131 research outputs found
On Circuit Complexity Classes and Iterated Matrix Multiplication
In this thesis, we study small, yet important, circuit complexity classes within NC1, such as ACC0 and TC0. We also investigate the power of a closely related problem called Iterated Matrix Multiplication and its implications in low levels of algebraic complexity theory. More concretely, • We show that extremely modest-sounding lower bounds for certain problems can lead to non-trivial derandomization results. – If the word problem over S5 requires constant-depth threshold circuits of size n1+ for some > 0, then any language accepted by uniform polynomial-size probabilis-tic threshold circuits can be solved in subexponential time (and more strongly, can be accepted by a uniform family of deterministic constant-depth threshold circuits of subexponential size.) – If there are no constant-depth arithmetic circuits of size n1+ for the problem of multiplying a sequence of n 3-by-3 matrices, then for every constant d, black-box identity testing for depth-d arithmetic circuits with bounded individual degree can be performed in subexponential time (and even by a uniform family of deterministic constant-depth AC circuits of subexponential size). ii • ACCm circuits are circuits consisting of unbounded fan-in AND, OR and MODm gates and unary NOT gates, where m is a fixed integer. We show that there exists a language in non-deterministic exponential time which can not be computed by any non-uniform family of ACCm circuits of quasi-polynomial size and o(log log n) depth, where m is an arbitrarily chosen constant. • We show that there are families of polynomials having small depth-two arithmetic circuits that cannot be expressed by algebraic branching programs of width two. This clari-fies the complexity of the problem of computing the product of a sequence of two-by-two matrices, which arises in several settings
On the Power of Algebraic Branching Programs of Width Two
We show that there are families of polynomials having small depth two arithmetic circuits that cannot be expressed by algebraic branching programs of width two. This clarifies the complexity of the problem of computing the product of a sequence of two-by-two matrices, which arises in several settings.Peer reviewe
Genomic Mechanisms of Physiological and Morphological Adaptations of Limestone Langurs to Karst Habitats
Abstract
Knowledge of the physiological and morphological evolution and adaptation of nonhuman primates is critical to understand hominin origins, physiological ecology, morphological evolution, and applications in biomedicine. Particularly, limestone langurs represent a direct example of adaptations to the challenges of exploiting a high calcium and harsh environment. Here, we report a de novo genome assembly (Tfra_2.0) of a male François’s langur (Trachypithecus francoisi) with contig N50 of 16.3 Mb and resequencing data of 23 individuals representing five limestone and four forest langur species. Comparative genomics reveals evidence for functional evolution in genes and gene families related to calcium signaling in the limestone langur genome, probably as an adaptation to naturally occurring high calcium levels present in water and plant resources in karst habitats. The genomic and functional analyses suggest that a single point mutation (Lys1905Arg) in the α1c subunit of the L-type voltage-gated calcium channel Cav1.2 (CACNA1C) attenuates the inward calcium current into the cells in vitro. Population genomic analyses and RNA-sequencing indicate that EDNRB is less expressed in white tail hair follicles of the white-headed langur (T. leucocephalus) compared with the black-colored François’s langur and hence might be responsible for species-specific differences in body coloration. Our findings contribute to a new understanding of gene–environment interactions and physiomorphological adaptative mechanisms in ecologically specialized primate taxa
Boundary sliding mode control approach to a one-link flexible beam contact force problem with boundary input disturbances
Evolutionary analysis of three gibberellin oxidase genesin rice, Arabidopsis, and soybean
Video streaming watermarketing
In this thesis, the author studies real-time video streaming watermarking system. A 3-tier architecture that adds a proxy server between the video server and the client's video player is proposed. The proxy server intercepts the client's request and the video data transmitted by the server, embeds a watermark into the video data based on the client/transaction information, and re-encapsulate the video data within the transport packets.Master of Engineerin
Behavioral Traits and Political Selection in Authoritarian Ruling Parties: Evidence from the Chinese Communist Party
This dissertation investigates the role of behavioral factors in the personnel selection in authoritarian ruling parties. First, I argue that authoritarian ruling parties increase the weight of dispositional and behavioral criteria in personnel selection as a response to structural changes. Namely, the reasons behind this shift are that an authoritarian ruling party faces similar problems in personnel selection (such as heterogeneities in agents’ tasks and the multitask problem) and the party can no longer observe members’ and cadres’ loyalty based on a single indicator. Subsequently, I argue that risk attitudes, a key dispositional concept in applied psychology and behavioral politics, explain cadres’ propensities to engage in policy innovation and their obedience to the party leadership's authority and orders. I further examine two mechanisms that might explain the relationship between risk attitudes and obedience, namely sensation-seeking and loss aversion. Finally, I contend that authoritarian ruling parties employ a diversified strategy of personnel selection when they assign cadres to different offices. To test the arguments, the author employs a mixed-method approach and utilizes archival evidence, original cadre survey experiments, original survey data, and interviews in the Chinese Communist Party (CCP), the largest authoritarian ruling party in the world.</p
A Promoter Region Polymorphism in PDCD-1 Gene Is Associated with Risk of Rheumatoid Arthritis in the Han Chinese Population of Southeastern China
Objective. Programmed cell death 1 (PD-1) induces negative signals to T cells during interaction with its ligands and is therefore a candidate gene in the development of autoimmune diseases such as rheumatoid arthritis (RA). Herein, we investigate the association of PDCD-1 polymorphisms with the risk of RA among Chinese patients and healthy controls. Methods. Using the PCR-direct sequencing analysis, 4 PDCD-1 SNPs (rs36084323, rs11568821, rs2227982, and rs2227981) were genotyped in 320 RA patients and 309 matched healthy controls. Expression of PD-1 was determined in peripheral blood lymphocytes by flow cytometry and quantitative real-time reverse transcriptase polymerase chain reaction. Results. We observed that the GG genotype of rs36084323 was associated with a increased risk for developing RA (OR 1.70, 95% 1.11–2.61, P=0.049). Patients carrying G/G genotype displayed an increased mRNA level of PD-1 (P=0.04) compared with A/A genotype and healthy controls. Meanwhile, patients homozygous for rs36084323 had induced basal PD-1 expression on activated CD4+ T cells. Conclusion. The PDCD-1 polymorphism rs36084323 was significantly associated with RA risk in Han Chinese population. This SNP, which effectively influenced the expression of PD-1, may be a biomarker of early diagnosis of RA and a suitable indicator of utilizing PD-1 inhibitor for treatment of RA
A Fuzzy-Based Four-Dimensional Data Assimilation Algorithm for Comprehensive Ocean Observation Information System
Diagnostic challenges of intra‐operative frozen consultation for gastrointestinal signet ring cell carcinoma†
- …
