Projection center calibration by motion

Camera calibration is the first step of three-dimensional machine vision. A fundamental parameter to be calibrated is the position of the camera projection center with respect to the image plane. This paper presents a method for the computation of the projection center position using images of a translating rigid object, taken by the camera itself.

Many works have been proposed in literature to solve the calibration problem, but this method has several desirable features. The projection center position is computed directly, independently of all other camera parameters. The dimensions and position of the object used for calibration can be completely unknown.

This method is based on a geometric relation between the projection center and the focus of expansion. The use of this property enables the problem to be split into two parts. First a suitable number of focuses of expansion are computed from the images of the translating object. Then the focuses of expansion are taken as landmarks to build a spatial back triangulation problem, the solution of which gives the projection center position.     

以国标GB1.7为指导编制“变流器包装”企业标准

介绍了某企业在变流器包装的设计和制定其企业标准的过程中执行ＧＢ１．７（标准工作导则）的情况，论述了在充分考虑产品特点和流通环境条件下，企标增补的内容，这些内容是对变流器包装有关标准的深化和创新。新企标不仅注重标准深度，而且考虑标准广度方面的拓展，代表了当前较好的生产水平，可作为生产过程中控制质量，评价和检验质量的依据。     

反井钻及其在我国水电工程的应用

本文介绍了反井钻这一新型的竖井和斜井开挖施工设备，以及该设备在国内水电工程中的应用。实践证明，在适当的地质地形条件下，反井钻比人工正井法、吊罐、阿里马克爬罐法都具有明显的优越性，值得在国内其它水电工程中推广应用。     

Conceptual design of a high-efficiency absorption cooling cycle

The search for high-efficiency, gas-fired cooling cycles has led to the development of dual-loop absorption machines with cooling coefficients of performance (COPs) in the 1.2 to 1.7 range. This increased performance may call for high generator temperatures, new working fluids or new materials of construction. In most cases, two different sets of working fluids are required. The conceptual design presented here is aimed at obtaining high efficiencies with relatively low temperatures, employing only one set of fluids. The concept consists of two loops coupled in a configuration aimed at minimizing the loss of thermodynamic availability incurred when transferring refrigerant between the loops. The working fluid pair is a solution of lithium bromide-water. The calculated COPs are of the order of 1.8. The cycle relies on an elaborate evaporator-absorber combination. The paper presents the conceptual design, the critical assumptions, and the performance calculations for the concept.     

Membrane Packaging System to Permit Safe Hydration of Freeze-Dried Contents with Impure Water

We tested the feasibility of using polymer membranes for a self-hydrating packaging system to reconstitute freeze-dried foods using nonpurified water. Several commercial membranes were screened according to (1) hydration rate, (2) water permeability, (3) passage of microorganisms, (4) salt rejection, and (5) strength. The most promising membranes were used for developing and testing prototype packaging systems. A feasible self-contained rehydration system was a nylon-6 polyamide membrane that rehydrated the freeze-dried food within 30 min while passage of microorganisms was prevented. The temperature was 37°C, and the food contained 0.5g/5g of a low molecular weight solute (salt). Such self-contained membrane rehydration systems must be designed to accommodate expected environmental conditions such as temperature, relative humidity, and nature of the product.     

Application of Laminated Edible Films to Potato Chip Packaging

The effects of various stearic-palmitic acid blend concentrations in films, storage temperatures and storage times on potato chip quality were evaluated using Response Surface Methodology. Storage temperature and time affected the quality of potato chips. The maximum storage times for acceptable potato chip quality were: 30 to 43 days, 23 to 25 days, and 11 to 12 days for storage temperatures of 15, 25 and 35°C, respectively. Results were independent of stearic-palmitic acid blend concentrations.     

CETRAN系统中的英语词汇结构与功能

本文介绍了汉英机器翻译系统中从中间媒介语言生成英语的生成系统的词汇结构和功能，描述了生成系统各个层次之间的转换原理。为了说明清楚，在叙述中注意了列举从中间媒介中间媒介语言到目标语句的生成实例。     

玻璃包装改进及经济效益分析

论述了平板玻璃包装技术改进对提高包装质量和企业经济效益的影响,介绍了平板玻璃包装箱(架)的性能,简述了计算机辅助设计及计算机辅助管理在玻璃包装结构设计及包装质量管理中的效用。     

Reverse reachability analysis: A new technique for deadlock detection on communicating finite state machines

The communicating finite state machines can exchange messages over bounded FIFO channels. In this paper, a new technique, called reverse reachability analysis, is proposed to detect deadlocks on the communication between the communicating finite state machines. The technique is based on finding reverse reachable paths starting from possible deadlock states. If a reverse reachable path can reach the initial global state, then deadlock occurs. Otherwise the communication is deadlock-free. The effectiveness of the technique has been verified by some real protocols such as a specification of X.25 call establishment/clear protocol and Bartlet's alternating bit protocol.