In one embodiment, a foldable radome sub-assembly for an antenna reflector dish has flexible material connected to a plurality of rigid rim segments. Connection elements (e.g., inserts) are configured to interconnect two adjacent rim segments, such that, with the connection elements applied, the radome sub-assembly is configured as a radome connectable to the antenna reflector dish, and, without the connection elements applied, the radome sub-assembly is foldable between adjacent rim segments. The foldable radome sub-assembly can be folded up for efficient storage and shipping, yet is easy to configure in the field into a rigid radome for attachment to an antenna reflector dish.

Field of the Invention
The present invention relates to antennas and, more specifically but not exclusively, to radomes for reflector antennas.
Description of the Related Art
This section introduces aspects that may help facilitate a better understanding of the invention. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is prior art or what is not prior art.
Radomes are typically applied to the open end of reflector antennas to reduce wind load, improve antenna aesthetics, and/or seal/protect the feed assembly and/or reflector dish surfaces.
Prior radomes include rigid or semi-rigid dielectric polymer covers and flexible fabric covers held in tension across the open end of the reflector dish, for example, by a cord lattice and/or a plurality of springs. Rigid and semi-rigid polymer cover-type radomes may be expensive to manufacture and have a minimum dimension of the reflector dish opening which may be too large for cost-efficient transport. Flexible fabric radomes may be labor intensive to install and/or later remove to permit access to the reflector dish opening.


Disclosed is a method for determining internal uniaxial stress of steel members based on transverse wave phase spectrum, including: manufacturing a replicated steel member of an in-service steel structure member, where the replicated steel member and the in-service steel structure member are the same in material and thickness; loading a test on the replicated steel member to obtain two stress-spectral parameters; performing ultrasonic determination on the in-service steel structure member using an ultrasonic determination device; and collecting transverse wave signals using a signal acquisition system; processing the collected transverse wave signals through an information processing device to obtain a derived curve of the phase spectrum; capturing a first response frequency of the phase spectrum from the phase spectrum derived curve; and obtaining a uniaxial stress of the in-service steel structure member according to the stress-spectral parameters.

Due to the characteristics of small weight, high strength and excellent deformability, the steel structures have been currently popularized in engineering practice. However, due to the design limitations and the environmental physical and chemical effect, problems such as stress concentration will be inevitably caused inside the steel structure. If reinforcement and maintenance measures cannot be applied in time to solve these problems, an overall collapse of the structure may even occur over time. Similar accidents continuously happen around the world. Moreover, a considerable number of manpower and financial resources have been invested for the construction of large steel structure buildings, such as Bird′ Nest, Water Cube and other public landmark buildings, so that huge economic losses will be caused when the key stress member is destroyed by the excessive stress. Therefore, it is of significant importance for the steel structure buildings to timely obtain stress data of the steel member and analyze safety performance of the structure to take corresponding reinforcing and maintaining measures when the problems occur.
The traditional methods for the stress determination include a drilling method, a ring core method and a layer-removal strain method. In these methods, the member must be first damaged to release the stress, moreover, the involved devices are complex and the determination precision is poor. Compared to the traditional methods, the ultrasonic stress determination method can determine the internal stress of a steel member with a high precision. In addition, the equipments used in this method are convenient to operate and carry. Therefore, the ultrasonic stress determination technology has become one of the most commonly-used technical means in the stress determination of steel members.
Currently, the ultrasonic stress determination technology is mainly applied based on the development of an acoustic elastic technology, in which an acoustic elastic equation is established according to the relationship between the stress and the acoustic velocity or the acoustic time, so that the non-destructive determination of the stress is realized by measuring the acoustic velocity or the acoustic time.
On the basis of the above, those skilled in the art propose the use of critically refracted longitudinal wave, surface wave and the like to determine the mean absolute stress of the steel member. However, there are still some limitations in the ultrasonic stress determination method based on the acousto elastic principle, for example, time domain signals are difficult to extract; a known zero stress state is needed; and there are larger difficulties in the determination and more human errors. Therefore, it is required to develop a new method to determine the stress of the steel structure.

Method for determination of internal uniaxial stress of steel member based on phase spectrum of ultrasonic transverse wave

Harbin Institute of Technology, Shenzhen


A network transmitter and an associated transmitting method are disclosed. The network transmitter includes a signal converter and a signal driver. The former can convert an input signal into a current signal, and the latter can output a differential transmission signal according to the current signal. The signal driver includes a feedback network which can switch between a first configuration and a second configuration.

1. Field of the Invention
The present invention relates to network devices, and more particularly, to a transmitter of the network device and a method thereof.
2. Description of the Prior Art
Network technology is rapidly developed in recent years, and the demand for bandwidth is also growing increasingly. Along with this, the rate of network devices is upgraded from 10/100 Mbps to 1 Gbps. For example, each port of a 1 Gbps Ethernet device has four channels, each of which includes a transmitter and a receiver for transmitting and receiving differential transmission signals respectively, thereby communicating with other network devices.
FIG. 1 is a diagram of the transmitter of a conventional Ethernet device. As shown in FIG. 1, the transmitter 10 lies within an IC chip, and includes a voltage-controlled current source 11, a differential amplifier 12, and feedback resistors Rf1, Rf2.
To avoid the overshoot of the differential transmission signal, the voltage-controlled current source 11 performs slew rate control. That is, when the level of the differential transmission signal changes, the rise time (or fall time) is controlled to prevent the signal level from changing too fast. However, when the Ethernet device operates in 1 Gbps transmission rate, the voltage-controlled current source 11 is required to output a differential current with 17 levels, so as to match with 17 levels of the differential transmission signal defined in the related Ethernet specification. Thus, the circuit within the voltage-controlled current source 11 would be very difficult to design and would consume much more chip space.


A system for organizing a closet which comprises one or more pairs of slide rail assemblies and an appropriate number of baskets for mounting therebetween. Each rail assembly having an elongate mounting rail having at least one surface constructed and arranged to engage a partition, and an elongate slide rail, the elongate slide rail having at least one inner surface constructed and arranged to slidingly engage the elongate mounting rail. The elongate slide rail has an outer surface with a plurality of basket engaging hooks extending therefrom. The baskets have a double rim construction with one rim constructed and arranged to allows the baskets to be removingly secured to the hooks. A second rim being compatible with a U-channel slide. The basket may also be equipped with a pair of cross members which could be used to allows the basket to be received onto a roller slide. The hooks being flexibly adjustable so as to provide greater ability in securing a basket between the slide rails despite a lack of precise slide rail installation.

1. Field of the Invention
This invention relates to organizing a closet or other storage space with a unique sliding basket system. More particularly, the present invention is directed to a system of sliding rails and supported baskets. The sliding rails are unique in that they have a plurality of hooks which engage portions of the readily removable baskets. Once the baskets are engaged to the hooks the baskets may be slid on the sliding rails in a similar manner to a dresser drawer. The baskets may be freely lifted off of the hooks and be replaced as desired. In addition, the sliding rails may be fixed to any wall, support member or partition as desired, thereby allowing the rails to support a wide variety of basket shapes and sizes as well as providing for numerous configurations of slidable baskets within a storage space.
2. Description of the Related Art
As indicated above, the present invention is directed to storage space organization such as organizing closets. There are presently many products and services offered which claim to provide a consumer with a closet that is both organized and esthetically pleasing. Such closet organizer systems often have very specific partition widths and must be erected with great precision to provide for proper functioning of the system. As a result, many organizers require installation by professional designers and/or installers at significant expense to the consumer. These closet systems are often made of wood and/or laminate modules which partition the closet into compartments, with the various compartments corresponding to different types of items to be stored. The use of baskets in such systems is known. However, the present invention improves upon prior art systems by providing a sliding basket system which may be installed in a variety of configurations within a storage space. The present invention provides a system which is functional, esthetically pleasing, and which may be installed without a great degree of precision required.
The present invention is directed to a system for organizing a storage space which includes a unique type of storage basket. An additional element of the present system may also include a new slide assembly which may be used with the aforementioned basket. The basket has an inventive double rim which enables a user to use the basket with known, notched, single or full, extension slides and roller slides, or the basket may be mounted onto the unique slide assembly described in greater detail below. The present slide assembly has several mounting hooks which are constructed and arranged to receive portions of the basket rims.
The present double rimmed basket and rail assembly provides for an organizational system wherein the spacing provided for the basket between slide assemblies does not have to be as precise as is required by many prior art systems. In at least one embodiment of the present invention the respective rims of the double rim basket have different spacings, with at least one rim being wider than the remaining portions of the basket. By providing a basket which has more than one size of mounting surface, the present basket may be placed onto and between slide assemblies having a variety of spacings. Additionally, in at least one embodiment of the invention, the hooks of the slide assembly may be flexible or otherwise adjustable, thereby providing the slide assemblies themselves with at least a limited ability to vary the basket mounting space provided.


Systems and methods for designing a dummy pattern layout for improving surface flatness of a wafer are provided. An exemplary system includes at least one processor and at least one memory storing instructions. The instructions, when executed by the at least one processor, cause the at least one processor to perform operations. The operations include identifying a feature pattern corresponding to a functional region of the wafer. The operations also include determining a property of the feature pattern based on a script associated with the feature pattern. The operations further include determining a dummy pattern rule based on the property of the feature pattern. Moreover, the operations include generating a dummy pattern corresponding to a vacant region of the wafer by wrap-filling dummy units in an adjacent area surrounding the feature pattern based on the dummy pattern rule.

