An electrophotographic photoreceptor including a conductive substrate, and a photosensitive layer, an intermediate layer, and a surface layer formed thereon in this order, wherein the surface layer contains a Group 13 element and at least one of nitrogen or oxygen.

1. Technical Field
The invention relates to an electrophotographic photoreceptor for use in devices forming an image by an electrophotographic method, such as copying machine, and a process cartridge and an image-forming apparatus using the electrophotographic photoreceptor.
2. Related Art
Recently, the electrophotographic method has been used widely, for example, in copying machines, printers, and the like. An electrophotographic photoreceptor for use in image-forming apparatuses utilizing the electrophotographic method (hereinafter, sometimes referred to as a "photoreceptor") comes into contact with various materials and is exposed to various stresses in the apparatus and thus deteriorates gradually. However, on the other hand, it should also cope with the demand for digitalization and colorization of image-forming apparatuses and high reliability.
For example, the process of charging the photoreceptor involves the following problems. First, in the non-contact charging mode, discharge products deposit on the photoreceptor, causing problems such as image blurring. For this reason, for example, a system in which particles functioning as a polishing agent are added to the developer and the developer is removed in a cleaning unit is used in some cases for removal of the discharge products deposited on the photoreceptor. In such a case, the surface of the photoreceptor deteriorates gradually due to abrasion. On the other hand, systems utilizing the contact charging mode have been used widely recently. In this mode as well, the abrasion of the photoreceptor may be accelerated.
Under the circumstances above, there exists a need for prolongation of the life of the electrophotographic photoreceptor. Prolongation of the life of electrophotographic photoreceptor requires improvement in abrasion resistance and thus an increase in the hardness of the photoreceptor surface.
However, in a photoreceptor made of amorphous silicon having a surface of high-hardness, discharge products and the like deposit thereon often causing image blurring and image deformation, and this phenomenon is more distinctive, especially under high-humidity conditions. The same is true for the surface layer of an organic photoreceptor having an organic photosensitive layer.
For prevention of the problems mentioned above, carbon-based materials are often used as the surface layer of the photoreceptor.
However, improvement in film hardness of a carbon-based film, such as a hydrogenated amorphous carbon film (a-C:H) or a fluorinated film thereof (a-C:H,F), leads to color development of the film. Thus, abrasion of the surface layer of the carbon-based film leads to an increase in light transmission efficiency of the surface layer over time, causing a problem of an increase in sensitivity of the photosensitive layer below the surface layer. In addition, uneven abrasion of the surface layer in the surface direction also leads to uneven distribution of the sensitivity of the photosensitive-layer, causing a problem of image irregularity, especially when a halftone image is formed.
On the other hand, improvement in hardness and improvement in transparency are known to have a trade off relationship, as a general characteristic of carbon-based thin film materials. This is because, as for the carbon bond in the film, it is necessary to increase the rate of diamond-type sp3 bonding for improvement in hardness, while these films inevitably have graphite-type sp2 bonding causing light absorption, and reduction in the rate of the graphite-type sp2 bonding in the film by hydrogenation or the like results in improvement in transparency but also deterioration in hardness, as the film becomes more organic.
Research and development of carbon nitride film is in progress recently, but the film is still not better in hardness and other properties than conventional carbon-based thin films such as diamond film and diamond-type carbon film. The harder and denser film also requires heating at a temperature of around 1,000° C. and larger discharge power during deposition. However, application of such a method of forming a film at high temperature under high-energy discharge conditions particularly to organic photoreceptors that are vulnerable to heat and discharge is difficult, and thus, the method is impractical.
Accordingly, conventional carbon-based thin films are still insufficient as the surface layer of a photoreceptor, from the points of both hardness and transparency. On the other hand, hydrogenated amorphous silicon carbide films (a-SiC:H) are superior concerning this point. However, such a film often causes image blurring and image deformation due to deposition of discharge products or the like, and thus, it is necessary to use a drum heater for prevention of these problems. In addition, although hydrogenated nitride semiconductors are superior in hardness and transparency, they are also inferior in water resistance and practicability in a high-humidity environment.
In addition to the methods of forming a surface layer in a gas phase described above, methods of forming a surface layer by coating have been proposed. Among them, for improvement in abrasion resistance, use of a polymer compound having siloxane bonds in the surface layer is known. However, a surface layer of such a material is softer than the surface layer formed in a gas phase. Thus, the surface adhesiveness of the layer gradually increases over time, when subjected to abration after damage occurs on the photoreceptor surface, causing the problem of adhesion of toner on the photoreceptor surface resulting in shortening of the life of the photoreceptor.

Electrophotographic photoreceptor, and process cartridge and image-forming apparatus using the same


N images in a respiratory cycle which are radiographed in year P are input, and binary lung field images are extracted from the respective front chest images. Lung field areas S and lung field heights are then calculated. In forming area and height variation waveforms, regions of the N input images are obtained and plotted. Each image is determined as an image belonging to the inspiration mode or expiration mode. The respective images are sorted and stored. Similar processing is performed for N images in a respiratory cycle which are radiographed in year P+1, and the resultant images are stored. Difference images are obtained from the basic images radiographed in year P+1 and the reference images radiographed in year P for each mode by image analysis, thereby extracting changes over time.

Recently, there has been developed a system which takes radiographic images of an object by using a large-area semiconductor image sensor. This system has the practical merit of being capable of recording images over an extremely wide radiation exposure range as compared with a conventional radiographic image system which uses silver halide radiography.
That is, the semiconductor image sensor reads X-rays in an extremely wide dynamic range as electrical signals by using a photoelectric conversion means, and converts the electrical signals into digital signals. These digital signals are processed to output radiographic images as visible images to recording materials such as photosensitive materials and display devices such as CRTs, thereby obtaining good radiographic images even if radiation exposure dose varies to some extent.
In radiography using this semiconductor image sensor, kymography which radiographs the lungs along with respiration in the lung field portions is expected to provide new pathological information in place of conventional pathological diagnoses mainly using still images. A radiographic image processing apparatus which can obtain dynamic chest images suitable for diagnosis is disclosed in Japanese Patent Laid-Open No. 2003-290193. In this case, "radiographs the lungs along with respiration" means to radiograph the lungs from a sufficiently expanded state to a sufficiently contracted state so as to obtain moving images; radiography preferably includes one cycle from an expansion phase to a contraction phase of the lungs.
With regard to front chest images radiographed in medical examination and the like, differences between two images radiographed at a time interval are calculated. The effect of obtaining differences over time is that the manner in which a morbid portion changes between the two images can be clearly expressed. With this operation, an improvement in diagnosis by a doctor can be expected. Japanese Patent Laid-Open No. 2003-174590 discloses a method of efficiently generating a difference image from two high-resolution still images radiographed at a time interval. In general, however, conventional chest radiography is generally performed while the breath is held; images which have been provided for time-varying difference processing are still chest images radiographed while the breath is held.
As described above, radiography using a semiconductor image sensor can be continuously performed along with respiration. However, there has been known no difference processing technique between radiographic images radiographed during respiration at a time interval.
Realizing difference display of even a plurality of sets of respiratory moving images radiographed at a time interval without making the object hold his/her breath makes it possible to explicitly display a change in disease. This improves diagnosis accuracy. When a morbid portion overlapping a rib occurs at the time of maximum respiration, since the relative positional relationship between the rib and the lung changes during respiration, the morbid portion can be observed at a specific time point during respiration in some cases.
In chest still image radiography, a patient is generally radiographed while he/she inhales most deeply and holds his/her breath in accordance with an instruction from a radiographer. Therefore, a phase in a respiratory cycle is specified. In contrast to this, when chest moving images are to be obtained by radiography along with respiration, it is difficult to apply X-rays upon specifying a phase in a respiratory cycle.
As a method of applying X-rays upon specifying a phase in a respiratory cycle, a sensor which detects respiration may be additionally used. In this case, however, a tool must be attached to the patient, and radiography becomes complicated.
In addition, normal respiration is performed unconsciously, and respiratory cycles are relatively stable which the object is at rest. On the other hand, at the time of respiratory radiography, it is preferable for an object to take a deeper breath than normal in order to improve diagnostic performance. In this case, however, respiratory cycles greatly vary in radiographic operations as compared with the case of unconscious respiration. Therefore, the difference method for chest still images cannot be simply applied to such operation.

Radiographic image processing method and apparatus


A leave-on oxidizing solution useful for permanent waving of hair containing water, an oxidant which is capable of being left on the hair and dried on the hair without damage to the hair, and an acidic agent to provide the solution with a pH value of less than about 7. The use of the leave-on oxidizing solution decreases the amount of time required for carrying out a permanent waving of hair process.

