Simulating Building Motions Using Ratios of the Building's Natural Frequencies and a Timoshenko Beam Model

A simple prismatic Timoshenko beam model with soil-structure interaction (SSI) is developed to approximate the dynamic linear elastic behavior of buildings. A closed-form solution with complete vibration modes is derived. It is demonstrated that building properties, including mode shapes, can be derived from knowledge of the natural frequencies of the first two translational modes in a particular direction and from the building dimensions. In many cases, the natural frequencies of a building's first two vibrational modes can be determined from data recorded by a single seismometer. The total building's vibration response can then be simulated by the appropriate modal summation. Preliminary analysis is performed on the Caltech Millikan Library, which has significant bending deformation because it is much stiffer in shear

The practice of measurements for shared value initiatives by public sector organizations in Malaysia

This paper highlights the paradox that many public sector organisations face in simultaneously pursuing specific organisation goals and creating shared values for societies. While there are performance indicators to measure efficiency in the attainment of organisation goals in the public sector, there is little research on measures of performance in creating actual shared value for the target communities from the communities’ perspective. An investigative study of a shared value initiative for a business community in a strategic development zone by a publiclyowned corporation in Malaysia is discussed. The findings support the relevance and necessity of a performance prediction process in public sector organisations to encourage managerial accountability and achieve valued outcomes for target communities. The findings contribute to the academic literature on measures of effectiveness for shared value initiatives by public sector organisations that may lead to improvements in practice within these organisations

Interpretation of Millikan Library's Vibrating Modes Using A Magneto Coil To Measure Phase Shifts

A new set of natural frequencies for the 9-story reinforced concrete Millikan Library building on the Caltech campus is computed using the observed phase shift between the driving force of a shaker installed on the building’s roof and structural response at resonance. The phase of the shaker’s output force was recorded by a magneto coil and magnet attached to the shaker’s rotating mechanism, and the phase of the structural response was obtained from acceleration time series recorded by an accelerometer on the roof. These new results refute previous studies’ identification of the 3rd EW and 2nd torsional modes which used spectral analysis of forced and free vibrations, but did not consider the phase shift. In addition, the newly identified 3rd EW mode shape is independent of the other EW mode shapes, unlike previous findings. This new interpretation is compatible with results from subspace system identification based on two sets of earthquake records

The Community Seismic Network and Quake-Catcher Network: enabling structural health monitoring through instrumentation by community participants

A new type of seismic network is in development that takes advantage of community volunteers to install low-cost accelerometers in houses and buildings. The Community Seismic Network and Quake-Catcher Network are examples of this, in which observational-based structural monitoring is carried out using records from one to tens of stations in a single building. We have deployed about one hundred accelerometers in a number of buildings ranging between five and 23 stories in the Los Angeles region. In addition to a USB-connected device which connects to the host’s computer, we have developed a stand-alone sensor-plug-computer device that directly connects to the internet via Ethernet or wifi. In the case of the Community Seismic Network, the sensors report both continuous data and anomalies in local acceleration to a cloud computing service consisting of data centers geographically distributed across the continent. Visualization models of the instrumented buildings’ dynamic linear response have been constructed using Google SketchUp and an associated plug-in to matlab with recorded shaking data. When data are available from only one to a very limited number of accelerometers in high rises, the buildings are represented as simple shear beam or prismatic Timoshenko beam models with soil-structure interaction. Small-magnitude earthquake records are used to identify the first set of horizontal vibrational frequencies. These frequencies are then used to compute the response on every floor of the building, constrained by the observed data. These tools are resulting in networking standards that will enable data sharing among entire communities, facility managers, and emergency response groups

Accessory spleen as lead point in intussusception

A 15-year-old boy, who had an episode of abdominal colic 4 years earlier, presented now with a week-long episode of abdominal pain. A computed tomographic scan confirmed the presence of an intussusception. Surprisingly, the surgery identified an accessory spleen as the lead point. At 9 months follow-up, the young boy has had no further abdominal discomfort. This report adds accessory spleen to the list of very rare pathological lead points in intussusception

Prediction of Wave Propagation in Buildings Using Data from a Single Seismometer

Crowd‐sourced seismic networks in buildings collect important scientific data, in addition to allowing a diverse audience to visualize the vibrations of buildings. Visualization of a building’s deformation requires spatiotemporal interpolation of motions from seismometers that are located wherever the crowd places them. In many cases, a crowd‐sourced building network may actually be just a single seismometer. A method to rapidly estimate the total displacement response of a building based on limited observational data, in some cases from only a single seismometer, is presented. In general, the earliest part of the response is simulated by assuming a vertically propagating shear wave. Later motions are simulated using mode shapes derived from a beam model (a shear beam, or more generally a Timoshenko beam), the parameters of which are determined from the ratios of the modal frequencies and the building’s exterior dimensions. The method is verified by (1) comparing predicted and actual records from a 54‐story building in downtown Los Angeles, California, and (2) comparing finite‐element simulations of the 17‐story University of California, Los Angeles (UCLA) Factor building. The response of each of these buildings can be simulated with a simple shear beam. The importance of including the traveling wave part of the solution depends on the characteristics of the base ground shaking; the traveling wave becomes more apparent as the excitation becomes more impulsive. The method can be straightforwardly applied to multiple instrumented buildings, resulting in a tool to visualize linear elastic motions of those buildings

Lipoxin A4 preconditioning attenuates intestinal ischemia reperfusion injury through Keap1/Nrf2 pathway in a lipoxin A4 receptor independent manner

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A validation study of a smartphone application for functional mobility assessment of the elderly

Background: To minimize the reaction time and position judgment error using stopwatch-timed measures, we developed a smartphone application to measure performance in the five-time sit-to-stand (FTSTS) and timed up-and-go (TUG) tests. Objective: This study aimed to validate this smartphone application by comparing its measurement with a laboratory-based reference condition. Methods: Thirty-two healthy elderly people were asked to perform the FTSTS and TUG tests in a randomized sequence. During the tests, their performance was concurrently measured by the smartphone application and a force sensor installed in the backrest of a chair. The intraclass correlation coefficient [ICC(2,1)] and Blande-Altman analysis were used to calculate the measurement consistency and agreement, respectively, between these two methods. Results: The smartphone application demonstrated excellent measurement consistency with the lab-based reference condition for the FTSTS test [ICC(2,1) = 0.988] and TUG test [ICC(2,1) = 0.946]. We observed a positive bias of 0.27 seconds (95% limits of agreement, -1.22 to 1.76 seconds) for the FTSTS test and 0.48 seconds (95% limits of agreement, -1.66 to 2.63 seconds) for the TUG test. Conclusion: We cross-validated the newly developed smartphone application with the laboratory-based reference condition during the examination of FTSTS and TUG test performance in healthy elderly