Embodiments of the present disclosure relate to computer assisted design-for-manufacturing (DFM) and electronic design automation (EDA) in semiconductor design, and more particularly, to application of dummy patterns in semiconductor design such as three-dimensional (3D) memory device design.
DFM refers to a process of designing or engineering a product in light of facilitating the manufacturing process in order to reduce its manufacturing costs. DFM will allow potential problems to be fixed in the design phase which is the least expensive place to address them. In semiconductor industry, DFM involves defining clearance and/or tolerance among parts and components of a semiconductor device, ensuring flatness of interfaces between layers, etc.
DFM is often implemented using EDA tools, which include software tools for designing electronic systems such as integrated circuits and printed circuit boards. The tools work together in a design flow that chip designers use to design and analyze entire semiconductor chips. Since a modern semiconductor chip can have billions of components, EDA tools are essential for their design.

Systems and methods for designing dummy patterns


An indentation hardness test system includes a frame including an attached indenter, a movable stage for receiving a part attached to the frame, a camera, a display, a processor and a memory subsystem. The camera captures images of the part, which can then be provided on the display. The processor is coupled to the movable stage, the camera and the display, as well as the memory subsystem. The memory subsystem stores executable code that instructs the processor to capture a series of real-time images of the part using the camera, obtain associated stage coordinates for each of the images and display a composite image, which includes the series of real-time images assembled according to the associated stage coordinates, of the part.

The present invention is generally directed to a test system and, more specifically, to an indentation hardness test system.
Hardness testing has been found to be useful for material evaluation and quality control of manufacturing processes and research and development endeavors. The hardness of an object, although empirical in nature, can be correlated to tensile strength for many metals and provides an indicator of wear-resistance and ductility of a material. A typical indentation hardness tester utilizes a calibrated machine to force a diamond indenter (of a desired geometry) into the surface of a material being evaluated. The indentation dimension (dimensions) is (are) then measured with a light microscope after load removal. A determination of the hardness of the material under test may then be obtained by dividing the force applied to the indenter by the projected area of the permanent impression made by the indenter.
In a typical situation, an operator of an indentation hardness tester is required to position indents into a part at precise distances from various part geometries. With reference to FIGS. 2 and 3, an operator may be required to place a series of five evenly spaced indents 302 into a surface of a tooth 102A of a portion of, for example, a gear 102 being tested and mounted within a plastic 104 to form a test assembly 22. The indents 302 may be spaced 200 microns (±5 microns) from each other and centered in a face of the tooth 102A. Assuming that the tooth 102A is approximately 0.5 cm wide by 0.5 cm tall and the tester has two magnifications, i.e., a high power 50× objective with a field of view 200 microns wide and a 5× magnification with a field of view 2000 microns wide, and assuming that an image of the tooth 102A is displayed on a display having a width of 640 pixels, the width of each pixel is about 0.3 microns at 50× and about 3.0 microns at 5× magnification.
In such a tester, a 5× magnification only allows an operator to see about ⅕th of the top surface of a tooth and a 50× magnification only allows the operator to see about 1/50th of the top surface of a tooth. It should be appreciated that such a view does not allow an operator to precisely know if a stage that is used to position the test assembly 22 is positioned in the center of the top surface of the tooth. Thus, to ensure that indentations are perpendicular to the top of the tooth 102A and a specified distance from the top surface of the tooth 102A, traditional software packages have allowed an operator to position a "T" bar along a displayed image. In this manner, an operator would position the top portion of the "T" bar along the top edge of the tooth 102A through a combination of moving the stage and rotating the "T" bar. As briefly described above, at 5× magnification the operator has a relatively good idea of the required orientation of the "T" bar, but not enough resolution to position it within 5 microns of the edge. Further, at 50× magnification, locating the top edge of the tooth within 5 microns is possible, but the orientation is difficult because the edge is not straight at this magnification.
What is needed is a technique that more readily allows an operator of an indentation hardness tester to properly position an indenter with respect to a test assembly.

This patent is subject to a terminal disclaimer.


An optical switch comprises a heterojunction transistor having a source electrode, a gate, a mesa, and three self-aligned waveguides, the mesa being ion implanted and having a single quantum well under the gate electrode, the single quantum well being comprises of undoped, narrow bandgap material bound on both sides by regions p-doped, wide bandgap material, both of said p-doped regions have symmetrically graded bandgaps, being most narrow next to the quantum well and increasing out to a wide and constant value away from the quantum well. A highly n-doped and totally depleted charge sheet is placed in a wide bandgap material, very near the gate side of the quantum well heterojunction. The charge sheet serves to induce a voltage controllable inversion channel within the quantum well. A source of optical energy is applied to one of said waveguides, and a total internal reflection is created in the switch by inducing a change in refractive index under the gate by means of a charge applied from the source electrode.

Development of an integrated Total Internal Reflection (TIR) optical switch necessitates the creation of a region of light propagation with controllable change in refractive index. This region with refractive index change has an effective change in reflectivity to the incident light via the Fresnel relations.
The Fresnel relations describe the reflection and transmission of light as it is incident on an interface between two regions at some angle of incidence. The amount of light transmitted and reflected depends on both the angle of indigence and the difference in the refractive indices of the two regions. For a fixed difference in refractive index between the two layers there is some angle for which all of the incident light is reflected. This is called total internal reflection, and the incident angle producing it is called the critical angle. Similarly, for a fixed angle of incidence there is some refractive index difference that also creates total internal reflection. Also, if the is no difference in refractive index between the two regions, then the reflection is zero for all angles. By increasing the difference in the refractive indices between the two regions, the critical angle becomes closer to the normal to the interface. By making the critical angle closer to the normal to the interface, the physical area used by the switch and the associated waveguide ports is reduced. This means that the maximum controllable change in index of refraction is desirable to create the smallest integral TIR optical switch. The TIR optical switch uses a fixed angle of incidence between the input waveguide and the controlling electrode of the TIR optical switch, and then uses control of the refractive index difference between the waveguide region and the controlling electrode region to operate the device. Knowledge of the refractive index difference obtainable with the TIR optical switch allows the fixed incident angle to be chosen so that the total internal reflection of the incident light is obtained when the device is on.
Control of this change allows selection of the incident light to be transmitted (TIR off) to output port 1, or reflected (TIR on) to output port 2. Current investigation into creating this controllable change in refractive index for use in a TIR optical switch is centered in two major areas. One uses a forward biased p-n junction in which the light is incident laterally on the junction (see K. Ishida et al, InGaAsp/InP Optical Switches Using Carrier Induced Refractive Index Change, Applied Physics Letters, Volume 50(3), pp 141-142, 19 Jan. 1987). The other uses an electric field applied perpendicularly to a multiple quantum well region where the incident light is perpendicular to the applied field (see H. Yamamoto et al, Intersectional Waveguide Type Optical Switch With Quantum Well Structure, Transaction of the IECE of Japan, Volume E68, pp 737-739, 1985).
The forward biased p-n junction TIR switch is based on the change in refractive index due to the introduction of free carriers in the junction. The magnitude of change is limited only by the maximum forward bias current of the junction, i.e., the amount of charge in the junction. However, the forward biased p-n junction TIR switch is limited in speed by the recombination lifetimes of the electron-hole pairs, which is on the order of a few nanoseconds.
The electric field controlled TIR switch uses the refractive index change attributable to the Quantum Confined Stark Effet (QCSE) found at room temperature in quantum wells. (For example, see Weiner et al, Quadratic Electro-Optic Effect Due To The Quantum-Confined Stark Effect in Quantum Wells, Applied Physics Letters, Volume 50(13), pp 842-844, 30 Mar. 1987). The QCSE optical switch is based on the change in excitonic absorption within a quantum well due to an applied electric field. This change in absorption is coupled to a change in refractive index via the Kramers-Kronig relations. Typical device geometries use a reverse biased p-i-n structure, where the multiple quantum wells compose the intrinsic region. The switching capability of these devices is limited by the breakdown field of the material (approximately 10.sup.+5 V/cm). It is noted that the apparent breakdown field (i.e., when the destructive breakdown of the device occurs) is lowest in a p-i-n junction because the field creates a large depletion region in which many impact ionization collisions may occur. If the high field region were to be limited to a small volume, say a single quantum well, such that sufficient energy for ionization cannot be obtained, then a field much higher than the p-i-n junction breakdown may be applied without device breakdown.

Integrated total internal reflection optical switch utilizing charge storage in a quantum well

The United States of America as represented by the Secretary of the Air Force


A packet transfer device that can be easily realized even when a number of input ports is large. Each input buffer temporarily stores entered packets class by class, and outputs packets of a selected class specified by the control unit, while the control unit determines the selected class of packets to be outputted from the input buffers according to a packet storage state in the packet storage units of the input buffers as a whole for each class. Each input buffer can temporarily store entered packets while selecting packets to be outputted at a next phase, and the control unit can specify packets to be selected in the input buffers according to an output state of packets previously selected in the input buffers as a whole. Packets stored in the buffer can be managed in terms of a plurality of groups, and each packet entered at the buffer can be distributed into a plurality of groups so that packets are distributed fairly among flows. The packets belonging to one of a plurality of groups are then outputted from the buffer toward the output port. A packet transfer at the buffer can be controlled by issuing a packet transfer command according to a log of packet transfer commands with respect to the buffer and a packet storage state of the buffer.

