Lifelong Sequential Modeling with Personalized Memorization for User Response Prediction

User response prediction, which models the user preference w.r.t. the presented items, plays a key role in online services. With two-decade rapid development, nowadays the cumulated user behavior sequences on mature Internet service platforms have become extremely long since the user's first registration. Each user not only has intrinsic tastes, but also keeps changing her personal interests during lifetime. Hence, it is challenging to handle such lifelong sequential modeling for each individual user. Existing methodologies for sequential modeling are only capable of dealing with relatively recent user behaviors, which leaves huge space for modeling long-term especially lifelong sequential patterns to facilitate user modeling. Moreover, one user's behavior may be accounted for various previous behaviors within her whole online activity history, i.e., long-term dependency with multi-scale sequential patterns. In order to tackle these challenges, in this paper, we propose a Hierarchical Periodic Memory Network for lifelong sequential modeling with personalized memorization of sequential patterns for each user. The model also adopts a hierarchical and periodical updating mechanism to capture multi-scale sequential patterns of user interests while supporting the evolving user behavior logs. The experimental results over three large-scale real-world datasets have demonstrated the advantages of our proposed model with significant improvement in user response prediction performance against the state-of-the-arts.Comment: SIGIR 2019. Reproducible codes and datasets: https://github.com/alimamarankgroup/HPM

Preparation of Thermoelectric Nanocrystals for Energy Applications

Thermoelectric materials, in which a temperature difference creates an electric potential or an electric potential creates a temperature difference, are probably a key to solving global warming and energy shortage problems. There are three thermoelectric effects: the Seebeck effect (temperature to current), Peltier effect (current to temperature), and Thomson effect (conductor heating/cooling). However the efficiency of thermoelectric materials has been rather low for practical applications, including power generation and refrigeration as it requires an optimization of the combination of conflicting material characteristics (i.e., thermal conductivity and electrical conductivity). To date, efforts have been made to capitalize on nanotechnology to create novel semiconducting materials that could finally make thermoelectricity a widely used technology. In my research, I systematically synthesized bismuth (Bi) nanocrystals as one of very important thermoelectric materials by hydrothermal and star-like amphiphilic block copolymer nanoreactor approaches. The size of Bi nanoparticles prepared by employing star-like amphiphilic block copolymer templates was better controlled. The thermoelectric properties of Bi nanocrystals were improved when their crystalline sizes are smaller than 10nm

EFFECTS OF BASKETBALL SHOE ON IMPACT FORCES AND SOFT TISSUE VIBRATIONS DURING DROP JUMP AND UNEXPECTED DROP LANDING

The purpose of this study was to explore the effects of footwear on impact forces and soft tissue vibrations during drop jump and unexpected drop landings. Twelve male basketball players were instructed to wear two types of shoes to execute double-leg landings in each of 6 testing conditions, i.e. 2 landing styles × 3 landing heights, from a customized platform. Joint kinematics, ground reaction force, and soft tissue vibrations of the leg were collected simultaneously. The results indicated that a shoe intervention did not influence the characteristics of the impact force and soft tissue vibrations during active drop jumps. Contrarily, for the unexpected drop landings, the basketball shoe with strong cushioning properties can substantially reduced the peak impact forces as well as decreased the impact frequency and minimized the peak transmissibility

SHOE EFFECTS ON IMPACTS AND MUSCLE RESPONSES IN LOWER EXTREMITY DURING DIFFERENT LANDING TASKS

The aim of this study was to investigate the effect of basketball shoes on impact force and lower limb muscle activity during landings. Twelve male subjects were requested to wear two types of shoes to execute drop jumps and unexpected drop landings. Ground reaction forces, accelerations of the shoe heel-counter, and EMG signals of five lowerlimb muscles were collected simultaneously. During active landing, the intervention of basketball shoe did not significantly change the characteristics of impact force and muscle activity patterns. However, under the condition of related muscles were not being activated properly, the basketball shoe reduced the impacts and decreased the muscle postactivation. This potential effect of footwear may further be developed in preventing sports injury and enhancing metabolic efficiency during landings and/or when fatigued

