The four-line model of the Triangular Running Skyline system: Scale model test

The four-line model of the Triangular Running Skyline (TRS) system is the theory generalized from the previous TRS theory to treat the main and slack-pulling lines separately. The previous theory,i.e., the three-line model, treated the main and slack-pulling lines as a single line to simplify the solution. The first part of this study developed numerical procedures for the four-line model. In this paper, to empirically ascertain the accuracy of the four-line model theory, a series of static equilibrium tests was carried out using a reduced scale model of the TRS system. The result proved that the theory of the four-line model has the same accuracy as that of the three-line model. However, the result also proved that the carriage may have to be located lower than the designated height. Thus, it has been proved that the development of a certain adjusting method is necessary to move the carriage of the TRS system closer to the designated point. A part of this paper was orally presented at the Second Annual Meeting of the Japanese Forest Engineering Association, November 18, 1995, Tokyo. This English title is a tentative translation from the original Japanese by the authors of this paper.     

MECHANICAL ANALYSIS OF TREE SPARS IN CABLE YARDING SYSTEMS

Tree spars,as appropriate supports for cable yarding systems,have to beverified for the strength before any real operation.This paper gives theoretical analysisfor various cases.Tree spars without guylines are normally under heavy bending stress,which dominates the strength design.For tree spars equipped with guylines,the spardeflection follows the same way as an unguyed spar.The overload of the bending stressremains the main reason of spar failures.Several diversities of tree spars from theidealized condition are investigated for the sake of better modeling of the real situation.Analysis supports that the tree spar can generally be treated as a straight cylindricalcolumn without giving significant errors.The load can be handled as centrically applied.Design methods are provided for both guyed and unguyed tree spars,which will benefit thepractice of using tree spars as an alternative for steel spars.     

YP1.0-A遥控跑车及其遥控系统设计

YP1.0-A是我国第三代全自动遥控跑车,具有利用液压制动取代半自动跑车在索道线路中的止动器,具有在索道沿线任意点停留、自动起落钩的优越性。通过对YP1.0-A遥控跑车主要技术参数、结构及其工作原理进行系统分析,对遥控系统进行设计,包括电源、遥控电路、发射与接收控制等,提高了遥控系统的灵敏度、精确度和简便性,更有利于实现遥控跑车在工程应用中生产安全和联合作业,提高遥控索道的生产效率。     

The ability of a carriages developed for a mobile tower yarder: A comparison of the hauling force and walking time in a line pulling out process

The ability of a newly developed carriage equipped with a remote control lock and self line extraction system manufactured by Oikawa motors Co., Ltd. was analyzed. The study investigated the reduction of the work load of the choker setter in the haul line-pulling out process of a cable logging system by a mobile tower yarder. The main objective was to compare the walking time, pulling out time, and the tension force using the three types of cable setting method, a running skyline with a simple carriage, a fixed skyline with a simple carriage and a fixed skyline with a newly developed carriage. The measuring of haul line pulling out was conducted on different slope gradients at different distances from the tower spar by four choker setters. The study showed that choker setters could reduce the force exerted by about 33%, and a decrease in the heart beat rate of 12%, when using the fixed skyline with the newly developed carriage as opposed to the running skyline with the simple carriage. The fixed skyline with the newly developed carriage resulted in more pulling speed than the running skyline with the simple carriage on the slope gradient of over 2° and the fixed skyline with simple carriage on the slope gradient of over 7°. With the newly developed carriage the pulling tension, time and heart rate are lower, when the haul line is pulled out. Thus it can be concluded that the new carriage is more productive than the simple carriage in the line pulling out process.     

Japanese forest sector modeling through a partial equilibrium market model

The structure of Japanese timber markets has changed drastically during recent decades. After the introduction of a large amount of imported softwood products. Japanese timber producers have faced global competition with foreign timber suppliers such as Canada, the US, and recently Nordic countries. In this paper, we present a forest sector model for lumber markets with a focus on eight aggregate regions (Tohoku, Kanto, Hokuriku, Chubu, Kinki, Chugoku, Shikoku, and Kyushu) in Japan. The proposed model is based on the Samuelson-partial equilibrium formulation, which searches for an optimal solution by maximizing the net social payoff subject to demand and supply constraints. A nonlinear programming solution technique is incorporated into the proposed model. Three types of lumber are considered,i.e., domestic lumber, the lumber processed in Japan from imported logs, and imported lumber from the US and Canada. Using data for 1998, our analysis indicates that the derived equilibrium solution has a higher price for the imported lumber supply in all regions, and a lower price for the other two products in most regions than the actual current price in 1998. The derived net social payoff gains 1.6% compared with the one derived with the current set of prices and quantities. This is research was supported by the Grant-in-Aid for scientific Research (No.11691090) from the Ministry of Education, Culture, Science, Sports, and Technology of Japan.     

