• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 286
  • 138
  • 49
  • 34
  • 33
  • 31
  • 26
  • 10
  • 9
  • 6
  • 6
  • 6
  • 4
  • 4
  • 4
  • Tagged with
  • 746
  • 196
  • 95
  • 71
  • 64
  • 61
  • 58
  • 49
  • 49
  • 47
  • 46
  • 46
  • 45
  • 40
  • 40
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Numerical Methods for Long-Term Impulse Control Problems in Finance

Belanger, Amelie January 2008 (has links)
Several of the more complex optimization problems in finance can be characterized as impulse control problems. Impulse control problems can be written as quasi-variational inequalities, which are then solved to determine the optimal control strategy. Since most quasi-variational inequalities do not have analytical solutions, numerical methods are generally used in the solution process. In this thesis, the impulse control problem framework is applied to value two complex long-term option-type contracts. Both pricing problems considered are cast as impulse control problems and solved using an implicit approach based on either the penalty method or the operator splitting scheme. The first contract chosen is an exotic employee stock option referred to as an infinite reload option. This contract provides the owner with an infinite number of reload opportunities. Each time a reload occurs, the owner pays the strike price using pre-owned company shares and, in return, receives one share for each option exercised and a portion of a new reload option. Numerical methods based on the classic Black-Scholes equation are developed while taking into account contract features such as vesting periods. In addition, the value of an infinite reload option to it's owner is obtained by using a utility maximization approach. The second long-term contract considered is a variable annuity with a guaranteed minimum death benefit (GMDB) clause. Numerical methods are developed to determine the cost of the GMDB clause while including features such as partial withdrawals. The pricing model is then used to determine the fair insurance charge which minimizes the cost of the contract to the issuer. Due to the long maturity of variable annuities, non-constant market parameters expressed through the use of regime-switching are included in the GMDB pricing model.
82

Non-uniform Interstitial Loading in Cardiac Microstructure During Impulse Propagation

Roberts, Sarah F. January 2009 (has links)
<p>Impulse propagation in cardiac muscle is determined not only by the excitable properties of the myocyte membrane, but also by the gross and fine structure of cardiac muscle. Ionic diffusion pathways are defined by the muscle's interconnected myocytes and interweaving interstitial spaces. Resistive variations arising from spatial changes in tissue structure, including geometry, composition and electrical properties have a significant impact on the success or failure of impulse propagation. Although much as been learned about the impact of discrete resistive architecture of the intracellular space, the role of the interstitial space in the spread of electrical activity is less well understood or appreciated at the microscopic scale. </p><p>The interstitial space, or interstitium, occupies from 20-25% of the total heart volume. </p><p>The structural and material composition of the interstitial space is both complex and </p><p>heterogeneous, encompassing non-myocyte cell structures and a conglomeration of </p><p>extracellular matrix proteins. The spatial distribution of the interstitium can vary from confined spaces between abutting myocytes and tightly packed cardiac fibers to large gaps between cardiac bundles and sheets</p><p>This work presents a discrete multidomain formulation that describes the three-dimensional ionic diffusion pathways between connected myocytes within a variable interstitial physiology and morphology. Unlike classically used continuous and discontinuous models of impulse propagation, the intracellular and extracellular spaces are represented as spatially distinct volumes with dynamic and static boundary conditions that electrically couple neighboring spaces to form the electrically cooperative tissue model. The discrete multidomain model provides a flexible platform to simulate impulse propagation at the microscopic scale within a three-dimensional context. The three-dimensional description of the interstitial space that </p><p>encompasses a single cell improves the capability of the model to realistically investigate the impact of the discontinuous and electrotonic inhomogeneities of the myocardium's interstitium.</p><p>Under the discrete multidomain representation, a non-uniformly described interstitium </p><p>capturing the passive properties of the intravascular space or variable distribution and </p><p>composition of the extracellular space that encompasses a cardiac fiber creates an </p><p>electrotonic load perpendicular to the direction of the propagating wavefront. During </p><p>longitudinal propagation along a cardiac fiber, results demonstrate waveshape </p><p>alterations due to variations in loads experienced radially that would have been otherwise masked in traditional model descriptions. Findings present a mechanism for eliminating myocyte membrane participation in impulse propagation, as the result of decreased loading experienced radially from a non-uniformly resistive extracellular space. Ultimately, conduction velocity increases by decreasing the "effective" surface-to-volume ratio, as theoretically hypothesized to occur in the conducting Purkinje tissue.</p> / Dissertation
83

