The analysis of bullwhip effect in a HMMS-type supply chain

The aim of the paper is to investigate the well-known bullwhip effect of supply chains. Control theoretic analysis of bullwhip effect is extensively analyzed in the literature with the Laplace transform. This paper tries to examine the effect for an extended Holt–Modigliani–Muth–Simon model. A two-stage supply chain (supplier–manufacturer) is studied with quadratic costs functional. It is assumed that both firms minimize the relevant costs. The order of the manufacturer is delayed with a known constant. Two cases are examined: supplier and manufacturer minimize the relevant costs decentralized, and a centralized decision rule. The question is answered, how to decrease the bullwhip effect.

The analysis of bullwhip effect in a HMMS-type supply chain

The aim of the paper is to investigate the well-known bullwhip effect of supply chains. Control theoretic analysis of bullwhip effect is extensively analyzed in the literature with Laplace transform. This paper tries to examine the effect for an extended Holt-Modigliani-Muth-Simon model. A two-stage supply chain (supplier-manufacturer) is studied with quadratic costs functional. It is assumed that both firms minimize the relevant costs. The order of the manufacturer is delayed with a known constant. Two cases are examined: supplier and manufacturer minimize the relevant costs decentralized, and a centralized decision rule. The question is answered, how to decrease the bullwhip effect.

A piaci likviditás hatása a vállalatokra (The effect of market liquidity for companies)

A 2007-ben kezdődő pénzügyi eredetű világgazdasági válság nyilvánvalóvá tette a kapcsolatot a likviditás két fajtája, a finanszírozási és a piaci likviditás között. A cikk megismertet a piaci likviditással kapcsolatos olyan alapvető fogalmakkal, mint order flow, ajánlati könyv, piaci struktúrák, bemutatja a piaci likviditás dimenzióit, a likviditás néhány mutatószámát és a piaci likviditás stilizált tényeit. A banki likviditáskezelés rövid összefoglalásán túl bevezetést nyújt a portfóliók likviditáskockázat melletti értékelésébe, végezetül összefoglalja, hogy az alapvetően finanszírozási likviditási kockázatnak kitett nem pénzügyi vállalatok hogyan vehetik figyelembe döntéseik meghozatalakor a piaci likviditást. _____________________ The global financial crisis starting in 2007 has showed that the connection between market liquidity and funding liquidity is apparent. This paper introduces the basic notions regarding market liquidity such as order flow, order book, and market structures. The article also presents the various dimensions of market liquidity, several measures of liquidity and the stylized facts of market liquidity. Besides a short description of liquidity management of banks it briefly introduces portfolio valuation in the presence of liquidity risk. Finally, the paper gives insight to non-financial companies, fundamentally exposed to funding liquidity risk, on how to consider market liquidity in their decisions.

The effect of climate change on the population of sycamore lace bug (Corythuca ciliata, Say) based on a simulation model with phenological response

Climate change affects on insect populations in many ways: it can cause a shift in geographical spread, abundance, or diversity, it can change the location, the timing and the magnitude of outbreaks of pests and it can define the phenological or even the genetic properties of the species. Long-time investigations of special insect populations, simulation models and scenario studies give us very important information about the response of the insects far away and near to our century. Getting to know the potential responses of insect populations to climate change makes us possible to evaluate the adaptation of pest management alternatives as well as to formulate our future management policy. In this paper we apply two simple models, in order to introduce a complex case study for a Sycamore lace bug population. We test how the model works in case the whether conditions are very different from those in our days. Thus, besides we can understand the processes that happen in present, we can analyze the effects of a possible climate change, as well.

The effect of the reproductivity's velocity on the biodiversity of a theoretical ecosystem

Climate change has a great impact on the build and the work of natural ecosystems. Disappearance of some population or growth of the number in some species can be already caused by little change in temperature. A Theoretical Ecosystem Growth Model was investigated in order to examine the effects of various climate patterns on the ecological equilibrium. This paper examines the diversity of a theoretical ecosystem on the grounds of changing in temperature-climate patterns. Simulations were made from the simplest case to the more complex exercise to explain harder questions. Daily temperature values were calculated according to various functions. The effect of existing climate patterns (historical or future daily temperatures) was analysed where temperature values were from various climatic zones. In this paper it is examined what kind of environmental conditions result larger diversity related to the velocity of reproduction.