This invention relates to a "leave-on" oxidizing solution for use in the permanent waving ("permiting") of hair and to a process for permanent waving of hair.
Generally, permanent waving of human hair involves a reducing step and an oxidation step. The reducing step involves application of a reducing solution to hair to chemically break sulfur to sulfur or disulfide cystine bonds occurring naturally in human hair. The disulfide cystine bonds in human hair maintain the hair shape or configuration. While the disulfide cystine bonds are broken, the hair can be rearranged into a different configuration. The oxidation step involves application of a neutralizing solution to restore the disulfide bonds in the new rearranged configuration.
A reducing agent in the reducing solution chemically breaks the disulfide bonds in the hair. Examples of reducing agents useful in reducing solutions include cysteamine, esters and salts of thioglycolic acid, cysteine and thiolactic acid. Typical examples of reducing agents and conventional reducing solutions are taught in U.S. Pat. Nos. 5,260,054 and 5,332,570.
An oxidizing agent in the neutralizing solution reform the disulfide bonds in their new "curled" formations. Examples of oxidizing agents useful in neutralizing solutions include bromic acid salts, perboric acid and hydrogen peroxide. Typical examples of oxidizing agents and conventional neutralizing solutions are taught in U.S. Pat. Nos. 5,277,206; 5,080,890 and 5,051,252.
In traditional permanent waves a conventional neutralizing solution used to rebond keratin disulfides, applied after reduction to rolled hair, is left on the hair for only about five minutes and then is thoroughly rinsed off the hair. It is well known that if a conventional neutralizing solution is left on the hair, it can cause damage to the hair. Damage to the hair is qualitatively seen as hair color lightening; damage to hair is quantitatively seen as an increased amount of cysteic acid. The rinsing of the conventional neutralizing solution off the hair is critical to keep hair damage to a minimum. It would be desirable to provide a new oxidizing solution which can be applied after a reduction step to rolled or unrolled hair and left on the hair without having to rinse the oxidizing solution from the hair and without the oxidizing solution causing damage to the hair.
Under normal circumstances, traditional perms may take from 1 1/2 to 3 hours and follow a strict standard procedure. The process steps of the known permanent wave process include for example:
(1) shampooing hair for about 5 minutes; PA1 (2) wrapping the hair on rods which takes about 30 to 90 minutes; PA1 (3) applying a reducing solution on the wrapped hair and processing for 20 to 40 minutes; PA1 (4) rinsing off the reducing solution for about 5 minutes: PA1 (5) blotting water from the hair on the rods for about 3 to 5 minutes; PA1 (6) applying a neutralizing solution to the hair on the rods and waiting about 5 minutes; PA1 (7) rinsing off the neutralizing solution from the hair for about 5 minutes; and PA1 (8) removing the rods from the hair and styling the hair for about 10 to 30 minutes.
It would be desirable and economically advantageous to a stylist to use a permanent wave process that allows the stylist to complete a permanent wave service with identical curl results as traditional perms in significantly less time. Of course, the more clients a stylist can see in a day, the more money the stylist can make. Thus, there is an incentive for those in the art to continuously seek improvement to the permanent wave process.

Leave-on oxidizing solution for permanent waving of hair and a process for permanent waving of hair


A method prepares a computer program for operation in a computer supply system that supplies portions, or program units, of program code or program data of the computer program as the program needs the portions. The method includes defining a program unit of the program and removing the program unit from the program, thereby producing a program skeleton that is missing the program unit. The method further includes inserting instructions in place of the program unit in the program skeleton. The instructions are operative to request the program unit when the program skeleton encounters the instructions. An information structure includes a program skeleton of a program. The program skeleton is missing a funclet of the program, but includes a placeholder in place of the funclet. The program skeleton additionally includes instructions in place of the funclet. The instructions are operative to request the funclet when the program skeleton encounters the instructions.

Computer systems often involve downloading applications and data from a server system for use on a client system. The applications or data may be downloaded only once and then stored on the client computer or they may be downloaded each time the application or data is used. In present application download systems, the client computer initiates a launch mechanism for a desired application, and the compressed bits for the entire application are streamed down from the server and onto the client system. The bits are then decompressed, installed, and executed. Such systems allow no overlap between download time and the execution. The client computer waits until the entire application has been downloaded before beginning execution of the program. Also, a client computer utilizes only about twenty percent of an application's total size during a typical user scenario. Thus, about eighty percent of the downloaded application code and data is unnecessary. While applications are typically cached after they are initially downloaded, the first time download wastes significant bandwidth resources. Also, the time for starting up many applications is extremely long for clients without high-speed connections to servers.
Some systems have used a process called paging, in which an application is split into pages of equal size and each page is downloaded as it is needed by the application. However, such systems often require download of code and/or data that is unnecessary because it happens to be on the same page as the requested code or data. This again wastes bandwidth resources and time. It may also have adverse effects on the operation of the application because the downloaded pages are not arranged in a logical manner.

Preparation for software on demand system


Methods for controlling lasers or other light emitting devices to compensate for performance degradations due to temperature changes and aging without disrupting the transmission of information are presented. Disclosed embodiments describe various methods of applying mathematical models and digital signal processing algorithms to continuously calculate and execute precise output power adjustments. A synthesized test signal is injected into the normal data stream is applied to the laser system. The magnitude of the test signal is sufficiently small that it is buried in system noise and will not alter the noise margin of the signal or the transmitted data. Micro-detection, recovery and digital signal processing of the embedded test signal produces precisely monitored output power and modulation amplitude measurements used to accurately adjust performance characteristics regardless of temperature or age.

1. Field
The presently disclosed embodiments relate generally to laser control, and more specifically to laser performance compensation for aging and temperature changes.
2. Background
Lasers are increasingly used in systems such as high speed communications links, fiber optic channels and medical diagnostics. Market trends demand increased levels of reliability and performance in laser systems. Lasers having signals with accurate output power and signal amplitude are required to meet these performance demands.
Individual lasers exhibit significant variations in performance characteristics when they are newly manufactured. Additionally, all lasers substantially degrade in performance with age and changes in temperature. Performance degradation causes a reduction in output power and signal strength, resulting in decreased Signal to Noise Ratios (S/Ns) and Extinction Rates, as well as increased Bit Error Rates (BERs).
Communications receivers require that signals maintain acceptable signal strength and reliable operating parameters. In order to generate transmission signals that meet receiver requirements, lasers must be adjusted to compensate for individual variations and performance degradations occurring over time.
Various conventional methods are used to compensate for changes in laser performance characteristics. Conventional performance compensation methods have drawbacks such as communication disruption and non-optimal output power adjustments. Non-optimal power adjustments may produce inaccurate output signals that are difficult to receive, and frequently overdrive the laser, reducing its life.
Before adjustments can be made for performance degradations caused by aging and temperature changes, output power and temperature must be accurately monitored. The output power of many lasers available today is monitored with photodiodes that are integrated with the laser in a single package. The photodiodes may also be a component of an integrated circuit that is associated with the laser's driver or a Vertical Cavity Surface Emitting Laser (VCSEL) array. For economic reasons, it is common to utilize very slow photodiodes for monitoring the laser output. In some cases the photodiodes exhibit a frequency response that is several orders of magnitude lower than the frequency response of the laser. Photodiodes with frequency responses that are slower than the lasers they monitor can reliably measure the laser's average power output, but pose a problem in determining the amplitude of the optical pulses for transmitting information. The amplitudes of optical pulses cannot be measured because the photodiode will not generate significant output in response to the Alternating Current (AC signal) output representing data transmission.
In digital communications, it is necessary to monitor the amplitude of the optical pulses in order to distinguish the transmission of a logical one from the transmission of a logical zero. In both analog and digital communications, the magnitude of the optical signal represents the strength of the signal and has a direct impact on signal to noise ratio and transmission reliability. Because sensing power output with low frequency response photodiodes permits only the average power of the laser, rather than the amplitude of data transmission light pulses to be monitored, accurate power output feedback information is not available to adjust the magnitude of optical pulses representing the data. Without accurate amplitude feedback information, output power cannot be properly controlled, causing the Optical Modulation Amplitude, Extinction Ratio and BER to degrade with temperature changes as well as aging.
To perform an accurate power measurement with a slow photodiode, an input power signal must be maintained at a fixed power level causing the system to produce a constant value of light output, which is always equal to the measurable average power value. Since the slow photodiode can't be relied upon to determine the output power of a high frequency signal, other methods have been employed. For example, one method commonly used consists of applying a signal with known amplitude to the laser transmitter while a measurement is made of the resulting output power with an instrument instead of a photodiode. The measurement instrument used is one that can respond to high frequency of light power transitions. This procedure disrupts the signal transmission preventing the transmitter from sending information over the communications channel while adjustments are carried out. Disruption in communication is contrary to the goals of high reliability and 100% up-time in present systems.
Another example of an intrusive power adjustment method is an approach that relies on the application of a tone signal to the laser. The tone is recovered by the monitor photodiode and the recovered signal used to determine changes in laser performance. This method is disadvantageous because, again, the tone disrupts the transmitted signal because the magnitude of the tone signal is of similar magnitude to the magnitude of the transmitted signal. Disruption also causes a significant reduction of the noise margin, which renders this approach inaccurate.
Temperature sensors are commonly utilized to determine when performance adjustments are appropriate due to changes in temperature. Conventional reliance on temperature sensors is also problematic. Temperature sensors, unlike photodiodes, are not commonly integrated with laser or driver devices. The temperature sensor must be mounted at a location external to the laser itself, producing a measurement that is poorly correlated to the actual operating temperature of the laser. The problem is then compounded when inaccurate temperature measurements are used as indexes to determine power adjustments from equally unreliable look-up tables.
Look-up tables are created at the factory for each laser manufactured. Each laser must have its own look-up table because the performance characteristics of each unit differ with variations in constituent parts and manufacture. This method of creating temperature lookup tables requires a costly process on the production line to heat each laser in an environmental chamber at incremental temperatures. Large numbers of test temperature samples produced by small temperature increments, which are necessary for accurate interpolation, increase the production cost. The table is populated with a bias and modulation current for each temperature tested, unique to the particular laser. Even this labor-intensive effort cannot produce an accurate table because the table cannot compensate for aging. Aging cannot be predicted ahead of time with the required level of individual precision to create a table of aging values for a given laser. In some cases, Manufacturers resort to tightening the performance specifications for the laser system so it will still perform adequately after aging degradation. The result of the tightening of the specification is a lower manufacturing yield for the components used in the laser system, which increases costs.
Conventional methods of compensating for degradations in laser output power are inadequate because temperature and output power measurement methods rely on external physical devices that produce inaccurate feedback information. Costly labor intensive look-up tables do not produce reliable results because temperature indexes are poorly correlated to actual laser operating temperatures, and the effects of aging cannot be accurately predicted for individual lasers. Thus, there is a need in the art for improved methods of laser performance monitoring and compensation, which do not employ external measurement components and inaccurate lookup tables or disrupt transmitted data throughput.

