An electromyographic investigation of asymmetric lifting and moving of a load: II. Effects of load lift from knuckle to target shelves

The range of normalized electromyography (EMG) values when lifting and moving a 5.84 kg box was between 0.08 and 0.63. The right iliocostalis and the left erector spinae showed decreased muscle activity with increasing asymmetry. The right erector spinae and the left and the right external obliques showed significant increases in muscle activity at 90° asymmetry. The left and the right iliocostalis, the left erector spinae, and the right external oblique showed significant reductions in muscle activity for the sternum height when compared to the knuckle height. The right erector spinae exhibited a significant increase at reach height when compared to the knuckle height. The muscle activity for the knuckle lift was significantly lower than the floor lift. The average decrease in muscle activity was approximately 68%. Consequently, asymmetric lifting and moving tasks should be performed from a knuckle height to sternum height. © 2009 Wiley Periodicals, Inc.     

An electromyographic investigation of asymmetric lifting and moving of a load: I. Effects of load lift from floor to target shelves

The range of normalized electromyography (EMG) values when lifting and moving a 5.84 kg box was between 0.12 and 0.77. The right iliocostalis and the right and the left external obliques showed significant increases in muscle activity at 90° of asymmetry. The average percentage increase for the stated muscles was 62.3% when compared to muscle activity at 0°. The left external oblique also responded significantly at 60° of asymmetry when compared to 0°. The knuckle, sternum, and reach heights significantly affected the left iliocostalis and the left and right erector spinae muscles. The average percentage increases in the stated muscles were 74.4% at knuckle height, 126.1% at sternum height, and 143.3% at reach height, when compared to floor level. Significant increases in muscle activity for the right iliocostalis and the right external oblique were registered only at the sternum and at the reach heights. For manual materials handling (MMH), an endeavor should be made to avoid asymmetric lifting and moving at 90° and from the floor level and to the reach height. To minimize the risk of back injury, the MMH task should be performed preferably within an asymmetry of 30° but not exceeding 60° asymmetry. © 2009 Wiley Periodicals, Inc.     

3D foot shape generation from 2D information

Two methods to generate an individual 3D foot shape from 2D information are proposed. A standard foot shape was first generated and then scaled based on known 2D information. In the first method, the foot outline and the foot height were used, and in the second, the foot outline and the foot profile were used. The models were developed using 40 participants and then validated using a different set of 40 participants. Results show that each individual foot shape can be predicted within a mean absolute error of 1.36 mm for the left foot and 1.37 mm for the right foot using the first method, and within a mean absolute error of 1.02 mm for the left foot and 1.02 mm for the right foot using the second method. The second method shows somewhat improved accuracy even though it requires two images. Both the methods are relatively cheaper than using a scanner to determine the 3D foot shape for custom footwear design.     

Abnormal pathways in the genu of the corpus callosum in schizophrenia pathogenesis: a proteome study

Abnormalities within the corpus callosum (CC) have been identified in schizophrenia brains and are thought to affect inter-hemispheric communication, which in-turn is postulated to underlie some schizophrenia symptoms. Furthermore, hemisphere asymmetry of fractional anisotropy, detected by diffusion tensor imaging, left-higher-than-right- has been observed in normal individuals in the CC genu. This asymmetry is significantly reduced in the left CC genu of first-episode and chronic schizophrenia subjects. We examined the protein expression profile of the CC genu, including the profiles from the left and right hemisphere, in schizophrenia brains compared to controls using two-dimensional gel electrophoresis and mass spectrometry techniques. Proteins involved in cytoskeletal structure and function, neuroprotective function and energy metabolism were identified as differentially expressed, suggesting these proteins may underlie abnormal CC genu structure and function. Proteins in these functional categories also displayed different expression levels in the left CC genu compared to the right in both control and schizophrenia brains and therefore may be involved in normal CC asymmetry and reduced asymmetry in schizophrenia individuals. This initial pool of protein candidates and abnormal functional pathways opens up avenues for further investigation of molecular mechanisms involving the CC in schizophrenia pathogenesis and symptoms.     

