A halogenated polyamide acid composition containing a halogenated polyamide acid, a metal oxide precursor, a catalyst of reaction of generating a metal oxide from the precursor, and/or a coupling agent having a reactive group. A halogenated polyimide film is obtained by, for example, carrying out the heat treatment of the halogenated polyamide acid composition. The halogenated polyimide film has a refractive index at wavelength of, for example, 1,550 nm of 1.520 or lower. Further, an optical waveguide uses the halogenated polyimide film as at least one of a core layer and a clad layer, and a relative refractive index difference between the core layer and the clad layer of the optical waveguide is, for example, 0.6 or greater. An optical waveguide device contains such an optical waveguide.

1. Field of the Invention
The present invention relates to a halogenated polyamide acid composition, a halogenated polyimide film obtained therefrom, an optical waveguide, and an optical waveguide device.
2. Description of the Related Art
Technologies with respect to an optical waveguide as its basic component have been marked in accordance with the practical use of an optical communication system. The optical waveguide typically has an embedded type structure in which a clad layer with a low refractive index surrounds a core layer with a high refractive index, or a ridge type structure in which a core layer with a high refractive index is formed on a lower clad layer with a low refractive index and an upper clad layer is made of an air layer, and light injected into the optical waveguide is transmitted in the core layer while being reflected on the interface between the core layer and the clad layer or on the interface between the core layer and the air layer.
As the material to form an optical waveguide, there have been known inorganic materials such as quartz glass and semiconductor. On the other hand, the research and development of producing an optical waveguide with various polymers have been carried out. Since coating and heat treatment can be carried out for polymers as organic materials under normal pressure at a film forming step contrary to the inorganic materials, there is an advantage that its apparatus and production steps can be simplified.
As the material of a polymer optical waveguide, a poly(methyl methacrylate) (PMMA) has ordinarily been used because of its high optical transparency. In addition to it, polyimides have particularly been expected because they have high glass transition temperatures (Tgs) and excellent thermal resistance and they can endure heat at soldering. However, in the case of an ordinary polyimide, since the C—H bonds of a benzene ring absorb near infrared light in a near infrared region (at a wavelength of from 1,000 to 1,700 nm) used for optical communication, the deuteration and fluorination of hydrogen atoms are necessary for securing optical transparency. For example, the Japanese Patent Application Laid-Open (JP-A) Nos. 3-72528, 4-328504, 2004-85937, and 2005-37841, and the Japanese Patent (JP-B) No. 2816771 disclose various fluorinated polyimides useful for the material of a polymer optical waveguide.
By the way, as described above, it is required to provide a relative refractive index difference between the core layer and the clad layer in the optical waveguide. Accordingly, for example, in the Japanese Patent Application Laid-Open (JP-A) Nos. 3-72528, and 4-328504, and the Japanese Patent (JP-B) No. 2816771, polyimides different in molecular chain skeleton are selected as the materials of both layers, or only the core layer is formed with a fluorinated polyimide and a material (e.g., a silicon oxide film or an air layer) other than polymers is used for the clad layer. In contrast, in the Japanese Patent Application Laid-Open (JP-A) Nos. 2004-85937 and 2005-37841, the core layer and the clad layer are formed with a fluorinated polyimide having basically the same molecular chain skeleton and a relative refractive index difference is provided by changing the fluorine contents of both layers.
Further, for example, the Japanese Patent Application Laid-Open (JP-A) No. 4-8734 discloses a method of controlling a relative refractive index difference by copolymerizing two kinds of fluorinated polyimides and adjusting the fluorine content of the resulting copolymer, and the Japanese Patent Application Laid-Open (JP-A) No. 6-51146 discloses a method of controlling a relative refractive index difference by irradiating electron beam to a fluorinated polyimide and adjusting its exposure dose.
However, these methods change the molecular chain skeleton of a fluorinated polyimide, control the fluorine content of a fluorinated polyimide, carries out the copolymerization of fluorinated polyimides, and carries out the irradiation of electron beams to a fluorinated polyimide, and therefore, they have problems that: they can be applied to only a fluorinated polyimide having a specific molecular structure; a large scale apparatus and complicated producing steps are required; and the like.
Thus, the Japanese Patent (JP-B) No. 3486325 discloses a method of obtaining partially fluorinated polyimide having a lowered refractive index by adding silica ultrafine particles to a partially fluorinated polyamide acid as a precursor, followed by heat treatment, as a method of simply controlling a relative refractive index difference using an ordinary fluorinated polyimide. Since the refractive index of quartz glass is about 1.45, it lowers a refractive index without lowering an optical transparency by dispersing silica ultrafine particles in a partially fluorinated polyimide.
However, the method of the Japanese Patent (JP-B) No. 3486325 has a problem that productivity is extremely bad because it is necessary to stir a mixture for 24 hours in order to improve dispersibility after adding a dispersed solution of silica ultrafine particles to a solution of a partially fluorinated polyamide acid.
By the way, the Japanese Patent Application Laid-Open (JP-A) No. 8-73739 discloses a production method of a polyimide composition in which silica particles are ultrafinely dispersed, characterized in that in the production method of a polyimide composition by which an alkoxysilane and/or its partially hydrolyzed condensate is reacted with a polyamide acid in the presence of water and polyimidation is subsequently carried out, the reaction is carried out in the presence of an acid catalyst and/or an amino group containing alkoxysilane. In this method, silanol is generated by the reaction of an alkoxysilane and/or its partially hydrolyzed condensate with water and a transparent polyimide composition (e.g., a polyimide film or sheet) having an excellent elastic modulus is provided by ultrafinely dispersing silica particles prepared from the silanol in the following heating step.
However, the Japanese Patent Application Laid-Open (JP-A) No. 8-73739 fails to disclose or suggest using a halogenated polyamide acid in place of a polyamide acid and is completely silent on drastically chaining a refractive index by ultrafinely dispersing silica particles while securing the appearance and transparency of the obtained halogenated polyimide film. Further, the polyimide composition disclosed in the Japanese Patent Application Laid-Open (JP-A) No. 8-73739 is described as useful for applications such as electronic materials, forming materials such as films and sheets, and coating materials, but not described as useful for optical materials.

Halogenated polyamide acid composition and its applications


The linearity of a transmission signal is improved in a wireless communication device by adjusting a delay difference between paths of two signals that are combined into one after modulation through the paths of different delay amounts, such as an r signal and a θ signal in EER. A transmitter includes: a DA converter unit which converts, into analog signals, separated input digital signals; a combiner which combines the analog signals obtained through the DA conversion with each other; an distributor which extracts a feedback signal; an AD converter which converts the feedback signal into a digital signal; an oscillator unit which supplies clock signals to the converters; a first separation unit which separates the feedback signal; and a comparator unit which compares the input signal and the feedback signal, wherein the oscillator unit controls the output clock signals based on a result of the comparison.

This invention relates to a wireless transmitter/receiver having a function of adjusting, by way of closed-loop feedback control, the timing of a transmission signal. In particular, the invention relates to a wireless transmitter/receiver that employs EER to adjust the timing of sending an r (amplitude) component and a θ (phase) component.
For transmitters installed in base stations and terminals of cellular phone and other wireless communication systems, methods have been developed to separate a transmission signal into two components, process the two separately, and then recombine them as a transmission output. Known examples of such methods include one in which a transmission signal is separated into an I signal and a Q signal to be processed separately, and EER (Envelope Elimination and Restoration) in which a transmission signal is separated into an r (amplitude) component and a θ (phase) component to be processed separately.
However, signals created by separating one signal into two components to be processed separately differ from each other in signal propagation delay time in the case where processing circuits of the two components are arranged to present different signal path lengths. The separated signals could also differ from each other in signal processing time if different processing circuits are used to process the two. These result in disordered timing of recombining the separated signals into one signal and lowered quality of the recombined signal.
In EER, an r signal and a θ signal are combined, after receiving supply voltage modulation and frequency conversion, respectively, into one signal by a saturated power amplifier, which has high efficiency (see Je-Kuan Jau, "Linear Interpolation Scheme for Compensation of Path-Delay Difference in an Envelope Elimination and Restoration Transmitter", pp 1072-1075, Proceedings of APMC2001). The power consumption of a power amplifier which amplifies a transmission signal in a communication device constitutes a very large portion of the total power consumption of the communication device, and improving the power amplifier efficiency is a technical objective to be reached. EER addresses this objective by using a saturated power amplifier, which is high in efficiency, and is considered to be effective in reducing the size, cost and power consumption of a communication device.
A problem of EER is that it is liable to give r and θ signals different delay amounts from each other. While a supply voltage modulation circuit to process the r component is composed of, for example, a DC-DC converter, a frequency converter to process the θ signal is composed of a mixer or the like. Because of the vastly different circuit elements used by the two circuits, the delays caused in the process of signal processing mess up the timing of recombining the signals into one signal and greatly lower the quality of the recombined signal.
FIG. 7 is a waveform chart showing the principle of degradation in transmission signal quality due to delays of r and θ signals in EER.
When a sine wave is inputted to a transmitter that employs EER, the waveform of an amplitude component r (θ) 101 is that of a sine wave folded back along the x axis whereas a phase component p (θ) 102 forms a square wave. Normally, the folding back of the r (θ) 101 synchronizes with the phase inversion of the p (θ) 102. Here, consider the case where the phase inversion of the p (θ) 102 is behind the folding back of the r (θ) 101 by τ. A signal S (θ) 103, which is obtained by recombining these r (θ) 101 and p (θ) 102, experiences discontinuous phase inversions for the period τ, causing sharp peaks in an error signal u (θ) 104. This error signal component turns into spurious output (noise) and lowers the quality of the signal. In order to obtain a desired signal quality, the delay difference between the r signal and the θ signal somehow has to be adjusted to align the folding back and the phase inversion with each other.
FIG. 8 is a block diagram illustrating a conventional timing adjustment method for a wireless transmitter/receiver that employs EER. In FIG. 8, the amount of delay along a signal path for r (amplitude) 201 and the amount of delay along a signal path for θ (phase) 202 are made equal to each other by inserting a delay Δdd, which corresponds to the delay difference, Δdr minus Δdθ, to one of the paths where a delay caused by a circuit element is smaller (here, Δdr is larger than Δdθ and the delay Δdd is given to the θ side). It is a digital region where Δdd is inserted in FIG. 8 and, when Δdd is an integer multiple of the clock cycle, the adjustment can be made by simply delaying the θ signal by n clocks with the use of a shift register 203 or the like.
Usually, the delay scale is smaller than one clock and external factors such as a temperature variation make delay fluctuate with time. Je-Kuan Jau proposes a method of adjusting delay at a precision of ½ clock with the use of a digital filter, which performs a linear interpolation on a transmission signal. This structure uses, as FIG. 8 shows, a single master clock source 206 (fixed frequency) to drive digital-to-analog converters (DAC) 204 and 205 of the two paths.
Described next is an example of a timing adjustment method using a feedback (Fb) circuit for a wireless transmitter/receiver that employs other systems than EER.
FIG. 9 is a block diagram showing a timing adjustment method for a transmission signal and a feedback signal in a predistortion (distortion compensation) transmitter (see JP 2001-189685 A).
In FIG. 9, a feedback circuit 301 receives a signal that has been amplified by a power amplifier (PA) 302 and compares the amplified signal against the original transmission signal to measure the amount of nonlinear distortion caused along a transmission signal path (signal path for Tx) 303 including the power amplifier 302 and other elements. A pre-distortor co-efficient calculation unit 304 calculates a coefficient that gives a distortion of the reverse characteristic to cancel the non-linear distortion, and sets the obtained coefficient to a pre-distortor 305. The pre-distortor 305 applies a non-linear distortion determined by the set coefficient to the transmission signal, which is then sent to a frequency-conversion and amplifier unit 307 through a DAC 306.
Meanwhile, in order to align the transmission signal and the feedback signal with each other for comparison, a delay time calculation unit 308 detects the delay difference between the two and determines the amount of delay of a shift register 309 (Δd1) and the amount of delay of a variable delay element 310 (Δd2). The delay amount Δd1 of the shift register 309 corresponds to a delay for the transmission signal by an integer multiple of the clock cycle. The delay amount Δd2 of the variable delay element 310 corresponds to a delay on the 1/n clock-basis of the clock phase of an analog/digital converter (ADC) 311, which converts the feedback signal into a digital signal. In this structure, the same single master clock source is used to drive the DAC 306 and the ADC 311, and the clock phase of the master clock source is fixed.

Timing adjustment method for wireless communication apparatus

Hitachi Communication Technologies, Ltd.


A method for assisting in turning a vehicle, the method may include detecting or estimating that the vehicle is about to turn to a certain direction or is turning to the certain direction; sensing a relevant portion of an environment of the vehicle to provide sensed information, wherein the relevant portion of the environment is positioned at a side of the vehicle that corresponds with the certain direction; applying an artificial intelligence process on the sensed information to (i) detect objects within the relevant portion of the environment and (ii) estimate expected movement patterns of the objects within a time frame that ends with an expected completion of the turn of the vehicle; determining, given an expected trajectory of the vehicle during the turn and the expected movement patterns of the objects, whether at least one of the objects is expected to cross the trajectory of the vehicle during the turn; and responding to an outcome of the determining.

Vehicles perform multiple turns on a daily basis. A turn may be considered to be riskier than a straight segment of the road as the vehicle driver or an autonomous system that control the vehicle may not aware in advance of potential risks related to the turn.
There is a growing need to provide a secure manner of turning a vehicle.


A picture image processing apparatus is provided with a hue calculating portion for calculating a hue pixel by pixel based on RGB data, a first sampling portion for sampling pixels having a hue corresponding to a skin color from the RGB data, a first characteristic quantity calculating portion for calculating a first characteristic quantity representing a characteristic of the RGB data of the pixels, a second sampling portion for sampling the pixels located in a central part of an image area, a second characteristic quantity calculating portion for calculating a second characteristic quantity representing the RGB data of the pixels sampled by the second sampling portion, a correction amount calculating portion for calculating a density correction amount using the first and second characteristic quantities, and a density correcting portion for correcting the density of the RGB data. The density of a main subject in the image can be properly corrected.

This invention relates to a technique of correcting digital image data obtained by a scanner or a digital camera such that, particularly, a main subject has a proper density.
There is known an apparatus provided with a function of enabling a density correction to adjust the density of an outputted image, particularly main subject, to a proper level in the case of outputting a digital image obtained by a scanner or a digital camera to a monitor, a printer or the like.
A known method for this density correction is such that an average value of the density of the entire image data is obtained for each of the respective color components of R (red), G (green), B (blue) of the digital image data, and histograms of the respective color components R, G, B are corrected such that the density average values coincide with density reference values set beforehand.
In the case that the density correction is applied by the above method to an image having a skewed density distribution in the entire image such as an image obtained by photographing a human figure as a main subject against a bright background without using a flash device or an image obtained by photographing a human figure as a main subject against a dark background using a flash device, there has been a problem that the density of the human figure as the main subject cannot be properly corrected by being influenced by the background.
For instance, image data obtained by photographing a human figure as a main subject against a dark background using a flash device has a large density average value. Thus, if the density correction is applied to this image data by the above method, such a density correction as to reduce the entire density is applied, which makes the density of the human figure as the main subject excessively low. As a result, an output image having a proper density cannot be obtained.

Picture image processing apparatus and method, and picture processing system


One or more nanotaper coupling waveguides formed within an optical substrate allows for straightforward, reproducible offset launch conditions to be achieved between an incoming signal and the core region of a multimode fiber (which may be disposed along an alignment fixture formed in the optical substrate), fiber array or other multimode waveguiding structure. Offset launching of a single mode signal into a multimode fiber couples the signal into favorable spatial modes which reduce the presence of differential mode dispersion along the fiber. This approach to providing single mode signal coupling into legacy multimode fiber is considered to be an improvement over the prior art which required the use of an interface element between a single mode fiber and multimode fiber, limiting the number of propagating signals and applications for the legacy multimode fiber. An optical switch may be used to select the specific nanotaper(s) for coupling into the multimode fiber.

Fiber optic technology is playing an ever-increasing role in the modern age of communications. As communication standards such as Fibre Channel (1062 Mbps) and Gigabit Ethernet (1000 Mbps) place ever-increasing demands on the physical layer infrastructure, optical fiber is being looked to more and more as the transmission medium of choice. Advancements in optoelectronic devices have furthered the desirability of fiber-based arrangements, since these arrangements not only support the necessary high data transmission rates, but the cost is becoming more and more affordable.
A key aspect of the affordability is the modularity by which the advancements in optical fiber technology are being implemented, particularly with regard to their backward compatibility with existing network components, such as multimode fiber. Advancements that cannot be delivered to the marketplace with backward compatibility may not be as desirable as competing advancements which are backward compatible. For example, if an advancement requires recabling an entire building from multimode to single mode fiber, then it may not be a viable solution. If an advancement requires specialized equipment, connectors, patch cords and the like, then it too may not be a viable solution. Accordingly, a desirable feature of any new technological advancement is the modularity and/or compatibility with existing components.
One "legacy" aspect of fiber-based communication systems is their utilization of multimode fiber; that is, a fiber with a relatively large core area that is able to support a plurality of different spatial modes of a propagating optical signal. More recent systems have utilized smaller core, "single mode" fiber, such that when excited by a laser source, only a single spatial mode is supported. In one class of fiber optic communication systems—wavelength division multiplexed (WDM) systems—it is possible to use either multimode or single mode fiber. In particular, multimode fiber can be used with "coarse" WDM (CWDM) which utilizes wavelength spacing of approximately 20 nm. A multiplexer is still required in this system to combine the separate wavelengths into the single transmission fiber.
The extensive earlier deployment of multimode fiber has resulted in the need to, at times, provide coupling between multimode fiber and single mode fiber. Since each spatial mode in the multimode fiber has slightly different propagation characteristics, the coupling of a single mode signal into multimode fiber will inevitably result in spreading the propagating pulses in time (modal dispersion), limiting the useful bandwidth-distance product of the system. Arrangements for improving the bandwidth are considered to be desirable.
In some cases, electronic dispersion compensation (EDC) techniques have been used to correct for the presence of modal dispersion in a received signal. Generally speaking, EDC utilizes arrangements such as active filters to create a set of delayed samples of a received signal (once an optical-to-electronic conversion has been performed). The samples are thereafter scaled and reconstructed to form the original signal. Filtering such as Finite Impulse Response (FIR) or Feed Forward Equalization (FFE) have been found useful for this application. However, the need to include additional electronic components in an optical receiver is not an acceptable solution in some cases, particularly where the physical size and power requirements of the receiver are limited.
It has previously been shown that the bandwidth of a multimode optical fiber can be increased by launching optical signals from a single-mode optical fiber into the multimode optical fiber with a deliberate, predetermined offset between the central axis of the single-mode optical fiber and the central axis of the multimode optical fiber. This feature, referred to as an off-axis or offset launch condition, represents a significant advancement because it has the potential to extend the bandwidth of existing multimode optical fiber installations, such as in a local area network (LAN). By increasing the available bandwidth, the useful life of existing or new installations of multimode fiber may be lengthened. Without the ability to extend the bandwidth, different spatial modes supported by the legacy multimode fiber propagate with different modal group velocities, leading to temporal spreading of a propagating optical signal and thus limiting the speed at which data may be transmitted along this legacy type of fiber.
However, because the dimensions of the offset for an offset launch condition are so small (typically less than 30 μm), the launching single-mode fiber and the receiving multimode optical fiber need to be precisely aligned, preferably within a tolerance on the order of 4-8 μms. Two suggested methods for achieving this precise offset include: the use of a specialized patch cord that incorporates a desired level of offset, or the use of an adapter that precisely aligns the optical fibers so that their cores have a predetermined offset, as described in U.S. Pat. Nos. 6,273,619 and 6,402,390.
While these techniques have some merit, they generally require one or more specialized components or equipment for effectuating an offset launch condition at the fiber interface. Thus, there continues to exist an unsatisfied need in the industry for an optoelectronic module that can be coupled to a multimode optical fiber under an offset launch condition without utilizing specialized equipment or components.

