作者：
MORIMOTO, KIRIGUCHI, HAOE, JMemberFaculty of Engineering
Tokushima University Tokushima Japan 770 Jun-ichi Aoe received his B.E. and M.E. degrees in 1974 and 1976
respectively from Tokushima Univ. where he was a Research Associate in the Dept. Inf. Fac. Eng. received his Ph.D. later. Presently Prof. Intel. Inf. He is engaged in research on compiler generation system and highly efficient pattern matching algorithm. Presently interestedin natural language processing especially understanding system. He is the author of “Computer Algorithms- Key Search Strategies” IEEE CS Press. Best Author Award 1992 Inf. Proc. Soc. Member Inf. Proc. Soc. Jap. Soc. Artif. Intel. Jap. Software Sci. Jap. Jap. Soc. Mach. Transl. IEEE ACM and AAAI.
The trie has the feature that the retrieval can be executed with the character symbols composing the key as the unit, and a high-speed retrieval is realized independently of the total number of keys. Consequently, it ...
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The trie has the feature that the retrieval can be executed with the character symbols composing the key as the unit, and a high-speed retrieval is realized independently of the total number of keys. Consequently, it used frequently in the search of the natural language dictionary and in other problems. A problem, however, is that the number of trie states increases with the enlargement of the key set, which necessitates a larger memory capacity. To remedy this point, DAWG (Directed Acyclic Word-Graph) is proposed, where the common suffix of the tries is compressed. Then, a new problem arises in that the record information cannot be determined uniquely for the key. For this problem, this paper introduces a new structure, where the number of states is reduced by merging the common suffixes of the tries, while determining uniquely the record information for the key. The algorithm for retrieval, insertion and deletion of the key is proposed for the structure. In the proposed method, the set of keys is represented using two tries. One of the tries memorizes the prefix of the minimum length that can discriminate uniquely between the key from other keys. The other trie stores the suffixes of the remaining keys in order to merge the common suffix. A simulation is executed for various sets of keys such as Chinese character called Kanji, alphabets and Japanese Katakana characters, and it is seen that the number of states is reduced by approximately 30 to 65 percent for the key set of 50,000 words, compared to the ordinary trie.
For maintainers involved in understanding and reengineering large software. locating source code fragments that match certain patterns is a critical task. Existing solutions to the problem are few, and they either inv...
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For maintainers involved in understanding and reengineering large software. locating source code fragments that match certain patterns is a critical task. Existing solutions to the problem are few, and they either involve manual, painstaking scans of the source code using tools based on regular expressions, or the use of large, integrated softwareengineering environments that include simple pattern-based query processors in their tool-kits. We present a framework in which pattern languages are used to specify interesting code features. The pattern languages are derived by extending the source programming language with pattern-matching symbols. We describe SCRUPLE, a finite state machine-based source code search tool, that efficiently implements this framework. We also present experimental performance results obtained from a SCRUPLE prototype, and the user interface of a source code browser built on top of SCRUPLE.
Students of softwareengineering very rarely have the opportunity to gather experience in leading projects. This not only restricts their management skills, but also prevents them from learning about the project mana...
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Object-Z is an extension of the formal specification language Z, augmenting the class concept as a structuring facility. The paper introduces and discusses a structural mapping system from Object-Z to the programming ...
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In this paper, we give an efficient algorithm, the SAT1.2 algorithm, for the SAT problem. For randomly generated formulas with n clauses, m variables, and l literals per clause, the average run time of the SAT1.2 algo...
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A novel family of six-port reflectometers, designed in hybrid stripline-waveguide technology, is proposed for high power applications. In principle, there is no limitation in the input power level and the design can b...
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A novel family of six-port reflectometers, designed in hybrid stripline-waveguide technology, is proposed for high power applications. In principle, there is no limitation in the input power level and the design can be adapted for any waveguide frequency band. A prototype was designed for the operational frequency of 2.45 GHz and measurements were made at power level up to 200 W.< >
An active integrated antenna may be defined as a radiating element on which the current distribution along the structure may be altered in a controlled manner. The ability to control the current distribution along its...
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A generalized calibration and de-embedding technique for reflection-based S-parameter measurements of microwave devices is proposed. This technique allows to perform the two-port calibration of a network analyzer dire...
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A generalized calibration and de-embedding technique for reflection-based S-parameter measurements of microwave devices is proposed. This technique allows to perform the two-port calibration of a network analyzer directly from the embedded reflection coefficient measurements. This technique is a general one, in the sense that it can be implemented in network analyzers with or without transmission measurement capabilities.< >
A systematic scaling approach for the modeling of high-power/large-size HBTs is presented. The measured S-parameters of a three elementary-cell HBT are compared to those obtained with the scaled model and the commonly...
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A systematic scaling approach for the modeling of high-power/large-size HBTs is presented. The measured S-parameters of a three elementary-cell HBT are compared to those obtained with the scaled model and the commonly used lumped equivalent circuit model. It is shown that a better fit to the measured S parameters is obtained when the scaled model is used. The interconnections and parasitics between elementary cells are accounted for based on the actual footprint of the device.< >
An active integrated antenna may be defined as a radiating element on which the current distribution along the structure may be altered in a controlled manner. The ability to control the current distribution along its...
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An active integrated antenna may be defined as a radiating element on which the current distribution along the structure may be altered in a controlled manner. The ability to control the current distribution along its structure is the unique feature of this class of antennas and gives it its primary advantage. With this ability, radiation characteristics such as pattern shape, axial ratio, and gain may all be controlled. An antenna configuration with integrated active devices has been developed [1]. The resultant topology is a microstrip transmission line configuration with cascade distributed amplifiers. This active antenna has been designed, modelled, fabricated, and its radiation characteristics measured. The above capabilities of controlling the radiation characteristics have been verified. The prototype active antenna utilized three packaged amplifiers and a microstrip transmission line on a Duroid substrate (ε r =2.94) (Figure 1). To facilitate the fabrication of active integrated antennas, the application of Miniature Hybrid Microwave Integrated Circuit (MHMIC) technology was investigated.
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