Choice Of Time Period Research Articles

Precipitation and temperature timings underlying bioclimatic variables rearrange under climate change globally.

Modeling how climate change may affect the potential distribution of species and communities typically utilizes bioclimatic variables. Distribution predictions rely on the values of the bioclimatic variable (e.g., precipitation of the wettest quarter). However, the ecological meaning of most of these variables depends strongly on the within-year position of a specific climate period (SCP), for example, the wettest quarter of the year, which is often overlooked. Our aim was to determine how the within-year position of the SCPs would shift (SCP shift) in reaction to climate change in a global context. We calculated the deviations of the future within-year position of the SCPs relative to the reference period. We used four future time periods, four scenarios, and four CMIP6 global climate models (GCMs) to provide an ensemble of expectations regarding SCP shifts and locate the spatial hotspots of the shifts. Also, the size and frequency of the SCP shifts were subjected to linear models to evaluate the importance of the impact modeler's decision on time period, scenario, and GCM. We found ample examples of SCP shifts exceeding 2 months, with 6-month shifts being predicted as well. Many areas in the tropics are expected to experience both temperature and precipitation-related shifts, but precipitation-related shifts are abundantly predicted for the temperate and arctic zones as well. The combined shifts at the Equator reinforce the likelihood of the emergence of no-analogue climates there. The shifts become more pronounced as time and scenario progress, while GCMs could not be ranked in a clear order in this respect. For most SCPs, the modeler's decision on the GCM was the least important, while the choice of time period was typically more important than the choice of scenario. Future predictive distribution models should account for SCP shifts and incorporate the phenomenon in the modeling efforts.

Economic and functional efficiency of the digital platform of urban traffic control

The paper is devoted to the development of urban planning activities in the field of urban traffic control via the expedient economic methods for solving the problems of road congestion, in particular, using the tax on congestion. The present study includes a comprehensive analysis of economic factors and methods of economic regulation to address the issues related to traffic congestion in a modern city. It has been found that the total costs of the trip affect the individual decision concerning the method, time and route of the trip. The economic regulation of this allows the optimal value of traffic density to be achieved. The application of this approach in combination with other economic and urban-planning methods in the field of urban-planning regulation and transport planning enables to significantly reduce or completely eliminate the problem of traffic congestion on the main streets of the city. Consequently, a comprehensive economic approach to elimination of traffic congestion in Irkutsk has been developed. The effectiveness of investments in an IP video surveillance system and transport fixation is justified. The choice of time periods and sections of city roads for levying tax for maintaining good city roads is analyzed.

Variable Selection by sNML Criterion in Logistic Regression with an Application to a Risk-Adjustment Model for Hip Fracture Mortality

When comparing the performance of health care providers, it is important that the effect of such factors that have an unwanted effect on the performance indicator (eg. mortality) is ruled out. In register based studies randomization is out of question. We develop a risk adjustment model for hip fracture mortality in Finland by using logistic regression. The model is used to study the impact of the length of the register follow-up period on adjusting the performance indicator for a set of comorbidities. The comorbidities are congestive heart failure, cancer and diabetes. We also introduce an implementation of the minimum description length (MDL) principle for model selection in logistic regression. This is done by using the normalized maximum likelihood (NML) technique. The computational burden becomes too heavy to apply the usual NML criterion and therefore a technique based on the idea of sequentially normalized maximum likelihood (sNML) is introduced. The sNML criterion can be evaluated efficiently also for large models with large amounts of data. The results given by sNML are then compared to the corresponding results given by the traditional AIC and BIC model selection criteria. All three comorbidities have clearly an effect on hip fracture mortality. The results indicate that for congestive heart failure all available medical history should be used, while for cancer it is enough to use only records from half a year before the fracture. For diabetes the choice of time period is not as clear, but using records from three years before the fracture seems to be a reasonable choice.

