The Body Beautiful: Jonathan Spence’s Final Reith Lecture

Jonathan Spence gave his fourth and last Reith lecture on “The Body Beautiful.” This is a perfect fit for China’s Olympic year and a wonderful conclusion talk after his first lecture on mind (“Confucian Ways”), then on Chinese interactions with the former superpower (the second lecture “English Lessons”), and the current one (the third lecture “American Dreams”). From mind to body, from China as an ancient civilization through its turbulent relations with Western powers to a nation which is determined to compete with the world in hard power either economically or physically, the topic was extremely well thought. The lecture was given at no better venue: Lord’s Cricket Ground, London, which will play an important role in the 2012 London Olympic Games, according to the host of the lecture. Everything seems great. The 2008 BBC’s Reith lecturer entertained us with a brilliant explanation on issues such as ancient Chinese discussions of sports and athleticism, their practices of women’s Polo and men’s kickball roughly one thousand years ago, modern meets in the 20th century, and, most importantly, this year’s Olympics and its implications. His lecture also dealt with the transition from sports for the sake of personal character to sports in the name of nationalism. This is a great treat from a master. Listening to Spence’s many lectures always reminded me of Lao Zi’s political idea: “治大国若烹小鲜,” or it is the same to rule a big nation as to cook a small fish. Any topics for Spence, including this one, seem so easy for him to address, just like cooking a shrimp. But it is exactly Spence’s brilliance that presented some problems for this lecture. As Daoist theory points out, misfortune can become a base of fortune, and fortune can lead to failure. In the short presentation, Spence dazzled us with all the great stuff, and like a talented chef, served us a delicious dish. But for some of us who are greedy, that dish tasted so good that we wanted more—a feast. For instance, Spence explained in a relatively detailed way China’s past participations in Olympic Games and touched upon the issue between Taipei and Beijing of who should represent China in the Olympic family. But he did not elaborate on Beijing’s withdrawal from the Olympic movement nor the PRC’s absence for over two decades from the most of the world’s sports activities

China’s National Representation and the Two-China Question in the Olympic Movement

This paper, through a case study of Beijing’s involvement in the 1952 Helsinki Olympic Games, provides a crucial historical analysis of China’s current obsession with the Olympic movement and the ongoing Beijing/Taipei dispute over the national representation issue. It demonstrates that both Beijing’s all-out campaign for the 2008 Games and the argument across the Strait about who should or should not represent China are nothing new, and are rooted in past experience

La représentation nationale de la China et la question des deux Chine dans le mouvement olympique

Cet article, à travers l’étude du cas de la participation de Pékin aux jeux Olympiques de 1952 à Helsinki, offre une analyse historique cruciale pour comprendre l’actuelle obsession olympique de la Chine et le conflit toujours actif entre Pékin et Taipei sur la question de la représentation nationale. Il démontre que tant la forte campagne menée par Pékin pour obtenir les Jeux de 2008 que le débat sur la question de savoir qui doit ou ne doit pas représenter la Chine ne sont pas nouveaux et prennent leurs racines dans les controverses passées

NP-Hardness of Tensor Network Contraction Ordering

We study the optimal order (or sequence) of contracting a tensor network with a minimal computational cost. We conclude 2 different versions of this optimal sequence: that minimize the operation number (OMS) and that minimize the time complexity (CMS). Existing results only shows that OMS is NP-hard, but no conclusion on CMS problem. In this work, we firstly reduce CMS to CMS-0, which is a sub-problem of CMS with no free indices. Then we prove that CMS is easier than OMS, both in general and in tree cases. Last but not least, we prove that CMS is still NP-hard. Based on our results, we have built up relationships of hardness of different tensor network contraction problems.Comment: Jianyu Xu and Hanwen Zhang are equal contributors. 10 pages (reference and appendix excluded), 20 pages in total, 6 figure

