Miracle-dz/UniFAR-FTUs huggingface dataset:
Theory of signal degradation in semiconductor laser amplifiers in direct detection systems

Theoretical studies are carried out on long haul direct detection optical fiber communication systems, with inline optical semiconductor amplifier repeaters. Calculations are made of the noise, eye diagrams, and bit-error-rate characteristics of lightwave systems with optical amplifiers. Indications are given of the effect of amplifier characteristics such as spontaneous noise and signal distortion due to gain saturation on the system performance. The nonlinear process within semiconductor laser amplifiers leads generally to pulse amplitude-temporal distortions due to gain saturation. This theoretical study demonstrates that the system penalty caused by these nonlinear effects appears progressively as the optical input power at each amplifier is increased. For example, nonregenerated fiber transmission using traveling wave semiconductor laser amplifiers was simulated, and results obtained at 0.5 and 2.5 Gb/s are presented. In order to improve the system performance, the influence of structure and bulk dimensions of the amplifier cavity is also considered. >
Calculation and validation of thermomechanical stresses in flip chip BGA using the ATC4.2 test vehicle

We report the first in situ measurements of thermomechanical stresses in a 1000 I/O 250 /spl mu/m pitch piezoresistive flip chip test chip assembled to a 755 I/O 1.0 mm pitch 35 mm Ball Grid Array (BGA). The BGA substrates employed "build-up" dielectric layers containing micro-vias over conventional fiberglass laminate cores. Experimental data, which include in situ stress and die bending measurements, were correlated to closed form and Finite Element Method (FEM) calculations. Cracking and delamination were observed in some of the experimental groups undergoing temperature cycling. Through use of bounding conditions in the FEM simulations, these failures were associated with debonding of the underfill fillet from the die edge that caused stresses to shift to weaker areas of the package.
The effects of harmonics on differential relay for a transformer

The use of nonlinear devices such as rectifiers, converters, power supplies, and other devices utilizing solid state switching have been increased in industry. These equipments have deteriorated the power quality. This deterioration causes the increase of power loss, resonance problem, insulation deterioration, and even safety problems for system apparatus. This paper aims at analyzing and probing into the influences of harmonics on a differential relay. First it probes the operation of a CT in the frequency domain. Then, it analyzes and compares the mathematical model, which is constructed by using EMTP, and the test results. There are many factors to be considered in differential protection design and application for a transformer. This paper only analyzes the influential phenomenon of harmonics to a differential relay. The results of this research can be valuable references for applying and designing differential relay protection.
Urban RAT: New Tool for Virtual and Site-Specific Mobile Rapid Data Collection for Seismic Risk Assessment

AbstractThe Urban Rapid Assessment Tool (RAT) integrates recent advances in virtual environments and mobile smart devices to facilitate the rapid visual screening (RVS) of building structural parameters outlined in FEMA 154 and FEMA 310. These advanced parameters support Tier-1 and Tier-2 earthquake loss estimations in programs such as Hazus and CanRisk. Urban RAT includes two software components that use a common database schema: Urban RAT Desktop integrates the virtual environment of Street View within the geographic information system ArcGIS and, Urban RAT mobile, an equivalent on-site data collection application for the Android operating system. Structural parameters observed on a sample of 113 buildings using both Urban RAT Desktop and Urban RAT Mobile show significant agreement. As such, virtual assessment is a viable proxy for field-based RVS, making Urban RAT effective and efficient for rapid structural data collection to support detailed loss estimation studies in urban regions. Developed and tes.
DynPaC: Coarse-Grained, Dynamic, and Partially Reconfigurable Array for Streaming Applications

Coarse-grained reconfigurable arrays (CGRAs) provide higher flexibility than application-specific integrated circuits (ASICs) and higher efficiency than fine-grained reconfigurable devices such as Field Programmable Gate Arrays (FPGAs). However, CGRAs are generally designed to support offloading of a single kernel. While their design, based on communicating functional units, appears to naturally suit streaming applications composed of multiple cooperating kernels, current approaches only statically partition the resources across kernels. However, streaming applications often are data-dependent, leading to variable kernel execution times depending on the input data and impacting the throughput of the entire pipeline if resources are statically allocated. Therefore, in this paper, we discuss the design of DynPaC — a coarse-grained, dynamically, and partially reconfigurable array for data-dependent streaming applications. We discuss the required software and hardware components to manage partial dynamic reconfiguration. We demonstrate that by supporting partial dynamic reconfiguration, we can obtain an average speedup of 1.44× for a representative set of applications w.r. t. static partitioning, with a limited area overhead (6.4% of the entire chip).
Computer Automation of Conventional Triaxial Equipment

