A LAN elevator network includes (a) a pair of redundant car buses for exchanging signals with car control system elements, (b) a pair of redundant group buses for exchanging signals with the redundant car buses by means of a car-group bridge, and (c) with a pair of redundant building buses, which exchange messages with a building controller, by means of a group-building bridge. Communication among all nodes on the car bus, group bus, and building bus occurs by means of a single protocol. Each communications element on a bus communicates with the bus by means of a communications coprocessor including a transmitter and a receiver.

In an elevator system similar to that described in co-pending allowed application Ser. No. 07/029,495, entitled "Two-Way Ring Communication System for Elevator Group Control" (filed Mar. 23, 1987), the disclosure of which is incorporated herein by reference, elevator group control may be distributed among separate microprocessors, one per car in the group. These microprocessors, known as operational control subsystems (OCSS), are all connected together in a two-way ring network. Each OCSS has a number of other subsystems and signaling devices, etc., associated with it, as will be described more fully below; only one such collection of subsystems and signaling devices is illustrated in FIG. 1 for the sake of simplicity.
The hall buttons and lights are connected with remote stations and remote serial communication links to the OCSS via a switch-over module. The car buttons, light, and switches are connected through similar remote stations and serial links to the OCSS. The car specific hall features, such as car direction and position indicators, are connected through remote stations and remote serial link to the OCSS.
The car load measurement is periodically read by the door control subsystem (DCSS), which is part of the car controller. This load is sent to the motion control subsystem (MCSS), which is also part of the car controller. This load in turn is sent to the OCSS. DCSS and MCSS are microprocessors controlling door operation and car motion under the control of the OCSS, with the MCSS working in conjunction with the drive and brake subsystem (DBSS).
The dispatching function is executed by the OCSS, under the control of an advanced dispatcher subsystem (ADSS), which communicates with the OCSS via an information control subsystem (ICSS). The car load measured may be converted into boarding and deboarding passenger counts using the average weight of a passenger by the MCSS and sent to the OCSS. The OCSS sends this data to the ADSS via ICSS.
The ADSS through signal processing inter alia collects the passenger boarding and deboarding counts at the various floors and car arrival and departure counts, so that in accordance with its programming, it can analyze the traffic conditions at each floor. The ADSS can also collect other data for use in making predictions, etc., if so desired.
This ring system has problems.
Communication between each node in the system is point-to-point, i.e. from, for example, the drive control to the motion control or from the motion control to the operational control. Nodes are any communications element on a bus. If it is desired to move a message from the drive control to the operational control, the message must take two transmissions-one transmission from the drive control to the motion control and a second transmission from the motion control to the operational control. Because communication is point-to-point, the time required for communication is increased; the message must pass through many communication nodes, be decoded, interpreted, and encoded at each node along the message route. For the same reason, the communications computing requires complicated, expensive, and redundant software.
Second, this communication system requires that an applications microprocessor associated with a node perform communications functions in addition to the application functions for which the host microprocessor was designed, for example, in the case of the drive and brake subsystem, directing movement of the machine and sheave and brake. Therefore, the microprocessors, such as the DBSS, do not perform their applications as well as they might.
Third, it is difficult to add a node to the system; doing so requires each node in the communications path between the transmitting node and the receiving node to be loaded with the hardware and software for transmitting and receiving messages from the transmitting node, even though this intermediary node is not going to use that message. For example, if EMS wants to send a message to ADSS, then ICSS 1 and each OCSS within the communications path, as well as ICSS 2, must be retrofitted with the hardware and software for handling an EMS message. This need for retrofitting each intermediary node with the hardware and software for a message is more pernicious when not only is this particular message not meant for the intermediary transceiver node (for example OCSS), but none of the messages from the transmitting node (for example, EMS) are ever used by the intermediary node for performing its main function.

Local area network eleveator communications network


Fine adjustment of the rotation speed ratio or intentional control of the rotation speed ratio is carried out, centered on a desired speed ratio, including 1:1, for the rotation speed ratio between an input shaft and an output shaft. A planetary-roller speed-increasing mechanism whose input shaft is a carrier and whose output shaft is a sun roller, a planetary-roller speed-reduction mechanism whose input shaft is a sun roller and whose output shaft is a carrier, and a worm speed-changing mechanism for rotationally driving a roller ring in contact with planetary rollers of the planetary-roller speed reduction mechanism are provided in a housing. The output shaft of the planetary-roller speed-increasing mechanism and the input shaft of the planetary-roller speed-reduction mechanism are linked.

1. Field of the Invention
The present invention relates to planetary-roller-type continuously variable transmissions disposed between a driving mechanism and a mechanism being driven, and also relates to planetary-roller-type continuously variable transmissions suitable for use in cases where the rotation speed ratio of the output shaft to the input shaft thereof is minutely adjusted or intentionally controlled, centered around a predetermined speed ratio, including 1:1.
This application is based on patent application No. 2004-173019 filed in Japan, the content of which is incorporated herein by reference.
2. Description of Related Art
Until now, there has been a great demand for continuously variable transmissions. For example, in the case where the driving mechanism is an electric motor, when changes occur in the operating environment, such as the voltage supplied to the electric motor, it may not be possible to obtain the predetermined rotation speed ratio between the output shaft of the electric motor and the input shaft of the mechanism being driven. In such an event, it is necessary to adjust the rotation speed ratio by means of a mechanical adjuster.
Also, when winding threads in spinning mills, the length of the circumference for winding up the thread changes as thread winding proceeds, and therefore, it is necessary to adjust the thread winding speed. As means to solve these problems, apparatuses such as chain-type continuously variable transmissions have been used.
In recent years, it has become necessary to carry out rotation speed ratio adjustment in the fields of printing presses, measurement instruments, vehicular steering systems, and so on, and there have been demands for high-quality power transmission devices producing low noise and having compactness, extremely low backlash, extremely low rotation variation, high efficiency, high reliability, and so on.
An example of this type of technology is given in Japanese Patent Application Publication No. 2004-58896, which discloses a steering apparatus including a differential transmission mechanism in a steer-by-wire system.

Planetary-roller-type continuously variable transmission


An electrodeless lighting system includes: a resonator which is installed at an exit of a wave guide for guiding microwave generated from a magnetron and making light pass and microwave resonate therein; a bulb positioned in the resonator and having a luminous portion filled with a luminous material emitting light by the microwave energy and a shaft portion integrally extended from the luminous portion; a resonance control member disposed inside the resonator and having a height controlled according to a position of the luminous portion of the bulb and the entire length of the resonator so as to make optimum resonance of the microwave; and a reflector positioned around the resonator for reflecting light emitted from the bulb. Accordingly, the electrodeless lighting system can facilitate light distribution for achieving lateral lighting and a wider range of lighting and simultaneously improve lighting efficiency.

1. Field of the Invention
The present invention relates to an electrodeless lighting system, and more particularly, to an electrodeless lighting system capable of facilitating light distribution for achieving lateral lighting and a wider range of lighting and simultaneously improving lighting efficiency.
2. Description of the Background Art
In general, an electrodeless lighting system using microwaves is a device for emitting visible light and ultraviolet light upon applying microwave energy to an electrodeless plasma bulb. The electrodeless lighting system has a longer life span than that of incandescent lamp or fluorescent lamp which is generally used, and has higher lighting effect
FIG. 1 is a sectional view showing a structure of a conventional electrodeless lighting system.
As shown therein, in the conventional lighting lamp system, a high voltage generating unit 2 for raising a common AC voltage to a high voltage is installed at one side in a case 1, and a magnetron 3 for generating microwave by a high voltage supplied from the high voltage generating unit 2 is installed at the other side of the case 1.
And, a wave guide 4 is installed inside of the case 1 and communicates with an output portion 3a of the magnetron so that microwave generated by the magnetron 3 passes through the wave guide 4. An exit 4a of the wave guide 4 is exposed out of the case 1 through an aperture of the case 1.
In addition, a rotary shaft 5 is rotatably coupled at a shaft hole 4a formed at a central portion of the wave guide 4 in a vertical direction. A bulb 7 filled with a material which emits light by microwave energy is installed at an upper end portion of the rotary shaft 5 protruding outwardly through the exit 4a of the wave guide 4. A bulb rotating motor 8 having a motor shaft 8 connected to the rotary shaft 5 in the wave guide 4 by a connection pipe 7 is installed at a lower end portion of the rotary shaft 5 outside the wave guide 4 in order to rotate the rotary shaft.
And, a mesh-structured resonator 9 having a predetermined height (H) is coupled to the exit 4a of the wave guide 4, which is positioned outside the case 1, encompassing the bulb 6. The resonator 9 blocks leakage of electromagnetic waves introduced through the wave guide 4 and simultaneously passes light emitted from the bulb 6. A reflector 10 is fixed around the resonator 9 to cover the outer side of the resonator 9 in order to reflect light which has passed through the resonator 9 after generated in the bulb 6.
The resonator 9 is designed to use a TE mode (Transverse Electric mode). Because only one basic mode is used, intensity of an electric field is strongest at a central portion of the resonator 9. Accordingly, the bulb 6 is installed at a central portion (h) of the resonator, where the intensity of the electric field is strongest.
In addition, a cooling fan assembly 14 including a fan motor 11, a cooling fan 12 and a fan housing 13 having an outlet 13a is installed at a lower side of the case 1 so as to cool the magnetron 3 and the high voltage generating unit 2.
And, an inlet 13b through which external air is sucked by rotation of the cooling fan 12 is formed at the fan housing 13. A plurality of discharge openings 1b are formed at an edge of an upper surface of the case 1 so that the air sucked through the inlet 13b can be discharged outside by way of the high voltage generating unit 2 and the magnetron 3.
Non-described reference numeral 15 in the drawing is a dielectric mirror.
An operation of the conventional electrodeless lighting system constructed as above will now be described.
When power is applied, a high voltage is generated in the high voltage generating unit 2, the generated high voltage is supplied to the magnetron 3, and microwave is generated by the applied high voltage in the magnetron 3.
The generated microwave is radiated into the resonator 9 through the wave guide 4, a material within the bulb 6 is electrically discharged by the radiated microwave to thereby generate light by plasma, and the generated light is thrown to the front by being reflected by the dielectric mirror 14 and the reflector 10.
And, the bulb rotating motor 8 rotates the rotary shaft 5 so that a temperature of the bulb 6, which is raised by the light generated in the bulb 6, does not exceed a predetermined temperature
In addition, the fan motor 11 installed at a lower portion inside the case 1 rotates to rotate the cooling fan 12. External air sucked through the inlet 13b by the rotation of the cooling fan 12 flows through the outlet 13a, cools the high voltage generating unit 2 and the magnetron 3, and then is discharged outside the case 1 through the discharge opening 1b formed at the upper surface of the case 1.
However, in the conventional electrodeless lighting system constructed as above, in order to make lateral lighting and wide-area lighting in a basic mode, a distance (h) between a central portion of the bulb 6 and the dielectric mirror 15 is to be designed to be longer. As the distance (h) therebetween becomes long, a height (H) of the resonator should be designed to be longer, and, if the size of the resonator 9 becomes great in such a manner, a higher mode has to be used. If the higher mode is used, a loss of the microwave becomes great in the basic mode, thereby causing not only a size increase of the entire electrode lighting system but also remarkable deterioration in lighting efficiency. Accordingly, the conventional electrodeless lighting system has a problem in that light distribution for achieving lateral lighting and wide-area lighting is difficult.
In addition, if the higher mode is used as described above, a matching characteristic of frequency becomes different from that in a basic mode. Accordingly, a shape of a feeding hole formed at the exit of the wave guide, for outputting microwave into the resonator becomes very complicated, thereby making a design of an electrodeless lighting system for frequency matching complicated.


