Flag System Research Articles

Flag systems and ordinary differential equations

We discuss the Monge problem in the theory of ordinary differential equations and prove the Cartan criterion for first order Monge systems with the added hypothesis of homogeneity. Next, we examine Hilbert's counter-example and finally give a brief account on the two special cases involving flag systems of length two and three.

Semimodular Lattices and Semibuildings

In a ranked lattice, we consider two maximal chains, or “flags” to be i-adjacent if they are equal except possibly on rank i. Thus, a finite rank lattice is a chamber system. If the lattice is semimodular, as noted in [9], there is a “Jordan-Holder permutation” between any two flags. This permutation has the properties of an S_n-distance function on the chamber system of flags. Using these notions, we define a W-semibuilding as a chamber system with certain additional properties similar to properties Tits used to characterize buildings. We show that finite rank semimodular lattices form an S_n-semibuilding, and develop a flag-based axiomatization of semimodular lattices. We refine these properties to axiomatize geometric, modular and distributive lattices as well, and to reprove Tits‘ result that S_n-buildings correspond to relatively complemented modular lattices (see [16], Section 6.1.5).

Assessment of three interface elements and modification of the interface element in CRISP90

Abstract To model the interaction between a buried pipeline and the surrounding soil either special interface elements or thin conventional elements may be used. In this study the CRISP90 interface element, the DRCRISP interface element and a conventional 8-noded quadrilateral element have been examined and their behaviour compared for a variety of loading conditions. Initial studies reveal that all these elements have limitations and are only suitable for monotonic loading and situations where tensile conditions do not occur across the interface. In the light of these findings the CRISP90 interface element has been modified by introducing a limiting adhesive strength in the normal direction; a flag system has also been introduced to track the various conditions of separation and closure for any gap that is formed. The results of single element and other benchmark tests show that the modified element can satisfactorily model the different modes of deformation relevant to soil–structure interface problems.

Evaluating the CELL-DYN 3500 haematology analyser in an acute general hospital.

The CELL-DYN 3500 (CD3500) (Abbott Diagnostics Division, Santa Clara, CA, USA) is a multiparameter, automated haematology analyser system capable of producing 22 haematological parameters including a screening five-part differential. The evaluation was performed in a recently expanded acute care general hospital. Studies of linearity, carryover and precision were acceptable and within manufacturer's stated limits. Correlation of CD3500 with manual differential counts were good except for the basophil count. The white cell flagging system had a sensitivity of 83.6% and specificity of 88.9% with 85.6% agreement. The platelet flagging system also had comparable sensitivity and specificity rate of 88.4% and 94.5% and agreement rate of 92.2%. The overall false positive rate and false negative rate for both the white cell and platelet flags combined were 8.6% and 10.3%. All samples provided a differential with no rejection experienced. The MAPSS technology, together with the extended lyse mode and the investigational nine-part differential provides potential for future development in WBC differential.

Truth in SPEC benchmarks

The System Performance Evaluation Cooperative (SPEC) benchmarks are a set of integer and floating-point programs that are intended to be “effective and fair in comparing the performance of high performance computing systems”. SPEC ratings are often quoted in company advertising and have been trusted as the de facto measure of comparison for computer systems. Recently, there has been some concern regarding the fairness and the value of these benchmarks for comparing computer systems. In this paper we investigate the following two questions regarding the SPEC92 benchmark suite: 1) How sensitive are the SPEC ratings to various tunings? 2) How reproducible are the published results? For six vendors, we compare the published SPECpeak and SPECbase ratings, and observe an 11% average improvement in the SPECpeak ratings due to changes in the compiler flags alone. In our own attempt to reproduce the published SPEC ratings, we came across various “explicit” and “hidden” tuning parameters that we consider unrealistic. We suggest a new unit called SPECsimple that requires using only the -O compiler optimization flag, shared libraries, and standard system configuration. SPECsimple is designed to better match the performance experienced by a typical user. Our measured SPECsimples are 65-86% of the advertised SPECpeak performance. We conclude this paper by citing cases compiler optimizations specifically designed for SPEC programs, in which performance decreases drastically or the computed results are incorrect if the compiled program does not exactly match the SPEC benchmark program. These findings show that the fairness and value of the popular SPEC benchmarks are questionable.

