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Systematic design of high dimensional circular trellis-coded modulation in spread spectrum communicationsSong, Xiangyu January 2001 (has links)
No description available.
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LIBERATORY EXPRESSIONS: BLACK WOMEN, RESISTANCE AND THE CODED WORD, AN AFRICOLOGICAL EXAMINATIONNicholas, Alice Lynn January 2019 (has links)
Word coding can be traced to the ancient Kemetic practice of steganography (referring to hiding place or hidden message). Unless the reader is aware of the meaning, the Coded Word can often appear as just art. Afrocentric scholarship however, also incorporates the idea of functionality. Aesthetics, throughout African history, and to this day, serve a purpose. The beautiful quilts sewn by enslaved Black women served dual functions, as bed coverings and as symbols of resistance and liberation. The decorative wrought-ironwork found on gates and doors throughout the United States serves as a Sankofic reminder and protector. The highly coded language in the aesthetics of the Black Power/Black Arts Movement, shifted paradigms. Though the practice of word coding remains an active part of contemporary Black culture, there is a disconnection between the action and the aim (or function); a direct result of the destructive efforts of colonization. Today’s racially charged and oftentimes dangerous climate calls for a reexamination of word coding as a liberatory tool. I created the theory of the Coded Word to analyze three novels by Black women who are unique in their forms of word coding, just as they are characteristically distinct in their forms of expression. The findings for the three novels have resulted in the first three entries into the Glossary of the Coded Word, a resource to be used by Black people in resistance to oppression and in the struggle for liberation of all Black people. / African American Studies
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Blind Unique Channel Identification of Alamouti Space-Time Coded Channel via a Signalling SchemeZhou, Lin 12 1900 (has links)
<p> In this thesis, we present a novel signalling scheme for blind channel identification of
Alamouti space-time coded (STBC) channel and a space-time coded multiple-input single-output (MISO) system under flat fading environment. By using p-ary and q-ary PSK signals (where p and q are co-prime integers), we prove that a) under a noise-free environment, only two distinct pairs of symbols are needed to uniquely decode the signal and identify the channel, and b) under complex Gaussian noise, if the pth and qth order statistics of the received signals are available, the channel coefficients can also be uniquely determined. In both cases, simple closed-form solutions are derived by exploiting specific properties of the Alamouti STBC code and linear Diophantine equation theory.</p> <p> When only a limited number of received data are available, under Gaussian noise environment, we suggest the use of the semi-definite relaxation method and/or the sphere decoding method to implement blind ML detection so that the joint estimation of the channel and the transmitted symbols can be efficiently facilitated. Simulation results show that blind ML detection methods with our signalling scheme provide superior normalized mean square error in channel estimation compared to the method using only one constellation and that the average symbol error rate is close to that of the coherent detector (which necessitates perfect channel knowledge at the receiver), particularly when the SNR is high.</p> / Thesis / Master of Applied Science (MASc)
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PLAYING TRANSNESS: AN ANALYSIS OF MEANINGFUL TRANSGENDER REPRESENTATION IN VIDEO GAMESMcLaren, Jackson, 0000-0003-0969-3918 08 1900 (has links)
Transgender media representation is generally plagued with problems, and rarely have I experienced transgender media representation where I feel seen, or where I feel as
though it is made from a distinctly transgender-centric perspective. This dissertation
develops a theorization of meaningful transgender representation in video games from the
perspective of transgender people. Meaningful representation entails thoughtfully
included, complex, and trans-coded characters as seen as such by transgender people, and
as such require transgender people to be involved in their creation. Situated between
literature on cultural studies, transgender studies, and game studies, I interrogated the
following research questions: what does meaningful transgender representation look like
in video games? What is involved in making meaningful transgender representation in
games? And what do players think about transgender representation in video games?
Starting autoethnographically from my own experience with trans video game
representation, I used a combination of textual analysis and close reading on eight
characters in video games with significant transgender representation, analyzed paratexts
like published interviews and game wikis, and utilized semi-structured interviews with
three game creators and consultants, one game journalist, and 31 players that had
encountered these eight characters to answer my research questions.
