4,057 research outputs found
On the Capacity Region of the Deterministic Y-Channel with Common and Private Messages
In multi user Gaussian relay networks, it is desirable to transmit private
information to each user as well as common information to all of them. However,
the capacity region of such networks with both kinds of information is not easy
to characterize. The prior art used simple linear deterministic models in order
to approximate the capacities of these Gaussian networks. This paper discusses
the capacity region of the deterministic Y-channel with private and common
messages. In this channel, each user aims at delivering two private messages to
the other two users in addition to a common message directed towards both of
them. As there is no direct link between the users, all messages must pass
through an intermediate relay. We present outer-bounds on the rate region using
genie aided and cut-set bounds. Then, we develop a greedy scheme to define an
achievable region and show that at a certain number of levels at the relay, our
achievable region coincides with the upper bound. Finally, we argue that these
bounds for this setup are not sufficient to characterize the capacity region.Comment: 4 figures, 7 page
AMPLITUDE-VERSUS-ANGLE ANALYSIS AND WIDE-ANGLE-INVERSION OF CROSSWELL SEISMIC DATA IN A CARBONATE RESERVOIR
Crosswell data set contains a range of angles limited only by the geometry of the source and receiver configuration, the separation of the boreholes and the depth to the target. However, the wide angles reflections present in crosswell imaging result in amplitude-versus-angle (AVA) features not usually observed in surface data. These features include reflections from angles that are near critical and beyond critical for many of the interfaces; some of these reflections are visible only for a small range of angles, presumably near their critical angle.
High-resolution crosswell seismic surveys were conducted over a Silurian (Niagaran) reef at two fields in northern Michigan, Springdale and Coldspring. The Springdale wells extended to much greater depths than the reef, and imaging was conducted from above and from beneath the reef. Combining the results from images obtained from above with those from beneath provides additional information, by exhibiting ranges of angles that are different for the two images, especially for reflectors at shallow depths, and second, by providing additional constraints on the solutions for Zoeppritz equations.
Inversion of seismic data for impedance has become a standard part of the workflow for quantitative reservoir characterization. Inversion of crosswell data using either deterministic or geostatistical methods can lead to poor results with phase change beyond the critical angle, however, the simultaneous pre-stack inversion of partial angle stacks may be best conducted with restrictions to angles less than critical.
Deterministic inversion is designed to yield only a single model of elastic properties (best-fit), while the geostatistical inversion produces multiple models (realizations) of elastic properties, lithology and reservoir properties. Geostatistical inversion produces results with far more detail than deterministic inversion. The magnitude of difference in details between both types of inversion becomes increasingly pronounced for thinner reservoirs, particularly those beyond the vertical resolution of the seismic.
For any interface imaged from above and from beneath, the results AVA characters must result from identical contrasts in elastic properties in the two sets of images, albeit in reverse order. An inversion approach to handle both datasets simultaneously, at pre-critical angles, is demonstrated in this work.
The main exploration problem for carbonate reefs is determining the porosity distribution. Images of elastic properties, obtained from deterministic and geostatistical simultaneous inversion of a high-resolution crosswell seismic survey were used to obtain the internal structure and reservoir properties (porosity) of Niagaran Michigan reef. The images obtained are the best of any Niagaran pinnacle reef to date
Effects of Genotype, Season and Nutrition on Sunflower Yield and Hollow Seededness in Gezira (Sudan)
A field experiment was conducted to study the effects of genotype, season and nutrition on sunflower seed yield and hollow seededness in Gezira. Five sunflower cultivars (Damazin-l, Hungarian-A, Rodio, Hysun-25 and Hysun-33), two nitrogen levels (0 and 129 kgN/ha) and two levels of phosphorus (0 and 129 kg P205/ha) were used over two seasons (autumn and winter 2000) in a randomized complete block design with four replications. Data on 14 characters were collected. results showed that the percentage of empty seeds, self-compatibility 1000-seed weight and seed yield were significantly affected by and its interaction with season. The means of these characters were relatively higher in winter than in autumn season except for the empty seeds. The application of high doses of fertilizer had no significant effect on the percentage of empty seeds, and consequently lie phenomenon of empty seeds could be attributed mainly to genetical and seasonal effects. The genotypes mean seed yields ranged from 1127 to 1899 kg/ha, with Hysun-33 giving the highest yield. Simple and genotypic correlation analyses emphasized that seed yield was and positively correlated with days to flowering, harvest index , head diameter, seed number/head, self-compatibility, number filled seeds/head and percent seed set. Both analyses showed negative coefficients between seed yield and empty seeds. The percentage of empty seeds was positively and significantly correlated with plant height and number of heads/plant. The path analysis indicated that head diameter, percentage of seed set, days to flowering and seed weight were the most important traits related to seed yield where as percentage of seed set, harvest index, and days to maturity were the most important traits contributing to high degree of self-compatibility in sunflow
