Data Mining in Electronic Commerce

Modern business is rushing toward e-commerce. If the transition is done properly, it enables better management, new services, lower transaction costs and better customer relations. Success depends on skilled information technologists, among whom are statisticians. This paper focuses on some of the contributions that statisticians are making to help change the business world, especially through the development and application of data mining methods. This is a very large area, and the topics we cover are chosen to avoid overlap with other papers in this special issue, as well as to respect the limitations of our expertise. Inevitably, electronic commerce has raised and is raising fresh research problems in a very wide range of statistical areas, and we try to emphasize those challenges.Comment: Published at http://dx.doi.org/10.1214/088342306000000204 in the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Lateral vibration of pedestrian bridges

Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2001."June 2001."Includes bibliographical references (leaf 56).by Yasmin H. Rehmanjee.M.Eng

Positive susceptibility vessel sign on SWI-MRI sequence imaging might differentiate patients had silent brain ischemia among apparently neurologically-free patients

Background: The susceptibility-weighted imaging (SWI) is an essential MRI sequence in the assessment of acute ischemic stroke. Silent cerebrovascular disease is five times more prevalent than symptomatic brain infarcts and is associated with future risk for stroke and dementia.Objectives: Evaluation of the diagnostic performance of susceptibility-weighted magnetic resonance sequence imaging (SWI) for early diagnosis of silent brain infarction (SBI) in apparently neurologically-free patients presented by transient neurological manifestations.Patients and Methods: The study included 218 patients who were clinically evaluated for demographic, clinical data concerning presence of chronic medical diseases, presenting symptoms and its frequency and severity. Routine lab investigations and lipid profile were performed and the plasma atherogenic index (PAI) for oncoming cardiovascular insults was calculated. MRI scan was performed using 1.5 T MRI scanner (Toshiba Vantage) with a head coil. Results: 102 patients (46.8%) had chronic medical diseases and hypertension (HTN) and diabetes mellitus (DM) are the most common. The commonest complaint was occasional amnesia, slurred speech and weak handgrip. PAI defined 53 patients at high, 101 patients at intermediate and 64 patients at low risk of cardiovascular insults. Susceptibility vein sign (SVS)+ were detected in 78 SWI scans and showed positive significant correlation with smoking, multiple co-morbidities, presence of chronic kidney disease, DM, hypertension and with PAI.Conclusion: The presence of SVS in SWI during MRI examination is pathognomonic sign for the presence of SBI. The incidence of SBI on SWI scans of apparently neurologically free patients who presented by transient neurological manifestations is high and was found to be associated with the presence of chronic medical diseases especially in obese dyslipidemic patients

Gestational Age and Pregnancy Outcomes

Some of the important pregnancy outcomes such as preterm delivery, growth restriction and low birth weight (LBW) infant, stillbirth, and some long-term chronic diseases vary by race and ethnicity but also tend to be associated with gestational age of the infant at birth. In the United States, during the last 25–30 years, the rate of low birth weight has increased, as has the rate of preterm delivery among both whites and blacks. Examination of causes for these secular trends has focused mainly on changes in the distribution of maternal age, race, and certain psychosocial factors. However, gestational age at birth is associated with most of these pregnancy outcomes, particularly infant mortality, certain morbidities, birth weight, and preterm birth. In this chapter, the association between gestational age and some significant pregnancy outcomes will be discussed

Trade Liberalisation and Labour Demand Elasticities: Empirical Evidence for Pakistan

Trade has predominantly contributed in the development of world economies for more than mere agricultural development and industrialisation. Trade involves many regions across the globe. The more the regions involved, the more will be the benefits. Trade is an interaction between economies for the exchange of goods, services, skills, knowledge and expertise, which is required for bringing in the desired changes like increase in the availability of choices, reduction of extreme poverty, and enhancement of physical and mental capability. As the wave of market oriented moves has spread over the economic sphere, global trend has also been witnessed in the liberalisation of capital account, foreign exchange, credit, domestic consumption and trading sector of many countries. The concept, which has been predominantly emphasised by the economies, is that of “trade liberalisation”, which has become the key element of any development policy since late 1970s after the fundamental change in the economic policy at global level. The concept of trade liberalisation stems from Neo-liberalism thinking that has advocated market oriented economic reforms for social order and economic prosperity that aims to improve efficiency and stability in the economy. Trade liberalisation process can be defined in many different ways. In the words of Krueger (1978), “any policy, which reduces the anti export bias will lead towards liberalisation of trade and reduction in import license premium is the fundamental step towards liberalised trade regime”

Assigning optimum time period for using evaporation cooling systems in Iraq

Increasing demand on electricity power during summer in Iraq because of increasing averages of temperature reached 47 ºC and continuous to increase and the problems facing Iraq is the increasing in peak load for the electrical system because of using cooling and air-conditioning operated by compressed gases, according it is obliged to search  for alternative methods to activate   electrical power consumption and one of solutions and processing is  using application of cooling  by evaporation (evaporation coolers) consumed less electrical and  power compared with other cooling devices  which provide power of amount (80%) and for what Iraq characterized by climate conditions such as  scarcity of relative humidity among the research results, the general average of monthly average of relative humidity in Iraq during the summer season (the study period) for 36 years for the period (1980-2015) not exceeded (42%) as for  the general average of the monthly average of temperature for the same period was higher average for it (31 ºC) and for these two elements are the core to identify the cooling  efficiency, according Iraq is considered one of the  good area to use the evaporation cooling applications, where the general average  of monthly average of cooling efficiency for the same period was higher average(51%) and the optimum time period  for using the evaporation  cooling applications in Iraq  in July at  Salahdd in  city center with monthly efficiency average (60%)

