Your Preference or Mine? A Randomized Field Experiment on Recommender Systems in Two-sided Matching Markets

The literature on recommender systems mainly focuses on product recommendation where buyer’s preferences are considered. However, for user recommendation in two-sided matching markets, potential matches’ preferences may also play a role in focal user’s decision-making. Hence, we seek to understand the impact of providing potential candidates’ preference in such settings. In collaboration with an online dating platform, we design and conduct a randomized field experiment and present users with recommendations based on i) their own preferences, ii) potential matches’ preferences, or iii) mutual preferences. Interestingly, we find that users are sensitive to the provision of potential candidates’ preferences, and they proactively reach out to those “who might prefer them” despite those candidates’ relatively lower desirability. This leads to a greater improvement in matching. The findings provide valuable insights on how to design user recommendation systems beyond the current practice of recommendations based on focal user’s preferences

Analysis of Strength Characteristics and Energy Dissipation of Improved-Subgrade Soil of High-Speed Railway above Mined-Out Areas

To reveal the effect of sand content on the mechanical performance and energy dissipation of cement improved subgrade soil, using universal testing machine and SHPB test device, unconfined compressive strength (UCS) and impact compression strength under different impact load (0.2, 0.3, 0.4, and 0.5 MPa) were carried out for the cement improved subgrade soil with different sand content (0%, 5%, 10%, 15%, and 20%). Results show that the dynamic and static stress-strain curves of the cement improved soil have similar variation trend. With the increase of the sand content, the UCS and impact compressive strength of the cement improved soil both increase first, then decrease later, showing the form of a quadratic function. The strength growth rate and the dynamic increase factor (DIF) reach the maximum values when the sand content is 10%, which is 64.7% and 18.6% larger than that of ordinary improved subgrade soil, respectively. In addition, when the sand content increases from 0% to 20%, the specific dissipation energy increases first, and decreases later. Mixing 10% natural sand is the optimal proportion to obtain better energy dissipation capacity of the sand-cement-improved soil

The numerical prediction of the Earth’s polar motion based on an advanced multivariate algorithm

Since there are complicated changes in the polar motion (PM) from sub-annual to decadal, precisely predicting it is challenging. Here, we provide an advanced multivariate algorithm by combining an iterative oblique singular spectrum analysis (IOSSA) with pseudo data (IOSSApd) and consider more periodic and quasi-periodic signals, especially long-period oscillations (Ding et al., Geophys. Res. Lett., 2019, 46, 13765–13774) and multi-frequency Chandler wobble (Pan, International Journal of Geosciences, 2012, 3, 930–951), than previous studies. The IOSSA in oblique coordinates, due to its weak separability conditions, has a better separation performance than general singular spectrum analysis (SSA), and the IOSSApd approach further solved the shift problem. Upon using the IOSSApd method, the PM data can be separated into deterministic and stochastic components, extrapolated by the multiple-harmonic (MH) and autoregressive integrated moving average (ARIMA) models, respectively. Based on the IERS EOPC04 PM series, we produced multiple sets of PM predictions with a 1-year leading time and reported the IERS Bulletin A predictions as a comparison. For 90-day leading time predictions, the mean absolute errors (MAEs) of the x- and y-components were 7.69 and 5.12 mas, respectively, while the corresponding MAEs obtained by IERS Bulletin A were 9.45 and 5.69 mas, respectively. For up to 360 days, our algorithm obtains the MAEs of PM slowly accumulating to 12.98 mas on average, far better than the 19.14 mas for Bulletin A’s predictions (also significantly superior to the corresponding results given by previous studies). The prediction performance in the middle- and long-term prediction is further compared against the general SSA predictor. By virtue of weak periodic error, our results show that combining the IOSSApd + MH + ARIMA models improved the prediction success rate up to 75.39% and 69.58% for the x- and y-component, respectively

How Do Price and Quantity Promotions Affect Hedonic Purchases? An ERPs Study

Due to consuming hedonic products unnecessary to basic well-being, consumers need justifications for pleasure. However, different justifications have differential influences in promoting hedonic purchases, such as price and quantity promotions (PP and QP), the difference being that the latter requires purchasing additional units to get the same discount as the former. In the present study, even-related potentials (ERPs) was applied to reveal the timing of brain activities to further understand how promotion information consisting of promotion type (PP and QP) and discount depth, deep and shallow discounts (DD and SD) on hedonic products was processed. Behaviorally, consumers were more willing to purchase items in PP and DD conditions than QP and SD conditions, respectively, and spent more time making final purchase decisions in QP and DD condition or PP and SD condition compared to PP and DD condition. Neurophysiologically, DD automatically recruited more attentional resources than SD and led to a higher P2 amplitude. QP and DD condition or PP and SD condition evoked a larger N2 amplitude and enhanced perceptual conflict compared to PP and DD condition. During late stage, PP and DD elicited a more positive LPP amplitude in contrast to QP and SD, respectively, indicating that people have stronger purchase intention and positive affect in PP and DD contexts. These findings provided evidence for the differential influences between PP and QP and what ultimately made consumers buy hedonic products or not