Time‐varying trends in frost indicators in the U.S. Southern Great Plains

AbstractClimatic frost indicators, including the dates of the last spring frost (LSF), the dates of the first fall frost (FFF), and the length of the frost‐free season (FFSL), are critical factors in anthropogenic and natural ecosystem management and can be directly calculated from daily minimum temperatures. Daily minimum temperature from the Applied Climate Information System was used to determine long‐term trends of frost indicators across the U.S. Southern Great Plains. The results demonstrated statistically significant trends of earlier LSF in eastern Kansas, western and eastern Oklahoma, and eastern Texas from 1950 to 2017. However, significantly later FFF trends and longer FFSL trends were mainly identified in eastern Oklahoma and eastern Texas. Overall, the region was characterized by the trends toward earlier LSF, later FFF, and longer FFSL from 1950 to 2017. In addition, the choice of time period in the climatic time series played an important role in LSF, FFF, and FFSL trends. Furthermore, the results from the correlation analysis of LSF and FFF with multiple climate indices indicated that the increasing trends in the spring Arctic Oscillation (AO) were consistent with the earlier onset of spring in Kansas and Texas, and the fall Atlantic Multidecadal Oscillation (AMO) was positively correlated with the later FFF dates in Kansas.

Interest Rate Exposure of Volatility Portfolios

The authors assess the exposure of stock portfolios sorted by total volatility to interest rate risk and determine whether this nonequity risk can explain differences in risk and risk-adjusted returns between low- and high-volatility portfolios over a 25-year period for U.S. equities. They find that the addition of an interest rate risk factor to the four-factor model reveals a small but positive duration for low-volatility portfolios. However, this new factor fails to improve the explanatory power of the model for both low- and high-volatility portfolios and has no significant impact on the portfolios’ risk-adjusted return. The authors find that interest rate factor loadings are fairly robust across different specifications of the multifactor model for low-volatility portfolios but are unstable for high-volatility portfolios. For all volatility portfolios under study, the significance of the results is highly dependent on the choice of time period. <b>TOPICS:</b>Analysis of individual factors/risk premia, equity portfolio management, volatility measures

Policing economic crime in Russia: from Soviet planned economy to privatization

Gilles Favarel-Garrigues. Policing Economic Crime in Russia: From Soviet Planned Economy to Privatization. New York: Columbia University Press, 2011. 304 pp. Index. $60.00, cloth.This book examines the evolution of penal policy and the policing of in Russia between 1965 and 1995. It is an unorthodox, but fruitful, choice of time period. These thirty years represent an understudied slice of Russian history, marked by the stagnation, slowdown, and breakup of the Soviet system. Toward the end of the period, the Soviet Union was dissolved and Russia experienced a chaotic transformation of its social and political institutions. The author examines two questions. First, how were the funds allocated to the fight against economic crime actually used? Second, were the law enforcement agencies unable to control the rapidly changing forms of criminality in those years, or were they simply fitting in with the government's intention of fostering a re-birth of private enterprise?The author explores the intersection of morality, social norms, legal institutions, economic resources, and ideology, referring to a wide range of Western and Russian literature. His argument rests on a solid foundation of archival material, painstakingly gathered over several years, and data from a number of qualitative in-depth interviews. Favarel-Garrigues's qualitative research strategy is justified by the elusive nature of criminality and, of course, by his stated purpose: to analyze the changing nature of the policing of economic crime in a country where the understanding of economic behaviour has been distorted by Marxist-Leninist ideology. In the Soviet Union, criminality was perceived as a waning bourgeois phenomenon. However, reality did not conform to the ideological postulates. Some police officers felt that they were expected to clamp down on ordinary citizens who were simply striving to make a better life for themselves. individuals were driven to economic criminality, realizing that the only way to achieve economic improvement was to operate in the shadows of the official planned economy. All non-planned economic activities were despised by Soviet officialdom, as an Interior Ministry Report from 1961, quoted by Favarel-Garrigues, indicates:A resident of Sverdlovsk, aged fifty, unemployed and living in a detached house, who constructed a hothouse with lighting and a water supply on his plot of land in order to grow food and sell it in the market. …

