fishery resources and the degradation of essential fish habitats. This global crisis has spurred development of innovative management strategies to rebuild depleted fisheries and marine ecosystems. One highly touted strategy involves the design and creation of marine reserves (areas off limits to extractive uses) to rebuild fisheries and conserve marine biodiversity. In this paper, we propose an integrated sequence of methodologies that provides an objective, quantitative framework for the design of marine reserves in spatially heterogeneous coastal ocean environments. The marine reserve designs proposed here satisfy the multiple, often-conflicting criteria of disparate resource user groups. This research is the first attempt to explicitly explore the trade-off between the conservation goals of fishery management and coral reef protection and the consumptive interests of commercial and recreational fishing fleets. The spatial distribution and size abundance of reef fish stocks throughout the Florida Keys coral reef ecosystem were estimated from a database consisting of more than 18,000 visual samples taken from 1979 to 2002. These distributions of multispecies abundance and biomass, in conjunction with a geographic database of coral reef habitats, are used to demonstrate an integer goal programming methodology for the design of networks of marine reserves, called plans. Once multiple plans are proposed, a simulation model is used to assess the effects of reserve size and shape on select Florida Keys reef fish populations under dynamic spatial and temporal conditions.
Modeling the Impact of Merging Capacity in Production-Inventory Systems
Authors: Iyer Ananth V. , Jain Apurva 
Published: August 2004

We model two separate, decentralized systems, each consisting of a warehouse and a production capacity. The demand processes experienced by the systems have different variabilities. The two decentralized systems consider an agreement to pool their production capacities. We examine the impact of the pooling of capacity on inventory costs under two operating rules: (i) the orders from the two warehouses are treated in a first-come–first-served manner, and (ii) the orders from the lower-variability warehouse are given nonpreemptive priority. We examine this issue using an analytical model that integrates base-stock inventory models with queuing models for the production capacity. The higher-variability demand is modeled as a hyperexponential renewal process, and the lower-variability demand is modeled as a Poisson process. In case of pooled capacity, the arrival process at the production queue is the superposition of the two processes. We prove conditions under which the first-come–first-served operating rule will fail to achieve a Pareto improvement over the separate systems because it would increase inventory cost at the lower-variability warehouse. We then show cases under which the high-variability warehouse will see a reduction in inventory cost over the split system even if it accepts lower priority.
Campaign Planning and Scheduling for Multiproduct Batch Operations with Applications to the Food-Processing Industry
Authors: Rajaram Kumar , Karmarkar Uday S. 
Published: August 2004

We analyze planning and scheduling of multiproduct batch operations in the food-processing industry. Such operations are encountered in many applications including manufacturing of sorbitol, modified starches, and specialty sugars. Unlike discrete manufacturing, batch sizes in these operations cannot be set arbitrarily, but are often determined by equipment size. Multiple batches of the same product are often run sequentially in “campaigns” to minimize setup and quality costs. We consider a multiproduct, single-stage, single-equipment batch-processing scheme and address the problem of determining the timing and duration of product campaigns to minimize average setup, quality, and inventory holding costs over a horizon. We formulate the deterministic, static version of this problem over an infinite horizon. We show that, in general, a feasible, finite, cyclic solution may not exist. We provide sufficient conditions for the existence of a finite cycle, use single-product problems to provide lower bounds on the costs for the multiproduct problem, and use them to test heuristics developed for this problem. Next, we modify this formulation to incorporate fixed cycles that may be necessary due to factors such as product obsolescence, perishability, or contracts with customers. We do this by allowing for disposal of excess stock so that finite cycles are always feasible, though they might not be optimal; we also develop bounds and heuristic solution procedures for this case. These methods are applied to data from a leading food-processing company. Our results suggest that our methods could potentially reduce total annual costs by about 7.7% translating to an annual savings of around $7 million.
Investigation of correlations and milking parameter distribution on cattle farms in eastern Croatia
Authors: Mijić P. , Knežević I. , Baban M. , Domaćinović M. , Rimac D. 
Published: August 2004

Recently secondary cattle selection traits have been given more attention in developed cattle breeding countries in establishing a selection index. In this way, milking traits have acquired a prominent place. This paper aimed to determine coefficients of correlation and regression between a number of milking traits, that could be helpful in establishing a selection index for breeding bulls and their dams. A further goal was to determine the distribution of milking parameters. The data of 303 Holstein Friesian and 235 Simmental cows were analysed. The results showed that in both cow breeds correlations existed between milk yield and average milk flow (0.39 and 0.49), as well as between milk yield and milking time (0.53 and 0.35). Negative correlations were found between average milk flow and milking time (-0.49 and -0.56). For the Holstein Friesian breed, 67.0% of the cows had a total milk flow in the range of 1.61 to 3.60 kg/min, whereas in the Simmental breed 72.2% of the cows had a total milk flow of 2.40 kg/min. The milk flow rate can be indirectly affected by selecting cows with higher milk production. The definition of an optimal milk flow rate and the determination of breeding goals for milking traits will lead to faster progress in milking trait improvement and an easier choice of quality breeding bulls and dams.
Substitution analysis of seedling stage copper tolerance in wheat
Authors: Bálint A. F. , Kovács G. , Börner A. , Galiba G. , Sutka J. 
Published: August 2004