A Field Evaluation of the Coulter STKS®

The performance of the Coulter STKS (Coulter, Hialeah, FL) was evaluated in a busy computerized teaching hospital laboratory. The STKS was compared with a Coulter S Plus IV and manually performed 400 white blood-cell differentials. The measured blood-count parameters (i.e., white blood cells [WBCs], red blood cells [RBCs], hemoglobulin [Hb], mean corpuscular volume [MCV], and platelets [PLTs]), compared very well between the two aperture impedance-based systems; precision, linearity, and lack of carryover were excellent. The STKS WBC differential (DIFF), derived from a combination of aperture impedance, aperture conductance, and laser light scatter, also was precise; linear and carryover were insignificant. The DIFFs (n = 424) compared well to the manual WBC differentials, with r values of 0.97, 0.97, 0.73, and 0.86 for neutrophils, lymphocytes, monocytes, and eosinophils, respectively. The DIFF and Suspect Flagging system produced 6.2% false negatives and 2.6% false positives when compared with the manual technique. These were further investigated and discussed. STKS DIFFs were stable for 18 to 24 hours in normal samples anticoagulated with K2EDTA and stored at 20 degrees C prior to analysis. Storage in the same anticoagulant at 4 degrees C and immediate aspiration preserved the DIFF analysis for considerably longer than 24 hours. These performance characteristics make the STKS a significant advancement in automated hematology.

Managing Violent Patient Incidents: The Role of a Behavioral Emergency Committee

The Portland (Oregon) Veterans Administration Medical Center acknowledged the problem of dealing with aggressive and disruptive patients by establishing a behavioral emergency committee (BEC). The BEC first introduced a system for tracking disruptive patient incidents and then initiated an electronic flagging system for violence-prone patients that alerts medical center clinical and security personnel when a potentially dangerous patient is present. The committee also coordinates violence control training for medical center personnel. Since the BEC was formed, disruptive behavior among this high-risk patient group has been significantly reduced.

Enumerating maximal-order abelian groups within a set of eligible elements

An implicit enumeration algorithm for finding maximal-order abelian groups contained within a set of potential group elements is described. The problem of finding such groups arises in the area of experimental design when certain symmetrical fractional factorials are desired. Simple complete enumeration algorithms are inefficient in the sense that each distinct group is generated more than once. The proposed algorithm utilizes a system of flags in conjunction with a subset selection procedure such that each distinct group is generated exactly once. The algorithm is applied to problems in the design of experiments, and solutions are presented.

Behavior of Jointed Ductile Iron Pipelines

Experimental data on the axial, bending and torsional behavior of ductile cast iron pipes with rubber gasket joints is presented. Analytical expressions are provided which predict the resistance mechanisms and behavior of the joints. The bending mechanism is found to be quite different from the axial and torsional mechanism. By repeating the tests in a specially designed soil box, the effects of burial depths are determined. A joint stiffness matrix including axial, bending and torsional effects is provided. The slip behavior of the joint changes the stiffness values, however this occurence may be dealt with by using an appropriate flag system. To minimize axial compressional stresses and interlocking bending stresses at the joint, a minor geometrical change in the joint needs to be made. Joints with larger lip lengths provide more flexibility when subjected to axial compression or joint bending rotations.

Response of Microtus pennsylvanicus to multiple-capture traps

Microtus pennsylvanicus was livetrapped on demographic grids in Ontario and Manitoba to determine the efficiency of Longworth and one-way door multiple-capture traps. In paired-choice field trials, multiple-capture traps caught far fewer voles than did Longworth traps. Sand-tracking and a flagging system indicated that voles rarely lifted the one-way door of the multiple-capture trap, although they often approached the traps and began to enter the one-way door.

Colonial Military Flags

E I TTLE is known about the flags carried by the military companies in the time of Charles I, but from the fact that in ....m~-~:! 1643, at the outbreak ~~ ' _ of the Civil War in Detail from the portrait of England, the same Captain Thomas Savage, I679 system of divisional flags was in use in both armies (the King's and Parliament's), it seems safe to assume that this indicates that both armies followed the usage, previously current, in the reign of Charles I. Samuel Milne Milne, the leading authority on British military flags, in his exhaustive volume The Standards and Colours of the Army, i66I-i88r, referring to this period, writes: