High Success Ratio Research Articles

Distributed multicast routing for delay and delay variation-bounded Steiner tree using simulated annealing

The delay and delay variation-bounded Steiner tree problem is an important multicast routing issue in real-time multimedia networks. Such a constrained Steiner tree problem is known to be NP-complete. In this paper, we propose a distributed multicast routing algorithm based on simulated annealing to produce routing trees having a minimal network cost under delay and delay variation constraints. The proposed algorithm is fully distributed, and supports the dynamic reorganizing of the multicast tree in response to changes for the destination. Simulations demonstrate that our algorithm is better in terms of tree cost as compared with other existing algorithms, and it performs excellently in delay and delay variation. Furthermore, it has high success ratio, rapid convergence and better real-time property.

Prediction and dimension

Given a set X of sequences over a finite alphabet, we investigate the following three quantities. (i) The feasible predictability of X is the highest success ratio that a polynomial-time randomized predictor can achieve on all sequences in X. (ii) The deterministic feasible predictability of X is the highest success ratio that a polynomial-time deterministic predictor can achieve on all sequences in X. (iii) The feasible dimension of X is the polynomial-time effectivization of the classical Hausdorff dimension (“fractal dimension”) of X. Predictability is known to be stable in the sense that the feasible predictability of X ∪ Y is always the minimum of the feasible predictabilities of X and Y. We show that deterministic predictability also has this property if X and Y are computably presentable. We show that deterministic predictability coincides with predictability on singleton sets. Our main theorem states that the feasible dimension of X is bounded above by the maximum entropy of the predictability of X and bounded below by the segmented self-information of the predictability of X, and that these bounds are tight.

NONSYMMETRIC TWO-BODY SCORE FUNCTION FOR PROTEIN FOLD RECOGNITION: NEXT NEAREST NEIGHBOR-ADJACENCY OF TWO AMINO ACIDS

The usual two-body score (energy) function to recognize native folds of proteins is Miyazawa–Jernigan (MJ) pairwise-contact function. The pairwise-contact parameters between two amino acids in MJ function are symmetric in a sense that a directional order of amino acids sequence along the backbone of a protein is ignored in constructing score parameters. Here we report that we succeeded in constructing a nonsymmetric two-body score function, capturing a directional order of amino acids sequence, by a perceptron learning and a protein threading. We considered pairs of two adjacent amino acids that are separated by two consecutive peptide bonds with the backbone directionality from the N-terminus to the C-terminus of a protein. We also considered the local environmental character, such as the secondary structures and the hydrophobicity (solvation), of amino acids in protein structures. The score is a corresponding propensity for a directional alignment of these two adjacent amino acids with their local environments. The resulting score function simultaneously recognized native folds of 1006 proteins covering all representative proteins with a homology less than 30% among them. The quality of this score function was validated by a threading test of new distinct 382 proteins with a homology less than 90% among them, and it entailed a high success ratio for recognizing native folds of 364 (95.3%) proteins. It showed a good feasibility of designing protein score functions for protein fold recognition by a perceptron learning and a protein threading.

A practical method for uniaxial tension test of concrete

A test method for uniaxial tension test of concrete to obtain tension softening curves has not been established yet, because there are several difficulties in performing the test. In the past 40 years, many different test conditions, sometimes even completely opposite conditions have been adopted. In order to show which conditions should be selected and why the conditions should be selected, theoretical and experimental investigation was carried out. For the experiment, prismatic specimens with notches and an originally designed gear system preventing secondary flexure were adopted. It was shown that the tension softening curves were successfully monitored by the present procedure with a high success ratio. A practical test procedure of uniaxial tension test of concrete was proposed based on the investigation.

Multiple additively constrained path selection

Finding a feasible path subject to multiple constraints in a network is an NP-complete problem and has been extensively studied. However, current algorithms suffer either high computational complexity or low success ratio in finding feasible paths. The authors propose a novel extended Bellman–Ford algorithm (EB), from which they present a high-performance algorithm with low computational complexity in finding feasible paths with multiple additive constraints. Through analysis and simulations, it is shown that the algorithm outperforms its contenders in the success rate of finding a feasible path as well as in terms of scalability; the proposed algorithm can achieve almost 100% success ratio as long as a feasible path exists. Furthermore, the worst case computational complexity is only twice that of the Bellman–Ford algorithm.

