A magnetoresistive (MR) read transducer and method of fabricating same. A soft magnetic layer and an MR layer extend over a central active region and passive end regions of the transducer. A nonmagnetic spacer layer separates the soft magnetic film layer and MR layer and extends over the central active region and at least part of both passive end regions. An antiferromagnetic layer directly contacts the MR layer only in the end regions and produces an exchange bias field between the antiferromagnetic layer and the MR layer that is oriented at a preselected acute angle to the longitudinal direction of the transducer. This results in the MR layer being oriented at the preselected acute angle and the soft magnetic film layer in the passive end regions being transversely oriented by magnetostatic coupling to the MR layer. To fabricate the transducer, the antiferromagnetic layer is annealed in an external field above the Neel temperature to produce the canted exchange bias field. As a result of the canting, the magnetic moments of the central active region and the passive end regions are matched during a read operation.

An MR read transducer requires an active region and passive regions. The active region comprises suitable means for transversely biasing the transducer, and each passive region generally includes suitable means for longitudinally biasing the transducer.
The longitudinal bias is necessary to free the MR transducer from Barkhausen noise. This longitudinal bias can be provided by a "patterned exchange" which uses either an antiferromagnetic or a hard magnetic biasing layer that is exchange-coupled to the passive regions to induce a single magnetic domain state in the active region.
Commonly assigned U.S. Pat. No. 4,663,685 describes a simple implementation of patterned exchange using a continuous spacer layer. This patent discloses an MR transducer comprising a continuous spacer layer separating a continuous MR layer and a continuous soft magnetic layer. Anti-ferromagnetic bias material deposited only in the passive end regions produces a bias field which is directed longitudinally of the transducer. Because the magnetic orientation of the soft magnetic layer in the passive regions is not controlled by the exchange coupling, multiple magnetic states are possible. Tests of head disk assemblies (HDAs) show occasional problems because the magnetic fields generated by the passive regions influence the MR response of the transducer.
Commonly assigned U.S. Pat. No. 4,785,366 shows a patterned spacer layer configuration that was developed to provide direct control, by exchange coupling, of the entire passive regions to produce optimium transducer performance. This patent discloses an MR transducer comprising a patterned spacer layer between a continuous soft magnetic layer and a continuous MR layer, and an exchange bias layer of antiferromagnetic material overlaying the soft magnetic layer. The spacer layer extends beyond the active region into the adjacent ends of the passive end regions to provide alignment tolerance during fabrication.
It has been found during manufacture and testing at the HDA level, however, that some patterned spacer configured transducers have been unstable as denoted by waveform distortions. It was also found that these transducers often exhibited considerable variability in output characteristics even if processed from the same wafer row. Both the instabilities and some of the performance variations of the patterned spacer configuration were found to originate within the regions of unconstrained moment in the soft magnetic film that correspond to the regions in which the spacer layer extends beyond the central active region into the two passive end regions. No correlation with process variations were found to account for these random occurrences of instability.
Since no process solution appears possible, there is a need for a solution that can be achieved by a configuration change that will increase the tolerable range of normal material and manufacturing process variations in a manner which does not complicate the fabrication process and maintains high yields.
No prior art known to applicants discloses or suggests an MR transducer of either the continuous spacer or the patterned spacer configuration having a canted exchange field in the passive end regions to match the magnetic moment between the central active region and the passive end regions during reading; i.e., during operation when the current is on. In prior arrangements, the orientation of the passive region remained the same whether the current was on or off and the moment was matched when the current was off, rather than when the current was on.

Stabilization of magnetoresistive transducer using canted exchange bias


Provided is a light emitting diode (LED) streetlamp device. The LED streetlamp device includes a body frame comprising a first flat part and a first inclined part formed being extended from a rim portion of the first flat part with a certain incline angle θ1, a light emitting part installed on the first flat part and the first inclined part, comprising a plurality of LED lamps, and a transmission plate comprising a second flat part located being separated from the first flat part with a certain distance and a second inclined part extended from a rim portion of the second flat part with a certain incline angle θ2 separated from the first inclined part with a certain distance and covering the body frame.

Generally, streetlamp devices are lighting fixtures installed along the street to provide safety and security in road traffic. Such streetlamp devices are installed on main roads, roads in business zones and residential zones in suitable forms depending on places thereof. According to the present installation standards of streetlamp devices, when installing streetlamp devices 10 meters above the ground, side illumination occurring in locations 12 meters from right and left sides of a place on the ground, where the streetlamp device is installed, should be 20 lux.
Conventional streetlamp devices employ lamps emitting light using the resistance of filaments, which have short lifespans and consume a lot of power. Recently, there have been developed and applied light emitting diode streetlamp devices employing LED lamps as light sources, the LED lamps having lifespans longer than those of the lamps employing filaments, the efficiency of the LED lamps being high.
On the other hand, as shown in FIG. 1, a general LED streetlamp device 100 includes a body frame 130 with LED lamps 110 attached as light sources and a reflective plate 120 reflecting light from the LED lamps 110 toward an area directly below or a peripheral area; and a transmission plate 140 manufactured using transparent glass or transparent plastic covering the LED lamps 110 and the reflective plate 120 attached to the body frame 130. Also, on top of the body frame 130, there is provided a fastening portion 150 formed in the shape of a bar or a pipe. Accordingly, the LED streetlamp device 100 may be attached and installed to a connecting bar 210 of a lamppost 200 by coupling the fastening portion 150 therewith using a general coupling member 220 formed of one of a bolt, a nut, and a bracket.
Also, the connecting bar 210 of the lamppost 200, coupled with the fastening portion 150, is formed in the shape of a bar with a certain diameter. However, in some cases, as an example, when providing a shielding member 230 for protecting the streetlamp device 100 together with the connecting bar 210 formed in a single body, as shown in FIG. 2, the connecting bar 210 may have an extended diameter of an end thereof. In this case, the fastening portion 150 of the LED streetlamp device 100 is also designed according to the extended diameter of the connecting bar 210.
Referring to FIG. 2, a reference numeral 210a indicates an extended diameter portion of the connecting bar 210 and a reference numeral 150a indicates an extended diameter portion of the fastening portion 150. Also, in FIG. 2, for example, the extended diameter portion 150a of the fastening portion 150 is coupled with the extended diameter portion 210a of the connecting bar 210 by a screw-connection.
However, considering that streetlamp devices are generally deployed with intervals about 30 to 50 meters apart along the street, the LED streetlamp devices 100 should emit light to the front and rear of the street to provide 20 lux of illumination on a spot on the ground 12 meters from the front and rear of a location on the street, which is the standard for installing streetlamp devices.
However, since the LED streetlamp device 100 only has one of a flat configuration and a configuration inclined toward a certain direction and emits light only toward the area directly below and a certain position of the peripheral area, it is not possible to uniformly emit light toward the area directly below and the peripheral area.
Also, since the LED streetlamp device 100 emits heat of a high temperature due to characteristics thereof, there may occur damage to diodes due to the heat. However, there is no effective countermeasure against the heat emission of the body frame 130.
Also, there is a problem in that it is not easy to install the lamp on the lamppost. That is, it is necessary to prepare streetlamp devices having diameter portions suitable for the diameter of the connecting bar.
Also, in case of the streetlamp device 100, since the light from the light sources 110 passes through the transmission plate 140, the strength thereof is decreased due to reflection or scattering.


In the process of refilling a consumed inkjet printer cartridge, the nozzle and the internal ink carrier medium are cleaned by applying steam under pressure in short burst intervals at the nozzle. The dissolved ink remnant in the cartridge is extracted by a suction device applied over the nozzle. The completely cleaned cartridge is refilled by injecting fresh ink through a refill opening formed in the cartridge casing at a location directly opposite to the nozzle.

1. Field of the Invention
This invention relates to a process and system for refilling printer ink cartridges.
2. Background Art
Inkjet printers have gained popularity among computer users in view of their low initial cost and versatility. They also produce letter and graphic prints with high quality. The ink required by printing is provided by ink cartridges mounted to the print head of the printer. Ink is held in a carrier material such as foam fiber located within a cartridge, which is saturated with the ink. The printer extracts the ink from the cartridge by vacuum pressure and delivers it to the print head. Inkjet printers consume printing ink at a fast rate particularly when printing graphics and photographic pictures. As an ink cartridge only holds a limited amount of ink, the cartridges would require replacing frequently. Therefore, the cost of operating an inkjet printer is high with the necessity of having to replace the ink cartridges frequently. Furthermore, the spent cartridges are discarded in the garbage which contributes to the contamination of the natural environment. In order to alleviate the above problems, the users of inkjet printers seek to refill the consumed cartridges rather than replacing them with new cartridges so as to reduce the operating cost as well as the unnecessary discarding of the used cartridges. However, when the printer can no longer extract ink from an ink cartridge, there is actually still a trace of ink remaining within the cartridge. Such small amount of ink remnant would quickly become dry up to blockage at the cartridge nozzle and hardening of the carrier material particularly adjacent to the nozzle. When fresh ink is injected into the cartridge for refilling it under such condition, the harden carrier material would loose the required physical characteristic for holding the ink and delivering it to the print head under vacuum. Furthermore, the dry up remnant of ink at the nozzle also form blockage to impede the flow of ink out of the cartridge.
For the above reason, it has been problematic in the refilling of ink cartridges in that the nozzle of the cartridge without resolving the above problems. The blockage at the nozzle may be removed by cleaning the nozzle external surface with water if the cartridge is to be refilled as soon as the ink has been consumed. However, cleaning the nozzle externally often does not eliminate the blockage within the opening of the nozzle particularly when the cartridge has been removed from the printer for some time without refill it immediately. Also, it does not eliminate the hardening of the carrier material in the cartridge. Thus, the refilled cartridge either does not function or will only function inefficiently. Furthermore, the wiping operation would often destroy the physical structure of the nozzle.
Attempts have been made to remove the internal ink remnant from the cartridge by injecting hot water into the cartridge through the nozzle. However, since the openings of the nozzle of the cartridge are very small, such process is rather messy and unsatisfactory as very little amount of hot water would penetrate into the cartridge.

