Miracle-dz/UniFAR-FTUs huggingface dataset:
Stability of water-lubricated, hydrostatic, conical bearings with spiral grooves for high-speed spindles

In this paper, the stability of water-lubricated, hydrostatic, conical bearings with spiral grooves for high-speed spindles is investigated theoretically and experimentally. In these bearing types, pressurized water is first fed to the inside of the rotating shaft and then introduced into spiral grooves through feeding holes located at one end of each spiral groove. Therefore, water pressure is increased due to the effect of the centrifugal force at the outlets of the feeding holes, which results from shaft rotation. In addition, water pressure is also increased by the viscous pumping effect of the spiral grooves. The stability of the proposed bearing is theoretically predicted using the perturbation method, and calculated results are compared with experimental results. It was consequently found that the proposed bearing is very stable at high speeds and theoretical predictions show good agreement with experimental data.
Dynamic performance of packed-bed dehumidifiers: experimental results from the SERI desiccant test loop

Discussed are the design and construction of a desiccant test loop and results of tests with a silica-gel-packed bed. The test loop consists of two centrifugal fans, two duct heaters, a steam humidifier, 24.4m (80 ft) of 30-cm (12-in.) circular duct, instrumentation, and a test section. The loop is capable of testing adsorption and desorption modes at flow rates up to 0.340 kg/s (600 scfm) and at regeneration temperatures up to 120/sup 0/C (248/sup 0/F). Tests of a 74-cm(29-in.)-diameter, 3.2-cm(1.25-in.)-thick silica gel bed indicated that mass transfer occurs more readily in the adsorption direction than in the desorption direction. Pressure drop data indicated that the resistance of each of the two screens that hold the silica gel in place was equivalent to 2.5-cm(1-in.) of silica gel due to plugging. Results of the tests were also used to validate a SERI desiccant computer model, DESSIM.
Pretest and shrinkage estimation strategies in accelerated failure time model

This paper focuses on the accelerated failure time model which is often suggested as an alternative to the Cox proportional hazards model. We propose pretest and shrinkage estimation methods for estimating the regression parameters in the accelerated failure time model for right-censored data when some of the parameters shrink to a restricted subspace. Shrinkage estimators take information from the unrestricted model and provide an efficient estimate of the regression parameters by shrinking the unrestricted estimate toward the restricted model estimate. This technique increases the bias in the estimation process but reduces the overall mean-squared error, which offsets the bias. We show that if the shrinkage dimension exceeds two, the risk of the shrinkage estimator is strictly less than that of the maximum-likelihood estimator. Extensive numerical studies are conducted to evaluate the performance of the pretest and shrinkage estimators. An empirical application is provided to illustrate the practical usefulness of the proposed estimators.
A simulation testing and analysis of aggregate production planning strategies

In this study, a hybrid discrete event simulation (DES) and system dynamics (SD) methodology is applied to model and simulate aggregate production planning (APP) problem for the first time. DES is used to simulate operational-level and shop-floor activities incorporated into APP and estimate critical time-based control parameters used in SD model of APP and SD is used to simulate APP as a collection of aggregate-level strategic decisions. The main objective of this study is to determine and analyse the effectiveness of APP strategies regarding the Total Profit criterion by developing a hybrid DES–SD simulation model for APP in a real-world manufacturing company. The simulation results demonstrated that the priority of APP strategies with regards to Total Profit criterion is: (1) the pure chase strategy, (2) the modified chase strategy, (3) the pure level strategy, (4) the modified level strategy, (5) the mixed strategy and (6) the demand management strategy, respectively. The APP system is first simulated under mixed strategy (basic scenario) conditions to include all APP capacity and demand options in constructed SD simulation model to show a comprehensive view of APP components and their interdependent interactions. Then, the obtained results will be used as Total Profit measure to compare with system's performance under some experimental scenarios applying different APP strategies.
A feature-based affine registration method for capturing background lung tissue deformation for ground glass nodule tracking

ABSTRACT Apparent changes in lung nodule size assessed via simple image-based measurements from computed tomography (CT) images may be compromised by the effect of the background lung tissue deformation on the nodule, leading to erroneous nodule tracking. We propose a feature-based affine registration method and study its performance vis-a-vis several other registration methods. We implement and test each registration method using a lung- and a lesion-centred region of interest on 10 patient CT datasets featuring 12 nodules. We evaluate each registration method according to the target registration error (TRE) computed across 30–50 homologous fiducial landmarks selected by expert radiologists. Our results show that the proposed feature-based affine lesion-centred registration yielded a 1.11. 2 mm TRE, while a Symmetric Normalisation deformable registration yielded a 1.21. 2 mm TRE, with a baseline least-square fit of the validation fiducial landmarks of 1.51. 2 mm TRE. The proposed feature-based affine registration is computationally efficient, eliminates the need for nodule segmentation, and reduces the susceptibility of artificial deformations. We also conducted a pilot pre-clinical study that showed the proposed feature-based lesion-centred affine registration effectively compensates for the background lung tissue deformation and serves as a reliable baseline registration method prior to assessing lung nodule changes due to disease.
Thermally switched superconducting weak-link transistor with current gain

We report on a method of controling the critical current in a superconducting weak-link device. A superconducting weak-link transistor with an integrated, but electrically isolated, heater has been fabricated. The heater raises the temperature of the weak link above the bath temperature thus reducing the critical current required to give an output voltage. A maximum current gain (ratio of critical current change to applied heater current change) of 10.5 was achieved.
Accelerated Stiffness Profiling of Aggregate Bases and Subgrades for Quality Assessment of Field Compaction

As a compaction control parameter, stiffness has been investigated as an alternative to dry unit weight, because the design of pavement is based on the elastic modulus of pavement layers. A reliable and practical quality assurance system was proposed to accelerate the quality assessment of field compaction. The proposed system, which has evolved from the spectral analysis of surface waves (SASW) method, profiles the shear wave velocity of the unbound aggregate base and subgrade. The system consists of dedicated hardware for surface wave measurements and an analysis algorithm to automate the interpretation and analysis procedures. The measurement hardware consists of two sensor units and one source unit and can be operated by one person. The automation in interpretation and analysis was implemented with the peak–trough method and the frequency wave number technique. Consequently, the surface wave measurement for stiffness profiling is reduced to a 10- to 15-min task. The validity of the proposed hardware and algorithm was verified by a comparison of the results acquired by the conventional SASW measurements with the results acquired by the accelerated SASW system. Twenty-one subgrade and 11 base sections were selected at three pavement construction sites and tested with the accelerated SASW system, the dynamic cone penetrometer (DCP), the plate-bearing test, and the falling weight deflectometer (FWD). Results indicated that the shear wave velocity predicted by the accelerated SASW system showed a favorable agreement with DCP index at both subgrades and bases. Young's modulus evaluated from the shear wave velocity also agreed roughly with the FWD modulus and subgrade reaction coefficients.
An Assessment on Geographically Weighted Regression-Based Merging Method of Satellite and Gauge Rainfall

Satellite-derived and gauge rainfall data are incompatible spatial data. Although great efforts have been devoted to their combination recently, it is still a complicated issue to be addressed. In this study, the performance of merging satellite and gauge rainfall analyses is examined over a humid region in Southeast China. Using satellite rainfall from TRMM 3B43V7 and ground rain gauge measurements, a geographically weighted regression (GWR) based statistical merging algorithm was proposed to continuously produce monthly rainfall fields at 1-km resolution during the period 2003-2009. Results indicate that the benefits of this rainfall merging approach were remarkable only when the gauge density is lower than one gauge per 1,500 km2, suggesting the information provided by TRMM 3B43V7 is more useful for estimating rainfall fields when the ground measurements are rather sparse.
Perceptions of Precast Concrete Cladding in the UK Market

Abstract Precast concrete cladding accounts for about 5% of the UK cladding market, despite its performance and aesthetic advantages over competitor materials. A study of perceptions of precast concrete cladding (PCC) was undertaken with the aim of assessing awareness and use of PCC in the UK in its most popular applications (i.e. commercial and residential buildings), in addition to identifying possible directions for future research and development. Interviews were undertaken with participants who were familiar with PCC (predominantly on commercial buildings) and who had had experience of stone-faced, reconstituted stone, cast stone and brickfaced precast cladding. The interviewees identified major opportunities/impelling factors thought to encourage the use of PCC and major barriers/impeding factors thought to discourage its use. A simple scoring system was used to combine the number of responses for each factor with the relative importance assigned to each response. ‘Buildability’, ‘quality’ and ‘speed of erection’ were the most highly rated impelling factors whereas ‘lead time’, ‘initial cost’ and ‘logistics and cranage’ were the most highly rated impeding factors. Developments in production techniques, finishes and sustainability performance together with the need for improved marketing of the product were identified by interviewees as key activities to improve PCC's share of the UK cladding market.
Symmetry and Symmetry Breaking in Physics: From Geometry to Topology

