The emerging interventionists of the GCC

There is a shift occurring within the Gulf Cooperation Council (GCC) in which new regional leaders are emerging, buoyed by a decade of unprecedented wealth generation from the 2000s commodities boom and increased foreign investment. Specifically, Qatar and the United Arab Emirates (UAE) have emerged as activist states in their interest and willingness to intervene both militarily and financially in the politics of neighbouring Arab states. Contrary to their collective and individual foreign policies of the last 40 years, the GCC states have intervened in each other’s domestic politics and in the domestic politics and revolutions of the wider Middle East and North Africa region. While Saudi Arabia enjoyed a period of dominance among its Gulf Arab neighbours for many years, even occasionally threatening the borders of Qatar and the UAE, the prevailing policy of Gulf states has been non-interference and support for Arab leaders, as a principle of religion and politics. In essence, the evolving nature of interventionism in the GCC is moving away from Saudi dominance towards the emergence of new actors willing to engage in the region and on the international stage. We can trace this policy shift through the simultaneous yet separate evolution of domestic, regional and international political economy. This paper argues that shifts in leadership at the national levels have coincided with larger trends in the regional and international economy which have enabled different, yet both assertive, interventionist foreign policies to emerge from Qatar and the UAE. The result is a moment of financial and military interventionism unprecedented in Arab Gulf politics

Approximating 1-dimensional TSP Requires Omega(n log n) Comparisons

We give a short proof that any comparison-based n^(1-epsilon)-approximation algorithm for the 1-dimensional Traveling Salesman Problem (TSP) requires Omega(n log n) comparisons.Comment: Superseded by "On the complexity of approximating Euclidean traveling salesman tours and minimum spanning trees", by Das et al; Algorithmica 19:447-460 (1997

A Bound on the Sum of Weighted Pairwise Distances of Points Constrained to Balls

We consider the problem of choosing Euclidean points to maximize the sum of their weighted pairwise distances, when each point is constrained to a ball centered at the origin. We derive a dual minimization problem and show strong duality holds (i.e., the resulting upper bound is tight) when some locally optimal configuration of points is affinely independent. We sketch a polynomial time algorithm for finding a near-optimal set of points.Comment: Cornell ORIE Tech Repor

On-Line File Caching

In the on-line file-caching problem problem, the input is a sequence of requests for files, given on-line (one at a time). Each file has a non-negative size and a non-negative retrieval cost. The problem is to decide which files to keep in a fixed-size cache so as to minimize the sum of the retrieval costs for files that are not in the cache when requested. The problem arises in web caching by browsers and by proxies. This paper describes a natural generalization of LRU called Landlord and gives an analysis showing that it has an optimal performance guarantee (among deterministic on-line algorithms). The paper also gives an analysis of the algorithm in a so-called ``loosely'' competitive model, showing that on a ``typical'' cache size, either the performance guarantee is O(1) or the total retrieval cost is insignificant.Comment: ACM-SIAM Symposium on Discrete Algorithms (1998

Nearly Linear-Work Algorithms for Mixed Packing/Covering and Facility-Location Linear Programs

We describe the first nearly linear-time approximation algorithms for explicitly given mixed packing/covering linear programs, and for (non-metric) fractional facility location. We also describe the first parallel algorithms requiring only near-linear total work and finishing in polylog time. The algorithms compute $(1+\epsilon)$-approximate solutions in time (and work) $O^*(N/\epsilon^2)$, where $N$ is the number of non-zeros in the constraint matrix. For facility location, $N$ is the number of eligible client/facility pairs

Sequential and Parallel Algorithms for Mixed Packing and Covering

Mixed packing and covering problems are problems that can be formulated as linear programs using only non-negative coefficients. Examples include multicommodity network flow, the Held-Karp lower bound on TSP, fractional relaxations of set cover, bin-packing, knapsack, scheduling problems, minimum-weight triangulation, etc. This paper gives approximation algorithms for the general class of problems. The sequential algorithm is a simple greedy algorithm that can be implemented to find an epsilon-approximate solution in O(epsilon^-2 log m) linear-time iterations. The parallel algorithm does comparable work but finishes in polylogarithmic time. The results generalize previous work on pure packing and covering (the special case when the constraints are all "less-than" or all "greater-than") by Michael Luby and Noam Nisan (1993) and Naveen Garg and Jochen Konemann (1998)

Considerations in the placement of phase calibration tones

In the use of tones to calibrate unwanted instrumental phases for very long baseline interferometry experiments, certain problems exist which are related to the placement of these phase calibrator tones. (1) A bias exists in an analytically generated stopping function used during correlation if its frequency satisfies the following condition; f = (f sub s)x(m)/n, where f sub s = sampling frequency, m = any integer, and n = any odd integer. (2) Due to the quantized representation of sine waves in the stopping function, odd harmonics of the fundamental frequencies are generated. Several mechanisms are available through which these harmonics can cause errors in the residual phase extracted from the recorded tones. (3) When multiple tones are injected into a pass band, intermodulation products can occur. The magnitude of these effects is discussed along with strategies designed to avoid them

Transient behavior of arterial systems in response to flow pulses

Transient analysis of arterial fluid lines with respect to time domains and pulse widt