Miracle-dz/UniFAR-FTUs huggingface dataset:
Seismic Fragility Analysis of Cable-Stayed Bridges Considering Different Sources of Uncertainties

Seismic fragility analysis is a complex process involving different sources of uncertainties. In this paper, an alternative procedure for seismic fragility analysis based on the uniform design method (UD) is proposed. UD is used to generate a reasonable sample to build probabilistic seismic demand models (PSDMs), which are used to generate the fragility curves of a cable-stayed bridge. Sensitivity analyses of different uncertainties are carried out by comparison of the fragility curves for different components. It is concluded that (1) the UD method can consider different sources of uncertainties in fragility analysis with reasonable accuracy; (2) the bridge system is more fragile than any component of bridges; and (3) the damage probability of fragility considering uncertainty in the ground motion, geometry, and material is larger than that considering only the uncertainty in the ground motion.
Pattern placement error due to resist charging effect at 50kV e-beam writer: mechanism and its correction

By the development of double exposure technique and the EUV lithography the pattern placement error of photomask is interested because of its impact on size and position of wafer pattern. Among various sources to induce the pattern placement error, we have focused on the resist charging effect and shown that the resist charging effect generates pattern position error and CD variation. Based on experiment and simulation, we present quantitatively the dependence of position error on pattern density, pattern shape, and writing order. Furthermore, we have discussed the model to describe the charging effect and its agreement with experiment, and correction method to remove the resist charging effect.
The Impact of Use of Dual Monitor Screens on 3D Head–Neck Posture and Activity of Neck Muscles

OCCUPATIONAL APPLICATIONS Computers with dual monitor screens are being increasingly used at many workplaces. Altered screen layout and increased viewing space associated with dual monitor screens may affect head–neck working postures and the activity of neck muscles. However, this problem has not been investigated in the past, and standard guidelines based on empirical data are not available for setting up a computer workstation with dual monitor screens. The present study compared the effects of single versus dual monitor screens on 3D head–neck postures and the activity of neck muscles in computer users. The results of this study have demonstrated that working on a video display unit workstation with dual monitor screens involved more rotated, asymmetric head–neck postures and higher activation of the anterior neck muscles than a video display unit workstation with a single monitor screen. TECHNICAL ABSTRACT Background: Among workstation design factors, placement of the computer monitor screen is the most frequently identified risk factor for neck and shoulder pain among video display unit users. One of the recent changes in video display unit workstation design that may influence the position of computer monitor screens is the use of dual monitors. Some studies have shown that user performance and efficiency was positively affected by the use of dual monitor screens; however, the effect of use of dual monitor screens on the biomechanical behavior of the head-neck region is currently unknown. Purpose: This study was aimed at understanding the effect of single versus dual monitor screens on 3D head–neck postures and the activity of neck muscles. Method: Ten healthy participants performed three types of video display unit tasks: (1) reading for 10 minutes, (2) typing for 5 minutes, and (3) performing search and find tasks for 10 minutes using single and dual monitor screens. An inertial motion-capture system was used to measure 3D head–neck postures. Activity of sternocleidomastoid and cervical trapezius muscles was recorded bilaterally using surface electromyography. Results: Use of dual monitor screens significantly increased head–neck rotation by 9.0° compared to the single monitor screen. The range of motion of head–neck rotation increased significantly by 8.4° using dual monitor screens compared to the single monitor screen. Corresponding to the increase in the head–neck rotation, a contralateral increase in the activity of the right sternocleidomastoid muscle was observed with the dual monitor screen layout. Activity of cervical trapezius muscle was not affected by the type of monitor layout. Conclusions: Increased activation of anterior neck muscles caused by asymmetrical, more rotated head–neck postures while operating a video display unit workstation with dual monitor screens may increase the risk of neck musculoskeletal disorders, especially with prolonged computer use.
Cognitive work analysis and design: current practice and future practitioner requirements

Cognitive work analysis (CWA) is a unique analytical framework which provides analysis information to inform system design. However, the literature describing CWA applications indicates that its use in design is not straightforward. An online survey was used to gather information from CWA practitioners about how they have used CWA in design applications and to gather their views and attitudes on aspects of CWA and design. The survey found that there was no typical means of using the outputs of CWA within design processes across survey respondents. Over half of the respondents indicated that there is a need for an additional approach or method to enhance the contribution of CWA to design. It is concluded that the field could benefit from the development of an additional design approach, with associated guidance, to assist in using the outputs of CWA in design processes.
Rapid Decay of a Timber Footbridge and Changes in Its Modal Frequencies Derived from Multiannual Lateral Deflection Measurements

