Visual Depiction of Decision Statements: What is Best for Programmers and Non-Programmers?

This paper reports the results of two experiments investigating differences in comprehensibility of textual and graphical notations for representing decision statements. The first experiment was a replication of a prior experiment that found textual notations to be better than particular graphical notations. After replicating this study, two other hypotheses were investigated in a second experiment. Our first claim is that graphics may be better for technical, non-programmers than they are for programmers because of the great amount of experience that programmers have with textual notations in programming languages. The second is that modifications to graphical forms may improve their usefulness. The results support both of these hypotheses.     

Using Evaluation to Shape ITS Design: Results and Experiences with SQL-Tutor

This paper presents the results of three evaluation studies performed during 1998 and 1999 on SQL-Tutor, an intelligent tutoring system for the SQL database language. We have evaluated the system in the context of genuine courses, and used the results to further refine the system. The main goal of our research has been the exploration and extension of Constraint-Based Modeling (CBM), a student modeling approach proposed by Ohlsson (1994). SQL-Tutor provided us with experiences of using CBM, and we used it to extend the approach in several important ways. The main goal of all three evaluation studies was to determine how well CBM supported student learning. We have obtained positive results. The students who learnt with SQL-Tutor in the first study performed significantly better than those who did not when assessed by a subsequent classroom examination. Furthermore, the analysis of students' learning shows that CBM has a sound psychological foundation.Besides the evaluation of CBM, we also evaluated the improvements in terms of student assessments of the usefulness of the system and evaluated various techniques used in SQL-Tutor. In the second study, we evaluated the effectiveness of feedback provided to the students. This study showed that high-level advice is most beneficial to students' learning. The focus of the third study was different. We extended CBM to support long-term modeling of student knowledge, and used this extension to develop an adaptive problem-selection strategy. The study revealed the benefits of this strategy in comparison with a simple heuristic strategy. We also reflect on our experiences in evaluating SQL-Tutor.     

Orthogonally polarized RF optical single sideband generation with integrated ring resonators

We review recent work on narrowband orthogonally polarized optical RF single sideband generators as well as dualchannel equalization,both based on high-Q integrated ring resonators.The devices operate in the optical telecommunications C-band and enable RF operation over a range of either fixed or thermally tuneable frequencies.They operate via TE/TM mode birefringence in the resonator.We achieve a very large dynamic tuning range of over 55 dB for both the optical carrier-to-sideband ratio and the dual-channel RF equalization for both the fixed and tunable devices.     

Hitting a moving target: a process model of information systems control change

Controls are widely regarded as a key factor in driving high performing organisational processes. However, because of ongoing changes within information systems (IS) processes, control modifications are commonly required in order to maintain performance levels. Although past research recognises the ongoing benefits derived from successful control changes, there is a limited understanding of the actual steps taken by organisations, particularly with regard to avoiding negative performance implications such as process delays or employee resistance. This research draws on empirical data from six case studies to propose a new process model that depicts the interconnected steps involved in control changes. Our findings suggest that the sources of IS control change may be more diverse than most past research suggests and that control changes within non‐project‐oriented processes (e.g. enterprise architecture) present additional challenges in comparison to project‐oriented processes (e.g. systems development). Insights from this research can aid practitioners in streamlining control changes as a means to improve effectiveness, whilst also contributing to research by uncovering an enhanced understanding of why and how control changes are made in IS processes.     

Oxidative Hydrophenylation of Ethylene Using a Cationic Ru(II) Catalyst: Styrene Production with Ethylene as the Oxidant

The complex [(MeOTTM)Ru(P(OCH₂)₃CEt)(NCMe)Ph][BAr′₄] (MeOTMM=4,4’,4’’-(methoxymethanetriyl)-tris(1-benzyl-1H-1,2,3-triazole), BAr′₄=tetrakis[3,5-bis(trifluoromethyl)phenyl]borate) is used to catalyze the hydrophenylation of ethylene to produce styrene and ethylbenzene. The selectivity of styrene versus ethylbenzene varies as a function of ethylene pressure, and replacing the MeOTTM ligand with tris(1-phenyl-1H-1,2,3-triazol-4-yl)methanol reduces the selectivity toward styrene. For styrene production ethylene serves as the oxidant to produce ethane, as determined by both ¹H NMR spectroscopy and GC-MS. The Ru(III/II) potentials of [(MeOTTM)Ru[P(OCH₂)₃CEt](NCMe)Ph][BAr′₄] (0.86 V) and [(HC(pz⁵)₃)Ru[P(OCH₂)₃CEt](NCMe)Ph][BAr′₄] (0.82 V) (HC(pz⁵)₃=tris(5-methyl-pyrazolyl)methane) are nearly identical. Since catalytic conversion of ethylene and benzene by [(HC(pz⁵)₃)Ru[P(OCH₂)₃CEt](NCMe)Ph][BAr′₄] is known to selectively produce ethylbenzene, the formation of styrene using [(MeOTTM)Ru[P(OCH₂)₃CEt](NCMe)Ph][BAr′₄] is attributed to the substituents on the triazole rings of the MeOTTM ligand.     