Offset launch mode from nanotaper waveguide into multimode fiber


In a non-volatile semiconductor memory system (or other type of memory system), a memory cell is programmed by changing the threshold voltage of that memory cell. Because of variations in the programming speeds of different memory cells in the system, the possibility exists that some memory cells will be over programmed. That is, in one example, the threshold voltage will be moved past the intended value or range of values. The present invention includes determining whether the memory cells are over programmed.

1. Field of the Invention
The present invention relates generally to technology for memory devices and, more specifically, to detecting whether memory devices have been over programmed.
2. Description of the Related Art
Semiconductor memory devices have become more popular for use in various electronic devices. For example, non-volatile semiconductor memory is used in cellular telephones, digital cameras, personal digital assistants, mobile computing devices, non-mobile computing devices and other devices. Electrical Erasable Programmable Read Only Memory (EEPROM) and flash memory are among the most popular non-volatile semiconductor memories.
Typical EEPROMs and flash memories utilize a memory cell with a floating gate that is provided above and insulated from a channel region in a semiconductor substrate. The floating gate is positioned between source and drain regions. A control gate is provided over and insulated from the floating gate. The threshold voltage of the memory is controlled by the amount of charge that is retained on the floating gate. That is, the minimum amount of voltage that must be applied to the control gate before the memory cell is turned on to permit conduction between its source and drain is controlled by the level of charge on the floating gate.
Some EEPROM and flash memory devices have a floating gate that is used to store two ranges of charges and, therefore, the memory cell can be programmed/erased between two states. When programming an EEPROM or flash memory device, a program voltage is applied to the control gate and the bit line is grounded. Electrons from the p-well are injected into the floating gate. When electrons accumulate in the floating gate, the floating gate becomes negatively charged and the threshold voltage of the memory cell is raised.
Typically, the program voltage applied to the control gate is applied as a series of pulses. The magnitude of the pulses is increased with each pulse by a predetermined step size. In the periods between the pulses, verify operations are carried out. That is the programming level of each cell being programmed in parallel is read between each programming pulse to determine whether it is equal to or greater than a verify level to which it is being programmed. One means of verifying the programming is to test conduction at a specific compare point.
Conduction represents an "on" state of the device corresponding to the flow of current across the channel of the device. An "off" state corresponds to no current flowing across the channel between the source and drain. Typically, a flash memory cell will conduct if the voltage being applied to the control gate is greater than the threshold voltage and the memory cell will not conduct if the voltage applied to the control gate is less than the threshold voltage. By setting the threshold voltage of the cell to an appropriate value, the cell can be made to either conduct or not conduct current for a given set of applied voltages. Thus, by determining whether a cell conducts current at a given set of applied voltages, the state of the cell can be determined.
A multi-bit or multi-state flash memory cell is produced by identifying multiple, distinct threshold voltage ranges within a device. Each distinct threshold voltage range corresponds to predetermined values for the set of data bits. The specific relationship between the data programmed into the memory cell and the threshold voltage levels of the cell depends upon the data encoding scheme adopted for the cells. For example, U.S. Pat. No. 6,222,762 and U.S. patent application Ser. No. 10/461,244, "Tracking Cells For A Memory System," filed on Jun. 13, 2003, both of which are incorporated herein by reference in their entirety, describe various data encoding schemes. Proper data storage requires that the multiple ranges of threshold voltage levels of a multi-state memory cell be separated from each other by sufficient margin so that the level of the memory cell can be programmed or erased in an unambiguous manner.
In many cases it is necessary to program multiple memory cells in parallel, for example, in order to produce a commercially desirable memory system which can be programmed within a reasonable amount of time. However, a problem arises when a number of the memory cells are to be programmed at the same time. This is because the characteristics of each memory cell is different due to minor variations in the structure and operation of the semi-conductor devices which comprise the memory cells; therefore, variations in the programming speed of different cells will typically occur. This results in memory cells that become programmed faster than others and the possibility that some memory cells will be programmed to a different state than intended. Faster programming of multiple memory cells can result in over-shooting desired threshold voltage level ranges, producing errors in the data being stored.
Typically, when data is being programmed, the verify process for the device will guarantee that the threshold voltage of the memory cell is higher than a minimum level. However, devices typically do not guarantee an upper limit on the threshold voltage. Some devices do check to see if a soft programming process (described below) raised the threshold voltage too high; however, these devices do not check to see if a regular programming process raised the threshold voltage too high. Thus, over programming which raises the threshold voltage beyond the range for the desired state can occur without being noticed. Over programming can cause the memory cell to store incorrect data, thereby, causing an error during subsequent read operations. More information about over programming can be found in U.S. Pat. Nos. 5,321,699; 5,386,422; 5,469,444; 6,134,140 and 5,602,789.
To correct for over programming many memory systems use Error Correction Codes ("ECC") during subsequent read operations. When data is read from a device, the ECC is used to determine whether an error occurred. If the errors are small enough, the ECC can be used to correct the errors. However, at least three problems arise when using ECC to correct errors due to over programming. First, the ECC process requires a large amount of processing time and, therefore, considerably slows down the operation of the memory system. Second, ECC requires additional dedicated hardware to perform the ECC in a reasonable amount of time. Such dedicated hardware can take up a considerable amount of room on the memory system chips. The trend is to reduce the size of the memory systems in order to be able to put more memory cells in the system and to make the system as small as possible to fit in smaller host devices. Thus, new memory designs typically are reducing the amount of real estate that can be used for ECC. Third, if there are multiple errors, the ECC may not be able to correct the errors.
Thus, there is a need for an improved means to detect over programming of memory cells.


A semiconductor device includes a multiple layer structure including a substantially flat active layer, and a first semiconductor layer and a second semiconductor layer adjacent to each other, the semiconductor layers having a corrugation at an interface therebetween; and a generating device which is connected to the multiple layer structure. An electromagnetic field intensity distribution is generated by use of the generating device in a waveguide region including the active layer, and the active layer includes a gain distribution having a distribution pattern corresponding to the corrugation. The multiple layer structure is produced by forming the corrugation on an upper surface of the first semiconductor layer, and forming the rest of the multiple layer structure including the second semiconductor layer and the active layer by using a vapor phase growth method once so as to make the active layer substantially flat. Then, the generating device is formed to be in contact with the multiple layer structure.

