1,131 research outputs found
Symphony No.2 and the Text Setting of Henry Purcell\u27s Dido and Aeneas
This work is conceived as a unit that has two parts. Part one is an original composition, Symphony No. 2. This piece is scored for symphony orchestra and it is a sequel of the composerās master thesis, a symphonic poem titled Moonlight Sprite, which describes the various landscapes of imaginary sprites in nature. The compositional techniques include whole tone scale, octatonic scale, pentatonic scale, atonality, bitonality, polytonality, tone clusters, and minimalism. The pieceās orchestration style and techniques are mainly influenced by Stravinsky, Bartok, Schoenberg, Webern, Penderecki, Charles Ives, and Dinos Constantinides.
Part two is an analysis of the text setting of Henry Purcellās opera, Dido and Aeneas. After exploring Purcellās biography, the characteristics of the Baroque music period, and all of Purcellās works across different genres, this study meticulously analyzes his musical devices for text setting and provides score examples. Ultimately, the analysis reveals Purcellās effective use of ascending and descending melodic lines to represent the text phrasesā various moods or feelings, embellishments to express the nuance of the words, and harmonic structures to support the atmosphere of various scenes. The analysis emphasizes the importance of Dido and Aeneas as a piece of English Baroque theater music in Western music history. In addition, this dissertation draws attention to a misprinting of Ellen Harrisā score edition of Dido and Aeneas, thereby providing Oxford University Press with an opportunity to correct it. Henry Purcellās compositional techniques such as ascending and descending melodic lines, bass ostinato, and harmonic structure in Dido and Aeneas are reinterpreted and used in Symphony No. 2. Thus, Dido and Aeneas and Symphony No. 2 share some compositional devices
First-Principles Study Of Semiconductor And Metal Surfaces
In this dissertation, we study the electronic and geometric structure of semiconductors and metal surfaces based on quantum mechanical first-principles calculations. We determine the geometry of vacancy defects of hydrogen adsorbed on a Pd(111) surface by treating the motion of a hydrogen atom, in addition to electrons, quantum mechanically. The calculated ground state wave function has high probability density in the hcp site located at the center of the vacancy instead of the fcc sites where the potential is minimum and hydrogen atoms on a Pd(111) surface normally adsorb. The geometry of quantum mechanically determined divacancy provides a simple and clear explanation for the scanning tunneling microscopy (STM) images of these defects that appear as three-lobed objects as observed in recent experiments [Mitsui, et al, Nature 422, 705 (2003)]. We employ the same principle to successfully elucidate the STM images of larger size vacancy defects. Our model also provides a compelling argument to explain the unusual recent experimental result that aggregates of three or more hydrogen vacancies are much more active in adsorption of hydrogen molecules while two-vacancy defects are never inactive. The InAs (110) surfaces appear lower than GaSb in STM images. This height difference is caused primarily by differences in the electronic structure of the two materials according to our calculations in a good agreement with measurements. In contrast, local variations in the apparent height of (110) surface atoms at InSb- or GaAs-like interfaces arise primarily from geometric distortions associated with local differences in bond length. The arsenic atoms adsorb preferably at the bridge sites between the dimerized Sb atoms on Sb-terminating (001) surfaces. Indium atoms, on the other hand, have somewhat equal probabilities at a few different sites on Ga-terminating (001) surfaces. Our calculated energies for atomic intermixing indicate that anion exchanges are exothermic for As atoms on Ga-terminating (001) interfaces but endothermic for In atoms on Sb-terminating (001) interfaces. This difference may explain why GaAs interfaces are typically more disordered than InSb interfaces in these heterostructures
Ground-state structure of the hydrogen double vacancy on Pd(111)
We determine the ground-state structure of a double vacancy in a hydrogen
monolayer on the Pd(111) surface. We represent the double vacancy as a triple
vacancy containing one additional hydrogen atom. The potential-energy surface
for a hydrogen atom moving in the triple vacancy is obtained by
density-functional theory, and the wave function of the fully quantum hydrogen
atom is obtained by solving the Schr\"odinger equation. We find that an H atom
in a divacancy defect experiences significant quantum effects, and that the
ground-state wave function is centered at the hcp site rather than the fcc site
normally occupied by H atoms on Pd(111). Our results agree well with scanning
tunneling microscopy images.Comment: 5 pages, 3 figure
Empirical Rationalization of Prior Substantiation Doctrine: Federal Trade Commission v. Reebok & Sketchers
