Correctness and Progress Verification of Non-Blocking Programs

The progression of multi-core processors has inspired the development of concurrency libraries that guarantee safety and liveness properties of multiprocessor applications. The difficulty of reasoning about safety and liveness properties in a concurrent environment has led to the development of tools to verify that a concurrent data structure meets a correctness condition or progress guarantee. However, these tools possess shortcomings regarding the ability to verify a composition of data structure operations. Additionally, verification techniques for transactional memory evaluate correctness based on low-level read/write histories, which is not applicable to transactional data structures that use a high-level semantic conflict detection. In my dissertation, I present tools for checking the correctness of multiprocessor programs that overcome the limitations of previous correctness verification techniques. Correctness Condition Specification (CCSpec) is the first tool that automatically checks the correctness of a composition of concurrent multi-container operations performed in a non-atomic manner. Transactional Correctness tool for Abstract Data Types (TxC-ADT) is the first tool that can check the correctness of transactional data structures. TxC-ADT elevates the standard definitions of transactional correctness to be in terms of an abstract data type, an essential aspect for checking correctness of transactions that synchronize only for high-level semantic conflicts. Many practical concurrent data structures, transactional data structures, and algorithms to facilitate non-blocking programming all incorporate helping schemes to ensure that an operation comprising multiple atomic steps is completed according to the progress guarantee. The helping scheme introduces additional interference by the active threads in the system to achieve the designed progress guarantee. Previous progress verification techniques do not accommodate loops whose termination is dependent on complex behaviors of the interfering threads, making these approaches unsuitable. My dissertation presents the first progress verification technique for non-blocking algorithms that are dependent on descriptor-based helping mechanisms

N+N Structures in Present-Day English Word Formation

[Abstract] N+N structures are sequences of two nouns, such as drug addiction or heart attack; often, structures of this type appear to be formations to which speakers and writers resort on the spur of the moment in order to fill a semantic gap, and which will never be used again. However, reasons such as their relevance or their easiness to be understood help them to remain through time as structures which enter the everyday vocabulary of a given language. The present paper is an approach to the consideration that N+N structures are a productive word formation type in Present-Day English. For this reason, I will try to establish which the motivations for their use are and I will make reference to the process of lexicalisation they may undergo. Likewise, I will make use of a corpus of English written texts to illustrate the lexical richness that these formations may provide to the vocabulary of English. The data taken from the corpora show that there is an active progress in the development of new compositional nominal groups

Pulmonary congenital cystic adenomatoid malformation, type I, presenting as a single cyst of the middle lobe in an adult: case report

<p>Abstract</p> <p>Background</p> <p>Congenital cystic adenomatoid malformation (CCAM) of the lung is an uncommon fetal development anomaly of the terminal respiratory structures. The large cyst type usually occurs in stillborn infants or newborn infants with respiratory distress. Cases of CCAM have been previously described in adulthood, more often type I with multiloculated cystic lesions.</p> <p>Case presentation</p> <p>We report a case of type I CCAM presenting as a single, expansive cystic mass in the middle pulmonary lobe in a 38-year-old man, revealed by persistent cough and haemoptysis. Computed tomographic scan showed a single cyst with air fluid level, occupying the lateral segment of the lobe. When the type I CCAM is a single cyst, other cystic pulmonary lesions must be excluded. The intrapulmonary localization and the absence of cartilage in the cyst wall are conclusive findings of CCAM. The pathogenesis, management and differential diagnosis with other lung malformations are discussed along with a review of the literature.</p> <p>Conclusion</p> <p>The literature data confirm that surgical resection is the treatment of choice in all cases of CCAM and in the cases of cystic pulmonary lesions with uncertain radiological findings, in order to perform a histological examination of the lesion and to prevent infection and the potential neoplastic transformation.</p

