Fully deadline-coupled planning: One step at a time - Nirkhe,M.; Kraus,S.; Perlis, Don (Methodologies for Intelligent Systems, 1991)

Nonmonotonicity and the scope of reasoning - Etherington,D. W; Kraus,S.; Perlis, Don (Artificial Intelligence, 1991)

A pipeline N-way join algorithm based on the 2-way semijoin program - Roussopoulos, Nick; Kang,H. (IEEE Transactions on Knowledge and Data Engineering, 1991)
The semijoin has been used as an effective operator in reducing data transmission and processing over a network that allows forward size reduction of relations and intermediate results generated during the processing of a distributed query. The authors propose a relational operator, two-way semijoin, which enhanced the semijoin with backward size reduction capability for more cost-effective query processing. A pipeline N-way join algorithm for joining the reduced relations residing on N sites is introduced. The main advantage of this algorithm is that it eliminates the need for transferring and storing intermediate results among the sites. A set of experiments showing that the proposed algorithm outperforms all known conventional join algorithms that generate intermediate results is included
Keywords: 2-way semijoin program; backward size reduction; Bandwidth; Computer networks; Costs; Data communication; data transmission; Database systems; database theory; Delay; distributed databases; distributed query; forward size reduction; intermediate results; Local area networks; network; Parallel algorithms; pipeline N-way join algorithm; pipeline processing; Pipelines; programming theory; Query processing; Relational databases; relational operator; SITES; Workstations

Planar graph coloring is not self-reducible, assuming P ≠ NP - Khuller, Samir; Vazirani,Vijay V. (Theoretical Computer Science, 1991)
We show that obtaining the lexicographically first four coloring of a planar graph is NP-hard. This shows that planar graph four-coloring is not self-reducible, assuming P≠ NP. One consequence of our result is that the schema of Jerrum et al. (1986) cannot be used for approximately counting the number of four colorings of a planar graph. These results extend to planar graph k-coloring, for k⩾4.

Polyadenylylation in copia requires unusually distant upstream sequences - Kurkulos,M.; Weinberg,J. M.; Pepling,M. E.; Mount, Stephen M. (Proceedings of the National Academy of SciencesPNAS, 1991)
Retroviruses and related genetic elements generate terminally redundant RNA products by differential polyadenylylation within a long terminal repeat. Expression of the white-apricot (wa) allele of Drosophila melanogaster, which carries an insertion of the 5.1-kilobase retrovirus-like transposable element copia in a small intron, is influenced by signals within copia. By using this indicator, we have isolated a 518-base-pair deletion, 312 base pairs upstream of the copia polyadenylylation site, that is phenotypically like much larger deletions and eliminates RNA species polyadenylylated in copia. This requirement of distant upstream sequences for copia polyadenylylation has implications for the expression of many genetic elements bearing long terminal repeats.

Reasoning about ignorance: A note on the Bush-Gorbachev problem - Kraus,S.; Perlis, Don; Horty,J. F (Fundam. Inform., 1991)

A superfamily of ıt Arabidopsis thaliana retrotransposons - Konieczny,A; Voytas,D. F; Cummings, Michael P.; Ausubel,F. M (Genetics, 1991)
We describe a superfamily of Arabidopsis thaliana retrotransposable elements that consists of at least ten related families designated Ta1-Ta10. The Ta1 family has been described previously. Two genomic clones representing the Ta2 and Ta3 elements were isolated from an A. thaliana (race Landsberg erecta) lambda library using sequences derived from the reverse transcriptase region of Ta1 as hybridization probes. Nucleotide sequence analysis showed that the Ta1, Ta2 and Ta3 families share greater than 75% amino acid identity in pairwise comparisons of their reverse transcriptase and RNase H genes. In addition to Ta1, Ta2 and Ta3, we identified seven other related retrotransposon families in Landsberg erecta, Ta4-Ta10, using degenerate primers and the polymerase chain reaction to amplify a highly conserved region of retrotransposon-encoded reverse transcriptase. One to two copies of elements Ta2-Ta10 are present in the genomes of the A. thaliana races Landsberg erecta and Columbia indicating that the superfamily comprises at least 0.1% of the A. thaliana genome. The nucleotide sequences of the reverse transcriptase regions of the ten element families place them in the category of copia-like retrotransposons and phylogenetic analysis of the amino acid sequences suggests that horizontal transfer may have played a role in their evolution.

