Information Acquisition and Investment Decisions on the Internet: An Empirical Investigation

With intensifying competition, the significance of understanding customer characteristics related to information acquisition and decision making on the Internet has increased. An understanding of customer characteristics can become a crucial element in the development and implementation of marketing strategy. This paper examines the influence of some key demographic and psychological variables on information acquisition and investment decisions on the Internet, related to mutual funds. Findings indicate that product familiarity, age, and information breadth significantly influenced information acquisition. For investment decisions on the Internet, in addition to the above-mentioned variables, sex and overconfidence was also significant

Signal processing with Fourier analysis, novel algorithms and applications

Fourier analysis is the study of the way general functions may be represented or approximated by sums of simpler trigonometric functions, also analogously known as sinusoidal modeling. The original idea of Fourier had a profound impact on mathematical analysis, physics and engineering because it diagonalizes time-invariant convolution operators. In the past signal processing was a topic that stayed almost exclusively in electrical engineering, where only the experts could cancel noise, compress and reconstruct signals. Nowadays it is almost ubiquitous, as everyone now deals with modern digital signals. Medical imaging, wireless communications and power systems of the future will experience more data processing conditions and wider range of applications requirements than the systems of today. Such systems will require more powerful, efficient and flexible signal processing algorithms that are well designed to handle such needs. No matter how advanced our hardware technology becomes we will still need intelligent and efficient algorithms to address the growing demands in signal processing. In this thesis, we investigate novel techniques to solve a suite of four fundamental problems in signal processing that have a wide range of applications. The relevant equations, literature of signal processing applications, analysis and final numerical algorithms/methods to solve them using Fourier analysis are discussed for different applications in the electrical engineering/computer science. The first four chapters cover the following topics of central importance in the field of signal processing: • Fast Phasor Estimation using Adaptive Signal Processing (Chapter 2) • Frequency Estimation from Nonuniform Samples (Chapter 3) • 2D Polar and 3D Spherical Polar Nonuniform Discrete Fourier Transform (Chapter 4) • Robust 3D registration using Spherical Polar Discrete Fourier Transform and Spherical Harmonics (Chapter 5) Even though each of these four methods discussed may seem completely disparate, the underlying motivation for more efficient processing by exploiting the Fourier domain signal structure remains the same. The main contribution of this thesis is the innovation in the analysis, synthesis, discretization of certain well known problems like phasor estimation, frequency estimation, computations of a particular non-uniform Fourier transform and signal registration on the transformed domain. We conduct propositions and evaluations of certain applications relevant algorithms such as, frequency estimation algorithm using non-uniform sampling, polar and spherical polar Fourier transform. The techniques proposed are also useful in the field of computer vision and medical imaging. From a practical perspective, the proposed algorithms are shown to improve the existing solutions in the respective fields where they are applied/evaluated. The formulation and final proposition is shown to have a variety of benefits. Future work with potentials in medical imaging, directional wavelets, volume rendering, video/3D object classifications, high dimensional registration are also discussed in the final chapter. Finally, in the spirit of reproducible research we release the implementation of these algorithms to the public using Github

(m,n)-Semirings and a Generalized Fault Tolerance Algebra of Systems

We propose a new class of mathematical structures called (m,n)-semirings} (which generalize the usual semirings), and describe their basic properties. We also define partial ordering, and generalize the concepts of congruence, homomorphism, ideals, etc., for (m,n)-semirings. Following earlier work by Rao, we consider a system as made up of several components whose failures may cause it to fail, and represent the set of systems algebraically as an (m,n)-semiring. Based on the characteristics of these components we present a formalism to compare the fault tolerance behaviour of two systems using our framework of a partially ordered (m,n)-semiring.Comment: 26 pages; extension of arXiv:0907.3194v1 [math.GM

Carbon stocks, greenhouse gas emissions and water balance of Sudanese savannah woodlands in relation to climate change