1. Field of the Invention
The present invention relates to a semiconductor device including an optical device and an electron device and a method for producing the same. In particular, the present invention relates to an optical device such as an integrable wavelength-controlled semiconductor laser and also to a high speed and low power consumption electron device.
2. Description of the Prior Art
Recently, a distributed Bragg reflection (DBR) laser and a distributed feedback (DFB) laser have been developed. These types of lasers have excellent characteristics as a single longitudinal mode laser.
The wavelength of light reflected in parallel generated from parallel incident light in a diffraction grating is expressed by the formula: .lambda..sub.0 =2N.sub.eff .LAMBDA./m, where N.sub.eff is an equivalent refractive index, .LAMBDA. is the periodicity of the diffraction grating, and m is the order of the diffraction grating. In the DBR laser and the DFB laser, oscillation in a single longitudinal mode is realized by utilizing wavelength selectivity.
FIG. 9 is a schematic view of an AlGaAs DFB laser as an example of such known semiconductor lasers. The DFB laser shown in FIG. 9 is produced in the following manner. On a GaAs substrate 901, a cladding layer 902, an active layer 903, and an optical guide layer 904 are sequentially grown by a first epitaxial growth, and a diffraction grating 907 having a specific periodicity is formed on a surface of the optical guide layer 904. Then, a cladding layer 905 and a contact layer 906 are grown by a second epitaxial growth on the diffraction grating 907.
As is apparent from the above, in order to produce a semiconductor laser such as the one shown in FIG. 9, the epitaxial growth must be performed at least twice. Moreover, it is necessary to form a diffraction grating at a sufficiently close position to an active layer so that the diffraction grating can fully influence an optical field intensity distribution which is generated in the optical waveguide region including the active layer. In a semiconductor laser having such a structure, a non-radiative recombination center which is generated at the interface along the diffraction grating reduces the light emitting efficiency and the reliability of the laser. Moreover, freedom of design of device structure is restricted.
FIG. 10 is a schematic view of an InP DFB laser as another example of known semiconductor lasers. In the InP DFB laser, as distinct from the AlGaAs DFB laser, no oscillating light is absorbed into the substrate. Therefore, it is possible to form a diffraction grating 1006 on a substrate 1001. Accordingly, the rest of the multiple layer structure including an optical guide layer 1002, an active layer 1003, a cladding layer 1004, and a contact layer 1005 can be formed by performing an epitaxial growth only once. However, as in the AlGaAs DFB laser shown in FIG. 9, it is required that the active layer 1003 be positioned sufficiently close to the diffraction grating 1006. Accordingly, the semiconductor laser of FIG. 10 also has the problems that the light emitting efficiency and the product reliability are reduced and freedom of design of the device structure is restricted.
An optical device and an electron device employing an ultra thin semiconductor film have recently been studied in order to utilize a variety of quantum effects for obtaining higher performance.
FIG. 11 is a schematic view of a quantum well laser as an example of such devices. In the quantum well laser, the movement of electrons and holes is confined within a quantum well layer 1102 in a thickness direction by a pair of confining layers 1101 and 1103. Therefore, the quantum well laser has advantages such as lowered threshold current density and improved temperature characteristics, as described in Electronics Letters, vol. 18, 1095 (1982).
In such a quantum well, however, the electrons and holes are quantized only in a thickness direction, but not in a direction on a plane parallel to a main surface of the quantum well layer. Therefore, the reduction of the threshold current density and the improvement of the temperature characteristics are not sufficient. In order to solve these problems, semiconductor lasers having curved active layers as shown in FIGS. 12 and 13 are proposed. The lasers of FIGS. 12 and 13 can attain quantum wire effects and quantum box effects, respectively (Japanese Laid-Open Patent Publication Nos. 61-212084 and 61-212085, Journal of Crystal Growth 104 (1990), pp. 766-772).
In each of the lasers of FIGS. 12 and 13, a single active layer or a multiple active layer structure is formed as a gain area. The active layer is sufficiently thin to generate quantum effects and includes a diffraction grating having a sufficiently short periodicity to generate additional quantum effects in a direction on a plane parallel to a main surface of the active layer. By this construction, quantum wire effects and quantum box effects are obtained, namely, the movement of the electrons and holes is confined in a direction of the periodicity of the corrugation as well as in the thickness direction. As a result, semiconductor devices with improved performance are produced.
However, in order to form an active layer having a diffraction grating which is appropriate to obtain quantum effects, it is necessary to position the active layer within a short distance from the corresponding corrugation formed on the substrate. This means that the freedom in designing the device structure is restricted. Moreover, it is difficult to avoid the problems arising from the non-radiative recombination center generated at the interface along the corrugation formed on the substrate.

Semiconductor device and a method for producing the same


The present invention provides a compact and high-performance image pickup lens having a fast F-number and capable of suppressing shading by using a curved projection surface. An image pickup lens 10 includes a first lens L1 having a positive refractive power, a second lens L2 having a negative refractive power, a third lens L3 having a positive or negative refractive power, a fourth lens L4 having a positive or negative refractive power, and a fifth lens L5 having a negative refractive power. With regard to the fifth lens L5 among these lenses, at least one surface is aspherical. The above-described image pickup lens 10 satisfies a conditional expression (1): −2.50<f5/f<−0.10 . . . (1) where f5 is a focal length of the fifth lens L5 and f is a focal length of the entire system of the image pickup lens 10.

In recent years, a compact image pickup device using a solid-state image sensor, such as a CCD (Charge Coupled Device) type image sensor or a CMOS (Complementary Metal Oxide Semiconductor) type image sensor, has been mounted on a mobile terminal, such as a portable telephone or a PDA (Personal Digital Assistant), and furthermore also on a notebook computer and the like, allowing not only audio information but image information to be transmitted to and from a remote place.
In the solid-state image sensor used for such an image pickup device, in recent years, the miniaturization of a pixel size progresses, and the increase in the pixel density and the miniaturization of the image sensor have been achieved. Furthermore, it also becomes possible to curve an image pickup surface and thus there is a need for a compact and high-performance image pickup lens optimum for such an image sensor.
Patent Literature 1 discloses an image pickup device with a curved solid-state image sensor. In Patent Literature 1, by curving the solid-state image sensor into a polynomial surface shape, the field curvature and distortion aberration that are caused by lenses are corrected in a balanced manner and a compact and high-resolution image pickup device is provided. However, because the solid-state image sensor has a CIF (Common Intermediate Format) size (352 pixels×288 pixels) and the image pickup lens has only one lens, chromatic aberration is not fully corrected. Therefore, a high-performance image pickup device cannot be expected to be obtained using a higher pixel density solid-state image sensor.
Patent Literature 2 and Patent Literature 3 disclose image pickup lenses having a curved image pickup surface, a photographing angle of approximately 77°, and the speed or brightness of F 5.7 to F 6.2 for the applications of a compact camera and a film unit with a lens. Here, the image pickup lens is a post-positioned aperture triplet type lens comprising a positive first lens, a negative second lens, a positive third lens, and an aperture stop.
However, in the case of the image pickup lenses of Patent Literature 2 and the like, a sufficient performance cannot be obtained with an F-number slower or darker than F 5, and the back focus of the triplet type lens as described above tends to be long, and therefore the sizes of the image pickup lens and the image pickup device will increase.
Moreover, Patent Literatures 2 and 3 relate to image pickup lenses for film cameras and attempt to improve performances by curving a film surface (image pickup surface) in accordance with the field curvature that is caused by the lens. However, each of the image pickup lenses is an image pickup lens for cameras using a roll film and therefore because of the structure of the camera, the film surface results in the so-called cylindrical image pickup surface where the film surface curves only in a long side direction of a picture plane. For this reason, while a favorable performance can be obtained in the long side direction of the picture plane, the image pickup surface in the short side direction of the picture plane remains planar, and therefore not only an improvement in the performance cannot be achieved but also degradation may be caused in accordance with the correction state of the field curvature. With the curving only in the long side direction of an image pickup surface as with Patent Literatures 2 and 3, it is difficult to obtain high performance across the entire picture plane. Therefore, usually the focal depth is set deep by setting the F-number of the lens slow so that a blur in the plane direction is prevented from becoming conspicuous, and therefore it has been difficult to set the F-number faster or brighter.
Furthermore, because the image pickup lenses of Patent Literatures 2 and 3 are the ones for film cameras as described above, incidence angles of principal rays of light rays incident upon an image pickup surface is not necessarily designed so as to be sufficiently small on the periphery of the image pickup surface. In the image pickup lens for forming an object image onto a photoelectric conversion unit of a solid-state image sensor, when principal ray incidence angles of light rays incident upon the image pickup surface, i.e., the so-called telecentric characteristic, degrades, the light rays will enter obliquely to the solid-state image sensor, and a phenomenon (shading) occurs which decreases an effective aperture efficiency on the periphery of the image pickup surface, resulting in an insufficient quantity of light in the periphery.
Patent Literature 4 discloses an example of achieving higher performance by combining four lenses with a curved solid-state image sensor. However, because a lens nearest to the image side is a positive lens, a total length is long and the aberration correction is also insufficient as compared with the total length, and thus these examples cannot meet with the higher pixel density and larger aperture in recent years.
On the other hand, as a compact and high-performance lens, an image pickup lens comprising five lenses has been proposed because it can achieve higher performance as compared with an image pickup lens comprising three or four lenses.
Patent Literature 5 discloses the so-called telephoto type image pickup lens comprising, in order from an object side, a first lens having a positive refractive power, a second lens having a negative refractive power, a third lens having a positive refractive power, a fourth lens having a positive refractive power, and a fifth lens having a negative refractive power and attempting to reduce a total length of an image pickup lens (a distance on an optical axis from a lens surface on a side closest to an object of an entire system of an image pickup lens to an image side focal point).
However, with regard to the image pickup lens described in Patent Literature 5, principal ray incidence angles with respect to an image pickup surface is 26° or more at the maximum and the telecentric characteristic is not good, and furthermore a reduction of the total optical length is also insufficient and the F-number is also as slow as approximately F 3.0.

Image pickup lens and image pickup device


A hub-bearing assembly (10) for a motor vehicle wheel is provided with a flanged hub (12), a disc brake rotor (40) and a disc-shaped sealing shield (50) having a radially inner mounting portion (51, 51′) mounted with radial interference on a cylindrical surface (30) of the stationary bearing ring (14), a shaped wall (52, 52′) extending radially from an axially inner end (53) of the mounting portion (51), and an outer, peripheral sealing edge (54) defining a labyrinth seal with a surface (46) of the disc brake rotor.

U.S. 2011/0221142 A1 discloses a hub-bearing assembly of the type defined in the preamble of claim 1, which has an axis of rotation and comprises:                a flanged hub rotatable about the axis of rotation, the hub having a flange integral therewith and transverse to the axis of rotation, the flange having a plurality of angularly spaced axial bores for a corresponding plurality of bolts for fastening a disc brake rotor and a wheel to the flanged hub;        a stationary bearing ring arranged radially on the outside of the flanged hub, the ring forming a projecting tubular portion which extends in an axially outer direction and has a radially outer surface of axial cylindrical shape;        a disc brake rotor fixed to the flange of the hub, the rotor having a surface facing said cylindrical surface of the ring;        at least one sliding contact sealing device mounted between the tubular projecting portion, the outer ring and the flanged hub.

