346 research outputs found
On Circuit Complexity Classes and Iterated Matrix Multiplication
No full textIn 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
No full textWe 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
Impacts of shale gas wastewater leaks on neighboring crops: Physiological and morphological responses of tomatoes
No full textAs shale gas extraction expands, the volume of flowback and produced water (FPW) from hydraulic fracturing increases, raising concerns about the potential ecological risks of leaks. In this work, we mixed tap water with different proportions of FPW to simulate various leak scenarios. Tomatoes were irrigated using these mixtures or using FPW treated with multi-stage pre-treatment and advanced membrane technologies to assess the effects on tomato seed germination, plant vigor, element accumulation, and fruit gene expression. Compared to tap water irrigation, all three dilution ratios of FPW inhibited seed germination and growth to varying degrees, significantly reduced tomato biomass and fruit yield, and caused the fruit to exceed safe limits for Pb and Cr. In the lowest dilution group, the germination rate was only 17 %, and total biomass decreased by 55 %. Even in the highest dilution group, fruit yield was 11 % lower than the control. Additionally, the dilution showed high salt accumulation toxicity, with yellowing at the edges of the leaves. Applying treated FPW accelerated tomato growth and increased the yield of tomato hairs, with total biomass rising by 38 %. Finally, a large number of differentially expressed genes were detected in the fruits irrigated with FPW. These genes are irelated to carbon and nitrogen metabolism, affecting the synthesis of carbohydrates and proteins. These findings provide insights into the risks associated with shale gas FPW leakage and offer guidance for the reuse of treated FPW
Genomic Mechanisms of Physiological and Morphological Adaptations of Limestone Langurs to Karst Habitats
No full textAbstract
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
Video streaming watermarketing
No full textIn 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
Unsolved Problems in Special and General Relativity
No full textThis book includes 21 papers written by 23 authors and co-authors: Hua Di, Li Zifeng, Li Wen-Xiu, Shi Yong-Cheng, Xu Jianmin, Dong Jingfeng, Duan Zhongxiao, Fu Yuhua, Guo Kaizhe, Guo Chongwu, Guo Ying-Huan, Guo Zhen-Hua, Hu Chang-Wei, Jiang Chun-Xuan, Liu Taixiang, Tu Runsheng, Wu Fengming, Yang Shijia, Cao Shenglin, Leo G. Sapogin, V. A. Dzhanibekov, Yu. A. Ryabov, and Florentin Smarandache.
The editors hope that all these papers will contribute to the advance of scholarly research on several aspects of Special and General Relativity. This book is suitable for students and scholars interested in studies of physics
Behavioral Traits and Political Selection in Authoritarian Ruling Parties: Evidence from the Chinese Communist Party
No full textThis 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
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