QMBF: a QoS-aware multicast routing protocol

Many multicast applications, such as video-on-demand and tele-education, desire quality of service (QoS) support from the underlying network. Recently, many QoS-based multicast protocols have been proposed to meet this requirement. However, few of them can achieve high success ratios while maintaining good scalability. In this paper, we propose a new QoS-aware multicast protocol based on a bounded flooding technique (QMBF). In this protocol, every network node maintains the knowledge of a local network cell (LNC) topology as well as QoS state information (collected from the bounded flooding messages). QMBF utilizes this knowledge to increase the probability and accuracy of finding a feasible branch which connects a new member to an existing multicast tree. The protocol exploits two approaches to find feasible branches: repeatedly computing partial feasible branches using the LNC information and searching multiple paths. The design of QMBF allows it to operate on top of any unicast routing protocol or cooperate with a QoS-based unicast routing protocol. Results obtained using NS-2 simulator demonstrate high success ratio for locating feasible branches for multicast paths.

Success and Gender: Determining the Rate of Advancement for Intercollegiate Athletic Directors

Since the demise of the Association for Intercollegiate Athletics for Women (AIAW), female sport administrators have continued their struggle to reestablish their place as athletic directors. The purpose of this study was to assess the rate of advancement (success ratio) of intercollegiate athletic directors, with a primary focus on gender. Athletic directors from 157 NCAA (National Collegiate Athletics Association) member institutions participated in the study. The preliminary results confirmed the expected findings that hegemonic masculinity was entrenched within intercollegiate athletics. The success ratio of male athletic directors differed from that of female athletic directors, and the difference was significant (p ≤ .05). The success ratio for men was higher than the ratio for women. Further analyses, however, showed that female athletic directors had higher success ratios than their male peers at lower level institutions. Although parity in numbers has not yet been achieved across the NCAA, the glass ceiling at Division I institutions may begin to crack as more women achieve success at the lower level institutions.

Predicting merger targets of hospitality firms (a Logit model)

The study investigates differentiating characteristics of merger target firms in the hospitality industry. A Binomial Logit Analysis Model to predict merger targets is developed and empirically estimated. Among nine company attributes which are hypothesized to be important factors in predicting merger targets, four are found to be significant. Back-testing of the model’s ability to correctly predict merger targets shows a high success ratio with statistically significant results at the usually accepted level. This suggests that a formal model like this can be used by practitioners as a supplementary decision-supporting tool for identifying companies with a high likelihood of being merger targets.

Blanket 3-D Coverage-Its Successful Application in Exploring a Mature Area, Central Dutch Offshore

In the K and L blocks of the Dutch sector of the southern North Sea, the Rotliegende Sandstone forms the main objective. Drilling started in 1968, and to date 36 Rotliegende gas fields have been discovered in Nederlandse Aardolie Maatschappij (NAM) operated acreage with volumes in place ranging between 2 and 50 x 10[sup 9]m[sup 3]. Approximately 70% of these fields were discovered using two-dimensional seismic, but as exploration progressed an increasing number of wells were found water bearing. The main cause of failure is lack of structural integrity, due to high Rotliegende fault density and highly variable overburden dominated by Zechstein salt and Chalk grabens. Three-dimensional (3-D) seismic acquisition started in 1981 but at first was typically limited to small production surveys covering existing gas fields. In 1986, acquisition of block-wide exploration 3-D surveys began. This has resulted in a present-day coverage of some 5000 km[sup 2], representing 95% of NAM-operated central offshore K and L blocks. Interpretation of these surveys revealed many undrilled structures, inspiring a second phase of exploration drilling with a high success ratio of 80%. As drilling activity progressed in the earliest covered blocks, however, a number of structurally conclusive dry wells were drilled, andmore » remaining individual prospects are small. Therefore, a third exploration phase now has started, concentrating on hydrocarbon habitat reviews making use of detailed 3-D interpretation of seismic attributes. The reconstruction of tectonic history and and updated charge model are expected to lead to an improved definition of remaining potential in these mature blocks.« less

Application of pattern recognition algorithm in the seismic belts of Indian convergent plate margin — CN algorithm

The earthquake catalogue from 1964 to August 1991 is used to identify the times of increased probabilities (TIPs) of the earthquake mainshocks of magnitudes greater than or equal to 6·4 and are associated with the Indian convergent plate margins, in retrospect. In Pakistan and Indo-Burma regions, the analysis was repeated for magnitude threshold 6·2 and 7·0 respectively. All the earthquakes (except one in the Hindukush region and one in Indo-Burmese region) in Pakistan, Hindukush-Pamir, Himalaya and Indo-Burmese regions were preceded by the special activation and hence were predicted.Approximately 23 ± 10% of the total time (1970 to August 1991) is occupied by the TIPs in all the regions. The reasons for failure to predict the two earthquakes in these regions are discussed.Our analysis gives a better picture of the regionalization and the size of the space-time volume for the preparation of an earthquake. The high success ratio of the algorithm proves that it can be applied in this territory for further prediction in the real time, without any significant changes in its parameters.