Hub-bearing assembly for a motor vehicle wheel


An endoscopic surgical scissors instrument is provided with end effectors having arcuate cammed surfaces proximal their pivot points. The instrument includes a pair of scissor blades coupled to a pivot post such that at least one blade is pivotally movable with respect to the other from an open position to a closed position. The blades have inside cutting edges which engage each other in bearing contact as the blades are moved from the open to the closed position. In addition, each blade is bowed so as to effect a biasing of the cutting edges together in positions near the closed position. The arcuate cammed surface on the blades are located behind the pivot post, and the cammed surfaces push the blades apart behind the pivot post, thereby urging the cutting edges in front of the pivot post together in the open position of the blades. The cammed surfaces are arranged so that they exert a progressive biasing of the cutting edges together with the most biasing when the blades are in the open position and the least biasing when the blades are in the closed position. By requiring the cams to be arcuate, the cams contact each other in many locations as they slide over each other, thereby reducing wear and increasing stability.

The invention relates to endoscopic instruments. More particularly, the invention relates to an endoscopic scissors instrument with a cammed biasing surface between scissor blades whereby the cutting edges of the scissor blades are variably biased together as the scissor blades pivot with respect to each other.
Various kinds of scissors are well known in the art. Scissors generally consist of a pair of scissor blades each having an internal cutting edge and a pivot means whereby at least one of the scissor blades pivotally engages the other scissor blade such that its inside cutting edge engages the inside cutting edge of the other scissor blade in bearing contact from a point near the pivot means to a point along the cutting edges distal from the pivot means. In order to effect a smooth cutting action, the engaging cutting edges must be kept in a single moving point of close contact throughout the pivoting of the blades. Continuous close contact of the cutting edges is usually accomplished two ways: first, by biasing the blades together at the pivot means; and second, by constructing the blades with a bowed profile. Prior art FIGS. 1a-1e show an example of this construction.
FIGS. 1a and 1b show a prior art scissors 101 having a first scissor blade 102 and a second scissor blade 104. Each blade has an inside cutting edge 106, 108 and the blades are pivotally joined at a pivot means 110. The blades pivot one with respect to the other, or both with respect to each other, about pivot means 110 from an open position shown in FIG. 1a to a closed position shown in FIG. 1b. Cutting is effected at the bearing contact of one cutting edge with respect to the other as shown by the circled area 112 in FIG. 1a. As will be appreciated, this bearing contact 112 moves from a point near the pivot means 110 as shown in FIG. 1a along the length of cutting edges 106, 108 to a point 114 shown in FIG. 1b as the blades pivot from the open position shown in FIG. 1a to the closed position shown in FIG. 1b.
In order that the cutting action of the scissors be smooth and consistent throughout the movement of the bearing contact from one position to another the cutting edges 106, 108 must be biased together in a direction parallel to the axis of the pivot means 110. Biasing the cutting edges together when the bearing contact 112 is near the pivot means 10 is usually accomplished by providing the pivot means with a biasing member. For example, pivot means 110 is often threaded with a tightening nut or the like which supplies a biasing force which presses the blades together. In actual practice, most hand operated scissors are relatively loose in the open position and the user manually biases the bearing contact by manipulation of the handles. The biasing force applied at the point of pivot means 110 has little effect, however, in biasing the cutting edges together at the point of bearing contact 114 (FIG. 1b) when the blades are pivoted to the closed position.
In order to effect a sufficient biasing of the blades together at bearing contact 114 and throughout the bearing contacts from 112 to 114, the blades are constructed with a slightly bowed profile. FIG. 1c shows a top view of blades 102 and 104 illustrating their respective bowing towards each other. While it will be generally appreciated how this bowing of the blades serves to bias their cutting edges together as the blades pivot towards the closed position, FIGS. 1d and 1e further illustrate this by showing a top view of the blades when the bearing contact 112 is close to the pivot means (FIG. 1d) and a top view of the blades when the bearing contact 114 is furthest from the pivot means (FIG. 1e).
This conventional construction of a scissors is normally quite acceptable. Generally, the bowing of the blades provides reliable biasing of the cutting edges at bearing contact points distant from the pivot means because the blades are tempered and their bowed profile remains relatively constant throughout the life of the scissors. The primary problem with conventional scissors relates to the biasing of the cutting edges together when the blades are in the open position. The open position biasing relies on the biasing means which is subject to wear and eventual loosening resulting in a failure to bias the cutting edges together when the bearing contact of the cutting edges is at position 112 near the pivot means 110. In addition, the biasing provided by the bowing of the blades when the scissors is in the closed position further operates to loosen the biasing at the pivot means since the biasing at the pivot means continues constantly throughout the movement of the blades from the open to the closed positions. Eventually, the user is forced to compensate greatly for this failure of the scissors, and at some point the scissors is deemed inoperable. An additional problem with conventional scissors is that they often do not provide an even feel over the entire cutting range.
These disadvantages are most problematic in small scissors, and in precision cutting scissors such as surgical scissors. In these types of scissors it is important that the blades move smoothly and evenly throughout the entire cutting range. In addition, the problems of the prior art scissors are magnified in small endoscopic scissor instruments. In a standard type scissors, the operator's hands can reflexively adjust biasing of the blades in the open position by manipulation of the handle to effect a smooth cutting action, and the operator's hands receive feedback as the scissors pivot through their entire cutting range. In an endoscopic instrument, however, the handles of the instrument are not directly connected to the blades. Rather the handles are used to move an actuator means which pivots the blades. Thus, manipulation of the handles to effect biasing in the open position will be completely ineffective.
Various improvements in standard type scissors have been proposed over the years. Several of these proposed improvements involve the use of cammed surfaces. U.S. Pat. No. 1,956,588 to Parker et al. discloses a scissors having two pairs of cammed surfaces in the vicinity of the pivot screw. The scissors disclosed by Parker et al. are "detachable blade scissors" where the blade edges are fine and wire-like and are detachable from the blades. When moving such scissor blades from the wide open position towards a closed position, there is a possibility that the detachable blade edges will cross each other preventing closing of the scissors which is quite the opposite from the problem described above where the cutting edges need to be brought closer together when in the open position. In order to prevent the removable blade edges from crossing, cams are provided on the inner surfaces of the blades so that as the blades are moved from the wide open position towards the closed position, the cams ride up on each other and force the blades apart on the cutting side of the pivot screw in the vicinity where the cutting edges are about to meet. Moreover, since these scissor blades are not bowed, biasing of the cutting edges together throughout the shearing stroke is encouraged by another pair of cammed surfaces on the inside surface of the blades which bias the blades apart behind the pivot screw as the blades are closed.
U.S. Pat. No. 2,627,656 to Richartz also discloses a scissors formed without a bowed profile where each blade is provided with a cam-like bearing face on the inside face of the blade behind the pivot axis. The cams are shaped so that their height increases from their ends to their center so that the high points of the cams are in contact when the blades are in the closed position. These cams take the place of the bowing of the blades and force the blades together as they are closed. Richartz does not provide any means for biasing the cutting edges together when the blades are in the open position. U.S. Pat. No. 4,420,884 to Hembling similarly discloses a non-bowed scissors which are constructed of sheet metal stock and coined in a die assembly to form a control cam which biases the cutting edges of the blades together in place of bowing. Also, U.S. Pat. No. 3,688,402 to Shannon discloses a disposable surgical scissors which have camming surfaces in the vicinity of the pivot screw which bias the cutting edges together as they are moved from the open to the closed position in a manner similar to the scissors disclosed by Richartz and Hembling.
U.S. Pat. No. 4,133,107 to Vogel discloses a scissors with a bearing dimple on the inside face of one blade behind the pivot screw and a mating hole on the other blade. This dimple constantly biases the cutting edges together while the blades are moved from the open position to the closed position and vice versa, but does not bias the cutting edges in the wide open position or in the fully closed position.
U.S. Pat. No. 3,376,641 to Usborne discloses scissors and shears where the inner face of each blade has a shoulder. The shoulders protrude from each face at the same distance as each other from the handle side of the pivot, with the face of each shoulder obliquely transverse of the blade and rising in the direction away from the cutting edge. The transverse obliquity of the shoulders ensures that the inside faces of the blades are mutually oblique behind any point of contact of the cutting edges, thus providing clearance or relief of one blade from the other behind its cutting edge. Usborne teaches controlling the blade positions at all stages between fully open and fully closed by providing the shank of each blade, over a length embracing the shoulder, with a back edge shaped such that progressive contact is made between the two shaped edges, and each such contact is always in a substantially straight line that intersects the pivot axis and the corresponding point of contact between the cutting edges of the blades. Accordingly, as the blades of Usborne's scissors are moved from the open to the closed position, the point of contact between the back edges moves away from the pivot point. While Usborne's scissors seem to provide biasing of the cutting edges together near the pivot point when the blades are open, the geometry of Usborne's shoulders and back edges is complex. Usborne's scissors require that there be a substantial shank on each blade, that is, that there be a significant length of blade behind the pivot point leading to the handle. Moreover, as Usborne's biasing resides specifically on a single moving point or a single line of points, the blades are subject to undue wear on that line of points. Thus, Usborne's scissors are not particularly adaptable for use with endoscopic surgical scissors. The geometry is too complex for such small scissors, and the biasing means requires a substantial shank or tang on each blade behind the pivot point and there is no room for such on the end effector of an endoscopic tool. Even if the geometry could be arranged on such small scissors, with a moving point of contact, the tiny shanks would quickly wear and become unreliable.