Effect of sampling effort and sampling frequency on the composition of the planktonic crustacean assemblage: a case study of the river Danube

Although numerous studies have focused on the seasonal dynamics of riverine zooplankton, little is known about its short-term variation. In order to examine the effects of sampling frequency and sampling effort, microcrustacean samples were collected at daily intervals between 13 June and 21 July of 2007 in a parapotamal side arm of the river Danube, Hungary. Samples were also taken at biweekly intervals from November 2006 to May 2008. After presenting the community dynamics, the effect of sampling effort was evaluated with two different methods; the minimal sample size was also estimated. We introduced a single index (potential dynamic information loss; to determine the potential loss of information when sampling frequency is reduced. The formula was calculated for the total abundance, densities of the dominant taxa, adult/larva ratios of copepods and for two different diversity measures. Results suggest that abundances may experience notable fluctuations even within 1 week, as do diversities and adult/larva ratios.

The effect of a reform on a school organizational culture after receiving a failing Florida Comprehensive Assessment Test rating

The purpose of this research was to explore the effects of a reform that took place in an elementary school during 2000/2001 as a result of a failure rating on the Florida Comprehensive Assessment Test on the structure and the personnel of the organization. ^ The exploration took place over a period of 10 months starting in August 2000 until June 2001. It focused on the effect of the failure rating on the: (a) structure and operation of the school; (b) morale, beliefs, behaviors, and daily lives of teachers and the principal; and (c) the effect of the reform effort on the leadership style of the principal, whether she became a transactional or a transformative leader. ^ The researcher assumed the role of a participant observer. Data sources were her personal recollections of major events that took place during the year of the reform, interviews, observations, and school documents. The sample included 15 teachers present during the time of the reform. Ten taught second through fifth grade. The remaining five participants were the music teacher, the counselor, and the writing, reading and technology specialists. Together they represented the instructional team or represented special education areas. ^ The findings indicated that the reform effort had an effect on the structure and the operation of the school. The changes included reorganization of the physical set up, changes in curriculum and instruction, changes in the means of communication among the staff, and the addition of new staff members including an official agent of change. The reform had a greater effect on the daily lives of teachers and their morale than on their beliefs and behaviors. Teachers reported that during the effort their daily lives were stressful and their morale very low due to the enormous expectations that they had to meet. On the other hand, the reform effort had a positive effect on the daily life, morale, beliefs, and behaviors of the principal. It energized her. She spoke positively about the change. She functioned as an effective, positive, resilient transactional leader who did what was necessary in order to enable the teachers to cope with the complex situation. ^

Content -area teachers' perceptions of the effect of the meta -training on their instructional practices

The purpose of this study was to explore the content-area teachers' perceptions of the effect that compliance with the teacher training for content-area teachers of Limited English Proficient (LEP) students mandated by the Consent Decree had on their instructional practices within the content-area classroom. In order to provide an overview of the factors which had an effect on the content-area teachers' mandated training, various areas were reviewed: history of legislative actions that led up to the Consent Decree; stipulations set forth in the Consent Decree; Miami-Dade County Public Schools District LEP Plan including stipulations for teacher training; research on teacher training for teachers of language minority students; and the process of change. This descriptive study specifically addresses teachers' perceptions of the effectiveness of the mandated teacher training as it relates to language minority students. ^ Content-area teachers who had completed the mandated teacher training were surveyed using self-administered anonymous questionnaires mailed to their school sites. Questions focused on the teachers' perceptions of: students' need of second language instructional strategies within the content-area classroom; teacher training requirements mandated by the Consent Decree; and changes in their instructional practices as a result of the training. ^ Based on the responses of the subjects, the results of this study indicate the overall success of the training implemented to comply with the stipulations set forth in the Consent Decree. In general, the results indicate that the teachers perceive that they are ultimately in agreement with the mandated training. The results also indicate that the teachers perceive a need for second language strategies when working with language minority students. These results can serve as starting point for further research not only into teachers' perceptions of the effectiveness of training for teachers of language minority students but also into the outcomes of this teacher training as it is reflected within the classroom. ^

The effect of male -male competition and its underlying regulatory mechanisms on the electric signal of the gymnotiform fish Brachyhypopomus gauderio

Sexually-selected communication signals can be used by competing males to settle contests without incurring the costs of fighting. The ability to dynamically regulate the signal in a context-dependent manner can further minimize the costs of male aggressive interactions. Such is the case in the gymnotiform fish Brachyhypopomus gauderio, which, by coupling its electric organ discharge (EOD) waveform to endocrine systems with circadian, seasonal, and behavioral drivers, can regulate its signal to derive the greatest reproductive benefit. My dissertation research examined the functional role of the EOD plasticity observed in male B. gauderio and the physiological mechanisms that regulate the enhanced male EOD. To evaluate whether social competition drives the EOD changes observed during male-male interactions, I manipulated the number of males in breeding groups to create conditions that exemplified low and high competition and measured their EOD and steroid hormone levels. My results showed that social competition drives the enhancement of the EOD amplitude of male B. gauderio. In addition, changes in the EOD of males due to changes in their social environment were paralleled by changes in the levels of androgens and cortisol. I also examined the relationship between body size asymmetry, EOD waveform parameters, and aggressive physical behaviors during male-male interactions in B. gauderio, in order to understand more fully the role of EOD waveforms as reliable signals. While body size was the best determinant of dominance in male B. gauderio, EOD amplitude reliably predicted body condition, a composite of length and weight, for fish in good body condition. To further characterize the mechanisms underlying the relationship between male-male interactions and EOD plasticity, I identified the expression of the serotonin receptor 1A, a key player in the regulation of aggressive behavior, in the brains of B. gauderio. I also identified putative regulatory regions in this receptor in B. gauderio and other teleost fish, highlighting the presence of additional plasticity. In conclusion, male-male competition seems to be a strong selective driver in the evolution of the male EOD plasticity in B. gauderio via the regulatory control of steroid hormones and the serotonergic system.