Consumed ink cartridge refilling process


Embodiments of the present invention address deficiencies of the art in respect to presence awareness for instant messaging and provide a novel and non-obvious method, system and computer program product for adaptive instant messaging awareness. In an embodiment of the invention, a method for adaptive instant messaging awareness can be provided. The method can include receiving an instant message for transmission to a user of an instant messaging system and determining that the user is not currently available to receive an instant message. The method can further include delaying transmission of the instant message to the user until a later determination that the user is available to receive an instant message.

1. Field of the Invention
The present invention relates to the field of instant messaging and more particularly to presence awareness for instant messaging.
2. Description of the Related Art
Electronic mail, referred to in the art as e-mail, has proven to be the most widely used computing application globally. Though e-mail has been a commercial staple for several decades, due to the explosive popularity and global connectivity of the Internet, e-mail has become the preferred mode of asynchronous communications, regardless of the geographic separation of communicating parties. Today, more e-mails are processed in a single hour than phone calls. Clearly, e-mail as an asynchronous mode of communications has been postured to replace all other modes of communications excepting voice telephony.
In contrast to the asynchronous nature of e-mail, the recent rapid development of the Internet has led to advanced modes of synchronous, real-time collaboration able to fulfill the real-time communicative requirements of the modern computing participant. Using the Internet as a backbone, individuals worldwide can converge in real-time in cyberspace to share ideas, documents and images in a manner not previously possible through conventional telephony and video conferencing. To facilitate collaboration over the Internet, a substantial collection of synchronous messaging technologies and protocols have been assembled to effectively deliver audio, video and data over the single data communications medium of the Internet. These synchronous messaging technologies include several, real-time human-to-human collaborative environments such as instant messaging and persistent chat rooms.
In the conventional instant messaging and chat environment, different collaborators can engage in a real-time exchange of messages including text messages, graphical information and even audiovisual information in a common messaging space. The common messaging space can accommodate a pair of conversants to a chat, or multiple conversants to a conference. In some circumstances, the initiation of the chat can be spontaneous upon one conversant recognizing the presence and availability of a partner conversant. In other circumstances, the initiation of the chat can be planned and can even subsist in a calendared event in a calendaring and scheduling system.
Conventional instant messengers rely upon presence awareness in assisting users with the establishment of a chat session with other users. Presence awareness refers to the ability of the instant messaging system to determine when a user is available to engage in a chat session. Generally, presence awareness can be manually established by each user through a selection of a number of states ranging from "I am available" to "Away from computer" to "Do Not Disturb". Alternatively, presence awareness can be established automatically by sensing activity in a computer. Idleness past a threshold duration of time can be indicative to the absence of a user and the state of the user can be set by the presence awareness logic of the instant messaging system accordingly.
Situations oftentimes arise where one individual intends to contact another individual through instant messaging, but cannot establish contact as the other individual is not sitting at his computer. This can be particularly frustrating if individuals are geographically separated—where it is not possible to physically locate the other individual in person. In situations like these, the initiating individual may wait to type and send the instant message until the other conversant is available for instant messaging. If enough time goes by or the initiating individual becomes distracted, he may forget to send the instant message at a later time. Even if he later remembers he had a message to send, the initiating individual may take a while to remember the subject matter of the instant message he intended to send. This can be annoying and time-consuming for the user. The inability to immediately contact the desired conversant in such circumstances can injure productivity through failed or canceled communications and lost time in recalling earlier intended communications.

Transmission of instant messages according to availability

International Business Machines Corporation


Provided are novel prodrugs of esuberaprost and pharmaceutical compositions thereof, as well as methods of making and methods of using these prodrugs.

Prostacyclin derivatives are useful pharmaceutical compounds possessing activities such as platelet aggregation inhibition, gastric secretion reduction, lesion inhibition, and bronchodilation Beraprost is a synthetic benzoprostacyclin analogue of natural prostacyclin that is currently under clinical trials for the treatment of pulmonary hypertension and vascular disease (excluding renal disease) in North America and Europe. Esuberaprost is a reformulated single isomer of beraprost currently being developed for the treatment of pulmonary arterial hypertension and vascular disease.
Beraprost and related benzoprostacyclin analogues are disclosed in U.S. Pat. No. 5,202,447 and Tetrahedron Lett. 31, 4493 (1990). Furthermore, as described in U.S. Pat. No. 7,345,181, several synthetic methods are known to produce benzoprostacyclin analogues, including the pharmacologically active isomer of beraprost, such as beraprost 314-d (esuberaprost).
Derivatives and prodrugs of existing drugs have the ability to improve the physicochemical properties of such drugs. Therefore, it is desired to prepare improved esuberaprost compounds, such as prodrugs, and develop efficient, commercially applicable synthetic methods to the prodrugs of esuberaprost.


A CT system in an example comprises an x-ray source, a detector, a data acquisition system (DAS), and a computer. The x-ray source emits a beam of x-rays toward an object to be imaged. The detector receives x-rays emitted by the x-ray source. The DAS is operably connected to the detector. The computer is operably connected to the DAS. The computer is programmed to reconstruct a CT image of the object to comprise a plurality of CT images, of a respective plurality of points of the object, through employment of a function that describes how many times a trajectory curve, of an interpretation of relative movement between the x-ray source and the object as that of the x-ray source, goes around each of the plurality of points of the object.

The present invention relates generally to diagnostic imaging and, more particularly, to image reconstruction.
Typically, in computed tomography (CT) imaging systems, an x-ray source emits a fan-shaped beam toward a subject or object, such as a patient or a piece of luggage. Hereinafter, the terms "subject" and "object" shall include anything capable of being imaged. The beam, after being attenuated by the subject, impinges upon an array of radiation detectors. The intensity of the attenuated beam radiation received at the detector array is typically dependent upon the attenuation of the x-ray beam by the subject. Each detector element of the detector array produces a separate electrical signal indicative of the attenuated beam received by each detector element. The electrical signals are transmitted to a data processing system for analysis which ultimately produces an image.
Generally, the x-ray source and the detector array are rotated about the gantry opening within an imaging plane and around the subject. X-ray sources typically include x-ray tubes, which emit the x-ray beam at a focal point. X-ray detectors typically include a collimator for collimating x-ray beams received at the detector, a scintillator for converting x-rays to light energy adjacent the collimator, and photodiodes for receiving the light energy from the adjacent scintillator and producing electrical signals therefrom.
Typically, each scintillator of a scintillator array converts x-rays to light energy. Each scintillator discharges light energy to a photodiode adjacent thereto. Each photodiode detects the light energy and generates a corresponding electrical signal. The outputs of the photodiodes are then transmitted to the data processing system for image reconstruction.
To acquire CT images, generally, one of two projection geometries is used; either a parallel beam geometry or a fan beam geometry. With parallel beam geometry, all x-rays in a projection are parallel to one another. With fan beam geometry, the x-rays at a given projection angle diverge resulting in a fan-like appearance. Most modern CT scanners use fan beam geometry in the acquisition and reconstruction of CT images. Notwithstanding the advantages of fan beam geometry relative to parallel beam geometry, some constraints are placed thereon.
Specifically, fan beam reconstruction was first studied and modeled in the circular scanning case, and later extended to the case of non-circular scanning loci with some constraints. In this regard, conventional fan beam reconstructions are generally based on the Radon formula or the parallel beam reconstruction formula, and completed via the coordinate transformation from parallel beam to fan beam geometry. As a result, conventional fan beam reconstruction techniques are not well-suited for acquiring data from non-still objects, such as during head scans.
For example, a patient having a head CT may be unable to hold the head still and steady during the CT scanning. The movement of the head may result from the patient being young, old, severely injured, or other reasons. Head motion of the patient occurs more often in head perfusion CT. In this technique to measure cerebral blood flow, the same slice of the head is continuously scanned and circumscribed. A specified slice of the brain may be scanned for forty to fifty seconds continuously. A contrast material is injected and the rise and fall of the contrast is monitored within the blood vessels and all the other surrounding tissue. A perfusion map is built to measure several key physiological parameters for the brain such as the mean transit time and blood volume. Since the head is supposed to be an object fixed in space, any movement during data acquisition can negatively affect the CT images acquired therefrom.
Therefore, it would be desirable to design an apparatus and method that enables CT imaging for moving objects with a circular source locus, and CT imaging for a still object with a complicated source locus.