Coloring algorithms for K5-minor free graphs - Khuller, Samir (Information Processing Letters, 1990)
In this paper we give an NC algorithm to five color K5-minor free graphs. We also give a polynomial time algorithm to obtain a four coloring for a K5-minor free graph.
Keywords: graph minor; Parallel algorithms; planar graph coloring

An efficient parallel algorithm for channel routing - Krishnamurthy, S.; JaJa, Joseph F. (Computer Design: VLSI in Computers and Processors, 1990. ICCD '90. Proceedings., 1990 IEEE International Conference on, 1990)
The channel-routing of a set of multiterminal nets in the standard two-layer model is considered. The sequential algorithms based on the greedy strategy do not seem to be easily parallelizable. Proposed is an efficient parallel algorithm for routing channels with cyclic constraints. The algorithm runs in time <e1>O</e1>(<e1>n</e1>2/<e1>p</e1>+log2<e1>p</e1>), with <e1>p</e1> processors, on a shared memory parallel random access machine (PRAM) model where 1 les;<e1>p</e1> les;<e1>n</e1>2 radic; and <e1>n</e1> is the size of the input. An efficient adaptation of this algorithm on a Sequent Balance 21000 multiprocessor system is reported
Keywords: 21000; channel; access; algorithm; sequential; algorithms; algorithms; shared; balance; CAD; computational; complexity; parallel; Layout; machine; standard; memory; model; circuit; nets; parallel; Parallel; PRAM; Sequent; random; routing; multiprocessor; system; multiterminal; two-layer

Extending planar graph algorithms to K3,3-free graphs - Khuller, Samir (Information and Computation, 1990)
For several problems, restricting attention to special classes of graphs has yielded better algorithms. In particular, restricting to planar graphs yields efficient parallel algorithms for several graph problems. In this paper we extend these algorithms to K3,3-free graphs, showing that the restriction of planarity is not important. The three problems dealt with are: graph coloring, depth first search, and maximal independent sets. As a corollary we show that K3,3-free graphs are five colorable (this bound is tight).

FORTRAN Programming: A Spiral Approach - Kreitzberg,C.B.; Shneiderman, Ben (Harcourt Brace College Publishers, 1990)

Investigation of the threshold voltage of MOSFETs with position and potential-dependent interface trap distributions using a fixed-point iteration method - Gaitan,M.; Mayergoyz, Issak D; Korman,C.E. (Electron Devices, IEEE Transactions on, 1990)
Simulation results are presented for a MOSFET with position- and energy- (potential-) dependent interface trap distributions that may be typical for devices subjected to interface-trap-producing processes such as hot-electron degradation. The interface-trap distribution is modeled as a Gaussian peak at a given position along the channel, and the energy dependence is derived from <e1>C</e1>-<e1>V</e1> measurements from an MOS capacitor exposed to ionizing radiation. A novel fixed-point technique is used to solve the two-dimensional boundary-value problem. The technique is shown to be globally convergent for arbitrary distributions of interface traps. A comparison of the convergence properties of the Newton and fixed-point methods is presented, and it is shown that for some important cases the Newton technique fails to converge while the fixed-point technique converges with a geometric convergence rate
Keywords: boundary-value; C-V; carriers; insulated; characteristics; Gaussian; Convergence; convergence; hot-electron; degradation; position; dependence; fixed-point; dependent; device; distribution; potential-dependent; distributions; simulation; threshold; effect; electron; field; gate; interface; iteration; method; fixed-point; methods; hot; methods; semiconductor; models; numerical; of; peak; MOSFET; energy; problem; boundary-value; problems; convergence; rate; global; states; iterative; technique; geometric; transistors; interface; trap; voltage; two-dimensional