1. Field of the Invention
The present invention relates to a packet transfer device such as a cell multiplexing device and a cell buffer device in an ATM communication network. Since a cell switch can be formed by combining a plurality of cell multiplexing devices, the present invention is also applicable to a cell switch which has each output port in a configuration of a cell multiplexing device according to the present invention. The cell buffer device of the present invention is not necessarily limited to handling of cells and is applicable to a buffer device in general. The present invention is also not necessarily limited to an application to the ATM communication network and is applicable to a packet switching network as well.
2. Description of the Background Art
Currently, researches on an ATM (Asynchronous Transfer Mode) communication scheme are actively conducted by researchers of the communication technology throughout the world. In an ATM communication scheme, fixed length packets called cells are used to transmit and switch information. In an ATM communication scheme, a high speed cell switching can be realized by a cell switch provided by the hardware inside a switch node, so that it is possible to realize an information transfer performance per unit time much superior than those of the existing communication networks.
An ATM communication scheme can set up a plurality of logical connections (Virtual Connection: VC) in one physical transmission link by using a connection identifier information called VPI (Virtual Path Identifier) and VCI (Virtual Channel Identifier) to be provided in a header of a cell. At each switch node within the network, routes are set up in advance for each VC, and the switch node determines an output route for outputting the cell according the connection identifier VPI and VCI of the cell. VPI and VCI are uniquely assigned at each physical transmission link between the switch nodes, so that the switch node has a function for rewriting values of VPI and VCI of a passing cell.
Up to now, the VC for which the quality is guaranteed in the ATM network has been either a CBR (Constant Bit Rate) connection or a VBR (Variable Bit Rate) connection. The CBR connection is a VC for transmitting the traffic in which the cell transmission rate (that is, a number of transmission cells per unit time, which is also referred to as a cell rate or a bandwidth) is constant and known in advance. The VBR connection is a VC for transmitting the traffic in which the cell transmission rate is not constant but some traffic characteristics such as a maximum value (peak rate) and an average value (average rate) are known in advance.
Basically, in a case of multiplexing a plurality of VCs in one physical transmission link while maintaining a sufficient quality, it is sufficient for a sum of the peak rates of all the VCs to be not greater than the bandwidth of the physical transmission link. This scheme is called a peak rate allocation. It is possible for the peak rate allocation to realize a sufficiently high physical transmission link utilization efficiency in a case of dealing only with the CBR connections, but a physical transmission link utilization efficiency cannot be very high in a case of dealing with the VBR connections. For this reason, there are many studies on a technique for improving the physical transmission link utilization efficiency by using the statistical multiplexing effect according to the traffic characteristics known in advance while maintaining the quality.
However, the ATM communication between computers is characterized by the fact that the traffic characteristics such as an average rate cannot be predicted in advance, and the characteristic called burstiness which indicates a coexistence of some timing at which a large amount of cells are transmitted instantaneously and some other timing at which no cell is transmitted. Consequently, for the ATM communication between computers, it is difficult to improve the network utilization efficiency while maintaining the quality by using the techniques used for CBR and VBR.
More specifically, for data transferred between computers, when the peak rate allocation is utilized to guarantee the quality, the network utilization efficiency will be lowered considerably, whereas when the statistical multiplexing effect is utilized as in a case of VBR, a large amount of cells arrive simultaneously at some output port of the cell switch because of the burstiness of the traffic, and the cell loss due to the buffer overflow will be caused unless a sufficient buffer capacity is provided at the cell switch. In addition, when the cell loss is caused, a re-transmission in unit of a packet formed by a plurality of cells will be carried out, so that the effective throughput will be lowered.
For this reason, in recent years, a service class called ABR (Available Bit Rate) has been proposed and studied. In this ABR, the network utilization efficiency is improved while guaranteeing the cell transfer quality (especially a quality concerning cell loss) by applying a flow control between terminals and switch nodes. In the ABR connection, when the switch node is about to fall into the cell congestion state, the source terminals are controlled to suppress cell transmissions before the cell congestion occurs at the switch node. Here, the traffic control information to be given to terminals is mainly carried by a cell called RM (Resource Management) cell. This traffic control from the switch node to the source terminal in the ABR has an unignorable delay time, so that there is a need to implement a large capacity buffer at the cell switch so as not to discard cells until the traffic control begins to function effectively.
Apart from these CBR, VBR and ABR, there is a service class called UBR (Unspecified Bit Rate) which is a class of the so called best effort service in which a terminal is not required to declare the characteristics of traffic to be outputted in detail to the network, but instead the network does not guarantee the transfer quality at all.
As described above, data between computers have the burstiness, so that in order to realize a satisfactory level of the cell loss rate for the UBR connections, it is considered that the implementation of a large capacity cell buffer in the cell switch is necessary.
Fortunately, the transfer delay time and the transfer delay jitter required by the traffic between computers are often not so severe compared with those required for the CBR and VBR. By implementing a large capacity cell buffer in the cell switch, the delay time and the delay jitter for the cell transmission increase, but it is considered that there are many applications that can tolerate such an increase of the delay time and the delay jitter.
In particular, in a case of the ABR and UBR services, it is considered necessary to provide means for avoiding the congestion of the network. One known means for avoiding the congestion is the so called EFCI (Explicit Forward Congestion Indication). In the EFCI, a header of each cell has an EFCI bit as an indication of a congestion experienced by that cell, and a cell switch within the network marks the EFCI but according to the congestion state. As each terminal utilizes the information of the EFCI, it becomes possible to avoid the congestion.
Next, the conventional per-VC fair queueing in the cell multiplexing device and the cell switch will be described.
First, the per-VC fair queueing which is required as the robustness in the ABR service will be described.
The ABR service works as the source terminal controls the transmission of cells according to the traffic control information given from the network. If some terminal ignores (either by fault or intentionally) the traffic control information given from the network, it may be difficult to recover from the congestion of the network.
This problem can be resolved by carrying out the per-VC fair queueing at a cell multiplexing device or a cell switch, so as to realize the fair cell multiplexing scheduling among VCs and the fair buffer allocation among VCs. By carrying out the per-VC fair queueing, the interaction among VCs can be suppressed to the minimum, and even if there is a VC which ignores the traffic control information, only that VC would fall into the congestion and the influence of that VC to the other VCs can be suppressed.
In addition, the per-VC fair queueing is also required from the fairness of the UBR service.
FIG. 1 shows an example of an unfair bandwidth allocation in the UBR service. In this example, the network has four terminals A, B, C and D, and one file server FS, which are connected through cell switches (or cell multiplexing devices) X, Y and Z and links 1, 2, 3, 4, 5, 6 and 7.
Now, when each cell switch is to multiplex cells regardless of a number of VCs set up to its input links, each cell switch treats the input ports equally. For example, at the cell switch X, in a case of multiplexing cells from the links 2 and 3 into the link 1, the cell switch X treats both links equally, so that if the bandwidth of the link 1 is 1.0, the bandwidth of 0.5 would be given to each of the links 2 and 3.
By the similar consideration, the bandwidth eventually given to each terminal would have the largest value 0.5 for the terminal A and the smallest value 0.125 for the terminals C and D. This is far from the ideal in which all terminals should be making accesses to the file server FS equally.
In addition, when the network falls into the congestion, the network transmits the EFCI information so that each terminal makes its bandwidth smaller. At this point, if there are terminals which obeys the EFCI information faithfully and terminals which ignore the EFCI information within the network, there is a problem in that only the terminals which are faithful to the EFCI information would suppress the cell transmission, and the terminals which ignore the EFCI information would end up obtaining unfairly large bandwidth resources.
These problems are caused by the fact that the cell switch treats the input links equally by ignoring a number of VCs multiplexed in each link. When the cell switch carries out the per-VC fair queueing and distributes the bandwidth according to a number of VCs, it becomes possible for the terminals to make accesses to the file server fairly.
Next, the conventional cell multiplexing device for carrying out the priority control among classes will be described.
FIG. 2 shows a configuration of a conventional cell multiplexing device for carrying out the priority control among classes. This cell multiplexing device of FIG. 2 is for multiplexing cells entered from N pieces of input ports into one piece of output port.
In the output buffer 101, cells of each class are separated by a class separation unit 102, and stored in a cell storage unit (101-1, 101-2, or 101-3) for each class provided therein, and a cell selection unit 103 selectively outputs cells to the output port according to the priority level of each class.
In addition, a number of cells stored in each buffer storage unit of the output buffer 101 is compared with a threshold value to generate a respective backpressure signal.
Each input buffer 100 also has a cell storage unit (100-1, 100-2, or 100-3) for each class, and cells are transferred to the output buffer 101 according to the priority level of each class among the classes which are permitted to output cells according to the backpressure signals.
In this configuration, there is a need to provide a plurality of cell storage units class by class in the output buffer, so that there is a drawback in that the realization of the output buffer becomes difficult when a number of classes increases. In particular, it has been necessary for the input rate of the output buffer to be N times greater (where N is a number of input ports) than a rate at the input port, so that when a number of classes and a number of input ports are large, it has been difficult to realize the output buffer with such complicated functions.
When the configuration of FIG. 2 is considered as one output port portion of a cell switch, the same problem also exists for the the cell switch which has buffers for the input ports.
Next, the conventional cell multiplexing device will be described. Here, the problems associated with a cell multiplexing device having input buffers as shown in FIG. 3 will be described.
FIG. 3 shows a cell multiplexing device for multiplexing cells entered from N input ports into one output port.
The output buffer 111 temporarily stores cells from the input ports and outputs cells according to a rate of an output port.
A number of cells stored in the output buffer 111 is compared with a threshold value to generate a backpressure signal. The input buffer 101 has one queue in correspondence to the output port, and transfers cells to the output buffer 111 only when the output is permitted by the backpressure signal.
Such a cell multiplexing device treats the input buffers 110 equally regardless of a number of VCs set up, so that there has been problems concerning the robustness in the ABR service and the fairness in the UBR service.
When the configuration of FIG. 3 is considered as one output port portion of a cell switch, the same problem also exists for the the cell switch which has buffers for the input ports.
Next, the conventional per-VC fair queueing in the cell buffer device will be described.
FIG. 4 shows a configuration of FIFO for each VC which realizes the per-VC fair queueing.
FIG. 4 shows a case of a cell buffer device in which the connection identifier information of the cell entered from the input link is notified to a buffer pointer management unit 130, the cell is temporarily stored in a cell buffer 131 by obtaining a write pointer indicating a writing position of the cell given from the buffer pointer management unit 130, and the cell is read out from the cell buffer 131 according to a read pointer indicating a cell to be read out given from the buffer pointer management unit 130 and outputted to the output link. The buffer pointer management unit 130 manages a buffer pointer indicating a position of each stored cell on the cell buffer 131.
Here, the buffer pointer management unit 130 manages the buffer pointer for each VC by using a VC table. FIG. 4 shows a well known management scheme using the pointer chain.
When the cell is entered, a buffer pointer is taken out from a head of an idle chain as the write pointer, and attached to a tail of the chain for VC corresponding to the input cell. At a time of outputting cell, a VC storing the cell is selected fairly, and a buffer pointer at its head is taken out as a read pointer. As a method for selecting a VC fairly at a time of cell output, the round robin scheme is known.