Automated detection of breast tumors using the asymmetry approach

A method for automated detection of breast tumors in mammograms is presented. The method uses the asymmetry principle: Strong structural asymmetries between corresponding regions in the left and right breast are taken as evidence for the possible presence of a tumor in that region. Asymmetry detection is achieved in two steps. First, mammograms are aligned, compensating for possible differences in size and shape between the two breasts. Second, asymmetry between corresponding positions is determined using a combination of several asymmetry measures, each responding to different types of asymmetries. Results obtained with a set of mammograms indicate that this method can improve the sensitivity and reliability of systems for automated detection of breast tumors.     

A method for solving a problem of possibilistic programming

The models of possibilistic programming considered in [1–3] are generalized to the case when the binary relations that relate the left and right sides in the model of constraints are fuzzy. The corresponding mathematical formalism for describing models of this class is developed. A method for solving the problem is proposed. The capabilities of the approach are demonstrated in numerical examples.     

CT图像的不对称性计算方法及应用研究

在医学上,人的头部一般认为是对称的,所以经常通过计算这种对称性来诊断一些疾病.提出了一种方法,通过不对称性原理对胆脂瘤疾病的辅助诊断.首先从CT图像中提取头部图像,确定一个关于头部左右两边总体上的对称面,然后利用对称面来计算左右中耳区域CT值的不对称性,最后,根据它们之间的不对称性来辅助医生诊断胆脂瘤疾病.同时,还提出了一种中耳区域分割方法,进一步提高了胆脂瘤计算机辅助诊断效率和准确率.     

Automatic evaluation of the degree of facial nerve paralysis

Facial paralysis affects both mental and physical health of patients. Evaluation of facial paralysis in clinical practice is normally based on the static facial asymmetry at the maximal movement state and the dynamic change of facial muscle movement. However, most existing research only considers one of these two aspects when evaluating the degree of facial paralysis. This will result in an incomplete utilization of the diagnosis information leading to a low evaluation accuracy, or even misjudgment. In this paper, a novel method is presented for evaluating the degree of facial paralysis considering both static facial asymmetry and dynamic transformation factors. A quantitative approach of static facial asymmetry based on local mirror asymmetry is proposed. The method compares the differences of the corresponding local regions between both sides of the face. This makes it effective analyzing the left and right side asymmetry for abnormal faces. A quantitative evaluation of static facial asymmetry is achieved through three steps: localization of local facial regions, extraction of asymmetry features and quantification of bilateral facial asymmetry. Once the static facial asymmetry is quantified, its dynamic counterparts can be calculated using the speed of changings in different regions caused by facial muscle movement. Then we combine the static and dynamic quantification results to evaluate the degree of facial nerve paralysis. The efficiency and effectiveness of the proposed method have been tested using our facial paralysis database with 62 patients. The experiments show that our method produced encouraging performance compared with ground truth.     

低调整率的广义AVL树及其统一重平衡方法

针对传统AVL(Adelson-Velskii and Landis)树重平衡算法代码量大、流程复杂、调整率过高的问题,提出一种统一重平衡算法,并提出广义AVL树的概念。统一重平衡算法能对AVL树的失衡节点进行自动分类、调整,取消了传统重平衡方法中的四种旋转操作。广义AVL树放松了AVL树的平衡约束,允许左右子树树高相差不超过N(N≥1),当更新操作(插入/删除)执行后,广义AVL树只在平衡约束条件不满足时采用统一重平衡算法进行调整。理论分析与实验结果表明,广义AVL树的调整率随着N的增大而显著降低:N为5时,调整率低于4%;N为13时调整率低于千分之一。广义AVL树的调整率远低于红黑树等经典数据结构,适合并发应用。     

