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1.
It is shown that a planar cubic graph can always be reduced to another planar cubic graph with fewer vertices. It is also shown that if a planar cubic graph is edge-3- colorable then the reduction of the number of its vertices is possible without changing colors of its edges.  相似文献   

2.
Consider the multi-user virtual worlds of online games such as EVE and World of Warcraft, or the multi-user virtual world of Second Life. Suppose a player performs an action in one of these worlds, via his or her virtual character, which would be wrong, if the virtual world were real. What is the moral status of this virtual action? In this paper I consider arguments for and against the Asymmetry Thesis: the thesis that such virtual actions are never wrong. I also explain how the truth of the Asymmetry Thesis is closely aligned with the possibility of what Edward Castronova has called closed synthetic worlds. With some qualifications, the ultimate conclusion is that the Asymmetry Thesis is false and that these closed worlds are impossible.  相似文献   

3.
After discussing the distinction between artifacts and natural entities, and the distinction between artifacts and technology, the conditions of the traditional account of moral agency are identified. While computer system behavior meets four of the five conditions, it does not and cannot meet a key condition. Computer systems do not have mental states, and even if they could be construed as having mental states, they do not have intendings to act, which arise from an agent’s freedom. On the other hand, computer systems have intentionality, and because of this, they should not be dismissed from the realm of morality in the same way that natural objects are dismissed. Natural objects behave from necessity; computer systems and other artifacts behave from necessity after they are created and deployed, but, unlike natural objects, they are intentionally created and deployed. Failure to recognize the intentionality of computer systems and their connection to human intentionality and action hides the moral character of computer systems. Computer systems are components in human moral action. When humans act with artifacts, their actions are constituted by the intentionality and efficacy of the artifact which, in turn, has been constituted by the intentionality and efficacy of the artifact designer. All three components – artifact designer, artifact, and artifact user – are at work when there is an action and all three should be the focus of moral evaluation.  相似文献   

4.
随着计算机人机交互技术的发展,手势作为一种自然而直观的人际交流模式,手势识别也是实现新一代人机交互所不可缺少的一项关键技术。现代深度相机如Kinect、TOF等飞速发展,也促使人们对于基于深度相机的手势识别系统研究和应用的重视。文章主要介绍基于深度相机的手势识别系统方法及应用,讨论骨骼、深度图像等信息数据在识别系统中的开发和应用,最后简介深度信息的应用发展前景。  相似文献   

5.
Text-enhanced and implicit reasoning methods are proposed for answering questions over incomplete knowledge graph (KG), whereas prior studies either rely on external resources or lack necessary interpretability. This article desires to extend the line of reinforcement learning (RL) methods for better interpretability and dynamically augment original KG action space with additional actions. To this end, we propose a RL framework along with a dynamic completion mechanism, namely Dynamic Completion Reasoning Network (DCRN). DCRN consists of an action space completion module and a policy network. The action space completion module exploits three sub-modules (relation selector, relation pruner and tail entity predictor) to enrich options for decision making. The policy network calculates probability distribution over joint action space and selects promising next-step actions. Simultaneously, we employ the beam search-based action selection strategy to alleviate delayed and sparse rewards. Extensive experiments conducted on WebQSP, CWQ and MetaQA demonstrate the effectiveness of DCRN. Specifically, under 50% KG setting, the Hits@1 performance improvements of DCRN on MetaQA-1H and MetaQA-3H are 2.94% and 1.18% respectively. Moreover, under 30% and 10% KG settings, DCRN prevails over all baselines by 0.9% and 1.5% on WebQSP, indicating the robustness to sparse KGs.  相似文献   

6.
Compared to human vision, conventional machine vision composed of an image sensor and processor suffers from high latency and large power consumption due to physically separated image sensing and processing. A neuromorphic vision system with brain-inspired visual perception provides a promising solution to the problem. Here we propose and demonstrate a prototype neuromorphic vision system by networking a retinomorphic sensor with a memristive crossbar. We fabricate the retinomorphic sensor by using WSe2/h-BN/Al2O3 van der Waals heterostructures with gate-tunable photoresponses, to closely mimic the human retinal capabilities in simultaneously sensing and processing images. We then network the sensor with a large-scale Pt/Ta/HfO2/Ta one-transistor-one-resistor (1T1R) memristive crossbar, which plays a similar role to the visual cortex in the human brain. The realized neuromorphic vision system allows for fast letter recognition and object tracking, indicating the capabilities of image sensing, processing and recognition in the full analog regime. Our work suggests that such a neuromorphic vision system may open up unprecedented opportunities in future visual perception applications.  相似文献   