In order to select a VC by the round robin scheme, it is necessary to carry out the sequential search through the VC table as to whether there is any cell stored in the buffer, starting from a VC next to a VC which was outputted previously. It may be necessary to carry out this search for as many as almost all VCs within one cell period, but there are cases in which a number of VCs to be set up is well over several thousands, so that it has been difficult to realize this scheme in practice.
Next, the conventional cell buffer device for carrying out the priority control will be described.
FIG. 17 shows an exemplary configuration of a conventional cell buffer device for carrying out the priority control.
This cell buffer device of FIG. 17 has a class-1 cell storage unit 500-1 for temporarily storing cells with a low priority concerning the delay and a class-2 cell storage unit 500-2 for temporarily storing cells with a high priority concerning the delay, and their outputs are multiplexed by a class multiplexing FIFO 510.
A class management unit 520 receives a number of cells Na in the class-2 cell storage unit 500-2, and a number of cells Nb in the class multiplexing FIFO 510 as inputs, and issues a transfer commands to either class-1 or class-2, so that only the cell storage unit 500 of a class which received the transfer command will transfer cells to the class multiplexing FIFO 510.
In order to improve the performance of the priority control in this cell buffer device of FIG. 17, it is necessary to keep a number of cells stored in the class multiplexing FIFO 510 small, but in order not to lower the throughput, it is necessary to command the transfer so that the class multiplexing FIFO 510 will not become empty as much as possible (that is, so as not to cause the underflow in the class multiplexing FIFO 510). In addition, when either one of the cell storage unit 500 is empty, if the transfer is commanded to the empty cell storage unit 500 (a case which will be referred to as a vain-command in the following description), there would be a possibility for causing the underflow, so that it is necessary to issue the transfer command with respect to the cell storage unit 500 in which a stored cell exists.
According to these policies, the condition by which the class management unit 520 issues the transfer command to the class-2 cell storage unit 500-2 can be given by:
(Nbxe2x89xa61) and (Naxe2x89xa71),
while the condition for the transfer command to the class-1 cell storage unit 500-1 can be given by:
xe2x80x83(Nbxe2x89xa61) and (Na=0).
Now, consider a case in which the delay times exist for a transmission of a number of cells information from the cell storage unit 500 or the class multiplexing FIFO 510 to the class management unit 520, a transmission of the transfer command from the class management unit 520 to the cell storage unit 500, and a cell transfer from the cell storage unit 500 to the class multiplexing FIFO 520. In such a case, the following problems are encountered conventionally.
First, due to these delay times, it has been impossible for the class management unit 520 to accurately judge whether the underflow is going to be caused in the class multiplexing FIFO 510 or not. For this reason, conventionally, the condition for not causing the underflow has been given by the comparison of a number of cells within the class multiplexing FIFO with a threshold value which is set larger for the delay time part. As a result, the average queue length of the class multiplexing FIFO 510 has been made longer, and this in turn has been lowering the performance of the priority control.
Also, because of the delay of a transmission of the information from the high priority class-2 cell storage unit 500-2, it has been impossible to accurately judge whether the class-2 cell storage unit 500-2 becomes empty or not. For this reason, there have been a case of issuing the vain-command by judging an actually empty state erroneously as not empty, or a case in which the output of the low priority class-1 cells with priority over the high priority class-2 cells is commanded by judging an actually not empty state erroneously as empty. As a result, the problems of a lowering of the throughput of the cell buffer device or a lowering of the performance have been encountered conventionally.
Note that the similar problems can also arise in various cell buffer devices other than the cell buffer device for carrying out the priority control. Namely, in a cell buffer device in which a management unit commands the cell transfer among a plurality of buffers, when the delay times exist for a transmission of a buffer information to the management unit, a transmission of the transfer command from the management unit to the buffer, and a cell transmission among the buffers, the similar problems of a lowering of the throughput of the cell buffer device or a lowering of the performance have been encountered conventionally.
As described, the conventional cell multiplexing device is associated with the following two problems.
Firstly, as there is a need to provide a plurality of cell storage units class by class in the output buffer, the realization of the output buffer becomes difficult when a number of classes increases. In particular, it has been necessary for the input rate of the output buffer to be N times greater (where N is a number of input ports) than a rate at the input port, so that when a number of classes and a number of input ports are large, it has been difficult to realize the output buffer with such complicated functions.
Secondly, as the conventional cell multiplexing device treats the input buffers equally regardless of a number of VCs set up, there has been problems concerning the robustness in the ABR service and the fairness in the UBR service.
On the other hand, the conventional cell buffer device is associated with the following problems.
Namely, in order to select a VC by the round robin scheme, it is necessary to carry out the sequential search through the VC table as to whether there is any cell stored in the buffer, starting from a VC next to a VC which was outputted previously. It may be necessary to carry out this search for as many as almost all VCs within one cell period, but there are cases in which a number of VCs to be set up is well over several thousands, so that it has been difficult to realize this scheme in practice.
In this regard, recently, there is a proposition of an algorithm to resolve this problem, as disclosed in M. Shreedhar and G. Varghese: xe2x80x9cEfficient Fair Queueing using Deficit Round Robinxe2x80x9d, ACM SIGCOMM ""95, pp. 231-242, August 1995. This algorithm called DRR proposed in this paper manages VCs storing cells by using a concept of an active list, so that the search through the VC table is not necessary at a time of cell output. Consequently, even when a number of VCs to be set up is increased, it is possible to realize the selection of a cell to be outputted at high speed for the purpose of the per-VC fair queueing.
However, this DRR algorithm has a drawback in that a number of packets in proportion to a value of weight set up to each VC will be outputted at once because the packets are stored in the VC by VC classification, so that the output traffic resulting from this DRR algorithm will be very bursty.
In addition, in a cell buffer device in which a management unit commands the cell transfer among a plurality of buffers, when the delay times exist for a transmission of a buffer information to the management unit, a transmission of the transfer command from the management unit to the buffer, and a cell transmission among the buffers, the problems of a lowering of the throughput of the cell buffer device or a lowering of the performance have been encountered conventionally.
It is therefore an object of the present invention to provide a packet transfer device and a packet transfer method using the priority control among classes, which are easy to realize even when a number of input ports is large.
It is another object of the present invention to provide a packet transfer device and a packet transfer method capable of carrying out the per-VC fair queueing which realizes the robustness in the ABR service and the fairness in the UBR service.
It is another object of the present invention to provide a packet transfer device and a packet transfer method capable of carrying out the per-VC fair queueing which can be realized easily without being affected by an upper limit of a number of VCs that can be set up.
It is another object of the present invention to provide a packet transfer device and a packet transfer method capable of preventing a lowering of the throughput or the performance of the priority control when a management unit commands the cell transfer among a plurality of buffers, even if the delay times exist for a transmission of a buffer information to the management unit, a transmission of the transfer command from the management unit to the buffer, and a cell transmission among the buffers.
According to one aspect of the present invention there is provided a packet transfer device, comprising: a plurality of input buffers for temporarily storing packets belonging to a plurality of classes; a control unit for controlling the input buffers; and at least one output port for transferring packets outputted from the input buffers; wherein each input buffer has packet storage means for temporarily storing entered packets class by class, and an output means for outputting packets of a selected class specified by the control unit from the packet storage means toward the output port; and the control unit determines the selected class of packets to be outputted from the input buffers according to a packet storage state in the packet storage means of the input buffers as a whole for each class, and issues a command specifying the selected class to the input buffers.
According to another aspect of the present invention there is provided a packet transfer device, comprising: a plurality of input buffers for temporarily storing packets; a control unit for controlling the input buffers; and at least one output port for transferring packets outputted from the input buffers; wherein each input buffer has packet storage means for temporarily storing entered packets, selection means for selecting packets to be outputted from the packet storage means, and an output means for outputting packets selected by the selection means toward the output port; and the control unit issues a command commanding a selection of packets by the selection means of the input buffers according to an output state of packets previously selected by the selection means in the input buffers as a whole.
According to another aspect of the present invention there is provided a packet transfer device, comprising: a buffer for temporarily storing entered packets; a control unit for controlling the buffer; and at least one output port for transferring packets outputted from the buffer; wherein the control unit has management means for managing packets stored in the buffer in terms of a plurality of groups, distribution means for distributing each packet entered at the buffer into one of said plurality of groups so that packets are distributed fairly among flows to which packets belong, and control means for commanding the buffer to output packets belonging to one of said plurality of groups managed by the management means toward the output port.
According to another aspect of the present invention there is provided a method of packet transfer in a packet transfer device formed by a plurality of input buffers for temporarily storing packets belonging to a plurality of classes, a control unit for controlling the input buffers, and at least one output port for transferring packets outputted from the input buffers, the method comprising the steps of: temporarily storing entered packets class by class at each input buffer; determining a selected class of packets to be outputted from the input buffers according to a packet storage state in the input buffers as a whole for each class, and issuing a command specifying the selected class from the control unit to the input buffers; and outputting temporarily stored packets of the selected class specified by the command of the control unit from each input buffer toward the output port.
According to another aspect of the present invention there is provided a method of packet transfer in a packet transfer device formed by a plurality of input buffers for temporarily storing packets, a control unit for controlling the input buffers, and at least one output port for transferring packets outputted from the input buffers, the method comprising the steps of: temporarily storing entered packets at each input buffer; selecting packets to be outputted from each input buffer among temporarily stored packets; issuing a command commanding a selection of packets by the selecting step from the control unit to the input buffers, according to an output state of packets previously selected by the selecting step in the input buffers as a whole; and outputting temporarily stored packets selected by the selecting step from each input buffer toward the output port.
According to another aspect of the present invention there is provided a method of packet transfer in a packet transfer device formed by a buffer for temporarily storing entered packets, a control unit for controlling the buffer, and at least one output port for transferring packets outputted from the buffer, the method comprising the steps of: managing packets stored in the buffer in terms of a plurality of groups; distributing each packet entered at the buffer into one of said plurality of groups so that packets are distributed fairly among flows to which packets belong; and outputting packets belonging to one of said plurality of groups managed by the managing step from the buffer toward the output port.
According to another aspect of the present invention there is provided a packet transfer device, comprising: at least one buffer for temporarily storing entered packets; and a control unit for controlling a packet transfer at the buffer, by issuing a packet transfer command to the buffer according to a log of packet transfer commands with respect to the buffer and a packet storage state of the buffer.
According to another aspect of the present invention there is provided a method of packet transfer in a packet transfer device formed by at least one buffer and a control unit for controlling a packet transfer at the buffer, the method comprising the steps of: temporarily storing entered packets at the buffer; and controlling a packet transfer at the buffer, by issuing a packet transfer command from the control unit to the buffer according to a log of packet transfer commands with respect to the buffer and a packet storage state of the buffer.
Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings.

