猪肌纤维特性的研究进展

肌纤维是构成肌肉的基本单位，肌纤维的特性直接影响到猪肉的品质。现就猪肌纤维的组成、肌纤维的转化规律、肌纤维特性的各种影响因素、肌纤维与胴体性状和肉质性状间的关系及肌纤维的基因定位等作一综述。     

大河乌猪肉质特性研究

此文系统研究了大河乌猪的肉质特性。经四川农业大学动物科技学院现场测定及实验室分析测定98个肉质指标，结果表明，大河乌猪肉色玲珑剔透如玛瑙，肌肉系水力强，pH较高，肌内脂肪含量高(5．24％)，肌肉组织学特性良好，保持了其亲本大河猪在氨基酸和脂肪酸组成与结构上的优良特性大河乌猪种群又属应激抵抗群体，具备抵抗应激环境的遗传基础。     

定远猪及其一代杂种猪胴体,肌肉品质的比较研究

本试验将定远猪分别与长白、大约克和杜洛克杂交,对所产Ｆ１代肉猪作胴体性状和肌肉品质分析比较,结果发现,（１）要交Ｆ１代猪眼肌面积增大,眼肌重增加,前者分别比定远猪对照组提高０．９１￣９．３４ｃｍ＾２,后者分别比对照组高２０－４７％,达到显著水平;（２）各杂交系胴体瘦肉量增国极显著（１．９２￣３．１７ｋｇ,Ｐ〈０．０１）,其肉详细交对照组提高７．８５￣９．５３个百分点;（３）杂交Ｆ１代猪皮重均明显减     

基于特征识别的3维人脸动画模型自动构造

针对3维人脸动画应用中,需要手工事先标定肌肉模型的控制点、工作区域和设置各种计算参数,造成工作量大、修改困难、移植性差等弊端,提出自动构造各种肌肉模型及确定它们计算参数的方法。研究工作包括:综合运用法向量变化率、高斯曲率、高斯纹理模型等参数研究3维人脸几何及纹理特征的快速检测方法;设计基于邻域生长和候选点聚类分析的识别算法来识别人脸五官部位的特征点;在此基础上,自动确定各种肌肉模型的位置结构、工作区域和计算参数,实现人脸动画所需的肌肉模型构造和装配的自动化。应用工作结果表明,基于特征识别的3维人脸动画肌肉模型自动构造方法移植性好、精度较高,提高了动画建模工作的效率。     

提高猪肉品质的短期营养措施初探

近年来，遗传改良和饲养技术的进步在提高猪生长速度和胴体瘦肉率的同时，在南方高温季节也不同程度出现肉质差的现象，集中表现在肉色苍白、质地较软、滴水损失严重；伴随β－兴奋剂类物质的全面禁止，更加剧了这一问题的严重性，其原因主要在β－兴奋剂抑制了屠宰后的糖酵解（邓波，2002），减缓了肌肉pH的下降。针对此，笔者曾做了维生素E和有机硒改善肉质的试验，但效果不理想，且增加饲养成本较高。而通过屠宰前在猪饲粮短期添加某些物质来改善肉质的研究报道较多，本人选择了在饲粮中短期添加有机镁和色氨酸对改善肉质进行了尝试。1…     

胆囊收缩素主动免疫对猪生产性能及胴体品质、肉质的影响

此试验研究胆囊收缩素(CCK)主动免疫对猪生产性能及胴体品质、肉质的影响。试验结果表明,CCK主动免疫诱发高强度的免疫应答,试验组抗体滴度在第71天比对照组高67.73%,差异极显著(P<0.01);试验组猪的日增重比对照组提高21.23%,日采食量提高16.23%,料重比降低4.86%,但均差异不显著;试验猪屠宰体重比对照组增加12.68%,背膘厚、胴体长、眼肌面积与对照组差异不显著,CCK主动免疫对猪的肉色评分、大理石纹评分、pH、滴水损失以及肌肉的脂肪/蛋白质比例没有影响。结果显示,CCK主动免疫诱发试猪高强度的免疫应答,提高猪的生产性能,但不影响猪的胴体品质和肉质。     

东北民猪、长白猪和杂种猪生长肥育的研究——肥育性能和胴体评定

“七五”期间,我们承担了提高东北民(?)(简称民猪)生产力的研究任务。 1986年进行了民猪、长白猪、杜民、长(?)和长杜民猪生长肥育的试验,研究民猪、长白猪和二、三元杂种猪的肥育效果,为本课题五年研究提供基础资料,并为当前北方高寒地区开展商品瘦肉型猪生产提供科学依据。本试验研究项目,包括肥育性能、胴体评定、肌肉生长特点、肉质测定、左半胴可食部分化学组成和肌肉中氨基酸的含量。现将本试验肥育性能和胴体评定研究结果报告如下。     

