2,510 research outputs found
Non-Abelian (Hyperscaling Violating) Lifshitz Black Holes in General Dimensions
We consider Einstein gravities coupled to a cosmological constant and
multiple Yang-Mills fields in general dimensions and find that the
theories admit colored Lifshitz solutions with dynamic exponents . We also
introduce a Maxwell field and construct exact electric charged black holes that
asymptote to the colored Lifshitz spacetimes and analyse their
thermodynamical first law. Furthermore, we introduce a dilaton to the system
and construct Lifshitz spacetimes with hyperscaling violations. After turning
on the Maxwell field, we obtain a class of hyperscaling violating Lifshitz
black holes when .Comment: Latex, 12 pages, a published version in PL
Strolling through the Enchanting Back Garden of the HeartBook Review: Philosophical Poetry in Ancient China Translated by Han Wei
In a state of excitement, I opened this long-anticipated Philosophical Poetry in Ancient China, and my memories seemed to instantly transport me back to that brilliant and affectionate old dream. The first time I encountered Dr. Han Wei’s work was in 2016 when I had just arrived in Guilin. At that time, facing the world’s unparalleled picturesque mountains and serene rivers outside my window, hearing the gentle drizzle in the spring breeze, and breathing in the elegant and mellow aroma of osmanthus, all my senses became acutely attuned. The dormant dreams within me reawakened, and the inspirations that leaped in my heart were no longer mere dust stirred by the northern winds..
Reliability and security in low power circuits and systems
With the massive deployment of mobile devices in sensitive areas such as healthcare and defense, hardware reliability and security have become hot research topics in recent years. These topics, although different in definition, are usually correlated. This dissertation offers an in-depth treatment on enhancing the reliability and security of low power circuits and systems. The first part of the dissertation deals with the reliability of sub-threshold designs, which use supply voltage lower than the threshold voltage (Vth) of transistors to reduce power. The exponential relationship between delay and Vth significantly jeopardizes their reliability due to process variation induced timing violations. In order to address this problem, this dissertation proposes a novel selective body biasing scheme. In the first work, the selective body biasing problem is formulated as a linearly constrained statistical optimization model, and the adaptive filtering concept is borrowed from the signal processing community to develop an efficient solution. However, since the adaptive filtering algorithm lacks theoretical justification and guaranteed convergence rate, in the second work, a new approach based on semi-infinite programming with incremental hypercubic sampling is proposed, which demonstrates better solution quality with shorter runtime. The second work deals with the security of low power crypto-processors, equipped with Random Dynamic Voltage Scaling (RDVS), in the presence of Correlation Power Analysis (CPA) attacks. This dissertation firstly demonstrates that the resistance of RDVS to CPA can be undermined by lowering power supply voltage. Then, an alarm circuit is proposed to resist this attack. However, the alarm circuit will lead to potential denial-of-service due to noise-triggered false alarms. A non-zero sum game model is then formulated and the Nash Equilibria is analyzed --Abstract, page iii
Book Review: Dire Straits-Education Reforms: Ideology, Vested Interests and Evidence by Montserrat Gomendio and José Ignacio Wert
Education, as a practical activity to improve the comprehensive quality of human beings, not only plays a role in the transmission and inheritance of culture but also has intimate ties to the growth of life and development of economy and society. In this book, the authors Montserrat Gomendio and José Ignacio Wert discuss the reasons why education reforms are difficult to implement but easy to reverse, taking into account the valuable evidence they have obtained in designing and implementing education reforms in Spain and their subsequent experience at the OECD (Organization for Economic Cooperation and Development) advising governments worldwide. This dialogue on education is like a breath of fresh air for the reader. By comparing education policies from an international perspective and analyzing the interplay between education reforms, ideology and vested interests, the authors provide insights into the positive and negative factors that influence education reforms. The book consists of seven chapters
Session-Based Recommendation by Exploiting Substitutable and Complementary Relationships from Multi-behavior Data
Session-based recommendation (SR) aims to dynamically recommend items to a
user based on a sequence of the most recent user-item interactions. Most
existing studies on SR adopt advanced deep learning methods. However, the
majority only consider a special behavior type (e.g., click), while those few
considering multi-typed behaviors ignore to take full advantage of the
relationships between products (items). In this case, the paper proposes a
novel approach, called Substitutable and Complementary Relationships from
Multi-behavior Data (denoted as SCRM) to better explore the relationships
between products for effective recommendation. Specifically, we firstly
construct substitutable and complementary graphs based on a user's sequential
behaviors in every session by jointly considering `click' and `purchase'
behaviors. We then design a denoising network to remove false relationships,
and further consider constraints on the two relationships via a particularly
designed loss function. Extensive experiments on two e-commerce datasets
demonstrate the superiority of our model over state-of-the-art methods, and the
effectiveness of every component in SCRM.Comment: 31 pages,11 figures, accepted by Data Mining and Knowledge
Discovery(2023
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