Method and apparatus for digital signal processing enhanced laser performance compensation


A resin part, wherein the resin part has an asymmetrical shape in a thickness direction, so that a portion in which an increase in internal temperature by heating is relatively quick is positioned closer to one end of the resin part in the thickness direction while a portion in which an increase in internal temperature by heating is relatively slow is positioned closer to the other end of the resin part in the thickness direction, wherein the resin part has an asymmetrical shape in a width direction, so that the portion in which the increase in internal temperature by heating is relatively quick is positioned closer to one end of the resin part in the width direction while a portion in which an increase in internal temperature by heating is relatively slow is positioned closer to the other end of the resin part in the width direction.

For example, a helical shrinkable tube formed by shaping a band plate-shaped resin in a helical fashion is taught by, for example, Japanese Laid-Open Patent Publication No. 2002-330517. The shrinkable tube may be configured to contract when the shrinkable tube is heated in a condition in which it is wrapped around an electrical wire bundle. Therefore, the helical tube can be wrapped around the electrical wire bundle in close contact therewith.

Resin parts and manufacturing method of resin parts


The present disclosure is directed to communication systems and more specifically to communication devices having encoder and/or decoder blocks employing Low Density Parity Check Convolutional Codes (LDPC CCs). According to exemplary embodiments, improved LDPC CC techniques are disclosed to construct the syndrome former of an LDPC-CC code in a systematic way based on desired Rate (b/c), Memory (ms) and Period (T) while achieving specific Degree Distribution (dv and dc), Girth, and ACE constraints (nACE, dACE) for a desired configuration.

The LDPC CC process utilizes a transposed parity check matrix (also called "syndrome former") HT. This matrix is characterized by sub-matrices HiT(t), each of size c×(c−b), where b/c is the desired rate of the code, b is equal to the number of information bits per encoding time instance and c is equal to the number of code bits per encoding time instance.
Typically, a transposed parity check matrix in LDPC-CCs is semi-infinite. Due to the special characteristics of LDPC-CC transposed parity check matrices, their semi-infinite nature and structure, periodically changing matrices are used in practice.
The same non-zero elements in the matrix, called connections, are repeated after a period T, and therefore only T time instances are needed to fully describe an LDPC-CC matrix. In these T time instances all different variable node connections and check node connections are present.
The largest i such that HiT(t+i) is a non-zero matrix for some t is called the syndrome former Memory ms. Each group of c consecutive rows of the syndrome former corresponds to a time instance and is called a "phase".
Conventional LDPC CC techniques do not provide a systematic way to construct the syndrome former based on desired Rate (b/c), Memory (ms) and Period (T) while achieving specific Degree Distribution (dv and dc), Girth, and Approximate Cycle Extrinsic Message Degree (AC EMD or ACE) constraints (nACE, dACE) for a desired configuration.
It is desirable for encoders and decoders employed in communication systems and devices and which rely on LDPC CCs to be configurable with a broader range of adjustable parameters than previously possible.

Time-varying low-density parity-check convolutional codes


A regulable dashpot with shock-absorption force controls, especially intended for motor vehicles, with at least one flow-regulating system including one or more shock-absorption components for the compression phase and/or for the decompression phase. The object is to allow the dashpot to shift continuously between the hard and soft phases, whereby the valve-adjustment intervals can be varied at intervals that are not unnecessarily short or even unattainable. At least one valve assembly is accordingly supplied with variable flow impedance by a regulating valve (5 or 6).

The present invention concerns a regulated dashpot with shock-absorption force controls, especially intended for motor vehicles.
Regulated hydraulic dashpots with flow-regulating system that shift back and forth between compression and decompression phases in operation are known. Dashpots of this genus are described in German 3 803 838 C2 for instance.
There is a drawback to such dashpots in that their design permits them to shift only suddenly between the hard and soft phases, limiting the range of control. The comfortability of the ride can be increased only to a limited extent.
The object of the present invention is accordingly a dashpot of the aforesaid genus that can shift continuously between the hard and soft phases, whereby the valve-adjustment intervals can be varied at intervals that are not unnecessarily short or even unattainable.

Regulated dashpot with shock-absorption force controls


A single-walled carbon nanotube-based planar photodetector includes a substrate; a first electrode and a second electrode disposed on the substrate and spaced apart from each other; a plurality of single-walled carbon nanotubes, each of the plurality of single-walled carbon nanotubes contacting the first electrode and the second electrode; and an adsorbent attached to a surface of at least one of the plurality of single-walled carbon nanotubes, wherein the adsorbent is capable of doping the at least one of the plurality of single-walled carbon nanotubes by photo-excitation.

1. Field
The present disclosure relates to a single-walled carbon nanotube-based planar photodetector that uses an adsorbent and has improved light detection speed and light detection sensitivity.
2. Description of the Related Art
Single-wall carbon nanotubes (SWCNTs) have superior electric characteristics, such as high field-effect mobility, ballistic transport, and high compatibility with high-k dielectric materials, and may be made into an electric field transistor that would enable the production of high speed field-effect transistors superior to the currently existing silicon-based devices. In addition, their unique optical properties, such as band gap tunability, may enable the tunable emission and detection of specific wavelengths of light.
A photodetector detects an optical signal and converts it to an electric signal. The photodetector may be a vertical photodetector in which two electrodes are arranged parallel to the light's incident direction or a horizontal photodetector in which two electrodes are arranged vertically with respect to the light's incident direction. The horizontal photodetector may be referred to as a planar photodetector.
Many investigations have been made regarding the use of a SWCNT as a horizontal photodetector. However, when carbon nanotubes are formed into a network structure between two electrodes, the mobility of carriers may be reduced as the result of the existence of various trap sites, such as junctions, impurities, and the like. between the carbon nanotubes.

Single walled carbon nanotube-based planar photodector

The Board of Trustees of the Leland Stanford Junior University


A method and apparatus to segment video data files within a video distribution system to facilitate the transfer of the video data files from a file server computing system to client computing system within a video distribution system. The data files are fragmented as a function of demand for the data files, size of each data file of the plurality of data files, amount of retention space available on each of the plurality of data storage devices, and available bandwidth for communication with the client computing systems.