Comparison of reliability of conventional and rapid aging methods for insulating materials

It is shown that the conventional aging (CA) method of insulating materials is only an approximation, and simulates the actual service of insulation. Since the test is complex and uncertain, CA cannot be absolute. Although most rapid thermal endurance test methods of insulating materials are based on CA, once established, they are independent test methods. Further, the dispersion of CA data is large and repeating the tests is difficult due to its long time and high costs. Rapid methods, such as thermogravimetric point slope (TPS), have smaller scatter, higher success ratio, and good accuracy and are easy to repeat. Therefore, taken as a whole, the reliability of TPS may well be identical with, or even better than, that of CA for determining the thermal endurance properties of insulating materials. >

Geology of Abo Gas-Producing Areas of Pecos Slope, Chaves County, New Mexico: ABSTRACT

The discovery of Abo gas production from continental Permian red beds in north-central Chaves County, New Mexico, resulted in a flurry of drilling activity. Yates Petroleum Corp. reentered the Honolulu 1 McConkey, an Ellenburger dry hole, and completed it from Abo perforations for an initial potential of 2,551 mcf of gas per day and 1 bbl of condensate per day. Although this discovery was completed in September 1977, drilling continued at a slow pace until federal regulations designated the Abo formation as tight gas sands, in 1980. This stimulated drilling activity to the extent that, as of August 1983, almost 850 wells had been drilled, with a high success ratio. Lee named the Abo formation for sandstone exposures in Abo Canyon, at the south end of the Manzano Mountains, southeast of Albuquerque. Needham and Bates re-described the Abo and named a type section for exposures in Socorro and Torrance Counties and considered it to be of continental origin because of cross-bedding, plant remains, and other characteristics. The Abo is generally believed to be Wolfcampian in age; however, in a few areas the upper portion of the Abo is Leonardian. This is based partly on fossils and also on the fact that the Abo in places grades into the overlying Yeso. The Pedernal landmass, situated to the north and west of the Pecos slope area, provided most of the sediments as siltstones, sandstones, mudstones, and shales. The sandstones are characteristically arkosic in most areas. These Abo sediments were deposited under fluvial-deltaic conditions. End_of_Article - Last_Page 119------------

Shallow seismic investigation for location and evaluation of groundwater reserves in the weathered mantles of the Basement Complex in southwestern Nigeria

This study revealed that the groundwater zones in the weathered mantles in the Basement Complex of southwestern Nigeria can be reliably located by the seismic refraction method. The water table and the weathering front were each detected as a distinct refracting horizon. A seismic velocity range of 820–1060 m/s was observed in the unsaturated weathered material above the water table. The zone of saturation has a velocity range of 1550–1740 m/s, while in the underlying weathering country-rocks the range is from 2840 to 3160 m/s. The depth to water table, the saturated zone thickness and the absolute depth of weathering were seismically determined with a high level of precision. The data acquired were statistically analyzed to establish the major geohydrological characteristics of the regoliths and to evaluate the groundwater storage in the overburden. The outstanding geohydrological features detected in the two study areas are: 1. (1) A widespread zone of saturation in the weathered mantle which implies a high success ratio for well-sinking programmes and which provides the evidence that baseflow from the regolith aquifers is a component of the main rivers' discharge. The basin-anddome weathering pattern, however, gives rise to locales of exceptionally thick ground-water zone. 2. (2) A direct relationship between saturated zone thickness and weathering depth which implies that water wells should penetrate the entire weathering profile to ensure maximum and perennial yields. 3. (3) Depth to water table significantly increases from the main river channels to the major water divides, a finding that conforms with an established geohydrological principle and which implies that the depths needed for wells at specific sites in the studied catchments can be reliably predicted in advance of the actual digging or drilling operations. 4. (4) A vast quantity of groundwater resources is stored in the regolith and as much as about 55% of the total storage is recoverable as well-water, baseflow in the main rivers, and as springwater.

