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Optical and infrared continuum polarization from the interstellar medium is driven by radiative processes aligning the grains with the magnetic field. While a quantitative, predictive theory of Radiative Alignment Torques (RAT) exists and has been extensively tested, several parameters of the theory remain to be fully constrained. In a recent paper, \citet{medan2019} showed that the polarization efficiency (and therefore grain alignment efficiency) at different locations in the wall of the Local Bubble (LB) could be modeled as proportional to the integrated light intensity from the surrounding stars and OB associations. Here we probe that relationship at high radiation field intensities by studying the extinction and polarization in the two reflection nebulae IC\,59 and IC\,63 in the Sh 2-185 H II region, illuminated by the B0 IV star $\gamma$ Cassiopeia. We combine archival visual polarimetry with new 7-band photometry in the Vilnius system, to derive the polarization efficiency from the material. We find that the same linear relationship seen in the Local Bubble wall also applies to the Sh 2-185 region, strengthening the conclusion from the earlier study., Comment: 31 pages, 11 figures, 4 tables (data under tables will be uploaded to CDS), Accepted for publication in AJ

Background: Habitat is the foundation for healthy and productive fisheries. For fish that require substrate for spawning, lack of appropriate spawning substrate is inherently limiting and a lack of access to suitable spawning habitat will lead to population collapse. To ensure management resources are being allocated wisely and conservation targets are being achieved, there is an increased need to consider the effectiveness of techniques to enhance or create habitat that has been lost. The aim of this systematic review was to assess the effectiveness of techniques c

The open cluster IC 4996 in Cygnus and its vicinity are investigated by applying a two-dimensional photometric classification of stars measured in the Vilnius seven-color photometric system. Cluster members are identified by applying distances based on the Gaia DR2 parallaxes and the point vector diagram of the Gaia DR2 proper motions. For some B-type stars, spectroscopic MK types are also obtained from the Asiago spectra and collected from the literature. New parameters of the cluster are derived. The interstellar extinction $A_V$ covers a wide range of values, from 1.3 to 2.4 mag; the mean value in the central part of the cluster is 1.8 mag. The cluster distance is 1915 $\pm$ 110 pc, and its age is within 8-10 Myr. The cluster exhibits a long sequence from early-B to G stars, where stars cooler than B8 are in the pre-main-sequence stage. The plot of extinction versus distance shows a steep rise of $A_V$ up to 1.6 mag at 700-800 pc, which is probably related to dust clouds at the edge of the Great Cygnus Rift. The next increase in extinction by an additional 0.8 mag at $d$ $\geq$ 1.7 kpc is probably related to the associations Cyg OB1 and Cyg OB3. The cluster IC 4996 does not belong to the Cyg OB1 association, which is located closer to the Sun, at 1682 $\pm$ 116 pc. It seems likely that the cluster and the surrounding O-B stars have a common origin with the nearby association Cyg OB3 since Gaia data show that these stellar groups are located at a similar distance., Comment: 7 pages, 5 figures, updated acknowledgements and references for the use of Gaia data

The open cluster IC 4996 in Cygnus and its vicinity are investigated by applying a two-dimensional photometric classification of stars measured in the Vilnius seven-color photometric system. Cluster members are identified by applying distances based on the Gaia DR2 parallaxes and the point vector diagram of the Gaia DR2 proper motions. For some B-type stars, spectroscopic MK types are also obtained from the Asiago spectra and collected from the literature. New parameters of the cluster are derived. The interstellar extinction $A_V$ covers a wide range of values, from 1.3 to 2.4 mag; the mean value in the central part of the cluster is 1.8 mag. The cluster distance is 1915 $\pm$ 110 pc, and its age is within 8-10 Myr. The cluster exhibits a long sequence from early-B to G stars, where stars cooler than B8 are in the pre-main-sequence stage. The plot of extinction versus distance shows a steep rise of $A_V$ up to 1.6 mag at 700-800 pc, which is probably related to dust clouds at the edge of the Great Cygnus Rift. The next increase in extinction by an additional 0.8 mag at $d$ $\geq$ 1.7 kpc is probably related to the associations Cyg OB1 and Cyg OB3. The cluster IC 4996 does not belong to the Cyg OB1 association, which is located closer to the Sun, at 1682 $\pm$ 116 pc. It seems likely that the cluster and the surrounding O-B stars have a common origin with the nearby association Cyg OB3 since Gaia data show that these stellar groups are located at a similar distance., Comment: 7 pages, 5 figures, updated acknowledgements and references for the use of Gaia data

Discovering periodic patterns from historical information is a computationally hard problem due to the large amounts of historical data to be analyzed and due to a high complexity of the patterns. This work shows how the derivations rules for periodic patterns can be applied to discover complex patterns in case of logs of events. The paper defines a concept of periodic pattern and its validation in a workload trace created from the logs of events. A system of derivations rules that transforms periodic patterns into the logically equivalent ones is proposed. The paper presents a systematic approach based on the system of derivation rules to discovery of periodic patterns in logs of events.