IPS-2: the second generation of a parallel program measurement system - Miller, B. P; Clark, M.; Hollingsworth, Jeffrey K; Kierstead, S.; Lim,S. -S; Torzewski, T. (IEEE Transactions on Parallel and Distributed Systems, 1990)
IPS, a performance measurement system for parallel and distributed programs, is currently running on its second implementation. IPS's model of parallel programs uses knowledge about the semantics of a program's structure to provide two important features. First, IPS provides a large amount of performance data about the execution of a parallel program, and this information is organized so that access to it is easy and intuitive. Secondly, IPS provides performance analysis techniques that help to guide the programmer automatically to the location of program bottlenecks. The first implementation of IPS was a testbed for the basic design concepts, providing experience with a hierarchical program and measurement model, interactive program analysis, and automatic guidance techniques. It was built on the Charlotte distributed operating system. The second implementation, IPS-2, extends the basic system with new instrumentation techniques, an interactive and graphical user interface, and new automatic guidance analysis techniques. This implementation runs on 4.3BSD UNIX systems, on the VAX, DECstation, Sun 4, and Sequent Symmetry multiprocessor
Keywords: 4.3BSD UNIX systems; automatic guidance techniques; Automatic testing; Charlotte distributed operating system; CPA; DECstation; design concepts; distributed programs; graphical user interface; Graphical user interfaces; Instruments; interactive program analysis; IPS-2; measurement; message systems; network operating systems; Operating systems; parallel program measurement system; parallel programming; parallel programs; Performance analysis; performance analysis techniques; performance evaluation; performance measurement system; Power system modeling; program bottlenecks; program diagnostics; Programming profession; semantics; Sequent Symmetry multiprocessor; shared-memory systems; software tools; Springs; Sun; Sun 4; Unix; VAX

Limited scope and circumscriptive reasoning - Etherington,D. W; Kraus,S.; Perlis, Don (International Journal of Expert Systems, 1990)

On-line algorithms for weighted matching and stable marriages - Khuller, Samir; Mitchell,S. G; Vazirani,V. V (Cornell University, 1990)
We give an on-line deterministic algorithm for the bipartite weighted matching problem that achieves a competitive ratio of $O(n)$. In fact, this algorithm is almost optimal - the lower bound on the performance ratio of any deterministic online algorithm is $Ω (n/ \sqrt{log n})$. We also study the stable marriage problem, where we are interested in the number of unstable pairs produced. We show that the simple "first come, first served" deterministic algorithm yields on the average $O(n$ log $n$) unstable pairs, but in the worst case no deterministic or randomized on-line algorithm can do better that $Ω(n^{2})$ unstable pairs.

The structure, distribution and evolution of the ıt Ta1 retrotransposable element family of ıt Arabidopsis thaliana - Voytas,D. F; Konieczny,A; Cummings, Michael P.; Ausubel,F. M (Genetics, 1990)
The Ta1 elements are a low copy number, copia-like retrotransposable element family of Arabidopsis thaliana. Six Ta1 insertions comprise all of the Ta1 element copies found in three geographically diverse A. thaliana races. These six elements occupy three distinct target sites: Ta1-1 is located on chromosome 5 and is common to all three races (Col-0, Kas-1 and La-0). Ta1-2 is present in two races on chromosome 4 (Kas-1 and La-0), and Ta1-3, also located on chromosome 4, is present only in one race (La-0). The six Ta1 insertions share greater than 96% nucleotide identity, yet are likely to be incapable of further transposition due to deletions or nucleotide changes that alter either the coding capacity of the elements or conserved protein domains required for retrotransposition. Nucleotide sequence comparisons of these elements and the distribution of Ta1 among 12 additional A. thaliana geographical races suggest that Ta1-1 predated the global dispersal of A. thaliana. As the species spread throughout the world, two additional transposition events occurred which gave rise first to Ta1-2 and finally to Ta1-3.

Touchscreen field specification for public access database queries: let your fingers do the walking - Sears,Andrew; Kochavy,Yoram; Shneiderman, Ben (Proceedings of the 1990 ACM annual conference on Cooperation, 1990)
Database query is becoming a common task in public access systems; touchscreens can provide an appealing interface for such a system. This paper explores three interfaces for constructing queries on alphabetic field values with a touchscreen interface; including a QWERTY keyboard, an Alphabetic keyboard, and a Reduced Input Data Entry (RIDE) interface. The RIDE interface allows field values to be entered with fewer “keystrokes” (touches) than either keyboard while eliminating certain errors. In one test database, the RIDE interface required 69% fewer keystrokes than either keyboard interface.