This paper provides objective guidance on the conversion of existing manual triaxial testing equipment to computer control. An approach called adaptable automation is introduced to facilitate the conversion process. This approach consists of modifying the four basic building blocks of the triaxial system for integration into a computer-automated system and adding components needed for automation which were not part of the manual system. Recommendations are made on necessary changes to the triaxial building blocks, and examples are given from the actual conversion of a largely manual triaxial apparatus. New components required for the automated system are an analog-to-digital conversion device, digital-to-mechanical hardware, and a personal computer with test control software. Performance guidelines for selecting equipment are reviewed as are considerations when developing the software. Methods are described for evaluating the converted system's performance, and typical evaluation results are shown. The paper concludes that, while development of a prototype converted system can be costly and require considerable knowledge of system components, cost savings will be realized as additional prototype-based systems are brought online and system capabilities expanded. More importantly, the converted system allows existing customized testing procedures and hardware to remain in place.
Switching Transient Shaping by Application of a Magnetically Coupled PCB Damping Layer

An increasing number of power electronic applications require high power density. Therefore, the switching frequency and switching speed have to be raised considerably. However, the very fast switching transients induce a strong voltage and current ringing. In this work, a novel damping concept is introduced where the parasitic wiring inductances are advantageously magnetically coupled with a damping layer for attenuating these unwanted oscillations. The proposed damping layer can be implemented using standard materials and printed circuit board manufacturing processes. The system behavior is analyzed in detail and design guidelines for a damping layer with optimized RC termination network are given. The effectiveness of the introduced layer is determined by layout parasitics which are calculated by application of the Partial Element Equivalent Circuit (PEEC) simulation method. Finally, simulations and measurements on a laboratory prototype demonstrate the good performance of the proposed damping approach.
Analysis of electromagnetic band‐gap waveguide structures using body‐of‐revolution finite‐difference time‐domain method

Study of electromagnetic band‐gap (EBG) structures has become a hot topic in computational electromagnetics. In this article, some EBG structures integrated inside a circular waveguide are studied. They are formed by a series of air‐gaps within a circular dielectric‐filled waveguide. A body‐of‐revolution finite‐difference time‐domain (BOR‐FDTD) method is adopted for analysis of such waveguide structures, due to their axial symmetric properties. The opening ends of the waveguide are treated as a matched load using an unsplit perfectly matched layer technique. Excitations on a waveguide in BOR‐FDTD are demonstrated. Numerical results of various air‐gap lengths with respect to the period of separation are given, showing an interesting tendency of EBG behavior. A chirping‐and‐tapering technique is applied on the EBG pattern to improve the overall performance. The proposed EBG structures may be applied into antenna structures or other system for unwanted signal suppression. Results show that the BOR‐FDTD offers a good alternative in analyzing axial symmetric configurations, as it offers enormous savings in computational time and memory comparing with a general 3D‐FDTD algorithm. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2201–2206, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22668
Product modularity: Definitions and benefits

The present paper presents an overview of existing research on the definition of modular product design and its benefits. Modularity has been discussed in terms of product development for quite some time. In recent years, the discussions have increased. The development of metrics and methods has also increased. However, these metrics and methods are often based on different definitions and varying goals. Understanding what modularity is and why it is useful is the foundation of modular product design. The purpose of this paper is to examine the existing literature and draw conclusions about where consensus exists and areas for further discussion. The relationship to product platform planning is also shown. This overview shows that there is a clear consensus on the point of independence of form and function. Within this definition, there is a strong pressure to extend modularity beyond form-function concerns and out across the life-cycle. Additionally, there is pressure to look at similarity or compatibility within modules in addition to independence. The benefits of modular design are widely advocated. When taken across a product family, many are quite intuitive. There has been no work to show these benefits in the modularity of singular products over their design life. It is hoped that this research will highlight the present inconsistencies in the field of modular product design and put forward some critical questions, which will shape future research into this field.
Proviso on the unconditional stability criteria for linear twoport

The proviso imposed by Rollett [1962] on the well-known stability criteria for linear twoports is examined and redefined as the requirement that at least one set of immittance parameters must have no RHP (right-half plane) poles. It is shown that the proviso can be interpreted as the extreme cases of a newly introduced proviso that requires that the S-parameters defined for at least one pair of arbitrary positive reference impedances have no RHP poles. The new proviso means that the twoport must be stable for at least one pair of arbitrary positive resistance terminations. Since S-parameters are much easier to measure than immittance parameters at microwave frequencies and their direct measurability is an indication of the absence of RHP poles, the new proviso allows us to apply the stability criteria to measured circuits less consciously of the proviso. >
Investigation of drivers' diversion responses to urban freeway variable message signs displaying freeway and local street travel times