Automated turnkey microcomb for low-noise microwave synthesis

Microresonator-based optical frequency comb (microcomb) has the potential to revolutionize the accuracy of frequency synthesizer in radar and communication applications. However, fundamental limit exists for low noise microcomb generation, especially in low size, weight, power and cost (SWaP-C) package. Here we resolve this limit, by the demonstration of an automated turnkey microcomb, operating close to its low quantum-limited phase noise, within a compact setup size of 85 mm * 90 mm * 25 mm. High quality factor fiber Fabry-Perot resonator (FFPR), with Q up to 4.0 * 10^9, is the key for both low quantum noise and pump noise limit, in the diode-pump case in a self-injection locking scheme. Low phase noise of -80 and -105 dBc/Hz at 100 Hz, -106 and -125 dBc/Hz at 1 kHz, -133 and -148 dBc/Hz at 10 kHz is achieved at 10.1 GHz and 1.7 GHz repetition frequencies, respectively. With the simultaneous automated turnkey, low-noise and direct-diode-pump capability, our microcomb is ready to be used as a low-noise frequency synthesizer with low SWaP-C and thus field deployability

Entropy as a Gene‐Like Performance Indicator Promoting Thermoelectric Materials

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138909/1/adma201702712.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138909/2/adma201702712-sup-0001-S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138909/3/adma201702712_am.pd

Structural analysis and insertion study reveal the ideal sites for surface displaying foreign peptides on a betanodavirus-like particle

Additional file 3: The averaged density distribution of the 3D reconstructions. The mass densities of the RBS are spherically averaged and plotted as a function of the particle radius. Below a radius of 115 Å is the density of enclosed RNA fragments (The RNA fragments do not belong to the virus genome, they are arbitrarily enclosed bacterial RNA). The density distribution between 115–150 Å and 150–190 Å are the capsid and the protrusion respectively. In the capsid shell, each subunit arranged in a “jerry-roll” structure results in that the capsid shell looks like two layers (two density peaks)

Effect of Temperature on Electromagnetic Performance of Active Phased Array Antenna

Active phased array antennas (APAAs) can suffer from the effects of harsh thermal environments, which are caused by the large quantity of power generated by densely packed T/R modules and external thermal impacts. The situation may be worse in the case of limited room and severe thermal loads, due to heat radiation and a low temperature sink. The temperature field of the antenna can be changed. Since large numbers of temperature-sensitive electronic components exist in T/R modules, excitation current output can be significantly affected and the electromagnetic performance of APAAs can be seriously degraded. However, due to a lack of quantitative analysis, it is difficult to directly estimate the effect of temperature on the electromagnetic performance of APAAs. Therefore, this study investigated the electromagnetic performance of APAAs as affected by two key factors—the uniformly distributed temperature field and the temperature gradient field—based on different antenna shapes and sizes, to provide theoretical guidance for their thermal design

Escape-zone-based optimal evasion guidance against multiple orbital pursuers

The orbital evasion problem is getting increasing attention because of the increase of space maneuvering objects. In this paper, an escape-zone-based optimal orbital evasion guidance law for an evading spacecraft on near circular reference orbit is proposed against multiple pursuing spacecraft with impulsive thrust. The relative reachable domain is introduced first and approximated as an ellipsoid propagating along the nominal trajectory under the short-term assumption. The escape zone for the impulsive evasion problem is presented herein as a geometric description of the set of terminal positions for all the impulsive evasion trajectories that are not threatened by the maneuvers of pursuers at the maneuver moment. A general method is developed next to calculate the defined escape zone through finding the intersection of two relative reachable domain approximate ellipsoids at arbitrary intersection moment. Then, the two-sided optimal strategies for the orbital evasion problem are analyzed according to whether the escape zone exists, based on which the escape value is defined and used as the basis of the proposed orbital evasion guidance scheme. Finally, numerical examples demonstrate the usefulness of the presented method for calculating escape zone and the effectiveness of the proposed evasion guidance scheme against multiple pursuing spacecraft