Understanding the carbon (C) sequestration potential of drylands requires knowledge of the stocks of C in soils and biomass and on the factors affecting them. The overall aim of the study was to determine and evaluate the variation in the C stocks and water balance of Acacia savannah woodlands across the dryland (arid and semi-arid) region (10-16 ºN; 21-36 °E) of the former Sudan (now mainly in the Republic of the Sudan) and how they are related to climatic factors and may be affected by climate change. The role played by small but numerous brick making industries on woodland deforestation in the region and greenhouse gas production was also investigated. The study region is often referred to as the gum belt because it is the world s major source of gum Arabic, which is harvested from Acacia trees. The soils in the centre and west of the region are mainly Arenosols (sandy soils) and those in the eastern part are mainly Vertisols (clay soils). The soils are C poor and often in a degraded state. This dissertation consists of a summary section and four articles (Study I, II, III and IV). Study I focuses on fuelwood consumption by the brick making industries (BMIs) and associated deforestation and greenhouse gas (GHG) emissions. In Study II the C densities (g C m-2) of the woodland tree biomass and soil (1 m) for 39 map sheets covering the study region were determined from national forest inventory data and global soil databases and the dependence on mean annual precipitation (MAP) and mean annual temperature (MAT) determined. The water balance of savannah woodlands for the same 39 map sheets was modelled in Study III and the variation in water balance components across the region evaluated. The potential impacts of climate change on woodland biomass C density and water-use (actual evapotranspiration, AET) was analysed for eight of the map sheets in Study IV. Sudanese BMIs consume a considerable amount of fuelwood that mainly comes from unsustainably managed woodland and contributes to deforestation and GHG emissions (Study I). While GHG emissions from BMIs only account for a small part of Sudan s total GHG emissions, the associated deforestation and land degradation is of concern. Implementation of better regulation, use of biomass fuel from sustainable sources and technological improvement in BMIs kilns will reduce deforestation and GHG emissions. Savannah woodland C densities, both biomass and soil, were low and clearly below potential C sequestration capacity (Study II). The loss of trees across the region was indicated by very low biomass C density values in comparison to modelled NPP (net primary production) values. The estimated SOC densities although low, were higher than reported in some recent soil C studies from the region. This was attributed to the use of old data in the global soil database and indicates the degree of land degradation and loss of SOC that has taken place over the last few decades. However, in spite of woodland and soil degradation, biomass C and SOC densities remained positively and significantly correlated with each other and both were significantly correlated to MAP. The results highlighted the need for improved land-use management and stewardship, which should involve increasing the cover of trees, and the need for up-to-date regional and integrated soils and forest (woodland) inventories to be made. Water-use (AET) of savannah woodlands is strongly limited by rainfall. Rainfall exceeded AET only during some of the wet season months resulting in a small increase in soil moisture storage and production of surface runoff for some areas (Study III). Drainage (to groundwater) was negligible. Since AET was strongly limited by MAP, AET for both Arenosol and Vertisol soil types increased southwards across the study region. Runoff also increased southwards across the study region for both soil types but were highest in south western and eastern areas. The restoration of woodlands may be expected to improve the soil-water