How dense are cylindrical brushes grafted from a multifunctional macroinitiator?

A series of cylindrical brushes with poly(methyl methacrylate) (PMMA) and poly(n-butyl acrylate) (PBA) side chains of different lengths was studied to understand the grafting density of brush molecules prepared by the ‘grafting from’ approach. Molecules with PMMA side chains were prepared by grafting MMA from a multifunctional macroinitiator, poly(2-(2-bromoisobutyryloxy)ethyl methacrylate). Molecules with PBA side chains were prepared with poly(2-(2-bromopropionyloxy)ethyl methacrylate) as a macroinitiator. Analysis of the detached side chains showed an incomplete initiation process resulting in longer side chains than expected for complete initiation. Limited initiation (40-80%) was also observed for short PMMA chains using a low molar mass initiator ethyl 2-bromoisobutyrate with CuCl catalyst systems. The lower initiation efficiency was confirmed via visualization of individual molecules by atomic force microscopy. The larger distance between adsorbed brush molecules was consistent with <50% initiation efficiency.     

RESTful API in Life Science Research Systems and Data Integration Challenges： Linking Metabolic Pathway,Metabolic Network,Gene and Publication

Translational science research development requires life sciences researchers to update their concept on systems integration and data integration. The RESTful API has proven to be very useful in integrating the massive amount of data and tools. This work presents an approach for biological systems analysis based on the semantic web and RESTful API. The integration of this approach in the BioExtract Server engine as a WMS （workflow management system） allows us to apply our work to the linking of several biological levels （metabolic pathway, metabolic network model, genes and publications）. This work shows how HPC infrastructure and RESTful API can be an opportunity in Systems Biology and life science research challenges. We present a use case in BioExtract server as an integrated workflow management system. The use case shows how we can extract data to build a mathematical model for a specific biological system. The two workflow examples provided in this work enhance the flexibility in the workflow for reusability. Then any other researcher can customize the same workflow for different gene name or biological process.     

Comparison of polyethylene glycol and diethylene glycol distearate embedding methods for the preservation of fungal cytoskeletons

Hyphae of the fungus Basidiobolus magnus were embedded in extractable polyethylene glycol (PEG) or diethylene glycol distearate (DGD) to prepare embedment-free sections in order to seek components of the cytoskeleton that may be obscured in epoxy-embedded sections. All methods showed that hyphae possess an intricate filamentous matrix, which is apparently unoriented. However, the appearance of the cytoskeleton depended on the embedding medium, the solvent used during embedding, and whether cells were fixed by conventional fixation or freeze-substitution. PEG proved to be the best embedding medium for fungal cells because DGD caused cell shrinkage and produced a more lamellar than filamentous matrix. Also, the cytoskeletal filaments were clearer in freeze-substituted cells than in conventionally-fixed cells. Since we failed to find microtubules in the embedment-free sections, we re-embedded cells in Epon to discern whether microtubules or other cytoplasmic components had changed. Neither PEG nor DGD adequately preserved microtubules as compared to regular Epon-embedded sections, and other cellular structures were significantly altered. Therefore, alternative methods need to be employed to further characterize fungal cytoskeletons.     

Nonintrusive frequency analysis for variable pairing on a distillation column

This paper describes a nonintrusive plant analysis technique for variable pairing that relies on power spectrum frequency analysis. The development of the method is described and guidelines for the implementation of the method are presented. Information gathered from the frequency analysis is used in variable pairing to ensure minimal impacts from unmeasured disturbances. Specifically, the nested epsilon decomposition method for variable pairing is used. This nonintrusive analysis method is implemented on a pilot plant distillation column. The results of the pilot plant test are used in the decoupling of a multiloop control system.     

Statistical Algorithms for Designing Geophysical Surveys to Detect UXO Target Areas

The U.S. Department of Defense is in the process of assessing and remediating closed, transferred, and transferring military training ranges across the United States. Many of these sites have areas that are known to contain unexploded ordnance (UXO). Other sites or portions of sites are not expected to contain UXO, but some verification of this expectation using geophysical surveys is needed. Many sites are so large that it is often impractical and/or cost prohibitive to perform surveys over 100% of the site. In such cases, it is particularly important to be explicit about the performance required of the surveys. This article presents the statistical algorithms developed to support the design of geophysical surveys along transects (swaths) to find target areas (TAs) of anomalous geophysical readings that may indicate the presence of UXO. The algorithms described here determine (1) the spacing between transects that should be used for the surveys to achieve a specified probability of traversing the TA, (2) the probability of both traversing and detecting a TA of anomalous geophysical readings when the spatial density of anomalies within the TA is either uniform (unchanging over space) or has a bivariate normal distribution, and (3) the probability that a TA exists when it was not found by surveying along transects. These algorithms have been implemented in the Visual Sample Plan (VSP) software to develop cost-effective transect survey designs that meet performance objectives.