Understanding the Effect of Protein Tyrosine Phosphatase Receptor Type 0 on Mammalian Sensory Development: Behavioral Studies on PTPRO Knockout Mice

Nerve development, which includes axon outgrowth and guidance, is regulated by many protein families, including receptor protein tyrosine phosphatases (RPTP's).Protein tyrosine phosphatase receptor type 0 (PTPRO) is a type III RPTP that is important for axon growth and guidance, as observed in chicks and flies. In order to examine the effects ofPTPRO on mammalian development, standard behavioral tests were used to compare mice lacking the gene for PTPRO (ROKO mice) to wild-type (WT) mice. The ROKO mice showed a significant delay in reacting to a thermal noxious stimulus, hotplate analgesia, when compared to the WT mice suggesting deficient nociceptive function. In a rotarod test for proprioceptive function the ROKO mice exhibited a significant decrease in the amount of time spent on the rotating rod than did the WT mice. Additional proprioception tests were performed including the climb, step reflex, beam, and mesh walk tests. In the climb and step (place) test, the ROKO group had a significantly lower accuracy in performing the tests than did the WT mice. Thus, mice lacking the PTPRO gene showed behavioral deficiencies that reflect impairment in sensory function, specifically for nociception and proprioception.

Dissolved Black Carbon in Grassland Streams: Is There an Effect of Recent Fire History?

While the existence of black carbon as part of dissolved organic matter (DOM) has been confirmed, quantitative determinations of dissolved black carbon (DBC) in freshwater ecosystem and information on factors controlling its concentration are scarce. In this study, stream surface water samples from a series of watersheds subject to different burn frequencies in Konza Prairie (Kansas, USA) were collected in order to determine if recent fire history has a noticeable effect on DBC concentration. The DBC levels detected ranged from 0.04 to 0.11 mg L−1, accounting for ca. 3.32 ± 0.51% of dissolved organic carbon (DOC). No correlation was found between DBC concentration and neither fire frequency nor time since last burn. We suggest that limited DBC flux is related to high burning efficiency, possibly greater export during periods of high discharge and/or the continuous export of DBC over long time scales. A linear correlation between DOC and DBC concentrations was observed, suggesting the export mechanisms determining DOC and DBC concentrations are likely coupled. The potential influence of fire history was less than the influence of other factors controlling the DOC and DBC dynamics in this ecosystem. Assuming similar conditions and processes apply in grasslands elsewhere, extrapolation to a global scale would suggest a global grasslands flux of DBC on the order of 0.14 Mt carbon year−1.

The Effect of Sample and Sample Matrix on DNA Processing: Mechanisms for the Detection and Management of Inhibition in Forensic Samples

The presence of inhibitory substances in biological forensic samples has, and continues to affect the quality of the data generated following DNA typing processes. Although the chemistries used during the procedures have been enhanced to mitigate the effects of these deleterious compounds, some challenges remain. Inhibitors can be components of the samples, the substrate where samples were deposited or chemical(s) associated to the DNA purification step. Therefore, a thorough understanding of the extraction processes and their ability to handle the various types of inhibitory substances can help define the best analytical processing for any given sample. A series of experiments were conducted to establish the inhibition tolerance of quantification and amplification kits using common inhibitory substances in order to determine if current laboratory practices are optimal for identifying potential problems associated with inhibition. DART mass spectrometry was used to determine the amount of inhibitor carryover after sample purification, its correlation to the initial inhibitor input in the sample and the overall effect in the results. Finally, a novel alternative at gathering investigative leads from samples that would otherwise be ineffective for DNA typing due to the large amounts of inhibitory substances and/or environmental degradation was tested. This included generating data associated with microbial peak signatures to identify locations of clandestine human graves. Results demonstrate that the current methods for assessing inhibition are not necessarily accurate, as samples that appear inhibited in the quantification process can yield full DNA profiles, while those that do not indicate inhibition may suffer from lowered amplification efficiency or PCR artifacts. The extraction methods tested were able to remove >90% of the inhibitors from all samples with the exception of phenol, which was present in variable amounts whenever the organic extraction approach was utilized. Although the results attained suggested that most inhibitors produce minimal effect on downstream applications, analysts should practice caution when selecting the best extraction method for particular samples, as casework DNA samples are often present in small quantities and can contain an overwhelming amount of inhibitory substances.

