期刊文献+
共找到8,326篇文章
< 1 2 250 >
每页显示 20 50 100
Abstraction and Representation:Form and Meaning in the Philosophy of Images
1
作者 YUAN Zhen-wei 《Journal of Literature and Art Studies》 2023年第9期716-720,共5页
This article examines the complex interplay between abstraction and representation in the ontology of images.Images inhabit an in-between space as tangible artifacts that also convey intangible ideas and meanings.The ... This article examines the complex interplay between abstraction and representation in the ontology of images.Images inhabit an in-between space as tangible artifacts that also convey intangible ideas and meanings.The analysis synthesizes perspectives from across the history of philosophy to elucidate how images bridge abstraction and representation through their form and function.It engages with ongoing epistemological and aesthetic debates concerning the dual nature of images.Plato’s theory of ideal forms is outlined as an early attempt to define abstraction.Modern semiotic theories are discussed for their insights into how images create meaning through codes and signs.Phenomenology offers an alternative approach by prioritizing the sensorial,affective impact of images.Poststructuralism problematizes representation in the context of mechanical reproduction and simulacra.While diverse,these philosophical frameworks all grapple with the issues images pose between abstract essence and concrete appearance,conceptual ideas and sensory manifestations.The article reveals the richness of images as liminal constructs that collapse dualisms in their creative interfacing of material forms and immaterial meanings.It concludes that this ontological ambiguity empowers images as mediators between imagination and perception,subjectivity and reality. 展开更多
关键词 abstraction IMAGES SEMIOTICS DUALISM PLATO
下载PDF
A Comparative Analysis of Syntactic Complexity in Applied Linguistics Abstracts Written by Chinese Novice Writers and Native English Advanced Writers
2
作者 Mingming Zhao Tianshuang Ge 《Open Journal of Applied Sciences》 2024年第1期1-26,共26页
The rhetorical structure of abstracts has been a widely discussed topic, as it can greatly enhance the abstract writing skills of second-language writers. This study aims to provide guidance on the syntactic features ... The rhetorical structure of abstracts has been a widely discussed topic, as it can greatly enhance the abstract writing skills of second-language writers. This study aims to provide guidance on the syntactic features that L2 learners can employ, as well as suggest which features they should focus on in English academic writing. To achieve this, all samples were analyzed for rhetorical moves using Hyland’s five-rhetorical move model. Additionally, all sentences were evaluated for syntactic complexity, considering measures such as global, clausal and phrasal complexity. The findings reveal that expert writers exhibit a more balanced use of syntactic complexity across moves, effectively fulfilling the rhetorical objectives of abstracts. On the other hand, MA students tend to rely excessively on embedded structures and dependent clauses in an attempt to increase complexity. The implications of these findings for academic writing research, pedagogy, and assessment are thoroughly discussed. 展开更多
关键词 Syntactic Complexity Rhetorical Functions Research Article abstract L2 Academic Writing
下载PDF
Theoretical Study on the Excited-state Intramolecular Hydrogen Abstraction Reactions of Butanal 被引量:1
3
作者 吕玲玲 杨声 +2 位作者 袁琨 王小芳 王永成 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2009年第10期1226-1235,共10页
The excited-state intramolecular hydrogen abstraction reactions of butanal have been investigated using the CAS-MP2/6-311+G^*//CASSCF/6-31G^* methods. Calculated results show that the hydrogen transfer induced fluo... The excited-state intramolecular hydrogen abstraction reactions of butanal have been investigated using the CAS-MP2/6-311+G^*//CASSCF/6-31G^* methods. Calculated results show that the hydrogen transfer induced fluorescence quenching of the n,π^*-excited state of covalent butanal with three paths: (1) The first path corresponds to direct S0-react reconstitution, which involves the first S1 decay by partial hydrogen atom transfer. (2) The second stepwise mechanism can be viewed as a full hydrogen atom transfer followed by a partial hydrogen atom back transfer, electron transfer (near S1/S0 or S0-TS) and finally a proton transfer to S0-react. (3) On the triplet surface, the surface crossing to the singlet state would be clearly much efficient at the T1/S0 region due to the large SOC value of 8.3 cm^-1. The S0-react decay route from T1/S0 was studied with an intrinsic reaction coordinate (IRC) calculation at the CASSCF level, resulting in the S0-React minimum. 展开更多