This paper explores urban freeway users' diversion responses to D-VMS (a new type of freeway variable message sign that explicitly provides travel times for both freeways and local streets) in the context of China. An on-site stated preference questionnaire survey was conducted to collect behavioral data. Four types of binary probit models were estimated to identify the factors that influence diversion behavior: the model with only constant coefficient and the models with ‘normal’, ‘truncated normal’, and ‘log-normal’ random coefficients. The three models with random coefficients accommodate heterogeneous preferences for travel time savings among drivers. The study shows that drivers' en route decisions on diverting from a freeway to local streets can be significantly influenced by D-VMS and the extent of the D-VMS impacts depends on driver characteristics, local street characteristics, and D-VMS messages. Main findings regarding D-VMS impacts are (1) travel time savings and drivers' years of driving experience serve as positive factors in diverting and (2) the number of traffic lights on the street, frequency of urban freeway use, being a mid-age driver, and an employer-provided car driver serve as negative factors in diverting. In terms of heterogeneous preference modeling, likelihood ratio tests show the three models with random coefficients obtain higher goodness of fits, and preliminary evidence is given that a small portion of drivers are insensitive to travel time savings indicated by D-VMS and persist in using urban freeways. The findings of this study have implications for the design and operation of D-VMS and for further effort on driver behavior modeling.
Using CYGNSS Data to Map Flood Inundation during the 2021 Extreme Precipitation in Henan Province, China

On 20 July 2021, parts of China’s Henan Province received the highest precipitation levels ever recorded in the region. Floods caused by heavy rainfall resulted in hundreds of casualties and tens of billions of dollars’ worth of property loss. Due to the highly dynamic nature of flood disasters, rapid and timely spatial monitoring is conducive for early disaster prevention, mid-term disaster relief, and post-disaster reconstruction. However, existing remote sensing satellites cannot provide high-resolution flood monitoring results. Seeing as spaceborne global navigation satellite system-reflectometry (GNSS-R) can observe the Earth’s surface with high temporal and spatial resolutions, it is expected to provide a new solution to the problem of flood hazards. Here, using the Cyclone Global Navigation Satellite System (CYGNSS) L1 data, we first counted various signal-to-noise ratios and the corresponding reflectivity to surface features in Henan Province. Subsequently, we analyzed changes in the delay-Doppler map of CYGNSS when the observed area was submerged and not submerged. Finally, we determined the submerged area affected by extreme precipitation using the threshold detection method. The results demonstrated that the flood range retrieved by CYGNSS agreed with that retrieved by the Soil Moisture Active Passive (SMAP) mission and the precipitation data retrieved and measured by the Global Precipitation Measurement mission and meteorological stations. Compared with the SMAP results, those obtained by CYGNSS have a higher spatial resolution and can monitor changes in the areas affected by the floods over a shorter period.
Acoustic Source Localization via Advanced TDoA for Self-Organization Wireless Sensor Networks

Wireless Sensor Networks (WSNs) enable susceptible sensing of the environment, offering unprecedented opportunities for observing the physical world. Acoustic source localization is an interesting topic with many possible application areas, such as intruder detection, sniper localization, automatic tracking of speakers and so on. Many existing algorithms are on the premise that the exact coordinates of sensor nodes are already known. In this paper, we propose a vector-based advanced TDoA algorithm that would calibrate the coordinate of the acoustic source by the non-prepositioned nodes. In the meanwhile, the portable sensor nodes would adjust themselves through the feedback of the estimated positions as well. Finally, we show that the proposed mechanism has high accuracy through experiments.
A Communication Framework: A Babel Fish for Instructional Game Designers

“…if you stick a Babel fish in your ear you can instantly understand anything said to you in any form of language. ” Hitchhiker’s Guide to the Galaxy. Designing serious games for learning is undoubtedly the most complex, multidisciplined technology-based challenge existing in our training world and is increasingly popular for military training. Somewhat of a rift has developed between game designers (including developers, graphic artists, and designers) and instructional designers. Some assert that instructional designers take all of the fun out of a game (Aldrich, 2005) and some accuse game designers of creating only “eye candy” (Squire, 2008). As part of a larger study for the Office of Naval Research, Capable Manpower Future Naval Capability Program, we are examining learning game design. In particular, we are studying how the various disciplines conceptualize serious game design and how to facilitate communication among the disciplines. This will lead to a model for learning game design that accommodates the needs of all learning game design disciplines. This paper describes our efforts to understand the perspectives of different design disciplines and the impact on a communication framework for instructional game design.
Neoliberalism and Religion in Latin America