On a triangle counting problem - Khuller, Samir; Mitchell,Joseph S.B. (Information Processing Letters, 1990)
We consider the following problem: given a set S of n points in the plane, we would like to compute for each point pϵS, how many triangles with corners at points in set S contain p. We give an O(n2) algorithm to solve the problem.
Keywords: combinatorics; computational geometry; Range query

Assessing others' knowledge and ignorance - Kraus,S.; Perlis, Don (Proceedings of the 4th International Symposium on Methodologies for Intelligent Systems, 1989)

On computing graph closures - Khuller, Samir (Information Processing Letters, 1989)
The closure of a graph G of n vertices is obtained from G by recursively joining pairs of non-adjacent vertices whose degree sum is at least n until no such pair remains. We give an efficient algorithm to compute the closure using F-heaps. We also define the general closure of a graph and show that computing the general closure is P-complete with respect to log-space transformations.
Keywords: closure; graphs; P-completeness

Efficient parallel algorithms for testing connectivity and finding disjoint s-t paths in graphs - Khuller, Samir; Schieber,B. (Foundations of Computer Science, 1989., 30th Annual Symposium on, 1989)
An efficient parallel algorithm for testing whether a graph <e1>G </e1> is <e1>K</e1>-vertex connected, for any fixed <e1>k</e1>, is presented. The algorithm runs in <e1>O</e1>(log <e1>n</e1>) time and uses <e1>nC</e1>(<e1>n</e1>,<e1>m</e1>) processors on a concurrent-read, concurrent-write parallel random-access machine (CRCW PRAM), where <e1>n </e1> and <e1>m</e1> are the number of vertices and edges of <e1>G</e1> and <e1>C</e1>(<e1>n</e1>,<e1>m</e1>) is the number of processors required to compute the connected components of <e1>G</e1> in logarithmic time. An optimal speedup algorithm for computing connected components would induce an optimal speedup algorithm for testing <e1>k </e1>-vertex connectivity, for any <e1>k</e1> gt;4. To develop the algorithm, an efficient parallel algorithm is designed for the following disjoint <e1>s</e1>-<e1>t</e1> paths problem: Given a graph <e1>G</e1> and two specified vertices <e1>s</e1> and <e1>t</e1>, find <e1>k</e1>-vertex disjoint paths between <e1>s</e1> and <e1>t</e1>, if they exist. If no such paths exist, find a set of at most <e1>k</e1>-1 vertices whose removal disconnects <e1>s</e1> and <e1>t</e1>. The parallel algorithm for this problem runs in <e1>O</e1>(log <e1>n</e1>) time using <e1>C</e1>(<e1>n</e1>,<e1>m</e1>) processors. It is shown how to modify the algorithm to find <e1>k</e1>-edge disjoint paths, if they exist. This yields an efficient parallel algorithm for testing whether a graph <e1>G</e1> is <e1>k</e1>-edge connected, for any fixed <e1>k</e1>. The algorithm runs in <e1>O</e1>(log <e1>n</e1>) time and uses <e1>nC </e1> (<e1>n</e1>,<e1>n</e1>) processors on a CRCW PRAM. Again, an optimal speedup algorithm for computing connected components would induce an optimal speedup algorithm for testing <e1>k</e1>-edge connectivity
Keywords: algorithm; parallel; algorithms; random-access; algorithms; testing; complexity; graph; connectivity; computational; connectivity; optimal; CRCW; disjoint; paths; graphs; k-edge; paths; k-vertex; PRAM; disjoint; s-t; speedup; storage; theory; parallel

Experiences building a syntax-directed editor - Zelkowitz, Marvin V; Kowalchack,B.; Itkin,D.; Herman,L. (Software Engineering Journal, 1989)
The paper presents a set of techniques for building robust software using the development of a microprocessor SUPPORT programming environment as an example. It discusses some of the attributes built into the system to best handle the concerns of portability, functionality, and effectiveness that had to be dealt with for the system to be reliable on a small machine, and it describes some of the choices made to obtain the best use of available hardware
Keywords: applications; editing; editor; engineering; environment; environments; microcomputer; microprocessor; portability; Programming; robust; software; software; Support; syntax-directed; text

