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A technology review and assessment of modeling and analysis efforts underway in support of a safe return to flight of the thermal protection system (TPS) for the Space Shuttle external tank (ET) are summarized. This review and assessment effort focuses on the structural modeling and analysis practices employed for ET TPS foam design and analysis and on identifying analysis capabilities needed in the short-term and long-term. The current understanding of the relationship between complex flight environments and ET TPS foam failure modes are reviewed as they relate to modeling and analysis. A literature review on modeling and analysis of TPS foam material systems is also presented. Finally, a review of modeling and analysis tools employed in the Space Shuttle Program is presented for the ET TPS acreage and close-out foam regions. This review includes existing simplified engineering analysis tools are well as finite element analysis procedures.

Airframe noise is a significant part of the overall noise of transport aircraft during the approach and landing phases of flight. Airframe noise reduction is currently emphasized under the Environmentally Responsible Aviation (ERA) and Fixed Wing (FW) Project goals of NASA. A promising concept for trailing-edge-flap noise reduction is a flexible structural element or link that connects the side edges of the deployable flap to the adjacent main-wing structure. The proposed solution is distinguished by minimization of the span-wise extent of the structural link, thereby minimizing the aerodynamic load on the link structure at the expense of increased deformation requirement. Development of such a flexible structural link necessitated application of hyperelastic materials, atypical structural configurations and novel interface hardware. The resulting highly-deformable structural concept was termed the FLEXible Side Edge Link (FLEXSEL) concept. Prediction of atypical elastomeric deformation responses from detailed structural analysis was essential for evaluating feasible concepts that met the design constraints. The focus of this paper is to describe the many challenges encountered with hyperelastic finite element modeling and the nonlinear structural analysis of evolving FLEXSEL concepts. Detailed herein is the nonlinear analysis of FLEXSEL concepts that emerged during the project which include solid-section, foamcore, hollow, extended-span and pre-stressed concepts. Coupon-level analysis performed on elastomeric interface joints, which form a part of the FLEXSEL topology development, are also presented.

Gasdynamic environments applied to the turbine blades and nozzles of the HPFTP and HPOTP were analyzed. Centrifugal loads were applied to blades to account for the pump rotation of FPL and 115 percent RPL. The computer models used in the blade analysis with results presented in the form of temperature and stress contour plots are described. Similar information is given for the nozzles.

This article is from PLoS ONE , volume 9 . Abstract Background: Exhaled aerosol patterns, also called aerosol fingerprints, provide clues to the health of the lung and can be used to detect disease-modified airway structures. The key is how to decode the exhaled aerosol fingerprints and retrieve the lung structural information for a non-invasive identification of respiratory diseases. Objective and Methods: In this study, a CFD-fractal analysis method was developed to quantify exhaled aerosol fingerprints and applied it to one benign and three malign conditions: a tracheal carina tumor, a bronchial tumor, and asthma. Respirations of tracer aerosols of 1 µm at a flow rate of 30 L/min were simulated, with exhaled distributions recorded at the mouth. Large eddy simulations and a Lagrangian tracking approach were used to simulate respiratory airflows and aerosol dynamics. Aerosol morphometric measures such as concentration disparity, spatial distributions, and fractal analysis were applied to distinguish various exhaled aerosol patterns. Findings: Utilizing physiology-based modeling, we demonstrated substantial differences in exhaled aerosol distributions among normal and pathological airways, which were suggestive of the disease location and extent. With fractal analysis, we also demonstrated that exhaled aerosol patterns exhibited fractal behavior in both the entire image and selected regions of interest. Each exhaled aerosol fingerprint exhibited distinct pattern parameters such as spatial probability, fractal dimension, lacunarity, and multifractal spectrum. Furthermore, a correlation of the diseased location and exhaled aerosol spatial distribution was established for asthma. Conclusion: Aerosol-fingerprint-based breath tests disclose clues about the site and severity of lung diseases and appear to be sensitive enough to be a practical tool for diagnosis and prognosis of respiratory diseases with structural abnormalities.

The objective of this study is to investigate structural shadow zones encountered in shipbuilding design using the I-DEAS (Integrated Design Engineering Analysis Software) software. The term 'shadow zone' refers to areas of low stress concentrations that are caused by lines of stress bending around structural discontinuities. Two ship design situations frequently encountered that result in shadow zones are hull girder penetrations and short structural longitudinal bulkheads. In both of these situations, a long-used rule of thumb is to construct a line with a slope of 1:4 originating from the. discontinuity that encompasses the area of low stress. The material within this line is then considered ineffective when computing the section modulus. This can prove to be expensive. However, powerful finite element analysis software is readily available that can analyze the shadow zones in greater detail and possibly minimize the area considered ineffective. This study uses the I-DEAS software to develop finite element models of the cited design situations for a U.S. Navy Frigate, FFG-7 class of ship. It conducts a static structural linear analysis of the ship balanced on a trochoidal wave of height 1.1 VL. The results generated in this study validate the rule of thumb in both situations.