CT image reconstruction through employment of function that describes interpreted movement of source around particular point of object


Instantly dissolving buccal films comprising certain pH modifiers, film formers, film modifiers, and solubilizing agents are provided. Methods of providing the buccal film to enhance the dissolution and bioavailability of low solubility basic drugs, such as dapoxetine hydrochloride, in a subject are also provided.

Intraoral delivery systems (IODSs) have been used as a promising strategy to surmount the problems associated with oral drug administration. These dosage forms offer the advantages of easy administration and rapid action as they disintegrate or dissolve rapidly in the mouth. In addition, direct absorption of drugs into the systemic circulation could be achieved via the buccal mucosa, thus bypassing hepatic first pass [1]. Instantly disintegrating or dissolving tablets (IDT) have been introduced as the first IODSs for patients who suffer from dysphagia. They are characterized by their rapid disintegration and/or dissolution; however, they have some drawbacks such as difficult handling owing to their fragility. Accordingly, instantly dissolving buccal films have been introduced recently as an alternative to surpass the limitations associated with instantly dissolving tablets [2-4].
Instantly dissolving buccal films (IDBFs) are hydrocolloid based films that readily dissolve upon contact with the salivary fluid. They have recently gained attention due to enhanced patient compliance and capability of surmounting the problem of hepatic first pass of many drugs [5,6]. However, intraoral administration of poorly soluble drugs poses a great challenge for their buccal absorption. Several approaches have been utilized for enhancing the dissolution of drugs including solid dispersion with water soluble polymers, binary systems with cyclodextrins [7], use of surfactants [8] and pH modifiers [9].
Dapoxetine hydrochloride (DPX) is a selective serotonin reuptake inhibitor for depression treatment. It was recently approved as an oral treatment for premature ejaculation (PE) to be the first selective serotonin reuptake inhibitor approved for this function [22,23], however, DPX has an oral bioavailability of 42% owing to its significant hepatic first pass metabolism [24]. DPX presystemic metabolism represents a challenging limitation for oral administration of the drug and foreshadows the potential of utilizing transmucosal route for enhancing the drug's bioavailability [25]. However, DPX is a weakly basic drug with a pH dependent solubility that could limit its dissolution in the body's neutral fluids and subsequent absorption via mucosal barriers [26].
Transmucosal delivery of DPX via sublingual and intranasal mucosa has been investigated by Fouad et al. [26,27] who developed DPX loaded instantly-soluble matrix and instantly-dispersible nanocarrier powder systems. In addition, buccal delivery of DPX has been investigated by Liew and Peh [28] who developed DPX orally disintegrating tablets and El-Refai et al. [29] who developed vardenafil hydrochloride/DPX hydrochloride orodispersible tablets. However, no attempts were reported for the formulation of dissolvable buccal films of DPX.
Due to the bioavailability problems with delivery of basic drugs, alternative and effective drug delivery systems are needed.


A magnetization direction control method for controlling magnetization directions of first to third ferromagnetic layers (11-13) within a synthetic antiferromagnet structure (10A) having the first to the third ferromagnetic layers (11-13) and first and second non-magnetic layers (21, 22) interposed therebetween, without coupling antiferromagnetic material. The magnetization direction control method is composed of steps of (a) applying an external magnetic field HE to the synthetic antiferromagnet structure (10A) so as to direct the magnetizations of the first to third ferromagnetic layers in the same direction, and (b) reducing the external magnetic field to reverse the magnetization of one or some of the first to third ferromagnetic layers (11-13). The synthetic antiferromagnet structure (10A) is configured so that the magnetization of the first ferromagnetic layer (11) is reversed more easily than magnetizations of the other ferromagnetic layers in a state in which the magnetizations of the first to third ferromagnetic layers (11-13) are directed in the same direction.

