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    Method and apparatus for the functional verification of digital electronic systems
    4.
    发明授权
    Method and apparatus for the functional verification of digital electronic systems 失效
    数字电子系统功能验证的方法和装置

    公开(公告)号：US5995915A

    公开(公告)日：1999-11-30

    申请号：US790460

    申请日：1997-01-29

    申请人： David F. Reed ,  Adnan A. Hamid

    发明人： David F. Reed ,  Adnan A. Hamid

    IPC分类号： G01R31/3183 ,  G01R31/28

    CPC分类号： G01R31/318314 ,  G01R31/318307

    摘要： A method and apparatus capable of generating and executing large numbers of functional tests for complex digital electronic systems at low cost are presented. The apparatus includes a test generator which uses a decision tree representation of a verification space, derived from a functional specification of the digital electronic system, to generate functional tests. A decision tree representation of a verification space includes an initial goal node, a leaf goal node, and at least one intermediate goal node interconnected by a plurality of directed decision arcs formed between the initial goal node and the leaf goal node. Goal plans assigned to goal nodes include operations which generate functional tests. Functional tests are generated by recursively "walking" the decision tree, the choices of which goal node to visit next being made at random and according to decision weights assigned to each goal node. The decision weights assigned to each goal node in the decision tree may be adjusted to ensure all portions of the verification space are adequately tested. A testing system issues functional tests to both a golden device and a device under test. The testing system compares expected responses from the golden unit to responses from device under test and produces functional test results. Specialized structures called monitors ensure sets of functional tests (i.e., functional test suites) exercise all parts of a system implementation.

    摘要翻译： 提出了能够以低成本为复杂数字电子系统生成和执行大量功能测试的方法和装置。 该装置包括测试发生器，其使用从数字电子系统的功能规范导出的验证空间的决策树表示，以产生功能测试。 验证空间的决策树表示包括初始目标节点，叶目标节点和由初始目标节点和叶目标节点之间形成的多个定向决策弧互连的至少一个中间目标节点。 分配给目标节点的目标计划包括生成功能测试的操作。 功能测试是通过递归地“走”决策树生成的，随后根据分配给每个目标节点的决策权重，随机选择要访问的目标节点的选择。 可以调整分配给决策树中每个目标节点的决策权重，以确保验证空间的所有部分得到充分测试。 测试系统向黄金设备和被测设备发出功能测试。 测试系统将来自黄金单位的预期响应与被测器件的响应进行比较，并产生功能测试结果。 称为监视器的专用结构确保功能测试（即，功能测试套件）运行系统实施的所有部分。

    Jam-resistant lead feed mechanism for mechanical pencil
    5.
    发明授权
    Jam-resistant lead feed mechanism for mechanical pencil 失效
    用于自动铅笔的阻塞引线进给机构

    公开(公告)号：US4141663A

    公开(公告)日：1979-02-27

    申请号：US774939

    申请日：1977-03-07

    申请人： David F. Reed

    发明人： David F. Reed

    IPC分类号： B43K21/08 ,  B43K24/06

    CPC分类号： B43K21/08

    摘要： An improved, jam-resistant, relatively low cost pencil mechanism is provided which includes an annular resilient member disposed about the nose bushing of the mechanism for securely locking the bushing and lead guide connected thereto in place within the pencil barrel, while at the same time allowing the pencil tip and lead guide to be threadably interconnected without creating open thread discontinuities along the length of the lead path. The resilient member serves to take up any dimensional irregularities in the pencil mechanism components and allow full threaded interlocking of the pencil tip and lead guide so that no exposed threads are present along the lead path, which can cause jamming of the mechanism if the pencil lead becomes broken within the guide. In preferred forms, the resilient member is of annular, tapered configuration permitting telescopic positioning thereof within the pencil barrel without disruption or axial roll-up of the member.

    摘要翻译： 提供了一种改进的阻塞，相对低成本的铅笔机构，其包括围绕机构的鼻套设置的环形弹性构件，用于将与其连接的衬套和引导引导件牢固地锁定在铅笔筒内的适当位置，同时 允许铅笔尖和引导引线螺纹连接，而不会沿着引导路径的长度产生开放的螺纹不连续性。 弹性构件用于吸收铅笔机构部件中的任何尺寸的不规则性，并允许铅笔尖端和引导引导件的全螺纹互锁，使得沿着引导路径不存在外露的螺纹，如果铅笔引线 在指南内破裂。 在优选的形式中，弹性构件是环形的锥形结构，允许在铅笔筒内伸缩定位，而不破坏构件的轴向卷起。

    Vehicle speed control
    6.
    发明授权
    Vehicle speed control 失效
    车速控制

    公开(公告)号：US3999622A

    公开(公告)日：1976-12-28

    申请号：US511907

    申请日：1974-10-03

    申请人： David F. Reed

    发明人： David F. Reed

    IPC分类号： B60K31/08 ,  B60K31/00

    CPC分类号： B60K31/08

    摘要： A pneumatic speed control device for an automotive vehicle that derives its power from a vehicle engine manifold vacuum and is an adaptive control which maintains a constant vehicle speed by means of changing the throttle position due to a deviation from vehicle speed which has been selected by the driver. This device includes a differential control valve for controlling a vacuum signal leading to a bellows actuating the throttle linkage of the vehicle and a speed sensing device including a control valve for a vacuum signal proportional to the vehicle speed and communicating with one side of a diaphragm in the differential control valve; the opposite side of the diaphragm communicating with an accumulator of a fixed volume which receives the vacuum signal from the speed sensing device and is isolated therefrom once the desired cruising speed is reached.

    摘要翻译： 一种用于从车辆发动机歧管真空导出其功率的机动车辆的气动速度控制装置，并且是一种自适应控制，其通过由于车辆速度的偏离而改变节气门位置而保持恒定的车辆速度 司机。 该装置包括差速控制阀，用于控制通向致动车辆的节气门联动装置的波纹管的真空信号;以及速度检测装置，其包括用于与车速成比例的真空信号的控制阀，并与隔膜的一侧连通 差速控制阀; 所述隔膜的相对侧与固定体积的蓄能器相通，其接收来自所述速度检测装置的真空信号，并且一旦达到所需的巡航速度就将其隔离。

    Constant speed drive
    7.
    发明授权
    Constant speed drive 失效
    恒速驱动

    公开(公告)号：US3982615A

    公开(公告)日：1976-09-28

    申请号：US547840

    申请日：1975-02-07

    申请人： David F. Reed

    发明人： David F. Reed

    IPC分类号： G05D13/32 ,  F16D25/02

    CPC分类号： G05D13/32

    摘要： A constant speed drive system which is automatically controlled according to the load of the pump, fan, etc. driven by the system. Control of the system is achieved by means of a pump or compressor and a diaphragm-actuated spool valve, wherein a reference point or pressure in a spool valve is matched with a pressure, proportional to the speed of the load or output shaft, acting on a diaphragm in the spool valve. The spool valve, in turn, modulates the pressure to a clutch actuator for a clutch located between a constant speed motor and a shaft driving the requisite load.

    摘要翻译： 恒速驱动系统，根据系统驱动的泵，风扇等的负载自动控制。 通过泵或压缩机和隔膜致动滑阀实现系统的控制，其中滑阀中的参考点或压力与负载或输出轴的速度成比例的压力匹配，作用于 滑阀中的隔膜。 滑阀又将压力调节到位于恒速电机和驱动所需负载的轴之间的离合器的离合器致动器。