The development of a wavelet-based feature extraction technique specifically targeting FOD-event induced vibration signal changes in gas turbine engines is described. The technique performs wavelet analysis of accelerometer signals from specified locations on the engine and is shown to be robust in the presence of significant process and sensor noise. It is envisioned that the technique will be combined with Kalman filter thermal/health parameter estimation for FOD-event detection via information fusion from these (and perhaps other) sources. Due to the lack of high-frequency FOD-event test data in the open literature, a reduced-order turbofan structural model (ROM) was synthesized from a finite element model modal analysis to support the investigation. In addition to providing test data for algorithm development, the ROM is used to determine the optimal sensor location for FOD-event detection. In the presence of significant noise, precise location of the FOD event in time was obtained using the developed wavelet-based feature.

Thesis advisor, Charles N. Calvano

New modeling and analysis techniques have been developed for predicting the dynamic behavior of the Next Generation Space Telescope (NGST) sunshield. The sunshield consists of multiple layers of pretensioned, thin-film membranes supported by deployable booms. Modeling the structural dynamic behavior of the sunshield is a challenging aspect of the problem due to the effects of membrane wrinkling. A finite element model of the sunshield was developed using an approximate engineering approach, the cable network method, to account for membrane wrinkling effects. Ground testing of a one-tenth scale model of the NGST sunshield were carried out to provide data for validating the analytical model. A series of analyses were performed to predict the behavior of the sunshield under the ground test conditions. Modal analyses were performed to predict the frequencies and mode shapes of the test article and transient response analyses were completed to simulate impulse excitation tests. Comparison was made between analytical predictions and test measurements for the dynamic behavior of the sunshield. In general, the results show good agreement with the analytical model correctly predicting the approximate frequency and mode shapes for the significant structural modes.

This project will aim to examine a potential moderator effect of socioeconomic status in the relation between teacher social support and sense of belonging to school. We will base our analyses on a nationally representative sample of 15-year-old French students. This sample will be extracted from the Programme for Internationnal Student Assesment (PISA) 2018 which is a survey lead by member countries of the Organisation for Economic Co-operation and Development (OECD) including many invited countries. The idea for this project emerged from PISA's observations on French students concerning, on the one hand, the large performance gap between the most advantaged (high SES) and the most disadvantaged (low SES) students and, on the other hand, their low level of sense of belonging to school.

This article is from BMC Public Health , volume 14 . Abstract Background: Although studies suggest the relevance of intimate partner violence (IPV) and other health-related social characteristics as risk factors for postpartum mental health, literature lacks evidence about how these are effectively connected. This study thus aims to explore how socio-economic position, maternal age, household and marital arrangements, general stressors, alcohol misuse and illicit drug abuse, and especially psychological and physical IPV relate in a framework leading to postpartum common mental disorder (CMD). Methods: The study was carried out in five primary health care units of Rio de Janeiro, Brazil, and included 810 randomly selected mothers of children up to five postpartum months waiting for pediatric visits. The postulated pathways between exposures and outcome were based on literature evidence and were further examined using structural equation models. Results: Direct pathways to postpartum CMD arose from a latent variable depicting socio-economic position, a general stressors score, and both IPV variables. Notably, the effect of psychological IPV on postpartum CMD ran partly through physical IPV. The effect of teenage pregnancy, conjugal instability and maternal burden apparently happens solely through substance use, be it alcohol misuse, illicit drug abuse or both in tandem. Moreover, the effect of the latter on CMD seems to be entirely mediated through both types of IPV. Conclusion: Although the theoretical model underlying the analysis still requires in-depth detailing, results of this study may have shed some light on the role of both psychological and physical IPV as part of an intricate network of events leading to postpartum CMD. Health initiatives may want to make use of this knowledge when designing preventive and intervention approaches.

New modeling and analysis techniques have been developed for predicting the dynamic behavior of the Next Generation Space Telescope (NGST) sunshield. The sunshield consists of multiple layers of pretensioned, thin-film membranes supported by deployable booms. Modeling the structural dynamic behavior of the sunshield is a challenging aspect of the problem due to the effects of membrane wrinkling. A finite element model of the sunshield was developed using an approximate engineering approach, the cable network method, to account for membrane wrinkling effects. Ground testing of a one-tenth scale model of the NGST sunshield were carried out to provide data for validating the analytical model. A series of analyses were performed to predict the behavior of the sunshield under the ground test conditions. Modal analyses were performed to predict the frequencies and mode shapes of the test article and transient response analyses were completed to simulate impulse excitation tests. Comparison was made between analytical predictions and test measurements for the dynamic behavior of the sunshield. In general, the results show good agreement with the analytical model correctly predicting the approximate frequency and mode shapes for the significant structural modes.

