Some Properties of Weak Block Designs

The necessary conditions for the existence of weak designs are given in the form of two inequalities in this paper. The relations among weak block designs (WBDs) , Balanced incomplete block designs ( BIBDs) and differential balanced block designs (DBBDs) are researched.

Some Construction Methods of Optimum Chemical Balance Weighing Designs III

Methods of constructing the optimum chemical balance weighing designs from symmetric balanced incomplete block designs are proposed with illustration. As a by-product pairwise efficiency and variance balanced designs are also obtained.

Variable Selection in Randomized Block Design Experiment

In the experimental field, researchers need very often to select the best subset model as well as reach the best model estimation simultaneously. Selecting the best subset of variables will improve the prediction accuracy as noninformative variables will be removed. Having a model with high prediction accuracy allows the researchers to use the model for future forecasting. In this paper, we investigate the differences between various variable selection methods. The aim is to compare the analysis of the frequentist methodology (the backward elimination), penalised shrinkage method (the Adaptive LASSO) and the Least Angle Regression (LARS) for selecting the active variables for data produced by the blocked design experiment. The result of the comparative study supports the utilization of the LARS method for statistical analysis of data from blocked experiments.

Patterns of cortical reorganization in facial synkinesis:a task functional magnetic resonance imaging study

Facial synkinesis,a sequela of peripheral facial nerve palsy,is characterized by simultaneous involuntary facial movement during a voluntary desired one.Maladaptive cortical plasticity might be involved in the dysfunction of facial muscles.This cohort study investigated the cortical functional alterations in patients with unilateral facial synkinesis,using the task functional magnetic resonance imaging.Facial motor tasks,including blinking and smiling,were performed by 16 patients（aged 30.6 ± 4.5 years,14 females/2 males） and 24 age-and sex-matched healthy controls（aged 29.1 ± 4.2 years,19 females/5 males）.Results demonstrated that activation in the cortico-facial motor representation area was lower during tasks in patients with facial synkinesis compared with healthy controls.Facial movements on either side performed by patients caused more intensive activation of the supplementary motor area on the contralateral side of the affected face,than those on the unaffected side.Our results revealed that there was cortical reorganization in the primary sensorimotor area and the supplementary motor area.This study was registered in Chinese Clinical Trial Registry（registration number： Chi CTR1800014630）.

A collision recovery algorithm using optimal Q parameter based on BIBD in RFID

In this work,an optimal Q algorithm based on a collision recovery scheme is presented. Tags use BIBD-( 16,4,1) codes instead of RN16 s. Therefore,readers can make a valid recognition even in collision slots. A way of getting the optimal slot-count parameter is studied and an optimal Q algorithm is proposed. The theoretical and simulation results show that the proposed algorithm can improve reading efficiency by 100% more than the conventional Q algorithm. Moreover,the proposed scheme changes little to the existing standard. Thus,it is easy to implement and compatible with ISO 18000-6C.

Supplementary motor area deactivation impacts the recovery of hand function from severe peripheral nerve injury

Although some patients have successful peripheral nerve regeneration,a poor recovery of hand function often occurs after peripheral nerve injury.It is believed that the capability of brain plasticity is crucial for the recovery of hand function.The supplementary motor area may play a key role in brain remodeling after peripheral nerve injury.In this study,we explored the activation mode of the supplementary motor area during a motor imagery task.We investigated the plasticity of the central nervous system after brachial plexus injury,using the motor imagery task.Results from functional magnetic resonance imaging showed that after brachial plexus injury,the motor imagery task for the affected limbs of the patients triggered no obvious activation of bilateral supplementary motor areas.This result indicates that it is difficult to excite the supplementary motor areas of brachial plexus injury patients during a motor imagery task,thereby impacting brain remodeling.Deactivation of the supplementary motor area is likely to be a serious problem for brachial plexus injury patients in terms of preparing,initiating and executing certain movements,which may be partly responsible for the unsatisfactory clinical recovery of hand function.

Chinese Remainder Codes

Chinese Remainder Codes are constructed by applying weak block designs and Chinese Remainder Theorem of ring theory. The new type of linear codes take the congruence class in the congruence class ring R/I 1∩I 2∩...∩I n for the information bit, embed R/J i into R/I 1∩I 2∩...∩I n, and asssign the cosets of R/J i as the subring of R/I 1∩I 2∩...∩I n and the cosets of R/J i in R/I 1∩I 2∩...∩I n as check lines. There exist many code classes in Chinese Remainder Codes, which have high code rates. Chinese Remainder Codes are the essential generalization of Sun Zi Codes.

The Existence of BIB Designs

Given any positive integers k3 and λ,let c（k,λ）denote the smallest integer such that u ∈ B（k,λ）for every integer uc（k,λ）that satisfies the congruences λv（v-1）≡0（mod k（k-1））and λ（u-1）≡0（mod k-1）.In this article we make an improvement on the bound of c（k,λ）provided by Chang in[4]and prove that c（k,λ）exp{k3k6}.In particular,c（k,1）exp{kk2}.