I argue that there are distinctive features of meaningful transgender representation
that include characters being significantly present; characters and their transness being
thoughtfully included in the game; having an alignment being transgender identity,
physical appearance, and voice acting; and characters looking and feeling distinctly
transgender. In addition, I argue that trans involvement is important to crafting
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transgender representation as I found demographic differences in how transgender
players thought of and received these characters in comparison to others. This finding
also signals that transgender audiences are receiving, and therefore thinking about, this
representation in different ways than cisgender or LGBQ players. As explored through
paratexts and interviews with game creators and consultants, game companies that valued
diversity, involved transgender folks in the process of creating these characters, and
prioritized organic inclusion (Christian & White, 2020) created the most meaningful
transgender representation. By offering specific evidence across the textual, producer,
and audience sides, I show that including transgender folks in the creation process leads
to more meaningful representation as read by all players in my sample, as articulated by
folks I talked to and read about in the production process, and in the same way that
transgender characters being incorporated thoughtfully throughout the game leads to
more meaningful transgender representation. Ultimately, meaningful transgender
representation is that which is made by, about, and for transgender audiences.
Meaningful transgender representation offers the possibility for transgender folks to feel
seen and to experience media that feels real; in addition, it encourages cisgender folks to
experience media through a trans-centric gaze. / Media & Communication
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Automatiserade regressionstester avseende arbetsflöden och behörigheter i ProjectWise. : En fallstudie om ProjectWise på Trafikverket / Automated regression tests regarding workflows and permissions in ProjectWise.Ograhn, Fredrik, Wande, August January 2016 (has links)
Test av mjukvara görs i syfte att se ifall systemet uppfyller specificerade krav samt för att hitta fel. Det är en viktig del i systemutveckling och involverar bland annat regressionstestning. Regressionstester utförs för att säkerställa att en ändring i systemet inte medför att andra delar i systemet påverkas negativt. Dokumenthanteringssystem hanterar ofta känslig data hos organisationer vilket ställer höga krav på säkerheten. Behörigheter i system måste därför testas noggrant för att säkerställa att data inte hamnar i fel händer. Dokumenthanteringssystem gör det möjligt för flera organisationer att samla sina resurser och kunskaper för att nå gemensamma mål. Gemensamma arbetsprocesser stöds med hjälp av arbetsflöden som innehåller ett antal olika tillstånd. Vid dessa olika tillstånd gäller olika behörigheter. När en behörighet ändras krävs regressionstester för att försäkra att ändringen inte har gjort inverkan på andra behörigheter. Denna studie har utförts som en kvalitativ fallstudie vars syfte var att beskriva utmaningar med regressionstestning av roller och behörigheter i arbetsflöden för dokument i dokumenthanteringssystem. Genom intervjuer och en observation så framkom det att stora utmaningar med dessa tester är att arbetsflödens tillstånd följer en förutbestämd sekvens. För att fullfölja denna sekvens så involveras en enorm mängd behörigheter som måste testas. Det ger ett mycket omfattande testarbete avseende bland annat tid och kostnad. Studien har riktat sig mot dokumenthanteringssystemet ProjectWise som förvaltas av Trafikverket. Beslutsunderlag togs fram för en teknisk lösning för automatiserad regressionstestning av roller och behörigheter i arbetsflöden åt ProjectWise. Utifrån en kravinsamling tillhandahölls beslutsunderlag som involverade Team Foundation Server (TFS), Coded UI och en nyckelordsdriven testmetod som en teknisk lösning. Slutligen jämfördes vilka skillnader den tekniska lösningen kan utgöra mot manuell testning. Utifrån litteratur, dokumentstudie och förstahandserfarenheter visade sig testautomatisering kunna utgöra skillnader inom ett antal identifierade problemområden, bland annat tid och kostnad. / Software testing is done in order to see whether the system meets specified requirements and to find bugs. It is an important part of system development and involves, among other things, regression testing. Regression tests are performed to ensure that a change in the system does not affect other parts of the system adversely. Document management systems often deals with sensitive data for organizations, which place high demands on safety. Permissions in the system has to be tested thoroughly to ensure that data does not fall into the wrong hands. Document management systems make it possible for organizations to pool their resources and knowledge together to achieve common goals. Common work processes are supported through workflows that contains a variety of states. These different permissions apply to different states. When a permission changes regression tests are required to ensure that the changes has not made an impact on other permissions. This study was conducted as a qualitative case study whose purpose was to describe the challenges of regression testing of roles and permissions in document workflows in a document management system. Through interviews and an observation it emerged that the major challenges of these tests is that workflow states follow a predetermined sequence. To complete this sequence, a huge amount of permissions must be tested. This provides a very extensive test work that is time consuming and costly. The study was directed toward the document management system ProjectWise, managed by Trafikverket. Supporting documentation for decision making was produced for a technical solution for automated regression testing of roles and permissions in workflows for ProjectWise. Based on a requirement gathering decision-making was provided that involved the Team Foundation Server (TFS), Coded UI and a keyword-driven test method for a technical solution. Finally, a comparison was made of differences in the technical solution versus today's manual testing. Based on literature, document studies and first hand experiences, test automation provides differences in a number of problem areas, including time and cost.
