检索结果-内蒙古大学图书馆

You Can Observe a Lot by Watching: Hughlings Jackson's Underappreciated and Prescient Ideas about Brain Control of Movement

引用

NEUROSCIENTIST 2018年第5期24卷 448-455页

作者： Berkowitz, Ari Univ Oklahoma Dept Biol 730 Van Vleet Oval Norman OK 73019 USA

John Hughlings Jackson, the 19th-century British neurologist, first described what are today called Jacksonian seizures. He is generally associated with somatotopy, the idea that neighboring brain regions control neighboring body parts, as later represented pictorially in Wilder Penfield's "homunculus", or little man in the brain. Jackson's own views, however, were quite different, though this is seldom appreciated. In an 1870 article, Jackson advanced the hypotheses that each region of the cerebrum controls movements of multiple body parts, but to different degrees, and that the march of movements that typically occurs during Jacksonian seizures is caused by the downstream connections of the overactive neurons at the seizure focus, rather than a somatotopic organization of the cerebrum. Jackson's hypotheses, which were based almost entirely on his careful observations of movements during seizures, are well within the range of current hypotheses about how the frontal lobe is organized to control movements and thus deserve renewed attention.

关键词： Hughlings Jackson motor cortex somatotopy homunculus distributed coding

来源：评论

学校读者我要写书评

暂无评论

Spatial precision of population activity in primate area MT

引用

JOURNAL OF NEUROPHYSIOLOGY 2015年第2期114卷 869-878页

作者： Chen, Spencer C. Morley, John W. Solomon, Samuel G. Univ Sydney Ctr Excellence Integrat Brain Funct Australian Res Council Sydney NSW 2006 Australia Univ Sydney Sch Med Sci Sydney NSW 2006 Australia Univ Western Sydney Sch Med Penrith NSW 1797 Australia UCL Inst Behav Neurosci London England

The middle temporal (MT) area is a cortical area integral to the "where" pathway of primate visual processing, signaling the movement and position of objects in the visual world. The receptive field of a single MT neuron is sensitive to the direction of object motion but is too large to signal precise spatial position. Here, we asked if the activity of MT neurons could be combined to support the high spatial precision required in the where pathway. With the use of multielectrode arrays, we recorded simultaneously neural activity at 24-65 sites in area MT of anesthetized marmoset monkeys. We found that although individual receptive fields span more than 5 degrees of the visual field, the combined population response can support fine spatial discriminations (<0.2 degrees). This is because receptive fields at neighboring sites overlapped substantially, and changes in spatial position are therefore projected onto neural activity in a large ensemble of neurons. This fine spatial discrimination is supported primarily by neurons with receptive fields flanking the target locations. Population performance is degraded (by 13-22%) when correlations in neural activity are ignored, further reflecting the contribution of population neural interactions. Our results show that population signals can provide high spatial precision despite large receptive fields, allowing area MT to represent both the motion and the position of objects in the visual world.

关键词： distributed coding marmoset multielectrode array neural correlations

来源：评论

学校读者我要写书评

暂无评论

Analog of differential-phase quantum cryptography on coherent states with provable cryptographic security

引用

JETP LETTERS 2015年第6期102卷 396-403页

作者： Molotkov, S. N. Russian Acad Sci Inst Solid State Phys Chernogolovka 142432 Moscow Region Russia Acad Cryptog Russian Federat Moscow 121552 Russia Moscow MV Lomonosov State Univ Fac Computat Math & Cybernet Moscow 119991 Russia

A quantum-cryptography protocol has been proposed by analogy with distributed coding protocols operating at sub- and gigahertz clock frequencies. In contrast to distributed coding protocols whose security has not yet ... 详细信息

关键词： Quantum cryptography ANNIHILATION OPERATORS differential phase Security distributed coding Analogy Analog

来源：评论

学校读者我要写书评

暂无评论

Asymptotic Analysis and Optimization for Generalized distributed Fountain Codes

引用

IEEE COMMUNICATIONS LETTERS 2013年第5期17卷 988-991页

作者： Shao, Hanqin Xu, Dazhuan Zhang, Xiaofei Nanjing Univ Aeronaut & Astronaut Coll Elect & Informat Engn Nanjing Peoples R China

