6G New Multiple Access Technology

As a basic technology at physical layer of mobile communications,non-orthogonal multiple access has been attracting wide attention across the academia and the industry.During the standardization of the fifth-generation(5G)of mobile communications,3GPP conducted preliminary study on non-orthogonal multiple access without reaching the consensus to standardize the technology.

Motivation to Study a Second Foreign Language: A Case of Chinese University Learners of German

Not much research has been done on motivation to study a second,third or even fourth foreign language though learners of such languages have been increasing.To contribute to this,the present study examined German learning motivation of Chinese university students at different proficiency levels.A total of 297 German learners at three different proficiency levels at a university in Beijing filled in the questionnaires,of whom 191 answered the open-ended question and 50 were informally interviewed.Analyses of the data revealed the following major findings;(1)most respondents at cach proficiency level had limited access to and little chance to use German,liked the language,studied it(very)hard and did not think the language was difficult,(2)students at different proficiency levels studied German for similar reasons such as major study/research,further education,future career,interest in foreign language learning and German,and(3)students at higher proficiency levels perceived German to be more difficult and worked harder on it.Students at higher proficiency levels were both integratively and instrumentally more motivated to study German and had greater motivation intensity as well.It is clear that students at different proficiency levels were motivated to study German and that students at the advanced level tended to be more integratively motivated than those at the beginning level.Based on these findings,some suggestions are discussed.

Semi-asynchronous personalized federated learning for short-term photovoltaic power forecasting

Accurate forecasting for photovoltaic power generation is one of the key enablers for the integration of solar photovoltaic systems into power grids.Existing deep-learning-based methods can perform well if there are sufficient training data and enough computational resources.However,there are challenges in building models through centralized shared data due to data privacy concerns and industry competition.Federated learning is a new distributed machine learning approach which enables training models across edge devices while data reside locally.In this paper,we propose an efficient semi-asynchronous federated learning framework for short-term solar power forecasting and evaluate the framework performance using a CNN-LSTM model.We design a personalization technique and a semi-asynchronous aggregation strategy to improve the efficiency of the proposed federated forecasting approach.Thorough evaluations using a real-world dataset demonstrate that the federated models can achieve significantly higher forecasting performance than fully local models while protecting data privacy,and the proposed semi-asynchronous aggregation and the personalization technique can make the forecasting framework more robust in real-world scenarios.

Catalysts or Barriers?The Impacts of Natural Disasters on Internal Labor Migration in China

This paper discusses ways in which negative economic shocks captured by natural disasters can shape internal labor migration in China.The impact of negative economic shocks on migration depends on the combination of two opposite driving forces:(i)negative economic shocks can make staying in the affected area less profitable,thus enhancing returns to migration;(ii)the shocks can make it more difficult to migrate out,thus inducing a higher fixed cost of migration.Based on a nationwide dataset of China,this paper shows that when natural disasters were not severe,they caused migration out of rural areas.With sufficiently severe damage,however,the negative effect of natural disasters could be mitigated by villages'prior migrant networks.Specifically,with a severe shock,only clan members were able to migrate in response to natural disasters and enjoyed the complementary effects of prior migrant networks,as they could receive more help from social capital.

Preferential orientation of tracer spheroids in turbulent channel flow

Axis-symmetric spheroids, such as rod-like and disk-like particles, have been found to orient preferentially in near-wall turbulence by both experiment and numerical simulation. In current work we examined the orientation of inertialess spheroids in a turbulent channel flow at medium friction Reynolds number Reτ=100 given based on the half of channel height. Both elongated prolate spheroid and flat oblate spheroid are considered and further compared with the reference case of spherical particle. The statistical results show that in near wall region the prolate spheroids tend to align in the streamwise direction while the oblate spheroids prefer to orient in the wallnormal direction, which are consistent with earlier observation in low Reynolds number (Reτ=180)wall turbulence. Around the channel center we found that the orientation of spheroids is not fully isotropic, even though the fluid vorticity are almost isotropic. The mechanism that gives rise to such particle orientations in wall-turbulence has been found to be related to fluid Lagrangian stretching and compression (Zhao and Andersson 2016). Therefore, we computed the left Cauchy-Green strain tensor along Lagrangian trajectories of tracer spheroids in current flow field and analyzed the fluid Lagrangian stretching and compression. The results indicated that, similar to the earlier observations, the directions of the Lagrangian stretching and compression in near-wall region are in the streamwise and wall-normal directions, respectively. Furthermore, cross over the channel the prolate spheroids aligned with the direction of Lagrangian stretching but oblate spheroids oriented with the direction of Lagrangian compression. The weak anisotropy of orientations of fluid Lagrangian stretching and compression observed at the channel center could be the reason for the aforementioned modest anisotropic orientation of spheroids in channel central region.