The invention is a non-contact optical tape tension sensor for a tape drive. A light source directs an incident beam to the tape in a region of the tape path near where the tape bends. The amount of divergence of the reflected light is related to the curvature of the tape, and thus to the tape tension. The reflected light is passed through an aperture to a photodetector that detects the amount of the divergent beam passing through the aperture. The photodetector output is input to the tape drive controller that controls the currents to the supply and take-up motors to thereby maintain the tape tension within the desired range.

This invention relates generally to tape drives, and more particularly to a magnetic recording tape drive with an improved system for detecting and controlling tape tension.
In tape recording systems, such as reel-to-reel type magnetic recording tape drives, the tape tension and velocity are controlled to provide a stable recording speed as well as a stable distance between the recording head and the recording surface of the tape. In low performance tape drives with relatively low accelerations to bring the tape up to the desired velocity, direct measurement of tape tension is not required. This is because a tape tension signal can be derived from the motor torque vs. current characteristics for the supply and take-up motors and from the supply and take-up reel speeds, which are inversely proportional to the diameters of the tape packs on the tape reels.
A typical magnetic recording tape drive, wherein tape tension and velocity are controlled, is shown schematically in FIG. 1. The tape drive includes a tape supply reel 15 containing tape pack 13 and driven by supply motor 16, a tape take-up reel 17 containing tape pack 14 and driven by take-up motor 18, a recording head 20 and guides, 22, 24 for guiding the tape 25 past the recording head 20. Tachometers 26a, 26b for the supply motor 16 and take-up motor 18, respectively, continually sense the supply and take-up motor speeds. A controller 30 provides output signals 23, 27 to control the motor currents to supply motor 16 and take-up motor 18, respectively. An estimator 34 is used to provide the required tape tension signal 35 and tape velocity signal 37 which are input into controller 30. The estimator 34 receives motor speed signals 31, 33 from tachometers 26a, 26b respectively, and motor current signals 23, 27 from controller 30. The estimator 34 uses the motor speed inputs (to determine the diameters of the tape packs 13, 14) and the motor current inputs (with known motor torque vs. current characteristics) to estimate the tape tension, which is fed back as signal 35 into controller 30. The estimator 34 also provides an estimate of tape velocity as signal 37 input to controller 30. A tape tension control system that estimates tape pack diameters to control motor currents is described in U.S. Pat. No. 4,408,144.
Tape drives like those depicted in FIG. 1, such as the current linear-tape-open (LTO) tape drives, do not require direct measurement of tape tension and thus do not have a separate tape tension sensor. However, future generations of type drives, especially high performance tape drives with high acceleration to bring the tape up to the desired velocity, will require direct measurement of tape tension to handle the thinner tapes that will be used. Some tape drives, like the IBM 3590, use a fixed pin tape guide in the tape path and measure tape tension directly by measuring the air pressure between the tape and the fixed pin guide. This type of direct tape tension measurement is described in U.S. Pat. No. 4,842,177. However, in tape drives such as the IBM LTO tape drive that use rollers as tape guides in the tape path instead of fixed pins, it is not possible to measure air pressure between the tape and the rollers.
Other alternatives for directly measuring tape tension have been proposed that require physical contact with the tape and/or additional components in the tape path. These include tension arms, strain gauges on roller mounts, and optical measurement of tape displacement in a flat region of the tape path. The use of an optical sensor to measure tape displacement in a flat region of the tape path is described in xe2x80x9cVacuum Puffer Head to Prevent Tape Stick on Magnetic Headxe2x80x9d, IBM Technical Disclosure Bulletin, May 1988, pp. 242-243 and xe2x80x9cTape Tension Detectionxe2x80x9d, IBM Technical Disclosure Bulletin, November 1983, pp. 2990-2991, both of which require the use of a vacuum region in the tape path, in Japanese published patent application JP-08122176A (May 17, 1996) that requires an air blower in the tape path, and in Japanese published patent application JP-2001035046A (Feb. 9, 2001) that measures tape width.
What is needed is tape drive with a tape tension sensor that does not require physical contact with the tape or additional rollers, guides or other components in the tape path.
The invention is a non-contact optical tape tension sensor for a tape drive. A light source directs an incident beam to the tape in a region of the tape path near where the tape bends. The amount of divergence of the reflected light is related to the curvature of the tape, and thus to the tape tension. The reflected light is passed through an aperture to a photodetector that detects the amount of the divergent beam passing through the aperture. The photodetector output is input to the tape drive controller that controls the currents to the supply and take-up motors to thereby maintain the tape tension within the desired range.
For a fuller understanding of the nature and advantages of the present invention, reference should be made to the following detailed description taken together with the accompanying figures.

Tape drive with non-contact optical tape tension sensor

International Business Machines Corporation


Methods and apparatus for enhancing Mobile IP signaling and to support use of disparate addressing plans and dynamic Home Agent allocation in Mobile IP Regional Tunneling are described. The enhanced methods of signaling use an intermediate node, e.g., a Gateway Foreign Agent, straddling different addressing domains, when the signaling controls a process between the intermediate node and an upstream node. The specific intermediate node, its interfaces and upstream addresses can be dynamically selected. The Enhanced MIP signaling includes dynamic allocation of: a regional node at a Foreign Agent, the upstream address of a regional node by the regional node, a Home Agent for a regional node prior to dynamic allocation of the regional node. A method is supported to indicate to a Mobile Node that a dynamically allocated regional node has become invalid triggering enhanced MIP signaling dynamically allocating a new regional node and upstream interface address.

For the purpose of understanding the invention it is useful to have a basic understanding of Mobile IP. Mobile IP (v4/v6), also indicated as MIPv4 [MIPv4] and MIPv6 [MIPv6], enables a mobile node (MN) to register its temporary location indicated by a care-of-address (CoA) to its Home Agent (HA). The HA then keeps a mapping (also called a binding) between the MN's permanent address, otherwise called Home Address (HoA), and the registered CoA so that packets for that MN can be redirected to its current location using IP encapsulation techniques (tunneling).
The CoA used by a MN can be an address that belongs to a Foreign Agent (FA) when MIPv4 is used or, in MIPv4 and MIPv6, it can be a temporarily allocated address to the MN itself in which case is called a collocated care-of-address (CCoA).
The concepts and solutions described here are applicable to both MIPv4 and MIP unless otherwise mentioned.
Regional tunneling (REGTUN) is one technique sometimes used in conjunction with Mobile IP. This approach uses a Gateway Foreign Agent (GFA) between the FA and the HA to improve MIP signaling. Specifically, the MN can register the local GFA CoA into the HA using an MIP registration with the HA that is routed via the GFA. Then each binding update under the same GFA goes just to the GFA instead of the HA, and changes the FA CoA for the GFA. The GFA switches the GFA CoA traffic for the specific HoA into the FA CoA matching that HoA and GFA CoA. The GFA update is a regional registration and it avoids having to refresh the HA on each hand-off which is a bandwidth and latency gain because the HA could be a very distant node from the FA/GFA.
The problem with this draft (http://www.ietf.org/proceedings/01dec/I-D/draft-ietf-mobileip-reg-tunnel-05.txt) is that the signaling scheme assumes that the two addressing schemes are the same either side of the GFA, and no support is enabled for dynamic HA allocation, both of which are common requirements in MIP. Therefore, a need exists for apparatus and methods that will support disparate addressing plans and dynamic HA address allocation in MIP signaling.

