scholarly journals A Method for Multidisciplinary System Analysis Based on Minimal Feedback Variables

2017 ◽  
Vol 2017 ◽  
pp. 1-14
Author(s):  
Qian Yin ◽  
Yizhong Wu ◽  
Boxing Wang

As modern engineering design usually involves dependence of one discipline on another, multidisciplinary system analysis (MDSA) plays an important role in the multidisciplinary simulation and design optimization on coupled systems. The paper proposes an MDSA method based on minimal feedback variables (MDSA_MF) to enhance the solving efficiency. There are two phases in the method. In phase 1, design structural matrix (DSM) is introduced to represent a coupled system, and each off-diagonal element is denoted by a coupling variable set; then an optimal sequence model is built to obtain a reordered DSM with minimal number of feedback variables. In phase 2, the feedback in the reordered DSM is broken, so that the coupled system is transformed into one directed acyclic graph; then, regarding the inputs depending on the broken feedback as independent variables, a least-squares problem is constructed to minimize the residuals of these independents and corresponding outputs to zero, which means the multidisciplinary consistence is achieved. Besides, the MDSA_MF method is implemented in a multidisciplinary platform called FlowComputer. Several examples of coupled systems are modeled and solved in the platform using several MDSA methods. The results demonstrate that the proposed method could enhance the solving efficiency of coupled systems.

Author(s):  
Abhinav Gupta

This paper presents results from some of the recent studies on seismic analysis of multiply supported piping systems. The seismic responses for an actual feedwater piping system as evaluated from the conventional uncoupled analysis are compared with those obtained from an analysis of the coupled building-piping system. A discussion is also presented on the significance of non-classical damping in such analyses. It is illustrated that the composite modal damping is just another form of classical damping. Consideration of composite modal damping in a coupled analysis can give inaccurate piping responses when the modes of uncoupled systems are nearly tuned. In such systems, the effect of nonclassical damping is quite significant. Since the floor spectra are neither generated nor required in a coupled systems analysis, methods like peak broadening or peak shifting cannot be used directly to account for the effect of uncertainties. Formulations are presented to evaluate the design response from a coupled system analysis by considering the effect of uncertainties in modal properties of uncoupled systems.


2017 ◽  
Vol 32 (4) ◽  
pp. 61-80 ◽  
Author(s):  
Ellen E. Best ◽  
Jennifer Kahle Schafer

ABSTRACT Practitioners routinely note that new staff lack documentation skills, communication skills, and strong Excel skills. Further, new staff report critical-thinking, written and oral communication, teamwork, and project management skills deserve greater emphasis in Master of Accountancy programs. The AICPA's (2014) Model Tax Curriculum suggests that active learning approaches be used to enable students to build communication, critical-thinking, and interpersonal skills. This case uses a realistic corporate tax return preparation experience to address these criticisms by focusing on four main areas: time management, communication, research, and technical skills. The case is divided into two phases. In Phase 1, students review client information, generate requests from the client for missing information, keep a log of hours spent on the project, research ambiguous issues, meet with the project “senior” to obtain guidance, and prepare electronic work papers. In Phase 2, students incorporate feedback from the senior's review of their work papers to make corrections, prepare a corporate tax return, and create a client letter. Student feedback about the project is positive.


Author(s):  
Wen Zhang ◽  
Wenliang Wang ◽  
Hao Wang ◽  
Jiong Tang

A method for dynamic analysis of flexible bladed-disk/shaft coupled systems is presented in this paper. Being independant substructures first, the rigid-disk/shaft and each of the bladed-disk assemblies are analyzed separately in a centrifugal force field by means of the finite element method. Then through a modal synthesis approach the equation of motion for the integral system is derived. In the vibration analysis of the rotating bladed-disk substructure, the geometrically nonlinear deformation is taken into account and the rotationally periodic symmetry is utilized to condense the degrees of freedom into one sector. The final equation of motion for the coupled system involves the degrees of freedom of the shaft and those of only one sector of each of the bladed-disks, thereby reducing the computer storage. Some computational and experimental results are given.


Author(s):  
Srinivasan Sridhar ◽  
Nazmul Kazi ◽  
Indika Kahanda ◽  
Bernadette McCrory