Lie algebra representations and 2-index 4-variable 1-parameter Hermite polynomials

This paper is an attempt to stress the usefulness of multi-variable special functions by expressing them in terms of the corresponding Lie algebra or Lie group. The problem of framing the 2-index 4-variable 1-parameter Hermite polynomials (2I4V1PHP) into the context of the irreducible representations $\uparrow _{\omega,\mu}$ of $\mathcal{G}(0,1)$ and $\uparrow^{'} _{\omega,\mu}$ of $\mathcal{K}_{5}$ is considered. Certain relations involving 2I4V1PHP $H_{m,n}(x,y,z,u;\rho)$ are obtained using the approach adopted by Miller. Certain examples involving other forms of Hermite polynomials are derived as special cases. Further, some properties of the 2I4V1PHP $H_{m,n}(x,y,z,u;\rho)$ are obtained by using a quadratic combination of four operators defined on a Lie algebra of endomorphisms of a vector space

Konsumententypologisierung im elektronischen Handel : eine interkulturelle Untersuchung

In dem Spannungsfeld zwischen wachsenden globalen Absatzmärkten und individueller Nutzenerwartungen erlangt das Prinzip der differenzierten Marktbearbeitung eine hervorragende Bedeutung. Nach Überzeugung zahlreicher Vertreter der Marketing-Praxis stellen in diesem Kontext globale Konsumententypologien ein wirkungsvolles Instrument dar, um der Herausforderung gerecht zu werden, trotz globaler Marktaktivitäten verschiedenartige Verbraucher-Cluster zu identifizieren und zu bearbeiten. Obgleich sich der internationale Wettbewerb im elektronischen Handel intensiviert, existieren nur wenige Typologien von Internet-Nutzern, welche zudem ein auffallend heterogenes Bild abgeben. Angesichts des Mangels an theoretisch fundierten Internet-Nutzertypologien ist es das Erkenntnisziel der vorliegenden Studie zu untersuchen, ob es sich bei den internationalen Online-Usern um eine homogene Zielgruppe handelt, oder ob sich mittels ausgewählter Typologisierungskriterien wie psychographischer, kulturspezifischer und kaufverhaltensrelevanter Merkmale trennscharfe, praxisrelevante und bearbeitbare Segmente identifizieren lassen, die es einem Online-Anbieter ermöglichen, seine Marketingaktivitäten effizient und effektiv auf die attraktiven Verbrauchersegmente auszurichten. Mittels einer Online-Befragung, an der 1011 Probanden aus drei Ländern teilnah-men, wurde nachgewiesen, dass sich die Internet-Nutzer hinsichtlich psychographischer, kaufverhaltensrelevanter und kultureller Prädispositionen trennscharf in drei Cluster, dem „Risikoscheuen Skeptiker“, dem „Aufgeschlossenen Online-Shopper“ und dem „Verhaltenen Informationssucher“, einteilen lassen, deren Charakteristika ausführlich beschreiben werden. Implikationen aus diesem Ergebnis werden im letzten Kapitel ausgeführt. Sie können der Marketing-Praxis Anhaltspunkte zur Identifikation, Selektion und bedürfnisgerechten Bearbeitung erfolgsträchtiger Online-Konsumentensegmente geben

Convective Heat Transfer Analysis on Prandtl Fluid Model with Peristalsis

The effects of magnetohydrodynamic (MHD) on peristaltic transport of Prandtl fluid in a symmetric channel have been studied under the assumptions of long wave length and low-Reynolds number. Channel walls are considered compliant in nature. Series solutions of axial velocity, stream function and temperature are given by using regular perturbation technique for small values of Prandtl fluid parameter. The effects of physical parameters on the velocity, streamlines and temperature are examined by plotting graphs

Detection of Cronobacter sakazakii (Enterobacter sakazakii) in powdered food infants (PIF) and raw milk in Iraq

This study was conducted to detect C.sakazakii PIF and raw milk. Two hundred samples of PIF were taken from the infected hospital infants who used this type of milk and from the local markets in addition to 16 sample of raw milk were collected. The study is the first to report the isolation of C. sakazakii and Enterobacter spp. from raw milk in Iraq. The distribution of C.sakazakii and Enterobacter spp. among the presumptive isolates using Vitek-GN2 system gave 1/16(6.25%) isolates of C.sakazakii and 4/16 (25%) isolates of Enterobacter spp. Enterobacter spp. isolates include (E.cloacae ssp. cloacae and E.cloacae ssp. dissolvens, E.hormaechei, and E.ludwigii) that isolate from raw milk Differences in between percentages of each isolate persence were non-significant (