A novel generic fountain coding scheme for multiple access networks over erasure channels is proposed and it can be applied to several instances. Moreover, asymptotic analysis using And-Or tree analysis technique is evaluated and an efficient joint optimization method employing linear and nonlinear programs is presented. Furthermore, selective distributed Luby Transform (SDLT) codes and unequal error protection (UEP) codes are evaluated as two special cases. Simulation results reveal that the proposed coding scheme can reduce decoding overhead and provide strong UEP property across sources.

关键词： Asymptotic analysis distributed coding linear program LT codes nonlinear program unequal error protection

来源：评论

学校读者我要写书评

暂无评论

Relay-Assisted Diversity Communications

引用

IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2013年第1期62卷 415-421页

作者： La Palombara, Cristina Tralli, Velio Masini, Barbara M. Conti, Andrea Univ Bologna WiLab CNR IEIIT Bologna Italy Univ Bologna DEIS Bologna Italy Univ Ferrara ENDIF I-44100 Ferrara Italy Univ Ferrara CNIT I-44100 Ferrara Italy

Relaying and diversity methods improve wireless communications by jointly exploiting the benefits of node cooperation, multiple-channel reception, and distributed processing. We develop a framework for design and analysis of relay-assisted diversity communications accounting for: 1) node positions;2) link characterization;3) diversity methods;4) distributed coding and constellation signaling;and 5) power allocation. The framework is built on a simple model for assessing the frame error probability (FEP) as a function of radio-link characteristics, and it enables a clear understanding of how the aforementioned aspects affect the performance. A novel FEP-optimal power allocation is developed and compared with other allocation techniques such as uniform, destination-balanced (D-balanced), and relay-balanced (R-balanced) power allocations. Results show the effectiveness of the novel power allocation technique for various distributed codings and provide insights into the operation of relay-assisted diversity systems.

关键词： distributed coding diversity techniques power allocation relay-assisted communications

来源：评论

学校读者我要写书评

暂无评论

A Classification of Functions in Multiterminal distributed Computing

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2020年第10期66卷 6169-6183页

作者： Watanabe, Shun Tokyo Univ Agr & Technol Dept Comp & Informat Sci Tokyo 1848588 Japan

In the distributed function computation problem, dichotomy theorems, initiated by Han-Kobayashi, seek to classify functions by whether the rate regions for function computation improve on the Slepian-Wolf regions or not. In this paper, we develop a general approach to derive converse bounds on the distributed function computation problem. By using this approach, we recover the sufficiency part, i.e. the conditions such that the Slepian-Wolf regions become optimal, of the known dichotomy theorems in the two-terminal distributed computing. Furthermore, we derive an improved sufficient condition on the dichotomy theorem in the multiterminal distributed computing for the class of i.i.d. sources with the positivity condition. Finally, we derive the matching sufficient and necessary condition on the dichotomy theorem in the multiterminal distributed computing for the class of smooth sources.

关键词： distributed computing Decoding Encoding Sensitivity Random variables Entropy distributed coding distributed computing Slepian-Wolf coding

