MODELING THE MOVEMENTS OF COWBIRDS: APPLICATION TOWARDS MANAGEMENT AT THE LANDSCAPE SCALE

ABSTRACT. Brood parasitism by brown‐headed cowbirds (Molothrus ater) reduces the reproductive success of two endangered bird species at Fort Hood, Texas. A successful management program has focused on trapping cowbirds at feeding locations, grassland areas almost always associated with the presence of cattle. To enhance the efficacy of this effort, we developed an individual‐based model that predicted visitation rates by cowbirds to all potential feeding locations at Fort Hood and the surrounding landscape. Utilizing GRASS‐GIS and SWARM, the model incorporated the spatial arrangement of habitats, daily movements of cattle, and daily movements of cowbirds from their breeding sites to feeding locations. We simulated four types of movements by cow‐birds as they searched for cattle: 1) random walk, 2) direct return to previous locations (i.e., memory), 3) return to previous locations with en route assessment (i.e., memory with limited perception of the current state of the system), and 4) omniscience. Straight‐line distances between breeding and feeding locations for cowbirds that used the memory‐with‐perception rule were similar to independent telemetry results, and total search distances for this movement type approached those of omniscience. Both movement distance measures were inversely related to perception distance. Maps of cowbird visits to feeding areas differed among movement rules but were not strongly affected by the density of breeding cow‐birds. Maps also identified locations where trapping efforts could reduce parasitism within specific areas known to support endangered species. While it seems plausible that cowbirds are able to remember foraging locations and to perceive their surroundings as they travel, additional studies are needed to document their cognitive abilities. By simulating movements of individual cowbirds across a dynamic landscape, model results may help to strengthen ongoing cowbird control efforts.     

在NEAX61E交换机的MAT上创建新的人机界面

本文介绍了在ＮＥＡＸ６１Ｅ交换机的ＭＡＴ上访问交换机接口的方法，这个方法可以用来创建更友好的人机界面。     

I DDQ testing in CMOS digital ASICs

I _DDQ testing with precision measurement unit (PMU) was used to eliminate early life failures caused by CMOS digital ASICs in our products. Failure analysis of the rejected parts found that bridging faults caused by particles were not detected in incoming tests created by automatic test generation (ATG) for stuck-at-faults (SAF). The nominal 99.6% SAF test coverage required to release a design for production was not enough! This article shows how I _DDQ testing and supplier process improvements affected our early life failure rates over a three year period. A typical I _DDQ measurement distribution, effects of multiple I _DDQ testing, and examples of the defects found are presented. The effects of less than 99.6% fault coverage after the I _DDQ testing was implemented are reviewed. The methods used to establish I _DDQ test limits and implement the I _DDQ test with existing ATG testing are included. This article is a revision of one given at International Test Conference [1].     

光学设计的发展

本文概述了光学设计所处的历史发展阶段,对智能化光学设计给出了定性的描述,指出了目前光学设计要解决的问题以及发展方向。     

程控调度机软硬件的研制

程控调度机是一种用于大中型企业或部门的电话调度及管理的大型通信设备，近两年来，我国程控调度机的研制及生产已取得很大进展，本文结合作者的开发经验、谈谈程控调度机的功能、结构及软硬件研制问题。     

Temperature program optimization by computer simulation for the capillary GC analysis of fatty acid methyl esters on biscyanopropyl siloxane phases

The selectivity of capillary columns coated with biscyanopropyl siloxane stationary phases for the separation of fatty acid methyl esters has been optimized by means of computer-assisted column temperature optimization software. Temperature programming rates yielding the highest resolution in the shortest analysis time were selected for split, splitless, and on-column injection operated in the constant pressure and pressure programmed modes.     

A FORTRAN program for cluster enumeration

A simple FORTRAN program based primarily on the algorithm of Martin is presented for enumerating isolated connected clusters of up to a given specified number of particles on the square lattice. A brief explanation of the workings of the program is also provided to facilitate its use by those interested in this problem. To order 15, the program enumerates clusters at an average rate of approximately 63,000/sec when implemented on an IBM 370/168 with the extended optimizing compiler.Supported in part by grants from the ARO, NSF, and ONR.     

An interactive computer program for elliptical beam optimization

Elliptical antenna beams are used for planning of direct broadcast satellite systems. In this paper concepts of the beam optimization process are described briefly. A method of plotting the optimized beam on a suitable map projection is discussed. An interactive computer program, which can be used for the optimization and plotting of beams on a given territory, is described with the help of examples.     

Mixed-integer bilinear programming problems

This paper addresses a class of problems called mixed-integer bilinear programming problems. These problems are identical to the well known bilinear programming problems with the exception that one set of variables is restricted to be binary valued, and they arise in various production, location—allocation, and distribution application contexts. We first identify some special cases of this problem which are relatively more readily solvable, even though their continuous relaxations are still nonconvex. For the more general case, we employ a linearization technique and design a composite Lagrangian relaxation-implicit enumeration-cutting plane algorithm. Extensive computational experience is provided to test the efficacy of various algorithmic strategies and the effects of problem data on the computational effort of the proposed algorithm.