Symmetry of the elbow kinematics during racing wheelchair propulsion

The purpose of this study was to establish whether bilateral symmetry exists during wheelchair propulsion in the elbow movement pattern of trained wheelchair racers. Seven endurance-trained wheelchair racers volunteered to participate in the study. Each subject was recorded by two-dimensional video analysis while pushing on a single-roller wheelchair ergometer at 14 mph (6.58 ms^-1) in their own racing wheelchair. The range of elbow flexion, elbow orientation and selected timing parameters including cycle time and time spent in contact with the handrim (propulsion phase) were obtained from both left and right sides. Wilcoxon Matched-Pairs Signed-Ranks tests determined the differences between the left and right sagittal plane images of wheelchair propulsion. Furthermore, the Bland-Altman method determined the agreement between the left and right sagittal plane images. The results indicated that the propulsion phase, elbow height and elbow angular displacement characteristics were not significantly different between right and left sides. The right elbow was higher than the left during the recovery phase, but the magnitude of this difference was only 0.03 m (N.S). Factors associated with chair design and the athlete's posture may have contributed to the small differences noted between left and right sides. In conclusion, the results appear to suggest that the assumption of bilateral symmetry of the elbow movement pattern during wheelchair propulsion is valid for the group. However, it is important to note that asymmetries exist in individuals and further research is warranted.     

Transformations of solvents and spectral factors of matrix polynomials,and their applications†

The relationships between solvents and spectral factors of a high-degree matrix polynomial are explored. Various new transformations are developed to convert right (left) solvents into spectral factors and vice versa. The transformation of a right (left) solvent to a left (right) solvent is also established. The newly established algorithms are then applied to determine the spectral factorization of a matrix polynomial for optimal control problems. The developed algebraic theory enhances the capability of the analysis and synthesis of a system described by a high-degree matrix differential equation.     

Mapping canopy height using a combination of digital stereo‐photogrammetry and lidar

Ranging techniques such as lidar (LIght Detection And Ranging) and digital stereo‐photogrammetry show great promise for mapping forest canopy height. In this study, we combine these techniques to create hybrid photo‐lidar canopy height models (CHMs). First, photogrammetric digital surface models (DSMs) created using automated stereo‐matching were registered to corresponding lidar digital terrain models (DTMs). Photo‐lidar CHMs were then produced by subtracting the lidar DTM from the photogrammetric DSM. This approach opens up the possibility of retrospective mapping of forest structure using archived aerial photographs. The main objective of the study was to evaluate the accuracy of photo‐lidar CHMs by comparing them to reference lidar CHMs. The assessment revealed that stereo‐matching parameters and left–right image dissimilarities caused by sunlight and viewing geometry have a significant influence on the quality of the photo DSMs. Our study showed that photo‐lidar CHMs are well correlated to their lidar counterparts on a pixel‐wise basis (r up to 0.89 in the best stereo‐matching conditions), but have a lower resolution and accuracy. It also demonstrated that plot metrics extracted from the lidar and photo‐lidar CHMs, such as height at the 95th percentile of 20 m×20 m windows, are highly correlated (r up to 0.95 in general matching conditions).     

Automatic detection of the breast border and nipple position on digital mammograms using genetic algorithm for asymmetry approach to detection of microcalcifications

The presence of microcalcifications in breast tissue is one of the most incident signs considered by radiologist for an early diagnosis of breast cancer, which is one of the most common forms of cancer among women. In this paper, the Genetic Algorithm (GA) is proposed for automatic look at commonly prone area the breast border and nipple position to discover the suspicious regions on digital mammograms based on asymmetries between left and right breast image. The basic idea of the asymmetry approach is to scan left and right images are subtracted to extract the suspicious region. The proposed system consists of two steps: First, the mammogram images are enhanced using median filter, normalize the image, at the pectoral muscle region is excluding the border of the mammogram and comparing for both left and right images from the binary image. Further GA is applied to magnify the detected border. The figure of merit is calculated to evaluate whether the detected border is exact or not. And the nipple position is identified using GA. The some comparisons method is adopted for detection of suspected area. Second, using the border points and nipple position as the reference the mammogram images are aligned and subtracted to extract the suspicious region. The algorithms are tested on 114 abnormal digitized mammograms from Mammogram Image Analysis Society database.     