The typical algorithms for optimization of query processing in database systems do not take under the consideration the availability of different types and sizes of persistent and transient storage resource that can be used to speed up the internal query processing. It is well known that appropriate allocation of storage resources for the internal query processing may significantly improve performance. This paper describes the new algorithms for automatic management of multilevel transient and persistent storage resources in order to optimize the performance of query processing in a database system. The algorithms presented in the paper process the concurrently submitted queries and discover the common query processing plans. The algorithms estimate the query processing costs and choose the best allocation of multilevel storage resources to optimise the overall internal query processing costs. The paper presents the outcomes of experiments that confirm the improvements in performance through appropriate allocation of multilevel storage for the internal query processing.

This work considers a problem of optimal query processing in heterogeneous and distributed database systems. A global query sub- mitted at a local site is decomposed into a number of queries processed at the remote sites. The partial results returned by the queries are in- tegrated at a local site. The paper addresses a problem of an optimal scheduling of queries that minimizes time spend on data integration of the partial results into the final answer. A global data model defined in this work provides a unified view of the heterogeneous data structures located at the remote sites and a system of operations is defined to ex- press the complex data integration procedures. This work shows that the transformations of an entirely simultaneous query processing strate- gies into a hybrid (simultaneous/sequential) strategy may in some cases lead to significantly faster data integration. We show how to detect such cases, what conditions must be satisfied to transform the schedules, and how to transform the schedules into the more efficient ones.

This work considers a problem of optimal query processing in heterogeneous and distributed database systems. A global query sub- mitted at a local site is decomposed into a number of queries processed at the remote sites. The partial results returned by the queries are in- tegrated at a local site. The paper addresses a problem of an optimal scheduling of queries that minimizes time spend on data integration of the partial results into the final answer. A global data model defined in this work provides a unified view of the heterogeneous data structures located at the remote sites and a system of operations is defined to ex- press the complex data integration procedures. This work shows that the transformations of an entirely simultaneous query processing strate- gies into a hybrid (simultaneous/sequential) strategy may in some cases lead to significantly faster data integration. We show how to detect such cases, what conditions must be satisfied to transform the schedules, and how to transform the schedules into the more efficient ones.

This work considers a problem of optimal query processing in heterogeneous and distributed database systems. A global query sub- mitted at a local site is decomposed into a number of queries processed at the remote sites. The partial results returned by the queries are in- tegrated at a local site. The paper addresses a problem of an optimal scheduling of queries that minimizes time spend on data integration of the partial results into the final answer. A global data model defined in this work provides a unified view of the heterogeneous data structures located at the remote sites and a system of operations is defined to ex- press the complex data integration procedures. This work shows that the transformations of an entirely simultaneous query processing strate- gies into a hybrid (simultaneous/sequential) strategy may in some cases lead to significantly faster data integration. We show how to detect such cases, what conditions must be satisfied to transform the schedules, and how to transform the schedules into the more efficient ones.

This work considers a problem of optimal query processing in heterogeneous and distributed database systems. A global query sub- mitted at a local site is decomposed into a number of queries processed at the remote sites. The partial results returned by the queries are in- tegrated at a local site. The paper addresses a problem of an optimal scheduling of queries that minimizes time spend on data integration of the partial results into the final answer. A global data model defined in this work provides a unified view of the heterogeneous data structures located at the remote sites and a system of operations is defined to ex- press the complex data integration procedures. This work shows that the transformations of an entirely simultaneous query processing strate- gies into a hybrid (simultaneous/sequential) strategy may in some cases lead to significantly faster data integration. We show how to detect such cases, what conditions must be satisfied to transform the schedules, and how to transform the schedules into the more efficient ones.

In data integration systems a user request issued at a central site is decomposed into a number of sub-requests, which later on are processed at the remote sites. The results are sent back to a central site for data integration and the results of integration are returned to a user. Data integration systems often failed to show its best performance due to unpredictable data arrival rate. Traditionally, data integration requires the complete results from the remote sites to be available at a central site before final computations begin. An online integration system starts and continues the computations at the central site shortly after every piece of data is received from the remote sites. Execution of online integration plan in static scheduling strategy causes poor performance of data integration system as unnecessary computations are executed in some circumstances. This paper proposes a dynamic scheduling for online integration plans, which employs data increment monitoring system which is able to dynamically change the data integration plans whenever it is necessary.

