nils-herrmann/clean_scirepeval huggingface dataset:
The capacity optimality of beam steering in large millimeter wave MIMO systems

Millimeter wave (mmWave) systems must overcome the heavy attenuation at high frequency to support high-throughput wireless communication. The small wavelength in mmWave systems enables beamforming using large antenna arrays to combat path loss with large array gain. Beamforming in traditional microwave systems is often done at baseband for maximum flexibility. Such baseband processing requires a dedicated transceiver chain per antenna element. The high cost of radio frequency (RF) chains in mmWave systems, however, makes supporting each antenna with a dedicated RF chain expensive. This mismatch between the number of antennas and transceiver chains makes baseband processing infeasible; thus mmWave systems typically rely on a traditional approach known as beam steering which can be done at RF using inexpensive phase shifters. Unlike baseband precoding, however, traditional beam steering is not explicitly designed to achieve the capacity of the mmWave channel. In this paper, we consider both beamforming and multi-stream precoding in single user systems with large mmWave antenna arrays at both transmitter and receiver. Using a realistic channel model, we show that the unconstrained capacity-achieving precoding solutions converge to simple beam steering solutions. Therefore, in large mmWave systems, no rate loss is incurred by adopting the traditional lower-complexity solution.
A 40-50-GHz SiGe 1 : 8 differential power divider using shielded broadside-coupled striplines

This paper presents a 1 : 8 differential power divider implemented in a commercial SiGe BiCMOS process using fully shielded broadside-coupled striplines integrated vertically in the silicon interconnect stackup. The 1 : 8 power divider is only 1.12 x1.5 mm2 including pads, and shows 0.4-dB rms gain imbalance and <3deg rms phase imbalance from 40 to 50 GHz over all eight channels, a measured power gain of 14.9 plusmn0.6 dB versus a passive divider at 45 GHz, and a 3-dB bandwidth from 37 to 52 GHz. A detailed characterization of the shielded broadside-coupled striplines is presented and agrees well with simulations. These compact lines can be used for a variety of applications in SiGe/CMOS millimeter-wave circuits, including differential signal distribution, miniature power dividers, matching networks, filters, couplers, and baluns.
University Students' Satisfaction with their Academic Studies: Personality and Motivation Matter

Although there is consensus about the importance of students' satisfaction with their academic studies as one facet of academic success, little is known about the determinants of this significant outcome variable. Past research rarely investigated the predictive power of multiple predictors simultaneously. Hence, we examined how demographic variables, personality, cognitive and achievement-related variables (intelligence, academic achievement), as well as various motivational constructs were associated with three different dimensions of satisfaction (satisfaction with study content, satisfaction with the conditions of the academic program, satisfaction with the ability to cope with academic stress) assessed approximately 2 years apart. Analyzing data of a sample of university students (N = 620; M age = 20.77; SD age = 3.22) using structural equation modeling, our results underline the significance of personality and motivational variables: Neuroticism predicted satisfaction with academic studies, but its relevance varied between outcome dimensions. Regarding the predictive validity of motivational variables, the initial motivation for enrolling in a particular major was correlated with two dimensions of subsequent satisfaction with academic studies. In contrast, the predictive value of cognitive and achievement-related variables was relatively low, with academic achievement only related to satisfaction with the conditions of the academic program after controlling for the prior satisfaction level.
6.5 kV Si/SiC hybrid power module: An ideal next step?