The development of a wavelet-based feature extraction technique specifically targeting FOD-event induced vibration signal changes in gas turbine engines is described. The technique performs wavelet analysis of accelerometer signals from specified locations on the engine and is shown to be robust in the presence of significant process and sensor noise. It is envisioned that the technique will be combined with Kalman filter thermal/health parameter estimation for FOD-event detection via information fusion from these (and perhaps other) sources. Due to the lack of high-frequency FOD-event test data in the open literature, a reduced-order turbofan structural model (ROM) was synthesized from a finite element model modal analysis to support the investigation. In addition to providing test data for algorithm development, the ROM is used to determine the optimal sensor location for FOD-event detection. In the presence of significant noise, precise location of the FOD event in time was obtained using the developed wavelet-based feature.

Normal modes of the blades and nozzles of the HPFTP and HPOTP are defined and potential driving forces for the blades are identified. The computer models used in blade analyses are described, with results. Similar information is given for the nozzles.

Structural equation modeling (SEM) has been deemed as a proper method when variables contain measurement errors. In contrast, path analysis with composite-scores is preferred for prediction and diagnosis of individuals. While path analysis with composite-scores has been criticized for yielding biased parameter estimates, recent literature pointed out that the population values of parameters in a latent-variable model depend on artificially assigned scales. Consequently, bias in parameter estimates is not a well-grounded concept for models involving latent constructs. This article compares path analysis with composite-scores against SEM with respect to effect size and statistical power in testing the significance of the path coefficients, via the z- or t-statistics. The data come from many sources with various models that are substantively determined. Results show that SEM is not as powerful as path analysis even with equally-weighted-composites. But path analysis with Bartlett-factor- scores and the partial-least-squares approach to SEM perform the best with respect to effect size and power. [This paper will be published in "Behavior Research Methods." Discrepancy between the title of the article and authored paper.]

The objective of this study is to investigate structural shadow zones encountered in shipbuilding design using the I-DEAS (Integrated Design Engineering Analysis Software) software. The term 'shadow zone' refers to areas of low stress concentrations that are caused by lines of stress bending around structural discontinuities. Two ship design situations frequently encountered that result in shadow zones are hull girder penetrations and short structural longitudinal bulkheads. In both of these situations, a long-used rule of thumb is to construct a line with a slope of 1:4 originating from the. discontinuity that encompasses the area of low stress. The material within this line is then considered ineffective when computing the section modulus. This can prove to be expensive. However, powerful finite element analysis software is readily available that can analyze the shadow zones in greater detail and possibly minimize the area considered ineffective. This study uses the I-DEAS software to develop finite element models of the cited design situations for a U.S. Navy Frigate, FFG-7 class of ship. It conducts a static structural linear analysis of the ship balanced on a trochoidal wave of height 1.1 VL. The results generated in this study validate the rule of thumb in both situations

See Wiki page below for details.

See Wiki page below for details.

See Wiki page below for details.

Previous literature suggests a triadic interrelationship between adult attachment, mindfulness, and meaning in life. Yet, to the best of one’s knowledge, no prior studies have linked the 3 variables together. This is the literature gap that the present meta-analysis aims to address. To be able to address this gap and establish a triangular relationship between the 3 variables, a mediation model would need to be established. This would be done through conducting three distinct meta-analyses followed by structural equation modeling to establish the tripartite relationship. The three meta-analyses that have been done are as follows; one looked at previous studies that investigated the relationship between adult attachment and mindfulness, one looked at previous studies that investigated the relationship between adult attachment and meaning in life, and one looked at previous studies that investigated the relationship between mindfulness and meaning in life. Various databases were utilised to collect the previous studies done on the three variables using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The EPHPP’s Quality Assessment Tool for Quantitative Studies was utilised to assess the quality of the included studies. The studies have been imported on Covidence website. JS have screened the studies’ titles and abstracts. The Fisher Z effect size was calculated from the correlation coefficient of each study using this formula (0.5*LN((1+(r))/(1-(r))) and the variance was calculated from the participants’ number of each study using this formula (1/(n-3)) then the effect size and the variance were used to run the final random effect sizes model analysis on SPSS 28 and get the forest plots. One also assessed study heterogeneity by calculating Cochrane’s Q and I2 statistic, assessed if the null-hypothesis can be rejected by running a Z-test, assessed publication bias through Egger’s regression and in case publication bias was indicated, Duval and Tweedie’s (2000) trim and fill technique was done. Finally and most importantly, structural equation modeling will be utilised to establish the mediation models linking the three relationships from the three meta-analyses together. The results from this study would inform the upcoming studies within the PhD program.

The normal-distribution-based likelihood ratio statistic T[subscript ml] = nF[subscript ml] is widely used for power analysis in structural Equation modeling (SEM). In such an analysis, power and sample size are computed by assuming that T[subscript ml] follows a central chi-square distribution under H[subscript 0] and a noncentral chi-square distribution under H[subscript a]. However, with either violation of normality or not a large enough sample size, both empirical and analytical results indicate that the chi-square distribution assumptions are not realistic and consequently methods of power analysis based on such assumptions are not valid. This article describes a Monte Carlo (MC) method for power analysis. A measure of effect size for characterizing the power property of different rescaled statistics is also provided. Robust methods are proposed to increase the power of T[subscript ml] and other statistics. Simulation results show that the MC method reliably controls Type I errors and robust estimation methods effectively increase the power, and their combination is thus recommended for conducting power analysis in SEM.