Determining the distance to the open cluster M29 (NGC 6913) has proven difficult, with distances determined by various authors differing by a factor of two or more. To solve this problem, we have initiated a new photometric investigation of the cluster in the Vilnius seven-color photometric system, supplementing it with available data in the BV and JHKs photometric systems and spectra of the nine brightest stars of spectral classes O and B. Photometric spectral classes and luminosities of 260 stars in a 15' x 15' area down to V = 19 mag are used to investigate the interstellar extinction run with distance and to estimate the distance of the Great Cygnus Rift, approximately 800 pc. The interstellar reddening law in the optical and near-infrared regions is found to be close to normal, with the ratio of extinction to color excess R(BV) = 2.87. The extinction A(V) of cluster members is between 2.5 and 3.8 mag, with a mean value of 2.97 mag, or E(B-V) = 1.03. The average distance of eight stars of spectral types O9 B2 is 1.54 +/- 0.15 kpc. Two stars from the seven brightest stars are field stars: HDE 229238 is a background B0.5 supergiant and HD 194378 is a foreground F star. In the intrinsic color magnitude diagram, seven fainter stars of spectral classes B3 B8 are identified as possible members of the cluster. The 15 selected members of the cluster of spectral classes O9 B8, together with the isochrones from the Padova database, give the age of the cluster as 5 +/- 1 Myr., The Astronomical Journal, 148:89 (9pp), 2014 November. The original document contains color images.

Determining the distance to the open cluster M29 (NGC 6913) has proven difficult, with distances determined by various authors differing by a factor of two or more. To solve this problem, we have initiated a new photometric investigation of the cluster in the Vilnius seven-color photometric system, supplementing it with available data in the BV and JHKs photometric systems and spectra of the nine brightest stars of spectral classes O and B. Photometric spectral classes and luminosities of 260 stars in a 15 ' 15 ' area down to V = 19 mag are used to investigate the interstellar extinction run with distance and to estimate the distance of the Great Cygnus Rift, 800 pc. The interstellar reddening law in the optical and near-infrared regions is found to be close to normal, with the ratio of extinction to color excess RBV = 2.87. The extinction AV of cluster members is between 2.5 and 3.8 mag, with a mean value of 2.97 mag, or EB V = 1.03. The average distance of eight stars of spectral types O9 B2 is 1.54 0.15 kpc. Two stars from the seven brightest stars are field stars: HDE 229238 is a background B0.5 supergiant and HD 194378 is a foreground F star. In the intrinsic color magnitude diagram, seven fainter stars of spectral classes B3 B8 are identified as possible members of the cluster. The 15 selected members of the cluster of spectral classes O9 B8 plotted on the log L/LO versus log Teff diagram, together with the isochrones from the Padova database, give the age of the cluster as 5 1 Myr., Published in the Astronomical Journal, v148 n89, Nov 2014. The original document contains color images. Prepared in collaboration with the Institute of Theoretical Physics and Astronomy, Vilnius University, Vilnius, Lithuania, the Vatican Observatory Research Group, Steward Observatory, Tucson, AZ, the INAF Astronomical Observatory of Padova, Asiago, Italy, the Space Telescope Science Institute, Baltimore, MD, and the University School Ignatianum, Cracow, Poland.

2014 IEEE. Information about periodic computations of processes, events, and software components can be used to improve performance of software systems. This work investigates mining periodic patterns of events from historical information related to processes, events, and software components. We introduce a concept of a nested event log that generalizes historical information stored in the application traces, event logs and dynamic profiles. We show how a nested event log can be compressed into a reduced event table and later on converted into a workload histogram suitable for mining periodic patterns of events. The paper defines a concept of periodic pattern and its validation in a workload histogram. We propose two algorithms for mining periodic patterns and we define the quality indicators for the patterns found. We show, that a system of operations on periodic patterns introduced in this work can be used to derive new periodic patterns with some of the quality indicators better from the original ones. The paper is concluded with an algorithm for deriving periodic patterns with the given quality constraints.

2014 IEEE. Information about periodic computations of processes, events, and software components can be used to improve performance of software systems. This work investigates mining periodic patterns of events from historical information related to processes, events, and software components. We introduce a concept of a nested event log that generalizes historical information stored in the application traces, event logs and dynamic profiles. We show how a nested event log can be compressed into a reduced event table and later on converted into a workload histogram suitable for mining periodic patterns of events. The paper defines a concept of periodic pattern and its validation in a workload histogram. We propose two algorithms for mining periodic patterns and we define the quality indicators for the patterns found. We show, that a system of operations on periodic patterns introduced in this work can be used to derive new periodic patterns with some of the quality indicators better from the original ones. The paper is concluded with an algorithm for deriving periodic patterns with the given quality constraints.

