Algorithms for Generating Minimal Cutsets by Inversion

This paper studies the problem of inverting minimal paths to obtain minimal cutsets (or vice versa) for s-coherent systems. The theoretical results lead to simplified inversion by a sequential method. Strategies are discussed for implementing these simplifications efficiently. Computational results, obtained by applying the algorithms to standard problems drawn from the literature, indicate that a substantial reduction in computational effort can be achieved by such simplifications.     

What footdrumming signals in kangaroo rats (Dipodomys heermanni).

Footdrumming during social interaction was studied in kangaroo rats (Dipodomys heermanni). Behaviors that elicited and followed footdrumming during mixed-sex encounters between adults were examined. Females spent more time in the burrow and footdrummed. Males showed higher rates of digging and approaching the females' burrow: these acts were reliably followed by female footdrumming. Footdrumming was associated with male retreat. The authors then tested whether this effect reflected a difference in sex or in social status, using each possible dyad in triads (adult male, adult female, juvenile male). Juvenile males drummed to all adults, but females only drummed to adult males; relationships were transitive. Social context and initial approach tendencies account for the occurrence of footdrumming, which communicates unwillingness to interact, particularly from within the burrow. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A computational study of Floyd's algorithm

This paper studies the empirical computational complexity of five different computer codes for realizing Floyd's shortest path algorithm, using classes of randomly generated test problems. The present work investigates objective and reproducible measures of computational effort, and indicates how rather substantial reductions in this computational effort (as much as 30%, asymptotically) can be achieved. Both actual CPU time and predicted computation time are discussed and compared. Results indicate a strong interaction between code, computer, compiler, and several empirical measures of computational effort.     

可变径稳定器的强度设计与刚度设计

可变径稳定器与整体式稳定器（固定烃）相比，它更能有地保证井身质量，是目前较先进的钻井工具之一，目前我国还没有同类产品生产，本文所分析的可变径稳定器，是我院与四川石油管理局某机械厂联合研制的深井可变径稳定器，目前正在试制之中。本文利用有限元法，详细分析了该型号稳定器的强度和刚度，为设计提供了可靠的理论依据。     

Comparison of mathematical programming software: A case study using discrete L1 approximation codes

This paper presents the methodology and results of a computational experiment which compares the performance of four computer codes which determine the best discrete L₁ approximation to a continuous nonlinear function. The experiment utilizes 320 test problems created by a test problem generator. Several performance measures describe solution quality as well as computational effort.     

Maternal presence and rearing condition affect responses to live predator in kangaroo rats (Dipodomys heermanni arenae).

Experiment 1 compared the responses of wild-caught adult and captive-born adult and juvenile kangaroo rats (Dipodomys heermanni arenae) to a live snake. Wild-caught adult rats were less active and monitored the snake more than during a control condition; captive-born juvenile rats did not behave differently during snake and control tests. Snake-naive adult rats behaved more like the wild-caught adult rats, but not on all measures. In Experiment 2, pups were tested at 25 and 50 days of age in 4 conditions: no-snake control, alone with the snake, with a sibling and the snake, and with the mother and the snake. Pups did not behave differently during control and snake tests, but during tests with the mother, pups faced the snake less and followed the mother. Younger pups were more often near the mother than a sibling and followed the mother more when the snake was present. Development of defensive behavior may depend on both predator experience and maternal influence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The renal factor in the post-traumatic "fluid overload" syndrome

Hypervolemia with hypertension often occurs 36-72 hours following massive blood and fluid replacement for hypovolemic shock. This syndrome of "fluid overload" has been attributed to the rapid intravascular flux of previously sequestered fluid in patients with impaired diuresis. This hypothesis was tested in 35 injured patients who received a mean of 9.3 L of blood and 17.4 L of salt during resucitation. The renal parameters measured soon after resuscitation included: 1) renal clearance of inulin (GFR), para-amino hippurate (ERPF), milliosmoles, sodium, and free water; 2) inulin space, renal vascular resistance (RVR), O2 consumption, renin, renal blood flow (RBF), and response to furosemide. Eighteen patients developed hypertension, hypervolemia, and respiratory insufficiency. When compared to the 17 normovolemic, non-hypertensive patients, the 18 hypervolemic patients had significantly increased RVR, with a significant decrease in RBF despite an increase in plasma volume and cardiac output. Furosemide produced less diuresis and natriuresis in the hypertensive patients. The balance between hypovolemia and "fluid overload" seemed percarious in the hypertensive patients. Peripheral renin and catecholamine levels were normal in both groups. Patients with post-traumatic "fluid overload" appear to have a combination of hypervolemia, respiratory insufficiency, hypertension, increased cardiac output, decreased extracellular fluid space, and decreased renal perfusion. These findings suggest that decreased interstitial fluid space compliance rather than "fluid overload" is the underlying factor leading to respiratory insufficiency. The therapeutic aspects of these findings are discussed.     

我国现代节能墙体材料的革新与发展趋势

我国墙体材料的改革与发展,重点将在生产工艺创新和结构形式创新两方面:生产工艺创新体现在对工业废料、城市污泥、建筑废料的综合利用以及免烧工艺的发展;结构形式创新是将单一化的传统墙体结构形式转变成砖、砌块和板材等多种形式并存的局面。在此基础上,墙体材料将进一步向空心化和更加注重保温隔热性能的方向发展。     

从汶川大地震看钢结构的发展

"5.12"汶川大地震造成了巨大的人员伤亡和经济损失,许多公共建筑的倒塌更是引起了相关人员的广泛关注,与此同时土木工程师也在致力于寻求一种能达到防震减灾目的的建筑结构。由于钢结构具有重量轻,抗震性能好等优点将会在建筑住宅中也得到了越来越多的应用。在21世纪,钢结构住宅将拥有更为广阔的发展前景。通过对我国常用建筑结构的抗震性能分析比较,阐述钢结构的防灾抗震特点,以此说明发展钢结构住宅的意义。