Impact of governing modeson agrarian sustainability in Bulgaria

Abstract. Specific system of governance in different countries, regions, subsectors, etc., eventually determines the speed and type of socio-economic development. Despite its big academic and practical importance, in Bulgaria and other countries in East Europe, there are very few empirical studies on dominating governing structures in agriculture, and their impact(s) on agrarian sustainability. In this paper the interdisciplinary New Institutional Economics framework is incorporated, and the impact of diverse market, private, collective, public and hybrid modes of governance on agrarian sustainability at the current stage of development in Bulgaria assessed. First, the methodological framework of the study is outlined. After that dominating governing modes in Bulgarian farms of different juridical type, size, specialization, ecological and geographical location are identified, and their impacts on agrarian sustainability and its economic, social, and environmental pillars evaluated. In conclusion implications for further research, public policy improvement, and private managerial strategy formation are presented. Agricultural producers of different use quite unlike mixture of effective market, private, collective and hybrid modes for governance of their activities and relations. Individual factors and modes most contributing to improvement of agrarian sustainability at the current stage of development are: manager’s personal convictions and initiatives, farms resources and innovation potential, near future profit and benefits strategies, market prices levels and dynamics, area-based EU subsidies, and informal agreements. Research on relations between the governing structure and agrarian sustainability is to continue though increasing representation, and the spectrum of specific governing modes used by farms of different type as well as assessments of the impact of institutions on agrarian sustainability and the impact of the governance at different hierarchical levels. The latter however, requires a new kind of micro and macro data, and a close cooperation between all interested parties. Keywords. Agrarian Governance, Sustainability, Market, Private, Collective, Hybrid modes.JEL. Q13, Q12, Q18, D23, E61, H23, L14, L22, L33, L51

Parallel Program Composition with Paragraphs in Stapl

Languages and tools currently available for the development of parallel applications are difficult to learn and use. The Standard Template Adaptive Parallel Library (STAPL) is being developed to make it easier for programmers to implement a parallel application. STAPL is a parallel programming library for C++ that adopts the generic programming philosophy of the C++ Standard Template Library. STAPL provides collections of parallel algorithms (pAlgorithms) and containers (pContainers) that allow a developer to write their application without reimplementing the algorithms and data structures commonly used in parallel computing. pViews in STAPL are abstract data types that provide generic data access operations independently of the type of pContainer used to store the data. Algorithms and applications have a formal, high level representation in STAPL. A computation in STAPL is represented as a parallel task graph, which we call a PARAGRAPH. A PARAGRAPH contains a representation of the algorithm's input data, the operations that are used to transform individual data elements, and the ordering between the application of operations that transform the same data element. Just as programs are the result of a composition of algorithms, STAPL programs are the result of a composition of PARAGRAPHs. This dissertation develops the PARAGRAPH program representation and its compositional methods. PARAGRAPHs improve the developer's difficult situation by simplifying what she must specify when writing a parallel algorithm. The performance of the PARAGRAPH is evaluated using parallel generic algorithms, benchmarks from the NAS suite, and a nuclear particle transport application that has been written using STAPL. Our experiments were performed on Cray XT4 and Cray XE6 massively parallel systems and an IBM Power5 cluster, and show that scalable performance beyond 16,000 processors is possible using the PARAGRAPH

Informal Knowledge Networks: Toward a Community-Engineering Framework

The problems knowledge workers face today are dynamic, unstructured, highly complex, and often cannot be fully explicated. Such moving targets require different problem solving capabilities. Because abstract information is less valuable in this type of environment, knowledge workers have to utilize channels other than handbooks. Hence, corporate knowledge networks again are at the top of the research agenda. For a knowledge worker, access to knowledgeable colleagues, rather than access to large databases, becomes the important factor. In such networks, the question of which managerial actions are appropriate for successful community development ( i.e., supporting the actors) arises. Unfortunately, today’s community engineering practices are often characterized by a gross simplification and strong technological focus rather than modeling the impact of managerial actions before taking them. As part of a larger research project, this paper addresses topological structures as an action variable of community engineering. A computer-based simulation model is introduced and applied to real-life data from over 800 students and staff of the Economics and Business Administration Department at Frankfurt University, Germany

ABDOMEN ULTRASONOGRAPHIC EXAMINATION ANALYSIS IN THE CASE OF URINARY BLADDER DIVERTICULA AT CILEGON HOSPITAL: -

ABSTRACT Diverticulum is outpouching of hollow (or fluid-filled) structures, which can form in various organs in the body. Increased intravesical pressure (3-5 times) causes the bladder mucosa to infiltrate itself between the bladder muscle bundles which results in the development of extravasational sacs or saccules which subsequently results in diverticulum formation. The sonographic diagnosis of bladder diverticula depends on the demonstration of communication between the bladder and the mass. When such communication, or estuary, is not seen during ultrasound examination, the bladder diverticulum can look like any other type of cystic pelvic mass. The approach used is descriptive qualitative. This study aims to analyze the examination of the USG Abdomen with clinical bladder diverticula to get an appropriate picture of USG so that the diagnosis can be established. The study population was patients who performed an abdominal USG examination at the Cilegon Regional General Hospital. The sample of this study were 1 (one) patient. The method used in collecting data in this study is observation, documentation, and literature study. Keywords: Ultrasound, Urinary Bladder, Diverticul