EFFICIENT FITTING RANGE FOR GLUCOSE MEASUREMENT WITH OPTICAL COHERENCE TOMOGRAPHY

Studies of non-invasive glucose measurement with optical coherence tomography(OCT)in tissue-simulating phantoms and biological tissues show that glucose has an effect on the OCT signal slope.Choosing an efficient fitting range to calculate the OCT signal slope is important because it helps to improve the precision of glucose measurement.In this paper,we study the problem in two ways:(1)scattering-induced change of OCT signal slope versus depth in intralipid suspensions with different concentrations based on Monte Carlo(MC)simulations and experiments and(2)efficient fitting range for glucose measurement in 3%and 10%intralipid.The results show that the OCT signal slope expresses a contrary change with scattering coefficient below a certain depth in high intralipid concentrations,so that there is an effective fitting depth.With an efficient fitting range from 100μm to the effective fitting depth,the precision of glucose measurement can be 4.4mM for 10%intralipid and 2.2mM for 3%intralipid.

Preface to the Special Issue of the International Symposium on Single‐Atom Catalysis(ISSAC‐2016)

Catalysis is one of the most important chemical processes for production of goods and for environmental remediation.Almost 80% of chemical manufacturing involves either heterogeneous or homogeneous catalysts, mostly consisting of expensive noble metals. Designing highly active, selective and stable catalysts with most efficient use of rare and expensive metals becomes Grand Challenge of heterogeneous catalysis and is critical to the sustainable development of our planet.

Editorial

Additive manufacturing,is originally known as rapid prototyping manufacturing,and nowadays more commonly known as 3D printing.It is a manufacturing method based on the principle of"discrete/stacking",which transfers the traditional multidimensional"subtractive"manufacturing into the two-dimensional manufacturing by layer-by-layer additive stacking.

A Fast and Accurate LEO Satellite-Based Direct Position Determination Assisted by TDOA Measurements

This paper focuses on the trusted vessel position acquisition using passive localization based on the booming low-earth-orbit(LEO) satellites. As the high signal-to-noise ratio(SNR) reception cannot always be guaranteed at LEO satellites, the recently developed direct position determination(DPD)is adopted. For LEO satellite-based passive localization systems, an efficient DPD is challenging due to the excessive exhaustive search range leading from broad satellite coverage. In order to reduce the computational complexity, we propose a time difference of arrival-assisted DPD(TA-DPD) which minimizes the searching area by the time difference of arrival measurements and their variances. In this way, the size of the searching area is determined by both geometrical constraints and qualities of received signals, and signals with higher SNRs can be positioned more efficiently as their searching areas are generally smaller.Both two-dimensional and three-dimensional passive localization simulations using the proposed TA-DPD are provided to demonstrate its efficiency and validity. The superior accuracy performance of the proposed method, especially at low SNRs conditions, is also verified through the comparison to conventional two-step methods. Providing a larger margin in link budget for satellite-based vessel location acquisition,the TA-DPD can be a competitive candidate for trusted marine location service.

Two New Multi-component BKP Hierarchies

We firstly propose two kinds of new multi-component BKP （mcBKP） hierarchy based on the eigenfunction symmetry reduction and nonstandard reduction, respectively. The first one contains two types of BKP equation with self-consistent sources whose Lax representations are presented. The two mcBKP hierarchies both admit reductions to the k-constrained BKP hierarchy and to integrable （1＋1）-dimensional hierarchy with self-consistent sources, which include two types of SK equation with self-consistent sources and of hi-directional SK equations with self-consistent

IoT Intelligence Empowered by End-Edge-Cloud Orchestration

To support intelligent Internet of Things(IoT)applications,such as autonomous driving,smart city surveillance,and virtual reality(VR)/augmented reality(AR),cloud services are expected to be pushed to the proximity of IoT devices for quality performance.For instance,to facilitate safe autonomous driving,the service delay of most vehicular applications is required to be within milliseconds,and any information delay may result in dangerous on-road conditions.

INTEGRATED TERRESTRIAL-SATELLITE NETWORKS：PART ONE

The rapid growing data traffic brings more and more pressure to the wireless networks,which is predicted to increase by over 10,000 times in the next 20 years.However,currently,there is still large number of population without coverage of mobile service.In addition

Aqueous Tape Casting Process with Styrene-acrylic Latex Binder

A commercial styrene-acrylic latex binder has been investigated as a good binder for aqueous Al-2O-3 suspensions tape-casting process. This paper focuses on the forming film mechanism of latex binder, the rheological behaviors of the suspensions, physical properties of green tapes and drying process of aqueous slurries with latex binder system. The drying process of the alumina suspensions is shown to follow a two-stage mechanism (the first stage: evaporation controlled process; and the second stage: diffusion controlled process). During the drying stage of the suspensions, the compressive force presses the latex particles and makes them be distorted, which results in cross-linking structure in contacted latex particles of the solidified tapes.A smooth-surface and high-strength green tape was fabricated by aqueous tape casting with latex binder system. The results from the SEM images of the crossing section microstructure of green tapes show that the latex is a very suitable binder for aqueous tape casting.