1. Field of the Invention
This invention relates to the field of transferring Digital Video Disk (DVD) or Broadcast quality video data objects over a packet switched network in such a way that the video is played in a smooth (not jerky) manner. Further, this invention relates to the video distribution systems and methods for segmenting video data objects into multiple files to facilitate the transfer of the video data objects.
2. Description of Related Art
In the past video streaming servers required, that a file be fully present before the server could start streaming the file. This imposed a considerable restriction as typical DVD or broadcast quality videos may be several Gigabytes in size and thus imposed a large latency before a viewer could start viewing a video.
Video is the most dominant medium in entertainment and is rapidly becoming a critical part of computing as well. Video is often used in applications such as virtual reality gaming, for example, to mimic personal or virtual environments, increasing an application's appeal and usability. Video has a large information carrying capacity and is heavily used in capturing and conveying complicated situations such as news events, live interviews, scientific experiments, tourist attractions, and many others.
With the increasing availability of high bandwidth networks, video on-demand applications are gaining popularity on global digital communications networks such as the Internet as well as private and corporate digital communication internal networks commonly referred to as Intranets. Example applications include online training, news broadcasts, educational programming, corporate information, and virtual seminars directly to every desktop computing system or workstation. Similarly, video kiosks can be set up in enterprises and university campuses to display live video and up-to-the-minute news, without ever needing an on-site upgrade.
Video data files, however, occupy huge amounts of space on computers. It requires about 10 MB to store one minute of video in most standard compression and decompression video formats, including Motion Picture Experts Group standard MPEG-1, the Apple Computer Inc. Indeo, Intel Corp. QuickTime, and Super Mac, Inc Cinepak. That translates into 1.2 GB of space for two hours of video, the length of an average feature film. These tremendous storage requirements make effective on-demand sharing of video data files at least as important as conventional file sharing.
However, conventional file servers do not address video's unique requirements and cannot effectively support video sharing. Full-motion video, inherited from analog TV, is a sequence of images played out at constant intervals. The two most common analog video formats are the National Television Standards Committee (NTSC), used in the United States and Japan, and Phase Alternation Standard (PAL), used in Europe. NTSC plays video at 30 frames per second, while PAL plays it at 25 frames per second. The sequence of images in a video clip must be relayed at a constant interval, or else the perceptual quality degrades rapidly: the motion jumps and the sound breaks. This rigid periodic timing property is referred to as the isochronous requirement. Referring now to FIG. 1, conventional file servers 10 are designed for minimal transfer latency. Files 15 are thus transferred to maintain the minimum latency and are transferred as quickly as possible. The files 15 will be interleaved with other digital communication traffic on the network and thus non-isochronously. Without explicit mechanisms to ensure isochronism, delivery rates are irregular, resulting in erratic playback quality at the client computing system 20.
To avoid erratic playback, the usual approach is to download whole files 15 from the server 10 to the client computing system 20 before starting video playback. This approach results in unacceptable delays for most video data files, which are large. For example, even with transfer rates as fast as 1.5 Mb/second, the initial start-up delay is 60 seconds for a one minute video clip.
It is thus desirable to deliver video streams isochronously, as depicted in FIG. 2, so that video playback is guaranteed to have smooth motion and sound. The file server 10 must now transfer or stream the files 25 such that the time between each section of the file is transferred in a time period of τ. The even interval allows the file 25 to arrive isochronously with the first section to be displayed before any of the remaining sections of the file 25 have arrived at the client system 20. This allows a video clip to begin practically instantaneously.
The rapid advances in the speeds of microprocessors, storage, and network hardware may give a false impression that video on-demand (VOD) solutions do not need special purpose video streaming software. Video streaming as shown in FIG. 2 allows efficient playback of full motion videos over networks with guaranteed quality using isochronous timing.
When an operating system's default file transfer mode is used to stream a video data file, faster hardware may accelerate the operating system's transfer rate, but this improved hardware still cannot change the fundamental, erratic behavior of a file transfer as shown in FIG. 1. By default, the file transfer process does not respect the isochronous nature of a video stream. This typically results in a jerky and poor-quality playback of a video stream. The dominant factors of a system's overall streaming performance are the higher level client/server and networking processes, and are not the raw power of the low level physical devices.
U.S. Pat. No. 6,101,546 (Hunt) describes a method and system for providing data files that are partitioned by delivery time and data type. A file is logically partitioned into data channels where each data channels holds a sequence of data of a particular data type. The data channels are logically partitioned into delivery times. The format of the file explicitly sets forth the synchronization between the data channels and the delivery times of data held within the channels. The file format is especially well adapted for use in a distributed environment in which the file is to be transferred from a server to a client. Channel handlers are provided at the client to process respective data channels in the file. The channel handlers are data type specific in that they are constructed to process data of an associated data type. The data in the file may be rendered independently of the delivery time of the data.
U.S. Pat. No. 6,018,359 (Kermode, et al.) illustrates a system and method for multicast video-on-demand delivery system. The video-on-demand system divides video data files into sequentially organized data segments for transmission and playback. Each segment is repeatedly transmitted in a looping fashion over a transmission channel. The rate of transmission is equal to or greater than the playback rate, and the lengths of the segments are chosen such that:                (i) the receiver tunes into no more than a fixed number of channels (preferably two) at any one time;        (ii) the receiver tunes into a new channel only after an entire segment has been received from a previous channel; and        (iii) until a maximum segment length is attained, data is received from no fewer than two channels.The segments are sequentially presented even as new segments are being downloaded. When the display rate is equal to the transmission rate, it is found that the foregoing conditions are satisfied when the relative lengths of the segments form a modified Fibonacci sequence.
U.S. Pat. No. 5,930,473 (Teng, et al.) discloses a video application server for mediating live video services. The video application server is to be used in a network including source clients and viewer clients connected to one or more shared transmission media. A video server is connected to one of the transmission media and is operative to control the broadcast and storage of multiple live or previously stored video streams. The control may be provided via remote procedure call (RPC) commands transmitted between the server and the clients. In one embodiment, a video presentation system is provided in which a video stream from a source client is continuously broadcast to a number of viewer clients. One or more of the viewer clients may be authorized by the source client to broadcast an audio and/or video stream to the other clients receiving the source video stream. In another embodiment, a multicast directory is provided to each of a plurality of viewer clients by transmitting directory information in a packet corresponding to a predetermined multicast address. The multicast directory indicates to a particular viewer client which of a number of video programs are available for broadcast to that client.
U.S. Pat. No. 6,101,547 (Mukherjee, et al.) describes an inexpensive, scalable and open-architecture media server. The multi-media server provides client systems with streaming data requiring soft real-time guarantee and static data requiring a large amount of storage space. The servers use a pull-mode protocol to communicate with client systems through a real-time network. Separate data and control channels enhance the soft real-time capability of the server. The data channel conforms to an open standard protocol such as such as Transmission Control Protocol (TCP), User Datagram Protocol (UDP), or Real-time Transport Protocol (RTP). A switched data link layer for the control channel permits separate intrahost control messages that may be multicast and broadcast. The distributed file system selects a specific data block size based upon the compression technique employed to enhance soft real-time guarantee. A hierarchical data structure combined with merging empty data blocks minimizes disk fragmentation. Data blocks are striped across multiple disks to improve disk utilization. A local buffer and a queue for both read and write requests provides support for simultaneous read and write data streams.
U.S. Pat. No. 5,805,821 (Saxena, et al.) teaches a video optimized media streamer user interface employing non-blocking switching to achieve isochronous data transfers. The media streamer includes at least one control node; a user interface having an output coupled to at least one control node; at least one storage node for storing a digital representation of at least one video presentation; and a plurality of communication nodes each having an input port for receiving a digital representation of at least one video presentation therefrom. The video presentation requires a time T to present in its entirety, and is stored as a plurality of N data blocks. Each data block stores data corresponding to a T/N period of the video presentation. Each communication nodes further has a plurality of output ports for outputting a digital representation. A circuit switch is connected between the at least one storage node and the input ports of communication nodes for coupling one or more input ports to at least one storage node. The user interface includes a capability for specifying commands for execution, and the at least one control node is responsive to individual ones of the commands for controlling at least one of the at least one storage node and at least one of the plurality of communication nodes, in cooperation with the circuit switch, so as to execute a function associated with individual ones of the commands. The commands may include video cassette recorder-like commands that include commands selected from a group that includes a Load command, an Eject command, a Play command, a Slow command, a Fast Forward command, a Pause command, a Stop command, a Rewind command, and a Mute command. The commands may also include commands selected from a group that includes a Play List command, a Play Length command, and a Batch command. A synchronous application program interface (API) is provided for coupling, via the user interface, a user application program to at least one control node. The API includes Remote Procedure Call (RPC) procedures.
U.S. Pat. No. 5,550,577 (Verbiest, et al.) illustrates a video on demand network, including a central video server and distributed video servers with random access read/write memories. The video on demand network transmits video signals to user stations pursuant to the receipt of control signals issued by these user stations. In order to optimize the retrieval costs, this video on demand network maintains a large video library in a central video server and stores locally popular video signals in a plurality of local distributed video servers from which the latter video signals are transmitted to the user stations. The video signals provided by the local distributed servers are updated from the central server based upon the changing popularity of the video signals. The video on demand network of Verbiest proposes in particular to store the video signals in the local distributed servers in random access read/write memories, e.g., electronic RAMs, magnetic or optical disks from which the video signals can flexibly be supplied on-line to the user stations and to store the video signals in the central server in sequential access memories, e.g. Digital Audio Tapes (DAT) and CD-ROMs (CDR), providing cheap mass storage.
"Performance Evaluation of QuickVideo OnDemand (QVOD) Server," InfoValue Computing, Inc. Technical Report IV-TR-QVOD-1999-07-1-1, Jul. 8, 1999, InfoValue Computing, Inc., Elmsford, N.Y. describes a video on-demand system developed for high performance, effective and flexible, network-based, on-demand sharing of videos. QuickVideo On Demand provides streaming throughput for broadband applications Further, QuickVideo On Demand allows a linearly scalable clustering mechanism which provides support for higher throughputs, if required. QuickVideo On Demand supports all video formats, codecs, networks and applications, and is compatible with any open application platform.
"Network Video Computing Via QuickVideo Suite," InfoValue Technical White Paper, InfoValue Computing, Inc., Elmsford, N.Y., 1999, describes Network Video Computing the core of which is video streaming. Video streaming allows the efficient playing of full-motion video content over networks with guaranteed quality. The rigid timing property of full motion video is referred to as the isochronous timing. File servers are designed to minimize transfer latency during conventional network transfers, and are insensitive to video's unique timing requirement. As a result, delivery rates are irregular and produce erratic playback as described above. Video streaming technologies are real-time network transfers that maintain the video's critical timing property throughout the entire delivery period, as depicted in FIG. 2. This white paper describes the open architecture with a streaming core.
"Web Distribution Systems: Caching and Replication" Chandbok, Ohio State University, 1999, found http://www.cis.ohio-state.edu/˜jain/cis788-99/web_caching/index.html, 8/15/00, provides an overview of the current techniques for caching and replication of digital data on computer systems interconnected through a global or local digital communication network. Refer now to FIG. 3 for a summary of caching in large distributed digital processing networks. Multiple server computing systems 100a, 100b, . . . , 100f are high performance computing systems such as the IBM Corporation RS-6000-SP, The Sun Microsystems, Inc. Enterprise 10000 Server, the Hewlett-Packard Netserver AA-6200, or other server systems. The computer systems 100a, 100b, . . . , 100f are each connected to multiple storage devices 105a, 105b, . . . , 105r. The storage devices 105a, 105b, . . . , 105r are magnetic disk devices, compact disk read only memory (CD-ROM) "juke boxes," or tapes drives. A group of the server systems 100a, 100b, 100c or 100d, 100e, 100f are respectively interconnected through the digital communications cluster network 110 and 115 to form the server cluster 1 120 and the server cluster 2 125. The server cluster 1 120 and the server cluster 2 125 may be resident with in the same enterprise data center or placed at different geographical locations either within the enterprises or even in different enterprises.
The cluster networks 110 and 115 are connected respectively to the network routers 130 and 135. The network routers 130 and 135 are further connected to a public or global digital communications network 155. The global network 155 may be the public Internet or an enterprise's private Intranet.