Packet transfer device and packet transfer method adaptive to a large number of input ports


A light socket is disclosed that has a built-in integrated circuit for rectifying the alternating current received from an electrical outlet and limiting the direct current produced. The light socket is specifically suited for low-current, low-voltage applications such as supplying DC to a string of ornamental lights. The integrated circuit has a diode with a modified cathode that acts as a fuse as it is rectifying the alternating current. The cathode is formed of a plurality of electrically parallel conductors. Excessive current blows out at least some of these conductors in the same way a conventional fuse blows. Various embodiments add other current-limiting elements, elements for producing full wave or near full wave rectification, and for opening the circuit when they detect extraneous currents.

1. Field of the Invention
The present invention relates to small wattage electrical power needs such as ornamental light strings for decorating trees. In particular, the present invention relates to integrated circuits for rectifying and limiting current from an AC source.
2. Discussion of Background
Strings of individual, small wattage lights are widely used to decorate Christmas trees. Although these types of decorations are enjoyed by many people, they are sometimes a fire hazard, resulting in tragedies every Christmas holiday season. Most of these light strings draw a current of at least 200 ma at 120 VAC. Because of the concern over safety, these light strings may be made with heavier gauge wire, such as 22 gauge rather than 24. However, even though a single string of lights may be hazardous, the common practice of cascading multiple strings of lights from one wall socket compounds this inherent danger associated with a single string.
In addition to Christmas tree light strings, there are other applications for electrical power for devices that have low power needs and especially those that use direct current (DC) rather than alternating current (AC), including many devices that use integrated circuits, such as calculators or devices that use light-emitting diodes. AC or large voltage surges can ruin these types of devices.
There have been some attempts to make Christmas tree decorations safer. Many of these involve putting fire or smoke detectors in ornaments. An example of this can be found in U.S. Pat. No. 4,075,614 issued to White and in U.S. Pat. No. 5,396,221 issued to Bridges. Fuses have been incorporated into the plugs of light strings, as taught for example by Cheng in U.S. Pat. No. 4,227,228 and Lehmann et al in U.S. Pat. No. 3,968,398. However, none of these address all of the problems with these types of light strings.
Smith et al, in U.S. Pat. No. 4,675,575, describe a light string based on light-emitting diodes (LEDs) which can be driven by pulsed DC power, which in turn is powered by household AC voltage. The pulsed DC is produced by a silicon controlled rectifier from the AC input.
DC is not unknown in connection with Christmas tree lighting using more conventional type incandescent bulbs. See Wu's stages selection type Christmas tree light controller circuit in U.S. Pat. No. 5,345,147, and Kramer's decorative lighting system in U.S. Pat. No. 3,789,211. However, in both cases the DC power is used only tangentially in achieving a particular lighting effect and not to power the bulbs themselves.
Turning briefly to the figures, FIGS. 1A, 1B and 1C illustrate graphs of voltages versus time, with voltage represented by the vertical coordinate and time represented by the horizontal coordinate.
FIG. 1A illustrates an alternating current (AC), meaning that the current reverses the direction of flow. So-called household current varies between approximately .+-.60 volts and does so at approximately 60 times per second. Direct current (DC) does not change direction, although it may change amplitude. FIGS. 1B and 1C both illustrate DC; FIG. 1B shows half-wave DC and FIG. 1C shows full wave DC. Both also illustrate pulsed DC.
It is known to generate half-wave and full wave DC from AC by devices called converters or rectifiers. Devices for rectifying AC to DC are sometimes based on diodes, which are solid state circuit elements that conduct current in the forward direction but not in the reverse direction. For half-wave rectification, as illustrated in FIG. 1B, a single diode can exclude negative voltages, leaving only positive voltages. For full-wave rectification, two or four diodes are used.
Some of the patents identified above employ diodes in various functions in relation to power sources, such as disclosed by Smith et al. However, there remains a need for a better way to power low wattage devices and Christmas tree light strings in particular.


A process control instrument comprises a control for generating or receiving a high frequency signal. A waveguide comprises a cylindrical housing closed at one end by a rear wall. A loop launcher is operatively connected to the control and comprises a wire having a first straight leg electrically connected at one end to the control and extending into the waveguide a first select length. A second straight leg is connected at one end to the rear wall and extends into the waveguide a second select length, greater than the first select length. A curved middle section connects the other ends of the first and second straight legs. An antenna is operatively coupled to the waveguide.