This patent is subject to a terminal disclaimer.

Support of disparate addressing plans and dynamic HA address allocation in mobile IP


An information processing device for providing a program selected on the basis of a predetermined theme among recorded programs and programs to be received to a user. A special program is generated by selecting a predetermined program on the basis of a predetermined theme such as ‘person of the today’, ‘hot drama’, among recorded programs and programs to be received to a user and the contents of the selected program is displayed on a screen as information of a recommendation program. The contents of the special program are changed according to preference of the user, a displaying time of the screen, and setting by the user.

1. Field of the Invention
The present invention relates to an information processing device, a method of processing information, and a program. More particularly, the present invention relates to an information processing device capable of providing a program selected on the basis of a predetermined theme among recorded programs and programs to be received to a user, a method of processing information, and a program.
2. Description of the Related Art
A digital recording device such as a hard disk recorder or the like having been sold in recent years has a function for selecting a desired program among recorded programs and presenting the selected program as a recommendation program to a user.
Further, the digital recording device, for example, selects a desired program on the basis of the setting by the user or program information of the recorded program acquired from an EPG (electronic program guide) such that a program of a genre selected by the user or a program having a keyword selected by the user included in a title can be a recommendation program.
In addition, the digital recording device may have a function for analyzing a preference of the user on the basis of an operation history or the like or automatically selecting the recommendation program without depending on the setting by the user. For example, JP-A-2004-355340 discloses a technology for matching a preference vector that indicates preferences of users and a program vector that indicates a feature of each program acquired from program information and for selecting a recommendation program on the basis of the matching result. JP-A-2004-355340 also discloses a technology for displaying the selected recommendation program with a reason of recommendation.
However, the digital recording device according to the related art can select the recommendation program and present it to the user, but the digital recording device displays the title of the corresponding program with the reason of the recommendation by a list. Accordingly, it is hard to induce interesting from the user and the user cannot easily check the reason why the corresponding program is the recommendation program.
The user may easily check the recommendation program by displaying the information of the recommendation program in a form of outlines of a plurality of special articles published in a magazine with photos, like a cover or a list of the magazine, not just a list of the title.
In addition, colors of characters used for the titles of the programs displayed as a list are the same. Accordingly, it is difficult to check or use the titles displayed on one screen.

Information processing device, method of processing information, and program


The embodiments herein relate to a mobile terminal and a method for accessing a wireless network in a roaming environment, the mobile terminal being pre-provided with credentials to access the wireless network, the mobile terminal further being provided with an application, said application includes a service part and an application part. The mobile terminal is configured to: send a request to a EAP server, the request including the credentials of the mobile terminal; connect the service part of the application to an access control server which adds/creates an EAP account for the mobile terminal for a predetermined time period; and to access the wireless network when the EAP server validly authenticates the credentials of the mobile terminal. The embodiments also relate to a method in the access control server and to the server.

With the advent of Internet access mobile communications technology, so also has evolved the presence of WiFi Internet access locations (i.e., hotspots provided by a network operator) where an Internet access mobile terminal may gain access to an Internet connection and Internet content. Such WiFi Internet access locations may comprise locations including but not limited to commercial services locations (i.e., restaurants, hotels and other retail sales establishments), public services locations (i.e., airports, other transportation terminals, libraries and government offices) and private locations (i.e., residences). These hotspots are also referred to as Open WiFi networks.
While ready mobile access to Internet service and Internet content is desirable within the context of the information technology art, ready mobile access to Internet service and Internet content is nonetheless not entirely without problems within the information technology art. In that regard, WiFi hotspots of an operator available to mobile terminals need to be managed by the operator in a way that is seamless to the mobile terminals especially when mobile terminals roam in a network comprising such WiFi hotspots. The greater the number of hotspots the more difficult it is for an operator to manage such a network.
Thus, desirable are apparatuses, methods and program product that provide for seamless connectivity within the context of mobile connectivity to a plurality of WiFi hotspots in a roaming environment, in such a way as to facilitate for the operator control of the access to the network as well as to facilitate for the mobile terminal access to the network.

Methods and apparatuses for conditional WiFi roaming


A method, system and apparatus for obtaining a parameter of interest from a plurality of sensors in a fiber optic cable deployed in a wellbore are disclosed. Light having variable frequency within a range of frequencies is propagated along the fiber optic cable. Signals are received that are responsive to interaction of the propagated light with the plurality of sensors. The received signals are filtered using a programmable filter. The parameter of interest is obtained from the filtered signals. In one aspect, the fiber optic cable is coupled to a member deployed in the wellbore and the parameter of interest is related to the member.

1. Field of the Disclosure The present disclosure relates to obtaining a parameter of interest in a swept-wavelength interferometry systems for use in wellbores.
2. Description of the Related Art
In various aspects of oil exploration and production, optical sensors are deployed downhole and a light source at a surface location supplies light to the optical sensors over a fiber optic cable. Light interacts with the optical sensors to produce a reflected light having a signal that is returned to the surface to be measured. Typically, the returned light is sampled at a sampling device which is controlled using a trigger signal obtained from a suitable source, such as the light source. When sampling signals, a sampling frequency is generally selected that prevents false reconstruction of the original signal, a process known as aliasing. The highest signal frequency that can be successfully reconstructed for a selected sampling frequency is known as the Nyquist frequency. Some systems currently in use include anti-aliasing filters that remove signals above a selected fixed cut-off frequency of the filter. However, if the signal frequency is changing, as in swept-wavelength systems, such filters may be inadequate. The need to design systems to prevent signal aliasing introduces factors that constrain the utility of the system, or can reduce data fidelity. The present disclosure therefore provides a method and apparatus for moderating these constraints and/or improving the data fidelity in swept-wavelength systems.

Programmable filters for improving data fidelity in swept-wavelength interferometry-based systems


A unified frame structure for filter bank multi-carrier (FBMC) and orthogonal frequency division multiplexed (OFDM) waveforms may allow FBMC and OFDM frames to be communicated over a common channel without significant inter-frame gaps. The unified frame structure may set an FBMC frame duration to an integer multiple of an OFDM frame element duration to enable alignment of FBMC frames and OFDM frames in the time domain. The unified frame structure may also map control channels in the FBMC and OFDM frames to common resource locations so that the respective control channels are aligned in the time and/or frequency domains. The unified frame structure may also share synchronization channels between FBMC and OFDM frames. Additionally, overhead in an FBMC time division duplexed (TDD) communications channel can be reduced by overlapping time windows appended to FBMC blocks.

Orthogonal frequency division multiplexed (OFDM) waveforms are presently used to communicate over Evolved Universal Terrestrial Radio Access (E-UTRA) air interfaces in fourth generation (4G) long term evolution (LTE) networks operating under the communications protocol defined by third generation partnership project (3GPP) technical standard (TS) 36.211 (2008), which is incorporated by reference herein as if reproduced in its entirety. OFDM waveforms provide many advantages over other waveforms, including the ease of implementation using fast Fourier transform (FFT) and inverse FFT (IFFT) and robustness against multi-path fading. However, OFDM waveforms also exhibit reduced spectral efficiency due to their inclusion of cyclic-prefix (CP) and the need for frequency guard bands. As such, other waveforms may be adopted into next generation wireless communication protocols.

Frame structure for filter bank multi-carrier (FBMC) waveforms


The invention relates to a process for condensing at least one epoxide on at least one cyclic anhydride of a dicarboxylic acid in the presence of a catalyst consisting of at least one titanium peroxidic complex of the peroxo type of the A form ##STR1## Said process allows to obtain a perfectly alternate polyester.

The condensation between an epoxide or an epoxide derivative and a cyclic anhydride has given rise to numerous works which have for example been summarized by LUSTON and VASS (Advances in Polymer Sciences 1984, Vol. 56, p. 91 and following pages) or by ISHII and SAKAI (Ring opening polymerisation, p. 13 and following pages, published by K. C. FRISCH and S. REEGEN, MARCEL DEKKER 1969).
An examination of the cited works shows that the main problem posed by this type of condensation is the homopolymerisation of the epoxide which causes the obtaining of a sequent polyether-polyester or of polymer mixtures, particularly when Lewis acids (TiCl.sub.4, BF.sub.3, etc) are used as condensation catalysts. In order to overcome this drawback, it has been suggested in prior art to utilize anionic or coordination catalysts.
FISHER (Journal of Polymer Science 1960, Vol. 44, p. 155 and following pages) has shown that the use of a tertiary amine as a condensation catalyst of an anhydride on an epoxide allows to obtain an alternate condensation.
However, this type of catalyst is ineffective as far as maleic anhydride is concerned, probably because of the complex side reactions with the amines at the level of the double maleic bond. Other types of anionic catalysts such as alkali metal salts or tetra-alkylammonium salts have also been utilized. For example WADILL, MILLIGAN and PEPPEL (Industrial and Engineering Chemistry, Product Research and Development 1964, Vol. 3, Part 1, p. 53 and following pages) describe the use of lithium chloride in the presence of protonic materials at 150.degree. C. These authors suggest that the homopolymerisation of epoxide is part of their process. As an example of a coordination catalyst, the dialkylzinc mentioned by INOUE et al. (Makromolekulare Chemie 1969, Vol. 126, p. 250 and following pages) can be cited; this type of catalyst can actually only be applied, according to INOUE et al., to phthalic anhydride. U.S. Pat. No. 4,565,845 describes the use of a catalytic system comprising an aluminium porphyrin which allows to obtain a polyester with a rather good alternation between the unit from the anhydride and that from the epoxide.
Transition metal-based catalysts have also been previously described. Thus, FISCHER (cited above) observes a partial homopolymerisation of the glycidic epoxide during its polycondensation with the phthalic anhydride in the presence of tetrabutyl titanate.
U.S. Pat. No. 3,546,176 claims the use of tetrabutyl titanate for producing unsaturated polyesters from anhydrides of unsaturated acids and from epoxides. However, as confirmed by a test carried out by the applicant and described hereafter, this catalyst does not allow to obtain a good alternation of the units from the anhydride and from the epoxide.