关键词 butanal valence bond theory (VB) state correlation diagram hydrogen abstraction mechanism
下载PDF
Topology Abstraction Service for IP VPNs: Core Network Partitioning for Resource Sharing 被引量:1
4
作者 Ravishankar Ravindran Changcheng Huang +1 位作者 Krishnaiyan Thulasiraman Tachun Lin 《American Journal of Operations Research》 2018年第3期167-202,共36页
VPN service providers (VSP) and IP-VPN customers have traditionally maintained service demarcation boundaries between their routing and signaling entities. This has resulted in the VPNs viewing the VSP network as an o... VPN service providers (VSP) and IP-VPN customers have traditionally maintained service demarcation boundaries between their routing and signaling entities. This has resulted in the VPNs viewing the VSP network as an opaque entity and therefore limiting any meaningful interaction between the VSP and the VPNs. A key challenge is to expose each VPN to information about available network resources through an abstraction (TA) [1] which is both accurate and fair. In [2] we proposed three decentralized schemes assuming that all the border nodes performing the abstraction have access to the entire core network topology. This assumption likely leads to over- or under-subscription. In this paper we develop centralized schemes to partition the core network capacities, and assign each partition to a specific VPN for applying the decentralized abstraction schemes presented in [2]. First, we present two schemes based on the maximum concurrent flow and the maximum multicommodity flow (MMCF) formulations. We then propose approaches to address the fairness concerns that arise when MMCF formulation is used. We present results based on extensive simulations on several topologies, and provide a comparative evaluation of the different schemes in terms of abstraction efficiency, fairness to VPNs and call performance characteristics achieved. 展开更多
关键词 IP-VPN SERVICE TOPOLOGY abstraction MAXIMUM Concurrent FLOW MAXIMUM MULTICOMMODITY FLOW
下载PDF
Automatic abstraction of interference fringes with image technique
5
作者 浦昭邦 陶卫 张敏 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2002年第2期166-169,共4页
ion technique of interference fringes used in phase modulation and phase scanning modulation interferometer is presented. For the measurement of amplitudes of interference fringes, fringes are fitted and their central... ion technique of interference fringes used in phase modulation and phase scanning modulation interferometer is presented. For the measurement of amplitudes of interference fringes, fringes are fitted and their central points are determined automatically according to their distribution rules. However, for the measurement of their phases, fringes should be recognized and processed with different calculating algorithms and least square optimization methods depending on the scanning modulation mode. When this technique is used for measurement of surface roughness, the measurement uncertainty is better than 5nm and the repeatability is less than 5%. 展开更多
关键词 INTERFERENCE FRINGES abstraction PHASE-MODULATION IMAGE detection
下载PDF
Abstraction from Constructors and Functional Constructors and Their Applications
6
作者 Kazuhiko Kakehi 1, Robert Gluck 2, Yoshihiko Futamura 3 1 JSPS Research Fellow Graduate School of Science and Engineering, Waseda University,Tokyo 169 8555, Japan 2 PRESTO, JST & Institute for Software Production Technology, Waseda Universi 《Wuhan University Journal of Natural Sciences》 CAS 2001年第Z1期368-374,共7页
