64 research outputs found
Architecture conformance analysis approach within the context of multiple product line engineering
One of the important concerns in software product line engineering is the conformance of the application architecture to the product line architecture. Consistency with the product line architecture is important to ensure that the business rules and constraints that are defined for the entire product family are not violated. Usually, the conformance checking to the product line architecture is a manual and tedious process. A popular approach for ensuring architecture conformance is reflexion modeling which has been primarily used to check the consistency between the architecture and the code. In this paper we present an approach for product line conformance analysis based on reflexion modeling. We consider conformance analysis in product line engineering and extend our discussion to multiple product line engineering. Our study shows several important challenges regarding reflexion modeling within the context of product line engineering. © 2014 IEEE
Optimization of F2 layer parameters using IRI-Plas model and IONOLAB Total Electron Content
In this study, the relation of the maximum ionization height (HmF2) and the critical frequency (FoF2) of F2 layer is examined within their parametric range through the International Reference Ionosphere extended towards the plasmasphere (IRI-Plas) model and the IONOLAB-TEC (Total Electron Content) observations. HmF2 and FoF2 are optimized using an iterational loop through Non-Linear Least Squares method by also using a physical relation constraint between these two parameters. Performance evaluation of optimization algorithm is performed separately for the cases running IRI-Plas with optimized parameters and TEC input; only with optimized parameters; only with TEC and finally with no optimized parameter and TEC input. As a conclusion, it is seen that using optimized parameters and TEC together as input produces best IRI-TEC estimates. But also using only optimized parameters (without TEC update) gives estimates with also very low RMS errors and is suitable to use in optimizations. HmF2 and FoF2 estimates are obtained separately for a quiet day, positively corrupted day, negatively corrupted day, a northern latitude and a southern latitude. HmF2 and FoF2 estimation results are compared with ionosonde data where available. This study enables the modification and update of empirical and deterministic IRI Model to include instantaneous variability of the ionosphere. © 2011 IEEE
Space-time interpolation and automatic mapping of TEC using TNPGN-active
Turkish National Permanent GPS Network (TNPGN) is the Reference Station Network of 146 continuously-operating GNSS stations o which are distributed uniformly across Turkey and North Cyprus Turkish Republic since May 2009. IONOLAB group, formed by researchers and students in Hacettepe University, Bilkent University and General Command of Mapping is currently investigating new techniques for space-time interpolation, and automatic mapping of TEC through a TUBITAK research grant. This study presents the developments in monitoring of space weather, and correction of geodetic positioning errors due to ionosphere using TNPGN. © 2011 IEEE
Space weather activities of IONOLAB group using TNPGN GPS Network
Characterization and constant monitoring of variability of the ionosphere is of utmost importance for the performance improvement of HF communication, Satellite communication, navigation and guidance systems, Low Earth Orbit (LEO) satellite systems, Space Craft exit and entry into the atmosphere and space weather. Turkish National Permanent GPS Network (TNPGN) is the Reference Station Network of 146 continuously-operating GNSS stations of which are distributed uniformly across Turkey and North Cyprus Turkish Republic since May 2009. IONOLAB group is currently investigating new techniques for space-time interpolation, and automatic mapping of TEC through a TUBITAK research grant. It is utmost importance to develop regional stochastic models for correction of ionospheric delay in geodetic systems and also form a scientific basis for communication link characterization. This study is a brief summary of the efforts of IONOLAB group in monitoring of space weather, and correction of geodetic positioning errors due to ionosphere using TNPGN. © 2011 IEEE
ConSpec – a formal language for policy specification 1
The paper presents ConSpec, an automata based policy specification language. The language trades off clean semantics to language expressiveness; a formal semantics for the language is provided as security automata. ConSpec specifications can be used at different stages of the application lifecycle, rendering possible the formalization of various policy enforcement techniques.
