Analysis and Design of Lens Antenna Systems for Applications at Millimeter and Sub-millimeter Wavelengths

In recent decades, dielectric lens antennas have been more and more adopted and developed for sensing and imaging applications at sub-millimeter (sub-mm) wavelengths because they can achieve high gain while keeping their physical size and weight acceptable at these wavelengths. More recently, as low-loss and low-cost lens materials have become...

Investigating the Relationship Between Clinical Image Characteristics and Mechanical Properties of In Vitro Thrombi in Acute Ischemic Stroke: A Comprehensive Analysis About Acute Ischemic Stroke

Stroke, currently ranked as the second leading cause of mortality and the most prevalent source of enduring disability, imposes significant societal and economic consequences. These consequences encompass the necessity for extended care, rehabilitation, and the economic burdens associated with lost productivity. In the diagnostic process,...

Influence of fiber orientation on the mechanical responses of engineering cementitious composite (ECC) under various loading conditions

The mechanical performance of engineered cementitious composite (ECC) depends greatly on fiber orientation and distribution. In this paper, the effect of fiber orientation on ECC's mechanical properties was investigated using two different casting methods: a flow-induced casting was used to enhance the fiber orientation within ECC mixture and...

Focal Plane Array of Shaped Quartz Lenses for Wide Field-of-view Sub-millimeter Imaging Systems

Large format focal plane arrays (FPAs) of dielectric lenses are promising candidates for wide field-of-view submillimeter imagers. In this work, we optimize the scanning gain of such imagers via shaping lens surfaces. We develop an optimization procedure using a field correlation technique between the fields generated by a reflector on the...

Investigation of concrete crack kinematics through probability density field of the location of acoustic emission events

Monitoring or identifying structural cracks is crucial for assessing the health of existing concrete structures. Key information about structural cracking encompasses the location of the crack and its kinematics, which include movements perpendicular and parallel to the crack face. Acoustic emission (AE) is a sensitive technique for detecting...

Fatigue life and cracking characterization of engineered cementitious composites (ECC) under flexural cyclic load

This paper presents a study on cracking characterization of engineered cementitious composites (ECC) under flexural cyclic load using digital image correlation (DIC) technique. Five stress levels, namely 0.65, 0.75, 0.8, 0.85 and 0.9 of the flexural strength, were applied. Strain map at the side surface was obtained by DIC and used to drive...

Identification of Stop Criteria for Large-Scale Laboratory Slab Tests Using Digital Image Correlation and Acoustic Emission

Advanced monitoring methods are required to identify stop criteria in proof-load tests. In this study, the combined methodology of two-dimensional digital image correlation and acoustic emission is investigated for its applicability for future implementation in field tests. The two monitoring systems are deemed to provide valuable insight...

Monitoring Shear Behavior of Prestressed Concrete Bridge Girders Using Acoustic Emission and Digital Image Correlation

In the Netherlands, many prestressed concrete bridge girders are found to have insufficient shear–tension capacity. We tested four girders taken from a demolished bridge and instrumented these with traditional displacement sensors and acoustic emission (AE) sensors, and used cameras for digital image correlation (DIC). The results show that AE...

Temporal information gathering process for node ranking in time-varying networks

Many systems are dynamic and time-varying in the real world. Discovering the vital nodes in temporal networks is more challenging than that in static networks. In this study, we proposed a temporal information gathering (TIG) process for temporal networks. The TIG-process, as a node's importance metric, can be used to do the node ranking. As...