conditions. Compared to baseline (1961-1990) climate values, General Circulation Model (GCM) based results for 2080s indicated that MAT would increase across the study region but that MAP would either increase or decrease depending on climate change scenario (Study IV). Biomass C densities will be significantly affected by climate change. However, the impact varies with climate change scenario, with either increases or decreases in biomass C density being indicated for the same area. In general, water-use on Arenosols will increase while that on Vertisols will decrease. The largest relative changes in AET were associated with the areas receiving the lowest rainfall. Thus, even if MAP increases, the increase will have little impact on biomass levels in the driest areas of the region.Työssä tarkasteltiin tropiikin kuivien alueiden hiilensidontakykyä ja siihen vaikuttavia tekijöitä. Tarkastelussa keskityttiin Sudanin savannialueen (10-16 ºN; 21-36 °E) hiilivarastojen ja vesitaseen vaihteluihin ja siihen kuinka ne riippuvat alueen ilmastollisista tekijöistä ja ennustetusta ilmastonmuutoksesta. Työssä selvitettiin myös, kuinka laajalti harjoitettu pienen mittakaavan tiilenpoltto vaikuttaa kuivuusalueen puustonkatoon ja hiilipäästöihin. Alue tunnetaan yleisesti esiintyvistä akaasiapuista ja niistä saatavasta arabikumista, jonka pääasiallinen lähde kyseinen Afrikan ilmastovyöhyke (gum belt) on maailmassa. Työ koostuu neljästä osatutkimuksesta ja niiden yhteenvedosta. Ensimmäisessä osajulkaisussa selvitettiin tiiliteollisuuden polttopuun käyttöä ja siihen liittyvää puustonkatoa ja kasvihuonekaasujen (KHK) päästöjä. Toisessa osajulkaisussa arvioitiin julkaistujen valtakunnan metsien inventointitietojen ja maailman maaperätietokannan perusteella savannialueiden puuston ja pintamaan (1 m syvyyteen asti) hiilimääriä ja niiden korreloitumista vuotuisen keskimääräisen sadannan ja lämpötilan kanssa. Kolmannessa osajulkaisussa mallinnettiin alueen vesitaseen ja sen eri tekijöiden vaihtelua ja neljännessä osatyössä analysoitiin eri ilmastonmuutosskenaarioiden vaikutusta kasvillisuuteen sitoutuvaan hiilimäärään ja kasvillisuuden veden käyttöön. Osatyöt II ja III tehtiin 39 karttapohjalle, jotka kattoivat koko alueen, mutta osatyössä IV käytettiin vain kahdeksan karttapohjan osajoukkoa. Pääosa Sudanin tiilitehtaiden polttopuusta poimitaan hoitamattomista luonnonpuustoista. Vaikka tiiliteollisuuden hiilipäästöt ovat pieniä suhteessa koko maan hiilipäästöihin, kestämätön puunkäyttö aiheuttaa puustonkatoa ja maaperän köyhtymistä. Nykyhetkellä savannialueen hiilimäärät ovat paljon potentiaalista kapasiteettia alhaisempia. Maailman maaperätietokannan suhteellisen vanhojen tietojen perusteella lasketut maan hiilimäärät osoittautuivat suuremmiksi kuin mitä alueella hiljattain tehdyt tutkimukset antoivat. Tämä osoittaa maan köyhtymistä ja orgaanisen hiilen määrän vähenemistä maaperästä. Kuitenkin sekä puuston että maaperän hiilimäärät korreloivat merkitsevästi sekä keskenään, että keskimääräisen sadannan kanssa. Alueen kasvillisuuden vedenkäyttöä rajoittaa sadannan vähyys. Vain joinakin sadekauden kuukausina vettä kertyi maan vesivarastoihin ja siirtyi pintavaluntana vesistöihin, lisääntyen kuitenkin etelää kohti mentäessä yhdessä sadannan kanssa. Ilmastomallien perusteella vuotuinen keskilämpötila nousee koko alueella referenssitasoon (1961-1990) verrattuna, mutta keskimääräinen sadanta joko nousee tai laskee riippuen käytetystä skenaarioarviosta. Tällä tulee olemaan selkeä joko lisäävä tai vähentävä vaikutus ekosysteemeihin sitoutuneeseen hiileen. Suurimmat vaikutukset on odotettavissa jo nykyään kuivimmilla alueilla. Tutkimus osoitti selvästi, että alueen ekosysteemeihin sitoutunut hiili on vähentynyt ja sillä on negatiivinen vaikutus maaperän vesitaseeseen. Ilmastonmuutoksen myötä kyseiset ongelmat saattavat edelleen kärjistyä. Polttopuun käyttöä järkeistämällä ja kestävällä puustonhoidolla voidaan kyseistä ongelmaa pienentää ja varautua ilmastonmuutoksen vaikutuksiin

