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Experiments with both four-level and two-level factors have been conducted in many different domains, ranging from engineering to ergonomics. In such experiments, the four-level factors are used in three different ways: as blocking factors, as qualitative factors, or as quantitative factors. However, it was generally not easy for the authors to find an appropriate design for their experiment. A solution to this problem is to use a catalog of designs with a wide range of options. To efficiently use such a catalog, one needs criteria to identify the best designs. We present good criteria for the three different usages of four-level factors, and we apply these criteria to the catalog of Bohyn et al. (J R Stat Soc Ser C: Appl Stat 72:750–769, 2023). Finally, we present tables of four-and-two-level designs that are optimal with respect to the different criteria, for run sizes 16, 32, 64 and 128, with 1, 2, or 3 four-level factors, and up to 20 two-level factors. [ABSTRACT FROM AUTHOR]

An m×nrow‐column factorial design is an arrangement of the elements of a factorial design into a rectangular array. Such an array is used in experimental design, where the rows and columns can act as blocking factors. Formally, for any integer q, let [q]={0,1,...,q−1}. The qk (full) factorial design with replication α is the multiset consisting of α occurrences of each element of [q]k; we denote this by α×[q]k. A regularm×nrow‐column factorial design is an arrangement of the elements of α×[q]k into an m×n array (which we say is of typeIk(m,n;q)) such that for each row (column) and fixed vector position i∈[k], each element of [q] occurs n∕q times (respectively, m∕q times). Let m≤n. We show that an array of type Ik(m,n;q) exists if and only if (a) q∣m and q∣n; (b) qk∣mn; (c) (k,q,m,n)≠(2,6,6,6), and (d) if (k,q,m)=(2,2,2) then 4 divides n. Godolphin showed the above is true for the case q=2 when m and n are powers of 2. In the case k=2, the above implies necessary and sufficient conditions for the existence of a pair of mutually orthogonal frequency rectangles (or F‐rectangles) whenever each symbol occurs the same number of times in a given row or column. [ABSTRACT FROM AUTHOR]

Summary: Experimental design and analysis has evolved substantially over the last 100 years, driven to a large extent by the power and availability of the computer. To demonstrate this development and encourage the use of experimental design in practice, three experiments from different research areas are presented. In these examples multiple blocking factors have been employed and they show how extraneous variation can be accommodated and interpreted. The examples are used to discuss the importance of blocking and treatment structures in the conduct of designed experiments. [ABSTRACT FROM AUTHOR]

Manganese ferrite (MnFe2O4) nanoparticles and Cu0.5Tl0.5Ba2Ca2Cu3O10−δ(CuTl-1223) superconducting phase were synthesized by sol-gel and solid-state reaction methods, respectively. Different contents of MnFe2O4 nanoparticles were added in CuTl-1223 superconducting matrix to get (MnFe2O4)x/CuTl-1223; x =  0∼2.0 wt% nanoparticles-superconductor composites. Complex electric modulus spectroscopy measurements of (MnFe2O4)x/CuTl-1223 composites were carried out at different test frequencies from 20 Hz to 10 MHz and at different operating temperatures from 78 to 253 K to analyze and interpret the dynamical aspects of electrical transport phenomena (i.e., such as carrier hopping rate, conductivity, and blocking factor). The complex electric modulus spectra showed the effects of both grains and grain-boundaries on electrical properties. The capacitance of grain-boundaries was found higher than that of grains. The capacitive behavior of grains was increased and that of grain-boundaries was decreased with increasing operating temperature for all these samples. Blocking factor of these composites was increased with increasing contents of MnFe2O4 nanoparticles. Shifting of peaks in imaginary part of modulus spectra towards lower frequency with increasing contents of these nanoparticles showed non-Debye type relaxation phenomenon in the material. [ABSTRACT FROM AUTHOR]

Aspects of static verification of software applications for real-time systems are considered. A verification method based on oriented multipartite graphs is suggested for checking whether mutual blockings (deadlocks or clinches) could occur in a real-time multitask application and estimate the duration of highpriority task blocking by lower-priority tasks due to the application structure. [ABSTRACT FROM AUTHOR]

