Optimal selection of soft sensor inputs for batch distillation columns using principal component analysis

In this paper, a novel methodology based on principal component analysis (PCA) is proposed to select the most suitable secondary process variables to be used as soft sensor inputs. In the proposed approach, a matrix is defined that measures the instantaneous sensitivity of each secondary variable to the primary variables to be estimated. The most sensitive secondary variables are then extracted from this matrix by exploiting the properties of PCA, and they are used as input variables for the development of a regression model suitable for on-line implementation.This method has been evaluated by developing a soft sensor that uses temperature measurements and a process regression model to estimate on-line the product compositions for a simulated batch distillation process. The identification of the optimal soft sensor inputs for this case study has been discussed with respect to the definition of the sensitivity matrix, the data sampling interval, the presence of measurement noise, and the size of the input set. The simulation results demonstrate that the proposed approach can effectively identify the size and configuration of the input set that leads to the optimal estimation performance of the soft sensor.     

Object‐oriented design patterns for debugging heterogeneous languages and virtual machines

Debugging multi‐language software systems requires examining and executing these systems at multiple levels of abstraction. Embedded systems, for example, often comprise a mix of assembly language device drivers and C language control code. Embedded systems increasingly utilize Java to support dynamic loading and run‐time reconfiguration. The RTEEM (Research version of the Tcl Environment for Extensible Modeling) debugger employs three design patterns in solving the problems of multi‐language embedded system debugging. The Reflective virtual machine (VM) pattern models a language‐neutral virtual machine abstraction, with language‐specific interfaces extending this abstraction. Reflection allows a debugger to inspect and control a target VM. The Chain of Responsibility is a classic pattern used to arrange language‐specific debugger command interpreters in a delegation chain. All interpreters share a single command syntax, but each interpreter adapts commands to its language abstraction by interacting with its language‐specific VM view. Composite is another classic pattern, used to combine objects into tree structures. RTEEM employs it to aggregate VM debugger chains into a hierarchy that supports uniform command syntax for debugging threads, processes, multiprocessor systems, and compositions of these entities. This paper illustrates how combining two classic design patterns with the VM abstraction as a pattern results in an architecture that is powerful and flexible in adapting to the debugging needs of heterogeneous, distributed embedded systems. Copyright © 2004 John Wiley & Sons, Ltd.     

Do early talkers become early readers? Linguistic precocity, preschool language, and emergent literacy.

25 children, selected for verbal precocity at 20 mo of age, participated in a longitudinal study investigating predictors of later language and literacy skills. Although children remained verbally precocious, there was a low incidence of precocious reading. Exposure to instruction in letter names and sounds was a significant predictor of children's knowledge of print conventions, invented spelling, and phonological awareness at age 4? yrs. Frequency of story reading in the home and child engagement in a story reading episode at age 24 mo were significant predictors of children's language ability at age 2? yrs and 4? yrs and knowledge of print conventions at age 4? yrs. It is concluded that story reading with parents as well as literacy instruction contributes to the development of emergent literacy in verbally precocious children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial memory in pigeons on a four-arm radial maze.

Examined spatial memory in 6, 8-arm maze experienced pigeons, using a 4-arm radial maze. The maze arms were spaced at 90° intervals, extending radially from a central choice area. Ss were forced into 3 arms, then permitted 2 choices to enter the remaining arm. Five Ss chose accurately (90% correct) with delays of 5 min or less, their choices depended on extramaze cues, and the food in the target arm provided no essential cues. After an incorrect 1st choice, Ss' 2nd choices were more accurate than chance. Data suggest that, while spatial memory has many similar characteristics in rats and pigeons, pigeon spatial memory appears less durable. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Diagnostic value of antibodies to filaggrin in rheumatoid arthritis

OBJECTIVE: To determine the prevalence of antibodies to filaggrin in a cross sectional sample of patients with rheumatoid arthritis (RA). METHODS: Filaggrin from human skin was either extracted with 0.05% Nonidet P-40 and then partially purified by precipitating in ethanol and resuspending in water (Nonidet preparation) or extracted with 9 M urea and then purified by sequential fractionation on a DEAE Sephadex column and on a strong cation exchange column (purified preparation). Antibodies to filaggrin were detected using immunoblotting techniques with sera diluted 1:50. Antikeratin antibodies (AKA) were detected using indirect immunofluorescence microscopy on sections of rat esophagus. RESULTS: Antibodies to filaggrin were detected in 5 of 30 sera of patients with RA using filaggrin from the Nonidet preparation and 6 of 49 sera using filaggrin from the purified preparation. AKA were detected in 13 of 40 sera. A positive correlation existed between the presence of AKA and the presence of antibodies to filaggrin using the purified preparation (p=0.017). CONCLUSION: These data indicate that the reactivity of RA sera with filaggrin is not identical to the presence of AKA and is variable depending upon the preparation of filaggrin used. The diagnostic value of antibodies to filaggrin remains to be proven.     