Process for condensing at least one epoxide on at least one cyclic anhydride in the presence of a titanium-based catalyst

L'Air Liquide Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude


An EGR valve includes an aluminum valve body, an outer metal ring, an inner resin ring, a butterfly valve, and a seal ring. The valve body includes a gas passage therein. The gas passage is part of an EGR passage, through which EGR gas is returned from an exhaust passage to intake passage of an engine. The outer ring has a cylindrical shape, and is fixed and disposed on an inner wall of the gas passage. The inner ring has a cylindrical shape, and is disposed on an inner peripheral wall of the outer ring. The butterfly valve opens or closes an inside of the inner ring, and includes a seal fitting groove at an outer peripheral edge of the butterfly valve. The seal ring is fitted into the groove, and seals a clearance between the butterfly valve and the inner ring when the butterfly valve is closed.

An engine disposed in a vehicle includes an exhaust gas recirculation system (EGR system) for returning EGR gas to its air intake side. The EGR system includes an EGR passage for guiding EGR gas from an exhaust passage of the engine to an intake passage; an EGR valve that regulates the amount of EGR gas in this EGR passage returned to the air intake side through the regulation of its opening degree; and an engine control unit (ECU) that performs control of the opening degree of this EGR valve (specifically, control of energization of an electric actuator disposed in the EGR valve).
A main feature of an EGR valve of a conventional technology will be described in reference to FIG. 4. In an EGR valve 101, a butterfly valve 106 (valving element having generally a shape of a disk) is arranged to be inclined relative to a shaft 110, and a seal ring 108 which prevents leakage at the time of valve closing is provided at an outer peripheral edge of the butterfly valve 106. The inside of a gas passage 102 is under a severe environment where the EGR gas flows and strongly-acid condensed water is thereby produced. For this reason, the seal ring 108 is formed from metal such as stainless steel which is excellent in acid resistance.
If a member in contact with the seal ring 108 is an aluminum material, from which a valve body 103 is made, a position of the valve body 103 in contact with the seal ring 108 is immediately corroded and worn out. Accordingly, in the previously proposed EGR valve 101, a bore ring (cylindrical nozzle) 9 made of stainless steel is disposed at the region in contact with the seal ring 108 so as to limit corrosion and wear of the region in sliding contact with the seal ring 108 (see, for example, JP-A-2007-285311).
In this manner, in the conventional EGR valve 101, every time the butterfly valve 106 is opened and closed, the seal ring 108 made of stainless steel and the bore ring 109 made of stainless steel are rubbed against each other. However, although the rubbing of stainless steels on each other limits their wear rather than rubbing between stainless steel and aluminum, two stainless steels are not a combination excellent in wear resistance.
Therefore, in the previously proposed EGR valve 101 in which the seal ring 108 made of stainless steel and the bore ring 109 made of stainless steel are rubbed against each other, there is concern that wear is caused due to its long-term use and EGR gas may leak from the worn-out region. If EGR gas leaks out of the worn-out region at the time of closing the EGR valve 101, the specified amount of fresh air (amount of air required by an ECU) cannot be ensured. As a result, there is concern about a defect such as reduction of engine output or an engine failure.


In a four-wheel drive motor vehicle in which an engine and a transmission are in parallel with each other, the transmission is arranged at the rear of the rearwardly inclined engine, and a front-wheel drive shaft is disposed under the transmission. A bevel gear of a transfer device is arranged in a space before the drive shaft and under the engine. The rear part of a drive pinion engaging with the bevel gear is connected to a propeller shaft. An exhaust pipe is connected to a rear part of the engine, and a steering shaft extending in a car width direction is disposed under the exhaust pipe. A connecting part for connecting the transfer device and the propeller shaft is located at the front of the steering shaft. Accordingly, the bevel gear is positioned appropriately when transmitting a drive power from the transfer device to the propeller shaft, and the power train is easily assembled into an engine compartment of the vehicle.

This invention relates to a power train construction of a vehicle.
As a conventional power train construction, there is known a technique disclosed in, for example, Laid Open Unexamined German Patent Application No. 3,838,073, in which an engine and a transmission are disposed parallel to one another in a direction of movement of a vehicle in such a manner that an axial line of a crankshaft of the engine is in a car width direction of the vehicle, the transmission is arranged at the rear of the engine, and an axis of the transmission is in parallel with the crankshaft of the engine. In this prior art reference, a front axle of the vehicle is located under the transmission, the engine is inclined in a rearward direction of the vehicle, and a driving power transmitted from the engine to the transmission is transmitted to rear wheels from a propeller shaft extending in the vehicle movement direction or longitudinal direction of the vehicle through the medium of a transfer device having a bevel gear for changing a transmitted direction of the driving power by 90.degree.. As to an exhaust system of the engine, arranged on a rear side of the engine is an exhaust port which is connected to an exhaust pipe extending obliquely, downwardly in a rearward direction of the vehicle.
On the other hand, in general, front wheels are steered in such a manner that rotation of a steering wheel in a compartment is transmitted to right and left front wheels via a steering shaft disposed widthwise of the vehicle.
In the power train construction of the above-noted reference, however, since the engine is inclined in a rearward direction of the vehicle, a ground clearance of the vehicle where the steering shaft is disposed is lowered. Particularly, in a power train construction where the exhaust pipe is connected to the exhaust port located on the rear side of the engine, since the exhaust pipe occupies a space behind the engine, a ground clearance of the steering shaft is further lowered, so as to be the same ground clearance of the axis of the front wheels. Consequently, when the transfer device is disposed under the steering shaft, the lowest ground clearance of the vehicle cannot be ensured because a lower part of the bevel gear having a large diameter extrudes downward. On the other hand, in a power train construction where the transfer device is disposed at the rear of the steering shaft, the whole power train including the transfer device lies along the longitudinal direction of the vehicle, which causes no compaction of the power train in the longitudinal direction. Further, when an upstream portion of the exhaust pipe is connected to the rear side of the engine, the whole power train including the exhaust pipe on the upstream side and the transfer device is extruded at upper and lower parts thereof rearward of the vehicle and is hollowed at an intermediate part thereof. As a result, when the whole power train is assembled by lowering the power train from above to an engine compartment of the vehicle at one time, to a set position of the engine compartment of the vehicle in which the steering shaft is already assembled, the steering shaft blocks the assembling, which results in difficult assembling of the power train within the engine compartment.


A socket for an electrical part comprises a socket body and a contact pin through which an electrical part having a terminal and a printed circuit board are electrically connected. The socket body is provided with a lower plate to be mounted to the printed circuit board and an upper plate which is disposed above the lower plate and on which the electrical part is mounted. The upper plate is exchanged with one having a seating portion of different height. A contact portion of the contact pin is also exchangeable with one having different shape or type.

1. Field of the Invention
The present invention relates to a socket for electrical parts for detachably accommodating and holding an electrical part such as a semiconductor device (called as xe2x80x9cIC packagexe2x80x9d hereinafter), and more particularly, relates to a socket for electrical parts having elements or parts commonly utilized for different electrical parts.
2. Prior Art of the Invention
In known art, there have been provided IC sockets, as xe2x80x9csocket for electrical partsxe2x80x9d mentioned above, for carrying out performance tests of IC packages as xe2x80x9celectrical partxe2x80x9d.
In such IC socket, a number of contact pins are arranged on a socket body and, in use, the socket body is mounted on a printed circuit board with the IC package being mounted on the socket body. In this state, the contact pins contact terminals of the IC package to thereby establish an electrical connection between the IC socket and the printed circuit board.
In such prior art as mentioned above, however, the IC packages include various types or kinds such as LGA (Land Grid Array), BGA (Ball Grid Array) and PGA (Pin Grid Array), which have different shapes of terminals. Accordingly, it has been required to change the entire of the IC socket when a different type of IC package is used and handled, thus being inconvenient and not economical.
An object of the present invention is to substantially eliminate defects or inconveniences encountered in the prior art mentioned above and to provide a socket for electrical parts having elements or parts commonly utilized for electrical parts, even if kinds or types thereof are different, without exchanging the entire structure of the socket.
This and other objects can be achieved according to the present invention by providing a socket for an electrical part comprising: a socket body; and a contact pin which is provided for the socket body and through which an electrical part having a terminal and a printed circuit board are electrically connected, in which the socket body has a lower plate to be mounted to the printed circuit board and an upper plate which is disposed above the lower plate and on which the electrical part is mounted, wherein the upper plate has a seating portion on which the electrical part is placed in a contacting manner, and the upper plate is exchanged with another one having a seating portion of different height.
According to this aspect, since the upper plates having the seating portions of different heights can be selected and exchanged in accordance with kinds or types of the electrical parts to be used, the lower plate can be commonly utilized while maintaining the contacting pressure between the terminal of the electrical part and the contact pin.
Another preferred aspect of the present inventions is that the contact pin is exchangeable for another one having a different contact shape in accordance with a shape of a terminal of the electrical part.
According to the foregoing aspect of the present invention, the conductive performances between the contact portions of the contact pins and the terminals of the electrical part can be improved.
Another aspect of the present invention is that the contact pin comprises a first plunger electrically connected to the terminal of the electrical part, a second plunger electrically connected to the printed circuit board, a tubular member disposed between the first and second plungers and an elastic member disposed therebetween, the tubular member having one end abutting against one of the first and second plungers and another end slidably contacting other one of the first and second plungers, the elastic member having an urging force for urging the first and second plungers in directions apart from each other, and the first plunger is exchangeable for another one having a different contact shape in accordance with a shape of the terminal of the electrical part.
According to the foregoing aspect of the present invention, the first plungers of the contact pin is exchangeable so that the conductive performance can be also improved with other many parts or elements being common.
Still another aspect of the present invention is that the lower plate is formed with a plurality of lower side through holes into which the second plunger can be inserted, the low side through holes being formed in an arrangement range wider than that of an upper side through holes.
According to the foregoing aspect of the present invention, the socket can be used for an electrical part having different size or shape, or having different number of terminals.
The contact portion may have a mount shape to which a terminal having a land shape contacts. The contact portion may have a V-shaped groove to which a terminal having a solder ball shape or round shape contacts.
According to the foregoing aspect of the present invention, the contact portion of the V-shaped groove makes it possible to avoid damage at the lowest portion of the terminals having round shape. The contact portion may have a plural mount-shape to which a terminal having a pin (rod) shape contacts.
The elastic member is a coil spring disposed inside the tubular member.
The upper plate is provided with the upper plate body, to which the plurality of upper side through holes are formed and on which the electrical part is mounted, and provided with a guide portion for guiding a peripheral edge portion of the electrical part. The guide portion may be formed to be detachable from the upper plate body.
According to the foregoing aspect of the present invention, by exchanging the guide portion for another one, another electrical part having a different size may be utilized.
The nature and further characteristic features of the present invention will be made more clear from the following descriptions made with reference to the accompanying drawings.

