Dynamics of structures

The dynamic behavior of rigid-block structures resting on a rigid foundation subjected to horizontal harmonic excitation is examined. For slender structures, the nonlinear equation of motion is approximated by a piecewise linear equation. Using this approximation for an initially quiescent structure, safe or no-toppling and unsafe regions are identified in an excitation amplitude versus excitation frequency plane. Furthermore, several possible modes of steady-state response are detected, and analytical procedures are developed for determining the amplitudes of the predominant modes and for performing stability analyses. It is shown that the produced stability diagrams can be beneficial to assessing the toppling potential of a rigid-block structure under a given amplitude-frequency combination of harmonic excitation; in this manner the integration of the equation of motion is circumvented.

Closure of "Rocking of Rigid Blocks Due to Harmonic Shaking"

SynOptics Communications Inc.

Written by a leader on the subject, Introduction to Geotechnical Engineering is first introductory geotechnical engineering textbook to cover both saturated and unsaturated soil mechanics. Destined to become the next leading text in the field, this book presents a new approach to teaching the subject, based on fundamentals of unsaturated soils, and extending the description of applications of soil mechanics to a wide variety of topics. This groundbreaking work features a number of topics typically left out of undergraduate geotechnical courses.

Geotechnical Engineering: Unsaturated and Saturated Soils

Automatic detection of atrial fibrillation using stationary wavelet transform and support vector machine

Studies on cyclic behavior of tripod suction bucket foundation system supporting offshore wind turbine using centrifuge model test

The authors present a method for calculating a mooring line’s tension and angle of inclination at the anchor pad eye to analyze the behavior of a mooring line embedded in sand. They adopted the governing equation from a previous study for clay and reanalyzed the frictional and bearing resistances. The authors performed a number of centrifuge tests at two anchor depths while maintaining relative densities of 76 or 51% in the cylindrical test box to validate the proposed analytical method. The analytical solutions agreed well with the test results and the results of the simplified method. The authors conducted a parametric study to evaluate the effects of various factors on the behavior of an embedded mooring line in sand, including the depth of the attachment point, the internal friction angle of sand, the submerged unit weight of sand, the angle of the mooring line on the seabed, and the self-weight and nominal diameter of the mooring line. The results demonstrated that the proposed analytical met...

Profile and Frictional Capacity of a Mooring Line Embedded in Sand via Centrifuge Model Testing

The revolutionary improvements in low power devices and lightweight network protocols are making the mobile healthcare engage attentions. However there are some obstacles to realize mobile healthcare. Connectivity of miniaturized wearable sensors of the body area network (BAN) to the Internet is one of the most important issues in realizing mobile healthcare system. Interoperability is also important in order for sensor data not to be isolated in a local system. In this paper, we designed our mobile healthcare system resolving connectivity and interoperability issues. In our mobile healthcare system, body sensors are integrated by leveraging RESTful web service via CoAP over IPv6, enabling web-based access from browsers. Extended EPCglobal architecture was used for our system to enable sharing of sensor data among applications with different domain through the standardized protocol. We developed two applications, patient browser and EagleEye, to prove its feasibility.

The patient-centric mobile healthcare system enhancing sensor connectivity and data interoperability

Nonlinear system identification on shallow foundation using Extended Kalman Filter

Site response analyses were peformed based on equivalent linear technique using the shear wave velocity profiles of 162 sites collected around the Korean Peninsula. The she characteristics, particularly the shear wave velocities and the depth to bedrock, are compared to those in the western United States. The site coefficients of short period and the long period obtained from this study were significantly different compared to 1997 Uniform Building Code (1997 UBC). underestimated the motion in shot period ranges and overestimated the motion in mid period ranges in Korean seismic guideline. It is found that the existing Korean seismic design code were is required to be modified considering geological site conditions in Korea for the reliable estimation of sue amplification. Problems of the current seismic design code were dicussed in this paper and the development of site classification method and modification of desing response spectra were discussed in the companion papers(II-Development of Site Classification System and III-Modification of Dosing Response Specra).

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Development of Site Classification System and Modification of Design Response Spectra considering Geotechnical Site Characteristics in Korea (I) - Problem Statements of the Current Seismic Design Code

Dong-Soo Kim

Papers

Studies on cyclic behavior of tripod suction bucket foundation system supporting offshore wind turbine using centrifuge model test

Profile and Frictional Capacity of a Mooring Line Embedded in Sand via Centrifuge Model Testing

The patient-centric mobile healthcare system enhancing sensor connectivity and data interoperability

Nonlinear system identification on shallow foundation using Extended Kalman Filter

Development of Site Classification System and Modification of Design Response Spectra considering Geotechnical Site Characteristics in Korea (I) - Problem Statements of the Current Seismic Design Code