2014 IEEE. Information about periodic computations of processes, events, and software components can be used to improve performance of software systems. This work investigates mining periodic patterns of events from historical information related to processes, events, and software components. We introduce a concept of a nested event log that generalizes historical information stored in the application traces, event logs and dynamic profiles. We show how a nested event log can be compressed into a reduced event table and later on converted into a workload histogram suitable for mining periodic patterns of events. The paper defines a concept of periodic pattern and its validation in a workload histogram. We propose two algorithms for mining periodic patterns and we define the quality indicators for the patterns found. We show, that a system of operations on periodic patterns introduced in this work can be used to derive new periodic patterns with some of the quality indicators better from the original ones. The paper is concluded with an algorithm for deriving periodic patterns with the given quality constraints.

2014 IEEE. Information about periodic computations of processes, events, and software components can be used to improve performance of software systems. This work investigates mining periodic patterns of events from historical information related to processes, events, and software components. We introduce a concept of a nested event log that generalizes historical information stored in the application traces, event logs and dynamic profiles. We show how a nested event log can be compressed into a reduced event table and later on converted into a workload histogram suitable for mining periodic patterns of events. The paper defines a concept of periodic pattern and its validation in a workload histogram. We propose two algorithms for mining periodic patterns and we define the quality indicators for the patterns found. We show, that a system of operations on periodic patterns introduced in this work can be used to derive new periodic patterns with some of the quality indicators better from the original ones. The paper is concluded with an algorithm for deriving periodic patterns with the given quality constraints.

Determining the distance to the open cluster M29 (NGC 6913) has proven difficult, with distances determined by various authors differing by a factor of two or more. To solve this problem, we have initiated a new photometric investigation of the cluster in the Vilnius seven-color photometric system supplementing it with available data in the BV and JHK_s photometric systems, and spectra of the nine brightest stars of spectral classes O and B. Photometric spectral classes and luminosities of 260 stars in a 15 arcmin x 15 arcmin area down to V = 19 mag are used to investigate the interstellar extinction run with distance and to estimate the distance of the Great Cygnus Rift, 800 pc. The interstellar reddening law in the optical and near-infrared regions is found to be close to normal, with the ratio of extinction to color excess R(BV) = 2.87. The extinction A(V) of cluster members is between 2.5 to 3.8 mag, with a mean value of 2.97 mag or E(B-V) = 1.03. The average distance of eight stars of spectral types O9-B2 is 1.54 +- 0.15 kpc. Two stars from the seven brightest ones are field stars: HDE 229238 is a background B0.5 supergiant and HD 194378 is a foreground F star. In the intrinsic color-magnitude diagram, seven fainter stars of spectral classes B3-B8 are identified as possible members of the cluster. The 15 selected members of the cluster of spectral classes O9--B8 plotted on the log L/L(sun) vs. log T(eff) diagram, together with the isochrones from the Padova database, give the age of the cluster as 5 +- 1 Myr., Comment: 13 pages, 7 figures Astronomical Journal, accepted on 2014 July 17

Historical information stored in the software system logs, audit trails, traces of user applications, etc. can be analysed to discover the patterns in periodic variations of levels and structures of the past workloads. These patterns allow for the estimation of intensities and structures of the future workloads. The correctly anticipated future workloads are used to improve performance of software systems through appropriate allocation of computing resources and through restructuring of associated system support. This work defines a concept of periodic pattern and presents the algorithms that find the periodic patterns in the traces of elementary and complex operations on data recorded in the system logs.

Determining the distance to the open cluster M29 (NGC 6913) has proven difficult, with distances determined by various authors differing by a factor of two or more. To solve this problem, we have initiated a new photometric investigation of the cluster in the Vilnius seven-color photometric system supplementing it with available data in the BV and JHK_s photometric systems, and spectra of the nine brightest stars of spectral classes O and B. Photometric spectral classes and luminosities of 260 stars in a 15 arcmin x 15 arcmin area down to V = 19 mag are used to investigate the interstellar extinction run with distance and to estimate the distance of the Great Cygnus Rift, 800 pc. The interstellar reddening law in the optical and near-infrared regions is found to be close to normal, with the ratio of extinction to color excess R(BV) = 2.87. The extinction A(V) of cluster members is between 2.5 to 3.8 mag, with a mean value of 2.97 mag or E(B-V) = 1.03. The average distance of eight stars of spectral types O9-B2 is 1.54 +- 0.15 kpc. Two stars from the seven brightest ones are field stars: HDE 229238 is a background B0.5 supergiant and HD 194378 is a foreground F star. In the intrinsic color-magnitude diagram, seven fainter stars of spectral classes B3-B8 are identified as possible members of the cluster. The 15 selected members of the cluster of spectral classes O9--B8 plotted on the log L/L(sun) vs. log T(eff) diagram, together with the isochrones from the Padova database, give the age of the cluster as 5 +- 1 Myr., Comment: 13 pages, 7 figures Astronomical Journal, accepted on 2014 July 17

Magnitudes and color indices in the Vilnius seven-color system were determined for 1752 stars down to V = 19.5 mag in the direction of the open cluster M 29 (NGC 6913). The region is centered at R.A = 20:24, DEC = +38:30 (J2000) and covers an area of 1.5 sq. deg. The photometric data are used to classify about 70% of stars in spectral and luminosity classes and peculiarity types., Published in Baltic Astronomy, v22 p181-221, 2013.