Symmetry (and group theory) is a fundamental principle of theoretical physics. Finite symmetries, continuous symmetries of compact groups, and infinite-dimensional representations of noncompact Lie groups are at the core of solid physics, particle physics, and quantum physics, respectively. The latter groups now play an important role in many branches of mathematics. In more recent years, we have been faced with the impact of topological quantum field theory (TQFT). Topology and symmetry have deep connections, but topology is inherently broader and more complex. While the presence of symmetry in physical phenomena imposes strong constraints, topology seems to be related to low-energy states and is very likely to provide information about the different dynamical trajectories and patterns that particles can follow. For example, regarding the relationship of topology to low-energy states, Hodge’s theory of harmonic forms shows that the zero-energy states (for differential forms) correspond to the cohomology. Regarding the relationship of topology to particle trajectories, a topological knot can be seen as an orbit with complex properties in spacetime. The various deformations or embeddings of the knot, performed in low or high dimensions, allow defining different equivalence classes or topological types, and interestingly, it is possible from these types to study the symmetries associated with the deformations and their changes. More specifically, in the present work, we address two issues: first, that quantum geometry deforms classical geometry, and that this topological deformation may produce physical effects that are specific to the quantum physics scale; and second, that mirror symmetry and the phenomenon of topological change are closely related. This paper was aimed at understanding the conceptual and physical significance of this connection.
Bus Supervision Deployment Strategies and Use of Real-Time Automatic Vehicle Location for Improved Bus Service Reliability

Bus service reliability has long been a top concern for transit agencies and their customers. Improving service reliability, however, has not been easy to accomplish. The use of appropriate recovery times, improved operator training, and better street supervision has produced limited results. Supervision deployment strategies and the use of real-time automatic vehicle location (AVL) information are investigated to improve current supervision practices and enhance bus service reliability. The Chicago (Illinois) Transit Authority's real-time AVL pilot project for Route 20 Madison is the case study for evaluation of the effectiveness of real-time AVL to improve reliability. A simulation model of the route was developed on the basis of archived AVL data and was used to predict the effects on service reliability when real-time AVL information is used in bus supervision. A week-long experiment was carried out both to verify the model and to address the feasibility and scalability of the system. The main conclusion is that real-time AVL does indeed have great potential to improve service reliability. Service restoration strategies previously impossible to execute are now feasible because of this new information stream. However, many obstacles remain to networkwide implementation, including the supervision communications structure and manpower deployment questions. The flood of information into a central control center must also be addressed. Automation techniques and exception-based reporting are strategies to deal with the problem of information overload.
Model Driven Engineering for Distributed Real-Time Embedded Systems

Model-based development methods, and supporting technologies, can provide the techniques and tools needed to address the dilemma between reducing system development costs and time, and developing increasingly complex systems. This book provides the information needed to understand and apply model-drive engineering (MDE) and model-drive architecture (MDA) approaches to the development of embedded systems. Chapters, written by experts from academia and industry, cover topics relating to MDE practices and methods, as well as emerging MDE technologies. Much of the writing is based on the presentations given at the Summer School MDE for Embedded Systems held at Brest, France, in September 2004.
Knowledge brokerage needs in building care robotics innovation ecosystems and networks

ABSTRACT In the ecosystem and network perspectives on innovation, cooperation between various actors is seen as essential to innovation. Because of several factors known to hinder cooperation, the literature has pointed out the need for knowledge brokerage functions. This paper investigates knowledge brokerage needs in building care robotics innovation ecosystems and networks in Finland. The research questions are as follows: What are macro-, meso- and micro-level brokerage needs, functions and roles in care robotics innovation ecosystems and networks, and what kinds of knowledge should be brokered at these different levels? The data were collected with multilevel interviews, including interviewees representing different interests and fields of expertise. Based on the results, there is a need for brokerage functions in emerging ecosystems and networks to create operational conditions, bring disparate actors together, manage innovation processes, create learning possibilities and share best practices. However, the brokerage needs to vary by level, indicating that the functions and roles of the brokers and brokered knowledge may be emphasized differently. At the macro level, system-level knowledge is needed, at the meso level, knowledge related to innovation process management and user knowledge is needed, and at the micro level, the need for experimental and tacit knowledge is highlighted.
Cost–benefit analysis for optimal distributed generation placement in distribution systems

