The Experts below are selected from a list of 39 Experts worldwide ranked by ideXlab platform
Gonzalo Navarro - One of the best experts on this subject based on the ideXlab platform.
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SPIRE - Fast, Small, and Simple Document Listing on Repetitive Text Collections.
String Processing and Information Retrieval, 2020Co-Authors: Dustin Cobas, Gonzalo NavarroAbstract:Document listing on string collections is the task of finding all documents where a Pattern appears. It is regarded as the most fundamental document retrieval problem, and is useful in various applications. Many of the fastest-growing string collections are composed of very similar documents, such as versioned code and document collections, genome repositories, etc. Plain Pattern-matching indexes designed for repetitive text collections achieve orders-of-magnitude reductions in space. Instead, there are not many analogous indexes for document retrieval. In this paper we present a simple document listing index for repetitive string collections of total length n that lists the \( ndoc \) distinct documents where a Pattern of length m appears in time \({{\,\mathrm{\mathcal {O}}\,}}(m+ ndoc \cdot \lg n)\). We exploit the repetitiveness of the document array (i.e., the suffix array coarsened to document identifiers) to grammar-compress it while precomputing the answers to nonterminals, and store them in grammar-compressed form as well. Our experimental results show that our index sharply outperforms existing alternatives in the space/time tradeoff map.
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Fast, Small, and Simple Document Listing on Repetitive Text Collections
arXiv: Data Structures and Algorithms, 2019Co-Authors: Dustin Cobas, Gonzalo NavarroAbstract:Document listing on string collections is the task of finding all documents where a Pattern appears. It is regarded as the most fundamental document retrieval problem, and is useful in various applications. Many of the fastest-growing string collections are composed of very similar documents, such as versioned code and document collections, genome repositories, etc. Plain Pattern-matching indexes designed for repetitive text collections achieve orders-of-magnitude reductions in space. Instead, there are not many analogous indexes for document retrieval. In this paper we present a simple document listing index for repetitive string collections of total length $n$ that lists the $ndoc$ distinct documents where a Pattern of length $m$ appears in time $\mathcal{O}(m+ndoc \cdot \log n)$. We exploit the repetitiveness of the document array (i.e., the suffix array coarsened to document identifiers) to grammar-compress it while precomputing the answers to nonterminals, and store them in grammar-compressed form as well. Our experimental results show that our index sharply outperforms existing alternatives in the space/time tradeoff map.
Dustin Cobas - One of the best experts on this subject based on the ideXlab platform.
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SPIRE - Fast, Small, and Simple Document Listing on Repetitive Text Collections.
String Processing and Information Retrieval, 2020Co-Authors: Dustin Cobas, Gonzalo NavarroAbstract:Document listing on string collections is the task of finding all documents where a Pattern appears. It is regarded as the most fundamental document retrieval problem, and is useful in various applications. Many of the fastest-growing string collections are composed of very similar documents, such as versioned code and document collections, genome repositories, etc. Plain Pattern-matching indexes designed for repetitive text collections achieve orders-of-magnitude reductions in space. Instead, there are not many analogous indexes for document retrieval. In this paper we present a simple document listing index for repetitive string collections of total length n that lists the \( ndoc \) distinct documents where a Pattern of length m appears in time \({{\,\mathrm{\mathcal {O}}\,}}(m+ ndoc \cdot \lg n)\). We exploit the repetitiveness of the document array (i.e., the suffix array coarsened to document identifiers) to grammar-compress it while precomputing the answers to nonterminals, and store them in grammar-compressed form as well. Our experimental results show that our index sharply outperforms existing alternatives in the space/time tradeoff map.