Background: The demand for psychiatry is increasing each year. Limited research has been performed to improve psychiatrist work experience and reduce daily workload using computational methods. There is currently no validated tool or procedure for the mental health transcript annotation process for generating “gold-standard” data. The purpose of this paper was to determine the annotation process for mental health transcripts and how it can be improved to acquire more reliable results considering human factors elements. Method: Three expert clinicians were recruited in this study to evaluate the transcripts. The clinicians were asked to fully annotate two transcripts. An additional five subjects were recruited randomly (aged between 20-40) for this pilot study, which was divided into two phases, phase 1 (annotation without training) and phase 2 (annotation with training) of five transcripts. Kappa statistics were used to measure the inter-rater reliability and accuracy between subjects. Results: The inter-rater reliability between expert clinicians for two transcripts were 0.26 (CI 0.19 to 0.33) and 0.49 (CI 0.42 to 0.57), respectively. In the pilot testing phases, the mean inter-rater reliability between subjects was higher in phase 2 with training transcript (k= 0.35 (CI 0.052 to 0.625)) than in phase 1 without training transcript (k= 0.29 (CI 0.128 to 0.451)). After training, the accuracy percentage among subjects was significantly higher in transcript A (p=0.04) than transcript B (p=0.10). Conclusion: This study focused on understanding the annotation process for mental health transcripts, which will be applied in training machine learning models. Through this exploratory study, the research found appropriate categorical labels that should be included for transcripts annotation, and the importance of training the subjects. Contributions of this case study will help the psychiatric clinicians and researchers in implementing the recommended data collection process to develop a more accurate artificial intelligence model for fully- or semi-automated transcript annotation.


2014 ◽  
Vol 36 (5) ◽  
pp. 583-604 ◽  
Author(s):  
Julie Zide ◽  
Ben Elman ◽  
Comila Shahani-Denning

Purpose – The purpose of this paper is to identify the elements of a LinkedIn profile that hiring professionals focus on most, and then examine LinkedIn profiles in terms of these identified elements across different industries. Design/methodology/approach – The methodology was comprised of two phases. In the first phase, researchers interviewed hiring professionals to determine their usage of LinkedIn. In the second phase, LinkedIn group member profiles from three industries – HR, sales/marketing and industrial/organizational (I/O) psychology – were compared on the 21 variables identified in Phase 1 (n=288). Findings – χ2 and ANOVA tests showed significant differences with respect to ten of the LinkedIn variables in how people presented themselves across the three groups. There were also several gender differences found. Research limitations/implications – A general limitation was the use of a qualitative research approach. A limitation of Phase 1 was that only a small sample of New York City-based hiring professionals was interviewed. Perhaps a wider, more diverse sample would have yielded different variables. In terms of Phase 2, it is possible that just utilizing the second connections of the researchers limited the generalizability of findings. Practical implications – User unwillingness to fully complete the LinkedIn profile suggests that it may not have replaced the traditional resume yet. Sales/marketing professionals were more likely than HR and I/O psychology professionals to complete multiple aspects of a LinkedIn profile. Women were also less likely than men to provide personal information on their profiles. Originality/value – Most of the empirical research on social networking sites has focussed on Facebook, a non-professional site. This is, from the knowledge, the first study that systematically examined the manner in which people present themselves on LinkedIn – the most popular professional site used by applicants and recruiters worldwide.


1999 ◽  
Vol 77 (11) ◽  
pp. 1810-1812 ◽  
Author(s):  
Alex D Bain

Strongly coupled spin systems provide many curious and interesting effects in NMR spectra, one of which is the presence of unexpected (from a first-order viewpoint) lines. A physical reason is given for the presence of these combination lines. The X part of the spectrum of an ABX spin system is analysed as an example. For an ABX system, it is well known that the AB nuclei give a spectrum consisting of two AB-type spectra, corresponding to the two orientations of the X nucleus. It can also be shown that the X part of the spectrum corresponds to the X nucleus undergoing a transition in the presence of an AB-like spin system. For weakly coupled systems, the four observed lines correspond to the four different orientations of the A and B nuclei. For a strongly coupled system, two additional lines may appear, the combination lines. The resulting six lines correspond to the four spin orientations, plus the two zero-quantum transitions. It is shown that these six lines are such that there is no net excitation of the AB-like spin system associated with the X transitions. There is no AB coherence created directly by a pulse applied to X. AB coherence is created as the system evolves, and this is responsible for many of the curious effects. This is shown to be true for all spin sub-systems, which are weakly coupled to a strongly coupled sub-system.Key words: NMR, strong coupling, second-order spectra, ABX spin system, combination lines, spectral analysis.


2020 ◽  
Vol 12 (10) ◽  
pp. 1246-1256
Author(s):  
Bonawentura Kochel

The coupled uniform sequential reaction systems (CUSERS) model, which allows for determining the structure of signaling pathways with incomplete information from the temporal patterns of their components, was applied to the experimental records of activities of TLR4 downstream species IKK and NF-κB in LPS-stimulated wild-type (WT), MyD88-deficient and TRIF-deficient macrophages. New signaling pathways targeting IKK were revealed in MyD88-deficient and TRIF-deficient macrophages, and shown to be described by the coupled systems formed by 3- and 5-component or 5- and 10-component pathways, respectively. By comparing the temporal pattern of IKK in WT macrophages with those in MyD88-deficient and TRIF-deficient macrophages, two new signaling pathways, which were absent in the above defective macrophages, were found and described by a system formed by coupling 9- and 10-component pathways. As a direct consequence of the above findings, a coupled system composed of six different 3-, 5-, 5-, 9-, 10- and 10-component pathways targeting IKK and describing its temporal pattern, IKK(f), in WT macrophages was constructed. This system significantly modifies the canonical NF-κB signaling by introducing novel pathways of IKK activation. The expression of nuclear NF-κB in WT macrophages was found to depend on two different signaling pathways and to be modelled by a coupled system composed of 1- and 4-component or 2- and 8-component pathways, in dependence on sampling frequencies used in different experiments. From the three-modal NF-κB(t) temporal pattern in LPS-stimulated WT fibroblasts, three 1-, 12- and 17-component signaling pathways targeting nuclear NF-κB were determined.


