• Wind and Structures
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• v.21 no.1
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• pp.1-23
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• 2015

Wind tunnel testing of a low-rise building with openings (holes) of different sizes and shapes on a roof corner is conducted to measure the internal and external pressures from the building model. Detailed analysis of the testing data is carried out to investigate the characteristics of the internal and external pressures of the building with different openings' configurations. Superimposition of the internal and external pressures makes the emergence of positive net pressures on the roof. The internal pressures demonstrate an overall uniform distribution. The probability density function (PDF) of the internal pressures is close to the Gaussian distribution. Compared with the PDF of the external pressures, the non-Gaussian characteristics of the net pressures weakened. The internal pressures exhibit strong correlation in frequency domain. There appear two humps in the spectra of the internal pressures, which correspond to the Helmholtz frequency and vortex shedding frequency, respectively. But, the peak for the vortex shedding frequency is offset for the net pressures. Furthermore, the internal pressure characteristics indirectly reflect that the length of the front edge enhances the development of the conical vortices.The objective of this study aims to further understanding of the characteristics of internal, external and net pressures for low-rise buildings in an effort to reduce wind damages to residential buildings.

• The korean journal of orthodontics
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• v.13 no.1
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• pp.15-30
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• 1983

This study was to investigate the effect of functional pressures of the tongue and lips on the incisor relationship. The incisor relationship was devided into two categories; one is vertical relationship which is subdevided into open bite, normal overbite and deep bite on the basis of overbite, and the other is anteroposterior relationship which is subdevided into cross bite, normal overjet and large overjet on the basis of overjet. The functional tongue and lip pressures exerted to incisors were measured with subminiature pressure sense from the 99 subjects, 19 of normal overbite and overjet, 26 of open bite, 18 of deep bite, 17 of cross bite and 19 of large overjet with age of 17-20, and cephalograms were taken from the same subjects. Functional pressures were analyzed and correlated to craniofacial veriables. The results of present investigation led to the following conclusions. 1. There were no differences in functional and maximum pressures by the tongue and lips exerted to maxillary incisors between normal occlusion, open bite, deep bite, cross bite and large overjet. 2. Significant differences in functional and maximum pressures by the tongue and lips exerted to mandibular incisors have been shown to exist between open bite and deep bite, but no differences between cross bite and large overjet. 3. Equilibrium between tongue pressures and lip pressures did not exist. 4. Significant differences in the ratio of upper functional and maximum pressures to lower pressures of the tongue and lips exerted to upper and lower incisors have been shown to exist between open bite and deep bite, and no differences between cross bite and large overjet. 5, There was significant correlation between functional and maximum pressures exerted to mandibular incisors and craniofacial variables, but not significant correlation between functional and maximum pressures exerted to maxillary incisors and craniofacial variables.

• Wind and Structures
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• v.30 no.3
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• pp.219-229
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• 2020

Net pressures on roofs and walls of buildings are dependent on the internal and external pressure fluctuations. The variation of internal and external pressures are influenced by the size and location of the openings. The correlation of external and internal pressure influences the net pressures acting on cladding on different parts of the roof and walls. The peak internal and peak external pressures do not occur simultaneously, therefore, a reduction can be applied to the peak internal and external pressures to obtain a peak net pressure for cladding design. A 1:200 scale wind tunnel model study was conducted to determine the correlations of external and internal pressures and effective reduction to net pressures (i.e., net pressure factors, F_C) for roof and wall cladding. The results show that external and internal pressures on the windward roof and wall edges are well correlated. The largest ${\mathcal{C}}_{{\check{p},net}$, highest correlation coefficient and the highest F_C are obtained for different wind directions within 90° ≤ θ ≤ 135°, where the large openings are on the windward wall. The study also gives net pressure factors F_C for areas on the roof and wall cladding for nominally sealed buildings and the buildings with a large windward wall opening. These factors indicate that a 5% to 10% reduction to the action combination factor, K_C specified in AS/NZS 1170.2(2011) is possible for some critical design scenarios.

• The Journal of the Acoustical Society of Korea
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• v.22 no.1E
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• pp.11-18
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• 2003

Non-singular boundary element method (BEM) codes are developed in acoustics application. The BEM code is then used to calculate unknown boundary surface normal displacements and surface pressures from known exterior near field pressures. And then the calculated surface normal displacements and surface pressures are again applied to the BEM in forward in order to calculate reconstructed field pressures. The initial exterior near field pressures are very well agreed with the later reconstructed field pressures. Only the same number of boundary surface nodes (1178) are used for the initial exterior pressures which are at first calculated by Finite Element Method (FEM) and BEM. Pseudo-inverse technique is, used for the calculation of the unknown boundary surface normal displacements. The structural object is a tuning fork with 128.4 ㎐ resonant. The boundary element is a quadratic hexahedral element (eight nodes per element).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.306-311
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• 2002

Non-singular boundary element method (BEM) codes are developed in acoustics application. The BEM code is then used to calculate unknown boundary surface normal displacements and surface pressures from known exterior near Held pressures. And then the calculated surface normal displacements and surface pressures are again applied to the BEM in forward in order to calculate reconstructed field pressures. The initial exterior near field pressures are very well agreed with the later reconstructed field pressures. Only the same number of boundary surface nodes (1178) are used far the initial exterior pressures which are initially calculated by Finite Element Method (FEM) and BEM. Pseudo-inverse technique is used for the calculation of the unknown boundary surface normal displacements. The structural object is a tuning fork with 128.4 Hz resonant. The boundary element is a quadratic hexahedral element (eight nodes per element).