A synthetic antiferromagnet structure designates a structure composed of a plurality of ferromagnetic layers and an intermediate non-magnetic layer(s) interposed therebetween. The synthetic antiferromagnet structure is configured so as to antiferromagnetically couple the adjacent ferromagnetic layers. More specifically, each intermediate non-magnetic layer is formed of material with a film thickness so that the adjacent ferromagnetic layers are antiferromagnetically coupled. It is well-known to those skilled in the art of the MRAM that the adjacent ferromagnetic layers can be antiferromagnetically coupled by appropriately determining material and the film thickness of the intermediate non-magnetic layer.
For example, as disclosed in published Japanese translations of PCT international publication No. 2003-536267, the synthetic antiferromagnet structure is often used as a fixed layer (pinned layer) of the MRAM memory cell. One advantage of using the synthetic antiferromagnet structure as a fixed layer of the MRAM memory cell is to decrease an undesired bias magnetic field applied to a free layer of the MRAM memory cell. This results from the fact that the synthetic antiferromagnet structure allows decreasing a total magnetic moment down to ideally zero. Since a magnetic field generated by the synthetic antiferromagnet structure is proportional to the magnitude of the magnetic moment, a magnetic field applied to a free layer from a fixed layer can be decreased by using a synthetic antiferromagnet structure as the fixed ferromagnetic layer.
In recent years, a technique has been studied which uses synthetic antiferromagnet structures as the free layer of the MRAM memory cell. U.S. Pat. No. 6,545,906 discloses a technique for improving the selectivity of memory cells and data retention properties, and further to suppress the shape dependency of a coercive field by applying the synthetic antiferromagnet structure to the free layer.
In order to employ the synthetic antiferromagnet structure in the MRAM memory cell, there is required a technique to direct magnetizations of ferromagnetic layers within the synthetic antiferromagnet structure to desired directions. The fixed layer is required to have magnetizations of the synthetic antiferromagnet structure directed to desired directions in the MRAM manufacturing process. The free layer, on the other hand, is required to have magnetizations of the synthetic antiferromagnet structure directed to a direction corresponding to data to be written to the MRAM memory cell.
When the synthetic antiferromagnet structure is used as the fixed layer, the magnetization directions of ferromagnetic layers within the synthetic antiferromagnet structure are most typically controlled by using an antiferromagnetic layer. FIG. 1 is a cross-sectional view showing a typical structure of the MRAM memory cell in which the synthetic antiferromagnet structure is used as the fixed layer. An MRAM memory cell 1000 includes a fixed layer 1100, a free layer 1200, and a tunnel barrier layer 1300 interposed therebetween. The fixed layer 1100 is formed of a synthetic antiferromagnet structure. More specifically, the fixed layer 1100 is composed of ferromagnetic layers 1101 to 1103 and non-magnetic layers 1111 and 1112 interposed therebetween. The fixed layer 1100 is connected to an antiferromagnetic layer 1400, thereby magnetizations of the ferromagnetic layers 1101 to 1103 are fixed.
The magnetization directions of the ferromagnetic layers 1101 to 1103 are controlled by annealing while applying a strong external magnetic field. Specifically, a strong magnetic field is applied to the MRAM memory cell 1000 so as to align the magnetizations of the ferromagnetic layers 1101 to 1103 in the same direction. When the external magnetic field has been removed, the magnetization of one of the ferromagnetic layers 1101 to 1103 is reversed, thereby the magnetizations of the ferromagnetic layers 1101 to 1103 are rearranged to directions so that the synthetic antiferromagnet structure is stabilized in terms of energy. In this rearrangement, the magnetization of the ferromagnetic layer 1103 is not reversed because a magnetization reversal thereof is prevented by an exchange interaction from the antiferromagnetic layer 1400; the magnetization of the ferromagnetic layer 1103 is fixed to the direction of the external magnetic field. Accordingly, in order to stabilize the synthetic antiferromagnet structure in terms of energy, the magnetization of the ferromagnetic layer 1102 is reversed to the direction opposite to the external magnetic field, and the magnetization of the ferromagnetic layer 1101 is directed to the same direction with the external magnetic field without being reversed. This implies that the magnetizations of the ferromagnetic layers 1101 to 1103 are directed to the desired directions by applying the external magnetic field to a direction to which the magnetizations of the ferromagnetic layers 1101 and 1103 are to be directed.
In the magnetization direction control mentioned above, the antiferromagnetic layer 1400 is coupled to the synthetic antiferromagnet structure so as to fix final magnetization directions of the ferromagnetic layers 1101 to 1103. The antiferromagnetic layer 1400 plays an important role in controlling the magnetization directions.
On the other hand, U.S. Pat. No. 6,545,906 discloses a method for reversing magnetization directions of ferromagnetic layers within the synthetic antiferromagnet structure to the desired directions when the synthetic antiferromagnet structure is used as the free layer, which is specifically a method for writing data to the synthetic antiferromagnet structure. This U.S. Pat. No. 6,545, 906 discloses two methods for writing data to the synthetic antiferromagnet structure: the toggle writing method and the direct writing method.
FIG. 2 is a cross sectional view showing a structure of an MRAM memory array disclosed in U.S. Pat. No. 6,545,906, and FIG. 3 is a plane view showing a structure of the above MRAM memory array. As shown in FIG. 2, the MRAM memory array includes a word line 2400, a bit line 2500, and a memory cell 2000 interposed therebetween. The memory cell 2000 is composed of a fixed layer 2100, a free layer 2200, and a tunnel barrier layer 2300 interposed therebetween. The fixed layer 2100 and the free layer 2200 are both composed of the synthetic antiferromagnet structure. The fixed layer 2100 includes ferromagnetic layers 2101 and 2102, and a non-magnetic layer 2103 interposed therebetween, while the free layer 2200 includes ferromagnetic layers 2201 and 2202, and a non-magnetic layer 2203 interposed therebetween.
As shown in FIG. 3, easy axes of the ferromagnetic layers 2201 and 2202 are directed at an angle of 45 degrees to both the word line 2400 and the bit line 2500. A magnetization M1, of the ferromagnetic layer 2201 and a magnetization M2 of the ferromagnetic layer 2202 are antiparallelly directed each other along the direction of the easy axes.
FIGS. 4 and 5 show a procedure of the toggle writing method disclosed in U.S. Pat. No. 6,545,906. Referring to FIG. 5, it should be noted that an x-y coordinate system is introduced below for convenience of explanation. In the x-y coordinate system, the direction of the x-axis is defined as being parallel to the word line 2400, and the direction of the y-axis is defined as being parallel to the bit line 2500.
In the toggle writing method, as shown in FIG. 4, a current IWL is applied to the word line 2400 in the +x direction at the time t1. As shown in FIG. 5, the application of the current IWL generates a magnetic field HWL in the +y direction, and the magnetic field HWL causes the magnetization M1 of the ferromagnetic layer 2201 and the magnetization M2 of the ferromagnetic layer 2202 to be slightly rotated in the +y direction. The rotation angle of the magnetizations M1 and M2 is an angle in which a resultant magnetization MR thereof is in parallel with the +y direction.
Subsequently, a current IBL is applied to the bit line 2500 in the +x direction at a time t2. The application of the current IBL generates a resultant magnetic field HWL+HBL at an angle of 45 degrees to both the x-axis and the y-axis. This resultant magnetic field HWL+HBL causes the magnetizations M1 and M2 to be rotated clockwise so that the resultant magnetization MR is directed in parallel to the resultant magnetic field HWL+HBL.
This is followed by shutting off the current IWL applied to the word line 2400 at the time t3. The shutoff of the current IWL causes only the magnetic field HBL to be applied to the ferromagnetic layers 2201 and 2202 in the +x direction. This magnetic field HBL causes the magnetizations M1 and M2 to be further rotated clockwise so that the resultant magnetization MR is directed in parallel to the magnetic field HBL.
Finally, the current IBL applied to the bit line 2500 is shut off at the time t4. The shutoff of the current IBL results in that the magnetic fields stop being applied to the magnetizations M1 and M2, and the magnetizations M1 and M2 are redirected along the closest easy axis. As a result, the magnetization M1 and M2 are reversed to the direction opposite to the original direction.
One feature of the toggle writing method is that the magnetizations M1 and M2 are reversed every time the toggle writing is performed, regardless of the original directions of the magnetizations M1 and M2.
On the other hand, the direct writing method is a method in which it depends on the original direction of the magnetizations M1 and M2 whether or not the magnetizations M1 and M2 are reversed, as shown in FIGS. 6 and 7. The direct writing method controls the reversal of the magnetizations M1 and M2 by using the resultant magnetization MR that initially exists in the synthetic antiferromagnet structure due to the unbalance of the magnetizations M1 and M2. More specifically, as shown in FIG. 6, the application of the magnetic field HWL causes the magnetizations M1 and M2 to be largely rotated clockwise, if the direction of the magnetic field HWL generated by the application of the current IWL forms an obtuse angle to the direction of the resultant magnetic field MR with no magnetic field applied. In this case, the magnetizations M1 and M2 to be reversed when the magnetic field HBL is then applied. On the other hand, as shown in FIG. 7, the magnetizations M1 and M2 is not reversed, if the direction of the magnetic field HWL forms an acute angle to the direction of the resultant magnetization MR with no magnetic field applied. It should be noted that the initial existence of the resultant magnetization MR is important in the direct writing method.
There is room for improvement in the above-mentioned prior arts in the following points. The technique to control magnetizations of ferromagnetic layers in the synthetic antiferromagnet structure using the antiferromagnetic layer suffers from a problem of the diffusion of materials of the antiferromagnetic layer. Anti-ferromagnetic material used in the MRAM generally includes manganese (Mn); however, manganese within the antiferromagnetic material diffuses in a heat treatment at a high temperature. The diffusion of manganese undesirably causes deterioration of the characteristics of the MRAM memory cell.
The toggle writing method disclosed in U.S. Pat. No. 6,545,906, on the other hand, suffers from a drawback that a read operation is required before performing a write operation. The toggle writing results in reversal of the magnetizations of the ferromagnetic layers within the synthetic antiferromagnet structure, regardless of the original states. Accordingly, in order to direct the magnetizations toward the desired directions, magnetization directions of the ferromagnetic layers of the synthetic antiferromagnet structure are determined before writing data to the synthetic antiferromagnet structure, which implies the read operation needs to be executed. Therefore, the toggle writing operation is essentially unsuitable for controlling the magnetizations of the ferromagnetic layers of the synthetic antiferromagnet structure used as the fixed layer. When the synthetic antiferromagnet structure is used as a free layer, the fact that the read operation needs to be executed before a write operation is not preferable, because the write cycle time is increased.
In addition, the direct writing method disclosed in U.S. Pat. No. 6,545,906 suffers from a drawback that the magnetizations of the synthetic antiferromagnet structure are not essentially balanced, that is, the initial existence of the resultant magnetization is required. The existence of the resultant magnetization implies that the synthetic antiferromagnet structure has a magnetic moment and the synthetic antiferromagnet structure generates the magnetic field accordingly. This causes magnetic interference to be generated between adjacent MRAM memory cells. This is not preferable because the advantages of the synthetic antiferromagnet structure are reduced in a sense.
Japanese Laid Open Patent Applications Nos. 2003-8100 and 2003-309305 disclose other techniques to utilize the synthetic antiferromagnet structure as the free layer. However, these techniques are aimed to improve a reproduced output of a magnetic head. These documents do not refer to anything about an MRAM data writing or a magnetization direction control of the fixed layer.
In addition, Japanese Laid Open Patent Application No. 2003-16624 discloses a magnetic recording medium including a synthetic antiferromagnet structure. However, this document does not disclose anything about the MRAM data writing or the magnetization direction control of the fixed layer.
From the background as described above, there is a need for providing a new technique for the control of the magnetization direction of ferromagnetic material within a synthetic antiferromagnet structure.

Magnetization direction control method and application thereof to MRAM


A method and network that employs N attendant, messaging and content-based speech systems networked together to transfer call sessions via a VoIP bi-directional link. To enhance network performance, each of the N systems of the network includes an extension database having N city or system directories identifying the extensions and the names associated with such extensions. The caller is given a prompt to provide the network a city where the target resides. Thereafter, the network determines the target's extension by directly accessing the appropriate directory.

Systems that network voicemail systems to facilitate a distributed office, include, without limitation, networks by Cisco®, Advanced Voice®, etc. Networks like that of Cisco® have included voice over Internet protocol (VoIP) communications. However, prior networked voicemail systems do not transfer the session of the caller from one system to another system of the network using speech VoIP to transfer the session. Instead, prior systems transfer messages or calls but not the entire session. Accordingly, since the entire session is not transferred, the caller typically cannot speak to several people at the distant location, leave messages for several people at the location, broadcast messages at the location, etc. all as though they were at the other location.
In view of the above, there is a continuing need for a network of attendant, messaging and content-based speech systems to facilitate a distributed office wherein each system can transfer a session of a caller to another system at a distant location so that the caller can speak to several people at the distant location, leave messages for several people at the location, broadcast messages at the location, etc. all as though they were at the other location.
Additionally, there is a continuing need for a network of self-synchronizing attendant, messaging and content-based speech systems that automatically updates other systems in the network with extension database additions, deletions or other changes.
As will be seen more fully below, the present invention is substantially different in structure, methodology and approach from that of the prior e-trading systems and methods.

System for networking attendant and messaging speech systems

Applied Voice and Speech Technologies, Inc.


Methods of forming a p-channel MOS device in silicon carbide include forming an n-type well in a silicon carbide layer, and implanting p-type dopant ions to form a p-type region in the n-type well at a surface of the silicon carbide layer and at least partially defining a channel region in the n-type well adjacent the p-type region. A threshold adjustment region is formed in the channel region. The implanted ions are annealed in an inert atmosphere at a temperature greater than 1650° C. A gate oxide layer is formed on the channel region, and a gate is formed on the gate oxide layer. A silicon carbide-based transistor includes a silicon carbide layer, an n-type well in the silicon carbide layer, and a p-type region in the n-type well at a surface of the silicon carbide layer and at least partially defining a channel region in the n-type well adjacent the p-type region. A threshold adjustment region is in the channel region and includes p-type dopants at a dopant concentration of about 1×1016 cm−3 to about 5×1018 cm−3. The transistor further includes a gate oxide layer on the channel region, and a gate on the gate oxide layer. The transistor may exhibit a hole mobility in the channel region in excess of 5 cm2/V-s at a gate voltage of −25V.