论日本诗话中的复古理论

复古理论是中国古代诗学批评的一大主要论题,它在日本诗话中也受到了相当的关注。本文从格调论、性情论二个方面论述了日本诗话中的复古理论,并探寻了其文化和理论渊源。     

Effective sampling method for estimating bending strength distribution of Japanese larch square-sawn timber

Information on the strength distribution of timbers and other wood products seems to have become more important for users and producers after revision of the Japan architectural standard in 1998, which emphasizes the performance requirements of structures. Because there is no way other than expensive destructive tests to collect strength data, many researchers have proposed many inspecting methods for predicting strength by nondestructive evaluation. The most popular method for structural timber is the mechanical grading method based on the relation between Young's modulus (E) and strength () with some linear regression models. On the other hand, it is well known that the proof loading test is superior for obtaining information on the lower tail of distribution. If the E distribution of the objective timbers is known approximately, selecting timbers nearest to the projected E values saves timbers for destructive tests. We examined the alternative sampling method using the reported e- data sets of Japanese larch square-sawn timber. The simulated results showed that the estimated lower tail of the bending strength distribution by the alternative method was a better approximation of the experimental distribution than that derived from the conventional linear regression model.Part of this paper was presented at the 47th Annual Meeting of the Japan Wood Research Society, Kochi, April 1997     

长螺旋钻机液压动力头箱体静动力学分析

动力头箱体是动力头系统重要的承载部件,其力学性能关系到动力头系统的正常运转和钻孔质量。本文运用CAE软件建立长螺旋钻机液压动力头箱体的三维实体模型并对其进行有限元静力学分析,通过分析发现箱体在强度和刚度上的薄弱之处并对其进行合理的强化改进;对改进模型进行动力学模态分析,得出箱体前六阶固有频率并探讨动力头箱体与其他相邻部件发生共振的可能性,提出避免动力头系统工作发生共振的措施,为钻机动力头箱体设计提供可供参考的设计分析方法。     

综合布线系统工程桥架和槽道的安装

随着建筑智能化的发展,综合布线系统是各种控制系统的载体,除合理设计外,施工安装是十分重要阶段;本文着重从施工安装角度,较全面地阐述了该阶段应注意的诸多实际问题。     

Mechanisms of perception of laid lines in Japanese paper

Laid lines are observed frequently in Japanese paper. For restoration of historic document paper, the laid line intervals should be consistent between the restoration paper and the original paper for harmonized appearance. Considering this prerequisite, the perception mechanisms of the laid lines are discussed. Laid lines can be easily observed against backlight. However, there are several cases where laid lines are not visible against backlight, but are clearly visible with diffuse reflected light. With paper sheets formed on screens with short bamboo splint pitches, laid lines were observed only with diffuse reflected light. Within these sheets, there was no fiber mass distribution or surface roughness that correlated with the periodicity of the laid lines. On the other hand, paper sheets produced using long splint pitches exhibited light transmission unevenness, fiber mass unevenness, and surface roughness. Microscopic observations using two-way low-angle illumination revealed the following mechanism. In the flow sheet-forming method, fibers are oriented strongly in the cross-splint direction in the first layer while some fibers rotate and become aligned along the interspaces between the splints in the second layer during dehydration. Bidirectionally oriented fibers perpendicular to each other result in a contrasting reflectivity perceived as laid lines.     

Use of GIS-derived environmental factors in predicting site indices in Japanese larch plantations in Hokkaido

The objectives of this study were (1) to evaluate the effects of environmental factors derived from GIS on tree-height growth of Japanese larch (Larix kaempferi) and (2) to develop a best-fit regression model for its site index. Based on data from 40 sample plots situated in an even-aged (38 years), pure, and undamaged Japanese larch stand, multiple regression models for a site index of Japanese larch were constructed using environmental factors as independent variables. The average slope gradient, effective relief, distance from ridge, flow accumulation, degree of exposure, shading, solar radiation index, and gravitational water index were used as environmental factors and calculated on GIS using digital elevation model data. These factors were related to the Japanese larch site index through multiple-regression analysis. The result showed that the most effective factor for estimating site index was the degree of exposure. Through a backward stepwise procedure, the degree of exposure, shading, and average slope gradient were selected for a best-fit regression model. This model explained 72% of the variance in site index, with standard error estimates of 1.75 m. This strong relationship suggests that GIS-derived environmental factors can be used to predict site indices of Japanese larch. This study was supported by the experimental forest of Kyushu University.     

利用辽宁省森林生态网络构筑生态防火网络体系的思考

立足辽宁省森林生态网络体系的"点(中心城镇)"、"线(河流线、海岸线、铁路线、公路线、防护林带)"、"面(主要林区)"系统,综合考虑各地的自然、经济条件、林分状况、火险等级等实际,探讨利用河流、山脊、沟壑等自然条件和林道网、防护林带等森林生态网络元素构筑完整的封闭式生态防火网络体系.文中具体阐述了生态防火网络的设计原则与框架,提出加强领导,落实责任,依靠科技,提高水平,强化管理,完善政策等生态防火网络建设的保障措施.     