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Fast, Small, and Simple Document Listing on Repetitive Text Collections
arXiv: Data Structures and Algorithms, 2019Co-Authors: Dustin Cobas, Gonzalo NavarroAbstract:Document listing on string collections is the task of finding all documents where a Pattern appears. It is regarded as the most fundamental document retrieval problem, and is useful in various applications. Many of the fastest-growing string collections are composed of very similar documents, such as versioned code and document collections, genome repositories, etc. Plain Pattern-matching indexes designed for repetitive text collections achieve orders-of-magnitude reductions in space. Instead, there are not many analogous indexes for document retrieval. In this paper we present a simple document listing index for repetitive string collections of total length $n$ that lists the $ndoc$ distinct documents where a Pattern of length $m$ appears in time $\mathcal{O}(m+ndoc \cdot \log n)$. We exploit the repetitiveness of the document array (i.e., the suffix array coarsened to document identifiers) to grammar-compress it while precomputing the answers to nonterminals, and store them in grammar-compressed form as well. Our experimental results show that our index sharply outperforms existing alternatives in the space/time tradeoff map.
Susumu Sugiyama - One of the best experts on this subject based on the ideXlab platform.
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Fabrication and simulation of novel crown-shaped microneedle array
Biomedical Applications of Micro- and Nanoengineering II, 2005Co-Authors: Sommawan Khumpuang, Susumu SugiyamaAbstract:Recently, a novel crown-shaped microneedle array fabricated by deep X-ray lithography so called, quadruplets-microneedle array was reported. The microneedle requires no hole-fabrication whilst still can be used for a blood extraction system. Due to its quadruped tip, a deep channel formed by the space between each spike is used for storing blood by a capillary force. The particular shape of the microneedle is unrealizable by other microfabrication technology apart from PCT(Plain-Pattern to Cross-section Transfer) technique. Nanoscaled tips and sloped side-wall of the structure ease a smooth skin-penetration. A model for simulating the capillary height of the extracted blood for this specific shape has been developed since the typical capillary theory is suitable for the only tube shape of liquid channel. The result of simulation conforms to the practical extraction test of the microneedle. The amount of blood retained inside the microneedle can be predicted by the height obtained from the simulation. Besides the PCT technique, the electroforming of Nickel has been demonstrated in order to fabricate the mold. The injections of polycarbonate is then performed for final structures. The cost of each microneedle array after a large volume-production has been dumped to be less than a US dollar. In this paper, the fabrication process and capillary models for individual simulation of the quadruplets-microneedle will be reported.
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Plain Pattern to cross section transfer pct technique for deep x ray lithography and applications
Journal of Micromechanics and Microengineering, 2004Co-Authors: Susumu Sugiyama, Sommawan Khumpuang, Gaku KawaguchiAbstract:This paper presents a novel fabrication method for three-dimensional microstructures using deep x-ray lithography. The microstructures were fabricated including sloped sidewalls and curved surfaces by exposing a synchrotron radiation beam to a moving x-ray resist. The technique, the so-called Plain-Pattern to cross-section transfer (PCT) technique, has been developed as an extension to conventional 2.5-dimension lithography. The fabrication of PMMA microstructures has been demonstrated with surfaces as smooth as 10 nm of RMS roughness. Various applications, e.g., micro-optic, bio-medical and some components of MEMS devices have been realized. Two microstructures have been given as examples: microlens arrays and microneedle arrays. The resulting arrays can be employed to fabricate moulds by electro-deposition for further batch-processing using the LIGA process.
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Quadruptlets-Microneedle Array for Blood Extraction
2004Co-Authors: G Kawaguchi, S Khumpuang, Susumu SugiyamaAbstract:A novel fabrication of painless microneedle array using Synchrotron Radiation lithography with PMMA (Polymethylmethacrylate) is presented in this paper. The microneedles were shaped by Plain-Pattern to Crosssection Technique (PCT). 4 Patterns of X-ray mask were investigated and tested then the optimal one has been selected. The 1024(32x32) quadruplets-needles are consisted in 1x1 cm 2 chip. The crown-shaped structure with 4 tips microneedle can be usehd without the consideration of holes for blood extraction. The tip-size in nano-scale has also been approached. Fabrication of the PMMA microneedle is applicable for LIGA technique. The electroplating of metal and injection of a plastic material can be done for batch production.
Sommawan Khumpuang - One of the best experts on this subject based on the ideXlab platform.