Power semiconductor devices are widely used to carry large currents and support high voltages. Modern power devices are generally fabricated from monocrystalline silicon semiconductor material. One widely used power device is the power Metal Oxide Semiconductor Field Effect Transistor (MOSFET). In a power MOSFET, a control signal is supplied to a gate electrode that is separated from the semiconductor surface by an intervening insulator, which may be, but is not limited to, silicon dioxide. Current conduction occurs via transport of majority carriers, without the presence of minority carrier injection that is used in bipolar transistor operation. Power MOSFETs can provide an excellent safe operating area, and can be paralleled in a unit cell structure.
As is well known to those having skill in the art, power MOSFETs may include a lateral structure or a vertical structure. In a lateral structure, the drain, gate and source terminals are on the same surface of a substrate. In contrast, in a vertical structure, the source and drain are on opposite surfaces of the substrate.
One widely used silicon power MOSFET is the double diffused MOSFET (DMOSFET) which is fabricated using a double-diffusion process. In these devices, a p-base region and an n+ source region are diffused through a common opening in a mask. The p-base region is driven in deeper than the n+ source. The difference in the lateral diffusion between the p-base and n+ source regions forms a surface channel region.
Recent development efforts in power devices have also included investigation of the use of silicon carbide (SiC) devices for power devices. Silicon carbide (SiC) has a combination of electrical and physical properties that make it attractive for a semiconductor material for high temperature, high voltage, high frequency and high power electronic devices. These properties include a 3.0 eV bandgap, a 4 MV/cm electric field breakdown, a 4.9 W/cm-K thermal conductivity, and a 2.0×107 cm/s electron drift velocity.
Consequently, these properties may allow silicon carbide power devices to operate at higher temperatures, higher power levels and/or with lower specific on-resistance than conventional silicon-based power devices. A theoretical analysis of the superiority of silicon carbide devices over silicon devices is found in a publication by Bhatnagar et al. entitled "Comparison of 6H—SiC, 3C—SiC and Si for Power Devices", IEEE Transactions on Electron Devices, Vol. 40, 1993, pp. 645-655. A power MOSFET fabricated in silicon carbide is described in U.S. Pat. No. 5,506,421 to Palmour entitled "Power MOSFET in Silicon Carbide" and assigned to the assignee of the present invention.
In order to implement a p-channel metal-oxide-semiconductor (MOS) type device, such as an PMOS transistor or a p-channel insulated gate bipolar transistor (P-IGBT) in silicon carbide, it is desirable to provide a high quality MOS channel that is suitable for hole conduction. Typical p-channel MOS devices in silicon carbide have demonstrated unacceptably low hole mobility. It is estimated that a mobility of at least 5 cm2/V-s may be desirable in order for the performance of a P-IGBT to match that of a conventional DMOSFET device having a 10 kV blocking voltage.

Silicon carbide switching devices including P-type channels


Between a movable core chamber and a fuel supply passage, a needle guide slidably supports a needle fixed to a movable core. The needle guide has a communication hole which fluidly connects the movable core chamber and the fuel supply passage. An opening sectional area of the communication hole is defined in such a manner that a fuel discharged amount decreases as an energization start time of a coil is delayed. In a suction stroke, it is restricted that the movable core and the needle bounce toward the fixed core after the needle biases a suction valve toward a stopper by means of a biasing force of a second spring. A relationship between the energization start time of the coil and the fuel discharged amount is properly maintained, so that the fuel discharged amount of the high-pressure pump can be controlled correctly.

A fuel supply system which supplies fuel to an engine is equipped with a high-pressure pump which pressurizes the fuel suctioned from a fuel tank. A high-pressure pump has a plunger which pressurizes the fuel introduced into a pump chamber through a fuel inlet and a fuel supply passage. The pressurized fuel is discharged through a fuel outlet.
JP-2001-304068A shows a high-pressure pump having a needle valve fixed to a movable core. The needle valve sits on or moves apart from a valve seat to close or open the fuel supply passage. The needle valve is supported by a needle guide which is arranged between a movable core chamber and the fuel supply passage. The needle guide has a communication hole which fluidly connects the movable core chamber and the fuel supply passage. Thereby, a movable core chamber functions as a damper chamber, so that a noise due to a collision between the needle valve and the valve seat can be reduced.
In the above high-pressure pump, as an opening sectional area of the communication hole is made larger, a flow resistance of the fuel flowing through the communication hole becomes smaller and the operation and a movement of the movable core become quicker.
Thus, in a suction stroke of the high-pressure pump, after the movable core and the needle valve collide with a stopper by a biasing force of a spring, it is likely that the movable core and the needle valve may bounce toward a fixed core. At this moment, when the movable core and the needle valve are magnetically attracted to the fixed core in a metering stroke, a valve-close time of the needle valve is made earlier, so that a discharging stroke starts earlier than an intended time. Even if an energization start time of a coil is made later, the fuel discharge quantity is increased. It may be difficult to control the fuel discharge quantity with high accuracy.

This patent is subject to a terminal disclaimer.


A paging message processing method is capable of handling paging message processing delay in handover from a Wideband Code Division Multiple Access (WCDMA) network to a Long Term Evolution (LTE) network. A Mobile Switching Center (MSC) includes determines, when an inbound call occurs, whether a Mobility Management Entity (MME) system exists; transmits, when no MME exists, a paging message over an IU interface; determines, when no response message is received, whether a location registration request is received form the MME; transmits, when the location registration request is received, a location registration response to the MME system to deliver the paging message via the MME system; and processes, when a paging response is received, the inbound call. In a heterogeneous network handover from a WCDMA network to an LTE network, the MSC hands over the paging procedure control to the MME immediately so as to facilitate processing the inbound call.

FIG. 1 illustrates an architecture of a mobile communication system.
Referring to FIG. 1, an LTE User Equipment (UE) 105 is located in an area where the Mobility Management Entity (MME) 110 area including an MME 115 and an Evolved Universal Mobile Telecommunication System Terrestrial Radio Access Network (E-UTRAN) 120 and an Wideband Code Division Multiple Access (WCDMA) area 125 including a UTRAN 130 and a Mobile Switching Center (MSC) 135 are overlapped. The UE 105 is capable of communicating with the E-UTRAN 120 and UTRAN 130.
In order for the LTE UE 105 located in the LTE network to handle a Circuit-Switched (CS) call process, it is required to operate with CS Fall Back (CSFB) function. That is, once the network switching from the LTE network to the WCDMA network 125 has completed using the CSFB function, the UE 105 can place an outbound CS call or receive an inbound CS call. Once the CS call has been processed completed, the LTE UE 105 is capable of returns to the LTE mode according to a switching policy.
In order to achieve this, the LTE UE 105 has to follow the handling rules between E-UTRAN 120 and UTRAN 130 and between MME 115 and MSC 135.

Mobile communication system and paging message processing method thereof


The invention provides a novel structure of a phase change memory device. In the phase change memory device of the invention, an electrode acting as a radiating fin does not exit immediately above a phase change area of a phase change layer (115). A heater electrode (111) and landing electrode layer (113a, 114a) both contact the bottom of the phase change layer (115) made of GST. The landing electrode layer (113a, 114a) contacts the bottom of the phase change layer (115) to partially overlap in a region off from a portion immediately above the contact face (Y) of the phase change layer and heater electrode. The contact electrode (116, 118) is directly connected to the landing electrode layer (113a, 114a) in a portion off from a portion immediately above the heater electrode (111). The phase change layer of GST or the like does not exist immediately below the contact electrode.