Simulation Studies of an Integrated Overcurrent Relay Protection Scheme for Distribution Systems

This paper presents an integrated protection technique for power distribution systems. A novel integrated protection scheme based on overcurrent protection technique for distribution system is described, in which a specially designed protection relay is installed at each substation of a network and responsible for the protection of every line sections connected to the substation busbar The conventional directional overcurrent and the new adaptive accelerated protection algorithms with multiple settings are implemented into the relay to cover all the protected line sections. The paper includes studies of a typical multi section distribution network to demonstrate the principle of the scheme. Studies show that the new scheme not only offer the new protection features for individual power line section, but also provide the characteristics of integrated protection.

Preface tovirtual special issue of biocatalysis

Catalysis plays an important role in human civilization and economic development.Every breakthrough related to the field of catalysis has great impact on our everyday lives.To achieve harmonious development between human and nature through developing chemical processes with environmental friendliness and atom economy,the improvement and innovation of catalytic systems have drawn great attention.Biocatalysis is the engine of life from the very beginning,which is the example that we always learn from,mimic,and aim to surpass in scientific research and industrial development.The goal of the development of biocatalysis technology is tomake our industrial manufacturing go undermild conditions as nature does.However,the current situation of biocatalysis application is still far from the ultimate aim,providing countless opportunities for further development.

Video-based construction vehicles detection and its application in intelligent monitoring system

While vehicle detection on highways has been reported before, to the best of our knowledge, intelligent monitoring system that aims at detecting hydraulic excavators and dump trucks on state-owned land has not been explored thoroughly yet. In this paper, we present an automatic, video-based algorithm for detecting hydraulic excavators and dump trucks. Derived from lessons learned from video processing, we proposed methods for foreground detection based on an improved frame difference algorithm, and then detected hydraulic excavators and dump trucks in the respective region of interest. From our analysis, we proposed methods based on inverse valley feature of mechanical arm and spatial-temporal reasoning for hydraulic excavator detection. In addition, we explored dump truck detection strategies that combine structured component projection with the spatial relationship. Experiments on real-monitoring sites demonstrated the promising performance of our system.

弥异所105:大理天空之境

形式洱海边有不少打卡景点,主角总是大理的天空、云彩、像镜子一样的水面,加上干净的人工道具点睛。天梯就是其中之一。三点透视的错觉使天梯直通云端,扶手栏杆的缺失使天梯更加纯粹,而整体色调的干净使天梯更加抽象。空间如此美妙的天梯吸引了众多年轻人前来打卡,有人选择迈向天空留下背影,有人尝试追逐太阳拂弄清风,有人愿意平躺尽头比肩浮云。

Consequence and Path Analysis of Balanced Scorecard Usage： Evidence From Chinese Public Hospitals

Based on a questionnaire survey of Chinese public hospitals, this paper explores the consequence and realization path of balanced scorecard （BSC, hereafter） usage. The results show that BSC usage can improve hospital performance remarkably. With the structural equation model analysis, we further find that, this function is realized in an indirect way through the perception of organizational fairness and organizational commitment. The BSC has direct effect to improve the perception of organizational fairness and organizational commitment, which further influence the performance. The results not only complement empirical evidences for BSC usage, but also provide guidance to regulators and hospitals to implement BSC in compensation contract.

ON SHAPE PRESERVING EXTENSION AND APPROXIMATION OF FUNCTIONS

We establish the concept of shapes of functions by using partial differential inequalites. Our definition about shapes includes some usual shapes such as convex,subharmonic,etc.,and gives many new shapes of functions.The main results show that the shape preserving approxi- mation has close relation to the shape preserving extension.One of our main results shows that if f∈C(Ω)has some shape defined by our definition,then f can be uniformly approximated by polynomials P_n ∈p_n(n∈N)which have the same shape in Ω,and the degree of the ap- proximation is Cω(f,n^(-β))with constants C,β>0.

ZTE Communications Special Issue on Recent Advances in Smart Grid

The smart grid is the next generatiou electric： grid that enables effi- cient, intelligent, and economical power generation, transmission, and distribution. It has attracted significant attentions and become a global trend due to the immense potential benefits including en- hanced reliability and resilience, higher operational efficiency, more efficient energy consumption, and better power quality. This special issue expects to address smart grid issues related to data sensing, data communications and data networking, including high-level ideology/methodology, concrete smart grid inspired data communications and networking technolngies, smart grid system ar- chitecture, QoS, energy-efficiency, and fault tolerance in smart grid systems, management of smart grid systems, and real-world deploy- ment experiences.