Endoscopic scissors instrument with cammed surface end effectors


This invention is directed as “a device of hard disk shock-resistance”, mainly consists of an outer frame, an inner frame, and multiple absorbers. With multiple assembly and tool holes arranged in appropriate position, the absorbers are snapped in-between the assembly holes of the outer and inner frames to create a buffer area which protects hard disk from breaking down in severe shocking environments, while it is still convenient to mount and dismount the hard disk with easy unit assembly.

I. Field of the Invention
The present invention provides a mechanism relating to "a device of hard disk shock-resistance", especially refers to a damping-buffer structure, which can absorb shocks from any directions toward the hard disk; its absorbers once installed are uneasy to loosen off, and the mounting and dismounting the disk on/from the present invention is convenient.
II. Description of the Prior Art
Owing to being one of the standard popular equipment of conventional notebook PC or other portable electronic appliance equipped with hard disk, the demand quantity of hard disk becomes very huge and makes the disk volume grow larger and production cost lower. This fact does not change one of the defective points of hard disk, that is, the reader tends to scratch the surface of disk platter by unexpected violent vibrating.
Thereafter, hard disk manufacturer worked in an effort to enhance the shock-resistance ability. Although the shock-resistance ability did improve steadily, the improved hard disk still could not meet the requirement of avoiding the unexpected violent vibrating in a moving vehicle. How to overcome the potential damage caused by the shock of car wheel rolling over the uneven pavement is an urgent measure. In order to meet the above-mentioned requirement, the present invention designed a shock-resistance device consisting of two frames connected with multiple absorbers to protect hard disk from damaging by effectively damping out the shocks from any directions, despite the convenience of assembling or disassembling the frames, the absorbers, and the hard disk into one unit or several parts.


A method for accelerating data operations across a plurality of nodes of one or more clusters of a distributed computing environment. Rack awareness information characterizing the plurality of nodes is retrieved and a non-volatile memory (NVM) capability of each node is determined. A write operation is received at a management node of the plurality of nodes and one or more of the rack awareness information and the NVM capability of the plurality of nodes are analyzed to select one or more nodes to receive at least a portion of the write operation, wherein at least one of the selected nodes has an NVM capability. A multicast group for the write operation is then generated wherein the selected nodes are subscribers of the multicast group, and the multicast group is used to perform hardware accelerated read or write operations at one or more of the selected nodes.

Distributed computing systems and environments have quickly gained popularity in both commercial and individual applications, due at least in part to their ability to efficiently scale and handle the massive data streams that are often associated with big data computing problems. As analytical techniques have become increasingly advanced and the pricing for commodity hardware has become more accessible, big data computing applications have flourished and a number of platforms and frameworks have been developed in order to support such big data computing endeavors.
Apache Hadoop is an open-source framework that is commonly utilized to handle distributed storage needs in big data computing. Under the Hadoop framework, commodity hardware is organized into compute clusters, each containing a plurality of nodes, which are designed to be highly fault tolerant. Storage in Hadoop is governed by the Hadoop Distributed File System (HDFS), which operates by splitting a received file into blocks and distributing these blocks across various nodes in a cluster. This distribution pattern enables local parallel processing of the dataset, which is generally more efficient than attempting to process the dataset using a conventional architecture. However, HDFS replication processes are often taken over a random selection of nodes and are driven by software, leading to throughput and latency issues. Accordingly, improvements are needed.
Apache Kafka is an open-source stream processing platform that is commonly utilized to handle processing of real-time data feeds or other streaming data sets. A Kafka cluster is organized to receive messages from one or more producers and to distribute messages to one or more consumers. Kafka organizes messages received from producers into one or more topics, with each topic being partitioned into one or more partitions. These partitions can then be distributed across the physical nodes of the Kafka cluster, similar to the manner in which HDFS distributes blocks across the physical nodes of an HDFS cluster. However, Kafka itself provides functionality akin to a memory buffer, and does not guarantee that a message transmitted to a physical node of the Kafka cluster has in fact been persisted to disk. Furthermore, when performing cluster mirroring operations, Kafka can experience latency and buffer issues due to the tight coupling required between source and destination Kafka clusters or between producers and consumers. Accordingly, improvements are needed.

Accelerating data replication using multicast and non-volatile memory enabled nodes


A golf practicing apparatus is provided which includes a club with a latch member. A target is provided which is held by a mount. When the golf club is swung in a predetermined manner, the target is released from the mount and is connected with the golf club. When the golf club is swung in an improper manner the target pivots downward and is retained by the mount.

To develop a consistent golf swing many fundamentals must be learned some of which include the following. The golf club must be swung along a correct swing plane that is an imaginary circular path that is parallel to the target line. The target line is a line from the golf ball to the flag or desired target point. The golf club must strike the ball with the leading edge of the clubface perpendicular to, or at a ninety-degree angle to the target line. Accordingly, it is desirable to provide an apparatus that reinforces the aforementioned fundamentals by which a golfer can use to practice developing a consistent golf swing. Additionally, during inclement weather or seasonal weather conditions, it is desirable to provide an apparatus with which one can practice golf swing fundamentals year round in an indoor setting.

Practice golf club, target, and swing platform apparatus


A method for preparing a ratiometric fluorescent sensor for paracetamol based on a copper nanoclusters-carbon dots-arginine composite is provided. Copper nanoclusters CuNCs with red fluorescence are bonded to carbon dots (CDs) with blue fluorescence by electrostatic adsorption and hydrogen bonding, and then arginine is added to form the CuNCs-CDs-arginine composite. The addition of arginine leads to a significant decrease in the blue fluorescence of the CDs, while after the paracetamol is added, the blue fluorescence of the CDs gradually recovered as a result of the specific binding of arginine to paracetamol. The ratiometric fluorescent sensor for paracetamol is constructed by taking the fluorescence of the CuNCs as a reference signal, and the fluorescence of the CDs as a response signal, and fitting the linear relationship between the ratios ICDs/ICuNCs of fluorescence emission peak intensities of CDs and CuNCs and the molar concentrations of paracetamol.

Paracetamol, also known as acetaminophen, is a commonly used over-the-counter phenolic analgesic with anti-inflammatory and antipyretic effects. A small dose of paracetamol is beneficial to the human body, but overdose may cause health issues such as kidney failure, liver necrosis and the like. In fact, paracetamol overdose is one of the main causes of liver failure. Developing a simple, accurate and quantitative detection method for paracetamol in human serum is important for monitoring human health.
At present, there is increasing research on analytical techniques for the detection of paracetamol, including electrochemistry, colorimetry, chemiluminescence, fluorescence and other methods. Song et al. constructed a graphite oxide modified glass carbon electrode for electrochemical behavior determination of paracetamol (Jinchun Song, Ji Yang, Junfen Zeng, Juan Tan, Li Zhang. Graphite oxide film-modified electrode as an electrochemical sensor for acetaminophen. Sensors and Actuators B-Chemical, 2011, 155, 220-225). Alam et al. used β-Cyclodextrin where subject interacts with object and multi-walled carbon nanotubes with oxidation reduction property for the sensitive detection of trace paracetamol (Arif Ul Alam, Yiheng Qin, Massimo Catalano, Luhua Wang, Moon J. Kim, Matiar M. R. Howlader, Nan-Xing Hu, M. Jamal Deen. Tailoring MWCNTs and β-Cyclodextrin for Sensitive Detection of Acetaminophen and Estrogen. ACS Applied Materials & Interfaces, 2018, 10, 21411-21427).
Junhua Li et al. constructed an electrochemical sensor for paracetamol based on nanocomposite modified electrode (Junhua Li, Mengqin Liu, Fuxing Zhang, Zhifeng Xu, Peihong Deng, Siping Tang, Xing Liu. CoFe2O4NWs-RGO nanocomposite and paracetamol electrochemical sensor prepared based on CoFe2O4NWs-RGO nanocomposite. Chinese Invention Patent Publication No. CN106248766A). Xuecai Tan et al. reported a molecularly imprinted electrochemical analysis method for the determination of paracetamol (Xuecai Tan, Yuexin Sun, Huicheng Yu, Zaiyin Huang, Shaogang Liu, Fuhou Lei. Molecularly imprinted electrochemical sensor for paracetamol and preparation method thereof. Chinese Invention Patent Publication No. CN102735729A). Yaping Ding et al. constructed a fluorescent probe based on amino acid-modified CdTe nanoparticle for quantitative detection of paracetamol (Yaping Ding, Yaxiang Lu, Li Li, Liqiang Luo, Yu Cheng, Method for determining paracetamol by CdTe nano fluorescent probe. Chinese Invention Patent. Publication No. CN102519921A).
Methods of analysis and detection of paracetamol mainly include electrochemical analysis and fluorescence analysis. These methods only rely on a single signal output, which is susceptible to factors such as background, reagents, system and environmental conditions, resulting in fluctuations in measurement results. In contrast, employing the dual-signal ratio processing to obtain the intensity ratio of the signals achieves a self-calibration function, which effectively eliminates the interference of the autologous signal and the background signal and improves the accuracy and reliability of the detection results. In this regard, the present disclosure reports a ratiometric fluorescent sensor for paracetamol based on a copper nanoclusters-carbon dots-arginine composite. Copper nanoclusters CuNCs with red fluorescence are prepared by using DNA as a template, and bonded with carbon dots (CDs) with blue fluorescence by electrostatic adsorption and hydrogen bonding, and then arginine is added to form the CuNCs-CDs-arginine composite. The addition of arginine leads to a significant decrease in the blue fluorescence of the CDs. After the paracetamol is added, the blue fluorescence of the CDs gradually recovered as a result of the specific binding of arginine to paracetamol which causes separation of the arginine from the CDs. The addition of the arginine and the paracetamol do not significantly cause change in the fluorescence of the CuNCs. The ratiometric fluorescent sensor for paracetamol is constructed by taking the fluorescence of the CuNCs as a reference signal, and the fluorescence of the CDs as a response signal and fitting the linear relationship between the ratios ICDs/ICuNCs of fluorescence emission peak intensities of the CDs and the CuNCs and the molar concentrations of paracetamol. Constructing the ratiometric fluorescent sensor based on a CuNCs-CDs-arginine composite and the ratiometric fluorescent method for detecting paracetamol has not been reported in domestic and foreign literatures and patents.