Structures using constructors are of ordinary use in functional programming to represent data structures of unbound size. Lack of associativity of constructors, however, hinders program analyses or efficient execution... Structures using constructors are of ordinary use in functional programming to represent data structures of unbound size. Lack of associativity of constructors, however, hinders program analyses or efficient executions. This paper describes ideas of abstraction toward constructors, and similarly abstraction from constructing functions, which we call functional constructors. We demonstrate our ideas making program analyses easier and enable transformation to efficient execution. 展开更多
关键词 program transformation lambda abstraction CONSTRUCTORS recursion removal tupling
下载PDF
The CH_3OH+Cl Hydrogen Abstraction Reactions: An ab initio Study
7
作者 Bo Zhen CHEN Ming Bao HUANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2001年第8期727-730,共4页
The two channels of the CH(3)OH+Cl hydrogen abstraction reaction, leading to the final products CH(2)OH+HCl (i) and CH(3)O+HCl (ii), have been studied by performing ab initio MP2 calculations with the triplet split-va... The two channels of the CH(3)OH+Cl hydrogen abstraction reaction, leading to the final products CH(2)OH+HCl (i) and CH(3)O+HCl (ii), have been studied by performing ab initio MP2 calculations with the triplet split-valence polarization basis sets. For each of the two channels the following simple reaction path is predicted: reactants --> transition state --> intermediate --> products. The previously reported complicated paths(2) calculated without using the IRC technique are criticized. Our calculations indicate that channel (i) is exothermic and has a negligible energy barrier while channel (ii) is endothermic and has a substantial energy barrier. These results imply that channel (i) is favorable, which is in line with experiment. 展开更多
关键词 abstraction reaction ab initio calculation IRC
下载PDF
Vibration Feature Abstraction and Classification of Diesel Fault 被引量:1
8
作者 ZHANG Xi ning, WEN Guang rui, LI Xin yi College of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049, P.R.China Abstract: The feature of a periodic cyclic nonstationary signal for a cyclic working machine such as a diesel engine is studied in the aspect of working procedure, force and vibration. On the basis of the study, a method of characteristic 《International Journal of Plant Engineering and Management》 2003年第1期35-40,共6页
ion and classification is put forward for periodic cyclic nonstationary vibration signal. The proposed method is applied to experimental data of an ISUZU C240 diesel engine. Experiment results show the effectiveness ... ion and classification is put forward for periodic cyclic nonstationary vibration signal. The proposed method is applied to experimental data of an ISUZU C240 diesel engine. Experiment results show the effectiveness of the proposed method in classification of engine faults. 展开更多
关键词 diesel engine periodic cyclic nonstationary signal feature abstraction principal component analysis
下载PDF
Deadlock detection using abstraction refinement
9
作者 曾红卫 《Journal of Shanghai University(English Edition)》 2010年第1期1-5,共5页
This paper adopts counterexample guided abstraction refinement scheme to alleviate the state explosion problem of deadlock detection. We extend the classical labeled transition system models by qualifying transitions ... This paper adopts counterexample guided abstraction refinement scheme to alleviate the state explosion problem of deadlock detection. We extend the classical labeled transition system models by qualifying transitions as certain and uncertain to make deadlock-freedom conservative, i.e. if the abstraction of a system is deadlock-free, then the system is deadlock-free. An abstraction refinement approach to deadlock detection is proposed, and the correctness of the approach is proved. 展开更多
关键词 deadlock detection state explosion extended labeled transition system abstraction refinement COUNTEREXAMPLE
下载PDF
Modeling Abstraction Hierarchy Levels of the Cyber Attacks Using Random Process
10
作者 Gilles Durrieu Emmanuel Frenod +1 位作者 Thierry Morineau Thong Quoc Nguyen 《Open Journal of Statistics》 2017年第3期500-520,共21页