Hypertext hands-on! - Shneiderman, Ben; Kearsley,G. (Tech Report HCIL-89-06, 1989)
This innovative book/software package provides the first hands-on nontechnical introduction to hypertext. Hypertext is a computer technology for manipulating information; in a grander sense, it is a new way of reading and writing. With the IBM-PC disket tes provided in this package, you will learn about hypertext by experiencing it. You will discover what it is like to read interactively, to find information according to your own needs and interests. Both the book and the software versions cover the basic concepts of hypertext, typical hypertext applications, and currently available authoring systems. They also raise important design and implementations issues. The book is self-contained an can be read from beginning to end without a computer. The software is also self-contained and, presenting hypertext in hypertext form, can be read in any order you choose. Since the two versions contain largely similar material, they provide an interesting basis for comparison between conventional text presentation and hypertext.

Rational Common Ground in the Sociology of Knowledge - Katz, Jonathan (Philosophy of the social sciences, 1989)

A support tool for teaching computer programming - Zelkowitz, Marvin V; Kowalchack,B.; Itkin,D.; Herman,L. (Issues in software engineering educationIssues in software engineering education, 1989)

The decomposition of a rectangle into rectangles of minimal perimeter - Kong,T.Y; Mount, Dave; Roscoe,AW (SIAM Journal on Computing, 1988)
This paper solves the problem of subdividing a unit square into p rectangles of area 1/p in such a way that the maximal perimeter of a rectangle is as small as possible. The correctness of the solution is proved using the well-known theorems of Menger and Dilworth.

Parallel algorithms for planar graph isomorphism and related problems - JaJa, Joseph F.; Kosaraju,S.R. (Circuits and Systems, IEEE Transactions on, 1988)
Parallel algorithms for planar graph isomorphism and several related problems are presented. Two models of parallel computation are considered: the CREW-PRAM model and the two-dimensional array of processors. The results include <e1>O</e1>( radic;<e1>n</e1>)-time mesh algorithms for finding a good separating cycle and the triconnected components of a planar graph, and for solving the single-function coarsest partitioning problem
Keywords: 2D; algorithms; algorithms; parallel; array; computational; array; CREW-PRAM; coarsest; complexity; graph; components; two-dimensional; COMPUTATION; graph; graph; planar; isomorphism; single-function; model; mesh; models; planar; partitioning; problem; triconnected; processor; theory; parallel

Uniform accountability for multiple modes of reasoning - Kanal,Laveen; Perlis, Don (International Journal of Approximate Reasoning, 1988)
This article discusses various issues surrounding the general debate on knowledge representation methods and argues in favor of the idea that while many methods are necessary, there also must be a kind of unified nature to the enterprise if it is to serve the needs of intelligence. Specific points include the misleading distinction between probabilistic and logical reasoning regarding the notion of truth and also some matters of nonmonotonicity. An effort is made to sample the broad range of approaches in the literature, with an eye toward such a unification.
Keywords: Artificial intelligence; commonsense reasoning; probabilistic logic; probability theory; uncertainty representation

ALEX-an Alexical Programming Language - Kozen,D.; Teitelbaum,T.; Chen,W. Z; Field,J. H; Pugh, William; Vander Zanden,B. T (Cornell University, 1987)
ALEX is an experimental language for high-level parallel programming. It is a testbed for exploring various non-traditional ways of expressing algorithmic ideas, making extensive use of high-resolution color graphics. The language itself is not a programming language in the traditional sense, since there is no lexical syntax. This paper discusses the basic design of the ALEX user interface.

