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81.
Multi-stage molding is capable of producing better-quality articulated products at a lower cost. During the multi-stage molding process, assembly operations are performed along with the molding operations. Hence, it gives rise to a new type of planning problem. It is difficult to perform the planning manually because it involves evaluating large number of combinations and solving complex geometric reasoning problems. This paper investigates the problem of generating multi-stage molding plans for articulated assemblies. We present a planning framework that allows us to utilize constraints from experimentally proven molding plans. As a part of the planning problem, we determine the molding sequence and intermediate assembly configurations. We present algorithms for all the steps in the planning problem and characterize their computational complexities. Finally, we illustrate our approach with representative examples. 相似文献
82.
83.
In this paper we consider uncountable classes recognizable by ω-automata and investigate suitable learning paradigms for them. In particular, the counterparts of explanatory, vacillatory and behaviourally correct learning are introduced for this setting. Here the learner reads in parallel the data of a text for a language L from the class plus an ω-index α and outputs a sequence of ω-automata such that all but finitely many of these ω-automata accept the index α if and only if α is an index for L.It is shown that any class is behaviourally correct learnable if and only if it satisfies Angluin’s tell-tale condition. For explanatory learning, such a result needs that a suitable indexing of the class is chosen. On the one hand, every class satisfying Angluin’s tell-tale condition is vacillatorily learnable in every indexing; on the other hand, there is a fixed class such that the level of the class in the hierarchy of vacillatory learning depends on the indexing of the class chosen.We also consider a notion of blind learning. On the one hand, a class is blind explanatorily (vacillatorily) learnable if and only if it satisfies Angluin’s tell-tale condition and is countable; on the other hand, for behaviourally correct learning, there is no difference between the blind and non-blind version.This work establishes a bridge between the theory of ω-automata and inductive inference (learning theory). 相似文献
84.
Emergent semantics through interaction in image databases 总被引:9,自引:0,他引:9
Santini S. Gupta A. Jain R. 《Knowledge and Data Engineering, IEEE Transactions on》2001,13(3):337-351
In this paper, we briefly discuss some aspects of image semantics and the role that it plays for the design of image databases. We argue that images don't have an intrinsic meaning, but that they are endowed with a meaning by placing them in the context of other images and by the user interaction. From this observation, we conclude that, in an image, database users should be allowed to manipulate not only the individual images, but also the relation between them. We present an interface model based on the manipulation of configurations of images 相似文献
85.
Ansari N. Sakarindr P. Haghani E. Chao Zhang Jain A.K. Shi Y.Q. 《Security & Privacy, IEEE》2008,6(3):30-39
Despite their widespread deployment, questions about electronic voting systems' performance emerge following many elections. To encourage full public confidence in the electoral process, some researchers recommend equipping electronic voting machines with voter-verifiable audit trails that print out paper records that voters can read and verify. In this article, the authors report on their analysis and testing of one US state's criteria for direct-recording electronic (DRE) voting machines equipped with voter-verified paper-record (VVPR) systems. The criteria and analysis cover various categories, including privacy, security, verification, integrity, functionality, and examination. The authors describe their testing methodologies, discuss issues exhibited by different voting systems, and propose solutions to address those issues. 相似文献
86.
Chakrabarti A Naik V Dechoudhury S Bandyopadhyay A Mondal M Pandey HK Roy TK Sanyal D Bhowmick D 《The Review of scientific instruments》2007,78(4):043303
A 33.7 MHz heavy-ion radio frequency quadrupole (RFQ) linear accelerator has been designed, built, and tested. It is a four-rod-type RFQ designed for acceleration of 1.38 keVu, qA> or =116 ions to about 29 keVu. Transmission efficiencies of about 85% and 80% have been measured for the unanalyzed and analyzed beams, respectively, of oxygen ((16)O(2+), (16)O(3+), (16)O(4+)), nitrogen ((14)N(3+), (14)N(4+)), and argon ((40)Ar(4+)). The system design and measurements along with results of beam acceleration test will be presented. 相似文献
87.
88.
Gediminas Adomavicius Jesse C. Bockstedt Alok Gupta Robert J. Kauffman 《Information Technology and Management》2007,8(2):185-202
We propose a new conceptual model for understanding technology evolution that highlights dynamic and highly interdependent
relationships among multiple technologies. We argue that, instead of considering technologies in isolation, technology evolution
is best viewed as a dynamic system or ecosystem that includes a variety of interrelated technologies. By considering the interdependent nature of technology evolution, we
identify three roles that technologies play within a technology ecosystem. These roles are components, products and applications, and support and infrastructure. Technologies within an ecosystem interact through these roles and impact each others’ evolution. We also classify types
of interactions between technology roles, which we term paths of influence. We demonstrate the use of our proposed model through examples of wireless networking (Wi-Fi) technologies and a business
mini-case on the digital music industry.
相似文献
Robert J. KauffmanEmail: |
89.
The frequent difficulties encountered in the diagnosis of pediatric sarcomas, caused by the lack of observable differentiation at the light microscopic level, has led to the routine use of immunohistochemistry in pediatric surgical pathology. To a large degree the advent of this staining technique has led to the correct assessment of many perplexing lesions that previously would have been given inconclusive diagnoses. However, with increased usage and testing, it has become apparent that there are few, if any, "magic bullets" in immunohistochemistry for pediatric pathologists. Thus, it behooves diagnosticians to be careful in the usage of this technique, to be aware of possible discrepancies in its results, and to remember the ancillary nature of its application. The following article will review selected markers commonly used in pediatric surgical pathology, from both previous reports and the author's perspective, and will briefly consider several new phenotypic markers which have potential utility with childhood sarcomas. 相似文献
90.
In this paper we explore and analyze the structure of Internet auctions from an analytical and an empirical perspective. Such
web‐based auctions are rapidly emerging as a mercantile process of choice in the electronic marketplace. We observe current
Internet auctions for one‐time products, such as rapidly aging hardware, and analyze them within the framework of the existing
auction theory. While traditional auction theory focuses on single‐item auctions, we observe that a majority of on‐line auctions
are multi‐item auctions. A significant contribution of this work is the theoretical derivation of the structure of the winning
bids in multi‐item progressive on‐line auctions. Additionally, for comparative purposes, we explore the structural characteristics
of alternative multi‐item auction mechanisms proposed in the auction theory. We derive hypotheses based on our analytical
results and compare two different types of auction mechanisms. We test the traditional auction theory assumption regarding
the homogeneity of bidders and present the first ever empirically derived classification and performance‐comparison of on‐line
bidders. We test our hypotheses using real‐world empirical data obtained by tracking a premier web‐based auction site. Statistical
analysis of the data indicates that firms may gain by choosing alternative auction mechanisms. We also provide directions
for further exploration of this emerging but important dimension of electronic commerce.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献