Global information systems provide its users with a centralized and transparent view of many heterogeneous and distributed sources of data. The requests to access data at a central site are decomposed and processed at the remote sites and the results are returned back to a central site. A data integration component of the system processes data retrieved and transmitted from the remote sites accordingly to the earlier prepared data integration plans. This work addresses a problem of static optimization of data integration plans in a global information system. Static optimization means that a data integration plan is transformed into more optimal form before it is used for data integration. We adopt an online approach to data integration where the packets of data transmitted over a wide area network are integrated into the final result as soon as they arrive at a central site. We show how data integration expression obtained from a user request can be transformed into a collection of data integration plans, one for each argument of data integration expression. This work proposes a number of static optimization techniques that change an order operations, eliminate materialization and constant arguments from data integration plans implemented as relational algebra expressions.

A wireless sensor network is an information technology infrastructure capable of processing theoretically unlimited sequences of data commonly called as data streams. dA heterogeneous sensor network consists of sensing nodes creating the streams of atomic data items and clustering nodes joining several data streams into one stream of complex data items and performing the preliminary data processing. This work investigates the microprogramming implementation of join operation at the clustering nodes. We define a data stream join operation and we prove that it can be computed in an incremental way. Then, we propose a number of optimisation techniques for its processing. The micro implementation of join operation on 8-bit microprocessor controller with memory and interfacing ports is derived from the incremental processing algorithm. We describe architecture of firmware implementation of join operation and we propose a network implementation of a number of join modules. The experimental results include testing of join operation on two and many data streams

A wireless sensor network is an information technology infrastructure capable of processing theoretically unlimited sequences of data commonly called as data streams. dA heterogeneous sensor network consists of sensing nodes creating the streams of atomic data items and clustering nodes joining several data streams into one stream of complex data items and performing the preliminary data processing. This work investigates the microprogramming implementation of join operation at the clustering nodes. We define a data stream join operation and we prove that it can be computed in an incremental way. Then, we propose a number of optimisation techniques for its processing. The micro implementation of join operation on 8-bit microprocessor controller with memory and interfacing ports is derived from the incremental processing algorithm. We describe architecture of firmware implementation of join operation and we propose a network implementation of a number of join modules. The experimental results include testing of join operation on two and many data streams

A wireless sensor network is an information technology infrastructure capable of processing theoretically unlimited sequences of data commonly called as data streams. dA heterogeneous sensor network consists of sensing nodes creating the streams of atomic data items and clustering nodes joining several data streams into one stream of complex data items and performing the preliminary data processing. This work investigates the microprogramming implementation of join operation at the clustering nodes. We define a data stream join operation and we prove that it can be computed in an incremental way. Then, we propose a number of optimisation techniques for its processing. The micro implementation of join operation on 8-bit microprocessor controller with memory and interfacing ports is derived from the incremental processing algorithm. We describe architecture of firmware implementation of join operation and we propose a network implementation of a number of join modules. The experimental results include testing of join operation on two and many data streams

A wireless sensor network is an information technology infrastructure capable of processing theoretically unlimited sequences of data commonly called as data streams. dA heterogeneous sensor network consists of sensing nodes creating the streams of atomic data items and clustering nodes joining several data streams into one stream of complex data items and performing the preliminary data processing. This work investigates the microprogramming implementation of join operation at the clustering nodes. We define a data stream join operation and we prove that it can be computed in an incremental way. Then, we propose a number of optimisation techniques for its processing. The micro implementation of join operation on 8-bit microprocessor controller with memory and interfacing ports is derived from the incremental processing algorithm. We describe architecture of firmware implementation of join operation and we propose a network implementation of a number of join modules. The experimental results include testing of join operation on two and many data streams

This work considers the materialized view maintenance in a distributed environment where the collaboration of the operational systems is limited to granting read only access on the selected relational tables. In addition, due to possibly large volumes of source relational tables involved in the view maintenance process and consequently enormous overhead associated with data extracting and transporting, the efficiency issues have been taken into the consideration and some optimization techniques are included in this paper.

This work considers the materialized view maintenance in a distributed environment where the collaboration of the operational systems is limited to granting read only access on the selected relational tables. In addition, due to possibly large volumes of source relational tables involved in the view maintenance process and consequently enormous overhead associated with data extracting and transporting, the efficiency issues have been taken into the consideration and some optimization techniques are included in this paper.

