193 research outputs found

    An Object-Oriented Language-Database Integration Model: The Composition-Filters Approach

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    This paper introduces a new model, based on so-called object-composition filters, that uniformly integrates database-like features into an object-oriented language. The focus is on providing persistent dynamic data structures, data sharing, transactions, multiple views and associative access, integrated with the object-oriented paradigm. The main contribution is that the database-like features are part of this new object-oriented model, and therefore, are uniformly integrated with object-oriented features such as data abstraction, encapsulation, message passing and inheritance. This approach eliminates the problems associated with existing systems such as lack of reusability and extensibility for database operations, the violation of encapsulation, the need to define specific types such as sets, and the incapability to support multiple views. The model is illustrated through the object-oriented language Sina

    A study on wear rates of 100Cr6 steel running against sintered steel surfaces under dry and starved lubrication

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    This paper investigates the tribological behavior of 100Cr6 steel pin running against sintered steel bearing material used in hermetic compressors. Tests were conducted under dry and starved lubrication sliding conditions in air at room temperature. Although porous structure acts as crack initiation sites thus limiting the wear resistance of sintered iron in dry sliding conditions under high contact stresses, it is believed to be beneficial in lubricated sliding conditions as it absorbs a large amount of lubricant. Wear tests without lubrication show that these pores are completely filled by abrasive particles in the initial stages of the test and no longer maintain their oil absorption capability. Initial results show that oxidation of frictional surfaces by flash temperature in dry conditions reduces weight loss volume by decreasing the coefficient of friction

    Antifungal and Bioherbicidal Properties of Essential Oils of Thymus fallax Fish & Mey., Origanum vulgare L. and Mentha dumetorum Schult.

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    WOS: 000343767000048The chemical composition of the essential oils obtained from the aerial parts of Thymus fallax, Origanum vulgare and Mentha dumetorum was analyzed by gas chromatography-mass spectrometry and the following were found to be the main constituents: T. fallax-thymol (41.48 %), o-cymene (26.75 %), zeta-terpinen (15.84 %), 2-isopropyl-1-methoxy-4-methylbenzene (5.10 %), terpineolene (2.11 %) and carvacrol (1.28 %); O. vulgare-thymol (50.41 %), carvacrol (12.96 %), 2-bornene (11.28 %), zeta-terpinen (8.80 %), o-cymene (6.68 %), alpha-bisabolane (2.19 %) and caryophyllene (1.31 %); and M. dumetorum-carvone (39.64 %), eucalyptol (14.34 %), dihydrocarvone (12.78 %), limonene (7.79 %). The antifungal activities of the oils against Alternaria solani, Fusarium oxysporum and Rhizoctonia solani were also evaluated and were found to be toxic to the pathogens. The results revealed that essential oils, especially those of T. fallax and O. vulgare, had a strong antifungal activity with a significant inhibition on the growth of the 3 tested fungi. In contrast, the M. dumetorum oil did not inhibit the growth of Rhizoctonia solani and also exerted a limited inhibitory effect on the mycelial growth of the other two fungi tested. The results of herbicidal assays using these essential oils against four different plant species, Abutilon theophrasti Medik., Agrostemma githago L., Medicago sativa L. and Lepidium sativum L., showed that the oils had inhibitory effects on seed germination and seedling growth. The findings of the present study confirmed that plant essential oils can be used as natural herbicides and fungicides to control weeds and pathogenic fungi, thus, reducing the dependence on synthetic pesticides

    Učinci liječenja fenetil esterom kavene kiseline na reumatološke pokazatelje i metabolizam željeza u štakorica s izazvanom šećernom bolešću.

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    Diabetology and rheumatology have much in common, including many biochemical features. Diabetic cases suffer excessively from common musculoskeletal conditions. The present study aimed to explore the association between the caffeic acid phenethyl ester (CAPE) treatment and the standard parameters of diabetic and rheumatologic controls. Serum anti-streptolysin-O (ASO), C-reactive protein (CRP), rheumatoid factor (RF) titers and glucose (GLU), cholesterol (CHOL), triglyceride (TG), high density lipoprotein (HDL), very low density lipoprotein (VLDL), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), sodium (Na), potassium (K), chloride (Cl), calcium (Ca), phosphorus (P), uric acid (UA), iron (Fe), iron-binding capacity (IBC), total iron-binding capacity (TIBC) and superoxide dismutase (SOD) levels were measured in 22 female Wistar-Albino rats. The animals were divided into three groups: group 1: non-diabetic rats as control; group 2: streptozotocin (STZ)-induced, untreated diabetic rats; and group 3: STZ-induced, CAPE-treated diabetic rats. Levels of GLU were increased in group 2. ASO values were decreased in group 3. TG and VLDL levels were increased in group 3 compared with the group 1. Higher UA levels were detected in group 3 compared with group 2. The levels of Fe and TIBC were decreased in group 3. The results of the present study indicate the reducing effect of CAPE on the serum levels of diabetic and rheumatologic parameters in diabetic rats.Dijabetologija i reumatologija imaju mnoge sličnosti, uključujući biokemijske procese. Oboljeli od dijabetesa pate od teških stanja mišićno-koštanog sustava. U ovom radu istražena je povezanost između liječenja fenetil esterom kavene kiseline i standardnih pokazatelja koji se kontroliraju pri dijabetičnim i reumatoidnim bolestima. Kod 22 Wistar-Albino štakorice mjereni su: serumski anti-streptolizin-O (ASO), C-reaktivni protein (CRP), titar reumatoidnog faktora (RF), zatim razina glukoze (GLU), kolesterola (CHOL), triglicerida (TG), lipoproteina visoke gustoće (HDL), lipoproteina vrlo niske gustoće (VLDL), alkalne fosfataze (ALP), gamaglutamil transferaze (GGT), natrija (Na), kalija (K), klorida (Cl), kalcija (Ca), fosfora (P), mokraćne kiseline (UA), željeza (Fe), kapaciteta vezanja željeza (IBC), ukupnog kapaciteta vezanja željeza (TIBC) i superoksid dismutaze (SOD). Životinje su bile podijeljene u tri skupine: 1. štakorice bez dijabetesa (kontrolna skupina), 2. neliječene štakorice s dijabetesom izazvanim streptozotocinom (STZ) i 3. štakorice sa streptozotocin (STZ) - izazvanim dijabetesom liječenim fenetil esterom kavene kiseline. Razine GLU bile su povećane u skupini 2. ASO vrijednosti bile su snižene u skupini 3. Razine TG i VLDL bile su povišene u skupini 3 u usporedbi s razinama u skupini 1. Više razine UA utvrđene su u skupini 3 u usporedbi sa skupinom 2. Razine Fe i TIBC bile su snižene u skupini 3. Rezultati pokazuju reducirajuće učinke fenetil estera kavene kiseline na razinu dijabetičnih i reumatoloških pokazatelja u serumu štakorica sa šećernom bolešću izazvanom streptozotocinom