Measurement of the shear modulus of wood by asymmetric four-point bending tests

We conducted asymmetric four-point bending tests of wood and obtained the shear moduli on the basis of Timoshenko's theory of bending. Akamatsu (Japanese red pine,Pinus densiflora D. Don) and shioji (Japanese ash,Fraxinus spaethiana Lingelsh.) were used for the tests. Asymmetric four-point bending tests were undertaken by varying the depth/span ratios; and Young's modulus and the shear modulus were calculated by Timoshenko's bending theory. Independent of the asymmetric bending tests, we also conducted three-point bending tests, free-freeflexural vibration tests, and numerical calculations by the finite element method. Young's and shear moduli obtained by these methods were compared with those derived from the asymmetric bending tests. Based on these comparisons, we concluded that the shear modulus can be properly obtained by the asymmetric four-point bending tests when the span is 20 times larger than the depth.     

基于压缩感知SAMP算法的改进

压缩感知是近年来兴起的以较大压缩比率并且能够以较好的效果恢复原始信号的一种新型理论。本文针对SAMP算法在重构精度相对较差以及运算时间较长的问题,提出一种新的SAMP改进算法。该算法首先将稀疏信号进行分块后再重构,其次在重构算法过程中开始对信号稀疏度进行初始估计,然后采取变步长增加稀疏度的方法逐步求出原始信号的最优估计值。理论分析和实验表明,改进后的算法减少运算时间,提高重构精度,增进实际使用价值。     

集体林权制度改革探析

在论述集体林权制度改革的历史沿革、林权制度对发展的制约等背景的基础上,阐明了进行林权制度改革的重要性和必要性.认为集体林权制度改革必须坚持农村土地基本经营制度,确立农民的经营主体地位,明晰林地使用权和林木所有权,放活经营权.改革的目标是:山有其主,主有其权,权有其责,责有其利.改革的主要内容是:明晰产权、放活经营、减轻税费、规范流转、综合配套.     

ZDTB-L1型智能贴标机系统设计与模型分析

针对某生产线使用的旧式贴标机控制系统存在的问题,通过对贴标运动进行数学分析,建立运动模型,并在此基础上设计出ZDTB-L1型智能贴标机系统,该系统完全满足整个生产线对贴标机的技术要求.     

A model for the relationship between form-factors for stem volume and those for stem surface area in coniferous species

A model that describes the relationship between the form-factors for stem volume and those for stem surface area in coniferous species is proposed. The model is derived assuming that the stem form of a tree can be expressed by Kunze's equation. The model indicated that the form-factor for stem surface area was directly proportional to the square root of the form-factor for stem surface volume, independent of the stem position. The proposed model expressed the relationship of the form-factors for Japanese cedar (Cryptomeria japonica D. Don) and Japanese cypress (Chamaecyparis obtusa Endl.) trees well. Therefore, the form-factors for stem surface area could be estimated from those for stem volume. No significant difference in the coefficient was found between Japanese cedar and Japanese cypress trees, indicating that the proportional coefficient would be common between the two species. Many studies have shown that the form-factors for stem volume at 0.7 and 0.5 in relative height were, respectively, almost steady at 0.7 and 1.0, independent of species, district, density control, and growth stage. Substituting these universal values into the proposed model, the form-factors for stem surface area at 0.7 and 0.5 in relative height were estimated to be 0.730 and 0.873, respectively. The estimated values of the form-factors for stem surface area would be universal for coniferous species. The proposed model also showed that the breast height form-factor for stem surface area decreased sharply with the increase in total tree height, when the height was less than 10 m. However, after the tree attained the total height of 10 m, the breast height form-factor gradually decreased with the total tree height approaching its asymptotic value of 0.605. In conclusion, the model proposed here can be used to describe the relationship between form-factors for stem volume and those for stem surface area successfully.     

基于六点定心理论的原木端面计算机视频定心检测理论应用研究

在旋切智能上木定心机器人实验台的定心作业过程中 ,定心数据采集主要包括原木四个截面、两种方式的定心处理 ,其中原木两端面的定心数据采集采用计算机视频检测方法。本文依据旋切原木六点定心理论 ,建立了原木端面视频数据采集的数学模型 ,满足了两端面的定心精度要求 ,同时分析了该理论的应用领域     

移动智能体在森林病虫害专家系统中的应用研究

介绍智能体和移动智能体的发展及其技术理论。通过对移动智能体技术的分析,利用其移动性、能动性和交互性强的特点,提出将其应用到森林病虫害专家系统中,构建基于移动智能体的森林病虫害专家系统,进而提高专家系统的智能性,并对此系统的主要功能模块结构及其运行流程作了详细地阐述,对系统的发展前景作了展望。