This work considers the materialized view maintenance in a distributed environment where the collaboration of the operational systems is limited to granting read only access on the selected relational tables. In addition, due to possibly large volumes of source relational tables involved in the view maintenance process and consequently enormous overhead associated with data extracting and transporting, the efficiency issues have been taken into the consideration and some optimization techniques are included in this paper.

This work considers the materialized view maintenance in a distributed environment where the collaboration of the operational systems is limited to granting read only access on the selected relational tables. In addition, due to possibly large volumes of source relational tables involved in the view maintenance process and consequently enormous overhead associated with data extracting and transporting, the efficiency issues have been taken into the consideration and some optimization techniques are included in this paper.

Semantic indexing of a video document is a process that performs the identification of elementary and complex semantic units in the indexed document in order to create a semantic index defined as a mapping of semantic units into the sequences of video frames. Semantic content-based video retrieval system is a software system that uses a semantic index built over a collection of video documents to retrieve the sequences of video frames that satisfy the given conditions. This work introduces a new multilevel view of data for the semantic content-based video retrieval systems. At the topmost level, we define an abstract view of data and we express it in a notation of enhanced conceptual modeling suitable for the formal representation of the semantic contents of video documents. A semistructured data model is proposed for the middle level representation of data. At the bottom level we implement a semistructured data model as an object-relational database. The completeness of the proposed approach is demonstrated through the mappings of a conceptual level into a semistructured level and into an object-relational organization of data. The paper describes a system of operations on semistructured data and shows how a sample query can be represented as an expression built from the operations.

Semantic indexing of a video document is a process that performs the identification of elementary and complex semantic units in the indexed document in order to create a semantic index defined as a mapping of semantic units into the sequences of video frames. Semantic content-based video retrieval system is a software system that uses a semantic index built over a collection of video documents to retrieve the sequences of video frames that satisfy the given conditions. This work introduces a new multilevel view of data for the semantic content-based video retrieval systems. At the topmost level, we define an abstract view of data and we express it in a notation of enhanced conceptual modeling suitable for the formal representation of the semantic contents of video documents. A semistructured data model is proposed for the middle level representation of data. At the bottom level we implement a semistructured data model as an object-relational database. The completeness of the proposed approach is demonstrated through the mappings of a conceptual level into a semistructured level and into an object-relational organization of data. The paper describes a system of operations on semistructured data and shows how a sample query can be represented as an expression built from the operations.

Semantic indexing of a video document is a process that performs the identification of elementary and complex semantic units in the indexed document in order to create a semantic index defined as a mapping of semantic units into the sequences of video frames. Semantic content-based video retrieval system is a software system that uses a semantic index built over a collection of video documents to retrieve the sequences of video frames that satisfy the given conditions. This work introduces a new multilevel view of data for the semantic content-based video retrieval systems. At the topmost level, we define an abstract view of data and we express it in a notation of enhanced conceptual modeling suitable for the formal representation of the semantic contents of video documents. A semistructured data model is proposed for the middle level representation of data. At the bottom level we implement a semistructured data model as an object-relational database. The completeness of the proposed approach is demonstrated through the mappings of a conceptual level into a semistructured level and into an object-relational organization of data. The paper describes a system of operations on semistructured data and shows how a sample query can be represented as an expression built from the operations.

Semantic indexing of a video document is a process that performs the identification of elementary and complex semantic units in the indexed document in order to create a semantic index defined as a mapping of semantic units into the sequences of video frames. Semantic content-based video retrieval system is a software system that uses a semantic index built over a collection of video documents to retrieve the sequences of video frames that satisfy the given conditions. This work introduces a new multilevel view of data for the semantic content-based video retrieval systems. At the topmost level, we define an abstract view of data and we express it in a notation of enhanced conceptual modeling suitable for the formal representation of the semantic contents of video documents. A semistructured data model is proposed for the middle level representation of data. At the bottom level we implement a semistructured data model as an object-relational database. The completeness of the proposed approach is demonstrated through the mappings of a conceptual level into a semistructured level and into an object-relational organization of data. The paper describes a system of operations on semistructured data and shows how a sample query can be represented as an expression built from the operations.

Processing of data streams requires the continuous re-computation of end-user applications over the long and steadily increasing sequences of data items. Design and implementation of the applications is always affected by the specific properties of their domains. This work considers the design and implementation of data stream processing applications in the domains where the limited computational resources, constraints imposed on the implementation techniques and specific properties of applications exclude the use of a general purpose data stream management system. We start from an abstract view of a data stream processing application as an n-ary operation on the input streams and we show how to decompose such an operation into an expression over the binary operations on windows and materializations of intermediate results. Then, we show how to implement an application through the integration of atomic applications, each one processing one data stream at a time. The implementation techniques described in the paper include the representation of atomic application as sequences of operation in an XML based language and translation of XML specifications into the programs in an object-oriented programming language.