Socket for electrical parts having separable plunger


There is described a drilling fluid for wellbore strengthening having nanoparticles and granular particles. In one aspect described herein, the drilling fluid is an invert emulsion based fluid. In a further aspect, the nanoparticles are iron hydroxide or calcium carbonate, and in a further aspect from about 1 to 30 nm in size. In one aspect described herein, the granular particles are graphite or calcium carbonate and in a further aspect, up to 250 μm in size. The nanoparticles and granular particles plug fractures in the wellbore to strengthen the wellbore.

Hydrocarbons, such as oil and gas, are recovered from underground formations through drilled wells. The success of any well drilling operation depends on many factors and one of the most important is the drilling fluid. Drilling fluids, also called drilling muds, are circulated from the surface through the drill string and introduced to the bottom of the borehole as fluid spray out of drill bit nozzles and subsequently circulated back to the surface via the annulus between the drill string and the well hole. Drilling fluids are formulated to cool down and lubricate the drill bit, remove cuttings from the hole, prevent formation damage, suspend cuttings and weighting materials when circulation is stopped, and cake off the permeable formation by retarding the passage of fluid into the formation.
Drilling operations face great technical challenges with drilling fluid loss being the most notable. Fluid loss is also an issue for other well fluids such as kill fluids, completion fluids and stimulation fluids. Drilling fluid loss is the partial or complete loss of fluid to the formation during drilling. Loss of fluid causes several severe consequences to the drilling operations. Loss of fluid, in turn, impacts the cost of drilling. Therefore, drilling and other well fluids are typically formulated with loss circulation materials or additives (LCM). The primary function of LCM is to plug the zone of loss in the formation, away from the borehole face so that subsequent operation will not suffer additional fluid losses. LCM forms a barrier which limits the amount of drilling fluid penetrating the formation and prevents loss.
Lost circulation is the leading cause of non-productive time on an oil rig1 or drilling site. This is a particular problem while drilling with a narrow mud weight window, for example in depleted reservoirs. Mud weight required for well control and to maintain a stable wellbore generally exceeds the fracture resistance of a formation. Casing strings are designed at different stages of the well so that the well can be drilled where the mud weight window is balanced between the pore and fracture pressure with depth. This boundary value also typically includes a safety of trip tolerance added to the pore pressure and subtracted from the fracture pressure.
A drilling fluid that effectively increases the fracture pressure tolerance gradient strengthens the wellbore and increases the fracture gradient. The result of this effect is that the drilling design of a well might require one or more less drill string casings/hole sizes which highly affects the drilling and completion economics of a well. As an example, a three different hole size casing program with surface, intermediate and main hole casing can, with these new fluids, be designed with only one surface and one main borehole casing which could then have a larger hole size in the production zone and produce at higher rates as well. This is also called a mono-bore oil and gas wellbore. The more casing sizes run on a well, the higher the potential is to reduce the number of strings and save money.
In a depleted reservoir, there is a drop in pore pressure as the reserves decline which weakens the hydrocarbon-bearing rocks but neighboring low permeability rocks such as shale may maintain their pore pressure. The result is that the mud weight required to support the shale exceeds the fracture resistance of the sands and silts. This leads to severe mud losses that prevent drilling ahead and creates the possibility of sticking the bottom hole assembly, drill pipe or liner/casing.
There are different technologies for dealing with this problem but preventive wellbore strengthening technologies are preferred. Wellbore strengthening increases the resistance of formations to circulation loss during drilling operations. By strengthening the wellbore, the width of the operating mud window is increased or the gap between the pore pressure and fracture gradient in the formation is widened. Wellbore strengthening may also prevent loss circulation, wellbore instability, stuck pipe, differential sticking, kick and blow out, excessive number of casings run and cutting removal issues.
One focus for strengthening wellbores is the properties of the solid contents of the drilling fluids since they play a key role in the process. LCM has been added to drilling fluids to successfully strengthen wellbores. This was achieved by widening fractures and effectively plugging them with the right sized particle LCM. This isolates the fracture tip from the fluid pressure which then controls the fracture propagation and ultimately increases the hoop stress around the wellbore.2-8 The result is that the fracture pressure is increased. This allows an operator to use a drilling mud with a higher mud weight through the strengthened wellbore to access other sections of the formation.
It was previously thought that LCM's would only plug fractures and strengthen wellbores in permeable formations. LCM's were not effective in impermeable formations. Also small particles that only plugged the pore throat would not effectively plug a fracture and seal the formation. Leak off of the base fluid was required.6 Nanoparticles were very effective at plugging pore throats but were not thought to be effective in strengthening wellbores. Nanoparticles have very different properties as compared to its parent material.10
Nanoparticles have been used in well fluids for a number of purposes.
U.S. Pat. No. 3,622,513 (1971) is directed to oil-based drilling fluids with improved plastering properties and reduced fluid loss properties at extreme conditions of borehole temperature and pressure. The drilling fluids contain asphaltous material and a weighting agent, usually barium sulfate having a particle size of 100 to 200 μm, which primarily result in the formation of the filter cake to prevent fluid loss to the formation. The drilling fluids also contain a small amount of a secondary weighting material inert to the fluid and having a particle size of less than 3 μm. The fluids showed some reduction in fluid loss. However, the compositions required extra additives, such as the asphalt material, which bind to the nanoparticles and acted as a filler or plaster between the particles at high temperature to reduce the fluid loss. The fluid may also contain other lost circulation additives.
U.S. Pat. No. 6,579,832 (2003) is directed to a method of rapidly adjusting the fluid density of drilling fluids using superparamagnetic nanoparticles. The particles were effective to change the density state of the fluid required to control subsurface pressures, and to preserve and protect the drilled hole until a casing is run and cemented. The nanoparticles were sized between 0.5 and 200 nm and formed into clusters having an average size of between 0.1 and 500 μm. The clusters were formed by incorporating the nanoparticles into a matrix of glass or ceramic. Group VIII metals Cd, Au and their alloys were found to provide an excellent result in adjusting fluid density in a reversible manner. 90% of the supermagnetic nanoparticles from the treated drilling fluid from the downhole location were recovered by a magnetic field at the surface resulting in the adjustment of drilling fluid density within a short period of time and circulation of the magnetic nanoparticles to the surface level for reuse in the drilling fluid.
U.S. Patent Application 2009/314549 (2009) considered compounds for reducing the permeability of shale formations using specific nanoparticles in the drilling fluids. By identifying the pore throat radii of shale samples, fine particles were selected that would fit into the pore throats during the drilling process and create a non-permeable shale surface. The drilling mud was a water-based mud with nanoparticles having a size range of 1-500 nm selected from silica, iron, aluminum, titanium or other metal oxides and hydroxides and also composed of a surface active agent. The aqueous well-drilling fluid contained between about 5 to 50 weight percent, based on the weight of the aqueous phase and resulted in a reduction in permeability of the shale, which resulted in drastic reduction of absorbed water and potential for collapse. The minimum concentration required to reduce the fluid penetration was 10 wt % nanoparticles and in some cases, required high concentrations of nanoparticles of 41 wt %.
Aqueous-based drilling fluids generally require a higher concentration of nanoparticles than other types of drilling fluids. They also require additional additives such as surfactants to stabilize the nanoparticles in the fluid system whereas other based fluids, such as invert emulsion drilling fluids, do not need to include other additives to completely disperse the nanoparticles. Nanoparticles that have a hydroxyl group tend to agglomerate faster in aqueous based fluids. This agglomeration causes poor dispersions and the addition of surfactants reduces this problem. Poor dispersion in turn causes fluid loss even after the addition of the nanoparticles. As well, flocculated or poorly dispersed suspensions form more voluminous sediments. The resulting filter cake is not as dense and impenetrable as compared to that formed from a stable suspension. Therefore, the use of nanoparticles in aqueous based fluids teaches little about its use in non-aqueous-based fluids such as invert emulsions.
A related publication is "Use of Nanoparticles for Maintaining Shale Stability" Sensoy (2009). It also discloses the use of nanoparticles in an aqueous drilling fluid for nanopore throat reduction. It found that the 5 wt % of nanoparticles in the fluid was less effective and the minimum level of nanoparticles was at least 10 wt %. It also tested higher levels of 29 wt % and 41 wt %. The paper concludes that higher amounts of nanoparticles were preferable to achieve the nanopore throat reduction.
U.S. Patent Application 2011/59871 (2010) relates to a drilling fluid including graphene and chemically converted nanoplatelet graphenes with functional groups. The graphene comprised about 0.001% to about 10 vol % of the drilling fluid. The functionalized chemically-converted graphene sheets were about 1.8 to about 2.2 nm in thickness. Whatman 50 allowed some graphene oxide to pass through the filter. Nanoparticles pass through the filter paper along with the filtrate which may block the interporosity of rock and create formation damage. This may result in permeability impairment and thus lead to a reduction in oil and gas production.
U.S. Patent Application 2009/82230 (2009) relates to an aqueous-based well treatment fluid, including drilling fluids, containing a viscosifying additive. The additive has calcium carbonate nanoparticles with a median particle size of less than or equal to 1 μm. The amount of calcium carbonate nanoparticles used in the drilling fluid was approximately 20 wt %. The nanoparticles used in the well treatment fluid were capable of being suspended in the fluid without the aid of a polymeric viscosifying agent. The addition of the nanoparticles altered the viscosity of the fluid. Nanoparticles suspended in a well treatment fluid even at high temperature as 350° F. typically exhibit sag (inadequate suspension properties) particularly at high temperatures of around 350° F. The viscosity changes of a fluid upon addition of nanoparticles were well reported.
U.S. Patent 2011/162845 discloses a method of servicing a wellbore. It introduces a lost circulation composition into a lost circulation zone to reduce the loss of fluid into the formation. The lost circulation composition comprised Portland cement in an amount of about 10 wt % to about 20 wt % (of the lost circulation composition), nanoparticles and in particular nano-silica in an amount of about 0.5 wt % to about 4 wt % and having a particle size of about 1 to about 100 nm, amorphous silica in an amount of about 5 wt % to about 10 wt %, synthetic clay in an amount of about 0.5 wt % to about 2 wt %, sub-micron sized calcium carbonate in an amount of about 15 wt % to about 50 wt % and water in an amount of about 60 wt % to about 75 wt %. Loss circulation additives are formed with a mix of nanocomponents and cement to reduce the setting time for mud cake formation and development of gel strength. However, high amounts of the nanoparticles are required with the cement to develop the mud cake formation and gel strength.
By virtue of their very small sizes, nanoparticles (NPs) have the potential of acting as effective lubricant additives. Their size and shape enable them to enter contact zones between surfaces easily. Inorganic nanoparticles mostly do not display any affinity to oil and may not be affected by the mud type. In-situ and ex-situ techniques for forming a wide variety of well dispersed NPs in an invert emulsion as well as water-based drilling fluid have been detailed in the art (Husein et al., 2012). These methods rely heavily on high shearing, which produces finely dispersed water pools, in the case of invert emulsion drilling fluids, and the use of these water pools as nanoreactors to form NPs with sizes mainly below 100 nm. Once formed, these NPs display very high stability in the mother drilling fluid and interact very effectively with the rest of the drilling fluid (Husein et al., 2012). Previous experiments showed that these particles perfectly seal filter cakes by creating crack-free, very smooth surfaces (Husein et al., 2012). Therefore, these particles contribute to the formation of slippery layers between the borehole and the drill string leading to lower overall friction coefficient and, subsequently, increase the extended reach of horizontal drilling. Moreover, due to the small sizes of these particles, the wear and tear of down hole equipment and tools becomes negligible as less kinetic energy (nano sized particles achieve lower sedimentation speed compare to the large sized particles) and abrasive action is encountered. Overall, the application of nanoparticles in drilling fluid presents a good potential for reducing friction while drilling and, hence, improve the extended reach.
Other references, such as Amanullah et al. 2011, consider the use of small amounts of nanoparticles in water and indicate the potential for beneficial effects on differential sticking, torque reduction and reduction of drag problems in certain types of drilling. However, these references experiment with nanoparticles in water and require very active stabilizers to maintain the nanoparticle dispersions or look at the interaction of nanoparticles with other components that may be present in a well fluid. The references do not provide data directly relevant to results in industrial drilling fluids but merely indicate further areas for research.
There is therefore a need for an additive for drilling fluids to more effectively strengthen the wellbore during drilling. This is achieved by plugging fractures with nanoparticles and granular particles present in the fluid in low amounts.