Deep Weathering of Interfluves in the Basement Complex of South-Western Nigeria: Its Geomorphological and Geohydrological Implications

This paper derives from a quantitative study of deep interfluve weathering in three humid low-relief crystalline rock areas in south-western Nigeria. The irregular contour of the basal weathering surface is clearly evidenced in each study area. Weathering depth, depth to the water table and thickness of the saturated zone in the regolith increase generally with distance from the main river channels to the major watersheds. The spatial distribution patterns are optimally described by empirical equations computed by the least-squares method. The deep-weathering episode appears to predate the evolution of the existing drainage systems whose remarkably low densities, attributable to the high infiltration capacity of the regolith, are indicative of a low rate of denudation in the interfluves. Possible future emergence of ruwares or inselbergs is discernible at several sites but the rates of regolith stripping that would permit a reliable estimation of when the actual exhumation would occur at specific sites require further research. The widespread zone of saturation in the regolith is indicative of substantial groundwater recharge in the overburden and a high success ratio for wells. The basins of decomposition are locally important as sites with exceptionally thick groundwater zone. A strong direct relationship exists between weathering depth and thickness of the saturated zone. The general spatial trend of depth to water table implies that the approximate depths for wells at specific locations in the interfluves can be reliably predicted prior to the actual digging or drilling operations. Evidence of baseflow from the regolith aquifers is convincingly provided by the dry-season flows of the main rivers which have incised to the bedrock.

Short Exposure Times in Argon Laser Iridotomy

Currently employed techniques utilizing a continuous wave argon laser for the production of peripheral iridotomies in the treatment of angle-closure glaucoma are successful in producing patient iridotomies; however, complications such as corneal, lenticular, and retinal burns have been experienced. We found that a combination of low energy, much shorter exposures and an overlapping stretch pattern also gave a high success ratio in terms of formation of a patent iridotomy while reducing the number of complications for both black and white patients. Highly encouraging was the absence of corneal edema of a severity sufficient to cause an interruption in the treatment.

Design of Gravel Packs in Deviated Wellbores

This paper describes a new technique for improving the effectiveness of gravel placement between the screen and the wellbore in deviated wells. This technique can be used to predict whether a set of design conditions leads to a complete gravel pack that fills the entire annulus of a wellbore, or to an unstable, incomplete gravel pack that leaves voids in the annulus. The design procedure was used to gravel pack several high-angle wells successfully. Introduction Sand production from unconsolidated formations long has been a source of completion problems. Millions of dollars are spent throughout the world each year to achieve effective sand-control measures. Millions more axe spent each year to remedy many originally successful procedures that fail before the reservoir is depleted. procedures that fail before the reservoir is depleted. Maximum reliability of initial sand-control practices is essential, therefore, particularly offshore and in remote locations where operating costs are high. The most widely used sand-control technique involves placing a screen in the wellbore and packing gravel placing a screen in the wellbore and packing gravel around it. The screen is sized to retain the gravel and the gravel, in turn, is sized to retain the formation sand. This technique has proven effective, especially when formation properties allow open-hole completions. In spite of properties allow open-hole completions. In spite of this success, many gravel-packing procedures have less than desirable effectiveness because of unstable or incomplete placement of gravel around the screen. This is particularly true when the wellbores are deviated. As a particularly true when the wellbores are deviated. As a result, there is considerable incentive to develop gravel-packing techniques that have both high initial success ratio and the ability to provide sand-free production for sustained periods of time. Gravel packs in deviated wellbores need special design considerations. Recent gravel-packing studie's have shown that the wellbore angle has a dramatic effect on gravel placement - high angles can lead to unstable, incomplete gravel packs. In spite of the need to know the factors that control gravel placement in deviated wellbores, little has been published on the relationship between the fluid mechanics of gravel packing and the final distribution of gravel in deviated wellbores. This is a serious limitation because high-angle wells can be gravel packed effectively when the design conditions are packed effectively when the design conditions are selected correctly. Observations made while gravel packing a small-scale laboratory wellbore model are discussed in this paper. Then, the process by which gravel is transported in deviated wells is described. Finally, the development of a new design technique is reported that can be used to predict whether a set of design conditions can lead to a predict whether a set of design conditions can lead to a complete gravel pack that fills the entire wellbore-screen annulus, or to an unstable, incomplete gravel pack that leaves voids in the annulus. Gravel-Packing Apparatus The dynamics of gravel transport in deviated wellbores can be studied most effectively when the process can be visualized. The experiments described here were conducted in two transparent Lucite wellbore models: a small-scale, 3-in. (7.62-cm)-ID model that was 10 ft (3.05 m) long, and a full-scale, 5 1/2-in. (13.9-cm)-ID model that was 20 ft (6.09 m) long. Fig. 1 shows the details of the small-scale model. A 1.9-in. (4.83-cm)-OD wire-wrapped screen with 0.012-in. (0.305-mm) slots was centered inside the Lucite tube. A stainless-steel tube with 1/2-in. (1.27-cm) OD was placed inside the screen to simulate the tailpipe. JPT P. 109

