Results 41 to 50 of about 1,206,493 (389)

A converse to the log-log law for Martingales [PDF]

Journal of the Australian Mathematical Society, 1974
For sums of independent and identically distributed random variables xn, the HartmanWintner law of the iterated logarithm is equivalent to xn ∈ L2. We show that this is also true when the xn, form a stationary, ergodic martingale difference sequence. This is accomplished by extending a theorem of Volker Strassen to the present context.
openaire   +2 more sources

A Method for Evaluating the Digital Precision of Induction Logging Tools

Cejing jishu
For an induction tool, its digital precision is critical for ultimate accuracy in actual measurements, and it actually determines the dynamic range of the resistivity, especially the high-resistivities.
ZHAO Yanwei, LIANG Xiaobing, SUN Xuekai, CHEN Wen, LIU Yue, JIANG Liming, ZHU Ruiming   +6 more
doaj   +1 more source

Bell Numbers, Log-Concavity, and Log-Convexity [PDF]

Acta Applicandae Mathematica, 2000
Let $\{b_{k}(n)\}_{n=0}^{\infty}$ be the Bell numbers of order $k$. It is proved that the sequence $\{b_{k}(n)/n!\}_{n=0}^{\infty}$ is log-concave and the sequence $\{b_{k}(n)\}_{n=0}^{\infty}$ is log-convex, or equivalently, the following inequalities hold for all $n\geq 0$, $$1\leq {b_{k}(n+2) b_{k}(n) \over b_{k}(n+1)^{2}} \leq {n+2 \over n+1 ...
Hui-Hsiung Kuo, Izumi Kubo, Nobuhiro Asai   +2 more
openaire   +2 more sources

Salvage logging effects on regulating and supporting ecosystem services — a systematic map

Canadian Journal of Forest Research, 2018
Wildfires, insect outbreaks, and windstorms are increasingly common forest disturbances. Post-disturbance management often involves salvage logging, i.e., the felling and removal of the affected trees; however, this practice may represent an additional ...
A. B. Leverkus, J. M. Rey Benayas, J. Castro, D. Boucher, Stephen Brewer, B. Collins, D. Donato, S. Fraver, B. Kishchuk, Eun-Jae Lee, D. Lindenmayer, E. Lingua, E. Macdonald, R. Marzano, C. Rhoades, A. Royo, S. Thorn, J. Wagenbrenner, Kaysandra Waldron, T. Wohlgemuth, L. Gustafsson   +20 more
semanticscholar   +1 more source

Research on Sensor Based on Optical Fiber Sensing for Acoustic Remote Detection

Cejing jishu
In view of the problems faced by traditional acoustic long-range detection tools in logging, such as “can not going down, uncertainty and data discontinuity”, the research on acoustic long-range detection technology based on optical fiber sensing is ...
HE Quanlong, CHEN Tao, SUN Shaowei, CHEN Wenhui, LIU Guoquan, WANG Shuihang, HAN Zhao, LU Wanting, CHEN Xiaoan   +8 more
doaj   +1 more source

Method for Evaluating Formation Fracturing Effect Utilizing Array Acoustic Logging

Cejing jishu
Fracturing of unconventional oil and gas reservoirs is an effective means to increase oil and gas recovery rate of tight reservoirs. It is also an important part of subsequent exploration and development of oil and gas fields.
LI Siyi, CHEN Wenhui, SUN Xuekai, JIANG Liming, GOU Yanhong, SUN Hao, SHI Peng, WEN Rou   +7 more
doaj   +1 more source

Single-Sand Configuration Technology of Horizontal Wells Based on Depositional Models Constraints

Cejing jishu, 2023
As one of the earliest development areas in Tarim oilfield, the TI oil group in L10 well area has entered the middle and high water cut stage. The sedimentary system is complex, and the reservoir sedimentary facies change quickly.
ZHOU Jingping, LI Ning, ZHENG Xiaomin, LI Jianjun, XU Ning, LI Zhihong   +5 more
doaj   +1 more source

The unpredictably eruptive dynamics of spruce budworm populations in eastern Canada

Population Ecology, EarlyView.
We examine historical population data for spruce budworm from several locations through the period 1930–1997, and use density‐dependent recruitment curves to test whether the pattern of population growth over time is more consistent with Royama's (1984; Ecological Monographs 54:429–462) linear R(t) model of harmonic oscillation at Green River New ...
Barry J. Cooke, Jacques Régnière
wiley   +1 more source

Theoretical Research and Simulation Experiment Analysis on Heat Transfer of Logging Tools

Cejing jishu
In order to ensure the deep development of oil exploration, improve the temperature and pressure resistance indicators of logging tools, and solve the problem of thermal failure of logging tools circuits, this article focuses on the theoretical research ...
WANG Dongyu, ZHANG Chongru, WANG Xiaodong, WANG Jun, ZHANG Dingjie, CHEN Wenhui   +5 more
doaj   +1 more source

A Method of Productivity Prediction for Multi-Fractured Horizontal Well

Cejing jishu, 2023
The reservoir of horizontal wells in a block of Junggar basin is tight and highly heterogeneous. After large-scale volume fracturing by classification and clustering, there is a large difference in production.
YANG Fan, GAO Yanwu, SHAO Guanghui, LIU Jieli, XU Rui, ZHOU Jufeng   +5 more
doaj   +1 more source