Author(s):  
Moeini Babak ◽  
Barati Majid ◽  
Heidarimoghadam Rashid ◽  
Tapak Leili ◽  
Parsamajd Shahryar

Inadequate health literacy decreases physical activity. This study aimed to develop and examine psychometrics of physical activity health literacy in Iranian older adults. This methodological work was conducted in two phases. Phase 1 consisted of extensive studies review and qualitative study to extract and design the items. The psychometrics were measured in Phase 2 included content, faceconstruct validities, reliability, and stability. The collected data were analyzed in SPSS (version 25.0) and AMOS (version 24.0). The results of the exploratory factor analysis showed four factors— information evaluation, reading skill, perception, and decision making—and used information that explained 70.08% of the variance. The model’s fitness was supported by confirmatory factor analysis. Internal consistency based on Cronbach’s alpha was .89 with composite reliability >0.85. Stability was confirmed through the test–retest method and intraclass correlation coefficient (.89–1). Psychometrics of physical activity health literacy in Iranian older adults supported validity and reliability of the tool.


2014 ◽  
Vol 71 (8) ◽  
pp. 2859-2877 ◽  
Author(s):  
Weixin Xu ◽  
Steven A. Rutledge

Abstract This study investigates the convective population and environmental conditions during three MJO events over the central Indian Ocean in late 2011 using measurements collected from the Research Vessel (R/V) Roger Revelle deployed in Dynamics of the MJO (DYNAMO). Radar-based rainfall estimates from the Revelle C-band radar are first placed in the context of larger-scale Tropical Rainfall Measuring Mission (TRMM) rainfall data to demonstrate that the reduced Revelle radar range captured the MJO convective evolution. Time series analysis and MJO phase-based composites of Revelle measurements both support the “recharge–discharge” MJO theory. Time series of echo-top heights indicate that convective deepening during the MJO onset occurs over a 12–16-day period. Composite statistics show evident recharging–discharging features in convection and the environment. Population of shallow/isolated convective cells, SST, CAPE, and the lower-tropospheric moisture increase (recharge) substantially approximately two to three phases prior to the MJO onset. Deep and intense convection and lightning peak in phase 1 when the sea surface temperature and CAPE are near maximum values. However, cells in this phase are not well organized and produce little stratiform rain, possibly owing to reduced shear and a relatively dry upper troposphere. The presence of deep convection leads the mid- to upper-tropospheric humidity by one to two phases, suggesting its role in moistening these levels. During the MJO onset (i.e., phase 2), the mid- to upper troposphere becomes very moist, and precipitation, radar echo-top heights, and the mesoscale extent of precipitation all increase and obtain peak values. Persistent heavy precipitation in these active periods helps reduce the SST and dry/stabilize (or discharge) the atmosphere.


Author(s):  
Ariela Araujo Fonseca ◽  
Yovanka Pérez Ginoris ◽  
Norma Mendes Pinheiro Gontijo ◽  
Marco Antonio Almeida de Souza

Biological processes are the most widespread methods for wastewater treatment. However, they are limited in their ability to degrade toxic and refractory pollutants, contaminants that electrochemical processes can remove. Therefore, this research explored the possibility of treating sewage by an anaerobic biological process followed by an aerobic system integrated to an electrolytic process. Three sequential batch reactors were operated in an automated way. Each of three reactors represented a process: aerobic biological treatment (BR); electrolytic treatment (ER); and a combination of both, the bio electrolytic reactor (BER). Two phases were ran with different electrodes: (Phase 1) stainless steel and (Phase 2) graphite. The electric current was varied from 0.001 to 0.100 A. COD, TS, SS, turbidity, and the zooplankton community were monitored. The highest organic matter removal efficiencies were 86%, 79% and 87% for BR, ER and BER, respectively. The best weekly BER efficiencies for COD removal were 90% and 98%, with current densities of 0.27 A/m2 (Phase 1) and 0.05 A/m2 (Phase 2). The main conclusions about bio electrolytic process were: (1) it did not achieve organic matter removal high enough to justify its application; (2) inert electrodes are the more indicated; and (3) the zooplankton community was affected by the electric current.


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