The relatively copper-tolerant wheat variety Chinese Spring (recipient), the copper-sensitive variety Cappelle Desprez (donor) and their substitution lines were screened for copper tolerance in a soil pot experiment under artificial growth conditions. Chromosomes 5A, 5B, 5D and 7D of Cappelle Desprez significantly decreased the copper tolerance of the recipient variety to varying extents. By contrast, the 6B and 3D chromosomes significantly increased the copper tolerance of Chinese Spring, suggesting that a wide range of allelic differences could be expected between wheat genotypes for this character. The significant role of homologous group 5 in copper tolerance was confirmed by testing wheat-rye substitution lines. The substitution of rye chromosome 5R (5R/5A substitution line) into a wheat genetic background significantly increased the copper tolerance of the recipient wheat genotype. The results suggest that chromosomes 5R and 5A probably carry major genes or gene complexes responsible for copper tolerance, and that the copper tolerance of wheat can be improved through the substitution of a single chromosome carrying the responsible genes. At the same time, it is also possible that the effect of homologous group 5 is not specific to copper tolerance, but that the genes located on these chromosomes belong to a general stress adaptation (frost, cold, vernalisation requirements, etc.) complex, which has already been detected on this chromosome. To answer this question further studies are needed to determine the real effect of these chromosome regions and loci on copper tolerance.
What makes Hungarian SMEs perform poorly?
Authors: Major I. 
Published: August 2004

Small and medium-sized enterprises (SMEs) have been the target of supportive government policies since economic transformation began in Hungary although the birth of a strong and healthy layer of SMEs has not been observed in the country up to now. In this article the issue of why this has not happened is addressed. Empirical evidence suggested that Hungarian SMEs are not usually driven by the corporate values of Max Weber’s “protestant ethics”; instead, they aim at short-term financial enrichment. Hungarian SMEs cannot usually “climb the ladder” and turn into large enterprises – indeed, their survival period is relatively short.
Nickell (1996) argued that (total factor) productivity rather than profitability would reflect a company’s efficiency level. Using frontier production and frontier profit functions there is an attempt here to prove that “technical (or allocative) efficiency” and “profit efficiency” both have a distinct role to play in explaining a firm’s economic performance; and by applying limited information maximum likelihood models of SME profit gaps it will be shown that cost inefficiencies and unfavourable market conditions — alongside the inefficient allocation of factors of production — inevitably lead to the fairly low level of SME profitability.
The most important finding of the analysis is that employment has been a crucial factor in explaining the profit deviation of companies. Building on the results of Köllő (2001) the article argues that SMEs regard labour as flexible stock. Companies will seek out new labour if they find new market opportunities — but until these appear, they tend to remain in the arena of diminishing returns, this being the easiest way for them to maximise profits. Downgraded production activities do not attract substantial external financing. Yet a lack of financial resources when new market opportunities do emerge will prevent an SME from exploiting the chance.
An early mainstream economist from Hungary: István Varga (1897–1962)
Authors: Majoros K. 
Published: August 2004

The study introduces a Hungarian economic thinker, István Varga*, whose valuable activity has remained unexplored up to now. He became an economic thinker during the 1920s, in a country that had not long before become independent of Austria. The role played by Austria in the modern economic thinking of that time was a form of competition with the thought adhered to by the UK and the USA. Hungarian economists mainly interpreted and commented on German and Austrian theories, reasons for this being that, for example, the majority of Hungarian economists had studied at German and Austrian universities, while at Hungarian universities principally German and Austrian economic theories were taught.István Varga was familiar not only with contemporary German economics but with the new ideas of Anglo-Saxon economics as well — and he introduced these ideas into Hungarian economic thinking. He lived and worked in turbulent times, and historians have only been able to appreciate his activity in a limited manner. The work of this excellent economist has all but been forgotten, although he was of international stature.After a brief summary of Varga’s profile the study will demonstrate the lasting influence he has had in four areas — namely, business cycle research and national income estimations, the 1946 Hungarian stabilisation program, corporate profit, and consumption economics — and will go on to summarise his most important achievements.
Economic bases of international mechanisms on climate change
Authors: Siskos E. 
Published: August 2004