以大麦作基础饲料对猪胴体及肉质的影响

选择日龄、体重相近的健康去势约×荣杂交仔猪作为试验对象,研究在日粮消化能、粗蛋白质、赖氨酸及钙磷水平相近的条件下,以大麦替代玉米作基础饲料对猪胴体性状及肉质有何影响.结果发现,①饲喂大麦型日粮猪只的胴体性状优于饲喂玉米型日粮猪只,表现在胴体瘦肉率增加(试验组53.01%,对照组50.01%,提高3.00个百分点),背膘厚度降低(6～7肋膘厚试验组3.82cm,对照组4.22cm,降低9.48%;肩、腰、荐三点均膘试验组4.03cm,对照组4.18cm,降低3.59%),但差异均未达显著性水准(P＞0.05);②在肉质方面,饲喂大麦型日粮猪只的大理石纹评分、肌肉粗脂肪含量及肌肉干物质含量均稍低于饲喂玉米型日粮猪只.大理石纹评分试验组为2.75分,对照组为3.08分(sig=0.110);肌肉粗脂肪含量试验组为2.61%,对照组为3.47%(sig.=0.281);肌肉干物质含量试验组为26.61%,对照组为27.63%(sig.=0.083).但差异均未达显著性水准(P＞0.05).     

基于解剖学的人手肌肉建模技术

为实现仿真手在运动过程中符合人手的生理特性及运动特点，文中通过分析手的解剖结构，总结控制手部运动和形状的约束参数．采用层次建模方法，先建立用线段表示的含有约束参数的手部骨骼模型，然后在此基础上根据手部的特征横截面确定特征多边形，采用NURBS面片拟合的方法建立依附于骨骼之上的肌肉模型。此方法建立的手部模型在运动仿真过程中，手部肌肉以对应的骨骼为轴线并随着骨骼各个参数的变化而发生相应的变化，最终取得良好的仿真效果。     

基于人眼多线谱的MPEG-4参数计算

提出了由人眼多线谱计算MPEG-4相关人脸动画参数(FAP)的方法.人眼多线谱利用一组随时间变化的归一化肌肉收缩量表示人眼运动及表情,通过对其采样可获得视频各帧对应的归一化肌肉收量.根据三雏肌肉控制人眼(3D-MCE)模型与MPEG-4标准模型在特征点、运动表示参数,坐标及尺度上的对应关系,可由归一化肌肉收缩量集计算相应FAP,以驱动任意基于MPEG-4标准的人眼模型.实验证明该方法所用数据量及计算量较小,所得MPEG-4参数可以驱动得到较逼真的人眼运动及表情.     

An evaluation of process-parameter and part-geometry effects on the quality of filling in micro-injection moulding

This paper addresses the use of micro-injection moulding for the fabrication of polymeric parts with microfeatures. Five separate parts with different micro-feature designs are moulded of Polymethylmethacrylate. The design-of-experiments approach is applied to correlate the quality of the parts to the processing parameters. Five processing parameters are investigated using a screening half-factorial experimentation plan to determine their possible effect on the filling quality of the moulded parts. The part mass is used as an output parameter to reflect the filling of the parts. The experiments showed that the holding pressure is the most significant processing parameter for all the different shapes. In addition, the experiments showed that the geometry of the parts plays a role in determining the significant processing parameters. For a more complex part, injection speed and mould temperature became statistically significant. A desirability function approach was successfully used to improve the filling quality of each part.     

Strengths and limitations of a musculoskeletal model for an analysis of simulated meat cutting tasks

This study assessed the capacity of a musculoskeletal model to predict the relative muscle activation changes as a function of the workbench height and the movement direction during a simulated meat cutting task. Seven subjects performed a cutting task alternating two cutting directions for 20 s at four different workbench heights. Kinematics, electromyography (EMG), and cutting force data were collected and used to drive a musculoskeletal model of the shoulder girdle. The model predicted the muscle forces exerted during the task. Both the recorded and computed activation of the muscles was then compared by means of cross-correlation and by comparison of muscle activation trends with respect to the workstation parameters, i.e. cutting direction and workbench height. The results indicated that cutting movements involving arm flexion are preferable to movement requiring internal arm rotation and abduction. The optimal bench height for meat cutting tasks should be between 20 and 30 cm below the worker's elbow height. The present study underlines a beneficial use of musculoskeletal models for adjusting workstation parameters.     

Radial textures: a new algorithm to analyze meat quality on MRI

Multimedia Tools and Applications - Magnetic Resonance Imaging (MRI) was introduced as an alternative to destructive methods for determining the quality parameters of meat products, since MRI is a...     