The Effect of male-male competition and its Underlying Regulatory Mechanisms on the Electric Signal of the Gymnotiform fish Brachyhypopomus gauderio

Sexually-selected communication signals can be used by competing males to settle contests without incurring the costs of fighting. The ability to dynamically regulate the signal in a context-dependent manner can further minimize the costs of male aggressive interactions. Such is the case in the gymnotiform fish Brachyhypopomus gauderio, which, by coupling its electric organ discharge (EOD) waveform to endocrine systems with circadian, seasonal, and behavioral drivers, can regulate its signal to derive the greatest reproductive benefit. My dissertation research examined the functional role of the EOD plasticity observed in male B. gauderio and the physiological mechanisms that regulate the enhanced male EOD. To evaluate whether social competition drives the EOD changes observed during male-male interactions, I manipulated the number of males in breeding groups to create conditions that exemplified low and high competition and measured their EOD and steroid hormone levels. My results showed that social competition drives the enhancement of the EOD amplitude of male B. gauderio. In addition, changes in the EOD of males due to changes in their social environment were paralleled by changes in the levels of androgens and cortisol. I also examined the relationship between body size asymmetry, EOD waveform parameters, and aggressive physical behaviors during male-male interactions in B. gauderio, in order to understand more fully the role of EOD waveforms as reliable signals. While body size was the best determinant of dominance in male B. gauderio, EOD amplitude reliably predicted body condition, a composite of length and weight, for fish in good body condition. To further characterize the mechanisms underlying the relationship between male-male interactions and EOD plasticity, I identified the expression of the serotonin receptor 1A, a key player in the regulation of aggressive behavior, in the brains of B. gauderio. I also identified putative regulatory regions in this receptor in B. gauderio and other teleost fish, highlighting the presence of additional plasticity. In conclusion, male-male competition seems to be a strong selective driver in the evolution of the male EOD plasticity in B. gauderio via the regulatory control of steroid hormones and the serotonergic system.

Modeling the Effect of Land Use and Climate Change Scenarios on the Water Flux of the Upper Mara River Flow, Kenya

Increasingly erratic flow in the upper reaches of the Mara River, has directed attention to land use change as the major cause of this problem. The semi-distributed hydrological model SWAT and Landsat imagery were utilized in order to 1) map existing land use practices, 2) determine the impacts of land use change on water flux; and 3) determine the impacts of climate change scenarios on the water flux of the upper Mara River. This study found that land use change scenarios resulted in more erratic discharge while climate change scenarios had a more predictable impact on the discharge and water balance components. The model results showed the flow was more sensitive to the rainfall changes than land use changes but land use changes reduce dry season flows which is a major problem in the basin. Deforestation increased the peak flows which translated to increased sediment loading in the Mara River.

The effect of a reform on a school organizational culture after receiving a failing Florida Comprehensive Assessment Test rating

The purpose of this research was to explore the effects of a reform that took place in an elementary school during 2000/2001 as a result of a failure rating on the Florida Comprehensive Assessment Test on the structure and the personnel of the organization. The exploration took place over a period of 10 months starting in August 2000 until June 2001. It focused on the effect of the failure rating on the: (a) structure and operation of the school; (b) morale, beliefs, behaviors, and daily lives of teachers and the principal; and (c) the effect of the reform effort on the leadership style of the principal, whether she became a transactional or a transformative leader. The researcher assumed the role of a participant observer. Data sources were her personal recollections of major events that took place during the year of the reform, interviews, observations, and school documents. The sample included 15 teachers present during the time of the reform. Ten taught second through fifth grade. The remaining five participants were the music teacher, the counselor, and the writing, reading and technology specialists. Together they represented the instructional team or represented special education areas. The findings indicated that the reform effort had an effect on the structure and the operation of the school. The changes included reorganization of the physical set up, changes in curriculum and instruction, changes in the means of communication among the staff, and the addition of new staff members including an official agent of change. The reform had a greater effect on the daily lives of teachers and their morale than on their beliefs and behaviors. Teachers reported that during the effort their daily lives were stressful and their morale very low due to the enormous expectations that they had to meet. On the other hand, the reform effort had a positive effect on the daily life, morale, beliefs, and behaviors of the principal. It energized her. She spoke positively about the change. She functioned as an effective, positive, resilient transactional leader who did what was necessary in order to enable the teachers to cope with the complex situation.