This paper presents an optimisation method to determine optimal allocations of distributed generation (DGs) and capacitors based on maximisation of a profit/worth analysis approach. The optimal locations and sizes of DGs and capacitors have been determined by minimising the power distribution loss. This method considers various technical and economic factors such as line losses, sizes of DGs and capacitors at optimal locations, investment costs, operating costs and maintenance costs of DG and capacitor to achieve the objective for a predetermined number. The electricity market price of grid power has been considered to recover initial investment in a specified time period. The improvement in the voltage profile of the system has also been considered in this work. The particle swarm optimisation technique has been used to solve the optimal placement of DGs and capacitors to maximise the profit. The proposed technique is tested on 33-bus and 69-bus test systems.
Statistical and Practical Significance of Articles at Sports Biomechanics Conferences

Background. The importance of using statistical approaches has increased and became necessary for researchers and specialists in sports biomechanics because they need more objective and accurate methods to increase knowledge. Objectives. Evaluate the reality of using practical significance in the articles published in scientific conferences in the biomechanical sport. Methods. One hundred twenty-four articles were analyzed of 134 in terms of statistical approaches to calculate practical significance. These results were then compared with those of statistical significance to reveal the extent of similarities or differences between the results. Results. The mean test, which was the most commonly used descriptive statistical test, was applied in 114 articles (i.e., 92%); the T-test of paired samples, which was the most used difference measurement tests, was involved in 45 papers (i.e., 36%), statistical tests that measure the relationship between variables were used in 46 articles (i.e., 37%). Likewise, no items used advanced statistical tests except for six articles (i.e., 5%), which used regression and factor analysis. T-test independent samples are the most used statistical tests in sports biomechanics articles in which the results of practical significance matched those of statistical significance (88%). Conclusion. The use of practical significance was almost non-existent. Also, it was observed that there was a large percentage of practical significance mismatch with the statistical significance of many statistical tests, which was a considerable negative indicator that affected the quality of sports biomechanics articles.
Analysis of a database of subsidence damage

Describes the format and scope of a database of predominantly technical information relating to subsidence and heave claims on shrinkable/expansible clay soils. The database includes information on 484 individual subsidence claims, comprising details of the property and its structure, the damage, ground and foundation conditions, vegetation, and monitoring and remedial measures. The data are analysed and implications for the investigation of subsidence claims are examined. The analyses indicate that, among other results: detached properties have greater susceptibility to subsidence or heave claims than non‐detached properties; properties built prior to 1900 are less susceptible to damage than those built in the 1900‐1944 period; there are no reasons to be concerned over current minimum depth requirements for construction in shrinkable/expansible clays; and London clay is the most commonly encountered “problem” soil.
The shortlist effect: nestedness contributions as a tool to explain cultural success

Abstract Abstract Detecting the forces behind the success or failure of cultural products, such as books or films, remains a challenge. Three such forces are drift, context-biased selection and selection based on content – when things succeed because of their intrinsic appeal. We propose a tool to study content-biased selection in sets of cultural collections – e.g. libraries or movie collections – based on the ‘shortlist effect’: the fact that smaller collections are more selective and more likely to favour highly appealing items over others. We use a model to show that, when the shortlist effect is at work, content-biased cultural selection is associated with greater nestedness in sets of collections. Having established empirically the existence of the shortlist effect, and of content-biased selection, in 28 sets of movie collections, we show that nestedness contributions can be used to estimate to what extent specific movies owe their success to their intrinsic properties. This method can be used in a wide range of datasets to detect the items that owe their success to their intrinsic appeal, as opposed to ‘hidden gems’ or ‘accidental hits’.
Precise position control using a PMSM with a disturbance observer containing a system parameter compensator

A deadbeat load torque observer with a system parameter compensator that can be used to improve the performance of a permanent-magnet synchronous motor in a precision position control system is presented. The compensator makes real systems work as it in a nominal parameter system. Therefore, the observer has a performance level equivalent to that obtained if there is no parameter variation. Noise effects are reduced by the use of past-filter implimented using a moving-average process. A comparison study on the system response for a convertional deadbeat gain observer and the proposed parameter-compensated deadbeat observer is performed. The proposed system can be used to cancel out any steady-state or transient position errors created by external disturbances such as friction, load torque or chattering effects.