An existing large data set, the Health and Retirement Study 2000 (HRS 2000) was used to explore the relationship between cognition and other factors for individuals aged 65 and older, with a final sample of 1,610 males and 3,549 females. Using structural equation modeling, the entire model was tested to determine if there were differences in how well the model fit data from both men and women. The influences of direct and indirect contributing factors on cognition were also investigated. Although there were no significant gender differences in the fit of the model for data from this population, future research might study the relationship between cognitive decline and gender within specific age or cultural groups. (Contains 1 table, 3 figures, and 42 references.) (Author/SLD)

A technology review and assessment of modeling and analysis efforts underway in support of a safe return to flight of the thermal protection system (TPS) for the Space Shuttle external tank (ET) are summarized. This review and assessment effort focuses on the structural modeling and analysis practices employed for ET TPS foam design and analysis and on identifying analysis capabilities needed in the short-term and long-term. The current understanding of the relationship between complex flight environments and ET TPS foam failure modes are reviewed as they relate to modeling and analysis. A literature review on modeling and analysis of TPS foam material systems is also presented. Finally, a review of modeling and analysis tools employed in the Space Shuttle Program is presented for the ET TPS acreage and close-out foam regions. This review includes existing simplified engineering analysis tools are well as finite element analysis procedures.

Performance-related effects of system level temperature changes can be a key consideration in the design of many types of optical instruments. This is especially true for space-based imagers, which may require complex thermal control systems to maintain alignment of the optical components. Structural-Thermal-Optical-Performance (STOP) analysis is a multi-disciplinary process that can be used to assess the performance of these optical systems when subjected to the expected design environment. This type of analysis can be very time consuming, which makes it difficult to use as a trade study tool early in the project life cycle. In many cases, only one or two iterations can be performed over the course of a project. This limits the design space to best practices since it may be too difficult, or take too long, to test new concepts analytically. In order to overcome this challenge, automation, and a standard procedure for performing these studies is essential. A methodology was developed within the framework of the Comet software tool that captures the basic inputs, outputs, and processes used in most STOP analyses. This resulted in a generic, reusable analysis template that can be used for design trades for a variety of optical systems. The template captures much of the upfront setup such as meshing, boundary conditions, data transfer, naming conventions, and post-processing, and therefore saves time for each subsequent project. A description of the methodology and the analysis template is presented, and results are described for a simple telescope optical system.

Using meta-analysis to examine the relationships between empathy, moral identity, and prosocial behavior, and develop a structural equation model

This quantitative investigation involved 1,054 pre-service teacher respondents with mean age = 20.21 (SD=3.124). This cross-sectional study gathered data through the creation of four research tools validated and pilot tested. Moreover, three of the research tools (AChavQ, AFilQ, AEngQ) were determined to be of 'excellent' reliability, while one is of 'acceptable' reliability (CogMT). The study purposed to derive a model explaining the possible relationships, mediation or moderation, of language attitude towards Chavacano with ethnicity, cognition towards mother tongue and language attitude toward Filipino and English. The model with "best fit" showed that that language attitude toward Filipino and English has a direct influence on cognition in the mother tongue. In contrast, ethnicity's influence is mediated by language attitude toward Chavacano. The results and findings of this study provide vital information and insights in the implementation of the Mother Tongue Based Education in a multilingual context.

Low pressure fuel turbopump turbine labyrinth send tip rubbing analysis, gas dynamic analysis, and HPFTP blade crack and blade impact are presented.

This thesis examine opportunities for the application of information technology through mathematical modeling and design of a new method of a ship's space monitoring for the support of command decisions during a fire aboard. Thesis analyzes peculiarities of a fire and difficulties inherent in gathering data, particularly the lack of objective information about a fire scale, fire dynamics, and timing of functioning the ship's equipment during an emergency aboard. It was shown that, in a closed compartment, a gas pressure monitoring is a very perspective way of determining a fire scale and its propagation ability. The appropriate models of fire development were created. They were designed in a way of using only those data that were possible to observe during a fire aboard. Depending on availability and quality of current information about the fire, an informative tree of alternative scenarios of the fire hazard analysis and command decisions was developed. Conducted in terms of decision theory concept, formalization of fire-fighting procedure permitted to accomplish structural and cost benefit analysis of the command decisions during a fire aboard. Relevant chronological decision tree diagrams were designed. Structural analysis proved that application of information technology and new method of gas pressure monitoring significantly increases efficiency of command decisions during a fire without considerable additional costs

This effort explores the evolution and characterization of structural cracks in aircraft fuselage structures in which the loads are varying. During flight, an aircraft fuselage skin and structure are subjected to varied cyclic loads, which can cause embedded cracks and other damage features to change their characteristics due to loading effects. The current research uses finite element modeling and experimental techniques to characterize the behavior of cracks under different static loads, with the goal of understanding the interaction of ultrasonic energy with opening-closing crack features. Specimen testing under tensile loads were considered, where crack detection and crack characterization were studied for bonded piezoelectric sensing and guided ultrasonic waves useful in structural health monitoring applications. The results suggest that crack detection and crack sizing accuracy can be impacted by load-induced, crack opening-closure effects, where linear elastic loading of the structure resulted in linear changes in the ultrasonic signal response.