Drilling fluids with nano and granular particles and their use for wellbore strengthening


A roller for a conveyor system is comprised of a body portion that is generally cylindrical and rotatable about a central axis. A first bearing surface is defined around the body portion. A second bearing surface is raised above the first bearing surface and is generally concentric to the first bearing surface, the second bearing surface being more resilient than the first bearing surface.

The present invention relates to a conveyor system and roller assembly that is particularly applicable for use in a multi-chamber washer and shall be described with reference thereto. It being understood, however, that a conveyor system or roller assembly according to the present invention may find advantageous application in other applications.
A multi-chamber washer is generally comprised of several different chambers that are aligned side-by-side. Each chamber has a specific purpose, such as washing, rinsing, or drying a load.
Objects washed within a multi-chamber washer are typically contained within an open basket or tray. A conveyor system is provided within the washer to move the basket or tray from one chamber to another. The conveyor system typically extends through the adjacent chambers within the washer to convey a basket or rack to the respective chambers.
Conveyor systems comprised of driven rollers have been used to convey the baskets or trays through a multi-chamber washer. One problem with such conveyor systems is maintaining a sufficient driving force between the baskets and the rollers. In this respect, different types of baskets may be used within the multi-chamber washers. Baskets having a base formed of plastic materials are often used in such washers to reduce noise during the conveying, i.e., indexing, of the baskets. Plastic material also makes it easier to control the friction coefficient between the baskets and the drive rollers. Other manufacturers form baskets of stainless steel material. Stainless steel racks are more easily cleaned during the washing process and are able to heat more quickly because of the higher coefficient of thermal conduction.
It is also known to form the conveyor rollers of a plastic or metal material. As indicated above, rollers formed of plastic material can provide a better coefficient of friction between the roller and the basket and, likewise, help reduce noise during the conveying, indexing process. However, as noted above, plastic rollers are more difficult to clean, as compared to metal rollers. Metal conveyor rollers are preferred because of the ability to clean such rollers during the washing process, as well as their durability. However, maintaining adequate driving force between a metal roller and a metal frame of a basket can be difficult, particularly in wet environments that would be encountered within the washer. Similarly, the friction coefficient between a metal roller and a metal basket will vary depending upon the weight of the basket and the articles therein.
The present invention overcomes these and other problems and provides a roller assembly for a conveyor system having improved frictional, driving characteristics.


Disclosed are a novel amino anthracene derivative and an organic electro-luminescence device using the same. More specifically, the disclosed amino anthracene derivative has a core (e.g., indenoanthracene core) of an anthracene moiety (with a high device characteristic) linked to a fluorene moiety (with a high fluorescence characteristic), in which in the core is substituted with at least one amine group represented by Formula 2 and the disclosed organic electro-luminescence device uses the amino anthracene derivative as a light emitting layer material so as to be enhanced in efficiency, operating voltage, and life span.

In general, an organic light emitting phenomenon indicates conversion of electric energy into light energy by means of an organic material. An organic electro-luminescence device using the organic light emitting phenomenon generally has a structure including an anode, a cathode, and an organic material layer interposed therebetween. Herein, in many cases, the organic material layer may have a multi-layered structure having respective different materials in order to improve efficiency and stability of an organic light emitting device. For example, it may include a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and the like.
When such an organic electro-luminescence device is applied with a forward voltage, holes and electrons are injected from an anode and a cathode, respectively. Then, the holes and the electrons recombine in a light emitting layer, thereby forming excitons (electron-hole pairs). When the excitons are converted from an excited state of pi-electrons per molecule to a ground state, the corresponding energy is converted into light. In order to enhance the color purity and efficiency of emitted light, there has been recently known a method for doping a small amount of a fluorescent or phosphorescent pigment into the light emitting layer forming excitons. The method is based on the principle that if a small amount of a fluorescent or phosphorescent pigment (hereinafter, referred to as a dopant) having a smaller energy band gap than molecules forming a light emitting layer is mixed with the light emitting layer, excitons which are generated in the light emitting layer are transported to the dopant, thus emitting a light having a high efficiency.
Various materials emitting green light, such as 8-hydroquinoline aluminum salt, have been conventionally used as a host. However, there are some problems to be improved in view of luminous efficiency and life span.

Aminoanthracene derivative and an organic electroluminescent element employing the same


A method of degassing a coating liquid, comprising the step of:                irradiating the coating liquid with a plurality of ultrasonic waves of different frequency bands simultaneously to degass said coating liquid.