Thrifty execution of task pipelines

Summary A sequence of tasks that must be performed on a sequential database can be scheduled in various ways. Schedules will differ with respect to the number of accesses made to peripheral storage devices and the amount of memory space consumed by buffers. Buffer requirements are discussed for task schedules that avoid accesses to peripherals storing the sequential database. The relationship between certain thrifty scheduling policies and loop jamming, a standard code optimization technique, is also identified. Application to UNIX pipelines and to file processing is discussed.This work is supported in part by NSF Grant MCS-8003340 and MCS-8103605. Schneider is also supported by a Faculty Development Grant from IBM Corporation     

Pathological findings in human autoimmune lymphoproliferative syndrome

The defects in lymphocyte apoptosis that underlie the autoimmune lymphoproliferative syndrome (ALPS) are usually attributable to inherited mutations of the CD95 (Fas) gene. In this report, we present the histopathological and immunophenotypic features seen in the lymph nodes (n = 16), peripheral blood (n = 10), bone marrow (n = 2), spleen (n = 3), and liver (n = 2) from 10 patients with ALPS. Lymph nodes showed marked paracortical hyperplasia. Interfollicular areas were expanded and populated by T cell receptor-alphabeta CD3+ CD4-CD8- (double-negative, DN) T cells that were negative for CD45RO. CD45RA+ T cells were increased in all cases studied. The paracortical infiltrate was a result of both reduced apoptosis and increased proliferation, as measured by in situ detection of DNA fragmentation and staining with MIB-1, respectively. The paracortical proliferation may be extensive enough to suggest a diagnosis of malignant lymphoma. Many of the paracortical lymphocytes expressed markers associated with cytotoxicity, such as perforin, TIA-1, and CD57. CD25 was negative. In addition, most lymph nodes exhibited florid follicular hyperplasia, often with focal progressive transformation of germinal centers; in some cases, follicular involution was seen. A polyclonal plasmacytosis also was present. The spleens were markedly enlarged, more than 10 times normal size. There was expansion of both white pulp and red pulp, with increased DN T cells. DN T cells also were observed in liver biopsies exhibiting portal triaditis. In the peripheral blood, the T cells showed increased expression of HLA-DR and CD57 but not CD25. CD45RA+ T cells were increased in the four cases studied. Polyclonal B cell lymphocytosis with expansion of CD5+ B cells was a characteristic finding. Taken together, the histopathological and immunophenotypic findings, particularly in lymph nodes and peripheral blood, are sufficiently distinctive to suggest a diagnosis of ALPS. Of note, two affected family members of one proband developed lymphoma (T-cell-rich B-cell lymphoma and nodular lymphocyte predominance Hodgkin's disease, respectively).     

Comparison of Solid-Liquid and Liquid-Liquid Mass Transfer

Mass transfer from solutions of m-acetotoluide, phenacetin and salicylamide into a stationary solvent, water, was studied. A sharp concentration jump was found at the leading solute front for all three liquid-liquid systmes. A comparison was made between the mass transferred in solid-liquid and liquid-liquid systems. The dissolution of m-acetotoluide, phenacetin and salicylamide was compared with mass transfer of solute from solutions with concentrations C_i, 2C_i and C_s into the pure solvent. In all cases, the amount dissolved from the solid was approximated by the C_i or the 2C_i-solvent system with the amount transferred in the C_s-solvent system approximately 100 fold greater than was dissolved from the solid. It was concluded that a concentration much less than saturation exists at the solid-liquid interface and that dissolution of the three compounds studied is controlled by the rate of solvent interaction at the solid surface.     

Undergraduate students and the history of psychology.

Presents data on undergraduates' sentiments about the history of psychology, based on surveys in the early 1960s (e.g., R. D. Nance [1961]) and the early 1970s. Undergraduates preferred emphasis on contemporary and recent events, although they found the study of history somewhat useful. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chemical oxygen demand of some nitrogenous heterocyclic compounds

Chemical oxygen demands of fourteen nitrogenous compounds were determined by the dichromate method. Only pyridine and its derivatives were resistant to oxidation. Heterocyclic compounds containing one atom of nitrogen in a molecule, e.g. quinoline, pyrrole, proline, and indole were 90–100 per cent oxidized. Nitrogen is split off these compounds as NH₃. Heterocyclic compounds containing two or more atoms of nitrogen in a molecule are also easily oxidized. However, only a part of the nitrogen is split off as NH₃. On the basis of the results obtained it is possible to make the following generalization: nitrogen in amino groups is split off mostly as NH₃; quinoline, pyrrole, pyrrolidine, and indole nitrogen is split off as NH₃; from imidazole and pyrimidine rings, one atom of nitrogen is split off as NH₃ and one as N₂; from the purine configuration, two atoms of nitrogen are split off as NH₃ and two atoms as N₂; from isoalloxazine, three atoms of nitrogen are split off as NH₃ and one as N₂.