Silicon carbide (SiC) power switches such as JFET or MOSFET have demonstrated their superior advantages over silicon (Si) power devices such as IGBT, especially in terms of significantly reduced switching losses. A major issue facing large scale adoption of SiC power devices is still the much higher cost. This paper proposes that Si/SiC hybrid power module (HPM) should be a natural next step moving forward for high voltage applications to address the cost issue. In the proposed Si/SiC HPM, a SiC JFET is connected in parallel with Si IGBT to combine the advantages of both IGBT and JFET. A 6.5 kV HPM is developed based on Si IGBT and SiC JFET as an example to demonstrate its superior cost/performance. The switching loss can be reduced by more than 70% at a cost of about 70% higher compared to Si IGBT. This work is especially essential for high voltage applications such as medium voltage motor drive, FACTS and HVDC systems.
Software Security Requirements Gathering Instrument

Security breaches are largely caused by the vulnerable software. Since individuals and organizations mostly depend on softwares, it is important to produce in secured manner. The first step towards producing secured software is through gathering security requirements. This paper describes Software Security Requirements Gathering Instrument (SSRGI) that helps gather security requirements from the various stakeholders. This will guide the developers to gather security requirements along with the functional requirements and further incorporate security during other phases of software development. We subsequently present case studies that describe the integration of the SSRGI instrument with Software Requirements Specification (SRS) document as specified in standard IEEE 830-1998. Proposed SSRGI will support the software developers in gathering security requirements in detail during requirements gathering phase.
Operating Systems for Low-End Devices in the Internet of Things: A Survey

The Internet of Things (IoT) is projected to soon interconnect tens of billions of new devices, in large part also connected to the Internet. IoT devices include both high-end devices which can use traditional go-to operating systems (OSs) such as Linux, and low-end devices which cannot, due to stringent resource constraints, e.g., very limited memory, computational power, and power supply. However, large-scale IoT software development, deployment, and maintenance requires an appropriate OS to build upon. In this paper, we thus analyze in detail the specific requirements that an OS should satisfy to run on low-end IoT devices, and we survey applicable OSs, focusing on candidates that could become an equivalent of Linux for such devices, i.e., a one-size-fits-most, open source OS for low-end IoT devices.
Biomechanical Design of a Novel Flexible Exoskeleton for Lower Extremities

This paper presents a novel wearable walking assistance device for the elderly to provide physical gait assistance. The wearable device, to be worn invisibly underneath clothes, not only fits tightly to the wearer's lower body, but also comfortably transmits assistive torque to the wearer's hip/knee joint. To overcome deficiencies in the usability of conventional wearable walking assistance devices, two novel features are proposed: 1) a unique flexible support frame that withstands vertical loads while maintaining the natural curvature of the wearer's lower body; and 2) a kinematically similar anthropomorphic joint that minimizes the unintended resistance force during the wearer's usual motions. The developed wearable walking assistance device based on these features was verified by simulations and experiments whose results are described.
Quaternion-Based Unscented Kalman Filter for Accurate Indoor Heading Estimation Using Wearable Multi-Sensor System

Inertial navigation based on micro-electromechanical system (MEMS) inertial measurement units (IMUs) has attracted numerous researchers due to its high reliability and independence. The heading estimation, as one of the most important parts of inertial navigation, has been a research focus in this field. Heading estimation using magnetometers is perturbed by magnetic disturbances, such as indoor concrete structures and electronic equipment. The MEMS gyroscope is also used for heading estimation. However, the accuracy of gyroscope is unreliable with time. In this paper, a wearable multi-sensor system has been designed to obtain the high-accuracy indoor heading estimation, according to a quaternion-based unscented Kalman filter (UKF) algorithm. The proposed multi-sensor system including one three-axis accelerometer, three single-axis gyroscopes, one three-axis magnetometer and one microprocessor minimizes the size and cost. The wearable multi-sensor system was fixed on waist of pedestrian and the quadrotor unmanned aerial vehicle (UAV) for heading estimation experiments in our college building. The results show that the mean heading estimation errors are less 10° and 5° to multi-sensor system fixed on waist of pedestrian and the quadrotor UAV, respectively, compared to the reference path.
Effect of Selected Thiols on Cross-Linking of Acrylated Epoxidized Soybean Oil and Properties of Resulting Polymers

