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The purpose of this paper is to identify the flexible aircraft model accurately from the frequency responses.

The frequency domain output error method is used to estimate the aerodynamic (rigid body and elastic body) derivatives, and mode shape parameters in the process of identification of flexible aircraft model. The accurate identification of lightly damped low frequency rigid-body response modes requires a careful selection of the frequency sweep length and the fast Fourier transform (FFT) window size, as the FFT window length cannot be longer than any individual sweep records. To address this issue, an effort is made to derive the FFT window length for the application of frequency domain estimation approach.

The investigations are initially made to select a suitable FFT window size for the accurate identification of the lightly damped low frequency rigid-body response modes of the flexible aircraft. Subsequently, frequency domain estimation approach is applied to simulated data of flexible aircraft. Besides the stability and control derivatives, the structural modes of the flexible aircraft are also estimated as part of state space model identification, and it is shown that all the model parameter estimates are accurate. Identification of such flexible aircraft aerodynamic (rigid body and elastic body) derivatives and structural mode shape parameters will lead to mathematical models of flexible aircraft that are accurate over a wide frequency range. The identified models are validated using the time response of frequency sweep data.

Aircraft system identification is an integral part of aerospace system design and life cycle process. This becomes a complex process when the aircraft has significant effects of flexibility on the flight dynamics, especially as the frequencies of the elastic modes become lower and approach those of the rigid body modes. Thus, an integrated mathematical model of flexible aircraft is required to develop, and it should be valid for a wide frequency range and relevant for the design of flight control system.

This paper focuses on the application of frequency domain approach to identify the valid model of flexible aircraft by estimating the aerodynamic (rigid body and elastic body) derivatives and structural mode shape parameters of flexible aircraft. The unknown frequencies of structural modes are also able to identify accurately in frequency domain. This gives more value addition to analyze the flight data of flexible aircraft, as it is challenging problem in parameter estimation of flexible aircraft.

The purpose of this paper is to identify how intervention research weighed in nonintervention research in the field of human resource development (HRD) by examining the number, citation frequency and use of experimental studies in HRD academic journals.

A total of 2,700 articles published between 1990 and 2014 from Advances in Developing Human Resources (ADHR), European Journal of Training and Development (EJTD), Human Resource Development International (HRDI) and Human Resource Development Quarterly (HRDQ) were reviewed and analyzed to identify 91 experimental studies in the field.

The total citation frequency of the 91 articles was 1,100 (14 from ADHR, 222 from EJTD, 56 from HRDI and 808 from HRDQ). The authors reviewed the 1,100 subsequent studies that cited 91 experimental research studies and coded them to identify the research methods that each article adopted and to determine whether the studies used the citation to make causal statements. As a result, the authors found 459 causal statements from 1,100 citations. In particular, they identified the citation frequency of the causal statements used in nonintervention research to examine how often nonintervention studies used causal statements from intervention studies.

The results of the citation frequency could be different according to the search engines and timeframes. Books, technical reports, non-English studies, non-academic articles and inaccessible articles were not considered in this study. Theoretically, this study aimed to illuminate the magnitude of HRD experimental research conducted over 25 years and to what extent it influenced non-experimental studies. In addition, this study emphasized the importance of using the causal statements from experimental research to improve empirical validation in other studies.

When HRD practitioners need to identify alternative interventions to replace previous ones or to justify the use of specific interventions, they could consider causal statements from empirical studies as valid evidence. Further, HRD practitioners might collaborate with researchers to receive more direct and relevant information from experimental research.

Significantly, this study provides an integrative review of experimental research conducted in the field of HRD in terms of the number, citation frequency and proportion of using experimental research. An additional contribution is that it summarizes the research methods used in HRD studies over 25 years.

Few of the established risk identification methods refer to low-severity yet high-frequency safety risks data that may lead to several safety risks being ignored, thus reducing the potential of learning from a considerable number of cases. The purpose of this study is to explore a new valid method based on preaccident safety supervision data to identify these minor construction safety risks during routine construction operations.

A total of 329 official construction safety supervision reports containing 5,159 safety problem records from Shanghai between 2016 and 2018 served as raw material for in-depth analysis. Given the characteristics of the data collected, text mining integrated with natural language processing was applied to review the supervision reports and group safety risks automatically.

This study clarifies the way in which the supervision data should be employed to analyze high-frequency–low-severity safety risks. From these data, seven unsafe-act-related and nine unsafe-condition-related risks are identified. Regarding unsafe-act-related risks, inappropriate human behaviors could usually occur in personnel management, contract management, expense management, material management and acceptance work. For unsafe-condition-related risks, hoisting, scaffolding and reinforcement works are the main generators of onsite safety hazards during construction operations.