Block-Transitive 2-(v,k,1) Designs and Groups E_6(q)

This article is a contribution to the study of block-transitive automorphism groups of 2-（v,k,1） block designs. Let D be a 2-（v,k,1） design admitting a block-transitive, pointprimitive but not flag-transitive automorphism group G. Let kr = （k,v-1） and q = pf for prime p. In this paper we prove that if G and D are as above and q （3（krk-kr ＋ 1）f）1/3, then G does not admit a simple group E6（q） as its socle.

ORTHOGONAL GEOMETRIES OVER FINITE FIELDS WITH CHARACTERISTIC≠2 AND BLOCK DESIGNS

By taking as blocks certain subspace-pairs of an orthogonal geometry over a finite field with characteristic≠2 we construct some new types of BIB designs and PBIB designs whose parameters are also given.

Interaction Between Memory Load and Experimental Design on Brain Connectivity and Network Topology

The conventional approach to investigating functional connectivity in the block-designed study usually concatenates task blocks or employs residuals of task activation.While providing many insights into brain functions,the block design adds more manipulation in functional network analysis that may reduce the purity of the blood oxygenation level-dependent signal.Recent studies utilized one single long run for task trials of the same condition,the so-called continuous design,to investigate functional connectivity based on task functional magnetic resonance imaging.Continuous brain activities associated with the single-task condition can be directly utilized for task-related functional connectivity assessment,which has been examined for working memory,sensory,motor,and semantic task experiments in previous research.But it remains unclear how the block and continuous design influence the assessment of task-related functional connectivity networks.This study aimed to disentangle the separable effects of block/continuous design and working memory load on task-related functional connectivity networks,by using repeated-measures analysis of variance.Across 50 young healthy adults,behavioral results of accuracy and reaction time showed a significant main effect of design as well as interaction between design and load.Imaging results revealed that the cingulo-opercular,fronto-parietal,and default model networks were associated with not only task activation,but significant main effects of design and load as well as their interaction on intra-and inter-network functional connectivity and global network topology.Moreover,a significant behavior-brain association was identified for the continuous design.This work has extended the evidence that continuous design can be used to study task-related functional connectivity and subtle brain-behavioral relationships.

Multi-arm covariate-adaptive randomization

Simultaneously investigating multiple treatments in a single study achieves considerable efficiency in contrast to the traditional two-arm trials.Balancing treatment allocation for influential covariates has become increasingly important in today’s clinical trials.The multi-arm covariate-adaptive randomized clinical trial is one of the most powerful tools to incorporate covariate information and multiple treatments in a single study.Pocock and Simon’s procedure has been extended to the multi-arm case.However,the theoretical properties of multi-arm covariate-adaptive randomization have remained largely elusive for decades.In this paper,we propose a general framework for multi-arm covariate-adaptive designs which also includes the two-arm case,and establish the corresponding theory under widely satisfied conditions.The theoretical results provide new insights into the balance properties of covariate-adaptive randomization procedures and make foundations for most existing statistical inferences under two-arm covariate-adaptive randomization.Furthermore,these open a door to study the theoretical properties of statistical inferences for clinical trials based on multi-arm covariateadaptive randomization procedures.

A topology-transparent MAC scheduling algorithm with guaranteed QoS for multihop wireless network

Due to its character of topology independency, topology-transparent medium access control (MAC) scheduling algorithm is very suitable for large-scale mobile ad hoc wireless networks. In this paper, we propose a new topologytransparent MAC scheduling algorithm, with parameters of the node number and the maximal nodal degree known, our scheduling algorithm is based on a special balanced incomplete block design whose block size is optimized by maximizing the guaranteed throughput. Its superiority over typical other scheduling algorithms is proven mathematically with respect to the guaranteed throughput, the maximal transmission delay, and also the minimal transmission delay. The effect of inaccuracy in the estimation of the maximal nodal degree on the guaranteed throughput is deduced mathematically, showing that the guaranteed throughput decreases almost linearly as the actual nodal degree increases. Further techniques for improving the feasibility of the algorithm, such as collision avoidance, time synchronization, etc., are also discussed.

Super-simple （5, 4）-GDDs of group type g^u

In statistical planning of experiments, super-simple designs are the ones providing samples with maximum intersection as small as possible. Super- simple group divisible designs are useful in constructing other types of super- simple designs which can be applied to codes and designs. In this article, the existence of a super-simple （5, 4）-GDD of group type gU is investigated and it is shown that such a design exists if and only if u ≥ 5, g（u - 2） ≥ 12, and u（u - 1）g^2≡ 0 （mod 5） with some possible exceptions.