Mapping Mutual Fund Investor Characteristics and Modeling Switching Behavior

Securing a mutual fund that meets investment goals is an important reason why some investors exclusively stay with a particular mutual fund and others switch funds within their fund family. This paper empirically investigates investor attitudes toward mutual funds. Our model, based on investor responses, develops an investor\u27s risk profile variable. Results indicate that regardless of whether the investors invest in nonemployer plans or in both employer and nonemployer plans, they consider their investment risk, fund performance, investment mix, and the capital base of the fund before switching funds. The model developed in this study can also assist in predicting investors\u27 switching behavior

Energy and spectral efficiency tradeoff in wireless communication

In the wireless communication world, a significant number of new user equipments is connecting to the network each and every day, and day after day this amount is increasing with no known bounds. Diverse quality of service (QoS) along with better system throughput are the crying needs at present. With the advancement in the field of massive multiple-input multiple-output (MMIMO) and Internet-of-things (IoT), the QoS is provided smoothly with the limited spectrum by the wireless operator. Hundreds of antenna elements in the digital arrays are set up at the base station in order to provide the smooth coverage and the best throughput within these spectra. However, implementing hundreds of antenna elements with associated a huge number of RF chains for digital beamforming consumes too much energy. Energy efficiency optimization has become a requirement at the present stage of wireless infrastructure. Due to the conflicting nature between the energy efficiency and the spectral efficiency, it is hard to make a balance. This thesis investigates how to achieve a good tradeoff between the energy and the spectral efficiency with maximum throughput outcomes from MMIMO, with the help of existing topologies and a futuristic perspective. Although the signal noise power is less in massive MIMO than the conventional cellular system, it still needs to be decreased and at the same time, the average channel gain per user equipment must be increased. Fixed power requirement for control signaling and load-independent power of backhaul infrastructure must be cut at least by a factor two as well as the power amplifier efficiency has to increase by 10% than LTE networks. The minimum mean square error (MMSE) estimator can be a possible solution in terms of the energy and the spectral efficiency despite having computational complexity which can be solved with the aid of Moore’s law and it is proposed by the non-profit research organization IMEC, which has developed an online web tool for observing and predicting contemporary as well as futuristic cellular base station’s power consumption. It supports various types of base stations with a wide range of operating conditions. The multicell minimum mean square error (M-MMSE) scheme can perform better than other existing schemes and showcase satisfactory tradeoff with frequency reuse factor higher than 2, where regularized zero-forcing (RZF) and maximum ratio (MR) combining fall down their capabilities for performing. With the precipitous rising of IoT, the Narrowband Internet-of-things (NB-IoT) may play an efficient supportive role if we can collaborate it with MMIMO. With its low power, wide area topologies combining with MMIMO technologies can show better tradeoffs. Due to its narrow bandwidth, the signal noise power would be less compared to the existent wideband topologies, and the average channel gain of active user equipment would be higher too. Hence it will give a great impact in terms of the tradeoff between energy and the spectral efficiency which is addressed in this thesis

Othering: An Analysis of Expression in Hip-Hop and South Asian Literature Through Post-9/11 Discourse

The critical question this thesis seeks to answer is how a relationship between hip-hop and South Asian literature can be developed in such a way that one is able understand and address both the present and future state of America in a post 9/11 context. To answer this question, three hip-hop songs will be analyzed through their lyrics and instrumentation with a specific focus on their expression of the other: “Cops Shot the Kid” by Nas, “Flag Shopping” and “Patriot Act” by Heems. One novel and play will be analyzed in similar form: The Reluctant Fundamentalist by Mohsin Hamid and Disgraced by Ayad Akhtar. Following the hip-hop and literature sections will be a comparative analysis of each medium’s expression of the other within a post 9/11 context. As for a provisional argument, I believe that it would be accurate to conclude that, through a comparative analysis of these two mediums, an America moving forward develops a blur in the identities of South Asian Americans. By this, I mean that the forced assimilation they endure as a result of systemic racism has produced an effect on South Asian Americans that puts them at odds with what culture they most identify with, which ultimately reduces their own culture to a choice that they have to make

Modified YSK12-MEND-siRNA in Dendritic Cells for Cancer Immunotherapy

Tumors may induce tolerogenesis through signaling dendritic cells to produce tolerogenic molecules, such as indoleamine 2, 3-dioxygenase 1 (IDO1). Tumor-associated immunosuppression is associated with higher mortality in patients. Small interfering RNA (siRNA) has been shown to silence specific target genes in the target cell. The siRNA associated with these genes could support a gene knockdown of these immunosuppressors and reduce mortality. Delivery of these therapeutic nucleic acids is difficult in vivo because siRNA is easily broken down inside the cell and the bloodstream through present nucleases. Use of liposome polymers has been reviewed extensively in literature. YSK12-C4, a lipid nanoparticle developed by Hokkaido University, is a lipid that has both fusogenic and cationic properties, making it ideal for dendritic cell uptake. However, limitations make it less effective in vivo as it may collect in areas other than the target human dendritic cells in the draining lymph node. To improve specific targeting in vivo, ligand-based targeting modifications (anti-DEC205, anti-CD11c, mannose+) and physical targeting (pKa modifications through YSK05 lipid addition) have been proposed to the YSK12-MEND system in order to better target dendritic cells in vivo. In order to estimate the theoretical efficacy of modified YSK12-MEND-siRNA, I investigated prior experiments, both in vivo and in vitro, to recognize the practicality of each modification. In murine hepatocytes, it was found that pKa improved specific uptake in vivo while anti-DEC205 and anti-CD11c peptides were found to be effective in dendritic cells in vivo in mice. Mannose+ lipid nanoparticles were ideal for targeting both dendritic cells and macrophages. These modifications will likely result in an improved uptake, more cell specificity, and transfection efficiency for human dendritic cells.https://scholarscompass.vcu.edu/uresposters/1423/thumbnail.jp