Industrial processes often require measuring the level of liquid or other material in a tank. Many technologies are used for level measurement. With contact level measurement some part of the system, such as a probe, must contact the material being measured. With non-contact level measurement the level is measured without contacting the material to be measured. One example is non-contact ultrasound, which uses high-frequency sonic waves to detect level. Another example is use of high-frequency or microwave RF energy. Microwave measurement for level generally uses either pulsed or frequency modulated continuous wave (FMCW) signals to make product level measurements. This method is often referred to as through air radar. Through air radar has the advantage that it is non-contact and relatively insensitive to measurement errors from varying process pressure and temperature. Known radar process control instruments operate at frequency bands of approximately 6 GHz or 24 GHz.
A through air radar measurement instrument must convert a high frequency electrical signal to an electromagnetic wave. A conventional device for accomplishing this is an exciter element or loop launcher housed in a waveguide. A loop launcher is a wire which couples energy from a coaxial feeder cable into the waveguide. Problems can occur in creating impedance matching between the coaxial cable and a required propagating mode, such as the TE11 mode. An antenna, such as a dielectric rod or horn, is operatively associated with the waveguide. An ultra-high frequency radiation beam is propagated downward from the antenna, and reflected off the surface of the material being measured to the antenna where the signal is received. The product level is calculated from the total time of propagation of the beam.
Typically, the antenna, waveguide and like components are provided as a unit and installed in a process vessel. If it is necessary to service the electronics, launcher or waveguide, then the device must be removed which disturbs the process seal. This can be problematic, particularly in hazardous process environments.
A difficulty can be encountered when a metal object is located in or around the radiated electromagnetic field. A reflection from a metal object can cause a false target situation, in which the system evaluates the product to be at a level indicated by the reflected signal from the object and not from the actual product. Typical false target objects in tanks are mixers, nozzles, ladders and tank walls. The radiated electromagnetic field distribution can be asymmetric about its centerline, and the pattern may vary along the direction of propagation. This phenomenon can be used as an advantage against false target detection. A signal level from a false target can vary as the antenna is rotated about its vertical axis. More specifically, the orientation of the loop launcher in the waveguide determines the sensitivity of the system to a false target. Optimization of the launcher position, as by rotating the device about the vertical axis, can minimize the effect of false targets.
The present invention is directed to overcoming one or more of the problems discussed above, in a novel and simple manner.


A control framework generates control parameters for controlling operation of a physical system, and includes one or more embedded models each producing a model output corresponding to a different operating parameter of the system as a function of one or more system operating conditions and/or a number of solution parameters, objective logic producing a scalar performance metric as a function of the number model outputs and of one or more system performance target values, objective optimization logic determining a number of unconstrained solution parameters in a manner that minimizes the scalar performance metric, and solution constraining logic determining the number of solution parameters from the number of unconstrained solution parameters in a manner that limits an operating range of at least one of the unconstrained solution parameters. The control parameters may correspond to one of the number of unconstrained solution parameters or to the number of solution parameters.

It is desirable to minimize the calibration burden that often accompanies existing implementations of both open and closed loop control strategies. It is further desirable to configure model-based control strategies such that improved models, in terms of accuracy and/or performance, may be simply substituted for corresponding existing models in the control strategies to achieve immediate system performance improvements. It is still further desirable to provide for optimization of the performance of physical systems under off-nominal operating conditions, i.e., under operating conditions outside those for which existing control strategies are specifically designed. The model-based control framework concepts described herein are directed to achieving these and other control strategy goals.

Framework for generating model-based system control parameters


A metal pivot pin for a timepiece movement includes at least one pivot at at least one of ends thereof, the metal is an austenitic steel, an austenitic cobalt alloy or an austenitic nickel alloy to limit sensitivity of the pin to magnetic fields, and at least an outer surface of the at least one pivot is hardened to a predetermined depth relative to a core of the pin. A method of fabricating a pivot pin includes forming the pivot pin from a base of austenitic steel, an austenitic cobalt alloy or an austenitic nickel alloy, to limit sensitivity of the pin to magnetic fields, including at least one pivot at one end of the pin, and diffusing atoms to a predetermined depth at least on an outer surface of said at least one pivot to harden the pivot in main areas of stress while maintaining a high roughness.

The manufacture of a pivot pin for a timepiece consists in performing bar turning operations on a hardenable steel bar to define various active surfaces (shoulder, projecting portion, pivots, etc.) and then in subjecting the bar-turned pin to heat treatments including at least one hardening operation to improve the hardness of the pin and one or more tempering operations to improve the roughness. The heat treatment operations are followed by an operation of rolling the pin pivots, which consists in polishing the pivots to the required dimensions. The rolling operation also improves the hardness and the roughness of the pivots. It will be noted that this rolling operation is very difficult or even impossible to achieve with materials having a low hardness, i.e. less than 600 HV.
The pivot pins, for example the balance staffs, conventionally used in mechanical timepiece movements are made in grades of bar turning steel which are generally martensitic carbon steels including lead and manganese sulphides to improve their machinability. A known steel of this type, designated 20AP, is typically used for these applications.
This type of material has the advantage of being easy to machine, in particular of being suitable for bar turning and, after hardening and tempering, has superior mechanical properties which are very advantageous for making timepiece pivot pins. These steels have, in particular, superior wear resistance and hardness after heat treatment. Typically, the hardness of pin pivots made of 20AP steel can exceed 700 HV after heat treatment and rolling.
Although this type of material provides satisfactory mechanical properties for the timepiece applications described above, it has the drawback of being magnetic and able to disrupt the working of a watch after being subjected to a magnetic field, particularly when the material is used to make a balance staff cooperating with a balance spring made of ferromagnetic material. This phenomenon is well known to those skilled in the art and is for example described in the Bulletin Annuel Suisse de Chromométrie Vol. I, pages 52 to 74. It should also be noted that these martensitic steels are also corrosion sensitive.
Attempts have been made to overcome these drawbacks with austenitic stainless steels which have the peculiarity of being non-magnetic, i.e. paramagnetic or diamagnetic or antiferromagnetic. However, these austenitic steels have a crystallographic structure which means that they cannot be hardened or achieve hardnesses and thus wear resistances compatible with the requirements necessary for making timepiece pivot pins. One means of increasing the hardness of these steels is cold working; however this hardening operation cannot achieve hardnesses of more than 500 HV. Consequently, for parts which require high resistance to wear due to friction and pivots which have little or no risk of deformation, the use of this type of steel remains limited.
Another approach for attempting to overcome these drawbacks consists in depositing on the pivot pins hard layers of materials such as diamond-like-carbon (DLC). However, there have been observed significant risks of delamination of the hard layer and thus the formation of debris which can move around inside the watch movement and disrupt the operation of the timepiece, which is unsatisfactory.
Yet another approach has been envisaged for overcoming the drawbacks of austenitic stainless steels, namely the superficial hardening of the pivot pins by nitriding, carburizing or nitrocarburizing. However, these treatments are known to cause a significant loss of corrosion resistance because of the reaction of the nitrogen and/or carbon with the chromium in the steel and the formation of chromium nitride and/or chromium carbide causing localised depletion of the chromium matrix, which is detrimental to the desired timepiece application.


A track maintenance machine for excavating material from a track bed comprises a machine frame comprising an upwardly recessed machine frame section, undercarriages supporting the machine frame on the track for movement in an operating direction, and sequentially arranged on the machine frame in the operating direction, a ballast receptacle comprising chutes for discharging the ballast from the receptacle, an inclined, vertically adjustable and revolvable endless excavating chain comprising a drive at an upper end for revolving the chain, the excavating chain being mounted underneath the upwardly recessed machine frame section for excavating the material from the bed, a track lifting device, a conveying arrangement arranged to remove the received excavated material and having an inlet end arranged below the upper excavating chain end to receive the excavated material therefrom, the ballast discharging chutes being arranged immediately behind the conveying arrangement inlet end in the operating direction, and a ballast clearing device mounted underneath the upwardly recessed machine frame section and comprising ballast clearing tools and drives for adjusting the ballast clearing tools vertically and transversely to the longitudinal direction. The track lifting device is arranged between the excavating chain and the ballast clearing device.

1. Field of the Invention
present invention relates to a track maintenance machine for excavating material from a bed supporting a track including rails, which comprises a machine frame extending in a longitudinal direction and comprising an upwardly recessed machine frame section, undercarriages supporting the machine frame on the track for movement in an operating direction, and sequentially arranged on the machine frame in the operating direction, a ballast receptacle comprising means for discharging the ballast from the receptacle, an inclined, vertically adjustable and revolvable endless excavating chain having an upper end and comprising a drive at the upper end for revolving the chain, a track lifting device, and a conveying arrangement arranged to remove the received excavated material and having an inlet end arranged below the upper excavating chain end to receive the excavated material therefrom.
2. Description of the Prior Art
U.S. Pat. No. 5,553,674 discloses a ballast cleaning machine comprising a vertically adjustable endless excavating chain revolvable around the machine frame and delivering the excavated ballast to a screening arrangement for cleaning. A ballast storage car may be connected to the rear end of the ballast cleaning machine so that additional clean ballast stored in the car may be used for preparing a new ballast bed. A vertically and transversely adjustable suction pipe is arranged ahead of the excavating chain, in the operating direction, to aspirate ballast ahead of the excavating chain. In this way, a gap is created in the ballast bed to enable the transverse excavating chain strand to be inserted underneath the track.
Another track maintenance machine has been disclosed in U.S. Pat. No. 5,257,580. It serves for the excavation of material from a track bed, in conjunction with producing a protective layer on the subgrade of a track. To enable a large volume of ballast to be excavated, the revolvable excavating chain is of large dimension and its upper portion is revolved around the machine frame, for which reason the machine frame must have a section of correspondingly reduced transverse dimensions to permit the excavating chain to be revolved therearound. This increases the cost of production of the machine frame. A ballast storage receptacle is mounted on the rear end of the machine frame to enable additional ballast to be continuously delivered to the operating site while the encrusted ballast is excavated and a conveying arrangement removes the excavated ballast to a storage car preceding the machine in the operating direction. An undercarriage with four axles precedes the excavating chain in the operating direction and is displaceable in the longitudinal direction of the machine frame to enable the track to be lifted sufficiently to enable the large excavating chain to be operated without difficulty.
Finally, it is known from U.S. Pat. Nos. 4,357,874 and 4,502,389 to use a ballast excavating chain mounted underneath an upwardly recessed machine frame section in conjunction with the removal of track sections from the track. The machine frame must be longer than the track sections to be removed and the wheel base must be correspondingly wide.