Computer tracking of objects moving in space

A method is developed to represent movement of convex blocks in three-dimensional space from a sequence of two-dimensional camera images. The goals are to determine the objects' movement toward or away from the camera as well as left/right and up/down movement in the image plane and to build models of the blocks. The movement information is used as part of a hierarchical matching process that determines the correspondence of blocks between scenes.     

脑电技术在文化创意产品情感化设计中的应用

为了获取消费者对于文化元素的偏好，借助PAD 情感量表将文化元素图片按照愉 悦度值和情感状态分组，再通过脑电仪记录不同愉悦度的文化元素图片诱发的脑电波。以实验 得出喜欢的文化元素为基础，设计出了一套蜀文化调味瓶。脑电实验结果表明：在喜欢的图片 刺激下，左额极α 波平均功率显著低于右额极；在不喜欢的图片刺激下，右额极α 波平均功率 显著低于左额极；在喜欢的图片刺激下的中央区域的α 波平均功率显著高于不喜欢的图片刺激。 研究发现，根据额叶α 波不对称性理论，α 波频域特征可用于研究用户情感特征。该方法能够 帮助设计师进行文化创意产品设计，使其满足消费者的感性需求。     

On evolution of open dynamical systems: Some algebraic methods

Open dynamical systems which are governed by a finite number of ordinary differential equations with controls (time-dependent control parameters) constitute a large and important class of models for practical purposes. In the last few years, there has been considerable interest and progress in algebraic methods for solving the equations of the form (*) $$\dot x\left( t \right) = L_0 x\left( t \right) + \sum\limits_{j = 1}^r {u\left( t \right)L_i x\left( t \right)} ,$$ i.e. bilinear models. In this paper, intended as an expository introduction to the main results of system-theoretic approach to the modelling of open systems, a new “polynomial” representation of solutions to (*) is discussed.     

A comparison of low back kinetic estimates obtained through posture matching, rigid link modeling and an EMG-assisted model

This study examined errors introduced by a posture matching approach (3DMatch) relative to dynamic three-dimensional rigid link and EMG-assisted models. Eighty-eight lifting trials of various combinations of heights (floor, 0.67, 1.2 m), asymmetry (left, right and center) and mass (7.6 and 9.7 kg) were videotaped while spine postures, ground reaction forces, segment orientations and muscle activations were documented and used to estimate joint moments and forces (L5/S1). Posture matching over predicted peak and cumulative extension moment (p < 0.0001 for all variables). There was no difference between peak compression estimates obtained with posture matching or EMG-assisted approaches (p = 0.7987). Posture matching over predicted cumulative (p < 0.0001) compressive loading due to a bias in standing, however, individualized bias correction eliminated the differences. Therefore, posture matching provides a method to analyze industrial lifting exposures that will predict kinetic values similar to those of more sophisticated models, provided necessary corrections are applied.     

Three-dimensional spinal motion and risk of low back injury during sheep shearing

Sheep shearers are known to work in sustained flexed postures and have a high prevalence of low back pain (LBP). As sustained posture and spinal movement asymmetry under substantial loads are known risk factors for back injury our aim was to describe the 3D spinal movement of shearers while working. We hypothesised that thoraco-lumbar and lumbo-sacral movement would be tri-axial, asymmetric, and task specific. Sufficient retro-reflective markers were placed on the trunk of 12 shearers to define thoraco-lumbar and lumbo-sacral 3D motion during three tasks. Thoraco-lumbar movement consistently involved flexion, left lateral flexion, and right rotation. Lumbo-sacral movement consistently involved right lateral flexion in flexion with minimal rotation. Shearers therefore work in sustained spinal flexion where concurrent, asymmetric spinal movements into both lateral flexion and rotation occur. These asymmetric movements combined with repetitive loading may be risk factors leading to the high incidence of LBP in this occupational group.