Colonialism on display: Indigenous people and artefacts at an Australian agricultural show

This article offers a case study of the Brisbane Exhibition from its inception in 1876 through to the 1910s when its Aboriginal courts were among the event's major attractions. One of the largest agricultural shows in Australia and one of the oldest annual events in post-contact Queensland, the Brisbane show has been a central feature of the community's social life and has consistently attracted huge crowds. The choice of time period, which spans the late frontier and the early post-frontier eras, emphasises the importance of identifying absences as well as inclusions in tracing a history of Indigenous participation in and representation at agricultural shows. It facilitates an assessment of the significance of Aboriginal displays and performances to the Queensland government authorities who organised them and the predominantly white audiences who flocked to the exhibits. In the 1910s, Brisbane's annual show was the most important medium through which those authorities sought to convey to the general public a vision of Indigenous people as a compliant group who could be trained to be useful workers, were subject to segregative practices, but were reassuringly inculcated with aspects of the broader community's value system. Accounts of visitors' reactions to the Aboriginal exhibits suggest, however, that they may have been more interested in those items deemed 'exotic' and 'authentically Aboriginal' than those objects which represented the achievements of the reserve and mission system. How the Indigenous creators and participants who provided the content of the displays viewed their role at the Exhibition remains frustratingly elusive.

Statistical bias correction for daily precipitation in regional climate models over Europe

We design, apply, and validate a methodology for correcting climate model output to produce internally consistent fields that have the same statistical intensity distribution as the observations. We refer to this as a statistical bias correction. Validation of the methodology is carried out using daily precipitation fields, defined over Europe, from the ENSEMBLES climate model dataset. The bias correction is calculated using data from 1961 to 1970, without distinguishing between seasons, and applied to seasonal data from 1991 to 2000. This choice of time periods is made to maximize the lag between calibration and validation within the ERA40 reanalysis period. Results show that the method performs unexpectedly well. Not only are the mean and other moments of the intensity distribution improved, as expected, but so are a drought and a heavy precipitation index, which depend on the autocorrelation spectra. Given that the corrections were derived without seasonal distinction and are based solely on intensity distributions, a statistical quantity oblivious of temporal correlations, it is encouraging to find that the improvements are present even when seasons and temporal statistics are considered. This encourages the application of this method to multi-decadal climate projections.

Trends and Variability in U.S. Corn Yields Over the Twentieth Century

AbstractThe United States is currently responsible for 40%–45% of the world’s corn supply and 70% of total global exports [the U.S. Department of Agriculture–National Agricultural Statistics Service (USDA–NASS)]. Therefore, analyses of the spatial and temporal patterns of historical U.S. corn yields might provide insight into future crop-production potential and food security. In this study, county-level maize yield data from 1910 to 2001 were used to characterize the spatial heterogeneity of yield growth rates and interannual yield variability across the U.S. Corn Belt.Widespread decadal-scale changes in corn yield variability and yield growth rates have occurred since the 1930s across the Corn Belt, but the response has varied substantially with geographic location. Northern portions of the Great Plains have experienced consistently high interannual corn yield variability, averaging 30%–40% relative to the mean. Increasing usage of irrigation in Nebraska, Kansas, and Texas, since the 1950s, has helped boost yields by 75%–90% over rain-fed corn, creating a yield gap of 2–4 T ha−1 between irrigated and nonirrigated corn that could potentially be exploited in other regions. Furthermore, irrigation has reduced interannual variability by a factor of 3 in these same regions. A small region from eastern Iowa into northern Illinois and southern Wisconsin has experienced minimal interannual yield variability, averaging only 6%–10% relative to mean yields.This paper shows that the choice of time period used for statistical analysis impacted conclusions drawn about twentieth-century trends in corn yield variability. Widespread increases in yield variability were apparent from 1950 onward, but were not significant over the entire 1930–2001 period. There is also evidence that yield variability decreased from the early 1990s to 2001. Corn yield growth rates peaked at an annual-average rate of 3%–5% in the 1960s (124.5 kg ha−1 yr−1), but have steadily declined to a relative rate of 0.78% yr−1 (49.2 kg ha−1 yr−1) during the 1990s. A general inverse relationship between increasing corn yield and decreasing yield growth rates was noted after county-level yields reached 4 T ha−1, suggesting that widespread, significant increases in corn yield are not likely to take place in the future, particularly on irrigated land, without a second agricultural revolution.