Companies frequently make efficacy claims in advertisements to introduce new products featuring innovative technology. When such claims are supported by information obtained from scientific research or expert testimonials, they are subject to the doctrine of prior substantiation. Under the doctrine, an advertisement claim based on seemingly credible authorities must be substantiated by a reasonable basis before it is released to the general public. Otherwise, the advertisement will be in violation of Section 5(a) of the Federal Trade Commission Act that prohibits unfair or deceptive acts affecting commerce. \u27 This study investigates the rationale of the legal rule in light of consumer behavior theories. While the doctrine has been normatively rationalized, it has not been empirically examined. Given the paucity of relevant research, this study will test consumer attitudes and cognitive reactions toward different types of advertisement messages, such as, one with establishment claims and the other without such cognitive contents. The study administered real advertising video clips used by Reebok and Sketchers, disputed in two settled cases where the Federal Trade Commission alleged that the defendants failed to satisfy the legal standard of the substantiation rule. The findings of this study support the rationale of the rule on the ground that the Reebok advertisement clip delivering expressive establishment claims about its product efficacy would likely have more of an immediate impact on consumers\u27 purchasing intention than Sketchers\u27 ad without such cognitive information. Implications and future research along with limitations are also discussed
Structure of AlSb(001) and GaSb(001) Surfaces Under Extreme Sb-rich Conditions
We use density-functional theory to study the structure of AlSb(001) and
GaSb(001) surfaces. Based on a variety of reconstruction models, we construct
surface stability diagrams for AlSb and GaSb under different growth conditions.
For AlSb(001), the predictions are in excellent agreement with experimentally
observed reconstructions. For GaSb(001), we show that previously proposed model
accounts for the experimentally observed reconstructions under Ga-rich growth
conditions, but fails to explain the experimental observations under Sb-rich
conditions. We propose a new model that has a substantially lower surface
energy than all (nx5)-like reconstructions proposed previously and that, in
addition, leads to a simulated STM image in better agreement with experiment
than existing models. However, this new model has higher surface energy than
some of (4x3)-like reconstructions, models with periodicity that has not been
observed. Hence we conclude that the experimentally observed (1x5) and (2x5)
structures on GaSb(001) are kinetically limited rather than at the ground
state.Comment: 6 pages, 6 figure
Adjacent Infrared Multitarget Detection Using Robust Background Estimation
Small target detection is very important for infrared search and track (IRST) problems. Grouped targets are difficult to detect using the conventional constant false alarm rate (CFAR) detection method. In this study, a novel multitarget detection method was developed to identify adjacent or closely spaced small infrared targets. The neighboring targets decrease the signal-to-clutter ratio in hysteresis threshold-based constant false alarm rate (H-CFAR) detection, which leads to poor detection performance in cluttered environments. The proposed adjacent target rejection-based robust background estimation can reduce the effects of the neighboring targets and enhance the small multitarget detection performance in infrared images by increasing the signal-to-clutter ratio. The experimental results of the synthetic and real adjacent target sequences showed that the proposed method produces an upgraded detection rate with the same false alarm rate compared to the recent target detection methods (H-CFAR, Top-hat, and TDLMS).111Ysciescopu
B+-tree Index Optimization by Exploiting Internal Parallelism of Flash-based Solid State Drives
Previous research addressed the potential problems of the hard-disk oriented
design of DBMSs of flashSSDs. In this paper, we focus on exploiting potential
benefits of flashSSDs. First, we examine the internal parallelism issues of
flashSSDs by conducting benchmarks to various flashSSDs. Then, we suggest
algorithm-design principles in order to best benefit from the internal
parallelism. We present a new I/O request concept, called psync I/O that can
exploit the internal parallelism of flashSSDs in a single process. Based on
these ideas, we introduce B+-tree optimization methods in order to utilize
internal parallelism. By integrating the results of these methods, we present a
B+-tree variant, PIO B-tree. We confirmed that each optimization method
substantially enhances the index performance. Consequently, PIO B-tree enhanced
B+-tree's insert performance by a factor of up to 16.3, while improving
point-search performance by a factor of 1.2. The range search of PIO B-tree was
up to 5 times faster than that of the B+-tree. Moreover, PIO B-tree
outperformed other flash-aware indexes in various synthetic workloads. We also
confirmed that PIO B-tree outperforms B+-tree in index traces collected inside
the Postgresql DBMS with TPC-C benchmark.Comment: VLDB201
- ā¦