This report documents four critical tasks concerned with the development and implementation of an advanced and novel modeling framework for predicting damage accumulation in composite structures undergoing monotonic and fatigue loadings. The critical tasks that have been completed are: 1. To enhance existing damage models to accurately capture the physics of failure of fiber-reinforced composites. 2. To develop a modeling technique that accurately captures damage accumulation due to cyclic loading. 3. To correlate predictions to experimental results being obtained at the Air Force Research Laboratory. 4. To develop improvements to modeling techniques based on empirical data. The pursuit of these four major tasks produced the methods, data, and results presented in this report. Our activities facilitate reliable assessment of the durability and damage tolerance of composite aircraft in accordance with the strategic needs of the Air Force. In fulfillment of this motive, we engaged in the development of efficient and accurate models to simulate the physical mechanisms of composite failure when subjected to monotonic and cyclic loads.

This article is from BMC Research Notes , volume 5 . Abstract Background: Serine proteases account for over a third of all known proteolytic enzymes; they are involved in a variety of physiological processes and are classified into clans sharing structural homology. The PA clan of endopeptidases is the most abundant and over two thirds of this clan is comprised of the S1 family of serine proteases, which bear the archetypal trypsin fold and have a catalytic triad in the order Histidine, Aspartate, Serine. These proteases have been studied in depth and many three dimensional structures have been experimentally determined. However, these structures mostly consist of bacterial and animal proteases, with a small number of plant and fungal proteases and as yet no structures have been determined for protozoa or archaea. The core structure and active site geometry of these proteases is of interest for many applications. This study investigated the structural properties of different S1 family serine proteases from a diverse range of taxa using molecular modeling techniques. Results: Our predicted models from protozoa, archaea, fungi and plants were combined with the experimentally determined structures of 16 S1 family members and used for analysis of the catalytic core. Amino acid sequences were submitted to SWISS-MODEL for homology-based structure prediction or the LOOPP server for threading-based structure prediction. Predicted models were refined using INSIGHT II and SCRWL and validated against experimental structures. Investigation of secondary structures and electrostatic surface potential was performed using MOLMOL. The structural geometry of the catalytic core shows clear deviations between taxa, but the relative positions of the catalytic triad residues were conserved. Some highly conserved residues potentially contributing to the stability of the structural core were identified. Evolutionary divergence was also exhibited by large variation in secondary structure features outside the core, differences in overall amino acid distribution, and unique surface electrostatic potential patterns between species. Conclusions: Encompassing a wide range of taxa, our structural analysis provides an evolutionary perspective on S1 family serine proteases. Focusing on the common core containing the catalytic site of the enzyme, this analysis is beneficial for future molecular modeling strategies and structural analysis of serine protease models.

This article is from PLoS ONE , volume 9 . Abstract DNA methylation plays a crucial role in development through inheritable gene silencing. Plants possess three types of DNA methyltransferases (MTases), namely Methyltransferase (MET), Chromomethylase (CMT) and Domains Rearranged Methyltransferase (DRM), which maintain methylation at CG, CHG and CHH sites. DNA MTases have not been studied in legumes so far. Here, we report the identification and analysis of putative DNA MTases in five legumes, including chickpea, soybean, pigeonpea, Medicago and Lotus. MTases in legumes could be classified in known MET, CMT, DRM and DNA nucleotide methyltransferases (DNMT2) subfamilies based on their domain organization. First three MTases represent DNA MTases, whereas DNMT2 represents a transfer RNA (tRNA) MTase. Structural comparison of all the MTases in plants with known MTases in mammalian and plant systems have been reported to assign structural features in context of biological functions of these proteins. The structure analysis clearly specified regions crucial for protein-protein interactions and regions important for nucleosome binding in various domains of CMT and MET proteins. In addition, structural model of DRM suggested that circular permutation of motifs does not have any effect on overall structure of DNA methyltransferase domain. These results provide valuable insights into role of various domains in molecular recognition and should facilitate mechanistic understanding of their function in mediating specific methylation patterns. Further, the comprehensive gene expression analyses of MTases in legumes provided evidence of their role in various developmental processes throughout the plant life cycle and response to various abiotic stresses. Overall, our study will be very helpful in establishing the specific functions of DNA MTases in legumes.