ACUTE EFFECTS OF FOREARM KINESIO TAPING ON MUSCLE STRENGTH AND FATIGUE IN HEALTHY TENNIS PLAYERS

The aim of this study was to explore the acute effects of Kinesio taping (KT) applied over the wrist extensors and flexors on muscle strength and endurance. Fourteen participants completed 50 consecutive maximal concentric wrist extension and flexion repetitions at 60 °/s and 210 °/s in KT, placebo taping, and no taping conditions. There was no significant KT effect on the strength output (peak moment and peak / average power). KT reduced work fatigue and induced an increased regression of torque compared to no taping at 60 °/s. These findings provide preliminary evidences suggesting that KT may not be able to modulate strength production in healthy athletes immediately, but would have a significant positive effect on muscle fatigue resistance during repeated concentric muscle actions

A multi-factor analysis of revision in total hip replacement using the collarless-polished-tapered stems with different cups

Objective: Collarless-polished-tapered (CPT) stems have been widely used in total hip replacement (THR). Given that various types of cups are combined with CPT in clinical practice, however, what cup type performs the best for use with CPT is still unclear. This study aimed to investigate the effects of three types of commonly used cups with CPT on revision and survival life using multi-factor analysis.Methods: This study is a cohort study using the data between October 1998 to September 2021. The data of THR patients with ZCA All-poly Acetabular Cup, Continuum Acetabular System, and Trilogy Acetabular System with CPT were collected from several hospitals in the UK. The patients aged from 20 to 97 (n = 5981, 2345 male and 3636 female). Age, gender, body mass index, diagnosis, surgeon grade, cup material, cup size, surgical approach, survival life, complications, and Harris hip scores (HHS) were analyzed in relation to revision status. SPSS statistical software was used to analyze the relationship among various factors. The main statistical methods included chi-square with cross tables, analysis of variance (ANOVA) and survival analysis.Results: The results in relation to HHS shows that the continuum cup has the best outcome in the postoperative period of 1 and 5 years (1 year = 90.7, 5 years = 91.3; P < 0.001); the Trilogy cup was the second (1 year = 88.4, 5 years = 87.3; P < 0.001); and the ZCA cup was the third (1 year = 84.6, 5 years = 82.4; P < 0.001). However, the Trilogy cup performed the best regarding survival life on revision while the Continuum cup was the worst.Conclusion: When the CPT stem is combined with different cups, the trilogy cup shows the best characteristics in terms of survival trends with revision ratios compared with the continuum and ZCA cups, and is therefore recommended by this study

IS THE HIGH-TOP SHOE MORE PROTECTIVE IN LANDING ON A TILTED SURFACE: A KINEMATIC AND ELECTROMYOGRAPHIC EVALUATION

The purpose of this study was to explore the effect of high-top and low-top shoes on ankle inversion kinematics and pre-landing EMG activation of ankle evertor muscles during the landing on a combined inverted and plantarflexed surface. Thirteen male subjects were instructed to wear high-top & low-top shoes to execute self-initiated drop landings in each of the 8 landing conditions, i.e. 2 shoes × 4 surface conditions, on an inverted (or combined plantarflexed) platform. Ankle inversion kinematics and the EMG from the tibialis anterior, peroneal longus, and peroneus brevis muscles were collected simultaneously. The results indicated that shoe collar heights did not influence the ankle inversion kinematics during landing. However, wearing high-top shoes resulted in a significant posterior onset time of the tibialis anterior and peroneus brevis muscles, and lowered the pre-landing EMG activation of ankle evertor muscles prior to foot contact during landing on the inverted surface

THE DYNAMIC CHARACTERISTICS OF THE PLANTAR PRESSURE IN THREE TYPICAL BADMINTON FOOTWORK PATTERNS

The purpose of this study was to investigate the dynamic characteristics of plantar pressure in the three-badminton footwork patterns (left-forward lunging step, LFLS, right-forward lunging step, RFLS, backward revolve to jump, BRJ). Twelve elite national-level male badminton athletes were recruited while performing the three typical footwork patterns tests in a laboratory-simulated badminton court. The results of the present study demonstrate that the normalized mean peak pressures (MPP) were significantly higher under the hallux and the 1st to 2nd metatarsals than other areas in the toe-off (TO) phase when performing the three footwork patterns. In the process of touching down (TD), both LFLS and RFLS showed significantly higher loads on the rearfoot and the lateral of the foot. Thus, the badminton players should be paying attention to modulating the load strategies on the front-foot, rear-foot, and lateral of the foot regions when performing the different footwork patterns, and select the appropriate footwear that can disperse the higher loads of the target areas to avoid excessive concentration of the plantar pressures