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ON SYMBOL TIMING RECOVERY IN ALL-DIGITAL RECEIVERSGhrayeb, Ali A. 10 1900 (has links)
International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Sandia National Laboratories (SNL) currently achieves a bandwidth efficiency (h ) of 0.5 to 1.0 bps/Hz by using traditional modulation schemes, such as, BPSK and QFSK. SNL has an interest in increasing the present bandwidth efficiency by a factor of 4 or higher with the same allocated bandwidth (about 10 MHz). Simulations have shown that 32- QAM trellis-coded modulation (TCM) gives a good bit error rate (BER) performance, and meets the requirements as far as the bandwidth efficiency is concerned. Critical to achieving this is that the receiver be able to achieve timing synchronization. This paper examines a particular timing recovery algorithm for all-digital receivers. Timing synchronization in a digital receiver can be achieved in different ways. One way of achieving this is by interpolating the original sampled sequence to produce another sampled sequence synchronized to the symbol rate or a multiple of the symbol rate. An adaptive sampling conversion algorithm which performs this function was developed by Floyd Gardner in 1993. In the present work, his algorithm was applied to two different modulation schemes, BPSK and 4-ary PAM. The two schemes were simulated in the presence of AWGN and ISI along with Gardner’s algorithm for timing recovery, and a fractionally spaced equalizer (T/2 FSE) for equalization. Simulations show that the algorithm gives good BER performance for BPSK in all the situations, and at different sampling frequencies, but unfortunately poor performance for the 4-ary PAM scheme. This indicates that Gardner’s algorithm for sampling conversion is not suitable for multi-level signaling schemes.
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Nonbinary-LDPC-Coded Modulation Schemes for High-Speed Optical Communication NetworksArabaci, Murat January 2010 (has links)
IEEE has recently finished its ratification of the IEEE Standard 802.3ba in June 2010 which set the target Ethernet speed as 100 Gbps. The studies on the future trends of the ever-increasing demands for higher speed optical fiber communications show that there is no sign of decline in the demand. Constantly increasing internet traffic and the bandwidth-hungry multimedia services like HDTV, YouTube, voice-over-IP, etc. can be shown as the main driving forces. Indeed, the discussions over the future upgrades on the Ethernet speeds have already been initiated. It is predicted that the next upgrade will enable 400 Gbps Ethernet and the one after will be toward enabling the astounding 1 Tbps Ethernet.Although such high and ultra high transmission speeds are unprecedented over any transmission medium, the bottlenecks for achieving them over the optical fiber remains to be fundamental. At such high operating symbol rates, the signal impairments due to inter- and intra-channel fiber nonlinearities and polarization mode dispersion get exacerbated to the levels that cripple the high-fidelity communication over optical fibers. Therefore, efforts should be exerted to provide solutions that not only answer the need for high-speed transmission but also maintain low operating symbol rates.In this dissertation, we contribute to these efforts by proposing nonbinary-LDPC-coded modulation (NB-LDPC-CM) schemes as enabling technologies that can meet both the aforementioned goals. We show that our proposed NB-LDPC-CM schemes can outperform their prior-art, binary counterparts called bit-interleaved coded modulation (BI-LDPC-CM) schemes while attaining the same aggregate bit rates at a lower complexity and latency. We provide comprehensive analysis on the computational complexity of both schemes to justify our claims with solid evidence. We also compare the performances of both schemes by using amplified spontaneous emission (ASE) noise dominated optical fiber transmission and short to medium haul optical fiber transmission scenarios. Both applications show outstanding performances of NB-LDPC-CM schemes over the prior-art BI-LDPC-CM schemes with increasing gaps in coding gain as the transmission speeds increase. Furthermore, we present how a rate-adaptive NB-LDPC-CM can be employed to fully utilize the resources of a long haul optical transport network throughout its service time.
