485 research outputs found
中日民間説話における異類婚姻譚の比較研究 : 20世紀以降のタイプとモチーフを中心に
内容の要約広島大学(Hiroshima University)博士(文学)Doctor of Philosophydoctora
An Analysis of a New P2P Trust Control Model
In order to monitor efficiently the selfish behavior on networks, form reliable relations and prevent problems such as the single point of failure or bottleneck effect in traditional client-server environments, we adopt a novel P2P trust arithmetic-P-Trust referring to the social people trust relation mechanism. The direct trust arithmetic and the recommend trust arithmetic are particularly described. The P-Trust integrates the direct trust value and recommend trust value to create the final trust value. Simulations prove the P-Trust arithmetic can tackle the P2P trust problem in a simple and efficient way
Technology for Improving Life of Thermal Recovery Well Casing
In steam injection process, casing is heated by steam, the change of casing temperature produces thermal stresses in the casing, the casing deforms when stresses exceed the yield point of its material. Casing failure is becoming increasingly prominent in thermal recovery wells, which severely restricts the development effect of such reservoirs, improving casing life of thermal recovery well has become a urgent problem to be solved. Through on-site survey and analysis, reasons for casing damage were determined as follows: strength change by high temperature, sand flow over of oil formation, poor cementing, unfavorable heat insulation and bad material for casing. In order to improve casing life, the supporting measures are introduced, the measures include pre-stress cementing technology, using casing head, thermal stress compensator, high-performance insulation tubing, high temperature cement slurry system, FRT110H special casing, and early sand control completion technology. Field application of these measures has gotten better effect in Shengli oilfield in recent years, the damage rate of thermal recovery well has decreased obviously, and this can provide reference for the efficient development of similar reservoirs at home and abroad.Key words: Casing failure; Thermal recovery wells; Special casing; Cementing; Sand control completio
Investigations of similar folk stories between China and Japan: Focus on The Tale of the Bamboo Cutter and The Girl from Mottled Bamboo
The Tale of the Bamboo Cutter (Taketori Monogatari) is called "The ancestor of tales", as it is the oldest one in Japan. The author and the year it was created are unknown, but it has a high status in the history of Japanese literature. The Girl from Mottled Bamboo (Banzhu Guniang) is an old story that spread in Sichuan Tibetan areas of China, and is extremely similar to The Tale of the Bamboo-Cutter in many respects: the birth from bamboo, the problem of the proposed topic, the figures and story line. Therefore, it has drawn the attention of Chinese and Japanese scholars and has created controversy. This article focus on research activities and results regarding these two stories, pays important attention to the representative results of the comparative study dating back to the 1970s, and investigates the problems and deficiencies in previous research
Investigation of folktale compilation and type classification research between China and Japan
This study focuses on the definition and understanding of Chinese and Japanese folktales, paying careful attention to folktales that Chinese and Japanese scholars have collated, integrated, and published since the 19th century. Thus, by introducing the scholars' research achievements in the classification of folktale types in China and Japan, this study investigates the problems and deficiencies of previous research
Detection of arbitrarily-shaped clusters using a neighbor-expanding approach: A case study on murine typhus in South Texas
<p>Abstract</p> <p>Background</p> <p>Kulldorff's spatial scan statistic has been one of the most widely used statistical methods for automatic detection of clusters in spatial data. One limitation of this method lies in the fact that it has to rely on scan windows with predefined shapes in the search process, and therefore it cannot detect cluster with arbitrary shapes. We employ a new neighbor-expanding approach and introduce two new algorithms to detect cluster with arbitrary shapes in spatial data. These two algorithms are called the maximum-likelihood-first (MLF) algorithm and non-greedy growth (NGG) algorithm. We then compare the performance of these two new algorithms with the spatial scan statistic (SaTScan), Tango's flexibly shaped spatial scan statistic (FlexScan), and Duczmal's simulated annealing (SA) method using two datasets. Furthermore, we utilize the methods to examine clusters of murine typhus cases in South Texas from 1996 to 2006.</p> <p>Result</p> <p>When compared with the SaTScan and FlexScan method, the two new algorithms were more flexible and sensitive in detecting the clusters with arbitrary shapes in the test datasets. Clusters detected by the MLF algorithm are statistically more significant than those detected by the NGG algorithm. However, the NGG algorithm appears to be more stable when there are no extreme cluster patterns in the data. For the murine typhus data in South Texas, a large portion of the detected clusters were located in coastal counties where environmental conditions and socioeconomic status of some population groups were at a disadvantage when compared with those in other counties with no clusters of murine typhus cases.</p> <p>Conclusion</p> <p>The two new algorithms are effective in detecting the location and boundary of spatial clusters with arbitrary shapes. Additional research is needed to better understand the etiology of the concentration of murine typhus cases in some counties in south Texas.</p
Five-Section Trajectory Design of Thick Glutenite Reservoir in Shengli Oilfield
Many blocks of Shengli Oilfield are located in urban areas, and the site selection of well sites is limited. In order to meet the needs of reservoir development and deployment, five-section trajectory is increasingly used. Difficulty in site selection results in directional well development, and reservoir deployment requires vertical well development. In order to resolve the two contradictions, five-section trajectory is used in the well design, and vertical drilling after hitting the target. The problems with this type of trajectory are high torque drag and easier fatigue of the drilling pipe. When the displacement is small, the effect is small. When the displacement is large, it will cause engineering complexity such as difficulty drilling weight transfer and fatigue of drilling pipe. Aiming at the shortcomings of the five-section trajectory, with the help of existing drill string force analysis software, the parameters of the five-section trajectory were analyzed, and reasonable values were recommended to provide an optimization idea for the five-section trajectory
Finite-dimensionality of attractors for wave equations with degenerate nonlocal damping
In this paper we study the fractal dimension of global attractors for a class
of wave equations with (single-point) degenerate nonlocal damping. Both the
equation and its linearization degenerate into linear wave equations at the
degenerate point and the usual approaches to bound the dimension of the
entirety of attractors do not work directly. Instead, we develop a new process
concerning the dimension near the degenerate point individually and show the
finite dimensionality of the attractor.Comment: 33 page
Recent morphodynamic evolution of the largest uninhibited island in the Yangtze (Changjiang) estuary during 1998-2014: Influence of the anthropogenic interference
Estuarine geomorphology worldwide has greatly changed in the Anthropocene due to intensive human inferences in river basin and within estuary, which has received increasing global concerns. Here, recent morphodynamic evolution of Jiuduan Shoal (JDS), the largest uninhabited island in the Yangtze (Changjiang) Estuary, and associated controlling factors were analyzed based on unique high-resolution seasonal-surveyed bathymetric data during 1998–2014. It can be indicated that JDS presents novel 12 and 48 months fluctuations though significant accretion was detected on high flats above −2 m. Meanwhile, morphodynamic evolution of JDS during 1998–2014 was divided into three stages: significant siltation on land-ward half of north JDS and expanding of Jiangya Shoal (JYS, part of JDS) tail, but less accretion at high flats from 1998 to 2002; continuous variations of JYS and reshape of seaward JDS with erosion band and heave appearance from 2002 to 2006; retentive alteration of JYS but recovery of erosion band and heave, together with redistribution of sand between high and low flats on seaward JDS after 2007. Moreover, river discharge could be likely the key factor controlling periodic characteristics of recent JDS evolution. Deep waterway project (DWP) dominates area increase of JDS by inducing accretion in north edge and south edge of Lower Shoal between 1998 and 2014
- …