Vertical partitioning is an effective way of improving performance in the database systems where a significant percentage of query processing time is spent on the full scans of relational tables. Vertical partitioning provides even more compelling performance gains when it is combined with the controlled replication of data in the environments where the processing of queries dominates the data manipulations. This paper proposes a new algorithm that finds a suboptimal vertical partitioning of relational tables under a constraint that certain level of redundancies is acceptable in a database. TIle algorithm is based on a new cost model, which precisely estimates I/O throughput as the total number of physical read/write database operations required to implement a given workload. The solution described in the paper transforms a schema of relational database into a partitioned one and decides which components of the original schema should be replicated as the separate partitions. The experiments conducted in this research and reported in the paper confirm the correctness of the cost model used by the vertical partitioning algorithm and demonstrate the expected performance gains from the partitioning.

Vertical partitioning is an effective way of improving performance in the database systems where a significant percentage of query processing time is spent on the full scans of relational tables. Vertical partitioning provides even more compelling performance gains when it is combined with the controlled replication of data in the environments where the processing of queries dominates the data manipulations. This paper proposes a new algorithm that finds a suboptimal vertical partitioning of relational tables under a constraint that certain level of redundancies is acceptable in a database. TIle algorithm is based on a new cost model, which precisely estimates I/O throughput as the total number of physical read/write database operations required to implement a given workload. The solution described in the paper transforms a schema of relational database into a partitioned one and decides which components of the original schema should be replicated as the separate partitions. The experiments conducted in this research and reported in the paper confirm the correctness of the cost model used by the vertical partitioning algorithm and demonstrate the expected performance gains from the partitioning.

Vertical partitioning is an effective way of improving performance in the database systems where a significant percentage of query processing time is spent on the full scans of relational tables. Vertical partitioning provides even more compelling performance gains when it is combined with the controlled replication of data in the environments where the processing of queries dominates the data manipulations. This paper proposes a new algorithm that finds a suboptimal vertical partitioning of relational tables under a constraint that certain level of redundancies is acceptable in a database. TIle algorithm is based on a new cost model, which precisely estimates I/O throughput as the total number of physical read/write database operations required to implement a given workload. The solution described in the paper transforms a schema of relational database into a partitioned one and decides which components of the original schema should be replicated as the separate partitions. The experiments conducted in this research and reported in the paper confirm the correctness of the cost model used by the vertical partitioning algorithm and demonstrate the expected performance gains from the partitioning.

Vertical partitioning is an effective way of improving performance in the database systems where a significant percentage of query processing time is spent on the full scans of relational tables. Vertical partitioning provides even more compelling performance gains when it is combined with the controlled replication of data in the environments where the processing of queries dominates the data manipulations. This paper proposes a new algorithm that finds a suboptimal vertical partitioning of relational tables under a constraint that certain level of redundancies is acceptable in a database. TIle algorithm is based on a new cost model, which precisely estimates I/O throughput as the total number of physical read/write database operations required to implement a given workload. The solution described in the paper transforms a schema of relational database into a partitioned one and decides which components of the original schema should be replicated as the separate partitions. The experiments conducted in this research and reported in the paper confirm the correctness of the cost model used by the vertical partitioning algorithm and demonstrate the expected performance gains from the partitioning.

During the contract period the spall testing of Ti-6Al-4V has been completed. The series of tests (total 11 tests) at different impact velocities (from 290 m/s to 460 m/s) have been performed and the level of the normal stress sigma (sub F) for the incipient spall as a function of the incident pulse duration tau(Sub C) has been determined. Such analysis has yielded the preliminary data in the form of the critical tensile stress versus the pulse duration, sigma(sub F). The Scanning Electron Microscopy (SEM) observation of the spalled surfaces was performed showing microdimples. Optical microscopy observation of the specimen cross-sections demonstrated presence on the me so-scale a combination of microcracks and adiabatic shearing. Those observations are very helpful to identify the physical mechanism of fracture development. The relief of the material separation leads to a new failure criterion on the mesoscale 1,2. The quantitative statistical analysis of the pictures needs more time and is in progress. A new model of spalling based on two meso- mechanisms of material separation has recently been developed and verified for martensitic armor steel and hard aluminum alloy, 1,2, it confirms all findings by experiment. In order to gain more deep insight on the material behavior during spalling the initial microstructure of the Ti-6Al-4V alloy has been examined by microscopy observation, including chemical treatment of the surfaces. The literature survey on high strain rate behavior and spalling of Ti-6Al-4V alloy is included in this Report.