Computer-supported cooperative work (panel): is this REALLY a new field of research? - Greif,Irene; Curtis,Bill; Krasner,Herb; Malone,Thomas W.; Shneiderman, Ben (Proceedings of the SIGCHI/GI conference on Human factors in computing systems and graphics interface, 1987)

On Cost-effectiveness of a Semijoin in Distributed Query Processing. - Kang,Hyunmo; Roussopoulos, Nick (Institute for Systems Research, University of Maryland, College Park, 1987)
The cost-effective reduction of relations by semijoins is the basis of the heuristic approach to distributed query processing. The cost-effectiveness of a semijoin was simply determined in the literature assuming that the local processing cost is negligible compared to the data transmission cost in distributed query processing. However, recently questions have been raised about the validity of the assumption, and some experimental works revealed that the local processing cost is also significant in distributed query processing. In this paper, we are concerned with the cost-effectiveness of a semijoin considering the local processing cost as well as the data transmission cost. To measure the effectiveness of a semijoin in terms of the local processing cost, we introduce the join sequence in which the relations are joined at the result site to answer the query. A dynamic programming algorithm is developed to generate the optimal join sequence for a given query. A simple heuristic algorithm is also developed to generate a join sequence for a given query.
Keywords: Technical Report

The decomposition of a square into rectangles of minimal perimeter - Kong,T.Y; Mount, Dave; Werman,Michael (Discrete Applied Mathematics, 1987)
This paper solves the problem of subdividing a unit square into p rectangles of area 1/p in such a way that the maximal perimeter of a rectangle is as small as possible. The correctness of the solution is proved using the well-known theorems of Menger and Dilworth.

Using 2-way Semijoins in Distributed Query Processing. - Kang,Hyunmo; Roussopoulos, Nick (Institute for Systems Research, University of Maryland, College Park, 1987)
In distributed query processing, the semijoin has been used as an effective operator in reducing relations referenced in the query to reduce the total amount of data transmission. In this paper, we propose a new relational algebra operator, 2-way semijoin, which is an extended version of the semijoin, for more cost- effective distributed query processing. The 2-way semijoin is compared to the semijoin in terms of the reduction power and the propagation of reduction effects. We show that the 2-way semijoin has more reduction power than the semijoin and that the propagation of reduction effects by the 2-way semijoin is further than by the semijoin.
Keywords: Technical Report

Principles and techniques in the design of ADMS+((advanced data-base management system)) - Roussopoulos, Nick; Kang,H. (Computer, 1986)

The Engineering of an Environment on Small Machines - Zelkowitz, Marvin V; Elgot,J.; Itkin,D.; Kowalchack,B.; Maggio,M. (Proceedings of the IEEE 1st International Conference on Computer Workstations, 1985)

The Structure of Information in Online and Paper Technical Manuals - Weldon,Linda J.; Koved,Larry; Shneiderman, Ben (Proceedings of the Human Factors and Ergonomics Society Annual MeetingProceedings of the Human Factors and Ergonomics Society Annual Meeting, 1985)
An experiment was conducted to compare online computer manuals to paper manuals. For each type of manual there were two different database structures – a linear (sequential) structure and a tree structure. The results showed that people using the paper manuals were faster at performing a switch setting task based on information in the manual than were people using the online manuals. No significant differences were found in speed of performance between the linear and tree structures. Nor were there any differences in the number of correct switch settings for the different types of manuals. The subjective evaluation data revealed that the online manuals were rated as better and judged to be more organized than the paper manuals.

GDDT--A graphical design and documentation tool for software development - Roussopoulos, Nick; Kelley,Stephen (Computers & Graphics, 1984)
This paper describes "The Graphical Design and Documentation Tool" (GDDT), a general purpose support system for design and documentation. Self documentation and ease of use are presented as important criteria for such tools. Interactive graphics is introduced as a methodology for creating and maintaining hierarchical representations. The graphical representations of various requirements specification techniques and design tools are supported by an extended network model which supports hierarchical decomposition of structures. GDDT is proposed as a general purpose design tool which supports the most common logical constructions of both requirements specification and design methodologies and yet has a high level human interface which makes it easy to learn and use.