The influences of structural and aerodynamic modeling on the flutter analysis and multidisciplinary optimization of fully built-up finite element wing models in an aeroelastic environment are not yet well understood. Therefore, the dynamic aeroelastic and optimization capabilities in the Automated Structural Optimization System (ASTROS) were used to evaluate the flutter behavior and the behavior of structural optimization with flutter constraints of various representative fully built-up finite element wing models in subsonic and supersonic flow. ASTROS was here used as a tool to calculate flutter speeds and frequencies and to minimize the weight of these wing models in subsonic and supersonic flow under given flutter and frequency constraints to determine the effect that these modeling factors have. Structures, ASTROS, Aeroelasticity, Modelling, Optimization.

This thesis examine opportunities for the application of information technology through mathematical modeling and design of a new method of a ship's space monitoring for the support of command decisions during a fire aboard. Thesis analyzes peculiarities of a fire and difficulties inherent in gathering data, particularly the lack of objective information about a fire scale, fire dynamics, and timing of functioning the ship's equipment during an emergency aboard. It was shown that, in a closed compartment, a gas pressure monitoring is a very perspective way of determining a fire scale and its propagation ability. The appropriate models of fire development were created. They were designed in a way of using only those data that were possible to observe during a fire aboard. Depending on availability and quality of current information about the fire, an informative tree of alternative scenarios of the fire hazard analysis and command decisions was developed. Conducted in terms of decision theory concept, formalization of fire-fighting procedure permitted to accomplish structural and cost benefit analysis of the command decisions during a fire aboard. Relevant chronological decision tree diagrams were designed. Structural analysis proved that application of information technology and new method of gas pressure monitoring significantly increases efficiency of command decisions during a fire without considerable additional costs.

The development of a wavelet-based feature extraction technique specifically targeting FOD-event induced vibration signal changes in gas turbine engines is described. The technique performs wavelet analysis of accelerometer signals from specified locations on the engine and is shown to be robust in the presence of significant process and sensor noise. It is envisioned that the technique will be combined with Kalman filter thermal/health parameter estimation for FOD-event detection via information fusion from these (and perhaps other) sources. Due to the lack of high-frequency FOD-event test data in the open literature, a reduced-order turbofan structural model (ROM) was synthesized from a finite element model modal analysis to support the investigation. In addition to providing test data for algorithm development, the ROM is used to determine the optimal sensor location for FOD-event detection. In the presence of significant noise, precise location of the FOD event in time was obtained using the developed wavelet-based feature.

The development of an accurate model of uncertainties for the control of structures that undergo a change in operational environment, based solely on modeling and experimentation in the original environment is studied. The application used throughout this work is the development of an on-orbit uncertainty model based on ground modeling and experimentation. A ground based uncertainty model consisting of mean errors and bounds on critical structural parameters is developed. The uncertainty model is created using multiple data sets to observe all relevant uncertainties in the system. The Discrete Extended Kalman Filter is used as an identification/parameter estimation method for each data set, in addition to providing a covariance matrix which aids in the development of the uncertainty model. Once ground based modal uncertainties have been developed, they are localized to specific degrees of freedom in the form of mass and stiffness uncertainties. Two techniques are presented: a matrix method which develops the mass and stiffness uncertainties in a mathematical manner; and a sensitivity method which assumes a form for the mass and stiffness uncertainties in macroelements and scaling factors. This form allows the derivation of mass and stiffness uncertainties in a more physical manner. The mass and stiffness uncertainties of the ground based system are then mapped onto the on-orbit system, and projected to create an analogous on-orbit uncertainty model in the form of mean errors and bounds on critical parameters. The Middeck Active Control Experiment is introduced as experimental verification for the localization and projection methods developed. In addition, closed loop results from on-orbit operations of the experiment verify the use of the uncertainty model for control analysis and synthesis in space.

This paper, in a fashion easy to follow, illustrates the interesting relationship between structural equation modeling and canonical correlation analysis. Although computationally somewhat inconvenient, representing canonical correlation as a structural equation model may provide some information which is not available from conventional canonical correlation analysis. Hierarchically, with regard to the degree of generality of the techniques, it is suggested that structural equation modeling stands to be a more general approach. For researchers interested in these techniques, understanding the interrelationship among them is meaningful, since our judicious choice of these analytic techniques for our research depends on such understanding. Three tables and two figures present the data. (Contains 25 references.) (Author)

The development of an accurate model of uncertainties for the control of structures that undergo a change in operational environment, based solely on modeling and experimentation in the original environment is studied. The application used throughout this work is the development of an on-orbit uncertainty model based on ground modeling and experimentation. A ground based uncertainty model consisting of mean errors and bounds on critical structural parameters is developed. The uncertainty model is created using multiple data sets to observe all relevant uncertainties in the system. The Discrete Extended Kalman Filter is used as an identification/parameter estimation method for each data set, in addition to providing a covariance matrix which aids in the development of the uncertainty model. Once ground based modal uncertainties have been developed, they are localized to specific degrees of freedom in the form of mass and stiffness uncertainties. Two techniques are presented: a matrix method which develops the mass and stiffness uncertainties in a mathematical manner; and a sensitivity method which assumes a form for the mass and stiffness uncertainties in macroelements and scaling factors. This form allows the derivation of mass and stiffness uncertainties in a more physical manner. The mass and stiffness uncertainties of the ground based system are then mapped onto the on-orbit system, and projected to create an analogous on-orbit uncertainty model in the form of mean errors and bounds on critical parameters. The Middeck Active Control Experiment is introduced as experimental verification for the localization and projection methods developed. In addition, closed loop results from on-orbit operations of the experiment verify the use of the uncertainty model for control analysis and synthesis in space.