拟人Agent面部运动模型研究

提出一种用于人脸生理解剖的拟人Agent面部运动模型。将拟人Agent的面部分解为脸、嘴、眼、下巴、舌和头,根据面部辐射肌和口轮匝肌等肌肉的运动特点,通过肌肉变形,推导出控制面部运动的特征参数和辅助参数,由此提出多维的面部运动形式化描述方法。实验结果表明,该方法能精确控制面部的连续运动,准确描述面部表情。     

Multivariate regression modeling for monitoring quality of injection moulding components using cavity sensor technology: Application to the manufacturing of pharmaceutical device components

There is an increased demand within the moulding industry to improve the quality of moulded parts by maintaining consistent tolerances and overall dimensions. This interest is more important in areas of the moulding industry that are dedicated to pharmaceutical devices, where a quality by design approach is now expected to be adopted. A pharmaceutical device is an assembly of different plastic components which are manufactured by injection moulding; many have critical quality parameters which affect not only the device appearance but also more importantly its performance for drug delivery. Hence, the need of better understanding and control of injection moulding processes. This study presents the use of multivariate regression modeling approach to monitor the quality of the final product using cavity sensor technology (CST). The influence of the injection moulding process parameters on the quality of the final parts have been investigated using a design of experiment approach. The results demonstrate that the Partial Least Squares (PLS) regression model based on cavity pressure sensor data could be successfully used to monitor the quality (weight, dimensions) of the final product in plastic injection moulding.     

基于MATLAB的BP神经网络在猪等级评定中的应用研究*

为了客观评估猪肉各项指标和猪肉等级,采用MATLAB神经网络工具箱中的BP人工神经网络,利用猪胴体图像特征参数和活体猪图像特征参数建立BP神经网络模型。分别用猪胴体图像特征参数样本60个和活体猪图像特征参数样本80个进行了网络训练,并采用不同的BP神经网络隐含层的传递函数和隐含层神经元数量,得到 BP神经网络模型。通过仿真,将仿真结果与人工评估结果进行对比,结果表明BP人工神经网络模型可以评估猪肉各项指标和等级识别。在猪肉胴体图像特征指标下评价猪肉等级准确率达到98%,在活体猪图像特征参数评价猪肉等级准确率达到80%。说明猪肉胴体图像特征比活体猪图像特征参数更能代表猪肉质量品质也符合客观现实;同时也表明MATLAB神经网络工具箱中的BP人工神经网络可以应用在猪的等级评定中。     

Designing Synergistic Walking of a Whole-Body Humanoid Driven by Pneumatic Artificial Muscles: An Empirical Study

Our body consists of many body parts that are compliantly connected with each other by muscles and ligaments, and their behavior emerges out of the synergy of the whole-body dynamics. Such synergistic behavior generation is supposed to contribute to human adaptive movement such as walking. This paper describes designing synergistic walking of a whole-body humanoid robot whose joints are driven by artificial pneumatic muscles antagonistically. We propose to take an incremental design approach to deal with the complicated dynamics of the system. As a result, we can determine control parameters that govern whole-body behavior. We experimentally demonstrate that the humanoid walks stably with a simple limit-cycle controller.     

Predicting quality characteristics of end-milled parts based on multi-sensor integration using neural networks: individual effects of learning parameters and rules

Artificial neural networks have been shown to have a lot of potential as a means of integrating multi-sensor signals for real-time monitoring of machining processes. However, many questions still remain to be answered on how to optimize the training parameters during the training phase to optimize their subsequent performance, especially in view of the fact that the few published articles have made conflicting recommendations. This paper presents a systematic evaluation of the individual effects of training parameters — learning rate, momentum rate, number of hidden layer nodes, transfer function and learning rule-on the performance of back-propagation networks used for predicting quality characteristics of end-milled parts. Multi-sensor signatures (acoustic emission, spindle vibration, cutting force components and machining time) acquired during circular end-milling of 4140 steel and the corresponding measured quality characteristics (surface roughness and bore tolerance) were used to train the networks. The network is part of a proposed intelligent machining monitoring and diagnostic system for quality assurance of machined parts. The network performances were evaluated using four different criteria: maximum error, rms error, mean error and number of training cycles. One of the results obtained shows that the hyperbolic tangent transfer function gives a better performance than the sigmoid and sine functions respectively. Optimum combinations of training parameters have been observed. The effects of various combinations of training parameters are presented.     

Multivariate Analysis of Biomechanical Profiles for the Coracobrachialis and Biceps Brachii (Caput Breve) Muscles in Humans∗

A multivariate analysis of various biomechanical parameters for the muscles coracobrachialis and biceps brachii (caput breve) was conducted for two groups of human subjects while they practiced a skill acquisition task conducted over a period of time and at different subject-to-target distances. Practice at different distances had no effect on either muscle. Comparisons of pre- and post-test data indicated that the biomechanical parameters were altered as a function of practice or increased time spent at the task. A specific statistical comparison of these two morphologically similar muscles indicated significant differences in their response profiles. Lastly, practice had a differential effect on the activity of the two muscles.     

生物阻抗技术及其在肉品质检测中的应用

介绍了生物阻抗分析方法和生物阻抗频谱分析方法的基本理论。综述了现阶段生物阻抗技术在肉品品质检测中的应用情况和发展趋势。现有研究结果表明：通过检测肉品组织阻抗谱可以分析肉品中脂肪、水分、嫩度等品质因素,还可以辨别PSE肉。研究发现,阻抗技术应用于品质检测时将受到一些因素的影响,如,畜体屠宰后的测量时间、不同的组织和同一组织的不同测量部位与驱动电流流过组织的方向,在今后的研究中应注重这项检测技术的标准化,以减少这些因素对测量准确性的影响。