基于图像的原木去弯截断方法

为了提高小径级原木的出材率,需要对原木进行去弯截断处理,为此设计了原木图像检测与去弯截断系统.分析了原木图像处理流程,研究了基于最大类间方差法的原木图像分割方法,并对分割后的原木图像进行了形态学滤波.在此基础上,采用边缘检测方法实现了原木图像中心线提取,给出了基于中心线的原木自动去弯截断方法.试验结果验证了原木图像处理方法的有效性.     

The effect of saw kerf width on the value of the axial growth stress measured by slitting a log along its axis

The surface growth stress in logs can be determined by slitting the log axially and measuring the outward deflection of the two halves. The saw kerf removes stressed material which generates a compressive strain in the remaining material and thereby reduces the surface growth stress. The purpose of the work is to establish the magnitude of this error. The analysis assumes a uniform compressive stress in the core of the log and a logarithmic distribution in the outer region. The total axial force in the kerf before removal is calculated and, from this, the stress change in the material remaining after kerf removal is derived. Data are presented for a range of kerf widths and for three different growth stress distributions. Direct measurement of the kerf removal error was made by direct measurement of the contraction of the log and by strain gauges to measure the strain. The measured values were close to the calculated values for three growth stress distributions. The analysis yields acceptable values for the kerf removal error. The investigation concludes that for kerf widths not greater than one-tenth of the log diameter, the error in the measured tensile surface growth stress is less than 10%.     

不同干燥条件下小径桦木材性指标的研究

对小径桦木在大气及干燥室等不同条件下干燥后的材性进行了测试，结果表明：不同干燥条件对小径桦木的材性有影响。室干材的尺寸稳定性、变形程度及力学性能均优于气干材；采用软干燥基准时，可改善小径木的尺寸稳定性和力学性能，从而提高干燥质量。从总体材性指标可见，小径木更适合室内干燥。     

提高人工长白落叶松原木出材量设计精度的探讨

针对所设计的采伐作业小班。对人工长白落叶松样木进行原木出材率测算。在“吉林省森林采伐更新造林设计系统”微机软件内上调出材率。提高原木出材量的精度。     

基于Android的综合公园养护日志管理系统研究

养护日志编写是综合公园管理的重要日常工作之一,文章基于Android移动终端平台,分析了综合公园养护日志管理应用于移动终端的功能需求及原则,提出并设计了能在本地及移动互联网环境下进行实时编写、报告、查询、规则展现的综合公园养护日志管理系统。     

Forests to buildings: A geography of log home manufacturing

The article presents a material-geographic study of contemporary log home manufacturing in the Eastern Woodlands of North America. The study investigated relationships between log conversion (i.e., processing) methods and regional location. Manufacturers were grouped by their conversion methods, using hierarchical cluster analysis; and analyzed for spatial correlation, using standard deviational ellipses (SDEs). Tree species utilization, log treatment, horizontal surface type, and corner notch type were found to be spatially differentiating. These attributes were tested for their ability to predict manufacturers’ culture region using multinomial logistic regression (MLR) models. Tree species utilization was an independent variable in all of the predictive models, suggesting a correspondence between building culture and ecological regions. This is consistent with earlier research. The findings suggest that location drives tree species utilization and, thereby, building methods. Like the eco-region itself, log conversion methods vary on a north-south gradient. It is argued that construction knowledge is geo-contextual and that the replacement of scientific wood extraction with ecosystem management as the central paradigm in forestry calls for geo-contextual approaches to sustainability in the construction industry.     

浅析木材加工剩余物的利用途径

木材是天然可再生资源,并且在社会中得到了广泛的应用。我国是木质材料生产、加工和消费大国,供需矛盾突出。笔者概述了木材加工剩余物利用的必要性,并简述了木材加工剩余物在生物质燃料、林产工业,以及新型复合材料等方面的应用,为企业充分利用木材加工剩余物开发新的加工途径,提高木材利用率,缓解木材的使用压力提供启示。     

我国杨树人工林材性与加工利用研究现状及发展趋势

本文概述了杨树人工林发展概况,全面分析了杨树人工林木材性质与加工利用研究现状和存在问题,指出将杨树人工林材性与加工利用结合起来进行研究是合理、高效利用杨树人工林木材的必由之路。     

The effect of rotation speed on the power consumption and cutting accuracy of guided circular saw: Experimental measurement and analysis of saw critical and flutter speeds

ABSTRACT

This paper investigates the effect of rotation speed and vibration response of a circular saw on the sawing process of Douglas-fir wood. An idling test was conducted on a guided circular saw to determine its stable operation speeds and vibration behavior. Short-time Fourier transform analysis was performed on saw idling test data, and variation of excited frequencies of the blade as a function of rotation speed was obtained. The saw blade critical speeds and the rotation speeds that correspond to saw flutter instability were identified. Then experimental cutting tests were conducted at different cutting conditions and the effect of rotation speed and saw vibration response on cutting power consumption and sawing accuracy was investigated. The results showed that conducting a saw idling test and vibration response analysis can identify the saw critical and flutter speeds, which is essential for identifying the optimum rotation speed of circular saw. There was a significant increase in power consumption when cutting at super-critical and super-flutter speed. The effect of rotation speed on sawing accuracy is complex and nonlinear. This effect interacts with feed speed, which makes it difficult to generalize sawing accuracy versus rotation speed in the circular sawing process.     