7.
This paper investigates a Q-learning scheme for the optimal consensus control of discrete-time multiagent systems. The Q-learning algorithm is conducted by reinforcement learning (RL) using system data instead of system dynamics information. In the multiagent systems, the agents are interacted with each other and at least one agent can communicate with the leader directly, which is described by an algebraic graph structure. The objective is to make all the agents achieve synchronization with leader and make the performance indices reach Nash equilibrium. On one hand, the solutions of the optimal consensus control for multiagent systems are acquired by solving the coupled Hamilton–Jacobi–Bellman (HJB) equation. However, it is difficult to get analytical solutions directly of the discrete-time HJB equation. On the other hand, accurate mathematical models of most systems in real world are hard to be obtained. To overcome these difficulties, Q-learning algorithm is developed using system data rather than the accurate system model. We formulate performance index and corresponding Bellman equation of each agent i. Then, the Q-function Bellman equation is acquired on the basis of Q-function. Policy iteration is adopted to calculate the optimal control iteratively, and least square (LS) method is employed to motivate the implementation process. Stability analysis of proposed Q-learning algorithm for multiagent systems by policy iteration is given. Two simulation examples are experimented to verify the effectiveness of the proposed scheme.  相似文献   

8.
Abstract

This article investigates how an account of hidden, internal properties of an everyday technology became a framework to interpret human action as a serious crime. Using a case study situated in the New York subway system, I examine the criminalization of a practice of New York’s poor known as “selling swipes” performed by so-called “swipers”. A high court came to classify the practice as felony forgery, interpreting it though an expert-witness account of how objects physically manipulated by swipers interact with a secretive, proprietary digital information system. Thousands of felony arrests – overwhelmingly of nonwhite men – have been legitimated under this theory, in which the crime occurs on a plane of technical interactions to which swipers have no access. Through close examination of the underlying technology (known as MetroCard), however, I show considerable problems in the authorities’ understanding of the technology, illustrating the hazards of interpreting human action through proprietary or complex systems, especially as they are represented solely through expert accounts. The case demonstrates fresh connections between technology and unequal outcomes in the U.S. criminal justice system, and suggests an emerging form of social vulnerability, to interpretations of our actions through the logic of technologies black-boxed to us.  相似文献   

9.
Multimodal relation extraction is a critical task in information extraction, aiming to predict the class of relations between head and tail entities from linguistic sequences and related images. However, the current works are vulnerable to less relevant visual objects detected from images and are not able to sufficiently fuse visual information into text pre-trained models. To overcome these problems, we propose a Two-Stage Visual Fusion Network (TSVFN) that employs the multimodal fusion approach in vision-enhanced entity relation extraction. In the first stage, we design multimodal graphs, whose novelty lies mainly in transforming the sequence learning into the graph learning. In the second stage, we merge the transformer-based visual representation into the text pre-trained model by a multi-scale cross-model projector. Specifically, two multimodal fusion operations are implemented inside the pre-trained model respectively. We finally accomplish deep interaction of multimodal multi-structured data in two fusion stages. Extensive experiments are conducted on a dataset (MNRE), our model outperforms the current state-of-the-art method by 1.76%, 1.52%, 1.29%, and 1.17% in terms of accuracy, precision, recall, and F1 score, respectively. Moreover, our model also achieves excellent results under the condition of fewer samples.  相似文献   

10.
Using the theory of the logarithmic potential and the methods of intersecting circles and radii, plots are obtained for the lines of flow and equipotentials for eight cases of two sources, two sinks, or a source and a sink of varying strengths. A detailed analysis of the equilibrium equipotentials is included. The problem of three unit sources placed at the vertices of an equilateral triangle is investigated; and the general expression of the equilibrium equipotential for n similar unit sources (or sinks) placed at the vertices of a regular n-sided polygon is developed.  相似文献   

11.
Humans are able to reason from multiple sources to arrive at the correct answer. In the context of Multiple Choice Question Answering (MCQA), knowledge graphs can provide subgraphs based on different combinations of questions and answers, mimicking the way humans find answers. However, current research mainly focuses on independent reasoning on a single graph for each question–answer pair, lacking the ability for joint reasoning among all answer candidates. In this paper, we propose a novel method KMSQA, which leverages multiple subgraphs from the large knowledge graph ConceptNet to model the comprehensive reasoning process. We further encode the knowledge graphs with shared Graph Neural Networks (GNNs) and perform joint reasoning across multiple subgraphs. We evaluate our model on two common datasets: CommonsenseQA (CSQA) and OpenBookQA (OBQA). Our method achieves an exact match score of 74.53% on CSQA and 71.80% on OBQA, outperforming all eight baselines.  相似文献   