来源：评论

学校读者我要写书评

暂无评论

Intrinsic circuitry in the deep layers of the cat superior colliculus

引用

VISUAL NEUROSCIENCE 1996年第6期13卷 1031-1042页

作者： Behan, M Kime, NM UNIV WISCONSIN CTR NEUROSCI MADISON WI USA

The mammalian superior colliculus is involved in the transformation of sensory signals into orienting behaviors. Sensory and motor signals are integrated in the colliculus to produce movements of the eyes, head, and neck. While there is a considerable amount of information available on the afferent and efferent connections of the colliculus, almost nothing is known about its intrinsic circuitry, particularly that of its deepest layers. It is likely that intrinsic connections in these deeper layers of the colliculus participate in the sensory-motor transformations leading to orienting movements. In this study, we used the neuroanatomical tracer biocytin to label small groups of neurons in the deeper layers of the cat superior colliculus and examine the distribution of their axons and terminals. We found a broadly distributed network of intrinsic projections throughout the deep layers of the superior colliculus. While the majority of terminals were found in a 1-2 mm radius around the injection site, labeled terminals were found throughout the deep layers of the colliculus up to 5 mm from the injection site. In addition, these injections sometimes labeled terminals in the superficial tectum. Extensive projections were demonstrated by the more superficial injections, but few terminals were found when injections were confined to the deepest layers of the colliculus. There was no evidence of anisotropy in the distribution of terminals from injections made at different rostrocaudal or mediolateral locations;neurons located in any one region in the colliculus could potentially influence any other region. This network of intrinsic connections in the cat superior colliculus could provide a means for deeper-layer efferent neurons to associate, and to modulate or coordinate their output. Interneurons could also provide a substrate for mutual inhibition between neurons at the rostral pole of the colliculus that are active during fixation, and more caudally located neurons whose

关键词： interneurons distributed coding biocytin eye movement fixation

来源：评论

学校读者我要写书评

暂无评论

Systematic-bit-selection distributed turbo code with selective-relaying

引用

Journal of Beijing Institute of Technology 2014年第1期23卷 73-77页

作者：侯舒娟李凌云秦学方 School of Information and Electronics Beijing Institute of Technology

An improved distributed turbo coding(DTC)scheme,namely,systematic-bit-selection DTC,is proposed for a two-hop relay network implementing selective-relaying(SR).In the scheme,source broadcasts a punctured turbo code in order to increase the successful decoding rate of *** relay forwards systematic-bit to the destination in case of successful cyclic redundancy check(CRC).From the two versions of systematic-bit coming from relay and source respectively,the destination selects the one with higher signal-to-noise ratio(SNR)for turbo *** results show the improved bit error rate(BER)performance of our scheme.

关键词： distributed coding relay network turbo coding selective-relaying

来源：评论

学校读者我要写书评

暂无评论

PROPERTIES OF NUMERIC CODES FOR THE SCHEME OF RANDOM SUBSPACES RSC

引用

CYBERNETICS AND SYSTEMS ANALYSIS 2005年第4期41卷 509-520页

作者： Rachkovskii, D. A. Slipchenko, S. V. Kussul, E. M. Baidyk, T. N. Int Sci Educ Ctr Informat Technol & Syst Kiev Ukraine Univ Nacl Autonoma Mexico Mexico City Mexico

Properties of coarse coding obtained by using the random subspace coding (RSC) scheme with random hyperrectangular receptive fields are considered. Characteristics of codes are provided such as the dimensionality of receptive fields, code density at various points of the input space, code overlapping, and others. The results of theoretical analysis are illustrated by experiments with high-dimensional codes.

关键词： coarse coding receptive fields distributed coding neural network hyperrectangle CMAC RSC

来源：评论

学校读者我要写书评

暂无评论

EXIT Analysis for MAP-Based Joint Iterative Decoding of Separately Encoded Correlated Sources

引用

IEICE TRANSACTIONS ON COMMUNICATIONS 2010年第12期E93B卷 3509-3513页

作者： Kobayashi, Kentaro Yamazato, Takaya Katayama, Masaaki Nagoya Univ EcoTopia Sci Inst Nagoya Aichi 4648603 Japan Nagoya Univ Inst Liberal Arts & Sci Nagoya Aichi 4648603 Japan

We develop a mathematical framework for the extrinsic information transfer (EXIT) analysis to assess the convergence behavior of maximum a posteriori (MAP) based joint iterative decoding of correlated sources which are separately encoded and transmitted over noisy channels Unlike the previous work our approach focuses on the case side information about the correlation is not perfectly given at the joint decoder but is extracted from decoder output and updated in an iterative manner The presented framework provides a convenient way to compare between schemes We show that it allows us to easily and accurately predict Joint decoding gain and turbo cliff position

关键词： EXIT analysis correlated sources joint decoding iterative decoding distributed coding

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：