Method for preparing a ratiometric fluorescent sensor for paracetamol based on a copper nanoclusters-carbon dots-arginine composite


An impact well configured to reduce the turbulence in a flowing fluid. The impact well has the shape of a frustum and includes an upper portion, an intermediate portion and a base portion. The base portion includes a domed portion that extends upwards into the intermediate portion. The upper portion, the intermediate portion and the base portion each included stepped areas configured to assist in the alignment of the portions and the assembly of the well.

Generally, during a casting process molten metal is poured into a casting mold and allowed to cool in order to form a cast part. As the molten metal is poured into the casting, the molten metal typically exhibits highly turbulent flow. The turbulent flow of the metal may cause the metal to trap air and impurities which develop inclusions as the metal cools, thereby requiring additional steps to ensure the cast component meets desired quality standards. Accordingly, reducing the degree of turbulent flow of the molten metal as the metal is poured into the casting mold increases the quality of the resulting cast component.

Turbulence inhibiting impact well for submerged shroud or sprue poured castings


In an optical receiver which is compatible with a plurality of signal channels, it is difficult to receive signals properly because a variation in receiving light sensitivity of a photoelectric conversion unit occurs between a plurality of signal channels, therefore, an optical receiver according to an exemplary aspect of the invention includes an optical processing circuit processing input signal light to have been input and outputting a plurality of output signal light beams; and a plurality of photoelectric conversion means for receiving the plurality of output signal light beams respectively and outputting electric signals, wherein the photoelectric conversion means includes an avalanche photodiode which can control a multiplication factor of an output current as the electric signal by means of an applied voltage; and the avalanche photodiode operates with a driving voltage by which the output currents in the plurality of photoelectric conversion means become almost the same.

The backbone transmission system is required to further increase its capacity with the amount of information (traffic) in the Internet increasing. The technology for increasing the capacity includes an optical transmission technology using a plurality of channels such as an optical multilevel modulation system and a polarization multiplexing system. It has become more important to improve receiving sensitivity with the capacity increasing, and a coherent optical transmission technology in which the receiving sensitivity is very high has received a lot of attention. In the coherent optical transmission technology, AC (Alternating Current) signal components are received which have been amplified by mixing signal light and local oscillator (LO) light in a coherent optical receiver. At that time, the larger amplifying action works on the signal light as the optical output of the local oscillation (LO) light becomes larger, and therefore receiving characteristics with a high S/N (Signal/Noise) ratio can be obtained by inputting the larger local oscillation (LO) light compared to the signal light.
Patent literature 1 describes an example of such a coherent optical receiver compatible with a plurality of channels. A coherent optical receiver described in patent literature 1 includes an optical signal processing unit performing signal processing on input optical signals, separating the signals and outputting separated signals from a plurality of output ports; and a photoelectric conversion unit performing photoelectric conversion on the optical signal output from each output port and outputting the result. It further includes a plurality of output terminals having a space wider than a space between output sections of the photoelectric conversion unit; and an electric wiring unit connecting a plurality of electric signals output from the photoelectric conversion unit to a plurality of output terminals. Here, the photoelectric conversion unit is separated into a plurality of units and disposed on the center line of an output terminal of a connection destination. The optical signal processing unit has an optical expansion section where optical wiring is laid so as to be photo-coupled to photoelectric conversion units where the outputs from the plurality of output ports are separated into a plurality of ports and arranged.
The configuration enables the photoelectric conversion unit disposed separately to be disposed so that the distance to the output terminal may become shorter. They say, therefore, that it becomes possible to suppress the deterioration of output electric signal levels of the related coherent optical receiver having multi-channel outputs.

Optical receiver and method for controlling optical receiver, optical receiver, method for controlling optical receiver, and method for receiving light


A method for monitoring the temperature of a product wafer during thermal processing of the product wafer in an emissivity independent thermal processing system includes processing a test wafer in the emissivity independent thermal processing system that thermally processes the product wafer. The test wafer is pretreated before being thus placed in the thermal processing system. The test wafer is thermally processed following a substantially same thermal processing recipe as that used for thermal processing of the product wafers. After the thermal processing of the test wafer, a sheet resistance of the test wafer is measured. This sheet resistance is correlated to a wafer temperature at the test wafer that was achieved during the thermal processing of the test wafer. Because the product wafer and the test wafer are thermally processed within an emissivity independent thermal processing system, the test wafer temperature is correlated to a product wafer temperature at the product wafer that was achieved during the thermal processing of the product wafer. With such monitoring of the product wafer temperature during actual thermal processing of the product wafer, thermal processing may be more tightly controlled to ensure that a thermal processing recipe is accurately followed.

A thermal processing system which heats up a wafer is a common part of the integrated circuit fabrication process. The wafer may require heating to high temperatures such as 200.degree. Celsius to 1500.degree. Celsius for common processing steps such as annealing or reflow. RTP (Rapid Thermal Processing) systems heat up the wafer to a relatively high temperature within a relatively short period of time, and are prevalently used in integrated circuit fabrication systems.
A thermal processing recipe typically includes a step of heating a product wafer to a specified temperature for a specified time period in accordance with a specified temperature versus time characteristic to achieve a specified result. In order to follow the recipe with precision, the wafer temperature achieved for various temperature settings within a thermal processing system may be monitored.
A common way of monitoring the wafer temperature achieved within the thermal processing system heats up a test wafer and then measures the sheet resistance of the test wafer after the test wafer cools down. This measured sheet resistance is correlated to the test wafer temperature that was achieved during heating of the test wafer. The test wafer is pretreated with a specified process that is known to provide an accurate correlation of sheet resistance (measured after the test wafer has been heated up within the thermal processing system) to the temperature that was achieved at the test wafer during heating of the test wafer within the thermal processing system.
Some prior art thermal processing systems are not emissivity independent meaning that a same wafer temperature is not achieved for two wafers having different prior process histories when those two wafers are thermally processed following a substantially same thermal processing recipe. Thus, in prior art thermal processing systems which are not emissivity independent, a test wafer, which typically has a pretreatment different from the product wafer, cannot accurately reflect the temperature reached at the product wafer.
Accordingly, in the prior art nonemissivity-independent thermal processing system, such a test wafer is used in isolation to monitor the calibration of temperatures achieved within the thermal processing system for various temperature settings. The temperature achieved on a product wafer during actual processing of the product wafer is not determined. However, determination of the temperature achieved on the actual product wafer during thermal processing would allow more accurate control during thermal processing of the product wafer.
More recently, thermal processing system manufacturers are providing thermal processing systems which are emissivity independent such as that available from Applied Materials, Inc, Santa Clara, Calif. Two wafers having different prior process histories achieve substantially same temperatures with substantially same thermal processing recipes within an emissivity independent thermal processing system.
With such an emissivity independent thermal processing system, the temperature achieved at an actual product wafer during processing of the product wafer may be determined from measuring the sheet resistance of a test wafer. Such a determination would allow more accurate control of thermal processing of product wafers.

Monitoring wafer temperature during thermal processing of wafers by measuring sheet resistance of a test wafer


A semiconductor assembly includes two leads, a primary die and a secondary support structure. Impedance networks of the secondary support structure establish an impedance between each lead and a different bond pad of the primary die. Although the distances between each bond pad and lead are substantially different, the impedances between each bond pad and lead are substantially the same.