The server computer systems 100a, 100b, . . . , 100f contain database information systems, storage for files such as audio or video data files, and other data files to accessed by large numbers of people either publicly or privately within an enterprise through the client systems 150a, 1500b, 150c.
Edge servers 140a, 140b, 140c are connected to the global network 155 and thus provide access portals for the client systems 150a, 150b, 160c to the global network 155 to communicate with each other, with other edge servers 140a, 140b, 140c, or with the server computer systems 100a, 100b, . . . , 100f. Each edge servers 140a, 140b, 140c is connected has attached data storage device 145a, 145b, . . . , 145i. The attached data storage device 145a, 145b, . . . , 145i is generally a magnetic disk storage device, but may also include a CD-ROM, magnetic tape, or other storage media.
If a server computer systems 100a, 100b, . . . , 100f has data 160 that is requested by many of the client systems 150a, 150b, 150c, the network traffic to the server computer system 100a may to great for either the global network 155 or the cluster network 110 to carry and maintain a reasonable quality of service. Quality of service in this context means that the original data 160 is transferred repetitively relatively quickly and if the original data 160 is audio or video data files, that the isochronous nature of the transfer of the data is maintained.
If the server clusters 120 and 125 are separated geographically, it may cost less to maintain the quality of service by placing a copy 165 of the original data 160 in a disk 1051 on a second server system 100d. If the copy 165 of the original data 160 is permanent, it is referred to as being replicated. If the copy 165 of the original data 160 is temporary, it is referred to as cached. As the demand for the original data 160 is increased, it may be desirable to either replicate or cache 170 or 175 the data even within the disks 145b or 145i of the edge servers 150a or 150c.
There are many policies developed regarding which of the original data 160 is replicated or cached 165, 170, or 175. Further, the replacement of cached data 165, 170, or 175 by other data that is demanded more often is known and generally follows a least recently used protocol, where the cached data 165, 170, or 175 that has not been requested is replaced by that is more requested.
U.S. Pat. No. 6,088,721 (Lin, et al.) teaches an efficient unified replication and caching protocol. The protocol provides assurance of consistent replication of objects from a central server to caching servers, for example, over data communication networks such as the Internet. It is an application-layer protocol, which guarantees delivery of objects such as files. This protocol insures that objects sent by a source machine such as a server to any number of destination machines such as caching servers actually arrive at the intended caching servers even when the caching servers are temporarily unavailable, for example, due to failure or network partition.
U.S. Pat. No. 6,061,504 (Tzelnic, et al.) illustrates a video data file server using an integrated cached disk array and stream server computer. The video data file server includes an integrated cached disk array storage subsystem and a multiple stream server computers linking the cached disk storage system to the data network for the transfer of video data streams. The video data file server further includes a controller server for applying an admission control policy to client requests and assigning stream servers to service the client requests. The stream servers include a real-time scheduler for scheduling isochronous tasks, and supports at least one industry standard network file access protocol such as Simple Network Management Protocol (SNMP) and one file access protocol Network File System (NFS) for continuous media file access. The cached disk storage subsystem is responsive to video prefetch commands, and the data specified for a prefetch command for a process are retained in an allocated portion of the cache memory from the time that the cached disk storage subsystem has responded to the prefetch command to the time that the cached disk storage subsystem responds to a fetch command specifying the data for the process. The time between prefetching and fetching is selected based on available disk and cache resources. The video data file server provides video-on-demand service by maintaining and dynamically allocating sliding windows of video data in the random access memories of the stream server computers.
"Network Caching Guide," Goulde, Patricia Seybold Group for Inktomi Corp., Boston, Ma, March 1999, describes the various types of caching approaches and the different ways for caches to be implemented. Implementations vary depending on where the cache is placed, who is accessing the cache, and the quantity and type of content that is being cached. Goulde describes the Inktomi Traffic Server from Inktomi Corporation. The Inktomi Traffic Server is capable of delivering fresh content to large numbers of users around the world from a large number of Web servers around the world.
"Inktomi Traffic Server—Media Cache Option", Inktomi Corporation, San Mateo Ca., 1999, found http://www.inktomi.com, 8/15/00, describes the caching option for the Inktomi Traffic Server to support streaming of video data files.
"Implementing Multiplexing, Streaming, and Server Interaction for MPEG-4" Kalva et al., IEEE Transactions On Circuits And Systems For Video Technology, Vol. 9, No. 8, December 1999, pp. 1299-1312, describes the implementation of a streaming client-server system for object-based audio-visual presentations in general and MPEG-4 content in particular. The system augments the MPEG-4 demonstration software implementation (IM1) for PC's by adding network-based operation with full support for the Delivery Multimedia Integration Framework (DMIF) specification, a streaming PC-based server with DMIF support, and multiplexing software. The MPEG-4 server is designed for delivering object-based audio-visual presentations. The system also implements an architecture for client-server interaction in object-based audio-visual presentations, using the mechanism of command routes and command descriptors.
"New Solution for Transparent Web Caching: Traffic Server 2.1 Supports WCCP," Inktomi Corporation, San Mateo Ca., 2000, found http://www.inktomi.com/products/network/traffic/tech/wccp, 8/15/00 describes the use of the Web Cache Control Protocol (WCCP) from Cisco Systems, Inc. within Inktomi Corporation's Traffic Server.
"API Overview," Inktomi Corporation, San Mateo Ca., 2000, found http://www.inktomi.com/products/network/traffic/tech/wccp, 8/15/00, describes the application program interface tools that are available for the Inktomi Corporation's Traffic Server which allow customization or the Traffic Server's event processing thus allowing manipulation of hypertext transaction protocol (HTTP) transactions at any point in their lifetime.
"Web Cache Communication Protocol v2" Cisco Systems, Inc., San Jose, Calif., found http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120t/120t3/wccp.htm, 8/15/00, describes the protocol that allows the use a Cisco Cache Engine to handle web traffic, reducing transmission costs and downloading time. This traffic includes user requests to view pages and graphics on World Wide Web servers, whether internal or external to a network, and the replies to those requests. When a user requests a page from a web server (located in the Internet), the router sends the request to a cache engine. If the cache engine has a copy of the requested page in storage, the cache engine sends the user that page. Otherwise, the cache engine retrieves the requested page and the objects on that page from the web server, stores a copy of the page and its objects, and forwards the page and objects to the user. WCCP transparently redirects Hypertext Transfer Protocol (HTTP) requests from the intended server to a cache engine.
"A Practical Methodology For Guaranteeing Quality Of Service For Video-On-Demand," Zamora et al., IEEE Transactions On Circuits And Systems For Video Technology, Vol. 10, No. 1, February 2000, describes an approach for defining end-to-end quality of service (QoS) in video-on-demand (VoD) services. A schedulable region for a video server, which guarantees end-to-end QoS, where a specific QoS required in the video client, translates into a QoS specification for the video server. The methodology is based on a generic model for VoD services, which is extendible to any VoD system. In this kind of system, both the network and the video server are potential sources of QoS degradation. The effects that impairments in the video server and video client have on the video quality perceived by the end user is examined.
As described above, video data files may be very large, on the order of 1.2 GB for a two hour movie or video presentation. In the digital communication networks 110, 115, and 155 of FIG. 3, the files are generally formed into data packets for transfer. These data packets may not arrive to a designated client system 150a, 150b, 150c in correct order for processing. This requires reception of the complete file before processing may begin. If the file is an audio or video data file requiring isochronous presentation of the file, the files must be totally received before processing or the files must be segmented or partitioned into portions to allow smaller units of the files to be processed.
U.S. Pat. No. 5,926,649 (Ma, et al.) teaches a Media server for storage and retrieval of voluminous multimedia data. The Media server provides storage and retrieval of multiple data streams in a multimedia distribution system. A given data stream is separated into a plurality of portions, and the portions are stored in a multi-disk storage system with Y disks each having X zones such that the ith portion of the given stream is stored in zone (i mod X) of disk (i mod Y). The number X of zones per disk and the number Y of disks are selected as relatively prime numbers. The stored data are retrieved using Y independent retrieval schedulers which are circulated among the Y disks over a number of scheduling intervals. Each retrieval scheduler processes multiple requests separated into X groups, with the requests of each group accessing the same disk zone during a given scheduling interval. The retrieval schedulers are also configured such that the retrieval requests of a given retrieval scheduler access the same disk during a given scheduling interval. The data stream placement technique in conjunction with the retrieval schedulers provide sequential-like parallel retrieval suitable for supporting real-time multimedia data distribution for large numbers of clients.
U.S. Pat. No. 5,936,659 (Viswanathan, et al.) illustrates a method for broadcasting movies within channels of a wide band network by breaking the communications path into a number of logical channels and breaking each movie up into a number of segments of increasing size. The first segment of each movie is the smallest segment is transmitted in sequence over the first logical channel and repeated. The second segment of each movie which is proportionately larger than the first segment of each movie is transmitted in sequence over the second logical channel and repeated. This is repeated for the total number of segments which equals the total number of logical channels. The segments are broadcast in such a way that, once the first segment is received at a client location, the subsequent segments are also received in time, so that the movie can be viewed continuously.
U.S. Pat. No. 5,973,679 (Abbott, et al.) describes an indexing method for allowing a viewer to control the mode of delivery of program material. By mapping from time to data position, data delivery can begin at any selected time in the program material. The indexing method also provides for controlling data delivery to begin at the beginning of a frame of data. A synchronizing method is provided to minimize a time offset between audio and video data, particularly in environments using groups of pictures.
U.S. Pat. No. 5,996,015 (Day, et al.) describes a method of delivering seamless and continuous presentation of multimedia data files to a target device by assembling and concatenating multimedia segments in memory. The method provides a multimedia server connected in a network configuration with client computer systems. The multimedia server further includes various functional units which are selectively operable for delivering and effecting the presentation of multimedia files to the client such that a plurality of multimedia files are seamlessly concatenated on the fly to enable a continuous and uninterrupted presentation to the client. In one example, client selected video data files are seamlessly joined together at the server just prior to file delivery from the server. The methodology includes the analog to digital encoding of multimedia segments followed by a commonization processing to ensure that all of the multimedia segments have common operating characteristics. A seamless sequential playlist or dynamically created playlist is assembled from the selected and commonized segments and the resources needed to deliver and play the playlist are reserved in advance to assure resource availability for continuous transmission and execution of the playlist. At a predetermined point prior to an end point of each selected multimedia segment, the next selected segment is initialized and aligned in memory in preparation for a seamless switch to the next segment at the end of a previous segment, thereby providing a seamless flow of data and a continuous presentation of a plurality of selected multimedia files to a client system.
U.S. Pat. No. 5,608,448 (Smoral, et al.) describes a hybrid architecture for a video on demand server. The processing requirement at each computing element in a video server for a video on demand (VOD) system is reduced to only those needed for VOD, resulting in a less expensive processor with less memory and, hence, lower cost. A hybrid video server architecture combines the features of massive parallel processor (MPP) and workstation designs. Since it is not necessary to run a parallel relational database program in order to accomplish VOD data distribution, a unique type of switch element that is well matched to the VOD server problem is employed. By matching this switch element technology to an appropriate data storage technique, a full featured, responsive VOD server is realized.
U.S. Pat. No. 6,061,732 (Korst, et al.) describes a data streaming system utilizing an asynchronous technique for retrieving data from a stream server. In an audio/video server blocks of data are read from a storage medium by a reader and supplied to users in the form of data streams. The storage medium comprises a plurality of record-carrier based storage units. A reader reads a batch of data units from a storage unit in a single relative movement of a reading head of the storage unit with respect to the record-carrier of the storage unit. A scheduler controls reading of blocks from the storage medium by determining from which storage unit(s) data unit(s) need to be read for the block and placing a corresponding carrier access request in a read queue. The scheduler extracts for each of the storage units a batch of carrier access requests from the queue and issues the batch to the reader in an asynchronous manner, in response to the reader having substantially completed reading data units for a previous batch for the storage unit.
U.S. Pat. No. 5,414,455 (Hooper, et al.) teaches a segmented video on demand system. In the system for distributing videos, multiple videos are stored on a mass storage device. Each video includes a plurality of frames of digitized video data for playback on a viewing device. The system includes a memory buffer for storing a segment of a selected one of the videos. The segment includes a predetermined number of frames representing a predetermined time interval of the selected video. In addition, the memory buffer including a write pointer and a read pointer. Software controlled servers are provided for witting and reading video data of the selected video to and from the memory buffer, independently, at locations indicated by the write and read pointers to transfer the selected video to the viewing device.