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X-ray Coherent Scatter Imaging for Intra-operative Margin Detection in Breast Conserving SurgeriesLakshmanan, Manu Nachiappan January 2015 (has links)
<p>One of the challenges facing clinical practice today is intra-operative margin detection in breast conserving surgeries (BCS) or lumpectomy procedures. When a surgeon removes a breast tumor from a patient during a BCS procedure, the surgically excised tissue specimen is examined to see whether it contains a margin of healthy tissue around the tumor. A healthy margin of tissue around the tumor would indicate that the tumor in its entirety has been removed. On the other hand, if cancerous tissue is at the surface of the specimen, that would indicate that the tumor may have been transected during the procedure, leaving some residual cancerous tissue inside the patient. The most effective intra-operative real-time margin detection techniques currently used in clinical practice are frozen section analysis (FSA) and touch-prep cytology. These methods have been shown to possess inconsistent accuracy, which result in 20% to 30% of BCS patients being called back for a repeat BCS procedure to remove the residual tumor tissue. In addition these techniques have been shown to be time-consuming--requiring the operating room team to have to wait at least 20 minutes for the results. Therefore, there is a need for accurate and faster technology for intra-operative margin detection. </p><p>In this dissertation, we describe an x-ray coherent scatter imaging technique for intra-operative margin detection with greater accuracy and speed than currently available techniques. The method is based on cross-sectional imaging of the differential coherent scatter cross section in the sample. We first develop and validate a Monte Carlo simulation of coherent scattering. Then we use that simulation to design and test coherent scatter computed tomography (CSCT) and coded aperture coherent scatter spectral imaging (CACSSI) for cancerous voxel detection and for intra-operative margin detection using (virtual) clinical trials. Finally, we experimentally implement a CACSSI system and determine its accuracy in cancer detection using tissue histology. </p><p>We find that CSCT and CACSSI are able to accurately detect cancerous voxels inside of breast tissue specimens and accurately perform intra-operative margin detection. Specifically, for the task of individual cancerous voxel detection, we show that CSCT and CACSSI have AUC values of 0.97 and 0.94, respectively. Whereas for the task of intra-operative margin detection, the results of our virtual clinical trials show that CSCT and CACSSI have AUC values of 0.975 and 0.741, respectively. The gap in spatial resolution between CSCT and CACSSI affects the results of intra-operative margin detection much more than it does the task of individual cancerous voxel detection. Finally, we also show that CSCT would require on the order of 30 minutes to create a 3D image of a breast cancer specimen, whereas CACSSI would require on the order of 3 minutes. </p><p>These results of this work show that coherent scatter imaging has the potential to provide more accurate intra-operative margin detection than currently used clinical techniques. In addition, the speed (and therefore low scan duration: 3 min) of CACSSI, along with its ability to automatically classify cancerous tissue for margin detection means that coherent scatter imaging would be much more cost-effective than the clinical techniques that require up to 20 minutes and a trained pathologist. With the cancerous voxel detection accuracy of a 0.94 AUC and scan time of on the order of 3 minutes demonstrated for coherent scatter imaging in this work, coherent scatter imaging has the potential to reduce healthcare costs for BCS procedures and rates of repeat BCS surgeries. The accuracy for CACSSI can be considerably improved to match CSCT accuracy by improving its spatial resolution through a number of techniques: incorporating into the CACSSI reconstruction algorithm the ability to differentiate noise from high frequency signal so that we can image with higher frequency coded aperture masks; implementing a 2D coded aperture mask with a 2D detector; or acquiring additional angles of projection data.</p> / Dissertation
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Coded Aperture Magnetic Sector Mass SpectrometryRussell, Zachary Eugene January 2015 (has links)
<p>Mass spectrometry is widely considered to be the gold standard of elemental analysis techniques due to its ability to resolve atomic and molecular and biological species. Expanding the application space of mass spectrometry often requires the need for portable or hand-held systems for use in field work or harsh environments. While only requiring “sufficient” mass resolution to meet the needs of their application space, these miniaturized systems suffer from poor signal to background ratio which limits their sensitivity as well as their usefulness in field applications. </p><p>Spatial aperture coding techniques have been used in optical spectroscopy to achieve large increases in signal intensity without compromising system resolution. In this work similar computational methods are used in the application of these techniques to the field of magnetic sector mass spectrometry. Gains in signal intensity of 10x and 4x were achieved for 1D and 2D coding techniques (respectively) using a simple 90 degree magnetic sector test setup. Initial compatibility with a higher mass resolution double focusing Mattauch-Herzog mass spectrograph is demonstrated experimentally and with high fidelity particle tracing simulations. A novel electric sector lens system was designed to stigmate high order coded aperture patterned beam which shows simulated gains in signal intensity of 50x are achievable using these techniques.</p> / Dissertation
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Genetické algoritmy v evoluční robotice / Genetic algorithms in evolutionary roboticsMašek, Michal January 2011 (has links)
Through series of experiments this work compares effects of different types of genetic algorithms on evolution of a neural network that is used to control a robot. Genetic algorithms using binary and real coded individuals, algorithms using basic and advanced mutations and crossovers and algorithms using fixed and variable population size are compared on three tasks of evoltionary robotics. The goal is to determine wether usage of advanced genetic algorithms leads to faster convergence or to better solution than usage of basic genetic algorithm. Experiments are performed in an easily extendable simulator developed for purposes of this work.
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