The study includes implications for project managers and supervisors to facilitate more effective proactive risk management by paying more attention to collecting and employing the supervision data established in each routine inspection.

Whereas previous research focused on analyzing severe accidents, this study seeks to identify the high-frequency–low-severity construction safety risks using the preaccident supervision data. The findings could provide a new thought and research direction for construction safety risk management.

When a manipulator captures an unknown space object, inertia parameters of endpoint payload should be timely obtained to handle possible unexpected parameter variations and monitor the system’s operating conditions. Therefore, this study aims to present an identification method for estimating the inertia parameter of the payload carried by a flexible two-link space manipulator.

The original nonlinear dynamics model of the manipulator is linearized at a selected working point. Subsequently, the system modal frequencies with and without payload are determined using the subspace identification algorithm, and the difference of these frequencies is computed. Furthermore, by adjusting the structural configuration of the manipulator, multiple sets of frequency differences are obtained. Therefore, the inertia parameters of the payload, i.e. the mass and the moment of inertia, can be derived from the frequency differences by solving a least-squares problem.

The proposed method can effectively estimate the payload parameters and has satisfactory identification accuracy.

The approach’s implementation provides a practical reference for determining inertia parameters of an unknown space target in the capture process.

The study proposes a novel method for identifying the inertia parameters of the payload of a flexible two-link space manipulator using the estimated system frequencies.

The paper seeks to describe the state‐of‐the‐art, reasons for selecting various material planning methods, and modes of applying methods for initiating inventory replenishment of purchased items. It also identifies trends from 1993 to 2005.

Empirical survey data are collected from Swedish manufacturing companies in 1993, 1999 and 2005. The MRP, re‐order point, fixed interval ordering, run‐out time, and Kanban methods are studied.

MRP is the most commonly used method and its position has strengthened since 1993. A common way of determining parameters such as order quantities and safety stocks is to use judgment and experience. Parameters used in material planning methods are reviewed relatively infrequently. The planning frequency has increased, with daily planning now being typical.

The major limitation is that different data collection techniques were used in 1993 compared with 1999 and 2005. An important research implication is that the state‐of‐the‐art applications differ from theoretically appropriate application modes. The trends are towards less appropriate modes among the most widespread applications.

The frequency of reviewing planning variables is relatively low in industry, and should in most situations be increased. The paper implies that more user‐friendly software applications need to be developed and implemented. It could serve as guidelines when designing and developing training and education programs and function as a benchmark.

The paper provides a longitudinal state‐of‐the‐art description of materials planning usage and identifies application modes with positive and negative performance impact.

Owing to the cable flexibility, it is practically a lot easier to measure the high‐vibration frequencies of the cable than the fundamental vibration frequency. The objective of this study is to present a method to determine the cable tension based on frequency differences so that the effects of cable sag and bending stiffness can be included.

The paper includes theoretical derivation, laboratory study to verify the method and practical application in a real bridge.

It is suggested to measure the high‐vibration frequencies, and to use the vibration frequency difference to determine the fundamental vibration frequency of the cable and then to estimate the cable tension. The reliability of the method is verified by laboratory tests and the method is then applied to determine cable tensions in a real bridge.

This paper provides theoretical derivations to demonstrate that under certain conditions, the frequency difference of a cable with sag and bending is almost equal to the natural frequency of the same cable when it is taut. This unique characteristic of cable vibration is used to determine the cable tension similar to the fundamental frequency‐based taut‐string formula that is commonly used in practice.

The purpose of this paper is to identify the profiles of those frequenting full-service restaurants and eating raw vegetable salads, as well as to analyze the influence of socio-demographic variables and of the tendency for social desirability in consumption frequencies.

A non-probabilistic consumer sample (n=630) was interviewed in the city of Campinas, Brazil. Besides the frequency of eating in full-service restaurants and the frequency of eating salads (as a function of the meal type and week day) in this type of restaurant, the survey instrument was also composed by socio-demographic variables and a social desirability scale. To compare data, non-parametric tests were used.

Of the interviewees, 52.3 percent were shown to eat in full-service restaurants at least once a week. The frequency of eating salads in full-service restaurant stood out as being significantly higher (p<0.05) for weekday lunches. Individuals who graduated in the areas of health or food showed a significantly higher frequency for the consumption of salads at weekends. Apparently the social desirability did not influence the responses of the consumers with respect to the frequencies studied.

The sample was of a non-probabilistic type, bringing reservations with respect to generalizations.

Socio-demographic variables should be considered in elaborating strategies for promoting vegetable salads consumption in restaurants. Health and nutrition education programs can be effective in aiding consumers to choose healthier food in this context.