Broadband video distribution system using segments


A freeze concentration method separates the nucleation and the growth processes at least to the extent necessary to enable nucleation and crystal growth to occur at different temperatures. Nucleation, however, is triggered by a sonicator, i.e., ultrasonic radiation. This provides excellent control of the process since the variables of the input sonic energy are adjusted easily. Most importantly, the use of ultrasound permits nucleation at low supercooling. The consequences of this are: an inexpensive plain--as opposed to the more complex and expensive scraped-surface--heat exchanger can be used since the coolant temperature is only slightly lower than that of the solution, preventing ice scaling in the heat exchanger; the higher coolant temperature leads to savings also in the operation costs. In addition ultrasonic nucleators are easily scaled-up to treating the large-volume effluents from industrial plants. The only way to scale-up scraped-surface nucleators is by using multiple nucleators in parallel.

In recent years, tightening of the effluent regulations and increasing community concerns have provided the motivation for further reductions in contaminants, especially the toxic organic chlorinated compounds such as those found in the effluents of pulp and paper mills. As a result, some mechanical process pulp mills are employing zero-discharge technology, while paper mills in Sweden have switched their bleach technology from chlorine-based to a total chlorine-free (TCF) processes.
In the United States, however, most pulp mills are utilizing the Kraft process, which results in effluent volumes being several times higher. In addition, due to the stronger market demand for the high quality paper from the elemental chlorine-free (ECF) process and its lower cost, most of the mills in the U.S. prefer ECF over TCF and a minimum-discharge over a zero-discharge process.
Efforts have been made to improve the ClO.sub.2 bleaching sequence and have succeeded in reducing the TCDD (2, 3, 7, 8-tetrachloro-dibenzo-p-dioxin) in the effluents below its detectable limit (10 parts per quadrillion) and the AOX (adsorbable organic halogens) from 1.5 to 0.3 kg/ton pulp. However, the effect of these reductions on the environment remains uncertain because of the wide differences in toxicity in the hundreds AOX compounds and the extreme toxicity of dioxin. New EPA regulations of 0.272 kg/ton pulp on AOX that will be in effect in 1998, the expected imposition of new and tighter regulations requiring 0.05 kg/ton in fifteen years for AOX in the ECF process due to new toxicological findings, and the competition from the TCF process, necessitates significant reductions of AOX, of specific chlorophenols, and of furans in the effluents from mills employing ClO.sub.2 bleaching.
The traditional technology of wastewater treatment involves evaporation for volume reduction and subsequent biotreatment with a recovery boiler for the destruction of the contaminants. However, this technology is not very efficient for the AOX reduction. Actually, the achieved reduction of AOX to 0.3 kg/ton pulp by the improvement of ECF sequence is close to the limit of the process capability.
AOX is a wide spectrum of organic chlorinated compounds. Many of the compounds are either poorly- or non-biodegradable. The efficiency of AOX removal by biotreatment was found to be 40-50% for effluents from a ClO.sub.2 bleaching unit of a mill. There are reports of 23 to 70% removal of AOX by biotreatment from bleach effluents of mills. It should be also noted that many of these compounds are volatile. In a distillation, AOX will leave with the distillate even if only 10 to 20% is evaporated in a batch experiment. Actually when 90% of the effluent volume is distilled, only half of the AOX remained in the still. Continuous distillation experiments showed that only a third of AOX remained in the bottom product. The actual AOX concentration in distillates from 0-10% up to 80-90% of the effluent volume remained close to a constant value. These results predicted the poor separation of distillate from AOX in the evaporators, which concentrate the bleaching effluent from 0.2-0.3% to 15% by solute weight, and the concentrators, which concentrate it from 15% to 45%.
In other industries, freeze concentration has been used to effectively keep the volatile solute in the concentrate. The concentration of aqueous solutions by freezing the solution and removing the resulting ice has been studied extensively. Generally, however, freeze concentration of fruit juices, like orange and apple juice, and of coffee are the only commercialized industrial processes. These are relatively small volume processes.
The application of freeze concentration to large volume processes such as the desalination of sea water or the waste water or toxic effluents treatment is hindered by technical problems such as the formation of ice scaling on the cooling surface and the plugging of the tubes of the heat exchanger, entrapment of concentrate in the produced ice, and the high refrigeration cost.
The NIRO process, used currently for fruit juice concentration, has solved the technical problems by decoupling the nucleation and the growth processes for ice crystals and controlling them separately. The formation of ice nuclei (nucleation) takes place on the cooling surface of an expensive scraped-surface heat exchanger (VOTATOR). The ice nuclei are then transferred to a crystallizer where they grow.

Process and system for freeze concentration using ultrasonic nucleation useful in effluent processing


The disclosure provides molecules with an affinity for (or an ability to bind to), sialic acid, for use in compositions, medicaments and methods for the treatment of sepsis, its symptoms and sepsis associated pathologies and immune responses.

Sepsis is a life-threatening condition that is most commonly caused by bacteria in the bloodstream, a condition known as bacteraemia. Pathogenic bacteria originating from a primary infection location, such as the lungs or urinary tract, release toxins that can provoke a dysregulation of the innate immune response, leading to host tissue and organ damage1.
Bacterial sepsis is a worldwide problem, generally resulting from nosocomial polybacterial infections, and is responsible for 25% intensive care admissions with a survival rate of around 50%2.
While conventional antibiotics may be effective in killing pathogenic microorganisms in sepsis patients, they can also accelerate the release of pro-inflammatory components causing severe sepsis and shock. Alternative compounds of interest for sepsis therapy include natural occurring antimicrobial peptides (AMPs), which target pathogenic bacteria and fungi by displaying different defense mechanisms such as membrane disruption, with some having immunomodulatory activities4. AMPs mainly function by disabling/killing pathogen without releasing pro-inflammatory agents. However, there are several challenges with the use of AMPs as therapeutics due to their limited pharmaceutical application such as high toxicity in most tissues, as well as the likelihood of microbial resistances. Attempts to design synthetic based AMPs to reduce toxicity and stability issues are in developments.
Multivalent Family 40 CBMs (mCBM40s) target and bind to host cell surface sialic acid receptors with high affinity7,8. These engineered mCBM40s also display immunomodulatory activities when given intranasally either alone, or in respiratory pathogen-challenged mouse models5,9.
Despite the use of antibiotics as a control strategy for bacterial sepsis, the rise in antibiotic resistance by bloodstream bacterial isolates in recent years has highlighted an urgent need for novel compounds, therapies and regimes for the treatment and management of sepsis, its symptoms and pathologies3.