The invention relates to controlling impedances of an integrated circuit.
Referring to FIG. 1, an integrated circuit chip, or package 10, typically includes a semiconductor die 17; pins, or leads 12; and a packaging material 3 that encapsulates the die 17 and holds the leads 12 in place. The core circuitry of the package 10 is fabricated in the semiconductor die 17, and the leads 12 form terminals for electrically connecting the circuitry on the die 17 with external circuitry.
Referring to FIG. 2, one way to make the package 10 includes mounting the die 17 on a center piece, or paddle 18, of an electrically conductive leadframe 11. Either a conductive or a nonconductive adhesive (e.g., an epoxy) may be used to secure the die 17 to the paddle 18. When a conductive adhesive is used, a dielectric layer may be placed between the die 17 and the paddle 18. During the initial stages of manufacture of the package 10, the leads 12 are an integral part of the leadframe 18 and extend inwardly toward the die 17.
To electrically connect the die 17 to the leads 12, bonding wires 14 are attached between the leads 12 and bond pads 15 of the die 17. One of the final steps of making the package 10 includes encapsulating the die 17 with the packaging material 3 which leaves a portion of the leads 12 exposed. After the encapsulation, the webbing of the leadframe 11 that connects the leads 12 together is cut away to electrically isolate the leads 12.
Referring to FIG. 3, another way to make an integrated circuit package 20 includes eliminating the bond wires 14 and alternatively mounting leads 22 of a different type of leadframe 26 directly to the die 17. Often called "tab bonding," the free ends of the leads 22 extend over the die 17 and mount directly to the bond pads 15 (shown in FIG. 3 by dotted lines). Besides establishing electrical connections with the die 17, the leads 22 also secure the die 17 to the leadframe 26. Regardless of whether the leads are directly mounted to the bond pads or mounted via bond wires, the extension of the leads over the die is often called a leads over chip (LOC) mounting scheme.
The different leads 12 are used for different purposes. For example, some of the leads 12 might be used to establish a ground connection, some might be used to carry supply voltages, and some might be used to connect circuitry on the die 17 to external components (e.g., a crystal or a large resistor) that are not fabricated on the die 17. Quite often, some of the leads 12, are used as I/O pins to transmit and receive data, control and address signals.
These I/O pins might be used to transmit and receive high frequency signals, such as, for example, signals that represent bits of data for a high speed memory device. At these high frequencies, even slight differences in the length of the bond wires 14 may cause the impedances present at the I/O pins to vary among the pins.
As an example of different bond wire lengths, a lead 12b (see FIG. 4) might be connected to a bond pad 15b (via a bond wire 14b) that is located near an edge (of the die 17) that is close to the lead 12b. However, a lead 12a that is adjacent to the lead 12b might be connected to a bond pad 15a (via a bond wire 14a) that is located near an opposite edge of the die 17. As a result, the impedances present at the two leads 12a and 12b are substantially different which can affect the performance of the package 10.

Controlling impedances of an integrated circuit


A welding power supply unit includes an outer enclosure having a plurality of sides that encompass internal components of the welding power supply unit. The welding power supply unit also includes a roll cage assembly having a plurality of roll bars. Each roll bar is disposed generally parallel with, but not adjacent to, an edge of a side of the outer enclosure and external to the outer enclosure. At least two of the roll bars are associated with handle portions that rotate with respect to the respective roll bar. Each handle portion includes an extruded tubular aluminum bracket or a die cast aluminum bracket disposed around its respective roll bar. In addition, the welding power supply unit includes a plurality of fastening mechanisms attached to the outer enclosure, the fastening mechanisms securing the roll cage assembly to the outer enclosure.

The present invention relates generally to the field of welding systems, and more particularly to a welding power supply unit that includes a roll cage assembly with incorporated lift handles.
Welding systems and power supplies are frequently used in harsh environments where they may be exposed to debris, dust, and other deposits that can harm or damage the welding power supplies. Similarly, common welding environments may include exposure to vibrating and mechanical tools, contact with which could damage a welding power supply. In addition, welding systems and power supplies are often subject to excessive handling and transportation requirements. Furthermore, welding power supplies, which may weigh over 80 pounds, are frequently difficult and cumbersome to transport or reposition.

Welding power supply roll cage with incorporated lift handles


A device for supporting at least one optical component is disclosed and includes an optical component mount configured to engage and retain at least one optical component therein, a support member attached to the optical component mount, a support body having at least one longitudinal passage sized to receive the support member therein, the longitudinal passage in communication with at least one opening formed on the support body, a radial compression member in communication with the longitudinal passage and configured to radially compress the support member thereby coupling the support member to the support body, and at least one securing device attachable to the support body and configured to radially compress the radial compression member.

In the field of experimental optics adjustable mounts, supports, and post systems are commonly used to support and couple optical components to a work surface or optical table. Often, the performance of the optical system depends on the precision with which the optical elements and components are positioned. For example, imprecise positioning of a spatial filter within an optical system may result in a substantial degradation of system performance. Even a minute amount of movement of a single optical element can have a substantial effect on the optical system being implemented.
Generally, optical post systems enable a user to adjustably secure one or more optical mounts to a work surface or mounting substrate. Typically, these optical post systems are manufactured in a time-consuming, labor intensive machining process from aluminum and/or stainless steel. FIGS. 1 and 2 show an exemplary embodiment of an optical post. As shown, typically the optical post 1 includes base 3 configured to be detachably secured to the mounting substrate. Further, the base 3 includes a central passage 9 sized to receive a post 5 therein. A lock member 7 is positioned within a lock member recess 11 formed in the base 3. The lock member 7 is configured to engage and apply an axial clamping force f to the post 5 positioned within the passage 9, thereby coupling the post 5 to the base 3. While these optical post devices have proven successful in the past, a number of shortcomings have been identified. For example, the application of the axial clamping force f introduces an undesirable lateral displacement of the post 5 within the passage of the base 3. As a result, an optical component supported thereby may not be positioned at the desired location.
In light of the foregoing, there is an ongoing need for an optical support device capable of precisely positioning one or more optical mounts within an optical system.

Adjustable support device for optical components and methods of use


A glass-ceramic material that is doped with rare-earths and is especially suitable for lasers and optical amplifiers is disclosed. The glass-ceramic material is optically non-scattering, and the doping with rare earths is essentially in the microcrystalline phase. The glass-ceramic material is preferably made up from complexes of metals having a valency of three or greater and of halides of rare earth ions having a valency of three or greater. The rare-earth ions include an optically active rare-earth ion.

1. Field of the Invention
The present invention relates to new glass-ceramic materials especially for lasers or optical amplifiers, which macroscopically exhibit the advantage of glasses, namely: ease of preparation and of shaping and relatively low cost, and which microscopically exhibit the advantage of crystals, namely: high effective sections and good quantum efficiencies.
The present invention also relates to a process for the manufacture of such glass-ceramic materials.
2. Description of the Prior Art
There are already known glass-ceramic materials based on beryllium fluorides doped with rare earths, employed for their display property, as described by Auzel in Patent FR-2 077 731. On a microscopic scale these materials behave like microcrystals. However, these materials are toxic and scatter light. This scattering, which is useful in display, makes these materials unsuitable for being used in optical amplification.
Other glass-ceramic materials for laser application have been described by Rapp and Chrysochoos in J. Mat. Sci. 7 1090 (1972). They are oxide-based materials which exhibit the disadvantage that the rare-earth doping is not essentially in the crystalline phase. Overall, these glass-ceramic materials have laser properties which are inferior to those of the initial glasses (before heat treatment).
In the case of oxide-based glass-ceramic materials similar results have also been reported by Muller and Neuroth in J. Appl. Phys. 44 2315 (1973); there again the laser properties were inferior to those of the initial glasses (before heat treatment) because the rare earths were not mainly in the crystalline phase.
Mixed glass-ceramic materials based on oxide and fluorides have been described by Auzel, Morin and Pecile in Patent FR-7327 486 of 26.7.73 for use in display; they exhibit the advantage that the rare earths are only in the fluorine-containing microcrystalline phases, and this gives them a good emission efficiency. However, these materials are unsuitable for laser use because the size of the microcrystals of the order of a few micrometers makes them optically scattering.
Furthermore, glass-ceramic materials based solely on fluorides but not doped with optically active rare earths have been described, where their mechanical-properties are concerned, by Poulain and Grosdemouge in the journal Verres et Refractaires, 26 852 (1982). However, the microcrystalline phases of these glass-ceramics are of the Na.sub.7 Zr.sub.6 F.sub.31 type, that is to say are not constituted starting with the rare earth (LaF.sub.3).

Glass-ceramic materials especially for lasers and optical amplifiers, doped with rare earths


The method for product selection comprises the steps of selecting a product among a plurality of options of different products, said selection being carried out by remotely signaling a label that represents the selected product; checking that no other selection has been detected; checking that the detected selection lasts longer than a predetermined period of time or more than a predetermined electromagnetic field strength; and dispensing the selected product if it has been verified that no other selection has been detected and if it has been verified that the selection lasts longer than said predetermined period of time and less than the predetermined electromagnetic field strength, or canceling the selection of the product if another selection has been detected or the detected selection lasts less than said predetermined period of time or is greater than the predetermined electromagnetic field strength.

Dispensing or vending machines dispense items or products such as beverage cans, groceries, coffee, etc., so that they can function alone and without the need for an employee.
The user of these dispensing machines must select the desired product through a keyboard, either by means of a physical keyboard, for example, with numbers and/or letters, or by means of a keyboard on a touch screen.
This keyboard is used during the day by a large number of people, and it becomes dirty due to this use, which can imply a risk for the transmission of diseases due to viruses or bacteria that one of the users may leave behind. Furthermore, these keyboards are routinely subject to wear and tear.
From document WO2004025835 A1 a keyboard for product vending machines is known that comprises selection panels that do not contain mechanical elements that are subject to wear or tear, but their activation is as similar as possible to traditional keyboards based on physical buttons.
These types of keyboards are commonly referred to as touch keyboards and their operation consists of physically touching the outside of the desired selection.
Non-contact selection systems are also known, which are developed, for example, for multimedia game systems. Normally this type of selection systems are based on the recognition of movements that guide the selection of the desired option through several phases, such as, for example, movements from left to right to navigate between the available options and later another movement to validate the selected option.
However, these non-contact selection systems known in other fields of the art are not commonly used in dispensing machines.

Method and keyboard for product selection