Aspects of human behavior in cyber security allow more natural security to the user. This research focuses the appearance of anticipating cyber threats and their abstraction hierarchy levels on the mental picture leve... Aspects of human behavior in cyber security allow more natural security to the user. This research focuses the appearance of anticipating cyber threats and their abstraction hierarchy levels on the mental picture levels of human. The study concerns the modeling of the behaviors of mental states of an individual under cyber attacks. The mental state of agents being not observable, we propose a non-stationary hidden Markov chain approach to model the agent mental behaviors. A renewal process based on a nonparametric estimation is also considered to investigate the spending time in a given mental state. In these approaches, the effects of the complexity of the cyber attacks are taken into account in the models. 展开更多
关键词 CYBER ATTACKS abstraction HIERARCHY Hidden Markov Chain NONPARAMETRIC Estimation RENEWAL Process
下载PDF
Density Functional Theory Studies on the Addition and Abstraction Reactions of OH Radical with Benzoate Anion
11
作者 Nobuaki Tanaka Shigeo Itoh 《Open Journal of Physical Chemistry》 2013年第1期7-13,共7页
The addition and abstraction reactions of OH radical with benzoate anion are investigated by density functional theory calculations that include solvent effects using UB3LYP, UCAM-B3LYP, UmPW1PW91 and UM06-2X function... The addition and abstraction reactions of OH radical with benzoate anion are investigated by density functional theory calculations that include solvent effects using UB3LYP, UCAM-B3LYP, UmPW1PW91 and UM06-2X functionals with the 6-311++G(2d,2p) basis set. Geometry optimizations of the reactants, products and transition state species are performed for the possible reaction paths. For the addition reactions, those targeting the ipso-, ortho-, meta- and para-carbons are predicted to be exoergic. The H-atom abstraction reactions from ortho, meta and para positions are also predicted to be exoergic. On the basis of the rate constants calculated by means of the transition state theory, the H-atom abstraction reaction from the ortho position is determined to be the favored path followed by the ortho OH addition reaction. 展开更多
关键词 DFT Calculation BENZOATE ANION H-ATOM abstraction OH ADDITION Transition State Theory
下载PDF
Real-time flow-based video abstraction using OpenCL
12
作者 Yong-jin PARK Jin-woo KIM +1 位作者 Jin-hong PARK Tack-don HAN 《Journal of Measurement Science and Instrumentation》 CAS 2012年第1期46-50,共5页
A non-photorealistic rendering technique is a method to show various effects different from those of realistic image generation.Of the various techniques,flow-based image abstraction displays the shape and color featu... A non-photorealistic rendering technique is a method to show various effects different from those of realistic image generation.Of the various techniques,flow-based image abstraction displays the shape and color features well and performs a stylistic visual abstraction.But real-time rendering is impossible when CPU is used because it applies various filtering and iteration methods.In this paper,we present real-time processing methods of video abstraction using open open computing language(OpenCL),technique of general-purpose computing on graphics processing units(GPGPU).Through the acceleration of general-purpose computing(GPU),16 frame-per-second(FPS)or greater is shown to process video abstraction. 展开更多
关键词 non-photorealistic rendering video abstraction general-purpose computing on graphics processing units(GPGPU) open computing language(OpenCL)
下载PDF
Multiple Levels of Abstraction in the Simulation of Microthreaded Many-Core Architectures
13
作者 Irfan Uddin 《Open Journal of Modelling and Simulation》 2015年第4期159-190,共32页
Simulators are generally used during the design of computer architectures. Typically, different simulators with different levels of complexity, speed and accuracy are used. However, for early design space exploration,... Simulators are generally used during the design of computer architectures. Typically, different simulators with different levels of complexity, speed and accuracy are used. However, for early design space exploration, simulators with less complexity, high simulation speed and reasonable accuracy are desired. It is also required that these simulators have a short development time and that changes in the design require less effort in the implementation in order to perform experiments and see the effects of changes in the design. These simulators are termed high-level simulators in the context of computer architecture. In this paper, we present multiple levels of abstractions in a high-level simulation of a general-purpose many-core system, where the objective of every level is to improve the accuracy in simulation without significantly affecting the complexity and simulation speed. 展开更多