Laminated Gas Generator Actuator Arrays

English, Brian Alan 20 November 2006 (has links)
Existing microactuator limitations prevent control of small-scale, spin-stabilized vehicles. These applications require actuators insensitive to shock that have forces on the order of Newtons and millisecond control periods. This research presents batch-fabrication lamination approaches for the realization of large arrays of high-impulse, short-duration gas generator actuators (GGAs), and system implementation approaches to integrate these GGAs into a small-scale, spin-stabilized projectile for the purpose of generating steering forces on the projectile. Electronic packaging and MEMS processing are combined to batch-fabricate millimeter-scale GGAs insensitive to large shocks. Robust, prefabricated thermoplastic and metal films are patterned by laser machining or photolithography, and multilayer devices are assembled by adhesive lamination. The GGAs remained operational after 10,000 g shocks. Optimized design and propellant selection enables control of the force profile and actuation timing. Rapid force rise times are achieved using appropriately selected solid propellants and specially designed hot-wire igniters that create a larger combustion fronts. By reshaping the combustion profile of the solid propellant, tens of Newtons are generated within milliseconds. In addition to force control, the timing of the force application was controllable to within 1 ms for optimized GGAs. Performance results demonstrate that GGA actuator arrays actuate within appropriate timescales and with enough authority to control a 40 mm projectile with a spin rate of 60 Hz. After actuator characterization, GGAs, control electronics, and power supply are mounted into a 40 mm diameter projectile, and a full flight system was flown to demonstrate divert authority of the GGAs.
84

A Study of Sales Promotion Effects on Perceptive Value, Purchasing Intention and Loyalty- A Case of Watsons Drugstore.

Chu, Yung-Cheng 02 March 2010 (has links)
Financial Crisis has seriously shut down global economy and Taiwan also couldn¡¦t escape from the strike of current Financial Tsunami. Under this condition, consumers become stricter on budgeting. Especially as rising price causes real income decrease, consumers would pinch pennies on necessity spending. We all know Watsons is the famous chain store of cosmeceuticals, which sells not only medicine but also cosmetics and commodities. Thus, this research takes Watsons as the example to explore the relationship among sales promotion, perceptive value, purchasing intention, and customer¡¦s loyalty. The main purposes as follows. 1. To understand customer¡¦s view towards sale promotion campaigns of Watsons. 2. To explore whether different sales promotion campaigns influence perceptive value, purchasing intention or customer¡¦s loyalty. 3. To discuss the relationship among sales promotion, perceptive value, purchasing intention, and customer¡¦s loyalty. 4. To analyze whether impulse purchasing characteristics modifies the effect of sales promotion on perceptive value, purchasing intention, and customer¡¦s loyalty. According to SPSS statistic analysis software, I have some findings as follows¡G 1. Customers prefer ¡§pay one more dollar, get one more item¡¨ than ¡§Redeem¡¨ 2. Different sales promotion cause different influences on perceptive value, purchasing intention, and customer¡¦s loyalty. 3. The effect of sales promotion on purchasing intention and customer¡¦s loyalty is significant. 4. Impulse purchasing characteristic doesn¡¦t have modified effect.
85

Economic Policy Effect in Quterly-dependence VAR model: Empirical Analysis of Taiwanese cases

Liu, Chun-I 30 June 2010 (has links)
abtract This paper uses a seasonal dependence VAR model that is proposed by Olivei and Tenreyro in the year 2007.We are to assess whether the effect of a policy exogenous shock differs according to the quarter in which the shock occur. We consider Taiwan as a small open economy with flourishing international trade; the effect of exchange rate is viewed as an important transmission channel in monetary transmission mechanism. First part, we consider domestic monetary policy shock how to influence macroeconomic variables. Second part, the United State is powerful around the world. The Fed policies whether affect Taiwan macroeconomic or not. Finally, discuss an exogenous shock on the exchange rate to impact Taiwan macroeconomic.
86

The Analysis of Long-run Real Exchange Rate in Japan

Liu, Ya-chun 26 July 2010 (has links)
Purchasing Power Parity (PPP) has been regarded as the most important theory to explain the exchange rate movement based on relative price levels of two countries. After 1973, more and more countries were taking the floating exchange rate system, and the real exchange is testing out to be a non-stationary time seriess. This would be some real factors to have an effect on the real exchange rate. In the article, We study how these possible factors change the real exchange rate and make use of Wu et.al (2008) and Lee (2010)¡¦s local projection to estimate the impulse responses under the non-stationary time series which has cointegration vectors, and then we compare the difference between the impulse response in conventional VAR and the impulse response in Local Projection. The emprical model we use is the smae one as in Zhou (1995) and Wang and Dunne (2003), and the rule of the data is the same as in Wang and Dunne (2003). Finally, we get the consistent conclusion with Wu et.al (2008), Zhou (1995) and Wang and Dunne (2003).
87

The Impulse Response Analysis of General Inference on Cointegration Vector for Non-Stationary Process by Local Projection

