A comparison of distribution and composition of intramuscular fat in Duroc Jersey and Hampshire pigs at 100 kg liveweight

The intramuscular fat content, its fatty acid composition and that from the triglyceride fraction, were determined in several muscles from the right sides of four Duroc Jersey and four Hampshire castrated male pigs slaughtered at 100 kg liveweight. The Hampshires had heavier muscles than the Duroc Jersey pigs, but did not show significant differences in the percentages of intramuscular fat. The concentrations of linoleic acid were, in general, higher in the Hampshire than in the Duroc Jersey pigs and in many muscles the differences were highly significant (p < 0·05) The concentrations of linoleic acid (18:2) in the triglyceride fraction did not differ among muscles within breeds but were higher in Hampshire than in Duroc Jersey pigs.     

Degradation of Leaf Litter Phenolics by Aquatic and Terrestrial Isopods

To investigate species-specific decomposition rates of litter from native (Quercus faginea) and introduced (Eucalyptus globulus) tree species in Portugal, we monitored changes in the phenolic signature of leaf litter during decomposition as mediated by an aquatic, Proasellus coxalis (Isopoda: Asellota), and two terrestrial, Porcellio dispar and Eluma caelatum (Isopoda: Oniscidea), detritivores. Although the litter of Eucalyptus and Quercus did not differ in overall protein precipitation capacity, we detected differences in terms of contents of particular phenolic compounds and phenol oxidation products. Accordingly, we observed food-specific consumption rates in Proasellus, but not in the terrestrial isopods. Proasellus digested Eucalyptus at significantly higher rates than Quercus, whereas the opposite was the case for Eluma, and Porcellio digested both litter types equally well. Despite slight differences in detail, effects of Proasellus on changes in the signature of litter phenolics were similar for both litter types, whereas terrestrial isopods—Porcellio and Eluma, although they differed from each other—digestively degraded phenolic compounds in Eucalyptus and Quercus litter, respectively, in different ways. Overall, however, degradation of litter phenolics was similarly effective on both litter types. From these data, we conclude that decomposition of Eucalyptus litter does not proceed more slowly than of litter from native Portuguese trees.     

一种多参数优化的联合信源信道编码方法*

针对JPEG2000码流的渐进传输特性,提出了一种多参数优化的联合信源信道编码方法,即MPO-JSCC。在码率分配的基础上,动态地选择Turbo码交织长度、迭代译码次数,通过优化编码器多个参数更好地执行不等差错保护策略,同时加入JPEG2000容错工具,在接收端利用错误掩藏机制以提高图像解码成功率。将该方法应用于噪声信道的图像传输系统中,仿真结果表明,MPO-JSCC既能在不增加系统复杂度及延迟时间的同时提高重建图像的质量,又能节省系统发射功率,具有一定的现实指导意义。     

基于Cosserat理论的头发动态模拟*

针对基于弹性杆理论的超螺旋模型中对动力学方程的求解影响头发模拟实时性的问题,采用Cosserat弹性杆理论对头发建模,引入角速度变量,并加入头发运动平衡的固有约束,得到改进的拉格朗日动力学运动方程;然后,将头发单体离散化,用角速度和四元数作为状态变量简化动力学方程,用半显式的欧拉方程加速方程的执行,大大降低了系统的运行时间,提高了模拟的速度,在满足实时性要求的同时提高了头发模拟的真实度。     

基于生物加密的认证机制

为克服传统认证技术在保护安全和隐私方面的不足,提出了一种基于生物加密的身份认证模型。运用生物加密技术对用户脸部特征和密钥进行保护,防止非授权用户的访问和非授权资源的使用。实验结果表明,尽管人的面部表情变化多端,基于生物加密技术的认证系统仍能正确区分真正的用户与仿冒用户,起到很好的认证效果,保证了安全通信。     

盲环境下数字图像的自动修复算法研究*

当前所有的数字图像修复算法都是一种半自动的方法,因为在对图像修复前,都是由用户给出想要修复的区域,而算法无法自动获取照片的破损所在。提出了盲环境下图像自动修复的概念,以基于数字图像的样本修复为基础,改进了基于纹理合成的图像修复算法。首次运用数字图像可信性评估体系于图像修复,并通过可信性综合度量模型判断确定待修复区域。实验证明,该算法最终达到了盲环境下的图像自动修复效果。     

一种有效的复杂地质体剖面图自动生成方法*

提出了一种基于平面隐函数的实体切割思想和区域自动识别技术的地质体剖面图生成方法。其主要步骤包括：采用平面隐函数实现平面和地质实体的求交运算,生成离散的交线;采用基于KD树的空间索引方法,确定交线的邻接关系,生成地质体轮廓线;封闭的轮廓线将平面划分为多个复杂的区域(内含孔、岛),采用图论的多叉树形式化表达区域存储和组织;最后对多叉树表示的区域进行矢量图案的填充。实验结果表明,该算法有较好的计算效率,是一种比较实用的地质体剖切方法。     

Fuzzing技术的样本数据组合研究*

提出了基于样本数据组合的Fuzzing技术,并抽象出了解决样本数据覆盖问题（data sample covering problem,DSCP）的数学模型;为了更好地解决样本数据覆盖问题,提出了改进遗传算法(developed genetic algorithm,DGA),通过实例实验说明了DGA的有效性,并且通过仿真实验,验证了算法在求解复杂协议文件样本数据覆盖问题时比贪心算法和简单遗传算法具有更高的效率。     

基于广义Beta函数的图像自适应增强方法*

针对传统Beta函数的图像增强方法应用于较暗区域、较亮区域,以及两端区域拉伸与中间压缩图像增强中的不足,引入增强算子和新的形状控制参数,提出了新的直方图变换函数,即广义Beta函数.在此基础上,给出了广义Beta函数增强算子选择机制,并建立了新形状控制参数的自适应选取模型.实验结果表明,提出的基于广义Beta函数的图像增强方法不仅增强了图像的对比度,而且保留了较多的图像细节信息,增强结果明显优于传统Beta函数.     

一种基于Multiway cut的多对象图像分割*

多对象分割是图像处理中的一个难题,基于Multiway cut的图像分割是一种人工交互式多对象分割方法,能够实现图像的粗分割和精确分割。使用分水岭分割图像,把图像分割为属性相似的小区域;根据交互建立节点层次图,构建带权无向网络;不同层次的节点参与不同的运算,采用Multiway cut迭代分割;交互和分割可以多次执行,直至满足用户的要求。实验结果表明,该方法人工参与方便,准确度得到提高,速度满足现场操作的要求。