Neither the UN Framework Convention on Climate Change nor the Kyoto Protocol nor other international agreements aiming at the establishment of legal and economic — and also sustainable — world development mechanisms seeking to achieve a harmony between economic growth and preservation of the environment have led to any reduction in annual increases of anthropogenic greenhouse gas emissions.
This is due, to a considerable extent, to the initially non-complete principles of evaluation regarding the different responsibilities of countries in connection with atmosphere pollution. The aforementioned principles are based on total emissions volumes. However, what might be seen as more justified in any estimation of permissible pollution levels is, within potential international trading of volume quotas for the rights to carbon dioxide emissions, an account of the intensity of pollution per square kilometer of surface area and the absorption potential of forests and other green plantations present in every country.
Book Reviews
Authors: Csaba László , Sergi Bruno S. , Fridberga Kristine 
Published: August 2004

Szentes, Tamás: World Economics. Comparative Theories and Methods of International and Development Economics (Budapest: Akadémiai Kiadó, 2002, 462 pp.) Kozlov, Vladimir A. (ed. by E. McClarnand MacKinnon): Mass Uprisings in the USSR: Protest and Rebellion in the Post-Stalin Years (New York: Armonk and London: M. E. Sharpe, 2002, 351 pp.) Gilpin, Robert: Global Political Economy: Understanding the International Economic Order (Princeton: Princeton University Press, 2001, 423 pp.)
On the covering radius of small codes
Authors: Kéri G. , Östergård P. R. J. 
Published: August 2004

The minimum number of codewords in a code with t ternary and b binary coordinates and covering radius R is denoted by K(t,b,R). In this paper, necessary and sufficient conditions for K(t,b,R)=M are given for all M = 5. By the help of generalized s-surjective codes, we develop new methods for finding bounds for K(t,b,R). These results are used to prove the equality K(9,0,5)=6 as well as some new lower bounds such as K(2,7,3) =7, K(3,6,3)=8, K(5,3,3)=8, and K(9,0,4)=9. Some bounds for (nonmixed) quaternary codes are also obtained.
Strongly almost summable difference sequences of order m defined by a modulus
Authors: Et Mikail 
Published: August 2004

The purpose of this paper is to introduce the space of sequences that are ?r-strongly almost summable with respect to a modulus function. We give some relations related to these sequence spaces. We also show that the space s(?r)of ?r-almost statistically convergent sequences may be represented as a [c,f] (?r)space.
Prenatal Care Initiation and Exposure to Teratogenic Medications
Authors: Winterstein Almut G. , Wang Yanning , Smolinski Nicole E. , Thai Thuy N. , Ewig Celeste , Rasmussen Sonja A. 
Published: February 2024

ImportanceWith new legal abortion restrictions, timing of prenatal care initiation is critical to allow for discussion of reproductive options among pregnancies exposed to teratogenic medications.ObjectiveTo investigate the prevalence of prenatal exposure to teratogenic medications and prenatal care initiation across gestational weeks.Design, Setting, and ParticipantsThis descriptive, population-based cross-sectional study used health encounter data from a national sample of individuals with employer-sponsored health insurance. A validated algorithm identified pregnancies among persons identifying as female that ended with a live or nonlive outcome between January 2017 and December 2019. Data were analyzed from December 2022 to December 2023.ExposuresPrenatal exposure to any of 137 teratogenic medications, measured via pharmacy and medical claims. Measurement of prenatal care initiation was adapted from the Children’s Health Care Quality Measures.Main Outcomes and MeasuresPrevalence of prenatal exposure to teratogens and prenatal care initiation by gestational week. Timing of prenatal teratogenic exposure was compared with timing of prenatal care initiation and legal abortion cutoffs.ResultsAmong 639 994 pregnancies, 472 472 (73.8%; 95% CI, 73.7%-73.9%) had a live delivery (mean [SD] age, 30.9 [5.4] years) and 167 522 (26.2%; 95% CI, 26.1%-26.3%) had a nonlive outcome (mean [SD] age, 31.6 [6.4] years). Of pregnancies with live deliveries, 5.8% (95% CI, 5.7%-5.8%) were exposed to teratogenic medications compared with 3.1% (95% CI, 3.0%-3.2%) with nonlive outcomes. Median time to prenatal care was 56 days (IQR, 44-70 days). By 6 weeks’ gestation, 8186 pregnancies had been exposed to teratogenic medications (25.2% [95% CI, 24.7%-25.7%] of pregnancies exposed at any time during gestation; 1.3% [95% CI, 1.3%-1.3%] of all pregnancies); in 6877 (84.0%; 95% CI, 83.2%-84.8%), prenatal care was initiated after 6 weeks or not at all. By 15 weeks, teratogenic exposures had occurred for 48.9% (95% CI, 48.4%-49.5%) of all teratogen-exposed pregnancies (2.5% [2.4-2.5] of all pregnancies); prenatal care initiation occurred after 15 weeks for 1810 (16.8%; 95% CI, 16.1%-17.5%) with live deliveries and 2975 (58.3%; 95% CI, 56.9%-59.6%) with nonlive outcomes. Teratogenic medications most used within the first 15 gestational weeks among live deliveries included antiinfectives (eg, fluconazole), anticonvulsants (eg, valproate), antihypertensives (eg, lisinopril), and immunomodulators (eg, mycophenolate). For nonlive deliveries, most antihypertensives were replaced by vitamin A derivatives.Conclusions and RelevanceIn this cross-sectional study, most exposures to teratogenic medications occurred in early pregnancy and before prenatal care initiation, precluding prenatal risk-benefit assessments. Prenatal care commonly occurred after strict legal abortion cutoffs, prohibiting consideration of pregnancy termination if concerns about teratogenic effects arose.
Amblyopia Care Trends Following Widespread Photoscreener Adoption
Authors: Stults Cheryl D. , Liang Su-Ying , Wilcox Joseph , Nyong’o Omondi L. 
Published: February 2024