12.
济南市城市森林信息提取及景观格局分析   总被引:1,自引:1,他引:0  
郑国强  赵清  朱鹏  史同广 《资源科学》2008,30(5):786-791
本文以济南市近期高分辨率遥感图像作为主要解译信息源,运用人工目视解译分类技术进行了济南市主城区城市森林景观空间分布信息的遥感调查。然后通过对城市森林蒂观类型与其空间形态特征和属性问关系的调查分析,建立了类型、属性和形态间的关系,并以此为依据,进一步进行了以几何信息为主要分类依据的城市森林景观分类的计算机自动提取,获取了济南市主城区城市森林景观类型分布图。在此基础上,选取景观多样性、破碎度和分维数等景观指数,对济南市主城区城市森林景观格局进行了定量分析。研究表明:济南市斑块单元面积大于0.5hm^2的城市森林总体覆盖率较适中,但存在严重的区域不平衡现象,城市森林景观生态特性区域差异极为明显,森林景观斑块受人类活动强烈干扰。最后,根据景观格局分析的结果,对济南市景观格局优化和城市森林建设问题提出了一些建议。  相似文献   

13.
Identifying perceived emotional content of music constitutes an important aspect of easy and efficient search, retrieval, and management of the media. One of the most promising use cases of music organization is an emotion-based playlist, where automatic music emotion recognition plays a significant role in providing emotion related information, which is otherwise, generally unavailable. Based on the importance of the auditory system in emotional recognition and processing, in this study, we propose a new cochleogram-based system for detecting the affective musical content. To effectively simulate the response of the human auditory periphery, the music audio signal is processed by a detailed biophysical cochlear model, thus obtaining an output that closely matches the characteristics of human hearing. In this proposed approach, based on the cochleogram images, which we construct directly from the response of the basilar membrane, a convolutional neural network (CNN) is used to extract the relevant music features. To validate the practical implications of the proposed approach with regard to its possible integration in different digital music libraries, an extensive study was conducted to evaluate the predictive performance of our approach in different aspects of music emotion recognition. The proposed approach was evaluated on publicly available 1000 songs database and the experimental results showed that it performed better in comparison with common musical features (such as tempo, mode, pitch, clarity, and perceptually motivated mel-frequency cepstral coefficients (MFCC)) as well as official ”MediaEval” challenge results on the same reference database. Our findings clearly show that the proposed approach can lead to better music emotion recognition performance and be used as part of a state-of-the-art music information retrieval system.  相似文献   

14.
This paper investigates the role of objects holding representations of knowledge in the transfer of learning across projects. On the basis of an in-depth case study, this paper shows that the way in which relatively simple artifacts, such as Excel workbooks, represent knowledge enables them to act as boundary objects across occupations and as memory devices across projects. It is the temporal capacity of these boundary objects that makes them points of juncture in a widely distributed memory system, enabling project-based firms to balance preservation and adaptation of knowledge. The mechanisms for the preservation of learning are not missing from project environments, rather they are less visible and less direct than in other settings, and therefore less docile in the face of managerial action.  相似文献   

15.
In the last several decades it has become an important basis to retrieve images from image databases (IDBs) by the semantic information held in the image objects and the spatial patterns formed by these objects. In this paper, we propose a new method for similarity retrieval of symbolic images by both the attributes and the spatial relationships of the contained objects. The proposed method CPM (common pattern method) retains the common spatial patterns of two images in new data structures CP_DAG (common pattern directed acyclic graph) and performs the similarity calculation efficiently in practice. The conducted experiments use both a synthetic dataset and an existing image database. The experimental results show that CPM outperforms LCS_Clique, SIMR, SIMDTC, and 2D Be-string for average efficiency and effectiveness. CPM also has steady efficiency while the number of image objects and the object symbol duplication rates increase.  相似文献   

16.
Information seeking is traditionally conducted in environments where search results are represented at the user interface by a minimal amount of meta-information such as titles and query-based summaries. The goal of this form of presentation is to give searchers sufficient context to help them make informed interaction decisions without overloading them cognitively. The principle of polyrepresentation [Ingwersen, P. (1996). Cognitive perspectives of information retrieval interaction: elements of a cognitive IR theory. Journal of Documentation 52, 3–50] suggests that information retrieval (IR) systems should provide and use different cognitive structures during acts of communication to reduce the uncertainty associated with interactive IR. In previous work we have created content-rich search interfaces that implement an aspect of polyrepresentative theory, and are capable of displaying multiple representations of the retrieved documents simultaneously at the results interface. Searcher interaction with content-rich interfaces was used as implicit relevance feedback (IRF) to construct modified queries. These interfaces have been shown to be successful in experimentation with human subjects but we do not know whether the information was presented in a way that makes good use of the display space, or positioned most useful components in easily accessible locations, for use in IRF. In this article we use simulations of searcher interaction behaviour as design tools to determine the most rational interface design for when IRF is employed. This research forms part of the iterative design of interfaces to proactively support searchers.  相似文献   