The phase change memory device is a storage device using a phase change layer (chalcogenide alloy and the like) having the electrical resistance varying corresponding to its crystalline state, as a memory element. The chalcogenide alloy is an amorphous semiconductor including a chalcoge element.
FIG. 21 is a view showing part of the periodic table to explain chalcoge elements.
As shown in the figure, chalcoge elements include S (sulfur), Se (selenium) and Te (tellurium) of the sixth group of the periodic table. Application fields of the chalcogenide alloy are broadly divided into the optical disk and electrical memory. As a chalcogenide alloy used in the field of the electrical memory, there are known GeSbTe (hereinafter, referred to as GST) that is a compound of Ge (germanium), Te (tellurium) and Sb (antimony), AsSbTe, SeSbTe and the like.
FIGS. 22A and 22B are views to explain the principle of the phase change memory.
As shown in FIG. 22A, the chalcogenide alloy can form two stable states, an amorphous semiconductor state 10 and crystalline state 30, and it is necessary to supply heat exceeding an energy barrier 20 to cause transition from the amorphous state 10 to crystalline state 30.
As shown in FIG. 22B, the chalcogenide alloy of the amorphous state indicates high resistance. The high resistance state corresponds to a digital value of "1". The chalcogenide alloy of the crystalline state indicates low resistance. The low resistance state corresponds to a digital value of "0". Thus, by detecting a difference between current amounts (or voltage drop) passed through the chalcogenide alloy, it is possible to determine whether the storage information is "1" or "0", (i.e. to read the information).
Joule heat is used as heat to supply to the chalcogenide alloy for phase transition. In other words, by supplying pulses with different peak values and different durations to the chalcogenide alloy, Joule heat is generated in a contact face between an electrode and the chalcogenide alloy and its vicinity. The phase of the chalcogenide alloy changes by the Joule heat.
More specifically, the chalcogenide alloy becomes an amorphous state when supplied with heat near its melting point for a short time and cooled rapidly. Meanwhile, the chalcogenide alloy becomes a crystalline state when supplied with heat of its crystallization point lower than the melting point for a long time and then cooled.
For example, when GST is supplied with heat near its melting point (about 610° C.) for a short time (1 to 10 ns) and then cooled rapidly (for about 1 ns), GST becomes an amorphous state. Meanwhile, when GST is supplied with heat of its crystallization point (about 450° C.) for a long time (30 to 50 ns) and then cooled, GST becomes a crystalline state.
As shown in FIG. 22B, causing transition from the amorphous state to crystalline state is called "set (crystallization process)", and a pulse supplied to the chalcogenide alloy is called a "set pulse". It is herein assumed that the minimum temperature (crystallization temperature) required for crystallization is Tc, and that the minimum time (crystallization time) required for crystallization is tr.
Inversely, causing transition from the crystalline state to amorphous state is called "reset (non-crystallization process)", and a pulse supplied to the chalcogenide alloy is called a "reset pulse". The heat supplied to the chalcogenide alloy has temperatures near the melting point Tm, and the chalcogenide alloy is cooled rapidly after melting.
FIGS. 23A to 23D are views to explain a basic structure of a phase change memory device and the set/reset operation of the phase change memory device.
As shown in FIG. 23A, the phase change memory device basically has a structure that a chalcogenide alloy layer (phase change layer) 46 is sandwiched between upper and lower electrodes (48, 42). In addition, reference numeral 40 denotes a substrate, and reference numeral 44 denotes an electrical insulating film. A terminal P to which a set pulse or the like is applied is connected to the upper electrode 48, and the lower electrode 42 is fixed to the ground (reference potential).
As shown in FIG. 23B, the phase change memory device in FIG. 23A is equivalent to a resistance R1. As described above, a resistance value of the resistance R1 varies according to whether the chalcogenide alloy layer is an amorphous state or crystalline state. As shown at the left side in FIG. 23B, three kinds of pulses are input to the terminal P. A set pulse S1 has a peak value exceeding a threshold Vth. A reset pulse S2 has a peak value higher than that of the set pulse S1 and a width shorter than that of the set pulse S1. A read pulse S3 has a peak value less than the threshold Vth and a width wider than that of the set pulse S1. Herein, Vth is a voltage of lower limit to enable generation of Joule heat required for crystallization.
FIG. 23C shows correspondence between the set pulse S1 and increases in temperature caused by Joule heat generated by supply of the set pulse S1. FIG. 23C shows a waveform of the voltage on the upper side, and increases in temperature by Joule heat on the lower side.
A value of the voltage of the set pulse S1 exceeds the predetermined threshold Vth, and a time duration of the pulse is tcry. tcry is longer than the crystallization time tr (minimum time required for crystallization of the chalcogenide alloy). The temperature increased by Joule heat is significantly lower than melting point Tm, while being higher than the minimum temperature Tc (crystallization temperature) required for crystallization.
FIG. 23D shows correspondence between the reset pulse S2 and increases in temperature caused by Joule heat generated by supply of the reset pulse S2. FIG. 23D shows a waveform of the voltage on the upper side, and increases in temperature by Joule heat on the lower side.
As shown in the figure, a peak value of the reset pulse S2 largely exceeds the threshold Vth for crystallization, and a width of the pulse is sufficiently narrow. The increased temperature by Joule heat thereby exceeds melting point Tm of the chalcogenide alloy. Further, the time tamo taken from the peak of the increased temperature to crystallization temperature Tc is adequately short. The chalcogenide alloy is thereby once melted and then cooled rapidly, and as a result, is reset to an amorphous state.
FIG. 24 is a circuit diagram to explain the read operation in the phase change memory device. In FIG. 24, common portions to those in the figures described above are assigned the same reference numerals.
In FIG. 24, W indicates a word line, G indicates a ground line, and B indicates a bit line (that is a pulse input line connected to the terminal P to input the set pulse S1, reset pulse S2 and read pulse S3). Further, R1 indicates an equivalent resistance of the phase change memory element (comprised of a chalcogenide alloy layer 60).
M4 indicates an NMOS transistor (switching element) to select a memory cell, R2 indicates a current/voltage conversion resistance, A1 indicates a sense amplifier, and reference numeral 62 denotes a reference voltage source of the sense amplifier A1. I1 indicates a current passed through the memory cell in the read operation, and Vout indicates an output voltage (sensing output) of the sense amplifier A1.
In the set operation (in the same way as in the reset operation and read operation), the NMOS transistor M4 is turned on with the word line W being an active line, and then, a required pulse (one of S1 to S3) is input from the terminal P. The read pulse S3 is input in the read operation.
A resistance value of the resistance R1 varies whether the chalcogenide alloy layer 60 constituting a memory cell is an amorphous state or crystalline state, and in response to the resistance value, a current amount of the current I1 varies. Accordingly, by converting the current amount into a voltage value to read, it is possible to determine whether the stored information is "1" or "0".
The inventor of the present invention made various studies on the structure of the phase change memory device before the invention, and as a result of the study, found that following inconveniences can occur in the conventional structure.
As shown in FIG. 23A, the phase change memory device generally adopts a basic structure where a phase change layer (for example, GST) is sandwiched between upper and lower electrodes (for example, see JP 2005-159325). In other words, an electrode made of metal such as tungsten or the like exists on the phase change layer. The upper electrode made of metal such as tungsten or the like also has heat radiation characteristics. Accordingly, the conventional phase change memory element is regarded as having a structure such that a radiating fin is formed immediately above the phase change area.
As described above, since phase transition of the chalcogenide alloy layer is implemented by using Joule heat caused by applying the current, dissipation of Joule heat via the upper electrode (upper metal layer) leads to a reduction in thermal efficiency and is not preferable.
The reduction in thermal efficiency does not become a significant problem at the prototyping stage of discrete phase change memory element and memory LSI with a low degree of integration, but becomes a serious problem at the actual mass production stage of phase change memory device with a high degree of integration using the fine patterning process.
In other words, to increase the capacity of a phase change memory device, it is required to decrease the size of the memory cell, and therefore, a reduction in reset current (that is to restore the phase change layer from the crystalline state to amorphous state) is an important issue. That is, when a metal layer is laminated on the phase change layer, the upper metal layer functions as a radiating fin, and the thermal efficiency deteriorates, resulting in a factor for prohibiting the reduction in the current amount of the reset current. It is thus not possible to achieve a large scale of phase change memory LSI.
A technique is disclosed in JP 2003-332529 where a lower electrode (heater electrode) is formed in a shape with a pointed top, the contact face between the electrode and the phase change layer is thereby minimized to decrease the current, and radiation is thus suppressed. However, to process the lower electrode to the shape with a pointed top, specialized manufacturing process technique is required that is not used in typical LSI manufacturing, and it is undeniable that such a technique results in increases in complexity and cost.
Further, the upper metal layer has a predetermined thickness, and therefore, the heat also escapes from the side portion of the upper metal. Accordingly, decreasing the thickness of the upper metal layer is considered to suppress heat dissipation from the upper metal layer as much as possible. However, the decrease in the thickness of the upper metal layer makes the cross-sectional area smaller, increases the wiring resistance, and results in deterioration in circuit characteristics.
The upper metal layer acts as an etching stopper in making an opening for a contact hole in an interlayer insulating film, and prevents the undercoated phase change layer (for example, GST film) from being exposed. Accordingly, when the upper metal layer is thinned, in forming contact holes in the interlayer insulating film by etching, a risk occurs that the upper metal layer is penetrated, the phase change layer (for example, GST film) is exposed, and components of the phase change layer are volatilized and pollute the line.
When the phase change layer is partially exposed, such a problem may arise that components of the phase change layer are sublimated and disappear by heat treatment subsequently performed in embedding a metal layer to be contact electrodes. Further, it is feared that component gases of the phase change layer fill the contact hole, an adequate amount of the metal gas to form the contact electrode cannot reach the inside of the contact hole, and that failure occurs in growth of the embedded electrode.
Further, as described previously, the adhesion between the phase change layer and interlayer insulating film is regarded as being not good, and an adhesion layer comprised of an extremely thin film of metal such as titanium (Ti) or the like is sometimes provided between the layer and film. In this case, since the adhesion layer (Ti or the like) contacts the bottom of the phase change layer (for example, GST film), it may occur that components of both layers are bonded (for example, Ti (titanium) and Te (tellurium) are bonded), and the composition of the phase change layer changes in the contact face between the phase change layer and adhesion layer and its vicinity, resulting in an adverse effect on rewritable characteristics of the phase change layer.
Furthermore, the upper metal layer needs to be always provided to cover the top face of the phase change layer (GST film). In other words, the upper metal layer and the phase change layer (GST film) are paired, and cannot be divided in integration. Accordingly, it is not possible to use the upper metal layer in forming wiring and electrode in a peripheral circuit. Therefore, in forming wiring and electrode in a peripheral circuit, independently of processes of forming and processing a metal layer in a memory cell portion, it is necessary to newly add processes of forming and processing a metal layer, and the manufacturing process cannot be simplified.
Thus, it is undeniable that the thermal efficiency in writing (particularly, in reset) deteriorates in the phase change memory device with the conventional structure. Further, as described above, the problems exist in the mass production of a large scale of phase change memory LSI.
The present invention has been carried out based on the aforementioned consideration, and it is an object of the invention to achieve a phase change memory device of a structure with high thermal efficiency, and enable mass production of a large scale of phase change memory LSI while solving the problems due to mass production of the phase change memory device.