The effect of the chemical structure and functionality of three structurally different thiols on the cross-linking of acrylated epoxidized soybean oil and on the properties of the resulting polymers was investigated in this study. 1,3-Benzenedithiol, pentaerythritol tetra(3-mercaptopropionate), and an hexathiol synthesized from squalene were used in the cross-linking of acrylated epoxidized soybean oil by thiol–Michael addition reaction. The reactivity of thiols determined from calorimetric curves followed the order: 1,3-benzenedithiol > pentaerythritol tetra(3-mercaptopropionate) > hexathiolated squalene. Thermal and mechanical properties and the swelling in different solvents of the cross-linked polymers were studied. The cross-linked polymer obtained from 1,3-benzenedithiol showed the highest swelling values in chloroform and toluene. The cross-linked polymer with pentaerythritol tetra(3-mercaptopropionate) fragments showed the best mechanical performance (highest mechanical strength and Young’s modulus) and thermal stability. The cross-linked polymers from hexathiolated squalene showed the highest glass transition temperature.
Mobility management enhancements for 5G low latency services

The 5G vision is to create a network that outperforms the current mobile networks in terms of flexibility, performance and use cases. This raises the requirements of the network to a totally new level. In order to achieve the latency goals the related applications and network functions need to be placed into the network edge. Full mobility support requires also enhancements to the current mobility management procedures. These include a gateway selection algorithm that is topology aware, handover procedures that are able to switch the user plane as quickly as possible and a seamless gateway relocation procedure. The low latency applications should also be able to manage the state between the application instances in different edge nodes. In this paper we introduce a 5G low latency network slice that offers 5G low latency services from the closest network edge node. Our prototype implementation verifies that this can be achieved by re-evaluating the optimality of the mobility anchor during each handover and executing a gateway relocation procedure when needed.
Development of a brief ataxia rating scale (BARS) based on a modified form of the ICARS.

To develop a brief ataxia rating scale (BARS) for use by movement disorder specialists and general neurologists. Current ataxia rating scales are cumbersome and not designed for clinical practice. We first modified the International Cooperative Ataxia Rating Scale (ICARS) by adding seven ataxia tests (modified ICARS, or MICARS), and observed only minimally increased scores. We then used the statistics package R to find a five-test subset in MICARS that would correlate best with the total MICARS score. This was accomplished first without constraints and then with the clinical constraint requiring one test each of Gait, Kinetic Function-Arm, Kinetic Function-Leg, Speech, and Eye Movements. We validated these clinical constraints by factor analysis. We then validated the results in a second cohort of patients; evaluated inter-rater reliability in a third cohort; and used the same data set to compare BARS with the Scale for the Assessment and Rating of Ataxia (SARA). Correlation of ICARS with the seven additional tests that when added to ICARS form MICARS was 0.88. There were 31,481 five-test subtests (48% of possible combinations) that had a correlation with total MICARS score of > or =0.90. The strongest correlation of an unconstrained five-test subset was 0.963. The clinically constrained subtest validated by factor analysis, BARS, had a correlation with MICARS-minus-BARS of 0.952. Cronbach alpha for BARS and SARA was 0.90 and 0.92 respectively; and inter-rater reliability (intraclass correlation coefficient) was 0.91 and 0.93 respectively. BARS is valid, reliable, and sufficiently fast and accurate for clinical purposes.
Yoga for anxiety: a systematic review of the research evidence.

Between March and June 2004, a systematic review was carried out of the research evidence on the effectiveness of yoga for the treatment of anxiety and anxiety disorders. Eight studies were reviewed. They reported positive results, although there were many methodological inadequacies. Owing to the diversity of conditions treated and poor quality of most of the studies, it is not possible to say that yoga is effective in treating anxiety or anxiety disorders in general. However, there are encouraging results, particularly with obsessive compulsive disorder. Further well conducted research is necessary which may be most productive if focused on specific anxiety disorders.
Multipurpose autonomous agricultural robot