The Regime Debate Revisted: A Sensitivity Analysis of Democracy's Economic Effect

Some studies find that democracy inhibits growth while other studies find that democracy facilitates growth. Which conclusion is correct? To help resolve this debate, a variety of sensitivity analyses is conducted to answer two basic questions. First, why has the literature yielded contradictory results? Secondly, how believable are these results? The existing contradictions can be explained by analysts' choice of time period, with democracy having a negative effect on growth in the 1960s, a positive effect in the 1980s and no effect at all in the 1970s and 1990s. More generally, however, it is shown here that the statistical significance of these findings varies radically depending upon which control variables one utilizes and how one measures both growth and democracy.

Chronos/Chroma: Yellow Figures in Proust's La Prisonnière and Bely's Petersburg

THE COMPAKATIST CHRONOS/CHROMA: YELLOW FIGURES IN PROUST'S LA PRISONNIÈRE AND BELY'S PETERSBURG Sabine Doran In the tradition ofBakhtin's "chronotope"1 (the Greek chronos, time, plus topos, place) I would like to propose the term "chromo-tope" (chroma = color). Whereas the chronotope functions as a time-marker, singling out time as the fourth dimension of space, the chromo-tope spaces out time by means of color. Through the consideration of a particular color, yellow , I aim to explore, in a series oftexts and visual images from the first half of the twentieth century, the convergence of time and color. I contend that yellow motifs function as time-markers during this period, and thus as chromo-topes. The choice oftime period is not an arbitrary one, since it is at this moment that yellow becomes an emblematic presence, a stigmatizing force that alternates between the Medieval and the Modern, East and West, inscribing itself under the signs of the "Yellow Star" (stigmatizing Jews) and the "Yellow Peril" (stigmatizing Asians).2 What I call a "chromo-tope" moves along the border of the historical and the aesthetic, without, however, involving questions ofintentionality . For chromo-topes imply an intrinsic displacement, a meaning recognizable only after the fact, as a reinscription, refiguration, or reconstruction . Thus it is not a matter of a yellow symbolism, because symbolism implies a certain conventionality or preexisting system of signification , an intention to activate a given semantic field. Chromo-topes function on the level ??figurai relations, that is, ofrelations that reveal how what is marked in yellow announces its own coming about. One could usefully compare what I mean by chromo-tope with Auerbachs notion offigura or "figurai realism." In his classic work Mimesis, Auerbach contrasts the "excessive abstraction" of symbol and allegory with the "realism" offigures: An event taken as a figure preserves its literal and historical meaning. It remains an event, does not become a mere sign. The Church Fathers, especially Tertullian, Jerome, Augustine, had successfully defended figurai realism, that is, the maintenance ofthe basic historical reality of figures, against all attempts at spiritually allegorical interpretation. (196)3 In the figurai interpretation, both chronology and reality are preserved. The figurai connection between events constitutes their historical meaning . Thus a "figurai realism" was seen by Christian authors such as Dante as a way to link Biblical figures to mundane events, so that those events or people, taken from the world in which he lived, became themselves figures of Christian ideas (e.g., conversion, salvation) without negating their historicity or their reality. More broadly speaking, then, "figurai realism" means that material or human events can receive an interpretation that is at once historical Vol. 28 (200V: 53 YELLOW FIQUKES IN PKOUSTANV BELY and tropological. This is in effect what I attempt to do with the color yellow in this essay: the materiality and historicity of yellow elements only come to the fore if they are viewed as figures, that is, as concrete manifestations of other equally concrete and historical events. An allegorical or symbolic interpretation ofyellow, though perhaps valid in some contexts, would annul the historical meaning that early twentiethcentury avant-garde writers intend (as well as obscure the significance of their technical procedures), in their effort to forge a new kind of realism, namely a "figurai realism" in which access to historical reality is achieved by charging seemingly random, mundane things or events with figurai force. As Auerbach writes of Proust: [He] presents individual days and hours from different periods, but the exterior events which are the determining factors in the destinies of the novel's characters during the intervening lapses of time are mentioned only incidentally, in retrospect or anticipation. The ends the narrator has in mind are not to be seen in them; often the reader has to supplement them. (547) To offer these "supplements" is the task set for this essay. We will follow a topography of yellow that is marked by historical, biographical, and political events, to explore how the materiality ofwriting (writing-paper, wall-paper, ink, pigments) is linked to the power of self-inscription. For yellow chromo-topes are not themselves visual or perceptible as such, but demonstrate...