Computerized engineering architectures promise to significantly improve the process for designing complex systems. This paper investigates the application of the Adaptive Modeling Language to the aircraft design process. Models were developed to perform a limited activity-based cost vs. structural performance trade study on wing box. These disciplines were chosen because cost is becoming increasingly important in today's defense environment and it is not handled as systematically as the physics-based analyses by conventional aircraft design processes. Besides demonstrating the feasibility of combining diverse disciplines in a single engineering environment, this paper documents the time savings that can be realized by automating some repetitive design tasks.

The final stage of the proposed research was completed during this performance period. The focus of this work was on integrating the composite damage analysis programs into a framework where they could be effectively used for design optimization. Critical to this phase of the work was a problem formulation that took into consideration the multiscale nature of the damage process, and fully accounted for the residual life in the composite structure in a post-failure (local failure mode). A system effectiveness approach was developed as a logical framework for the design problem formulation. This approach fully accounts for the probabilities of going from one state of structural damage to another. The problem formulation also allows for creating objective criteria that include system reliability and residual life in the structure. The approach was demonstrated using simple composite design problems.

Resilience is a new approach for assessing and enhancing the resilience of cities’ development foundations. The purpose of this research is to model the key drivers effective in increasing the physical resilience of the district 10 of Tehran against earthquakes with a futuristic approach and designing the relationships between the key drivers. This study was conducted using descriptiveanalytical method, and the key drivers affecting the increase of physical resilience were identified using content analysis method. In the modeling section, through Delphi method, the opinions of academic experts of physical resilience were obtained. Interview and a questionnaire were used to collect data. The validity of the questionnaire was evaluated using face validity criteria. Relationships between the key drivers affecting the increase of physical resilience of the studied sample against earthquakes were determined and analyzed by the interpretive structural modeling (ISM) method. Finally, using Micmac analysis, the key effective drivers were identified and classified in six levels according to their impact on other factors. The results show that the driver “granulation class” has the highest penetration force and is infrastructure and the main stimulus of urban physical resilience. Any action to increase the physical resilience of the sample against earthquakes requires modifications in this driver. Service distribution and the strength of public buildings have the least impact with 1 and 3 penetration force, respectively. The results also show that elements at higher levels have less stimulating power and more dependence.

A process for aerospace structural concept analysis and design is presented, with examples of a blended-wing-body fuselage, a multi-bubble fuselage concept, a notional crew exploration vehicle, and a high altitude long endurance aircraft. Aerospace vehicle structures must withstand all anticipated mission loads, yet must be designed to have optimal structural weight with the required safety margins. For a viable systems study of advanced concepts, these conflicting requirements must be imposed and analyzed early in the conceptual design cycle, preferably with a high degree of fidelity. In this design process, integrated multidisciplinary analysis tools are used in a collaborative engineering environment. First, parametric solid and surface models including the internal structural layout are developed for detailed finite element analyses. Multiple design scenarios are generated for analyzing several structural configurations and material alternatives. The structural stress, deflection, strain, and margins of safety distributions are visualized and the design is improved. Over several design cycles, the refined vehicle parts and assembly models are generated. The accumulated design data is used for the structural mass comparison and concept ranking. The present application focus on the blended-wing-body vehicle structure and advanced composite material are also discussed.

A process for aerospace structural concept analysis and design is presented, with examples of a blended-wing-body fuselage, a multi-bubble fuselage concept, a notional crew exploration vehicle, and a high altitude long endurance aircraft. Aerospace vehicle structures must withstand all anticipated mission loads, yet must be designed to have optimal structural weight with the required safety margins. For a viable systems study of advanced concepts, these conflicting requirements must be imposed and analyzed early in the conceptual design cycle, preferably with a high degree of fidelity. In this design process, integrated multidisciplinary analysis tools are used in a collaborative engineering environment. First, parametric solid and surface models including the internal structural layout are developed for detailed finite element analyses. Multiple design scenarios are generated for analyzing several structural configurations and material alternatives. The structural stress, deflection, strain, and margins of safety distributions are visualized and the design is improved. Over several design cycles, the refined vehicle parts and assembly models are generated. The accumulated design data is used for the structural mass comparison and concept ranking. The present application focus on the blended-wing-body vehicle structure and advanced composite material are also discussed.