1. Field of the Invention
The present invention relates to a method and apparatus for degassing a coating liquid, and in particular, to a method and apparatus for degassing a coating liquid, which is suitable for degassing a photosensitive material coating liquid, a heat development photosensitive material coating liquid, a transparent heat-sensitive material coating liquid, an organic solvent coating liquid, or the like.
2. Description of the Related Art
In general, in a coating liquid used to coat a support with various liquids, air bubbles are likely to be generated during an operation such as agitation, dispersion, or dispensation which is performed before a coating step. When the coating liquid containing air bubbles is supplied to a coating apparatus, then coated on a support using the apparatus, and dried, bubble defects such as bubble traces or pin holes are likely to occur in the coat film. Consequently, a good and uniform coat film cannot be formed. Therefore, a sufficient degassing process must be executed before the coating step. As a degassing method employed for such a purpose, the use of ultrasonic waves is well known. A large number of proposals for this technique have been made (Japanese Patent Application Publication Nos. 1984-92003, 1988-178807, 1993-92103, 1994-130547, 1996-318102, 1999-262601, 1999-197406, and 1999-290611).
Japanese Patent Application Publication No. 1984-92003 is a proposal that improves the arrangement of ultrasonic vibrators. Japanese Patent Application Publication No. 1988-178807 is a proposal that dissolved air be removed before irradiation with ultrasonic waves. Japanese Patent Application Publication No. 1993-92103 is a proposal that improves the configuration of an ultrasonic degassing apparatus. Japanese Patent Application Publication No. 1994-130547 is a proposal that a vacuum pump be used to reduce pressure before irradiation with ultrasonic waves and that a pressurization pump be used to increase the pressure after the irradiation with ultrasonic waves. Japanese Patent Application Publication No. 1996-318102 is a proposal that is a combination of reduced pressure ultrasonic degassing, pressurized ultrasonic degassing, and management of a liquid temperature. Japanese Patent Application Publication No. 1999-262601 is a proposal that is a combination of a plurality of degassing steps each combined with irradiation with ultrasonic waves. Japanese Patent Application Publication No. 1999-197406 that two degassing baths are provided in series having different conditions for irradiation with ultrasonic waves. Japanese Patent Application Publication No. 1999-290611 is a proposal that the oscillation frequency of ultrasonic waves is continuously modulated to attenuate or eliminate a standing wave to facilitate degassing.
However, there remain problems that cannot be solved by the various proposals using ultrasonic waves. The problems are as follows.
1) The air bubbles in the coating liquid cannot be sufficiently removed.
2) The gas dissolved in the coating liquid is precipitated to form air bubbles again.
3) The coating liquid is damaged or piping through which the coating liquid is transferred is corroded.
4) Ultrasonic waves applied must be optimized in accordance with the composition of the coating liquid or a degassing speed.
5) A combination of supersonic waves with another degassing method results in an increase in the size of the apparatus.
These problems will be described below. First, the problem 1) will be described.
A coating liquid such as a photographic sensitive coating liquid which contains various additives is originally likely to become frothy and is prone to contain air bubbles. Further, in recent years, with improvements in coating methods and productivity, there has been an increase in the viscosity of the coating liquid and in degassing throughput per unit time. Accordingly, although various degassing methods and apparatuses have been proposed, these conventional methods still have an insufficient degassing capability.
One of the reasons for the insufficient degassing capability is that when a liquid accommodated in a degassing container is irradiated with ultrasonic waves at a fixed oscillation frequency, ultrasonic vibration causes a fixed compressional wave to be formed. Thus, a standing wave is generated. The standing wave creates problems; air bubbles in the liquid are trapped in a particular area to prevent the bubbles from floating, or the standing wave degrades the capability of dissolving and eliminating fine air bubbles. As a result, air bubbles cannot be removed effectively.
To solve this problem, for example, Japanese Patent Application Publication Nos. 1984-92003, 1993-92103, and 1999-197406 propose configurations in which a plurality of ultrasonic vibrators are arranged on the bottom and sides of a degassing container and opposite one another. In this configuration, ultrasonic waves applied by the individual ultrasonic vibrators are complementary to one another. However, these configurations can increase the quantity of ultrasonic waves applied per unit area of the degassing container to improve degassing efficiency, but fail to eliminate the standing wave. It is thus difficult for these proposals to efficiently and perfectly remove air bubbles from the liquid.
To solve this problem, Japanese Patent Application Publication No. 1999-290611 and the like propose that the oscillation frequency of ultrasonic waves applied is continuously modulated over a predetermined frequency bandwidth around a frequency used as a reference to periodically continuously vary the distribution of sound pressure of ultrasonic waves applied to a coating liquid. This configuration has substantially solved the problem that bubbles in the coating liquid cannot be sufficiently removed. However, the degassing achieved by this configuration may be insufficient depending on the physical properties of the liquid and a degassing process speed per unit time. Specifically, The output of ultrasonic waves for each physical property of the liquid must be individually set in view of the degassing process speed per unit time.
Now, the problem 2) will be described. In the conventional ultrasonic degassing apparatus, a coating liquid is accommodated in the degassing bath and then irradiated with ultrasonic waves. When this apparatus is used to irradiate the coating liquid with ultrasonic waves, the pressure of the coating liquid varies to facilitate the dissolution of air bubbles in the liquid under pressure. This effect is further enhanced by increasing the output of ultrasonic waves. However, an excessive increase in the output of ultrasonic waves causes fine air bubbles of negative pressure, that is, cavitation to be instantaneously generated in the liquid and then disappear. When the cavitation disappears, a local reaction field estimated to have a pressure of 87,000 atm and a temperature of 160,000° C. is instantaneously formed to precipitate a gas again which has been dissolved in the surrounding liquid. This phenomenon is likely to occur if the output of ultrasonic waves is excessively increased and if the degassing process speed per unit area is low.
Now, the problem 3) will be described. In the conventional ultrasonic degassing apparatus, as already described, when the cavitation disappears, a shock wave is generated which instantaneously forms a local reaction field estimated to have a pressure of 87,000 atm and a temperature of 160,000° C. Thus, the coating liquid may be damaged or piping through which the coating liquid is transferred may be corroded.
Now, the problem 4) will be described. In the conventional ultrasonic degassing apparatus, bubbles are likely to precipitate in the case of insufficient degassing and an excessive increase in the output of ultrasonic waves. To deal with this, for example, Japanese Patent Application Publication No. 1999-197406 and No. 1999-290611 and the like propose the following configurations: the one that externally transmits one or more frequency variation cycles of ultrasonic vibration to the coating liquid in a reservoir or transfer pipe; in a frequency variation cycle, vibration varies from a low frequency to a high frequency, and the one that continuously modulates the oscillation frequency of ultrasonic waves applied, over a predetermined frequency bandwidth around a frequency used as a reference to periodically continuously vary the distribution of sound pressure of ultrasonic waves applied to the coating liquid. An ultrasonic degassing system with this frequency modulating system has significantly reduced the insufficiency of degassing. However, the degassing may still be insufficient depending on the physical properties of the liquid and the degassing process speed per unit time. Thus, disadvantageously, the output of ultrasonic waves for each physical property of the liquid must be individually set in view of the degassing process speed per unit time.
Now, the problem 5) will be described. Japanese Patent Application Publication No. 1999-130547, No. 1996-318102 and No. 1999-262601 and the like propose configurations having a plurality of degassing steps obtained by combining the ultrasonic degassing method with other degassing methods. For example, according to Japanese Patent Application Publication No. 1994-130547, a coating liquid is guided to a predetermined degassing container, and the pressure of the coating liquid is reduced to float and remove air bubbles. Then, the interior of the same degassing container is pressurized, which the coating liquid is irradiated with ultrasonic waves. Consequently, air bubbles are dissolved in the coating liquid. This method has a certain degassing capability. However, since the same container must undergo a plurality of steps, the degassing process requires a long time. Further, disadvantageously, the size of the apparatus must be increased.

Method and apparatus for degassing coating liquid


A method of generating photomask data for fabricating a microlens array, the photomask having a microlens pattern including light-shielding portions and non-light-shielding portions, a rectangular region including a surrounding region having four sides of the rectangular region as outer edges and a primary region having boundaries that are inner edges of the surrounding region, the surrounding region being configured by four strip regions each including one of the four sides as its part, and a width between each outer edge and each corresponding inner edge being not more than 1/2 of a wavelength of exposure light. The method includes determining a layout of light-shielding portions and non-light-shielding portions in the surrounding region so that a density of light-shielding portions is set to fall within a range from 0% to 15%.

1. Field of the Invention
The present invention relates to a method of generating photomask data, a method of fabricating a photomask, a memory medium storing programs for generating photomask data, a method of manufacturing a solid-state image sensor and a method of manufacturing a microlens array.
2. Description of the Related Art
A solid-state image sensor has microlenses that are used to enhance focusing efficiency on light-receiving units (photoelectric converters). Japanese Patent Laid-Open No. 2004-145319 discloses a method of forming microlenses by exposing and developing a photosensitive lens material layer using a photomask which can control amounts of transmitting light by a micro-dot pattern arrangement.

Method of generating photomask data, method of fabricating photomask, non-transitory memory medium storing program for generating photomask data, method of manufacturing solid-state image sensor having microlens array and method of manufacturing microlens array


An apparatus and method for setting a role based on capability of a terminal are provided. The apparatus includes a calculation unit calculating a capability value of the terminal to check whether the role set in a pertinent terminal is suitable, a determination unit determining whether the role set on the pertinent terminal is suitable based on the calculated capability value, and a setting unit changing and managing information for setting the role set in the pertinent terminal.