17.
In the present work we perform compressed pattern matching in binary Huffman encoded texts [Huffman, D. (1952). A method for the construction of minimum redundancy codes, Proc. of the IRE, 40, 1098–1101]. A modified Knuth–Morris–Pratt algorithm is used in order to overcome the problem of false matches, i.e., an occurrence of the encoded pattern in the encoded text that does not correspond to an occurrence of the pattern itself in the original text. We propose a bitwise KMP algorithm that can move one extra bit in the case of a mismatch since the alphabet is binary. To avoid processing any bit of the encoded text more than once, a preprocessed table is used to determine how far to back up when a mismatch is detected, and is defined so that we are always able to align the start of the encoded pattern with the start of a codeword in the encoded text. We combine our KMP algorithm with two practical Huffman decoding schemes which handle more than a single bit per machine operation; skeleton trees defined by Klein [Klein, S. T. (2000). Skeleton trees for efficient decoding of huffman encoded texts. Information Retrieval, 3, 7–23], and numerical comparisons between special canonical values and portions of a sliding window presented in Moffat and Turpin [Moffat, A., & Turpin, A. (1997). On the implementation of minimum redundancy prefix codes. IEEE Transactions on Communications, 45, 1200–1207]. Experiments show rapid search times of our algorithms compared to the “decompress then search” method, therefore, files can be kept in their compressed form, saving memory space. When compression gain is important, these algorithms are better than cgrep [Ferragina, P., Tommasi, A., & Manzini, G. (2004). C Library to search over compressed texts, http://roquefort.di.unipi.it/~ferrax/CompressedSearch], which is only slightly faster than ours.  相似文献   

18.
Trends change rapidly in today’s world, prompting this key question: What is the mechanism behind the emergence of new trends? By representing real-world dynamic systems as complex networks, the emergence of new trends can be symbolized by vertices that “shine.” That is, at a specific time interval in a network’s life, certain vertices become increasingly connected to other vertices. This process creates new high-degree vertices, i.e., network stars. Thus, to study trends, we must look at how networks evolve over time and determine how the stars behave. In our research, we constructed the largest publicly available network evolution dataset to date, which contains 38,000 real-world networks and 2.5 million graphs. Then, we performed the first precise wide-scale analysis of the evolution of networks with various scales. Three primary observations resulted: (a) links are most prevalent among vertices that join a network at a similar time; (b) the rate that new vertices join a network is a central factor in molding a network’s topology; and (c) the emergence of network stars (high-degree vertices) is correlated with fast-growing networks. We applied our learnings to develop a flexible network-generation model based on large-scale, real-world data. This model gives a better understanding of how stars rise and fall within networks, and is applicable to dynamic systems both in nature and society.Multimedia Links▶ Video ▶ Interactive Data Visualization ▶ Data ▶ Code Tutorials  相似文献   

19.
Pangolins are among the most critically endangered animals due to heavy poaching and worldwide trafficking. However, their demographic histories and the genomic consequences of their recent population declines remain unknown. We generated high-quality de novo reference genomes for critically endangered Malayan (Manis javanica, MJ) and Chinese (M. pentadactyla, MP) pangolins and re-sequencing population genomic data from 74 MJs and 23 MPs. We recovered the population identities of illegally traded pangolins and previously unrecognized genetic populations that should be protected as evolutionarily distinct conservation units. Demographic reconstruction suggested environmental changes have resulted in a population size fluctuation of pangolins. Additionally, recent population size declines due to human activities have resulted in an increase in inbreeding and genetic load. Deleterious mutations were enriched in genes related to cancer/diseases and cholesterol homeostasis, which may have increased their susceptibility to diseases and decreased their survival potential to adapt to environmental changes and high-cholesterol diets. This comprehensive study provides not only high-quality pangolin reference genomes, but also valuable information concerning the driving factors of long-term population size fluctuations and the genomic impact of recent population size declines due to human activities, which is essential for pangolin conservation management and global action planning.  相似文献   

20.
The observed properties of solar magnetic fields are reviewed, with particular reference to the complexities imposed on the field by motions of the highly conducting gas. Turbulent interactions between gas and field lead to heating or cooling of the gas according as the field energy density is less or greater than the maximum kinetic energy density in the convection zone. The field strength above which cooling sets in is 700 G.A weak solar dipole field may be primeval, but dynamo action is also important in generating new flux. The dynamo is probably not confined to the convection zone, but extends throughout most of the volume of the sun. Planetary tides appear to play a role in driving the dynamo.  相似文献   

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