A process for aerospace structural concept analysis and design is presented, with examples of a blended-wing-body fuselage, a multi-bubble fuselage concept, a notional crew exploration vehicle, and a high altitude long endurance aircraft. Aerospace vehicle structures must withstand all anticipated mission loads, yet must be designed to have optimal structural weight with the required safety margins. For a viable systems study of advanced concepts, these conflicting requirements must be imposed and analyzed early in the conceptual design cycle, preferably with a high degree of fidelity. In this design process, integrated multidisciplinary analysis tools are used in a collaborative engineering environment. First, parametric solid and surface models including the internal structural layout are developed for detailed finite element analyses. Multiple design scenarios are generated for analyzing several structural configurations and material alternatives. The structural stress, deflection, strain, and margins of safety distributions are visualized and the design is improved. Over several design cycles, the refined vehicle parts and assembly models are generated. The accumulated design data is used for the structural mass comparison and concept ranking. The present application focus on the blended-wing-body vehicle structure and advanced composite material are also discussed.

This article is from BMC Research Notes , volume 7 . Abstract Background: SG2NA is a member of the striatin sub-family of WD-40 repeat proteins. Striatin family members have been associated with diverse physiological functions. SG2NA has also been shown to have roles in cell cycle progression, signal transduction etc. They have been known to interact with a number of proteins including Caveolin and Calmodulin and also propagate the formation of a multimeric protein unit called striatin-interacting phosphatase and kinase. As a pre-requisite for such interaction ability, these proteins are known to be unstable and primarily disordered in their arrangement. Earlier we had identified that it has multiple isoforms (namely 35, 78, 87 kDa based on its molecular weight) which are generated by alternative splicing. However, detailed structural information of SG2NA is still eluding the researchers. Results: This study was aimed towards three-dimensional molecular modeling and characterization of SG2NA protein and its isoforms. One structure out of five was selected for each variant having the least value for C score. Out of these, m35 kDa with a C score value of −3.21was the most poorly determined structure in comparison to m78 kDa and m87 kDa variants with C scores of −1.16 and −1.97 respectively. Further evaluation resulted in about 61.6% residues of m35 kDa, 76.6% residues of m78 kDa and 72.1% residues of m87 kDa falling in the favorable regions of Ramchandran Plot. Molecular dynamics simulations were also carried out to obtain biologically relevant structural models and compared with previous atomic coordinates. N-terminal region of all variants was found to be highly disordered. Conclusion: This study provides first-hand detailed information to understand the structural conformation of SG2NA protein variants (m35 kDa, m78 kDa and m87 kDa). The WD-40 repeat domain was found to constitute antiparallel strands of β-sheets arranged circularly. This study elucidates the crucial structural features of SG2NA proteins which are involved in various protein-protein interactions and also reveals the extent of disorder present in the SG2NA structure crucial for excessive interaction and multimeric protein complexes. The study also potentiates the role of computational approaches for preliminary examination of unknown proteins in the absence of experimental information.

This article is from BMC Research Notes , volume 7 . Abstract Background: SG2NA is a member of the striatin sub-family of WD-40 repeat proteins. Striatin family members have been associated with diverse physiological functions. SG2NA has also been shown to have roles in cell cycle progression, signal transduction etc. They have been known to interact with a number of proteins including Caveolin and Calmodulin and also propagate the formation of a multimeric protein unit called striatin-interacting phosphatase and kinase. As a pre-requisite for such interaction ability, these proteins are known to be unstable and primarily disordered in their arrangement. Earlier we had identified that it has multiple isoforms (namely 35, 78, 87 kDa based on its molecular weight) which are generated by alternative splicing. However, detailed structural information of SG2NA is still eluding the researchers. Results: This study was aimed towards three-dimensional molecular modeling and characterization of SG2NA protein and its isoforms. One structure out of five was selected for each variant having the least value for C score. Out of these, m35 kDa with a C score value of −3.21was the most poorly determined structure in comparison to m78 kDa and m87 kDa variants with C scores of −1.16 and −1.97 respectively. Further evaluation resulted in about 61.6% residues of m35 kDa, 76.6% residues of m78 kDa and 72.1% residues of m87 kDa falling in the favorable regions of Ramchandran Plot. Molecular dynamics simulations were also carried out to obtain biologically relevant structural models and compared with previous atomic coordinates. N-terminal region of all variants was found to be highly disordered. Conclusion: This study provides first-hand detailed information to understand the structural conformation of SG2NA protein variants (m35 kDa, m78 kDa and m87 kDa). The WD-40 repeat domain was found to constitute antiparallel strands of β-sheets arranged circularly. This study elucidates the crucial structural features of SG2NA proteins which are involved in various protein-protein interactions and also reveals the extent of disorder present in the SG2NA structure crucial for excessive interaction and multimeric protein complexes. The study also potentiates the role of computational approaches for preliminary examination of unknown proteins in the absence of experimental information.

Gasdynamic analysis for the turbine blades and nozzle vanes, HPFTP turbine analysis, and HPOTP turbine analysis are provided.

"June 1999"