Studies about frequency of salad consumption in restaurants are scarce. The influence of social desirability bias on reported frequency was analyzed in this paper.

Condition monitoring (CM) of structures is important from safety consideration. Damage detection techniques, using inverse dynamic approaches, are important tools to improve the mathematical models for monitoring the condition of structure. Uncertainties in the measured data might lead to unreliable identification of damage in structural system. Experimental validation is crucial for establishing its practical applicability. The measurement of dynamic responses at all degrees of freedom (DOFs) of a structure is also not feasible in practice. In addition the effect of these uncertainties and constraint of limited measurement are required to be studied based on experimental validation. This paper aims to discuss these issues.

Proposed numerical model based on measured natural frequencies and mode shapes is found suitable for CM of framed structures in the framework of finite element model with limited dynamic responses. The structural properties, namely, axial rigidity and bending rigidity are identified at the element level in the updated models of the system. Damage at the element level is identified by comparing the identified structural parameters of the updated model of the system with those of the undamaged state. Proposed numerical model is suitable for practical problem, as it is able to identify the structural parameters with limited modal data of first few modes, measured at selected DOFs.

The model is able to identify the structural damage with greater accuracy from the noisy dynamic responses even if the extent of damage is small. Experimental studies, on simple cantilever beams, establish the potential of the proposed methods for its practical implementation.

The greater random noise will lead to unreliable identification of structural parameters as observed. Thus, filtering of noise technique may be required to be adopted prior to consideration of the measured data in the proposed identification approach.

Requirement of higher modal data seems to be difficult in case of real life practical problem. Thus, simulation technique like condensation or SEREP technique may be adopted.

Structural health monitoring of infrastructural system is significantly important. CM of those structures from global response with limited measured data seems to be an effective tool to ensure safety and durability of structures.

The modal testing and subsequent extraction of modal data have been carried out at the authors’ laboratory. The numerical code based on inverse dynamic approach has been developed independently with original contribution.

The concept of green supply chain management (GSCM) is evolving rapidly due to the environmental concerns and gaining popularity in the research community. This study critically analyze the literature of GSCM pressure, practice and performance for manufacturing enterprises based on the results of bibliometric, network and frequency analyses.

Scopus database is used for literature search. Bibliometric network and frequency analysis are used to critically review the evolution of identified constructs and measures of GSCM pressure, practice and performance.

This study has identified that the selected topic is in growing stage through the collaborative effort of the worldwide researchers. This study also shows the diffusion of influence in developing countries and there are enormous opportunities of research in these regions. The study finds evaluation of GSCM constructs and measures with time and shift in focus areas by the researchers. The study suggests more focus on the measurement of informative pressures, reverse logistics practices and negative impact on economic performance due to the adoption of GSCM practices. There is a need of simultaneous analysis of GSCM pressures, practices and performance to identify the cascading effect in different regions and industrial sectors and developed a conceptual framework to identify this effect. This study also observes the need of more quantitative measures-based case studies and suggests the use of life cycle assessment for the quantification of environmental performance.

This study for the first time has analyzed a specific topic of GSCM pressure, practice and performance through bibliometric and network analyses. This study critically reviews the constructs and measures of GSCM pressure, practice and performance and identified the future research directions.

This study aims to perform the experimental work on a laboratory-constructed steel truss bridge model on which hammer blows are applied for excitation. The vibration response signals of the bridge structure are collected using sensors placed at different nodes. The different damaged states such as no damage, single damage, double damage and triple damage are introduced by cutting members of the bridge. The masked noise with recorded vibration responses generates challenge to properly analyze the health of bridge structure.

The analytical modal properties are obtained from finite element model (FEM) developed using SAP2000 software. The response signals are analyzed in frequency domain by power spectrum and in time-frequency domain using spectrogram and Stockwell transform. Various low pass signal-filtering techniques such as variational filter, lowpass sparse banded (AB) filter and Savitzky–Golay (SG) differentiator filter are also applied to refine vibration signals. The proposed methodology further comprises application of Hilbert transform in combination with MUSIC and ESPRIT techniques.

The outcomes of SG filter provided the denoised signals using appropriate polynomial degree with proper selected window length. However, certain unwanted frequency peaks still appeared in the outcomes of SG filter. The SG-filtered signals are further analyzed using fused methodology of Hilbert transform-ESPRIT, which shows high accuracy in identifying modal frequencies at different states of the steel truss bridge.

The sequence of proposed methodology for denoising vibration response signals using SG filter with Hilbert transform-ESPRIT is a novel approach. The outcomes of proposed methodology are much refined and take less computational time.