Phase change memory device and method of manufacturing the device


A method for manufacturing a sputtering target with which an oxide semiconductor film with a small amount of defects can be formed is provided. Alternatively, an oxide semiconductor film with a small amount of defects is formed. A method for manufacturing a sputtering target is provided, which includes the steps of: forming a polycrystalline In-M-Zn oxide (M represents a metal chosen among aluminum, titanium, gallium, yttrium, zirconium, lanthanum, cesium, neodymium, and hafnium) powder by mixing, sintering, and grinding indium oxide, an oxide of the metal, and zinc oxide; forming a mixture by mixing the polycrystalline In-M-Zn oxide powder and a zinc oxide powder; forming a compact by compacting the mixture; and sintering the compact.

1. Field of the Invention
The present invention relates to a method for manufacturing a sputtering target, a method for forming an oxide film, and a transistor.
2. Description of the Related Art
Transistors used for most flat panel displays typified by a liquid crystal display device or a light-emitting display device are formed using a silicon semiconductor such as amorphous silicon, single crystal silicon, or polycrystalline silicon provided over a glass substrate. Further, such a transistor employing such a silicon semiconductor is used in integrated circuits (ICs) and the like.
In recent years, attention has been drawn to a technique in which, instead of a silicon semiconductor, a metal oxide exhibiting semiconductor characteristics is used in transistors. Note that in this specification, a metal oxide exhibiting semiconductor characteristics is referred to as an oxide semiconductor.
For example, InGaO3(ZnO)m (m: a natural number) having a homologous phase is known as an oxide semiconductor (see Non-Patent Documents 1 and 2).
In addition, Patent Document 1 discloses a transparent thin film field-effect transistor including a homologous compound InMO3(ZnO)m (M represents In, Fe, Ga, or Al, and m is an integer greater than or equal to 1 and less than 50).

Method for manufacturing sputtering target, method for forming oxide film, and transistor

Semiconductor Energy Laboratory Co., Ltd.


The present disclosure is related to systems and methods for determining an optimal strategy. The method includes classify one or more users into a first user group and a second user group using an optimization model, wherein the first user group and the second user group correspond to two strategies, respectively. The method also includes obtain behavior data from terminals of the one or more users in the first user group and the second user group. The method further includes determine a first value of a parameter regarding the first user group and a second value of the parameter regarding the second user group using the optimization model. The method further includes determine a strategy based on the first value and the second value.

Strategy evaluation systems are widely used in various fields, such as online to offline services (e.g., a taxi service, a delivery service, an online shopping service), product research and development (R&D), advertisement, etc. Among them, A/B testing, is frequently used in the strategy evaluation systems, to evaluate performances of two strategies based on users' behavior data (e.g., user acceptances), and determine an optimal strategy. This patent application provides systems and methods to modify an NB test model in order to effectively improve the accuracy of the business strategy assessment. In addition, the A/B testing used herein, instead of one dimension, may be in multiple dimensions (e.g., age, gender, or education background), and thereby, providing more comprehensive users' feedback analysis and a more reliable optimal strategy.

Systems and methods for determining an optimal strategy

BEIJING DIDI INFINITY TECHNOLOGY AND DEVELOPMENT CO., LTD.


The present invention relates to an improved process for producing, by means of a portable foaming apparatus having a static mixer, a polyurethane foam by reacting a reaction mixture comprised of a polyol, an organic isocyanate, a foaming/frothing agent, and a reaction catalyst, the improvement comprising employing monochlorodifluoromethane as the sole blowing/frothing agent in said reaction in order to produce a CFC-free essentially closed-cell rigid or semi-rigid polyurethane foam. Also claimed is the foam produced by the above process.

In the production of polyurethane foams, a polyol is reacted with a polyisocyanate in the presence of a polyurethane catalyst and a blowing agent. Unfortunately, certain blowing agents, namely chlorofluorocarbons (so-called "CFCs"), are hazardous to the environment, specifically the ozone layer of the atmosphere. Hence, alternatives to the use of CFC's are being actively sought by the polyurethanes community.
The use of a portable foaming apparatus employing a foam forming formulation to provide on-site generation of polyurethane foam is well-known in the art. By way of illustration, U.S. Pat. No. 3,882,052 discloses the use of such an apparatus to provide non-froth polyurethane foam. For other applications, frothed foam is suitably produced using the portable foaming apparatus by incorporating into the foam forming formulation an auxiliary CFC blowing agent, such as dichloro-difouoromethane, commercially available as FREON 12, a product of DuPont Company. When injected into the foam forming mixture, the auxiliary blowing agent serves to augment the function of the static mixer in bringing about thorough blending of the foam forming ingredients. Since the auxiliary CFC blowing agent is hazardous to the environment, alternatives to the use of CFCs in the production of frothed foam would be highly desired by frothed foams manufacturers.
Heretofore, suitable alternatives have not been known based upon the knowledge of the present inventors.

On-site generation of polyurethane foam using an HCFC as a sole blowing agent


A network station subsystem architecture that uses a simplified interface reference discovery method and system is provided. In one embodiment a method for managing client-server communications is disclosed that includes providing a server with functions and interface methods; providing a client with references to the interface methods; and processing client requests by invoking the interface methods on the server via the references. Ideally, the interface methods are implemented by providing the server with a table of pointers to the functions, and providing the client with references to the table of pointers, ideally at the time of design. In another embodiment, a system for managing communications in a network station for a data-over-cable network having a plurality of network stations is provided. The system includes a plurality of components in the network station, each of the plurality of components having a functionality set and a table of pointers for the functionality set; a station manager having references to the tables of pointers in the plurality of components; and an interface manager for communication with the plurality of components and the station manager, the interface manager configured to process station manager requests for functionality from the components through the interface manager via the references to the tables of pointers.

The transmission of high-speed data via cable television systems involves the bi-directional transfer of Internet Protocol (IP) traffic over a cable system, typically an all-coaxial or hybrid fiber-coax (HFC) cable network. More particularly, and with reference to FIG. 1, the transmission path over such a cable system is realized at the head end by a cable-modem-termination system (CMTS) and at each customer location by a cable modem (CM). At the head end (or hub), the interface to the data-over-cable system is known as the cable-modem-termination system network-side interface (CMTS-NSI). At the customer locations, the interface is known as the cable-modem to customer-premises-equipment interface (CMCI). The system functions to transparently transfer IP traffic between these interfaces, including, but not limited to, datagrams, Dynamic Host Configuration Protocol (DHCP), Internet Control Message Protocol (ICMP), and IP group addressing (broadcast and multicast).
As described more fully in co-pending U.S. patent application Ser. No. 09/464,637, entitled Network Station Management System and Method, which is incorporated herein in its entirety, a networking manager is a cable modem management task interacting with the application-layer Internet Protocol (IP) components in order to establish and manage Internet connectivity. These IP components can include:
1. Dynamic Host Configuration Protocol (DHCP) Client
2. Trivial File Transfer Protocol (TFTP) for Configuration Download
3. Time of Day (TOD) Client
4. TFTP for New Software Download
5. Simple Network Management Protocol (SNMP) Agent
Each application-layer component is designed to run as a separate task. Each of these tasks use a messaging system (in this particular case Operating System (OS) provided messaging system) and send data to the networking manager in the body of the messages. This task design also enables the networking manager to perform other cable modem management functions (improving CPU bandwidth utilization) by checking on the application-layer task messages only as needed.
The Operations Support System Interface (OSSI) Management component is designed on the Object Oriented Design concept base. The reason for this is to allow sufficient flexibility to deal with the ever-changing OSSI requirements largely depending on control mechanisms through Management Information Base (MIB) Objects. The cable modem OSSI Client Manager is a task created at boot time. It has its own message queue to receive work from the Application-layer tasks or from the networking manager task and it sends messages to the networking manager task.
Thus, the OSSI subsystem architecture is based on a simplified component object model. Each component in this architecture can act as a server or a client. A server component implements a certain functionality set. It exposes its functionality set through interfaces. An interface is an invariant contract that defines the interaction between the server and the client components. An interface is represented by a set of methods whose signatures (function prototypes) never change but whose implementation may change.
For a client to use methods in a server's interface, a client must be able to access the functions through the interface. Hence, there is a need for a method and architecture that enables rapid and efficient client access to the functions embodied in a server interface.

System and method for interfacing network station subsystems


A system and method for facilitating rendering a user interface display screen or portion thereof. An example method includes determining context information associated with a user, wherein the context information includes use job role information; and employing the context information to select one or more visualization types from a set of available visualization types. The method may further include using the context information to provide one or more first user options to select one or more categories of data pertaining to a business task; referencing the one or more categories to facilitate determining one or more data attributes, dimensions, or measures associated with the context information; utilizing the one or more data attributes and the context information to select the one or more visualization types from the set of available visualization types; and providing a second user option to choose a visualization type from among selected visualization types.