The present invention relates to substrates for biological testing produced from photo-curable epoxy compositions which further include carboxyl-containing monomers such as acrylic acid, 2-carboxyethyl acrylic acid, 4-vinylbenzoic acid, or 3-Acrylamido-3-methyl-1-butanoic acid, or glycidyl methacrylate, etc. The photo-curable compositions may be used to cast films or fabricate beads, magnetic beads, or magnetic beads containing nickel barcodes. The resulting various kinds of films, beads, magnetic beads, or magnetic beads containing nickel barcodes may find use in clinical or biological applications.

1. Field of the Invention
The present invention relates generally to solid substrates for conducting biological assays and more specifically to assay beads (microbeads) and methods for use thereof to carry out multiplexed bioassays. The invention particularly relates to multiplexed bioassays using micro-volume samples, such as protein and nucleic acid analysis. The invention further relates to photo-curable epoxy compositions such as those containing EPON SU-8 epoxy resin (Hexion Specialty Chemicals), EPON 1002F epoxy resin (Hexion Specialty Chemicals), as well as other bi-functional or multifunctional epoxy resins. Preferred photo-curable compositions exhibiting significantly better performance according to the invention further include carboxyl-containing monomers such as acrylic acid, 2-carboxyethyl acrylic acid, 4-vinylbenzoic acid, or 3-acrylamido-3-methyl-1-butanoic acid, or glycidyl methacrylate, and the like. The photo-curable compositions may be used to cast films or fabricate beads, magnetic beads, or magnetic beads containing nickel barcodes. The resulting various kinds of films, micro beads, magnetic beads, or magnetic beads containing nickel barcodes and are useful in a variety clinical or biological applications.
2. Description of Related Art
As current research in genomics and proteomics produces more multiplexed data, there is a need for technologies that can rapidly screen a large number of nucleic acids and proteins in a very small volume of samples. Microarray, DNA chips, and protein chips have drawn a great deal of commercial interest. The assays are typically performed on a planar biochip platform by arraying and immobilizing DNA on a solid support via mechanical printing in the x-y position onto the microscope slide, by piezoelectric ink-jetting or by direct synthesis of DNA on the chip. However, mechanical contact printing is not very desirable because it prints one spot per contact that results in relatively large printing variations from spot to spot or batch to batch, inconsistent spot morphology, misprinting, and slide surface variations, all of which are undesirable for DNA microarray analysis. Further, distributing a small volume of liquid samples over a relatively large chip surface often encounters the problems of insufficient sample amounts or non-uniform distribution over the chip surface. These problems can cause incomplete reactions or very long reaction time.
Micro bead technology potentially overcomes many of the problems of microarray technology and provides better quality control of each probe, flexibility with the assembly of various type and amount of probes in an analysis, and convenience of doing analysis without mechanical printing. Existing micro bead approaches include (1) the incorporation of spherical beads or particles with spectrally distinguishable fluorophore, fluorescent semiconductor quantum dots, and (2) metallic rods with either bar coded color (absorption) stripes or black and white strips. Both fluorescence and barcode strip beads are identified by optical detection in reflective or emissive configuration. The problems of reflection configuration are (1) it is difficult to setup the collection optics in proper position, especially when the bead dimensions are on a micrometer scale, and (2) the light collection efficiency is poor and the barcode contrast is low, especially when micro beads are in the micro flow system. The flow scatters light, which interferes with optical reflection or emissive detection. Further, fluorescent beads, the spectral range and the possible number of spectrally distinguishable labels, however, often limit the potential number of code variations. Many laser light sources are often needed to excite different fluorescent labels. In addition, the validity of the coding signatures is another serious concern, since the incorporated coding elements in some cases may be lost; photo bleached, or interfered spectrally with the analytical signals. In the case of multi-metal (Au, Pt, Ni, Ag, etc) color micro rods, the encoding scheme suffers from the difficulty of manufacturing and the number of colors, based on different metal materials, is limited. Many 1D or 2D bar codes are recognized by their specific image patterns. Optical imaging method is used for recognition of these bar code patterns. Although high speed camera is available for capturing bar code images, pattern recognition is a slow and time consuming process. It often needs special software to analyze the images section by section. Therefore, it is difficult to identify hundreds or thousands of beads in a short time to improve throughput. The following patent documents disclose some of the systems that exhibit some of the deficiencies noted above.
U.S. Pat. No. 6,773,886 issued on Aug. 10, 2004, the entire contents of which are incorporated herein by reference, discloses a form of bar coding comprising 30-300 nm diameter by 400-4000 nm multilayer multi metal rods. These rods are constructed by electrodeposition into an alumina mold; thereafter the alumina is removed leaving these small multilayer objects behind. The system can have up to 12 zones encoded, in up to 7 different metals, where the metals have different reflectivity and thus appear lighter or darker in an optical microscope depending on the metal type whereas assay readout is by fluorescence from the target, and the identity of the probe is from the light dark pattern of the barcodes.
U.S. Pat. No. 6,630,307 issued on Oct. 7, 2003, the entire contents of which are incorporated herein by reference, discloses semiconductor nano-crystals acting as a barcode, wherein each semiconductor nanocrystal produces a distinct emissions spectrum. These characteristic emissions can be observed as colors, if in the visible region of the spectrum, or may be decoded to provide information about the particular wavelength at which the discrete transition is observed.
U.S. Pat. No. 6,734,420 issued on May 11, 2004, the entire contents of which are incorporated herein by reference, discloses an identification system comprising a plurality of identifiable elements associated with labels, the labels including markers for generating wavelength/intensity spectra in response to excitation energy, and an analyzer for identifying the elements from the wavelength/intensity spectra of the associated labels.
U.S. Pat. No. 6,350,620 issued on Feb. 26, 2002, discloses a method of producing a micro carrier employing the shape, size, and color of the carrier as image bar codes for identification. The patent discloses an identification system comprising a bar code is formed on the substrate by photolithography, and then using nickel plates to hot compress the bar code onto the surface of bead to form a microcake-like particle. The bar code pattern can be classified by an imaging recognition system.
U.S. Pub. No. US2005/0003556 A1, the entire contents of which are incorporated herein by reference, discloses an identification system using optical graphics, for example, bar codes or dot matrix bar codes and color signals based on color information signal for producing the affinity reaction probe beads. The color pattern is decoded in optical reflection mode.
U.S. Pub. No. US2005/0244955, the entire contents of which are incorporated herein by reference, discloses a micro-pallet which includes a small flat surface designed for single adherent cells to plate, a cell plating region designed to protect the cells, and shaping designed to enable or improve flow-through operation. The micro-pallet is preferably patterned in a readily identifiable manner and sized to accommodate a single cell to which it is comparable in size.
What is needed is a digitally encoded micro bead that provides for high contrast and high signal-to-noise detection, and that provides for parallel and high-throughput bioanalysis, e.g., of proteins, pathogens, gene expression, single nucleotide polymorphism, nucleic acid-based tissue typing, cell or chromosome sorting, and transcriptional profiling that requires smaller volumes of fluid and rapid assay.
The barcode microbeads or micro pellets are typically fabricated by photo-lithography. Thousands or millions of micro beads or micro patterns can be synthesized on a micro slide, a glass or a silicon wafer. Suitable materials for the fabrication of microbeads include photosensitive photopolymer or so called photoresists, such as EPON 1002F or SU-8 brand epoxy resins. The starting materials can be monomer or polymer, and resulting into cross-linking polymer after UV or photon exposure. Although photopolymers are commonly used in the semiconductor industry, many semiconductor industry photopolymers are not biocompatible because of the difficulty of immobilizing biomolecules, such as proteins, oligonucleotides or cells, on the surface of these materials, especially if long term stability is required for storage. Other problems associated with current photoresists include high auto fluorescence, brittleness, and poor adhesive properties for multilayer formation. More importantly, because the microbeads are suspended in the reaction solution it is desired that all surfaces be bio-reactive. Thus the whole microbead should have the same surface chemical property, unlike a single side surface, such as a film on a glass.
EPON SU-8 epoxy, (Hexion Specialty Chemicals) is a photoresist resin which has been used in microelectromechanincal system (MEMS) for the fabrication of high aspect ratio structure. A solution containing SU-8 resin, photo acid generator, such as triphenyl sulfonium hexafluoroantimonate, and solvent, such as γ-butyrolactone or cyclopentanone is coated onto various substrates, pre-baked to evaporate the solvent, leaving a solid photoresist film of up to several hundred microns thickness depending on the solid content of the solution. By exposing the film through a photo mask to UV irradiation, a pattern is transferred to the photoresist. A high resolution three dimensional negative image of the mask is formed by subsequent immersion into a developer solution. Because the surface of SU-8 has epoxy groups it has hydrophobic properties and presents a limitation to many biological applications requiring specific functional groups. These limitations include challenges in surface wetting, biofouling and limited cell attachment. There remains a need to improve the biocompatibility of such epoxy resins.