ImportanceAmblyopia can result in permanent vision loss if not properly treated before age 7 years. In 2017, the US Preventive Services Task Force recommended that vision screening should occur at least once in all children aged 3 to 5 years to detect amblyopia.ObjectiveTo understand trends and factors associated with screening, referral, or diagnosis of amblyopia before and after photoscreening expansion across a relatively large health care system in late 2017.Design, Setting, and ParticipantsThis is a retrospective cohort study of electronic health record data from patients with a well child care visit at approximately age 3 years (ages 2.75-3.25 years) in a relatively large, multispecialty group practice in Northern California and linked census data between 2015 and 2022. Data were extracted and analyzed from October 2022 through August 2023.ExposuresPatient sex, race and ethnicity, immunization records, previous well child care visits, and census-level median household income.Main Outcomes and MeasuresVision screening, pediatric ophthalmology referral, or amblyopia diagnosis, compared using adjusted odds ratios (AORs).ResultsThe study included 2015-2017 data from 23 246 patients aged 3 years with at least 1 well child care visit (11 206 [48.2%] female) compared with 2018-2022 postexpansion data from 34 281 patients (16 517 [48.2%] female). The screening rate increased from 5.7% (424 of 7505) in 2015 to 72.1% (4578 of 6354) in 2022. The referral rate increased from 17.0% (1279 of 7505) in 2015 to 23.6% (1836 of 7792) in 2018. The diagnosis rate was 2.7% (200 of 7505) in 2015, peaked at 3.4% (263 of 7792) in 2018, and decreased to 1.4% (88 of 6354) in 2022. Compared with White patients, patients who were Asian, Black, or Hispanic were less likely to be screened (Asian: AOR, 0.80; 95% CI, 0.72-0.88; Black: AOR, 0.71; 95% CI, 0.53-0.96; Hispanic: AOR, 0.88; 95% CI, 0.80-0.97). Compared with White patients, patients who were Asian or Hispanic were more likely to be referred (Asian: AOR, 1.49; 95% CI, 1.36-1.62; Hispanic: AOR, 1.32; 95% CI, 1.18-1.48) and were more likely to be diagnosed (Asian: AOR, 1.29; 95% CI, 1.07-1.56; Hispanic: AOR, 1.67; 95% CI, 1.33-2.11).Conclusions and RelevanceIn this study, increased availability of photoscreeners was associated with an increase in overall rates of vision screening for children aged 3 years in a relatively large health care system. Given that US rates of visual impairment are predicted to increase, additional targeted interventions would be needed to address remaining disparities in amblyopia care along patient- and clinician-level factors.
Aging as a Consequence of the Adaptation–Maladaptation Dilemma
Authors: Lissek Thomas 
Published: February 2024

AbstractIn aging, the organism is unable to counteract certain harmful influences over its lifetime which leads to progressive dysfunction and eventually death, thus delineating aging as one failed process of adaptation to a set of aging stimuli. A central problem in understanding aging is hence to explain why the organism cannot adapt to these aging stimuli. The adaptation–maladaptation theory of aging proposes that in aging adaptation processes such as adaptive transcription, epigenetic remodeling, and metabolic plasticity drive dysfunction themselves over time (maladaptation) and thereby cause aging‐related disorders such as cancer and metabolic dysregulation. The central dilemma of aging is thus that the set of adaptation mechanisms that the body uses to deal with internal and external stressors acts as a stressor itself and cannot be effectively counteracted. The only available option for the organism to decrease maladaptation may be a program to progressively reduce the output of adaptive cascades (e.g., via genomic methylation) which then leads to reduced physiological adaptation capacity and syndromes like frailty, immunosenescence, and cognitive decline. The adaptation–maladaptation dilemma of aging entails that certain biological mechanisms can simultaneously protect against aging as well as drive aging. The key to longevity may lie in uncoupling adaptation from maladaptation.