Monitoring an Ada software development - Basili, Victor R.; Chang,Shih; Gannon,John; Katz,Elizabeth; Panlilio-Yap,N. Monina; Ramsey,Connie Loggia; Zelkowitz, Marvin V; Bailey,John; Kruesi,Elizabeth; Sheppard,Sylvia (ACM SIG Ada Letters, 1984)

A Relational Database to Support Graphical Design and Documentation - Roussopoulos, Nick; Kelley,S. (Databases for Business and Office Applications, Database Week, 1983)

The U1 small nuclear RNA-protein complex selectively binds a 5′ splice site in vitro - Mount, Stephen M.; Pettersson,Ingvar; Hinterberger,Monique; Karmas,Aavo; Steitz,Joan A. (Cell, 1983)
The ability of purified U1 small nuclear RNA-protein complexes (U1 snRNPs) to bind in vitro to two RNAs transcribed from recombinant DNA clones by bacteriophage T7 RNA polymerase has been studied. A transcript which contains sequences corresponding to the small intron and flanking exons of the major mouse beta-globin gene is bound in marked preference to an RNA devoid of splice site sequences. The site of U1 snRNP binding to the globin RNA has been defined by T1 ribonuclease digestion of the RNA-U1 snRNP complex. A 15-17-nucleotide region, including the 5' splice site, remains undigested and complexed with the snRNP such that it can be co-precipitated by antibodies directed against the U1 snRNP. Partial proteinase K digestion of the U1 snRNP abolishes interaction with the globin RNA, indicating that the snRNP proteins contribute significantly to RNA binding. No RNA cleavage, splicing, or recognition of the 3' splice site by U1 snRNPs has been detected. Our results are discussed in terms of the probable role of U1 snRNPs in the messenger RNA splicing of eucaryotic cell nuclei.

Structure and function of small ribonucleoproteins from eukaryotic cells - Steitz,J. A.; Berg,C; Gottlieb,E.; Hardin,J A; Hashimoto,C; Hendrick,J P; Hinterberger,M.; Krikeles,M; Lerner,M R; Mount, Stephen M. (Princess Takamatsu symposiaInt. Symp. Princess Takamatsu Cancer Res. Fund, 1982)
Autoantibodies from patients with systemic lupus erythematosus and other related diseases have been used to identify and study small RNA-protein complexes from mammalian cells. Properties of three previously described and several new classes of small ribonucleoproteins (RNPs) are reviewed. The sequence of Drosophila U1 RNA reveals that the region proposed to pair with 5' splice junctions is conserved, while that proposed to interact with 3' junctions diverges; this forces some revision of the model for U1 small nuclear (sn)RNP participation in hnRNA splicing. Further characterization of the Ro and La small RNPs has shown that the Ro small cytoplasmic (sc)RNPs are a subclass of La RNPs. Both tRNA and 5S rRNA precursors are at least transiently associated with the La protein. This raises the possibility that the La protein may be an RNA polymerase III transcription factor.
Keywords: Antigen-Antibody Complex; Autoantibodies; HUMANS; Lupus Erythematosus, Systemic; Nucleoproteins; Ribonucleoproteins; RNA Polymerase III; Transcription, Genetic

Correspondence from Correspondence - Aloimonos, J.; Kamgar-Parsi,Behrooz (Optical Society of America, Topical Meeting on Machine Vision, 1980)
Image matching (or registration), is in general terms, aligning two identical or similar images or parts of images, and it is basic to a number of vision problems. These include optical nagivation (also known as motion analysis), stereo image interpretation, object analysis, change detection and others. The difficult part of all these problems, is the matching problem, i.e., the computation of the correspondence of elements in the different views. The computation of correspondence, in both the stereo and the motion problem is impossible without the use of some assumptions about the visual world and various researchers have proposed several theories for the computation of visual correspondence that worked well for the domains that fitted their assumptions. Studied here is the problem of the computation of visual correspondence, under the assumption that some values of the correspondence function are already known. The mathematical constraints that are needed for growing a solution for the correspondence function from points where its value is known are developed.
Keywords: ALIGNMENT; COMPUTATION; Error analysis; IMAGE PROCESSING; IMAGES; STEREOSCOPIC VISION; VECTORS (MATHEMATICS)

Pattern Recognition - Kanal,L. N; Agrawala, Ashok K. (Computer Science Center, University of Maryland, 1973)

The Elements of FORTRAN Style: Techniques for Effective Programming - Kreitzberg,Charles B; Shneiderman, Ben (Harcourt Brace College Publishers, 1972)