AbstractLateral deflections of a timber pedestrian bridge in Patras, Greece, excited by pedestrians were measured using a robotic total station (RTS) in six annual surveys. Analysis of the data indicated a drop of 1.6 Hz in the natural frequencies of the bridge between 2007 and 2008 and then a gradual drop of approximately 8% between 2008 and 2012. This frequency drop was consistent with signs of decay, accelerometer data, and a drop in the natural frequencies along the vertical axis, and was most probably prompted by a strong earthquake and especially by an extraordinary (for the area) icing event. The overall changes in the response of the bridge to dynamic loads were consistent with the feelings of discomfort for pedestrians crossing this bridge. This is probably the first case of repeated measurements of deflections documenting deterioration of the structural health of a bridge at this intensity and scale of time.
Numerical model to study the valve overlap period in the Wärtsilä 6L 46 four-stroke marine engine

Numerical model to study the valve overlap period in the Wärtsilä 6L 46 four-stroke marine engine In this paper, a CFD (Computational Fluid Dynamics) analysis was carried out to study the Wärtsilä 6L 46 medium-speed, four-stroke marine engine. For the purpose, the commercial software ANSYS Fluent 6.3 was employed. The aim is to analyze the scavenging of gases, especially during the valve overlap period. Particularly, the pressure, velocity and mass fraction fields were numerically obtained. In order to validate the CFD results, the in-cylinder pressure was successfully compared to experimental measurements for the exhaust, intake and compression strokes of the cylinder operation. This model can be used in future works to improve the performance of these engines because the information provided is very useful to identify regions in which the pressure, velocity or distribution of gases are inadequate. Besides, to compute the quantity of burnt gases which remain inside the cylinder, fresh charge which is expelled through the exhaust valves and study the influence of parameters such as the exhaust and intake pressures, engine speed, cam profile design, etc.
Predicting downtime costs of tracked hydraulic excavators operating in the UK opencast mining industry

This paper describes the development of a model to predict the hourly cost of downtime (using regression equations) for tracked hydraulic excavators operating in the UK opencast mining industry. A three-stage process was utilized for the model's development. The first stage predicted machine cycle times, the second predicted hire costs per hour and the third used the outputs of the first two to forecast the cost of breakdown. Both cycle time and hire cost models were revealed to be good predictors, as exhibited by the ‘high’ R2 values of 0.86 and 0.95, respectively. A plant expert employed within the Defence Logistics Organisation, UK Ministry of Defence, validated these regression models and the process by which downtime costs were predicted. Future research work will aim to enhance the predictive ability of the models developed, expand the research to cover other machine types, and reproduce the findings in graphical and tabular format to improve the interpretation of information generated.
The Regional Deterrence Ship (RDS 2010)

This paper describes the design of a Regional Deterrence Ship (RDS 2010) for the 2010 timeframe. The requirements for the design were for a ship to operate in littoral areas of the world with a mission of deterring regional conflicts and of hampering the efforts of the aggressor in such a conflict. In addition the ship's mission included the evacuation of friendly personnel as hostilities become likely. The problem countering the littoral threat during times of constrained budgets is addressed. Top level requirements for the design, generated in parallel with From the Sea [1], were used to set the design goals. The paper describes the manner in which littoral warfare changes the nature of the challenges faced by Navy surface combatants, including a ship such as the RDS 2010. A number of factors become more crucial design concerns than for blue water ships, including reduced reaction times, likelihood of attack from hidden land sites, shallow water mines and shallow water USW. Certain other factors become less critical in littoral areas and this also has ship design impacts. While some present ship designs can perform some of the tasks needed in a littoral warfare/regional conflict environment, none represents a completely integrated design (hull, mechanical & electrical ; combat systems ; fiscal and manning constraints ; reduced vulnerability; robust self-defense, etc.) for a vessel stationed in waters that, without warning, can become hostile. After describing the mission requirements to which the RDS 2010 was designed, the paper discusses the controlling design philosophy and decisions and describes the process used to assess threats to the ship. The process of combat system selection, against the backdrop of expected threat scenarios, is described and the intended approach to integration of the combat system is discussed. In recognition that decreased reaction times and surprise attacks are likely to threaten a ship engaged in regional deterrence, discussions of features intended to reduce ship vulnerability and crew casualties are presented in the paper. A description of the characteristics of the final design is presented and accompanied by a design evaluation. The authors also present suggestions for further investigation of promising design features and technologies for employment in such a ship. The paper includes a discussion of lessons learned in the process of producing the design and includes appropriate acknowledgments. The design was performed at the Naval Postgraduate School under the direction of author Calvano by a group of four officer students, which included author Riedel.
Factors Affecting Development of Huff Curves