The present application relates to software and more specifically to user interface designs and methods for graphically displaying and interacting with data and/or concepts.
Software for facilitating information visualization, report generation, or analytic generation is employed in various demanding applications, including enterprise resource planning, scientific research, digital libraries, data mining, financial data analysis, market studies, manufacturing production control, drug discovery, and so on. Such applications often demand task-specific illustrative user interface display screens and accompanying visualizations for clearly illustrating data and accompanying characteristics, patterns, and interrelationships.
Space-efficient and illustrative visualizations are particularly important in enterprise applications, where data sets can vary widely, and where many types of visualizations may be available to render underlying data and provide associated software functionality. Visualizations for interpreting enterprise data may intuitively convey meaning inherent in underlying data and may include software functionality for exploiting the information to answer key business questions and to facilitate informed decision making.
Conventionally, software for visualization of enterprise data lacks effective mechanisms for facilitating custom visualization construction beyond specifying visualization source data and superficial visual encoding of rendered data attributes. For example, certain visualization software may include tools for facilitating creation of a pie chart from dimensions of a database table and may include user options for selecting colors for different slices of the pie chart.
Accordingly, conventional enterprise visualization software typically relies upon data characteristics to drive visualization creation, such that the resulting visualizations are tailored to the source data. However, users may not know what relationships they are seeking among data to be visualized, and consequently, may have difficulty selecting an appropriate visualization from a potentially large list of available visualizations.
Furthermore, users may become overwhelmed by potentially unnecessary or irrelevant source data, and users may not know what type of visualization to employ to render or otherwise display data. For example, a user may not know whether a pie chart, line graph, or tree diagram, sunburst visualization, or galaxy visualization would provide the most illustrative representation of the data for what the user is attempting to accomplish.
Hence, since users may not know what insight they seek or what questions they want answered, users often rely upon guesswork when selecting visualizations. However, such guesswork can inhibit informed decision making, resulting in potentially important decisions being made without critical insight.


A machine learning technique is used to improve dynamic prediction of processor utilization for multi-threaded user-level applications in a dynamic run-time environment based on processor utilization history. Processor supply voltage and processor clock frequency may be dynamically scaled based on the predicted processor utilization in order to reduce processor power consumption.

Power dissipation (P) of a device is dependent on capacitance (C), clock frequency (f) and supply voltage (V), with P=CfV2. The upper limit of the clock frequency is determined by supply voltage, thus a reduction in the supply voltage results in corresponding reduction in power dissipation. However, the reduction in the supply voltage of a device results in an increase in delay through the device which results in slowing down the execution time of an application.
When memory or an Input/Output (I/O) interface in a system is busy during run-time, for example, due to last-level cache misses to memory, computation performed by the processor is not on the critical path. For traditional server application workloads, cache-misses may account for 20% of processor cycles. Thus, when high computation speed of the processor is not required, the clock frequency/supply voltage of the processor may be reduced in order to reduce the energy consumption of the system. Typically, in order to reduce power dissipation, a processor may support multiple power states and provide a software interface for handling a request to change to a lower or higher power state.
Dynamic Voltage and Frequency Scaling (DVFS) is one technique that is typically used to provide power optimization during run-time. DVFS may be performed in hardware, in an operating system (OS), or in a user-level application. A hardware-level DVFS monitors processor load and scales the processor's supply voltage without involvement of software or OS. An OS-level DVFS uses heuristic scheduling based on a fixed time interval or scheduled tasks to perform DVFS. User-level DVFS enables a user application to profile processor utilization during execution and scale the processor's supply voltage or clock frequency up or down. Typically, a just-in-time (JIT) compiler is used to recompile the user application so that it can perform DVFS.
However, in a multi-threading environment, it is possible that one user application may scale down the processor's supply voltage and clock frequency, but another computation-intensive program may need a higher clock frequency before the supply voltage is scaled up. Thus, this results in extended execution time of the computation-intensive application.
Although the following Detailed Description will proceed with reference being made to illustrative embodiments of the claimed subject matter, many alternatives, modifications, and variations thereof will be apparent to those skilled in the art. Accordingly, it is intended that the claimed subject matter be viewed broadly, and be defined only as set forth in the accompanying claims.

Method and apparatus for dynamic voltage and frequency scaling


A sealing device is for sealing fluid transmittable openings in well components. The sealing device includes an elastic element which is arranged between two shoulders. The elastic element, before being placed in the fluid transmittable opening, has a larger external dimension than the fluid transmittable opening to be sealed. A gap is arranged between at least one of the shoulders and the elastic element, allowing liquid to enter between the shoulder and the elastic element. The ridge is arranged on an intermediate piece which is located between the shoulder and the elastic element. The intermediate piece is constituted by as ring in which the ridge is surrounding and divided, and projects from an end surface opposite an abutment surface facing the elastic element.

When sealing fluid transmittable openings in a well, such as in a petroleum well, it is usual to move a seal having an elastic element of a larger external diameter than the diameter of the fluid transmittable opening to be sealed, into the fluid transmittable opening. By the elastic element being arranged between two shoulders, the volume that the elastic element may occupy is restricted, whereby a greater surface pressure is achieved between the elastic element and the inner jacket of the fluid transmittable opening, as compared to if the elastic element could lengthen freely.
During operation, damage may occur in the sealing surface of well components. For example, during wireline operations in the well, it is not unusual for one or more axial grooves to be worn into the sealing surface of a downhole safety valve. Other causes may cause other types of damage in the sealing surfaces.
Known seals often cannot be brought to seal damaged fluid transmittable openings. The reason is that the damage is not filled by the elastic element and thereby sufficient sealing of the damage for a differential pressure to be established across the elastic element is not achieved.
As known seals notoriously provide an unreliable seal, it is usual to place a seal outside the damaged sealing surface. Seals of this kind may be functionally unreliable, which has turned out to possibly result in operational interruptions and need for repairs.

International Research Institute of Stavanger AS


A user terminal comprising: a positioning system arranged to detect a geographical location of the user terminal; a transceiver for communicating with other user terminals via a communication network; and a communication processing apparatus coupled to the transceiver and positioning system. The communication processing apparatus is arranged to detect communication events occurring via the transceiver and communication network in relation to other user terminals, and to maintain a log of the communication events. Further, the communication processing apparatus is configured to organize the log in dependence on a geographical location detected by the positioning system.

Some communication systems allow the user of a terminal, such as a personal computer or mobile terminal, to conduct voice or video calls over a packet-based computer network such as the Internet. Such communication systems include voice or video over internet protocol (VoIP) systems. These systems are beneficial to the user as they are often of significantly lower cost than conventional fixed-line or mobile networks. This may particularly be the case for long-distance communication. To use a VoIP system, the user installs and executes client software on their terminal. The client software sets up the VoIP connections as well as providing other functions such as registration and authentication. In addition to voice communication, the client may also set up connections for other communication media such as instant messaging ("IM"), SMS messaging, file transfer and/or voicemail.
One type of communication system for packet-based communication uses a peer-to-peer ("P2P") topology. To enable access to a peer-to-peer system, a user executes P2P client software supplied by a P2P software provider on their terminal, and registers with the P2P system. When the user registers with the P2P system, the client software is provided with a digital certificate from a server. This may be referred to as a "user identity certificate" (UIC). Once the client software has been provided with the certificate, then calls or other communication connections can subsequently be set up and routed between end-users ("peers") of the P2P system without the further use of a server in the call set-up. Instead, the client looks up the required IP addresses from information distributed amongst the P2P client software on other end-users' terminals within the P2P system. That is, the address look-up list is distributed amongst the peers themselves. Once the IP address of a callee's terminal has thus been determined, the caller's P2P client software then exchanges UIC certificates with the callee's P2P client software. The exchange of these digital certificates between users provides proof of the users' identities and that they are suitably authorised and authenticated in the P2P system. Therefore the presentation of digital certificates provides trust in the identity of the users.
It is therefore a characteristic of peer-to-peer communication that, once registered, the users can set up their own communication routes through the P2P system in at least a partially decentralized manner based on distributed address look-up and/or the exchange of one or more digital certificates, without using a server for those purposes. Further details of an example P2P system are disclosed in WO 2005/008524 and WO 2005/009019.
VoIP or other packet-based communications can also be implemented using non-P2P systems that do use centralized call set-up and/or authentication, e.g. via a server.
In a communication system it is often useful for the client application to maintain a log of past communication events. This helps improve operation of the network by facilitating continuity in threads of communication. For example a thread could comprise a chain of related communications such as calls or IM sessions between the same two or more users. If one or more communications are postponed or missed, then the log will enable those communications to be more readily identified and therefore the thread of communication can be more efficiently recovered by a user at a later date.
A conventional communication client application provides the user with the ability to retrieve a log of calls that they have made, received or missed. The log may also record other communication events such as IM sessions or voicemail messages. These logs comprise a list of communication events which are typically sorted chronologically and which record the type of call or event that took place, who the call was with, and the time of the event.

Logging communication events using location information