1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to setting a role based on the capability of a terminal, and, more particularly, to an apparatus and a method of calculating a capability value according to a change in the capability of each terminal and changing a role of the terminal based on the calculated capability value of the terminal.
2. Description of the Related Art
A conventional algorithm, i.e., peer-to-peer (P2P), that is an application level protocol, such as hyper text transfer protocol (HTTP), supports real time communications, resource distribution, resource exchange, and others between computer users. P2P networks can be classified into hybrid P2P networks using a server, and pure P2P networks where every node serves as a server and a client. Pure P2P networks that are based on the fundamental concept of P2P cannot search for and find resources shared by nodes in a large-scale network. A hybrid P2P network shares resources with each of a plurality of nodes through the server, and comprises a central server providing services and P2P nodes having substantial sharing resources. The central server maintains a network connection session with each of the nodes, manages metadata for sharing resources, and easily searches for resources required by the P2P nodes. Each of the P2P nodes accesses the server to search for a node that holds resources in order to search for the sharing resources. A resource is actually exchanged between two connected nodes. Napster was one of the first widely used hybrid P2P networks. However, a hybrid P2P network has limited extensibility, is more costly, and is not stable due to centralization.
Examples of widely used pure P2P networks are Gnutella and Freenet. Gnutella forms a network by connecting each of a plurality of nodes in terms of applications. Each of the nodes floods a search message into a predetermined range to search for a file and obtains information of a node that holds the file. However, since each of the nodes floods a search message periodically into the Gnutella network, the pure P2P network has limited extensibility.
Meanwhile, a P2P overlay network that is constructed by the combination of an actual value and a key obtained from a hash function using a hash table provides extensibility and stability. Chord, Pastry, and CAN are protocols for P2P overlay networks based on a distributed hash table (DHT).
Chord uses an m-bit virtual identification space to assign nodes and sharing files in identification values obtained from a hash function. Also, each of the nodes maintains a routing table called a finger table to easily search for resources.
Microsoft's Pastry assigns uniformly distributed node identifications randomly from a circular 128-bit identification space through an encoding hash. Given a 128-bit key, Pastry routes an associated message toward a live node whose node identification is numerically closest to the key. Each node keeps track of its neighbor set and notifies applications of changes in the set.
CAN obtains a vector P (p=hash (key)) corresponding to a point in a d-dimensional space through the hash function. Each of the nodes stores data corresponding to a zone divided from a virtual space.
In addition, most structural P2P systems have planar structures and peers participating in the P2P systems perform the same role.
Recently, focusing on the fact that terminals participating in the overlay network system based on the DHT have different capabilities, various methods of allowing terminals to perform different roles based on terminal capability have been proposed, and peers are classified as supernodes and leaf nodes according to their roles. However, since the fact that node capability may change has not been taken into consideration, a supernode role assigned in the first place may turn out to be unsuitable later. Meanwhile, in the case where a leaf node role was assigned to a terminal in the first place and the capability of the terminal was increased later, the terminal could not fully utilize its capability due to the first assigned role as a leaf node. Therefore, the overall performance of the P2P system may be lowered.
Korean Published Patent Application No. 2004-0101050 (Method for Allocating Identifier Peer Group in Peer-to-Peer Network) discloses a technology for defining suitable parameters and an algorithm for automatically determining an identifier for a peer group while minimizing an amount of data traffic required for distributing new identifiers, the technology being used when the most suitable existing group identifier is determined and reused, or when the structure of an OwnerZone changes by adding or removing peers, and a new OwnerZone is generated by dividing or merging OwnerZones. In the disclosed invention, however, no teaching about technology for changing the role performed by a terminal based on the terminal capability is described.

Apparatus and method for setting role based on capability of terminal


The present invention is a methodology for the delivery of freshly prepared food to a plurality of vehicle-operating consumers. Freshly prepared foods means foods that have, in some manner, recently been transformed into an edible or consumable format. Thus, when frozen ice cream is scooped into a cone, it is freshly prepared; when a frozen or cool item is microwaved to cook it or to merely heat it up, it is freshly prepared; when coffee is taken from an urn or coffeemaker and put into a cup, it is freshly prepared; when soda is dispensed from a dispenser or cooler, it is, in accordance with the present invention, freshly prepared; when frozen pizza is heated, it is freshly prepared, etc.

a. Field of Invention
The invention relates generally to present invention relates to systematic methodology for efficiently selling fast-food service products to vehicle-operating customers.
b. Description of Related Art
The following patents are representative of systems for the sale or delivery of goods to customers:
U.S. Pat. No. 7,171,377 to Nubuo Ogasawara describes a system to receive orders of merchandise such as merchandise sold in a supermarket from a large number of employees, for example, of a workplace, and to deliver the ordered merchandise in a bundle, thereby enhancing the employees' convenience and the efficiency of business. The system is provided with an order reception unit receiving an order of merchandise that can include perishable foods, a shopping list creating unit receiving one or more shopping lists corresponding to the orders from clients, a merchandise packing instruction unit receiving one or more shopping lists, and instructing picking and packing of the ordered merchandise corresponding to one or more clients to a packing worker, and a merchandise delivery unit delivering the packed merchandise to the delivery locations corresponding to one or more clients.
U.S. Pat. No. 6,598,514 B2 to Aurelio Leggi which comprises a kiosk that enables pasta portions of the type forming the classical Italian first course to be prepared, the kiosk including an automatic pasta cooking machine; a cooking hob for amalgamating within a suitable container, by heating accompanied by mixing, the required sauces or condiments with the pasta previously cooked in the pasta cooking machine; and a heating element for heating the sauces or condiments and/or for maintaining them hot.
U.S. Pat. No. 5,572,984 to Lorne B. Alden et al. shows a modular kiosk for use in the food service industry which is described. The kiosk includes one or more structural units having upstanding sides and back, and a horizontal roof with couplings on the back thereof for coupling appliances disposed in the unit to sources of energy. The unit typically would have metal, upper and lower sections, each receiving a different appliance for cooking or storing food. The unit can include a hood disposed at eye level and a griddle or deep fat fryer disposed below the hood in the middle section. When a hood is included, the hood is intended to be coupled to a flue. The device is intended to be used in malls and open areas for cooking and dispensing food.
Notwithstanding the prior art, the present invention is neither taught nor rendered obvious thereby.

Freshly prepared food delivery methodology


Systems and techniques by which a single electronic device can implement a variety of customized control interfaces. The control interfaces can be tailored to specific operations performed the device which is controlled. In one aspect, computer-implemented methods for controlling a web-based application include providing, from a server, a web page that includes a web-based application and a uniform resource identifier specifying a control interface for the web-based application and transmitting the control interface specified by the uniform resource identifier to a client for use in controlling the one or more functions of the web-based application. The control interface is configured to permit a user to control one or more functions of the web-based application from a mobile device.

Modern electronic devices provide a staggering array of functionality to users. Portable handheld electronic devices such as telephones, music players, PDA's, and game players can display information on display screens, receive instructions from a user, communicate with other devices using wired and wireless data links, take digital photographs, and process large volumes of digital data at speeds that were unthinkable even a generation ago.
Such functionality can be provided, in part, using graphical displays that act as both inputs and outputs. For example, touch screens include a display screen and detect the presence and location of manual interaction with that display screen. A user can interact with the elements shown on the display screen intuitively, in ways that resemble the ways that humans interact with the world outside of graphical displays and electronic devices.

Implementing customized control interfaces


A method implemented in a transmission apparatus used in an optical fiber communications system for a polarization switched differential quaternary phase-shift keying (DQPSK) signal is disclosed. The method comprises splitting data into two or more data streams, inputting said two or more data streams to 1-bit DQPSK precoders to perform 1-bit DQPSK precoding, and multiplexing inphase outputs of the 1-bit DQPSK precoders to generate a first output; and multiplexing quadrature outputs of the 1-bit DQPSK precoders to generate a second output. Other methods, apparatuses, and systems also are disclosed.

The present invention relates to polarization switching in the field of optical fiber communications and, more particularly, to special design of bit precoders.
Performance of optical fiber communications is limited by an optical signal-to-noise ratio and fiber nonlinearity. To enhance the fiber nonlinearity tolerance, polarization switching has been proposed to reduce the nonlinear cross-talk between adjacent symbols [1]. The advantages of polarization switching have been demonstrated in experiments. Polarization switching formats requires special design of bit precoders, such as 2-bit precoders for the differential quaternary phase-shift keying (DQPSK) format. A 2-bit DQPSK precoder may work as illustrated in FIG. 3. So far, however, no particular documents have been reported to implement the polarization switching in the field, because no such 2-bits differential precoder is available. At this moment, no product has been developed to perform 2-bit DQPSK precoding. Commercially available differential DQPSK precoders only perform the precoding scheme on a symbol-by-symbol basis. It is very costly to redesign the whole application-specific integrated circuit (ASIC) chips. A 1-bit DQPSK precoder [2] could be re-designed to perform 2-bit differential encoding, though the cost would be much higher than our proposed structure as follows:
We propose to use a combination of discrete components such as commercial 1-bit DQPSK precoders to construct a 2-bit DQPSK precoder, thus enabling the commercial deployment of polarization switched signals in the DQPSK system. It is the first time that a feasible scheme is proposed to allow polarization switching DQPSK being deployed in an actual optical transmission system.
[1] J. K. Fischer, and K. Petermann, "Performance Analysis of CSRZ-OOK With Pairwise or Pulse-to-Pulse Alternate Polarization", IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 19, NO. 24, DEC. 15, 2007
[2] Product Brief, SMI4029, http://www.semtech.com/images/datasheet/smi4029.pdf

Polarization switching for optical fiber communications