Nominal Wage Rigidity and Real Wage Cyclicality

We discuss the ability of standard estimates of the correlation of wages and employment to measure the relative strength of aggregate demand and supply shocks, given that the choice of time period, deflator, and explanatory variables inherently biases the estimated cyclical coefficients toward identifying labor supply or demand. We determine that a closer look at the standard wage/labor correlation shows that it can neither provide information on the relative strength of supply and demand shocks, nor give an indication of the response of wages to aggregate demand shocks. Following this, we test the predictions of a neo-Keynesian model for the correlation of employment and wages using restrictions generated by the model to identify movements along or shifts in labor demand. Our results are consistent with the theory of nominal wage rigidity and we find no reason to reject the neo-Keynesian model based on the correlation of wages and employment.

Calculation of parameters estimation on combined model of destination, mode, route and time period choice in EMME/2 macro

Parameter estimation of combined models is a different problem as a practitioners of transportation. The transportation engineers who want to use the combined model have to understand the procedure of estimating parameters and its mathematical theory in detail. However, available software is not user friendly. This paper is carried out the parameter estimation of the model which combines the origin-destination, mode, route and time period of trips, and its implementation in EMME/2 Macro. As the result of this paper, we belive that the practitioners of transportation planning can be adjusted easily the parameters of combined model.

A Note on Nominal Wage Rigidity and Real Wage Cyclicality

We discuss the ability of standard estimates of the correlation of wages and employment to measure the relative strength of aggregate demand and supply shocks, given that the choice of time period, deflator, and explanatory variables inherently biases the estimated cyclical coefficients toward identifying labor supply or demand. We determine that a closer look at the standard wage/labor correlation shows that it can neither provide information on the relative strength of supply and demand shocks, nor give an indication of the response of wages to aggregate demand shocks. Following this, we test the predictions of a neo-Keynesian model for the correlation of employment and wages using restrictions generated by the model to identify movements along or shifts in labor demand. Our results are consistent with the theory of nominal wage rigidity and we find no reason to reject the neo-Keynesian model based on the correlation of wages and employment.

Optimal asset mix and its link to changing fundamental factors

T he optimal asset mix that maximizes overall return while minimizing risk depends critically on the assumed individual asset returns and their volatility over some extended period of time. In addition, crosscorrelations of returns are important. Generally, these summary statistics are based on some long-run historical experience (such as forty years), which tends to blur the impact of distinct economic environments that can last for eight to fifteen years. One important issue is the sensitivity of the optimal asset mix to the choice of time period. Another issue concerns the required shift in the optimal asset mix when it is funded by longerterm liabilities. Such funding necessitates accounting for the variability of the liabilities as well as asset returns. This issue is particularly relevant for insurance companies and pension funds, whose liabilities are both long-lived and sensitive to the general level of interest rates. This article analyzes the impact of changing fundamental factors and the impact of the variability of liabilities on the optimal asset mix.