More than 40 percent of the population in the world chooses agriculture as the primary occupation. In recent years, increased interest has grown for the development of the autonomous vehicles like robots in the agriculture. The existing agricultural robot performs basic elementary functions like harvesting, planting and spreading the pesticides. The Proposed system aims at designing multipurpose autonomous agricultural robotic vehicle which can be controlled through Bluetooth for ploughing, seeding and irrigation systems. This is especially important for the workers in the area of potentially harmful for the safety and health of the workers. These robots are used to reduce human intervention, ensuring proper irrigation and efficient utilization of resources. These robots are mainly useful in automated weed control; usage of fertilizers based on soil condition, soil sensors for drip irrigation in rain feed areas.
Prediction of click frauds in mobile advertising

Click fraud represents a serious drain on advertising budgets and can seriously harm the viability of the internet advertising market. This paper proposes a novel framework for prediction of click fraud in mobile advertising which consists of feature selection using Recursive Feature Elimination (RFE) and classification through Hellinger Distance Decision Tree (HDDT).RFE is chosen for the feature selection as it has given better results as compared to wrapper approach when evaluated using different classifiers. HDDT is also selected as classifier to deal with class imbalance issue present in the data set. The efficiency of proposed framework is investigated on the data set provided by Buzzcity and compared with J48, Rep Tree, logitboost, and random forest. Results show that accuracy achieved by proposed framework is 64.07 % which is best as compared to existing methods under study.
Gigantomastia in pregnancy with an accessory axillary mass masquerading as inflammatory carcinoma.

Giagantomastia is a rare disorder known to occur in pregnancy, causing enlargement of the breasts greater than that of gravid enlargement. The histological features of gigantomastia are glandular hyperplasia and an increase of stromal tissue. Illustrated by one documented case, cytomorphology of gigantomastia was misdiagnosed as a phyllodes tumor. We document the cytomorphology of an axillary mass in a gravid woman of 24 years with gigantomastia. She presented in her first trimester with bilateral mastalgia and swelling, nonresponsive to antibiotics. Imaging excluded mass breast lesions and a pituitary prolactinoma. The breasts progressively enlarged, became warm, tender, and developed skin ulcerations and a peau d'orange appearance. Subsequently she developed a mass in her left axilla. On aspiration of the mass, some of the cytomorphological features were suspicious for a metastasis, which correlated well with her clinical features. Careful evaluation suggested cytomorphology to be compatible with benign accessory breast tissue with possible hormone related changes of pregnancy. Histology of the excised axillary mass confirmed this diagnosis. Thus, awareness of this rare condition and careful evaluation is mandatory to avoid misdiagnosis in a similar clinical context.
Detection , localization and characterization of damage in plates with an in situ array of spatially distributed ultrasonic sensors

Permanently attached piezoelectric sensors arranged in a spatially distributed array are under consideration for structural health monitoring systems incorporating active ultrasonic methods. Most damage detection and localization methods that have been proposed are based upon comparing monitored signals to baselines recorded from the structure prior to initiation of damage. To be effective, this comparison process must take into account any conditions other than damage that have changed the ultrasonic signals. Proposed here is a two-step process whereby damage is first detected and is then localized and characterized. The detection strategy considers the long time behavior of the signals in the diffuse-like regime where distinct echoes can no longer be identified. The localization strategy is to generate images of damage based upon the early time regime when discrete echoes from boundary reflections and scattering sites are meaningful. Results are shown for an aluminum plate with artificial damage introduced in combination with temperature variations. The loss of local temporal coherence combined with an optimal baseline selection procedure is shown to be effective for the detection of damage, and a delay-and-sum imaging method applied to the residual signals both localizes the damage and provides characterization information. (Some figures in this article are in colour only in the electronic version)
Evaluation of Cluster Identification Performance for Different PCP Variants