ABSTRACT HUFF curves, which describe the variation in storm hyetographs, are sometimes used for design storms with models that provide estimates of runoff volume, peak flow, erosion, and water chemistry. However, factors that may affect the development of Huff curves have not been studied. Therefore, the effects of three factors that affect storm identification on Huff curves were investigated: sampling interval of precipitation data (3 and 60 min), method of identifying storms using the minimum (critical) dry-period duration between rainfall periods (rank correlation and exponential methods), and season of year. The effect of sampling interval on Huff curves is minor, allowing the use of more readily available hourly precipitation data by practicing engineers. The method of identifying individual storms using the critical duration of dry periods between rainfall periods also has a minor effect, in spite of large differences between critical duration estimates, making Huff curves relatively insensitive to estimates of critical duration. There is a significant effect of season of year on Huff curves. Huff curves have potential for more widespread practical use as design storms.
Ion-implanted high microwave power indium phosphide transistors

Encapsulated rapid thermal annealing (RTA) has been used in the fabrication of indium phosphide (InP) power metal-insulator-semiconductor field-effect transistors (MISFETs) with ion-implanted source, drain, and active channel regions. The MISFETs had a gate length of 1.4 mu m. Six to ten gate fingers per device, with individual gate finger widths of 100 or 125 mu m, were used to make MISFETs with total gate widths of 0.75, 0.8, or 1 mm. The source and drain contact regions and the channel region of the MISFETs were fabricated using silicon implants in semi-insulating InP at energies from 60 to 360 keV with doses from 1*10/sup 12/ to 5.6*10/sup 14/ cm/sup -2/. The implants were activated using RTA at 700 degrees C for 30 s in N/sub 2/ or H/sub 2/ ambients using a silicon nitride encapsulant. The high-power, high-efficiency MISFETs were characterized at 9.7 GHz, and the output microwave power density for the RTA conditions used was as high as 2.4 W/mm. For a 1-W input at 9.7 GHz gains up to 3.7 dB were observed, with an associated power-added efficiency of 29%. The output power density was 70% greater than that reported for GaAs MESFETs. >
Connecting engineering operations to strategic management: a framework for decision making in engineering offshoring

This paper investigates the implications for management and engineering functions and strategies when the product development process is globalised. Five case studies of Danish multinational corporations were conducted. The findings showed that offshoring engineering presented companies with challenges to both management and engineering. These challenges are addressed by management at the operational level. However, this resulted in both positive and negative impacts. We propose this is because there is a decoupling between global engineering operations and the strategic level of the organisation. The Global Decision-Making (GDM) framework described here is a decision-making framework for engineering offshoring decisions for product development activities. The framework proposes that risks in engineering offshoring can be reduced by connecting engineering operations to strategic management. This paper, built upon empirical data, provides a framework wherein to view engineering offshoring which both strengthens the academic field and responds to the needs of practitioners.
Estimating Evapotranspiration using Artificial Neural Network

This study investigates the utility of artificial neural networks (ANNs) for estimation of daily grass reference crop evapotranspiration (ETo) and compares the performance of ANNs with the conventional method (Penman–Monteith) used to estimate ETo. Several issues associated with the use of ANNs are examined, including different learning methods, number of processing elements in the hidden layer(s), and the number of hidden layers. Three learning methods, namely, the standard back-propagation with learning rates of 0.2 and 0.8, and backpropagation with momentum were considered. The best ANN architecture for estimation of daily ETo was obtained for two different data sets (Sets 1 and 2) for Davis, Calif. Using data of Set 1, the networks were trained with daily climatic data (solar radiation, maximum and minimum temperature, maximum and minimum relative humidity, and wind speed) as input and the Penman–Monteith (PM) estimated ETo as output. The best ANN architecture was selected on the basis of weighted sta.
Determining inventory levels in a CONWIP controlled job shop

We extend the concept of CONWIP control to a job shop setting, in which multiple products with distinct routings compete for the same set of resources. The problem is to determine the fixed overall WIP level and its allocation to product types (WIP mix) to meet a uniformly high customer service requirement for each product type. We formulate an optimization problem for an open queuing network model in which customer orders pull completed products from the system. Then, assuming heavy demand, we derive a throughput target for each product type in a closed queuing network and provide a simple heuristic to find a minimum total WIP and WIP mix that will achieve an operating throughput close to this target. In numerical examples, the WIP mix suggested by this approach achieves the customer service requirement with a relatively low total WIP.
Feto-Maternal Outcomes Of Hypertensive Disorders Of Pregnancy In Yekatit-12 Teaching Hospital, Addis Ababa, Ethiopia: A Retrospective Study