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Fabrication and simulation of novel crown-shaped microneedle array
Biomedical Applications of Micro- and Nanoengineering II, 2005Co-Authors: Sommawan Khumpuang, Susumu SugiyamaAbstract:Recently, a novel crown-shaped microneedle array fabricated by deep X-ray lithography so called, quadruplets-microneedle array was reported. The microneedle requires no hole-fabrication whilst still can be used for a blood extraction system. Due to its quadruped tip, a deep channel formed by the space between each spike is used for storing blood by a capillary force. The particular shape of the microneedle is unrealizable by other microfabrication technology apart from PCT(Plain-Pattern to Cross-section Transfer) technique. Nanoscaled tips and sloped side-wall of the structure ease a smooth skin-penetration. A model for simulating the capillary height of the extracted blood for this specific shape has been developed since the typical capillary theory is suitable for the only tube shape of liquid channel. The result of simulation conforms to the practical extraction test of the microneedle. The amount of blood retained inside the microneedle can be predicted by the height obtained from the simulation. Besides the PCT technique, the electroforming of Nickel has been demonstrated in order to fabricate the mold. The injections of polycarbonate is then performed for final structures. The cost of each microneedle array after a large volume-production has been dumped to be less than a US dollar. In this paper, the fabrication process and capillary models for individual simulation of the quadruplets-microneedle will be reported.
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Plain Pattern to cross section transfer pct technique for deep x ray lithography and applications
Journal of Micromechanics and Microengineering, 2004Co-Authors: Susumu Sugiyama, Sommawan Khumpuang, Gaku KawaguchiAbstract:This paper presents a novel fabrication method for three-dimensional microstructures using deep x-ray lithography. The microstructures were fabricated including sloped sidewalls and curved surfaces by exposing a synchrotron radiation beam to a moving x-ray resist. The technique, the so-called Plain-Pattern to cross-section transfer (PCT) technique, has been developed as an extension to conventional 2.5-dimension lithography. The fabrication of PMMA microstructures has been demonstrated with surfaces as smooth as 10 nm of RMS roughness. Various applications, e.g., micro-optic, bio-medical and some components of MEMS devices have been realized. Two microstructures have been given as examples: microlens arrays and microneedle arrays. The resulting arrays can be employed to fabricate moulds by electro-deposition for further batch-processing using the LIGA process.
S Khumpuang - One of the best experts on this subject based on the ideXlab platform.
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Quadruptlets-Microneedle Array for Blood Extraction
2004Co-Authors: G Kawaguchi, S Khumpuang, Susumu SugiyamaAbstract:A novel fabrication of painless microneedle array using Synchrotron Radiation lithography with PMMA (Polymethylmethacrylate) is presented in this paper. The microneedles were shaped by Plain-Pattern to Crosssection Technique (PCT). 4 Patterns of X-ray mask were investigated and tested then the optimal one has been selected. The 1024(32x32) quadruplets-needles are consisted in 1x1 cm 2 chip. The crown-shaped structure with 4 tips microneedle can be usehd without the consideration of holes for blood extraction. The tip-size in nano-scale has also been approached. Fabrication of the PMMA microneedle is applicable for LIGA technique. The electroplating of metal and injection of a plastic material can be done for batch production.
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Novel-shaped microneedle arrays for multiple uses of bio-medical applications
Proceedings. 7th International Conference on Solid-State and Integrated Circuits Technology 2004., 2004Co-Authors: S Khumpuang, S. SusumuAbstract:Microneedle arrays fabricated by synchrotron radiation deep X-ray lithography are presented in this work. Two types of plastic microneedle array are introduced; hollow microneedle array and quadruplets-microneedle array. The quadruplets-microneedle array has been designed for substitution of the hollow microneedle array in the case that the external pumping facility is disconnected. With the new design and fabrication technique of our research group, PCT (Plain-Pattern to cross-section transfer), the crown-shape of the microneedle has been fabricated and utilized as a blood extraction tool. The advantage is, the needle employs capillary force to draw the liquid. However, in the purpose of drug delivery, the fabrication of a hollow microneedle by the same technique is also reported. In this work, an investigation on several designs of X-ray mask Pattern was done. The results of 3D shapes have been considered in order to approach higher strength for penetrating through the skin. Although the test of the hollow microneedle for drug deliver has not yet been demonstrated due to the requirement of an external pumping tool, the extraction test of quadruplets-microneedle was illustrated.