• The Journal of Asian Finance, Economics and Business
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• v.7 no.12
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• pp.1099-1110
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• 2020

This research tests the effects of institutional pressures, the use of performance measurement systems and accountability, and moderation effects of human resource capability between institutional pressures and the use of performance measurement systems in the Local Government institutions in Indonesia. The research aims to provide empirical evidence both quantitatively and qualitatively that isomorphism institutional pressures occurred in the scope of implementation of the performance measurement system and accountability in the public sector organizations and to show the importance of human resource capability enhancement in reducing external pressure impact. In addition, it tries to develop the correlation model of institutional pressures, human resource capability, implementation of the performance measurement system, and accountability of public sector organizations. The research used mixed methods with sequential explanatory design. The data collection used surveys and interviews in 209 regency/Special Region of Yogyakarta and Central Java local governments as samples. The research result indicated that the institutionalization process of the performance measurement is influenced by institutional pressures, especially coercive and mimetic pressures. Human resource capability was unable to weaken institutional pressures effects in the performance measurement system implementation. The research also proved that the use of a performance measurement system was able to improve local government institution accountability.

• Wind and Structures
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• v.26 no.3
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• pp.163-177
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• 2018

Tornadoes are one of the world's deadliest natural phenomena. They are characterized by short life span and danger. It has been observed through post-damage surveys that localities with large numbers of buildings suffer major damage during a tornado attack resulting in huge loss of life and property. Thus,it is important to study interfering buildings exposed to tornado-like vortices. The present study focuses on external and internal pressures developed on building models exposed to translating tornado-like vortices in the presence of an interfering building model. The effects of translating speed and swirl ratio of a tornado-like vortex on external and internal pressures for a principal building in the vicinity of an interfering building are investigated. Results indicate that external and internal pressures are enhanced or reduced depending on the location of the interfering building with respect to the principal building.

• Wind and Structures
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• v.7 no.5
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• pp.333-344
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• 2004

This paper illustrates application of the proper orthogonal decomposition (POD) and the autoregressive (AR) model to simulate large wind pressures due to gusts on a low-rise building. In the POD analysis, the covariance of the ensemble of large wind pressures is employed to calculate the principal modes and coordinates. The POD principal coordinates are modeled using the AR process, and the fitted AR models are employed to generate the principal coordinates. The generated principal coordinates are then used to simulate large wind pressures. The results show that the structure characterizing large wind pressures is well represented by the dominant eigenmodes (up to the first fifteen eigenmodes). Also, wind pressures with large peak values are simulated very well using the dominant eigenmodes along with the principal coordinates generated by the AR models.

• Geomechanics and Engineering
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• v.1 no.2
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• pp.155-168
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• 2009

Breakdown pressures obtained from the classic, linear elastic breakdown model are compared with the corresponding pressures obtained using a nonlinear material model. Compression test results obtained on sandstone and siltstone are used for that purpose together with previously formulated nonlinear model which introduces elasticity functions to address nonlinear stress-strain behaviour of rocks exhibiting stress-dependent mechanical properties. Linear and nonlinear collapse pressures are also compared and it is shown that material nonlinearities have significant effect on both breakdown and collapse pressures and on tangential stresses which control breakdown pressure around a borehole. This means that the estimates of ${\sigma}_H$ made using linear models give stress values which are different than the real values in the earth. Thus the importance of a more accurate analysis, such as provided by the nonlinear models, is emphasised. It is shown, however, that the linear elastic model does not necessarily over-predict borehole stresses and the opposite case can be true, depending on rock type and test interpretation.

• Asia pacific journal of information systems
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• v.24 no.1
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• pp.1-29
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• 2014

To provide a fundamental understanding on the inherent relationship between IT capabilities and sustainable firm heterogeneity, we investigate the dual roles that institutional pressures play, namely, as antecedents of IT capabilities and as moderator of the relationship between IT capabilities and IT innovation success, where IT innovation success plays a mediating role between IT capabilities and firm performance. The structural model was tested, and the results of the PLS analysis provided general support for the proposed hypotheses. IT capabilities had an indirect effect mediated by IT innovation success on firm performance. With IT activities assumed to be embedded in the institutional context, the dual roles of institutional pressures are verified. This study contributes to the literature on IT capabilities by considering both the determining role of institutional pressures on IT capabilities and the institutional context of the chain that connects IT capabilities to firm performance. The results suggest that a firm not only manages various institutional pressures to foster its IT capabilities but also adapts to different contexts with a certain level of institutional pressures to facilitate its IT capabilities and outperform its competitors, which could be sustained through IT innovation success.