速生小径材在家具上的开发应用

论述了速生小径材在家具上的主要应用途径及其剖方，干燥，胶合轩等加工工艺。     

浅谈伐区设计出材和实际出材差值产生的原因和解决办法

本文针对森工企业伐区设计出材和实际出材存在的差值 ,通过调查和核查等手段 ,找出了问题存在的原因和解决办法     

落叶松木材细胞胞壁厚度数学模型的研究

以黑龙江省帽儿山的落叶松为试材,利用显微镜测定年轮内细胞胞壁厚度从早材到晚材的变化数据,对其生长变化进行研究归纳。通过对数据的函数拟合得出:年轮内胞壁厚度从早材到晚材呈指数变化趋势,由此得出胞壁厚度的数学模型。此研究对于了解落叶松生长机理方面以及对落叶松材性预测方面的研究工作,将有一定的借鉴和帮助。     

Estimating Scots pine (Pinus sylvestris L.) log diameter under bark by using shape and image data

The sawmilling industry stores and measures logs in bark in order to maximize efficiency, quality conservation and preservation. However, billing is based on the diameter under bark, which it is necessary to estimate based on manual or automatic bark detection. Recently, an approach for automatic determination of diameter under bark based on a multi-sensor approach, including shape data, colour image data and tracheid effect data has been presented, including promising results for logs of the species Norway spruce (Picea abies (L.) H. Karst) and Silver fir (Abies alba Mill.). This paper extends this approach to Scots pine (Pinus sylvestris L.). The comparison of the estimated diameters under bark of 270 pine logs with the respective diameters after debarking shows that the method works well and reliably. Estimation errors are in general close to zero and are below ±10?mm for 98% of the logs. In comparison with manual bark detection, the automatic approach is clearly an improvement. Influences of season or characteristics like discolouration are mostly small. Applying a bark detection algorithm trained on spruce to the pine logs leads to acceptable results, but using a separate algorithm for pine leads to an even better performance.     

利用Radon函数变换对木材纹理方向自动检测的研究(英文)

本文提出一种利用计算机自动检测木材纹理方向的新方法。四种Matlab 图像变换函数被尝试用于木材纹理形状的检测。通过比较发现BWMORPH 是最适于检测木材这类中弱纹理的函数,并提取生成了木材纹理骨骼线图像;再对木材纹理骨骼线图像进行Radon变换,得到0°~180°范围内每一角度上的纹理线在投影变换域的积分值,并绘制出纹理线积分值随角度变化的二维曲线图以反映木材纹理角度上的变化规律。进而分析了国内40 个树种的纹理方向曲线图以及它们以针叶、阔叶树材和径向、弦向切面作区别的分类统计规律。结果显示,根据Radon 变换图及其纹理曲线图所反映的木材纹理的方向性规律与人们平常对木材纹理的印象相吻合。这也证明了此种新方法的有效性以及它的应用潜力。图7参6。     

MATLAB在木材内部缺陷检测图像处理中的应用

应用MATLAB软件,对检测到的木材内部缺陷二维图像进行图像增强和图像边缘检测研究。结果表明,利用MATLAB软件的图像处理功能,有助于提高木材内部缺陷检测的分辨能力。     

基于Solidworks的原木吊装桥式起重机桥架结构研究

原木吊装桥式起重机是林业生产过程中木材堆场的重要起重机械,而对其结构进行分析和评定是原木吊装起重机林业生产过程中重要的一环。利用Solidworks软件完成某型桥式起重机桥架结构的三维建模,通过Solidworks Simulation插件对桥式起重机受力情况进行了有限元仿真分析,得到了桥架结构的应力和位移云图,且仿真结果和一般传统力学解析计算所得结果相同。结果表明:基于Solidworks软件的三维有限元分析,可以快速可靠地得到原木吊装桥式起重机桥架结构受力变化结果,为快速分析此类林业机械结构,评定结构方案是否合理提供了方法。     

Locating and identifying splits and holes on sugi by the laser displacement sensor

The split and the hole are two common defects on sugi (Cryptomeria japonica D.Don). They have a common feature in that they are associated with surface irregularities. We have developed a laser scanning system to detect the splits and the holes based on their thickness, which correlates spatially with the profile information. The displacements measured by the laser sensor were converted to pixel values to generate the displacement profile image. Both the splits and the holes manifested well in the image. A dedicated image-processing program written in Visual Basic has been developed. The defects regions were accurately located by the image processing. To identify the defects, eight recognition rules based on four features have been utilized. Furthermore, a method based on the pixel model was proposed to compute the area of the defect. The results indicated that the defects could be identified correctly, and the areas could be computed accurately using the pixels model.     

木材标准中有关术语的解析

本文对木材标准中树种、检尺长、检尺径、检尺长范围内（外）、全材长术语进行了明确阐述，意在消除矛盾与纠纷，使木材标准化工作有效、顺利的开展。     

干燥条件对小径桦木干缩性能的影响

根据在大气及干燥室等不同干燥条件下的试验，探讨了小径桦木干缩性能的变化规律。为合理选择和制定小径桦木干燥基冷提供理论依据。     

Effect of log position in European Larch (Larix decidua Mill.) tree on the technological properties of particleboard

The impact of log position in European Larch (Larix decidua Mill.) tree on the physical, mechanical, and surface properties of the particleboard was investigated. The logs were divided into five segments from the butt to the top of tree, which were 0–3 m, 3–6 m, 6–9 m, 9–12 m, and 12–15 m, respectively. The fiber length and wall thickness of the wood decreased with the increase in the tree height while the lumen diameter decreased. Similarly, the amount of cellulose and lignin decreased with the increase in tree height while the amount of hemicelluloses increased. The highest solubility values (hot and cold water, NaOH, and alcohol-benzene) and pH of the wood were found in the butt log, followed by the middle log, and top log, respectively. The physical (thickness swelling, water absorption) and mechanical properties (modulus of rupture, modulus of elasticity, and internal bond), and surface quality (surface roughness and contact angle) of the particleboards were negatively affected by increasing tree height. The best properties were obtained for the particleboards produced from the particles of the butt log (0–3 m).