    Tracking planar orientations of active MRI needles

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    Purpose: To determine and track the planar orientation of active interventional devices without using localizing RF microcoils. Materials and Methods: An image-based tracking method that determines a device's orientation using projection images was developed. An automated and a manual detection scheme were implemented. The method was demonstrated in an in vivo mesocaval puncture procedure in swine, which required accurate orientation of an active transvascular needle catheter. Results: The plane of the catheter was determined using two projection images. The scan plane was adjusted automatically to follow the catheter plane, and its orientation with respect to a previously acquired target plane was displayed. The algorithm facilitated navigation for a fast and accurate puncture. Conclusion: Using image-based techniques, with no mechanical design changes, the orientation of an active intravascular probe could be tracked. © 2007 Wiley-Liss, Inc

    Metameric Inpainting for Image Warping

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    Image-warping , a per-pixel deformation of one image into another, is an essential component in immersive visual experiences such as virtual reality or augmented reality. The primary issue with image warping is disocclusions, where occluded (and hence unknown) parts of the input image would be required to compose the output image. We introduce a new image warping method, Metameric image inpainting - an approach for hole-filling in real-time with foundations in human visual perception. Our method estimates image feature statistics of disoccluded regions from their neighbours. These statistics are inpainted and used to synthesise visuals in real-time that are less noticeable to study participants, particularly in peripheral vision. Our method offers speed improvements over the standard structured image inpainting methods while improving realism over colour-based inpainting such as push-pull. Hence, our work paves the way towards future applications such as depth image-based rendering, 6-DoF 360 rendering, and remote render-streaming

    Vaccination coverage and reasons for non-vaccination in a district of Istanbul

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    BACKGROUND: In order to control and eliminate the vaccine preventable diseases it is important to know the vaccination coverage and reasons for non-vaccination. The primary objective of this study was to determine the complete vaccination rate; the reasons for non-vaccination and the predictors that influence vaccination of children. The other objective was to determine coverage of measles vaccination of the Measles Immunization Days (MID) 2005 for children aged 9 month to 6 years in a region of Umraniye, Istanbul, Turkey. METHODS: A '30 × 7' cluster sampling design was used as the sampling method. Thirty streets were selected at random from study area. Survey data were collected by a questionnaire which was applied face to face to parents of 221 children. A Chi-square test and logistic regression was used for the statistical analyses. Content analysis method was used to evaluate the open-ended questions. RESULTS: The complete vaccination rate for study population was 84.5% and 3.2% of all children were totally non-vaccinated. The siblings of non-vaccinated children were also non-vaccinated. Reasons for non-vaccination were as follows: being in the village and couldn't reach to health care services; having no knowledge about vaccination; the father of child didn't allow vaccination; intercurrent illness of child during vaccination time; missed opportunities like not to shave off a vial for only one child. In logistic regression analysis, paternal and maternal levels of education and immigration time of both parents to Istanbul were found to influence whether children were completely vaccinated or non-vaccinated. Measles vaccination coverage during MID was 79.3%. CONCLUSION: Efforts to increase vaccination coverage should take reasons for non-vaccination into account

    Perceptually guided computer-generated holography

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    Computer-Generated Holography (CGH) promises to deliver genuine, high-quality visuals at any depth. We argue that combining CGH and perceptually guided graphics can soon lead to practical holographic display systems that deliver perceptually realistic images. We propose a new CGH method called metameric varifocal holograms. Our CGH method generates images only at a user’s focus plane while displayed images are statistically correct and indistinguishable from actual targets across peripheral vision (metamers). Thus, a user observing our holograms is set to perceive a high quality visual at their gaze location. At the same time, the integrity of the image follows a statistically correct trend in the remaining peripheral parts. We demonstrate our differentiable CGH optimization pipeline on modern GPUs, and we support our findings with a display prototype. Our method will pave the way towards realistic visuals free from classical CGH problems, such as speckle noise or poor visual quality

    Light engine and optics for HELIUM3D auto-stereoscopic laser scanning display

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    This paper presents a laser based auto-stereoscopic 3D display technique and a prototype utilizing a dual projector light engine. The solution described is able to form dynamic exit pupils under the control of a multi-user head-tracker. A prototype completed recently is able to provide a glasses-free solution for a single user at a fixed position. At the end of the prototyping phase it is expected to enable a multiple user interface with an integration of the pupil tracker and the spatial light modulator
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