Supporting Incremental Product Development using Multiple Product Line Architecture
Software product line engineering (SPLE) has been successfully applied in various application domains to support systematic reuse. Besides of its benefits it is also acknowledged that the SPLE process can in practice be considered too time consuming and heavyweight due to the required planning and development of the asset base. For this reason more lightweight SPLE processes are required that can be integrated in the ongoing product development of the organization. In this context, the authors share their experiences in adopting a multiple product line architecture to support the incremental product development of Aselsan REHIS, a leading high technology company in Turkey. The authors first discuss the important business needs for defining a more lightweight multiple product line engineering (MPLE) process. Then they discuss the multiple product line architecture and how it has been used to guide the incremental product development
Laparoscopic appendectomy in children performed using single endoscopic GIA stapler for both mesoappendix and base of appendix
Background/Purpose: Similar to open appendectomy (OA), most of the methods described for laparoscopic appendectomy (LA) require two steps: (1) dissection and division of mesoappendix and (2) excision of appendix. Dissection of mesoappendix requires more skill and experience during LA. In single endoscopic GIA stapler laparoscopic appendectomy technique (SESLAT), both mesoappendix and base of appendix may be divided in one step with the application of a single endoscopic GIA stapler
Slip rates and locking depth variation along central and easternmost segments of North Anatolian Fault
International audienceWhile the kinematics of Anatolia plate and the North Anatolian Fault System (NAFS) has been studied extensively, the slip rate and locking depth along the NAFS are usually assumed constant in the analyses due to the lack of sufficient data. This is also partly due to the reasonably good fit of Euler small circle and partly due to the lack of spatial resolution of observations to determine slip rates independently from locking depths. On the other hand, recent geodetic studies show a contrast for locking depth between Marmara and other parts of the NAFS, implying a non-uniform locking depth across the NAFS. In this study, we analyse new GPS data and homogenously combine available data sets covering the eastern part of the NAFS to form the most complete data set. In particular, we incorporate the first results of Turkish Real-Time Kinematic GPS Network (CORS-TR) into our data set. A detailed analysis of three profiles within the NAFS reveals an increase of locking depth in the middle profile to 19.1 ± 3.4 km from 11.9 ± 3.5 km in the easternmost profile while the slip rate is nearly constant (20–22 mm yr−1), which implies a variation of strain rate of ∼100 nanostrain yr−1. Assuming a constant locking depth throughout whole NAFS gives an average locking depth of 14.3 ± 1.7 km. Our best estimates of slip rates in block modelling which takes the variation of locking depths into account are in the range between 22.5 and 22.8 mm yr−1 over eastern part of the NAFS
Immunohistochemical expression of connexin 43 and occludin in the rat testis after epididymal and vasal ligation
PubMed ID: 17825302Objective: To describe the effects of epididymal and vasal ligation, in an experimental rat model, by using connexin 43 and occludin immunohistochemistry as well as transmission electron microscopy. Design: Comparative and controlled experimental research study. Setting: University animal research and histology laboratories in Turkey. Animal(s): Wistar male rats in experimental and control groups. Intervention(s): The control group underwent sham operation (n = 7). The first experimental group (n = 7) underwent unilateral epididymal ligation, whereas the second experimental group (n = 7) underwent unilateral vasal ligation to induce experimental epididymal and vasal obstruction models, respectively. All animals were then killed at 90 days. Main Outcome Measure(s): Immunohistochemical expression of connexin 43 and occludin for testicular tissues was determined after epididymal and vasal obstruction models. Ultrastructural morphological changes were examined by electron microscopy. Result(s): Results of the semiquantitative analysis revealed that expressions of both occludin and connexin 43 in the rat testis were decreased in the experimental groups compared with in the sham-operated group. However, changes after vasal ligation were more prominent. Ultrastructural examination confirmed decreased intercellular communication as well as increased cellular degeneration among the ipsilateral and contralateral testicular tissues. Conclusion(s): Immunohistochemical expression of occludin and connexin 43 were decreased in the testis after vasal and epididymal ligation when compared with the sham-operated group. Ultrastructural changes indicating cell degeneration were more prominent after vasal ligation. © 2008 American Society for Reproductive Medicine.Ege ÜniversitesiThe study protocol was approved by the Institutional Animal Care and Use Committee in accordance with US National Institutes of Health policy and Ege University policy. -
- …