Parallel coordinate plots (PCPs) are a well-known visualization technique for viewing multivariate data. In the past, various visual modifications to PCPs have been proposed to facilitate tasks such as correlation and cluster identification, to reduce visual clutter, and to increase their information throughput. Most modifications pertain to the use of color and opacity, smooth curves, or the use of animation. Although many of these seem valid improvements, only few user studies have been performed to investigate this, especially with respect to cluster identification. We performed a user study to evaluate cluster identification performance – with respect to response time and correctness – of nine PCP variations, including standard PCPs. To generate the variations, we focused on covering existing techniques as well as possible while keeping testing feasible. This was done by adapting and merging techniques, which led to the following novel variations. The first is an effective way of embedding scatter plots into PCPs. The second is a technique for highlighting fuzzy clusters based on neighborhood density. The third is a spline-based drawing technique to reduce ambiguity. The last is a pair of animation schemes for PCP rotation. We present an overview of the tested PCP variations and the results of our study. The most important result is that a fair number of the seemingly valid improvements, with the exception of scatter plots embedded into PCPs, do not result in significant performance gains.
Imbalance in the cloud: An analysis on Alibaba cluster trace

To improve resource efficiency and design intelligent scheduler for clouds, it is necessary to understand the workload characteristics and machine utilization in large-scale cloud data centers. In this paper, we perform a deep analysis on a newly released trace dataset by Alibaba in September 2017, consists of detail statistics of 11089 online service jobs and 12951 batch jobs co-locating on 1300 machines over 12 hours. To the best of our knowledge, this is one of the first work to analyze the Alibaba public trace. Our analysis reveals several important insights about different types of imbalance in the Alibaba cloud. Such imbalances exacerbate the complexity and challenge of cloud resource management, which might incur severe wastes of resources and low cluster utilization. 1) Spatial Imbalance: heterogeneous resource utilization across machines and workloads. 2) Temporal Imbalance: greatly time-varying resource usages per workload and machine. 3) Imbalanced proportion of multi-dimensional resources (CPU and memory) utilization per workload. 4) Imbalanced resource demands and runtime statistics (duration and task number) between online service and offline batch jobs. We argue accommodating such imbalances during resource allocation is critical to improve cluster efficiency, and will motivate the emergence of new resource managers and schedulers.
Design, Modeling, and Control of an Aerial Robot DRAGON: A Dual-Rotor-Embedded Multilink Robot With the Ability of Multi-Degree-of-Freedom Aerial Transformation

In this letter, we introduce a novel transformable aerial robot called DRAGON, which is a dual-rotor-embedded multilink robot with the ability of multi-degree-of-freedom (DoF) aerial transformation. The new aerial robot can control the full pose in $\mathsf {SE}(3)$ regarding the center of gravity (CoG) of multilinks and can render the multi-DoF aerial transformation, which is accomplished by the original two-DoF force vectoring mechanism on each link called the dual-rotor gimbal module. The dynamics is derived on the basis of the special definition of CoG orientation, followed by a control method decoupled into thrust force control and rotor gimbal control. In the thrust force control, the minimum force norm is considered to avoid force saturation, and the rotor gimbal control method is developed to enhance both translational and rotational stabilities during hovering and large-scale aerial transformation. The prototype composed of four links is constructed, and associated preliminary experiments are performed. The feasibility of the novel mechanical design and the proposed control method for the aerial transformation is demonstrated.
Reconstructing the Shape of a Deformable Membrane from Image Data

In this paper, we study the problem of determining a mathematical description of the surface defined by the shape of a membrane based on an image of it and present an algorithm for reconstructing the surface when the membrane is deformed by unknown external elements. The given data are the projection on an image plane of markings on the surface of the membrane, the undeformed configuration of the membrane, and a model for the membrane mechanics. The method of reconstruction is based on the principle that the shape assumed by the membrane will minimize the elastic energy stored in the membrane subject to the constraints implied by the measurements. Energy minimization leads to a set of nonlinear partial differential equations. An approximate solution is found using linearization. The initial motivation, and our first application of these ideas, comes from tactile sensing. Experimental results affirm that this approach can be very effective in this context. membrane mechanics, soft fingers, imaging shape