关键词 HIGH-LEVEL Simulations MULTIPLE LEVELS of abstraction Design Space Exploration MANY-CORE Systems
下载PDF
Internal Water Flows and Particles Abstraction in Daphnia
14
作者 Moshe Gophen 《Open Journal of Ecology》 2022年第11期742-755,共14页
The operational function of the trunk limbs (thoracic appendages), of Daphnia, P3 and P4, is a long-term disputed definition between “solid walls”, sieving filters. Sieving is unlikely process for routine particle c... The operational function of the trunk limbs (thoracic appendages), of Daphnia, P3 and P4, is a long-term disputed definition between “solid walls”, sieving filters. Sieving is unlikely process for routine particle collection, particle capture is not a simple mechanical process and not by sieving alone. Analysis promotion supported by direct observational examination of the in-vivo cinematographic slow-motion film and magnified solid photos of tethered Daphnia by high-speed camera (250 frames per second) resulted in a definite interpretation presented in this paper. The Daphnia’s feeding mechanism achieves particles abstraction not by sieving. The existence of two internal alternate water flow routs was indicated: Lateral and Median. These micro flow structures are suggested as vulnerability reduction. 展开更多
关键词 DAPHNIA Particle abstraction Solid Walls Internal Flow Rout
下载PDF
Research on the Automatic Pattem Abstraction and Recognition Methodology for Large-scale Database System based on Natural Language Processing 被引量:1
15
作者 RongWang Cuizhen Jiao Wenhua Dai 《International Journal of Technology Management》 2015年第9期125-127,共3页
关键词 大型数据库系统 自然语言处理 识别方法 模式提取 自动模式 分布式数据库 数据库设计 网络连接
下载PDF
Weakly Supervised Abstractive Summarization with Enhancing Factual Consistency for Chinese Complaint Reports
16
作者 Ren Tao Chen Shuang 《Computers, Materials & Continua》 SCIE EI 2023年第6期6201-6217,共17页
A large variety of complaint reports reflect subjective information expressed by citizens.A key challenge of text summarization for complaint reports is to ensure the factual consistency of generated summary.Therefore... A large variety of complaint reports reflect subjective information expressed by citizens.A key challenge of text summarization for complaint reports is to ensure the factual consistency of generated summary.Therefore,in this paper,a simple and weakly supervised framework considering factual consistency is proposed to generate a summary of city-based complaint reports without pre-labeled sentences/words.Furthermore,it considers the importance of entity in complaint reports to ensure factual consistency of summary.Experimental results on the customer review datasets(Yelp and Amazon)and complaint report dataset(complaint reports of Shenyang in China)show that the proposed framework outperforms state-of-the-art approaches in ROUGE scores and human evaluation.It unveils the effectiveness of our approach to helping in dealing with complaint reports. 展开更多
关键词 Automatic summarization abstractive summarization weakly supervised training entity recognition
下载PDF
Novel multi‐domain attention for abstractive summarisation
17
作者 Chunxia Qu Ling Lu +2 位作者 Aijuan Wang Wu Yang Yinong Chen 《CAAI Transactions on Intelligence Technology》 SCIE EI 2023年第3期796-806,共11页
The existing abstractive text summarisation models only consider the word sequence correlations between the source document and the reference summary,and the summary generated by models lacks the cover of the subject ... The existing abstractive text summarisation models only consider the word sequence correlations between the source document and the reference summary,and the summary generated by models lacks the cover of the subject of source document due to models'small perspective.In order to make up these disadvantages,a multi‐domain attention pointer(MDA‐Pointer)abstractive summarisation model is proposed in this work.First,the model uses bidirectional long short‐term memory to encode,respectively,the