A cup part with a top open for containing a dye therein is included, and comb teeth are provided side by side at an upper end surface of the cup part or an inner surface of the cup part. By utilizing the comb teeth, operations of scraping an unnecessary dye off a brush or the like and settling the shape of the brush portion or the like can be facilitated, and hair, dust and the like attaching to the brush or the like can be removed without contaminating hands.

In a barber's shop, a beauty salon or the like, a barber or a hair dresser applies a hair color to the hair of a customer by scooping out the hair color from a cup with a brush or the like with the cup containing the hair color (a hair dye for dying hair) placed near a head of the customer sitting in a chair. Concerning a pair color cup, for example, Japanese Patent Application Laid-open No. 2000-316627 is known.
On applying a hair color, a brush portion at a tip end of a brush or the like is temporarily soaked in the hair color in a cup, then, the brush portion is pressed against a cup upper end portion or the like to scrape off the needless hair color, and after the shape of the brush portion is settled, the hair color is applied to the hair of a customer. With the conventional hair color cup, the problem of dropping a hair color outside the cup by mistake, or of the hair color scraped off the brush portion dropping outside from the cup upper end portion easily occurs when scraping the unnecessary hair color off the brush portion as above, and settling the shape of the brush portion.
Besides, when a hair color is applied to the hair of a customer with a brush or the like, hair (fallen hair or the like), dust and the like sometimes attach to the brush or the like, and in this case, the hair color attaches to hair, dust and the like which attach to the brush or the like, extending off the brush or the like, and therefore, when the hair color is directly applied, the problem that the hair color attaching to hair, dust and the like attaches to the other portions than the hair and scalp, and contaminates the face, skin and clothes of the customer occurs.
In order to avoid such a problem, a barber and a hairdresser remove hair, dust and the like which attach to brushes or the like by hands each time when applying hair colors, but in doing so, the hair colors attach to the hands of the barber and the hair dresser. Besides, there occurs the problem that by touch of the hands to which such hair colors attach, the faces, the skins or the clothes of the customers, or the surroundings are contaminated.


This device (2) for generating ultrasonic waves in a target region of a soft solid, includes at least two ultrasound sources (32), light sources (40) distributed around a central axis (X2) of the device (2), for enlightening a zone of the soft solid via subsurface scattering, and a video camera (50), for capturing images of the zone enlightened by the lighting means. The ultrasound source (32), the light sources (40) and the video camera (50) are mounted on a body of the device (20) and oriented toward a common target zone which includes a focal point of the ultrasound sources (32). A boresight of the video camera is aligned on the central axis (X2).

As mentioned in WO-A-2006/021651, ultrasounds can be used for the treatment of varicose veins. In such a case, a thermal effect of high-intensity ultrasound waves is used in order to shrink a vein wall.
A cavitation phenomenon can also be used. For instance, for the treatment of varicose veins, cavitation bubbles are created in order to generate local shock waves when they collapse. This allows destroying the endothelium of a given vein or vessel. In order to obtain a significant cavitation phenomenon, ultrasonic waves must be generated and focused at the right location. To this end, crossed ultrasonic beams can be used, as mentioned in EP-A-2 636 428.
Spider veins, that are close to the skin of a subject, are sometimes visible or partially visible. It is known to treat a vein at several points along its length in order to increase the efficiency of a treatment. However, when one places a treatment device on the skin of a subject or patient, this device hides the vein, so that the practitioner cannot accurately orientate and/or move the device in order to precisely focus ultrasonic waves on the venin, along its path.
As mentioned in WO-A-2014/160964, one can use an ultrasound imaging probe in order to detect a target within a soft body, this being based on an ultrasound technology. However, such an ultrasonic probe is expensive and hardly detects a vein with a small diameter, where blood flows with a low flow rate. Actually, a vein where blood has a low flow rate is difficult, and sometimes impossible, to detect via Doppler or B-mode ultrasound technology. Actually, the smaller a vein is and the lower the blood flow rate in a vein is, the more difficult and the more costly the detection is.
On the other hand, WO-A-2009/112969 and WO-A-2012/156863 rely on the application of high intensity focused ultrasound (HIFU) with different types of ultrasound sources. They do not allow precisely controlling where the ultrasonic waves are applied.
EP-A-1 795 131 discloses a HIFU system which includes a treatment head with a light source illuminating the skin of a patient. Such a construction does not allow obtaining a clear image of an object located below the skin, such as a vein. Moreover, a single ultrasound transducer is used, which implies that the cavitation zone obtained at its focal point might be unstable. In addition, as visible for instance on FIG. 3 of this document, the light source is radially offset from an imaging unit, which does not allow precise enlightening of an object to be viewed.
WO-A-02/09813 discloses a method and a device for epilation where a single intrinsically focused transducer is used, with the same inconvenients as above with regards to the stability of the cavitation zone. Some lighting means are provided in the form of a low intensity laser, for aiming the ultrasonic beam, and a light source, for illuminating an area to be viewed. These items are not mounted on a body of the device but connected to it via light guides, which is cumbersome. Moreover, the light is directed towards the skin, which is satisfactory for seeing a hair for epilation, but does not allow clearly seeing an object located below the skin, such as a vein. The light coming from the laser or the light source arrives in a central axial zone of the device, in the same zone as the boresight of a video camera. Thus, only direct illumination of the skin is possible.
Similar issues of potential hiding of a zone to be treated occur for the treatment of acne, wrinkles, cellulitis, tattoos, melanoma and lentigines.

Device and system for generating ultrasonic waves in a target region of a soft solid and method for locally treating a tissue


The described embodiments of the present invention include a water filter having a float portion with a magnet that moves up and down due to water flow to activate a switch for tracking the use time of the filter.

Water filters have become increasingly prevalent as consumers have become more health conscious. Typically, these water filters attach directly to the water faucet outlet and filter water as it flows out of the faucet. Generally, these water filters are comprised of filter cartridges that must be replaced after a certain period of time or use.
Accordingly, there have been prior filters designed to detect the amount of flow through the filter and to alert the user when the filter needs to be replaced. For example, U.S. Pat. No. 5,935,426 to Giordano et al. teaches a water filter having a flow detection means. The Giordano patent also describes the use of a red, yellow, green LED configuration to alert the user of the status of the water filter.
The present invention relates to a new and improved water filter for detecting flow through the filter and for alerting the user of the status of the filter.

Water filter having a filter use time indicator


A pipe cutter according to the invention has an inner head part which, in the working position, rotates about a pipe which is clamped in the inner head part and is to be processed. Integrated in the inner head part are a spring-mounted cutting wheel head (8) having a cutting wheel (7) for cutting the pipe and a plurality of support rollers (9) in spring-mounted receptacles (10). The arrangement and formation of cutting wheel (7) and support rollers (9) is such that the clamped pipe is at right angles to the cutting wheel (7), and a right-angled cut is thus achieved. Moreover, a defined feed cutting force can be set by the spring mounting of cutting wheel head (8) and support roller receptacles. During cutting, the pressure on the pipe decreases with increasing cutting depth, and the pipe can thus be cut cleanly and without burrs.

1. Field of the Invention
The invention relates to a pipe cutter, and in particular a hand-held pipe cutter.
2. Description of the Background Art
The parting of pipes—also referred to as "cutting into sections", is often the first step in installation work. The quality of the cutting, i.e. in particular the quality of the cutting edge, is of major importance for subsequent operations, in particular for subsequent joining of cut pipe ends. An important criterion for clean parting—e.g. cutting, sawing or punching—of pipes is a right-angled cut; the pipe must therefore be at right angles to the parting tool, such as a cutting wheel. Furthermore, the stable position of the pipe in the tool and the quality of the tool components, such as of the cutting wheel, and of course the parting process itself play a role with regard to the parting quality.
For the cutting of pipes, pipe cutters have been developed for many years. In particular for use on the building site, hand-held tools are desired. Criteria for these tools are the weight, the convenience and compactness, the cost and of course the cutting quality. Moreover, desired tools are those which can be flexibly used and in particular do not occupy too much space during cutting, since it is often also necessary to cut already laid pipes with little space around the pipe. A clean cut when parting pipes is an absolute necessity, since otherwise damage during subsequent use and processing of the pipes is the result. Poor cut edges result, for example, during the joining of pipes by pressing, in pipe ends tilted in the fittings and damaged sealing rings or deformed press fittings and hence leaking systems.
What is generally problematic in the case of known pipe cutters is the ratio of cutting surface quality to length tolerance to costs. Economical tools which are easy to handle often do not give the required cut quality; thus, for example when the pipe is held slightly skew, skew cut edges are the result; moreover, strong contraction of the pipe toward the inside and deformation of the pipe generally occur during cutting. Another disadvantage is the formation of external and/or internal burrs, which have to be removed after the parting and for this reason commercially available tools often have an integrated deburrer. Neglected burrs can cause turbulence in the pipe interiors, which lead to pressure drops and corrosion damage and moreover constitute a risk of injury for the workman.
If the cutting tool is formed in such a way that the pipe has to be rotated for cutting, the safety of the workman may be in danger by deflection of the pipe during processing in the case of unbalanced positioning.