Background In resource poor countries, hypertensive disorders of pregnancy are common and form one of the deadly triad, along with hemorrhage and infection, which contribute greatly to maternal and fetal jeopardy. Methods The aim of this study was to assess the prevalence of hypertensive disorders of pregnancy, and determine the effects of hypertensive disorders of pregnancy on the feto-maternal outcomes. It was a descriptive, cross-sectional, retrospective study on 615 women who attended delivery at Yekatit-12 Teaching Hospital from July 2017 - Jan 2018. Data was analyzed using SPSS version 20 software. Descriptive statistics were used to calculate rates. Chi-square statistics were used to estimate the associations among selected predictor variables. A p-value < 0.05 was taken as statistically significant. Results Out of the 615 study population, the prevalence of hypertensive disorders of pregnancy was found to be 25.4%, of which the majority (54.5%) was severe pre-eclampsia. Eclampsia accounted for 2.6%, and superimposed pre-eclampsia was 2.6%. The rate of severe pre-eclampsia with HELLP syndrome was 7.1% of all mothers with the hypertensive disorders. The majority of mothers with hypertensive disorders (59.6%) had age range of 25-34 years. About 46% of mothers required interventions to terminate the pregnancy either by cesarean section (42.3%) or instrumental deliveries (3.7%). The rate of preterm, low birth weight, and low Apgar at 1st and 5thminutes accounted for 30%, 25%, 24.4% and 16.7% of neonates born to mothers with hypertensive disorders, respectively. Over 19% of neonates required resuscitation and 11.5% NICU referral. The rate of still birth was 2.6%. Conclusion The prevalence of hypertensive disorders of pregnancy is high in the study area and complicates maternal and fetal outcomes of the pregnancy. To deter its detrimental effects both on fetal and maternal outcomes of pregnancy, antenatal surveillance should be expanded to enable early detection, stringent follow-up and timely intervention in severely affected pregnancies.
Behavior of a Sandy Silt Reinforced with Discontinuous Recycled Fiber Inclusions

Laboratory compaction and triaxial compression tests were performed to assess the compaction characteristics and load deformation response of a sandy silt reinforced with randomly oriented recycled carpet fibers. Discrete, randomly distributed fiber inclusions significantly increase the peak shear strength, reduce the postpeak strength loss, increase the axial strain to failure, and, in some cases, change the stress-strain behavior from strain softening to strain hardening for a sandy silt. Fiber inclusions also impede the compaction process, causing a reduction in the maximum dry density of reinforced specimens with increasing fiber content. The strength losses associated with in-service saturation are significantly reduced with fiber reinforcement. It is suggested that large volumes of recycled waste fibers can be used as a value-added product to enhance the shear strength and load deformation response of soils.
Active Suspension of Truck Seat

The driver’s seat of a heavy duty truck is usually mounted on a spring–damper assembly anchored to the cab floor. To improve riding comfort, this study investigated the effects of mounting a computer-controlled actuator in parallel with the traditional spring–damper assembly. A dynamic model of the seat is represented by a two degree-of-freedom system, including a cushion. In this paper, a control system is designed, using optimal control theory, which minimizes rms vertical acceleration at a point representing the driver’s hip point. In this system, accelerations of the hip point, the seat frame and the cab floor are picked up and integrated to obtain the state variables to be fed back and fed forward to the actuator through a digital computer. The actuator is constructed with electric servo-motor and ball-screw mechanism. The experimental study was carried out on a shaker, which simulates the vibrations of the cab floor in actual service. Results were obtained for both a dummy and a real human body. The vibration test produced rms accelerations of the seat and the hip point of about 1.0 m/s2 without the actuator, while the rms accelerations were suppressed to about 0.5 m/s2 at a rms input voltage to the servo-motor of 1.0 V.
Ion induced charge collection in GaAs MESFETs

Charge-collection measurements on GaAs MESFET test structures demonstrate that more charge can be collected at the gate than is deposited in the active layer and more charge can be collected at the drain than the total amount of charge produced by the ion. Enhanced charge collection at the gate edge has also been observed. The current transients produced by the energetic ions have been measured directly with about 20-ps resolution. The significance of this work is that it shows charge-collection phenomena in GaAs MESFETs to be very complex with important implications for modeling SEU (single-event upset) phenomena and developing techniques to mitigate SEU effects. >
Ultra-wideband antenna with improved gain characteristics

A ultra-wideband (UWB) antenna with improved gain characteristics is proposed. With the improvements, it is discussed in terms of the band notch and enhanced radiation patterns. Shaping the return loss as an approach in order to achieve these characteristics is introduced and a multi-resonant dipole structure is designed and experimented in frequency and time domains. The proposed UWB antenna provides the band notch with a sharp slope and improved gain deviation on azimuth plane for the UWB communication.