Experimental investigation of systems for synchronizing time scales by means of the Quasar satellite communication system network

Experiments conducted at ground stations of the Quasar satellite communication network using both a null base as well as a base of around 2000 km is described. In experiments with a null base, the time scale transmission error was 1 nsec. Comparison of the results of collocation with data cbtained by the GLONASS system in the course of experiments using a 2100-km base demonstrated a divergence of the results of from 5 to 25 nsec. Translated from Izmeritel'naya Tekhnika, No. 4, pp. 35–38, April, 1996.     

Executing algorithms with hypercube topology on torusmulticomputers

Many parallel algorithms use hypercubes as the communication topology among their processes. When such algorithms are executed on hypercube multicomputers the communication cost is kept minimum since processes can be allocated to processors in such a way that only communication between neighbor processors is required. However, the scalability of hypercube multicomputers is constrained by the fact that the interconnection cost-per-node increases with the total number of nodes. From scalability point of view, meshes and toruses are more interesting classes of interconnection topologies. This paper focuses on the execution of algorithms with hypercube communication topology on multicomputers with mesh or torus interconnection topologies. The proposed approach is based on looking at different embeddings of hypercube graphs onto mesh or torus graphs. The paper concentrates on toruses since an already known embedding, which is called standard embedding, is optimal for meshes. In this paper, an embedding of hypercubes onto toruses of any given dimension is proposed. This novel embedding is called xor embedding. The paper presents a set of performance figures for both the standard and the xor embeddings and shows that the latter outperforms the former for any torus. In addition, it is proven that for a one-dimensional torus (a ring) the xor embedding is optimal in the sense that it minimizes the execution time of a class of parallel algorithms with hypercube topology. This class of algorithms is frequently found in real applications, such as FFT and some class of sorting algorithms     

Evaluating design metrics on large-scale software

Design-quality metrics that are being developed for predicting the potential quality and complexity of the system being developed are discussed. The goal of the metrics is to provide timely design information that can guide a developer in producing a higher quality product. The metrics were tested on projects developed in a university setting with client partners in industry. To further validate the metrics, they were applied to professionally developed systems to test their predictive qualities. The results of applying two design metrics and a composite metric to data from a large-scale industrial project are presented     

Maintaining global coherence during reading.

Previous research demonstrated a contradiction effect: Although text currently being processed was locally coherent, readers were aware of inconsistencies between a protagonist's actions and characteristics of the protagonists that were described earlier in the text and subsequently backgrounded. In the present experiments, not only the critical characteristics but also the protagonist were backgrounded. When the protagonist was reintroduced into the narrative in the context of carrying out an inconsistent action, the contradiction effect again occurred. In Exps 1–3, we examined the effects of several variables on the onset of the effect. In Exp 4, we presented probes at various points in the passage with results that supported the conclusion that the critical characteristics had been backgrounded before the sentence that contradicted them. Results are discussed in terms of several recent models in which currently active representational elements serve as retrieval cues for other inactive, but highly related, elements. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determining elasticity and strength characteristics of powder coating

Methods are described for forming coating specimens and testing them in pure bending. The proposed tester gives adequate accuracy in determining the elastic characteristics and strength for thin specimens (up to 0.1 mm) of brittle materials of powder-coating type.Translated from Problemy Prochnosti, No. 3, pp. 94–97, March, 1993.     

Fetal heart rate following coelocentesis

For psychological reasons, coelocentesis was performed in 20 women prior to termination of pregnancy, at 6-11 weeks of gestation. The fetal heart rate (FHR) was measured immediately before the procedure and at 1, 5, and 10 min afterward. There was no significant difference between FHR before coelocentesis compared to the values at 1 min (mean = 158, range 114-178; z = -0.629, P = 0.529), 5 min (mean = 160, range 121-179; z = -0.191, P = 0.848), or 10 min (mean 159, range 117-183; z = -0.214, P = 0.83) after the procedure. These findings suggest that coelocentesis does not have a major effect on the fetal cardiovascular system.     

Achieving synergy in collaborative education

Professional software engineering continues to face problems that involve large-scale (complex) software systems development. Such efforts typically require team collaboration over months, possibly years. Once implemented, the system must be maintained for sometimes decades. This development and maintenance life cycle requires not only technical knowledge and skills in software development, but also the knowledge and skills associated with software process. We believe the traditional computer science curriculum fails to consider this spectrum of needs. We also believe, however, that software engineering must use certain elements of the core knowledge and skills taught by computer scientists as its foundation. We describe lessons learned from the 10-year collaboration between Monmouth University and the Software Engineering Center of the US Army's CECOM (Communications Electronics Command). The center recruits electrical engineering and computer science graduates from academic institutions in the geographic regions surrounding its various installations to be part of its intern program; Monmouth University, in turn, incorporates the demands of the intern program in its Master of Science in software engineering curriculum     

Association of angiotensin-converting enzyme gene I/D polymorphism with change in left ventricular mass in response to physical training

PURPOSE: To determine the radiologic characteristics of cystic dystrophy of the duodenal wall. MATERIALS AND METHODS: Ten patients with cystic dystrophy of the duodenal wall and chronic pancreatitis underwent ultrasonography (US) (n = 10), computed tomography (CT) (n = 10), endoscopic US (n = 5), and endoscopic retrograde cholangiopancreatography (ERCP) (n = 9). Cystic dystrophy of the duodenal wall was classified as either cystic or solid. The imaging findings were retrospectively analyzed and compared with findings at pancreatoduodenectomy (n = 10). RESULTS: The more frequent cystic type (n = 7) of cystic dystrophy of the duodenal wall was characterized by the presence of easily recognizable cystic lesions (diameter, more than 1 cm), located within the thickened wall of the second portion of the duodenum. The solid type (n = 3) of cystic dystrophy of the duodenal wall demonstrated fibrous thickening of the duodenal wall within which small cysts (diameter, less than 1 cm) were present. The intraduodenal cysts were usually elongated or bilobate with a thick wall. The thickening of the duodenal wall appeared as a solid layer between the duodenal lumen and the pancreas, hypoechoic at US, isoattenuating at unenhanced CT, and hypoattenuating in the early phase (after initiation of infusion of contrast material) and isoattenuating in the late phase (after completion of infusion) at contrast material-enhanced CT. Findings at retrospective analysis of CT and endoscopic US images were characteristic. CONCLUSION: Imaging modalities, notably CT and endoscopic US, helped establish the diagnosis of cystic dystrophy of the duodenal wall.