The term “neoliberalism” has variable and broad meanings. It has even been suggested that we should dispense with the term altogether. However, in this text, I defend that we can find a very powerful concept of neoliberalism in the works of Dardot-Laval, and Brown. These thinkers show us that neoliberalism needs to be conceived as a rationality that produces a specific kind of human subjectivity, namely, the neoliberal Homo Oeconomicus or the Homo Neoliberalis. Such a concept is, in addition, crucial to understand the most recent and visible changes in Latin American religiosity, that is, the so-called “Latin American Protestant Turn”. This turn, as has been noted, should be more precisely called the “Latin American Pentecostal Turn”. Based on empirical studies that describe the main elements of this turn, I describe what seems to be the principal traits of the religiosity of the Latin American Homo Neoliberalis.
Exploring two models of emotion regulation: how strategy use, abilities, and flexibility relate to well-being and mental illness

ABSTRACT Background and Objectives The process model of emotion regulation (ER) focuses on strategies used to manage emotions, while the abilities model emphasizes the extent one adaptively responds to negative emotions. We sought to clarify the relationships between components of ER based on both of the abilities (i.e., dysregulation) and process (i.e., strategy use) models, as well as ER flexibility (i.e., choosing the optimal strategy for a given situation) with well-being (happiness, flourishing), internalizing symptoms (depression, anxiety), and disordered eating. Gender differences were explored. Design and Method Participants included 612 undergraduate students (M age = 20.24) who completed questionnaires measuring ER, well-being, and mental illness. Structural equation modeling was used on cross-sectional data to explore the associations between ER and psychological outcomes. Results Dysregulation was associated with reduced well-being and greater psychopathology. In terms of strategy use, reappraisal was related to greater well-being and fewer internalizing symptoms, while the opposite relationships were found for suppression. Suppression was also linked to disordered eating. ER flexibility was related to well-being for men only. Further, dysregulation had the largest association with all outcomes. Conclusions Findings suggest that ER abilities may underlie other components of ER and are most central to mental health and illness.
Circular Economy Development in the Construction Sector in Japan

The circular economy (CE) is about a system-level change towards sustainability, and it aims at keeping products, components, and materials at their highest utility and value at all times, covering both technical and biological cycles. This study aimed at exploring, discovering, describing, and synthesizing the characteristics of CE development in the construction sector in Japan based on the perspectives of sectoral organizations and focusing on the following themes: (1) sustainable production; (2) sustainable consumption; (3) creation and maintenance of value in a CE; (4) CE innovations; (5) CE of material and energy use; (6) technological, economic, and social barriers to CE; (7) CE guidance; and (8) specific CE aspects in the construction sector. This study applied a qualitative research approach, including a questionnaire survey as the specific method. This study addressed a gap in the research and helps to improve understanding of the CE development priorities based on the perspectives of organizations operating in or related to the construction sector in Japan. The findings indicate that the priority CE development focus areas in the construction sector in Japan encompass, for example, the use of sustainable and renewable raw materials; consumer awareness; and the design, use, and manufacturing of sustainable, recyclable, reusable, and repairable products, components, and materials. The barriers to CE that need to be overcome encompass, for example, the lack of general knowledge about circular economy opportunities and of seeing the “big picture” as well as issues related to economic benefits and the development of CE and sustainability-oriented products, components, and materials. Particularly important CE aspects in the construction sector include the maintenance of existing buildings; sustainability and the long-life cycles of products, components, and materials; CE-oriented product design; and sustainability criteria and cooperation between parties covering the whole life cycle of construction.
A 1.8-V operation RF CMOS Receiver Front-End for WLAN/MAN

This paper describes a CMOS direct-conversion receiver front-end for 5GHz wireless LAN/MAN. Sub-harmonic mixing is used for down-conversion to minimize the DC-offset due to LO-leakage. The residual DC-offset is cancelled by a digital-to-analog converter at the output of mixer. Band-gap reference generates required bias voltages and currents for each block. Serial-to-parallel interface (SPI) circuit is used to provide the various control signals such as gain-control of low-noise amplifier (LNA). To minimize the DC-offset due to LO selfmixing, sub-harmonic mixing is used for down-conversion. For quadrature down-conversion with sub-harmonic mixing, octa-phase LO signals are generated by octa-phase shifting network. Implemented in a 0.18 m CMOS technology, the receiver dissipates 62mA from a 1.8V supply voltage and has 3.1dB noise figure (NF) and -13dBm input third-order intercept point (iIP3).