word and sentence sequence of source document for obtaining the semantic representations at word and sentence level.Furthermore,the multi‐domain attention mechanism between the semantic representations and the summary word is established,and the proposed model can generate summary words under the proposed attention mechanism based on the words and sen-tences.Then,the words are extracted from the vocabulary or the original word sequences through the pointer network to form the summary,and the coverage mechanism is introduced,respectively,into word and sentence level to reduce the redundancy of sum-mary content.Finally,experiment validation is conducted on CNN/Daily Mail dataset.ROUGE evaluation indexes of the model without and with the coverage mechanism are improved respectively,and the results verify the validation of model proposed by this paper. 展开更多
关键词 abstractive summarisation attention mechanism Bi‐LSTM coverage mechanism pointer network
下载PDF
A Method of Integrating Length Constraints into Encoder-Decoder Transformer for Abstractive Text Summarization
18
作者 Ngoc-Khuong Nguyen Dac-Nhuong Le +1 位作者 Viet-Ha Nguyen Anh-Cuong Le 《Intelligent Automation & Soft Computing》 2023年第10期1-18,共18页
Text summarization aims to generate a concise version of the original text.The longer the summary text is,themore detailed it will be fromthe original text,and this depends on the intended use.Therefore,the problem of... Text summarization aims to generate a concise version of the original text.The longer the summary text is,themore detailed it will be fromthe original text,and this depends on the intended use.Therefore,the problem of generating summary texts with desired lengths is a vital task to put the research into practice.To solve this problem,in this paper,we propose a new method to integrate the desired length of the summarized text into the encoder-decoder model for the abstractive text summarization problem.This length parameter is integrated into the encoding phase at each self-attention step and the decoding process by preserving the remaining length for calculating headattention in the generation process and using it as length embeddings added to theword embeddings.We conducted experiments for the proposed model on the two data sets,Cable News Network(CNN)Daily and NEWSROOM,with different desired output lengths.The obtained results show the proposed model’s effectiveness compared with related studies. 展开更多
关键词 Length controllable abstractive text summarization length embedding
下载PDF
Analysis of Common Mistakes in English Abstract Writing of Scientific and Technological Papers:A Case Study of Automotive Practical Technology
19
作者 Wenjuan Huang Yuansheng Zhou 《Journal of Contemporary Educational Research》 2023年第10期52-58,共7页
Abstract is the epitome of the core idea of a journal paper.Excellent English abstract plays an important role in ensuring the quality of the paper and promoting its academic value in international exchanges.However,t... Abstract is the epitome of the core idea of a journal paper.Excellent English abstract plays an important role in ensuring the quality of the paper and promoting its academic value in international exchanges.However,there are still many problems in the English abstracts of many papers published in academic journals.This paper analyzes and summarizes the grammatical errors of articles,singular and plural nouns,predicate verbs,conjunctions,Chinglish from other English abstracts of some papers in a vehicle engineering academic journal retrieved from CNCN.cn,and then corrects them.It is expected to provide some guidance for editors,academic workers,and engineering students in writing papers. 展开更多
关键词 Scientific and technological papers English abstract GRAMMAR
下载PDF
数学教学视域下理解与应用皮亚杰建构主义理论
20
作者 张涛 代钦 李春兰 《数学教育学报》 北大核心 2024年第3期96-102,共7页
建构主义是皮亚杰发生认识论的核心,同时也是现代建构主义教学的主要理论基础,对建构主义教学思想的发展和国际教育改革均产生了重要影响.其理论从心理学的角度阐述了有变化的“重复”能够促进认知的发展,能够有效地促进学生的数学学习... 建构主义是皮亚杰发生认识论的核心,同时也是现代建构主义教学的主要理论基础,对建构主义教学思想的发展和国际教育改革均产生了重要影响.其理论从心理学的角度阐述了有变化的“重复”能够促进认知的发展,能够有效地促进学生的数学学习.在阐述平衡机制、反省抽象等相关内容的基础上,研究得出反省抽象范畴之间的关系框架图、在数学教学中的应用路径,以及皮亚杰建构主义理论对当下数学教学的启示:数学教学应关注过程教育、数学教学过程中应把经验抽象与反省抽象有机结合、数学抽象思维教学应遵循思维发展的阶段性、数学教学应重视学生批判性思维能力的培养. 展开更多
关键词 皮亚杰 建构主义 发生认识论 反省抽象 数学教学
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部