Franz Plasser Bahnbaumaschinen-Industriegesellschaft m.b.H.


An elevator limit switch is constructed of molded plastic box and lid and is readily adaptable for left side or right side use on an elevator or an elevator hoistway. The box and lid hold a one piece plastic hub which carries a mounting system for holding readily reversible electrical contacts.

Elevator equipment is located in either hoistway or the machine room. In addition to a car, counterweight, and ropes, the hoistway contains many components that are essential to the safety and performance of the elevator. These include car and counterweight guide rails, pit equipment, a car position reader, hoistway doors, and top and bottom terminal landing limit switches.
Limit switches are mounted on brackets attached to car guide rails at the top and bottom terminal landings in the hoistway. The limit switches are actuated ("opened") by a cam that rides with the car to ensure that the car does not collide with the overhead hoistway structure or compress the elevator buffer.
In a typical mid-rise installation, four limit switches are located at each terminal landing. The first two are slowdown limit switches that are opened before the car reaches the landing. A third limit switch is located at the landing and opens to provide a signal to prevent further travel of the car beyond the landing. A fourth and final limit switch is opened when the car passes the terminal landing and provides a signal to prevent all further travel in either direction.
In some high-rise, high-speed installations, the switches may be mounted on the car. The switches are opened sequentially by cams located at the top and bottom terminal landings.
Existing elevator limit switches have an abundance of parts, are noisy due to the backlash inherent in the assembled parts, are difficult to assemble, inclined to rust, and relatively vulnerable to dust or water.


A keyboard for an electronic device that incorporates a flexible carrier for the keys. The flexible carrier has cutouts or slots that aid in decoupling the actions of one from its neighbors. Moreover, in addition to or instead of cutouts or slots, the flexible carrier optionally has cutouts around its outer perimeter. In some embodiments, the keys are molded as part of the flexible carrier. In other embodiments, the keys are attached to or inserted in the flexible carrier during manufacture. Various embodiments of the invention employ various key shapes to aid the user's tactile experience while typing.

1. Field of the Invention
This application pertains generally to keyboards for electronic devices and more specifically to keyboards for handheld electronic devices.
2. Description of Related Art
As electronic devices shrink, their keyboards are being designed to be correspondingly smaller in size. Smaller keyboards have keys physically closer to one another and have associated problems with tactile feel and key bounce. Conventional keyboards often use unitary keys and an associated actuator located under the keys. Smaller keyboards sometimes use other types of molded keys. If a small keyboard has molded keys spaced close together, the keys are often coupled to each other in some manner. Thus, pressing on one molded key pulls on its neighbors, adversely affecting the user's tactile feedback.
Moreover, use of smaller keys often leads to the use of smaller snap domes under the keys. These smaller domes have a lower snap ratio and therefore adversely affect the user's tactile experience.
What is needed is a keyboard that minimizes key bounce and improves the feel of the keyboard for the user. The actions of the keys should be decoupled from each other as much as possible. In addition, it is desirable that the keyboard be small but that the user still be able to type quickly and locate keys by touch.

Method and apparatus to improve tactile feel for keyboards and button assemblies


In order to provide an exhaust gas purifying catalyst having improved heat resistance and OSC, a metal oxide particle, and a production process of the metal oxide particle, a metal oxide particle having a core (1) where the total molar number of alumina and silica is larger than the molar number of ceria, and a surface layer (2) where the molar number of ceria is larger than the total molar number of alumina and silica is provided. Further, an exhaust gas purifying catalyst comprising the metal oxide particle and a noble metal supported on the metal oxide particle; and a production process of the metal oxide particle are provided.

The exhaust gas from internal combustion engines such as automobile engine contains nitrogen oxide (NOx), carbon monoxide (CO), hydrocarbon (HC) and the like, and these substances are purified by an exhaust gas purifying catalyst and then released into air. As a representative exhaust gas purifying catalyst used therefor, a three-way catalyst where a noble metal such as platinum (Pt), rhodium (Rh) and palladium (Pd) is supported on a porous metal oxide carrier such as γ-alumina is known.
In order to allow for efficient progress of oxidation of CO and HC and reduction of NOx by the activity of the three-way catalyst, the air-fuel ratio in the internal combustion engine must be a theoretical air-fuel ratio (stoichiometric ratio). When the internal combustion engine is operated in the condition of excess air for fuel (lean) or in the condition of excess fuel for air (rich), the three-way catalyst cannot satisfactorily exert its purifying effect.
Therefore, for absorbing the fluctuation of oxygen concentration in the exhaust gas and thereby elevating the exhaust gas purifying capacity of the three-way catalyst, a material having an oxygen storage capacity (OSC) for storing oxygen when the oxygen concentration in the exhaust gas is high, and releasing oxygen when the oxygen concentration in the exhaust gas is low, is used for the exhaust gas purifying catalyst. A representative material having OSC is ceria (CeO2).
It is known that the OSC of ceria is enhanced when ceria is used together with zirconia to form a ceria-zirconia composite oxide (see, Japanese Unexamined Patent Publication No. 8-103650, 8-109020, 8-109021, 2000-319019, and 2001-89143). By this formation of ceria into a composite oxide, the heat resistance of ceria is improved, but sufficiently high heat resistance is not yet obtained.
In Japanese Unexamined Patent Publication No. 10-194742, zirconium hydroxide is used as the zirconia source for improving the heat resistance of the ceria-zirconia composite oxide.
In Japanese Unexamined Patent Publication No. 10-258232, a catalyst for exhaust gas purification having improved sulfur-poisoning resistance and heat resistance is provided. The catalyst comprises a core part made of alumina/titania complex oxide and NOx storage material, and a catalyst-carrying layer thereon made of a metal oxide complex comprising alumina and a catalytic noble metal.
The present invention provides an exhaust gas purifying catalyst having OSC and an improved heat resistance, a metal oxide particle, and a production process of the metal oxide particle.
According to studies in recent years, it has been found that the ceria not only has OSC but also, by virtue of its strong affinity for platinum, prevents particle growth (sintering) of platinum supported on ceria and in turn reduction of the exhaust gas purifying capacity. Therefore, if ceria is used in the form of a ceria-zirconia composite metal oxide as in conventional techniques, the platinum is randomly supported on both ceria and zirconia constituting the composite metal oxide surface, and the ceria cannot fully exert its ability of preventing platinum from sintering.
The present invention provides an exhaust gas purifying catalyst and metal oxide particle, having an effect of preventing platinum from sintering as well as heat resistance and OSC, and a production process of the metal oxide particle.
Incidentally, the above-described problems are partially solved also by the zirconium particle having a ceria surface which is proposed by the present inventors in Japanese Unexamined Patent Publication No. 2004-141833 (published after the priority date of the present application).

Exhaust gas purifying catalyst, metal oxide particle and production process thereof


A sluice box separator apparatus having a curved partition wall to shape the water flow into a horizontal vortex, inducing lighter material to exit the vortex with the water, and the denser materials to settle into a well located beneath the location of the induced vortex, including a selectively openable gate between the well and a valuable material recovery chamber.

1. Field of the Invention
This invention generally relates to the field of gold or gem mining, and more specifically to continuous flow sluice boxes.
2. Description of the Related Art
A number of methods are typically used to mine gold and gems from the earth's surface. In this disclosure, the material being mined will be referred to simply as "gold," but other heavy metals, valuable materials and gems may still be includable in that term. This disclosure will also use the term "deposit material" to refer to the mix of gold and non-gold naturally found at a mining site. The simplest technique to separate gold from the non-gold material is panning. In panning some deposit material is placed in a large plastic or metal pan, along with a generous amount of water. The pan is then agitated so that the gold particles, being of higher density than the non-gold material, settle to the bottom. The non-gold material is flushed from the pan with the water, leaving the desired gold left in the bottom of the pan. Concentric, circumferential ribs are frequently added to the sides of the pan to provide additional low spots for the gold to settle during agitation.
The agitation in a pan can be circular or linear, and is caused by the motion of the pan in the hands of the miner. The waves created by the motion accelerate the non-gold particles, and keep them suspended, while the denser settle to the low spots in the pan.
Sluice boxes and rocker boxes work on a similar principle, just on a slightly larger scale. Rocker boxes tend to be slightly smaller, and both the deposit material and water are generally fed by hand. Improvements include using a filter blanket on the bottom of the box to capture the fine pieces of gold. Sluice boxes, as their name implies, are fed by a sluice, or water flow. Parallel ridges on the bottom of the sluice box, perpendicular to the flow of water, trap the heavier gold particles as the water washes them, while the non-gold material is removed with the water. The pitch of the sluice box and the rate of the water flow can be adjusted to optimize capture of the particular size of gold particles in the deposit material.
The side to side agitation of the rocker box, and the latter will slow agitation of the sluice box, both are seen to create horizontal swirls, or vortices, that agitate the deposit material. The non-gold material is accelerated in the swirled flow, and thereby continues to be suspended in the swirling water. The gold, however, because it is being denser, resists the swirling motion and settles in the low spots in the boxes.
It would be a valuable addition to the prior art to have a sluice box that avoids horizontal sluice riffles and matting, which rely on a horizontal vortex. Horizontal vortices easily become overloaded with heavy material and allow the loss of desired materials. Additionally, horizontal vortices at high flow rates can accelerate even the desired heavy material, such as gold, ejecting it with the runoff water. Further, traditional sluices require suspension of operation and dismantling in order to recover the collected gold, or clean the box after an overload. Such an addition, embodied in the current disclosure, lead to increased feed rates of material, optimum material separation and collection. Additionally, collection can be achieved while running the sluice box or if the box can be automated. Further, the current disclosure permits the owner to configure a sluice box system to secure gold laden collected materials in a locked container for periodic retrieval by authorized individuals.