Background IgE-mediated allergic rhinitis to grass pollen can successfully be treated with either allergen immunotherapy tablets ( SLIT tablet) or SQ-standardized subcutaneous immunotherapy ( SCIT). The efficacy of these two treatment modalities for grass allergy is comparable, but the immunological mechanisms may differ. ClinicalTrials.gov ID: NCT01889875. Objectives To compare the immunological changes induced by SQ-standardized SCIT and SLIT tablet. Methods We randomized 40 individuals with grass pollen rhinitis into groups receiving SCIT, SLIT tablet, or neither and followed them for 15 months with regular serum measurements of specific Ig E, Ig G4, Ig E-blocking factor, facilitated antigen presentation ( FAP), and basophil activation test ( BAT). Nasal challenges were used to assess changes in nasal sensitivity. Results After 15 months of treatment Ig G4, Ig E-blocking factor, FAP, and BAT values differed significantly in both SCIT and SLIT-tablet treatment groups when compared to the control group. Both SCIT and SLIT-tablet groups were significantly different from the control group after 1-3 months of treatment. In general, the changes induced by SCIT reached twice that of SLIT tablet, with the exception of specific Ig E where SLIT tablet induced initial threefold increase compared with SCIT. A slight but significant increase in Ig E and BAT after season was seen only in the control group. Significant differences between SCIT and SLIT tablet were observed early, but the differences diminished with the length of treatment, especially for FAP inhibition. Conclusions Both SCIT and SLIT tablet induce significant changes in specific antibodies ( Ig E and Ig G4) and competition assays ( Ig E-blocking factor, FAP, and BAT). Overall, SCIT induced larger (two- to threefold) changes than SLIT tablet, with the exception of FAP, where SLIT tablet showed a gradual increase ending at the same level as SCIT. Maximal change was generally reached after 3 months' treatment. [ABSTRACT FROM AUTHOR]

When studying scalability in ad-hoc networks, most works present experimental results for a limited number of nodes (100–200). Various “explicit” clustering techniques have been proposed to improve scalability, obtaining successful sessions for 400–800 nodes. However, explicit clustering may damage the performance, e.g., cause session breaks due to fast movements of cluster heads. An alternative to explicit clustering is the use of algorithms that are “naturally clustered”, i.e., arrange the nodes in dynamic hierarchical structures. In this work, we study the effect of explicit clustering by comparing an advanced version of the Ad Hoc Distance Vector Algorithm (AODV) with the Metrical Routing Algorithm (MRA) that possesses the natural clustering property. We cover fundamental aspects of scalability and experimentally prove the superiority of implicit clustering over explicit clustering. In particular, we consider heterogeneous theaters with several types of transmitters including personal, car-mounted, helicopters and a Geostationary (GEO) satellite. Natural clustering is more effective in heterogeneous theaters as the more powerful transmitters can serve as cluster heads. A formal bound based on general probabilistic assumptions shows that all existing ad-hoc algorithms cannot scale infinitely, thus rendering scalability as an experimental issue. [ABSTRACT FROM AUTHOR]

Frequency of intramammary infection and clinical mastitis during the first weeks of lactation, despite high leukocyte counts and high immunoglobulin levels is an immunological paradox. Investigations were made to examine the cause of reduced phagocytic activity by polymorphonuclear leukocytes (PMNL) and macrophages from the 3rd day before to the 21st day after parturition. A significant (P < 0.01) cytotoxic action of colostrum and its fat fraction was noted in vivo on the leukocytes in milk, and in vitro on lymphocytes and PMNL of bovine blood. Apart from the low percentage of living leukocytes, a significantly (P < 0.01) reduced percentage of leukocytes bearing Fc receptors (FcRs) was found. The low percentage of leukocytes bearing FcRs was associated with depressed phagocytic activity of colostral macrophages and PMNL. The results obtained indicate that the cytotoxic and blocking effect of bovine colostrum could seriously affect cell-mediated immunity before parturition and during the first weeks of lactation. Zusammenfassung Zytotoxischer und blockierender Effekt von Rinderkolostrum Trotz hoher Leukozytenzahlen und hoher Ig-Spiegel im Kolostrum kommt es paradoxerweise häufig zu intramammären Infektionen und Mastitiden. Untersucht wurde nun die Beeinflussung der Phagozytoseaktivität von polymorphkernigen Leukozyten (PMNL) und Makrophagen im Zeitraum zwischen dem 3. Tag vor der Geburt und dem 21. Tag nach der Geburt. Nachgewiesen wurde eine signifikante (P < 0,01) zytotoxische Aktivität des Kolostrums und seiner Fettfraktion in vivo auf die Milchleukozyten. Neben der verminderten Prozentzahl lebender Leukozyten wurde auch ein signifikant (P < 0,01) verminderter Prozentsatz von Leukozyten mit Fc-Rezeptoren (FcRs) gefunden. Der geringe Anteil von Fc-Rezeptoren tragender Leukozyten war assoziiert mit einer herabgesetzten Phagozytoseaktivität der Makrophagen und PMNL im Kolostrum. Die Resultate sprechen dafür, daß die zytotoxischen und blockierenden Eigenschaften des Rinderkolostrums die zelluläre Immunität vor der Geburt und in den ersten Wochen der Laktation nachteilig beeinflussen können. [ABSTRACT FROM AUTHOR]

Using a tutorial and expository approach, this paper assesses the performance of some simple, idealized input, output, and compute overlap configurations. Equations are given for one- and two-channel configurations that have one, two, and three partitions of main storage. The objectives of the paper are to gain insight into bounds on system throughput performance and to give equations useful for checking computer simulation. [ABSTRACT FROM AUTHOR]