Correlation Between the Total Small Bowel Length and Anthropometric Measures in Living Humans : Cross-Sectional Study
Open Access via Springer Compact AgreementPeer reviewedPublisher PD
Combining ability analysis for seed yield and its components in sesame
Sesame (Sesamum indicum L.) experiments, were carried out in central Sudan during the rainy season of 2009 at two locations (Abu Naama and Sinnar). The hybridization plan consisted of seven male and seven female parents giving 49 crosses following line x tester arrangement. Treatments were arranged in a randomized complete block design with three replicates. The crosses and their parents were sown on the 7th of July for all the experiments at both locations. The traits measured were days to 50% flowering, days to maturity, plant height, number of capsules per plant, number of seeds per capsule, capsule length, 1000-seed weight and seed yield. Analysis of variance revealed that genetic variability was highly significant for all the characters studied at both locations and across them. Combining ability analysis showed that additive gene effects were important for inheritance of days to 50% flowering, plant height, number of capsules/plant, number of seeds per capsule, capsule length, 1000-seed weight, days to maturity and seed yield, whereas non-additive gene effects were important for number of seeds/capsule, indicating that the inheritance of this trait is due to specific combining ability (SCA). Combining ability analysis showed that parents, L7, L5, T2, T5 and T6 were good combiners for high seed yield as well as for most of the other traits measured in this study. Assessment of SCA effects for seed yield at Abu-Namma revealed that hybrid T4 x L4 had a maximum positive SCA effect and a high per se performance followed by T2 x L2, T5 x L5 and T6 x L3, while at Sinnar T6 x L6 had the highest positive SCA effects followed by T6 xL3, T1 x L5 and T2 x L6. However T6 x L3, T1 x L5, T4 x L2 and T2 x L1 exhibited the highest SCA effects across sites. The present study suggested hybrids T6 x L3, T1 x L5 and T4 x L2 to be tested in multi-location trials for commercial utilization, while, parents L7, L5, T2 and T6 can be used in recurrent selection.
أجريت هذه التجارب في السودان أثناء الفصل الممطر عام 2009 في أبو نعامة وسنار بإتباع تحليل سلالة x مختبر line x tester analysis)) والذي شمل سبعة آباء ذكورmale parents)) وسبعة أباء اناث (female parents) معطية 49 هجيناً. أستخدم تصميم القطاعات العشوائية الكاملة بثلاث مكررات. زرعت التجارب في يوم 7 يوليو 2009 في كلا الموقعين. الصفات التي تمت دراستها شملت عدد الأيام حتى 50% إزهار، عدد الأيام حتى النضج، طول النبات، عدد الكبسولات في النبات، عدد البذور في الكبسولة، طول الكبسولة، وزن 1000 بذرة وإنتاجية البذور. أظهر تحليل التباين وجود فروق معنوية لكل الصفات المدروسة في الموقعين. أظهر تحليل القدرة علي التالف أن تأثيرات الفعل الإضافي للجين كانت أهم لتوريث صفات عدد الأيام حتى 50% إزهار، طول النبات، ارتفاع أول كبسولة، ارتفاع أول فرع، عدد الفروع في النبات، عدد الكبسولات في النبات، طول الكبسولة، عدد الأيام حتى النضج، وزن 1000 بذرة و إنتاجية البذور كما كانت تأثيرات الفعل الجيني غير الإضافي مهمة في توريث صفة عدد البذور في الكبسولة وهذه النتيجة تشير بان السيادة وتفاعلات التفوق تتحكم في تلك الصفة. أظهرت تأثيرات القدرة العامة للاتحاد إن الآباء L7 T5, T2, L5,و T6كانت الأفضل قدرة على الاتحاد لإنتاج البذور بالإضافة لأغلب الصفات الأخرى في التحليل المشترك. الهجن التي أظهرت أعلى قوة هجين في أبونعامة T5 x L5, T2 x L2, T4 x L4 وT6 x L3 ، بينما في سنار T6 x L6, T6 x L3, T2 x L6 و T1 x L5وعبر الموقعين T6 x L3, T1 x L5, ,T4xL2 وT2 x L1. وجد أن هناك ارتباطاً موجباً لإنتاجية البذور لكل من وزن 1000 بذرة ، عدد الكبسولات في النبات وعدد الأيام حتى النضج. اقترحت الدراسة الحالية إن الهجنT1 x L5, T6 x L3 وT6 x L7 لإنتاج البذور أما الآباء T4، T1 ، L6و T6 فيمكن استخدامهم في التهجين الرجع
Vegetative description of three Aquilaria (Thymelaeaceae) saplings in Malaysia
Plants` reproductive parts are most important for species identification. However, trees such as Aquilaria species take many years to mature and produce flowers and fruits. Inconsistent and infrequent flowering periods may cause additional hindrance to classical identification. In this study, descriptions were made based on vegetative parts such as leaf, branch and bark for saplings of three Aquilaria species found in Malaysia. It was found that A. hirta sapling can be recognized through the densely hairy twigs, young shoots and axillary buds, undersurface of leaf, margin, petiole and midrib besides the strongly raised midrib, and usually unbranched habit; A. malaccensis through the many branches and white spots along main axis, entire leaf margin, slightly hairy leaf undersurface and midrib, and glabrous petiole; Aquilaria sp.1 from the lower branches that are nearly perpendicular to the stem and wavy leaf margin. These vegetative characters can serve as a basis for the correct identification of Aquilaria saplings when growers need to confirm their planting materials
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