Vertical vortex generating sluice/slurry separator


An adjusting device for adjusting a motor vehicle seat is provided. The adjusting device includes an engagement fitting unit, a force transmission device configured to transmit a force for locking and unlocking the engagement fitting unit, and a force step-up transmission device configured to step up the force transmitted by the force transmission device. A motor vehicle seat, a motor vehicle, and a method for adjusting a motor vehicle seat using the adjusting device are also provided.

From the prior art, motor vehicles having seats are known, with which the position of the backrest, in particular with respect to a seat part, can be adjustable. The adjustment is effected via a lever mechanism arranged on the seat or another actuating device fixed there. Here, stepless adjustments by means of actuators and discontinuous adjustment, i.e. step-by-step adjustment by means of mechanical solutions are known. With the mechanical adjustments, locking or arresting devices for locking or for arresting have to be released or arrested for adjusting. This is effected via a lever, via which a force is transmitted to an engagement fitting. A force transmission in this case takes place proportionally, i.e., a force to be transmitted increases with the lever distance or in the case of a pivot movement, the torque increases with the twisting angle. Because of intermediate positions of the engagement fittings, adjusting is possible even with an engagement fitting not fully unlocked. In the case of adjusting in intermediate positions, undesirable side effects such as noise development during adjusting or increased wear occur.
From DE 38 00 924 C2 a vehicle seat having an adjusting device for a backrest is known. The adjusting device consists of a fixed-location bearing pedestal and a pivot arm pivotably mounted on the bearing pedestal, which is fastened to the backrest and can be fixed in selectable angular positions by means of a locking device. The adjusting device is covered by a covering part in the direction of the seat user. The bearing pedestal is fastened to the seat part and the remaining parts of the adjusting device are arranged within the backrest and connected with the latter. The covering part is connected with the latter. The covering part is connected to a part of the adjusting device in a fixed manner and comprises a slit into which a region of the bearing pedestal projecting upwards dips when the backrest is folded forward.
The actuating device for the known adjusting device is directly arranged on the seat to be adjusted. The arrangement of the actuation is relatively un-ergonomical and accessible only with difficulty in cramped conditions. In addition, an adjusting characteristic of the adjusting device is unfavourable for the user.
It is therefore at least one object herein to provide a solution which provides a simpler and more comfortable adjusting possibility. It is at least one object herein, in particular, to provide a motor vehicle, a motor vehicle seat, an adjusting device and a method thereto, with which the operating comfort for adjusting a seat is improved. In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.

Adjusting device for adjusting a motor vehicle seat, motor vehicle seat, motor vehicle and method for adjusting a motor vehicle seat


An NMR spectrometer comprising an NMR magnet system (27) disposed in a helium tank of a cryostat and an NMR probe head (11) disposed in a room temperature bore of the cryostat, which contains a cooled RF resonator (9) for receiving NMR signals from a sample to be investigated, and a cooled pre-amplifier (10), wherein the NMR probe head (11) is cooled by a common multi-stage compressor-operated refrigerator (2), wherein the refrigerator (2) comprises a cold head and several heat exchangers (5, 6) at different temperature levels, wherein the refrigerator (2) is disposed at a spatial separation from the cryostat in a separate, evacuated and thermally insulated housing (1) and wherein at least one cooling circuit with cooling lines, which are thermally insulated by a transfer line (13, 14) is disposed between the housing (1) containing the heat exchangers (5, 6) and the NMR probe head (11), is characterized in that additional cooling lines to an LN2 tank (18) or radiation shield (21) disposed in the cryostat and surrounding the helium tank are provided, and the refrigerator (2) also cools the LN2 tank (18) or the radiation shield (21). The inventive NMR spectrometer comprises a simple and inexpensive device for matching the holding time of LN2 to that of LHe through cooling the LN2 tank using the refrigerator provided for cooling the NMR probe head and without great expense.

The invention concerns an NMR spectrometer with an NMR magnet system disposed in the helium tank of a cryostat, and with an NMR probe head disposed in a room temperature bore of the cryostat which contains a cooled RF resonator for receiving NMR signals from a sample to be examined, and with a cooled pre-amplifier, wherein the NMR probe head is cooled by a common multi-stage compressor-operated refrigerator, the refrigerator comprising a cold head and several heat exchangers at different temperature levels, wherein the refrigerator is disposed at a spatial separation from the cryostat in a separate, evacuated and thermally insulated housing, and wherein at least one cooling circuit is provided comprising cooling lines, which are thermally insulated by a transfer line, extending between the housing containing the heat exchangers and the NMR probe head.
A device of this type is disclosed in U.S. Pat. No. 5,889,456.
The NMR probe head of an NMR spectrometer is located together with a measuring device in the bore of a magnet cryostat. This magnet cryostat houses a superconducting coil which generates the magnetic field required for the NMR measurements. The NMR probe head as well as the magnet cryostat must be kept at very low temperatures during operation. The thermal loss generated through thermal conduction and thermal radiation is therefore a problem.
Two important fields of application of cryocooling systems in the field of NMR are therefore cooling of the cryo probe heads for cryogenic cooling of the RF resonator and of the pre-amplifier and for cooling the superconducting NMR magnets for cryogenic cooling of the cryostat and therefore realization of a zero evaporation rate both for LN2 and LHe (LN2=liquid nitrogen, LHe=liquid helium).
Different systems from different companies are on the market today which are designed to solve this problem. The company JASTEC (Japan) [1] provides a cooling system for cooling the LN2 region of a cryostat for superconducting magnet systems up to 400 MHz. It contains a low-vibration pulse tube cooling unit which, however, has a maximum cooling power of less than that of conventional GM cooling units (GM=Gifford-McMahon). A zero evaporation rate for LN2 is therefore achieved only for NMR magnet systems of up to at most 400 MHz.
The company NIHON THERMAL (Japan) [2] provides a cooling system for cooling the LN2 region of a cryostat for superconducting magnets up to 600 MHz. It contains a powerful GM unit which generates stronger vibrations than that of JASTEC but provides a zero evaporation rate for LN2 at 600 MHz magnet systems.
There are conventional superconducting NMR magnets made by the company OXFORD INSTRUMENTS SUPERCONDUCTIVITY (GB) [3], which comprise a cooling system for cooling the LH2 and the LHe regions of the cryostat. The cooling system utilizes a low-vibration pulse tube cooling unit which is directly mounted to the cryostat and achieves a zero evaporation rate both for LN2 and for LHe.
The company Bruker BioSpin AG [4] and the company VARIAN (USA) [5] each distribute a cooling system called "CryoPlatform" (Bruker BioSpin) and "Cryo Bay" (Varian) for cryogenic cooling of RF resonators. These two cooling systems contain a GM cooling unit and use cold He gas as transport and cooling means.
U.S. Pat. No. 5,889,456 discloses a device comprising a refrigerator for cooling the NMR probe head. Heat exchangers and a transfer line from the refrigerator to the NMR probe head transfer the cooling power produced by the refrigerator. The NMR probe head is supplied with coolant by pumps or compressors via the transfer lines. The cooled components of the probe head are usually at temperatures of 10–60 Kelvin. A Gifford-MacMahon cooler (GM) or a pulse tube cooler (PT) are usually used as refrigerators.
In the majority of NMR magnet systems without active cryocooling, the holding time for LHe is more than 6 months, however, only two to three weeks for LN2. The short holding time for LN2 is due to cryostat construction only and applies as long as no excessive expense is incurred for thermal shielding of the LN2 tank.
The LN2 loss is on the order of magnitude of 10–20 Watt at approximately 77K which could be easily compensated for with a small active cooling unit. Small units with low power also require different basic units such as e.g. compressors, and are therefore not inexpensive. The expense required to solve only the object of reducing or completely compensating for the LN2 loss may therefore often be too high.
It is therefore the underlying purpose of the invention to propose an NMR spectrometer which permits matching of the holding time of LN2 to that of LHe without great expense to reduce the service costs associated with refilling the cryogenic liquids.

NMR spectrometer with refrigerator cooling