Reduction Of Water-Oil Ratio Using Polyacrylamides In Vugular Carbonate Reservoirs

Abstract The use of partially hydroiyzed polyacrylamides to control water production in oil wells has been attempted in various areas of North America over the past ten years. This use has met with various amounts of success. It is felt that a careful evaluation of past treatment techniques and materials compared to well response can provide valuable data applicable to future treatment design. The purpose of this paper is to review and evaluate past treatments and show how the information developed has been used to design specific treatments. The results of these treatments, in turn, are evaluated in an attempt to establish guidelines for engineering future treatment designs to achieve a higher success ratio. Introduction Many oil wells produce throughout their lives without serious problems arising from undesirable fluid movement. The producing zones in these wells appear to have reasonably uniform permeability distribution, with a horizontal permeability much greater than the vertical permeability. Other formations have poor effective permeability, which can create problems during the producing life of a well. Fluid flow through 'such formations will occur in the zones of highest permeability. As the effective vertical permeability approaches the effective horizontal permeability, cross flow or vertical movement of water can cause coning. The petroleum industry has long recognized the need for a material to control the unwanted movement of water into producing wells. The task of providing such a material has been difficult due to wide variations in well and reservoir conditions. It has been further complicated by the very manner in which the permeability exists. The permeability of a rock formation may exist as matrix permeability, as hairline fracture permeability or as a result of connecting vugs or large pores in the rock. Artificial permeability, such as hydraulically induced fractures, can create unequal permeability distribution. Because of the wide variations in well and reservoir conditions, many materials and techniques have been used to reduce water production in oil wells. Because the problems of matrix sealing and fluid diversion within a formation are 50- complex, no single material can be expected to solve them all. Water Shut-Off Techniques Many materials and techniques have, been proposed to reduce water production in producing oil wells. Some of these are:Cement Plugs(1–5)Diesel Oil-Cement Squeezes(6–8)Emulsion Plugging(9)In-situ Polymerization AgentsPolymeric Water Gels(10–12)Polyisocyanurate Salts(13,14)Furfuryl Alcohol Resins(15)Lignosulphate Gels(16,17)Silica Gels(18,20)Polymers(20–28)Biopolymers(20–28)Polyelectrolytes(29)Polyacrylamides(30–58) Each of the above materials or techniques has shown some degree of promise. However, each 'has a limited application, because it is suitable only to a particular set of well or reservoir conditions. Of all these materials, the polyacrylamide polymers probably have the widest application for controlling water production from producing oil wells. Considerable controversy still exists as to the mechanisms by which these polymers -function to reduce water production

A method for the consistent production of high quality antisera to small peptide hormones

The high success ratio of this method for production of high quality antisera against several small peptides, suggests that this method may be useful for other small antigens. Successful preliminary results with prostaglandine E and thyroxine support this assumption.

Statistical Summary of Wells Drilled Below 18,000 Feet (5,500 Meters) in West Texas and Anadarko Basin: GEOLOGIC NOTES

Wells drilled to depths greater than 18,000 ft (5,500 m) in West Texas-New Mexico and Texas Panhandle-Oklahoma show encouraging results. In comparison to nationwide data, the ultradeep wells in these two regions show higher success ratios and lower increase, percentage-wise, in costs. Estimates of productive capacities from initial potentials of ultradeep producers apparently are not depth dependent.

Oil from beneath britain's seas

Abstract This short paper, presented to the British Association at Guildford in September 1975, summarizes the exploration, engineering and environmental problems involved in the discovery and development of North Sea oil. The discovery of the oil and gas fields, with a notably high success ratio, depended on the development of highly sophisticated methods of seismic survey and data analysis. The subsequent engineering operations have involved technology well beyond previous practice as regards the use of equipment, the water depth and a highly adverse environment.