Churchill regulates cell movement and mesoderm specification by repressing Nodal signaling

<p>Abstract</p> <p>Background</p> <p>Cell movements are essential to the determination of cell fates during development. The zinc-finger transcription factor, Churchill (ChCh) has been proposed to regulate cell fate by regulating cell movements during gastrulation in the chick. However, the mechanism of action of ChCh is not understood.</p> <p>Results</p> <p>We demonstrate that ChCh acts to repress the response to Nodal-related signals in zebrafish. When ChCh function is abrogated the expression of mesodermal markers is enhanced while ectodermal markers are expressed at decreased levels. In cell transplant assays, we observed that ChCh-deficient cells are more motile than wild-type cells. When placed in wild-type hosts, ChCh-deficient cells often leave the epiblast, migrate to the germ ring and are later found in mesodermal structures. We demonstrate that both movement of ChCh-compromised cells to the germ ring and acquisition of mesodermal character depend on the ability of the donor cells to respond to Nodal signals. Blocking Nodal signaling in the donor cells at the levels of Oep, Alk receptors or Fast1 inhibited migration to the germ ring and mesodermal fate change in the donor cells. We also detect additional unusual movements of transplanted ChCh-deficient cells which suggests that movement and acquisition of mesodermal character can be uncoupled. Finally, we demonstrate that ChCh is required to limit the transcriptional response to Nodal.</p> <p>Conclusion</p> <p>These data establish a broad role for ChCh in regulating both cell movement and Nodal signaling during early zebrafish development. We show that <it>chch </it>is required to limit mesodermal gene expression, inhibit Nodal-dependant movement of presumptive ectodermal cells and repress the transcriptional response to Nodal signaling. These findings reveal a dynamic role for <it>chch </it>in regulating cell movement and fate during early development.</p

Modeling geological objects with the XML Schema

Abstract Interchange, storage, and management of geological data require the development of knowledge-based, standardized vocabularies and data structures. Concepts modeled and designed with the Unified Markup Language (UML), can be mapped into XML Schema Definition Language (XSDL) to compose modular markup languages for each discipline. Developing such efficient, intra-disciplinary, modular and reusable components, based on the XSDL namespace facility and the principles of object-oriented design, reduces redundancy, increases efficiency, scalability, and extensibility, and simplifies the maintenance and future extension of the code. This paper discusses the best practices of composition and reuse of modular intra-disciplinary components by applying XML Schema namespace syntax. In addition to several small examples given for a variety of geological cases, the paper constructs a UML conceptual model and markup language, applying an XML-type library, for a component of the plate tectonics knowledge base (TectonicsML) that deals with the divergent plate boundary.

Session D7: Is CFD an Efficient Tool ao Develop Pool Type Fishways?

Abstract: Rivers longitudinal connectivity is compromised by man-made obstacles, such as dams and weirs, which affect fish movements, leading to populations decrease and genetic deterioration. Properly designed fishways re-establish connectivity, allowing for fish migration. The aim of our work is to contribute to a more fast and efficient development of pool-type fishways using hydrodynamic modelling, based on fish behaviour experiments. Modelling free surface flows in hydraulic structures with complex geometry, like pooltype fishways, with aerated and complex flow patterns, represents a significant research challenge. Knowledge already acquired in an experimental full scale indoor pool-type fishway in previous studies is used. A 1:2.5 scaled fishway of this facility was built and used to characterize velocity and turbulence in a pool-type fishway with cross-walls equipped with bottom orifices. An offset orifice configuration was used with consecutive orifices positioned on opposite sides of the cross-walls, creating a sinusoidal flow path. The measurements of velocity fields were made using Particle Image Velocimetry (PIV) and Acoustic Doppler Velocimetry (ADV). Velocity maps were obtained at several positions, for planes parallel to the bottom and parallel to the sidewalls. Parameters that influence fishways efficiency like velocity fields, turbulent kinetic energy and Reynolds shear stresses were determined. A 3D computational fluid dynamics (CFD) model of the fishway was developed using a commercial software FLOW-3D. Velocity fields, turbulent kinetic energy and Reynolds shear stresses were compared with the ones determined from PIV measurements and ADV measurements and results deviations between experimental and numerical data were analyzed. The use of FLOW 3D to simulate mean velocity patterns and flow turbulence in pooltype fishways and its use as design tool for new fishway geometries are discussed