Inherent Redundancy in Spiking Neural Networks

Spiking Neural Networks (SNNs) are well known as a promising energy-efficient alternative to conventional artificial neural networks. Subject to the preconceived impression that SNNs are sparse firing, the analysis and optimization of inherent redundancy in SNNs have been largely overlooked, thus the potential advantages of spike-based neuromorphic computing in accuracy and energy efficiency are interfered. In this work, we pose and focus on three key questions regarding the inherent redundancy in SNNs. We argue that the redundancy is induced by the spatio-temporal invariance of SNNs, which enhances the efficiency of parameter utilization but also invites lots of noise spikes. Further, we analyze the effect of spatio-temporal invariance on the spatio-temporal dynamics and spike firing of SNNs. Then, motivated by these analyses, we propose an Advance Spatial Attention (ASA) module to harness SNNs' redundancy, which can adaptively optimize their membrane potential distribution by a pair of individual spatial attention sub-modules. In this way, noise spike features are accurately regulated. Experimental results demonstrate that the proposed method can significantly drop the spike firing with better performance than state-of-the-art SNN baselines. Our code is available in \url{https://github.com/BICLab/ASA-SNN}.Comment: Accepted by ICCV202

Spike-driven Transformer

Spiking Neural Networks (SNNs) provide an energy-efficient deep learning option due to their unique spike-based event-driven (i.e., spike-driven) paradigm. In this paper, we incorporate the spike-driven paradigm into Transformer by the proposed Spike-driven Transformer with four unique properties: 1) Event-driven, no calculation is triggered when the input of Transformer is zero; 2) Binary spike communication, all matrix multiplications associated with the spike matrix can be transformed into sparse additions; 3) Self-attention with linear complexity at both token and channel dimensions; 4) The operations between spike-form Query, Key, and Value are mask and addition. Together, there are only sparse addition operations in the Spike-driven Transformer. To this end, we design a novel Spike-Driven Self-Attention (SDSA), which exploits only mask and addition operations without any multiplication, and thus having up to $87.2\times$ lower computation energy than vanilla self-attention. Especially in SDSA, the matrix multiplication between Query, Key, and Value is designed as the mask operation. In addition, we rearrange all residual connections in the vanilla Transformer before the activation functions to ensure that all neurons transmit binary spike signals. It is shown that the Spike-driven Transformer can achieve 77.1\% top-1 accuracy on ImageNet-1K, which is the state-of-the-art result in the SNN field. The source code is available at https://github.com/BICLab/Spike-Driven-Transformer

The Mollow triplets under few-photon excitation

Resonant excitation is an essential tool in the development of semiconductor quantum dots (QDs) for quantum information processing. One central challenge is to enable a transparent access to the QD signal without post-selection information loss. A viable path is through cavity enhancement, which has successfully lifted the resonantly scattered field strength over the laser background under \emph{weak} excitation. Here, we extend this success to the \emph{saturation} regime using a QD-micropillar device with a Purcell factor of 10.9 and an ultra-low background cavity reflectivity of just 0.0089. We achieve a signal to background ratio of 50 and an overall system responsivity of 3~\%, i.e., we detect on average 0.03 resonantly scattered single photons for every incident laser photon. Raising the excitation to the few-photon level, the QD response is brought into saturation where we observe the Mollow triplets as well as the associated cascade single photon emissions, without resort to any laser background rejection technique. Our work offers a new perspective toward QD cavity interface that is not restricted by the laser background.Comment: 8 Figures and 9 Pages. Comments are welcom

Replacing fossil fuels wtih solar energy in an SME in UK and Kurdistan, Iraq: Kansas fried chicken case study

Energy management and analysis are more common in large companies since they have the resources and commitment to assign such tasks to employee compared to SMEs. Only a very small proportion of the overall business costs pertains to energy requirements and therefore SMEs pay little attention to energy analysis and management. Fossil fuels, which cause issues related to global warming, can viably be replaced with renewable energy sources such as solar energy. Trends in solar cell development are likely to yield a potential solution to problems generated by an over reliance on fossil fuels. Solar solutions are relatively simple to implement in SMEs than in large corporation and the combined impact small businesses is likely to be much greater. A micro-business has been utilized as a cases study for the purposes of illustration in the UK and Kurdistan-Iraq. Even though Kurdistan-Iraq is abundant in oil and gas, its climatic favour the implementation of solar cells which can replace the existing use of non-renewable fossil fuel. Our comparative study suggests that solar can replaced a reasonable amount of the energy needs even in the UK and a much higher amount in Kurdistan-Iraq. Using 20% efficient solar, can replace 23% and 70% of the energy requirements of the microbusiness in UK and Kurdistan-Iraq respectively