One of the most difficult problems in the mechanics of kinetic energy projectiles penetrating geological or cementitious target materials is a proper understanding of the frictional properties between the projectile surface and the target. The model developed in this study is limited to a simple definition of the state of the projectile surface as a set of uniformly distributed micro-asperities with the same active height, h = 20 microns, which are subject to fast adiabatic shearing. Although the heat conduction equation has not been solved numerically in this study, a useful approximation of the evolution of temperature in the bulk material was applied. This approximation permitted finding the closed form solution for the homologous bulk temperature, at different sliding conditions. Because evolution of the bulk temperature could be estimated, it also permitted finding the evolution of the coefficient of friction as a function of the sliding velocity. For every definition of the coefficient of friction a substantial decrease of the resistance to sliding at increasing velocities has been found. An open question remains as to the role of the hydrostatic pressure. For example, the experimental data suggest that at constant velocity the coefficient of friction will diminish as a function of pressure as predicted by Eq. (51). Thus, an advantage of the model presented here is that hydrostatic pressure can be taken into consideration in a correct way. Albeit implementation of the friction model in the form of Eq. (51) into numerical codes is rather too early, preliminary trials should be recommended.

This Final Technical Report covers the contract period from 7 Nov 96 to 6 Jan 98. A more detailed information on the progress of this Contract can be found in the previous Interim Reports. During the period under consideration the research has been continued on analyses of experimental results obtained via the Modified Double Shear experimental technique (MDS). This technique has been applied for VAR 4340 steel with the heat treatment to -50 HRC. In order to study the effect of stress concentrators in shear at different rates of loading four MDS geometries have been tested with different stress concentrators, from "standard" geometry to a very sharp notch. A wide loading rate spectrum has been covered, from quasi-static to impact (up to impact velocity ^ 100 m/s). Experiments confirmed that the adiabatic stress concentrators accelerate failure in shear. This mechanism leads to a decrease of the fragmentation energy when the impact velocity is increased. In parallel, the numerical studies for all four geometries have been performed using the FE code ABAQUS. Details of the numerical studies are given in the appendix to this Report. The numerical analyses have confirmed all observations from experiments.

The phenomenon of shear instability and flow localization is investigated in this Report. The ultrahigh strength steel VAR 4340, approx. 52 HRC was tested in shear at wide range of the imposed velocities, from quasi-static to 120 m/s. A new experimental technique of direct impact on double shear specimen was used. Four specimen geometries were tested with different stress concentrators, from standard to a very sharp notch. At loading velocities higher than the threshold value a substantial drop of the failure strains and failure energies was observed. To study this effect a series of FE simulations was run for two notch geometries. An extended FE simulation program was performed on occurrence of the Critical Impact Velocity (CIV) in shear. The FE calculations confirmed experimental result, CIV for VAR 4340 steel approx. 52 HRC is approx. 130 m/s. A substantial drop of the localization energy was found at impact velocities higher than the CIV (130 m/s).

The general procedure of solving the one-velocity Boltzmann equation in the case of plane geometry is presented. It is assumed that the scattering function can be expanded into the finite series of Legendre polynomials. The complete set of eigenfunctions of the Boltzmann equation is found. The orthogonality and completeness of the eigenfunctions are proved. By way of illustration, solutions of some basic problems of neutron diffusion are given. (Author)

Single-pick measurements were made for cutting of artificial samples of rock with uniaxial compressive strength up to 105 MPa, with and without the assistance of a high-pressure water jet from the front or the back, using shearer-adjacent Alpine and Boart picks and Saphintec-type nozzles of 0.3-0.8 mm diameter with water pressures of 1-60 MPa. Pick edge wear, pressure, tangential and side force and dustiness were measured for several selected mining parameters. It was concluded that rotary picks with large-diameter sintered carbide edges are most used, both wear and load increasing less rapidly than for smaller edge diameters. Application of a water jet in front of the cutter improves its lifetime while maintaining the same cutting force, but the best reduction in dust concentration was when the nozzle was placed at the back of the cutter. For reasons of energy consumption, jet diameter and pressure should not exceed 0.50 mm and 20 MPa., Single-pick measurements were made for cutting of artificial samples of rock with uniaxial compressive strength up to 105 MPa, with and without the assistance of a high-pressure water jet from the front or the back, using shearer-adjacent Alpine and Boart picks and Saphintec-type nozzles of 0.3-0.8 mm diameter with water pressures of 1-60 MPa. Pick edge wear, pressure, tangential and side force and dustiness were measured for several selected mining parameters. It was concluded that rotary picks with large-diameter sintered carbide edges are most used, both wear and load increasing less rapidly than for smaller edge diameters. Application of a water jet in front of the cutter improves its lifetime while maintaining the same cutting force, but the best reduction in dust concentration was when the nozzle was placed at the back of the cutter. For reasons of energy consumption, jet diameter and pressure should not exceed 0.50 mm and 20 MPa.