Technology's Storytellers: Reweaving the Human Fabric

Technology's Storytellers documents the emergence of the history of technology as a coherent intellectual discipline. Based on an analysis of nearly 300 articles published in Technology and Culture, it proposes a mode of historical research as a communal rather than an individualistic endeavor -- looking for patterns of consensus in the authors' choice of time periods, geographical locations, and types of technology to study. It discusses the recurrent themes of the relationship between science and technology and the cultural ambience of technology, and examines the extent to which historians are moving away from a once pervasive ideology of autonomous technological progress.Co-published with the Society for the History of Technology.

Soil Moisture Deficits in South-Central Sweden

Soil moisture fluxes in forest and grassland soils were analyzed for a rather dry region in south-central Sweden in order to assess climatologically induced dryness variability. Time series were constructed, using a conceptual soil moisture model, optimised against neutron probe measurements. Data in a 105 yrs climatic record were used as driving variables. A method to deal with the inhomogeneity of the long precipitation record was developed. It was shown that large variations existed, not only between the median values, but even more for the range of the quartiles, depending on the choice of time period. The statistical distribution varied significantly even between the two 50 yrs series, where the latter showed larger fluctuations around the median caused by a trend towards increased amount of high summer soil moisture deficits. Estimates of the interannual variations of possible water deficit stress on vegetation were made. The only time (1883-1987) when there was a calculated risk for drought stress on the forest during four consecutive years was during 1973-1976. This might have increased the vulnerability to the threats of acidification. It was concluded that the use of standard- and return periods can hardly be justified as no sets of average conditions exists.

Nonlinear Analysis of GaAs MESFET Amplifiers, Mixers, and Distributed Amplifiers Using the Harmonic Balance Technique

The harmonic balance technique with Newton's method is used to analyze several forms of large-signal operation of GaAs MESFET's, including, for the first time, a multiple-device configuration. Computer programs for the study of the MESFET mixer, intermodulation distortion in MESFET amplifiers, and the large-signal analysis of the MESFET distributed amplifier are described and examples of analyses are given. Convergence properties are excellent, even for cases with a large number of error functions. The choice of time period for analysis, the number of sampling points required, and factors critical to convergence are discussed. Time sampling at much larger than the Nyquist rate does not significantly improve the accuracy and greatly increases the program's execution time.

Disclosure Regulations and the Cost of Capital

Due to the growth of publicly held corporations, the quality of corporate financial disclosure has become one of the most important concerns of the accounting profession and the Securities and Exchange Commission (SEC). This concern over the quality of financial disclosure has resulted in various disclosure regulations by the American Institute of Certified Public Accountants (AICPA) and the SEC. For example, effective 31 December 1970, the SEC required multi-product firms to report both the revenue and profit data by line-of-business in their 10-K reports filed with the commission on a periodic basis. In March 1976, the SEC amended regulation S-X via rule 3-17 which requires footnote (or other supplementary) disclosure to conventional historical cost financial statements of certain data restated on a current entry cost basis. The purpose of this paper is to investigate the impact of such disclosure regulations on the cost of capital of the affected firm. Specifically, this paper presents the results of an empirical investigation of the impact of the SEC's requirement to report by line-of-business on the cost of equity capital of the affected firms. The paper is organized as follows. Next section presents a discussion of the likely effects of disclosure regulations on the cost of equity capital and provides motivation for an empirical examination of the question. In order to conduct our empirical investigation, appropriate surrogates for the cost of equity capital are developed in the third section. The fourth section describes the selection of sample firms and the choice of time periods used in this study. Formulation of the test hypothesis, research methodology used and results obtained are discussed next. Last, a brief summary of the study is presented.