Lin, Meng-wei 26 July 2010 (has links)
Jorda (2005) proposed the new method to estimate impulse response functions by local projection. The new method, local projection, can avoid the misspecification problem. That is, local projections are robust to misspecification of the data generating process (DGP). Wu, Lee, and Wang (2008) extended the Jorda¡¦s local projection from stationary time series I(0) to non-stationary time series I(1). It makes the local projection be a more generally applicative method for the Macroeconomic. In the article, I relax the cointegration vector which assumed to be known in the Wu, Lee, and Wang (2008) and Lee(2010). From the inference of Johansen (1995) I can get the property of super-consistent between £] and ˆ £] in the cointegration vector. I use the above condition and OLS to estimate impulse response functions, and in the asymptotic theorem, the cointegration vectors which assumed to be known or estimated by Johansen MLE are both get the consistent coefficients of impulse responses.
88

The Impact of The Monetary Polciy in Taiwan-A FAVAR Model Approach

Chu, I-Ching 19 July 2011 (has links)
This paper applies a Factor-Augmented VAR model proposed by Bernanke, Boivin and Eliasz (2005) to measure the impact of the monetary policy in Taiwan. Our empirical results show that, first, the more the factors added in the benchmark VAR, the more we can explain the price puzzle problem. Second, the effect of the tightening in the monetary policy (the increase in the interbank overnight lending rate) is inconsistent with the results expected by the credit channel.
89

The Research of Consumers Behavior in Kaohsiung Multimedia Exhibition Event

Chien, Kuo-Chung 03 August 2011 (has links)
Nowadays, most consumers prefer products with originality, fashion and innovation, and seek for quality and design. In addition, by the effects of the popularized knowledge of media products, the increasing educational level, the change of social concepts and the frequent interaction between human-beings, the demand of multimedia merchandises is raising and the expenditure is also increasing. The purpose of this study is to discuss the impact factors of purchase behavior by impulse buying and the relationship between the background knowledge to products and the purchase intention in multimedia expos in Kaohsiung area. After deleting invalid questionnaires, 501 of 550 research objects who were the consumers in the multimedia expo in Kaohsiung were taken into this study. The results which were made by research tools such as impulse buying scale, impulse buying behavior factors scale, product knowledge scale and purchase intention scale through statistic methods including reliability test, item analysis, factor analysis, descriptive statistics, independent samples t test, One-way ANOVA, Pearson's product-moment correlation and level regressions are as follows. (1) Significant differences can be seen in the catalogues of gender, marital status, age, educational level, occupation, average monthly wagers upon impose buying and the impact factors of behavior in the Multi Media Expo.(2) Consumers of various age or occupation have different knowledge level regarding the products. (3) Significant differences of purchase intentions between consumers in various educational levels in the multimedia expo. (4) Positive significant impacts of purchase intentions impacted by impulse buying especially in some promotion ways of advertisement, shopping situation and payment terms. (5) Significant influences of the impact between the consumers¡¦ shopping intentions and product knowledge. (6) Significant impacts in impulse buying personality to impulse shopping behavior and purchasing intention with positive interference between impulse shopping personality and purchasing intention. Negative impact occurs on shopping situation and purchasing intention regarding to impulse buying personality. (7) Significant interference impact on knowledge of products and shopping intention regarding to impulse buying personality. To conclude, except explaining and discussing the applications of the research result, the following suggestions were also mentioned to the exhibitors. (1) Combine marketing policies and product advertisement to raise the marketing performance. (2) Arrange better endorsements to attract the crowds. (3) Flexibly utilize quantitative promotions and main commodities to create a purchasing rush. (4) Properly plan the expo venue and improve the service quality to create situational stimuli. (5) Exercise various paying methods to improve the shopping intention of young people. (6) Make the best use of the consumers¡¦ product knowledge to improve shopping intention. (7) Utilize the interference impact of impulse shopping personality to raise the consumers¡¦ shopping intention. Moreover, some advices for future research were also mentioned.
90

Performance Analysis of Improved Selective-Rake on Ultra-Wideband Channels

Wang, Yan-Lun 23 July 2004 (has links)
The Ultra-Wideband (UWB) communication technology has been extensively attended in recent years. In this thesis, we propose the improved selective-Rake receiver and analyze the performance on UWB channels. The UWB transmission channels are modeled with statistical methods and its fading characteristics are discussed. Different impulse radio properties for the UWB communication system are analyzed. The system performance and design complexity issues of selective-Rake receiver (SRake) are studied. Rake receiver has difficulties achieving desired system performance in the dense multipath environment. The main ideas of SRake receiver are to obtain the SNR level on known multipath channel and to determine the desired number of Rake fingers. Matched filters and maximum likelihood detectors are utilized in the implementation of the SRake to estimate the signal time delay. The CLEAN algorithm is then used in selecting the paths with relatively high energy. Furthermore, we also propose a noise cancellation scheme for performance improvement in the SRake receiver. In the noise cancellation scheme, the multiresolution property of wavelet transform is used for filtering the noise interference caused by the rapid fluctuation factor. In addition, a two-stage search is combined with the original CLEAN algorithm to increase the accuracy of path selection. From our simulation results on the UWB channels, the improved SRake receiver, with noise cancellation and two-stage search, indeed has high SRake output SNR and better path accuracy than the original SRake receiver.

Page generated in 0.0552 seconds