By providing a barrier layer stack including a silicon nitride layer for confining a copper-based metal region, thereby also effectively avoiding any diffusion of oxygen and moisture into the copper region, and a nitrogen-enriched silicon carbide layer, the total relative permittivity may be maintained at a low level, since the thickness of the silicon nitride layer may be moderately thin, while the relatively thick silicon carbide nitride layer provides the required high etch selectivity during a subsequent patterning process of the low-k dielectric layer.

1. Field of the Invention
Generally, the present invention relates to the formation of integrated circuits, and, more particularly, to the formation of metallization layers including highly conductive metals, such as copper, embedded into a dielectric material having low permittivity to enhance device performance.
2. Description of the Related Art
In modern integrated circuits, minimum feature sizes, such as the channel length of field effect transistors, have reached the deep sub-micron range, thereby steadily increasing performance of these circuits in terms of speed and power consumption. As the size of the individual circuit elements is significantly reduced, thereby improving, for example, the switching speed of the transistor elements, the available floor space for interconnect lines electrically connecting the individual circuit elements is also decreased. Consequently, the dimensions of these interconnect lines have to be reduced to compensate for a reduced amount of available floor space and for an increased number of circuit elements provided per chip.
In integrated circuits having minimum dimensions of approximately 0.35 μm and less, a limiting factor of device performance is the signal propagation delay caused by the switching speed of the transistor elements. As the channel length of these transistor elements has now reached 0.18 μm and less, it turns out, however, that the signal propagation delay is no longer limited by the field effect transistors, but is limited, owing to the increased circuit density, by the close proximity of the interconnect lines, since the line-to-line capacitance is increased, in combination with a reduced conductivity of the lines due to their reduced cross-sectional area. The parasitic RC time constants, therefore, require the introduction of a new type of material for forming the metallization layer.
Traditionally, metallization layers are formed by a dielectric layer stack including, for example, silicon dioxide and/or silicon nitride with aluminum as the typical metal. Since aluminum exhibits significant electromigration at higher current densities than may be necessary in integrated circuits having extremely scaled feature sizes, aluminum is being replaced by copper, which has a significantly lower electrical resistance and a higher resistivity against electromigration. For devices having feature sizes of 0.13 μm and less, it turns out that simply replacing aluminum with copper does not provide the required decrease of the parasitic RC time constants, and therefore the well-established and well-known dielectric materials silicon dioxide (k≈4.2) and silicon nitride (k≈7) are increasingly replaced by so-called low-k dielectric materials. However, the transition from the well-known and well-established aluminum/silicon dioxide metallization layer to a low-k dielectric/copper metallization layer is associated with a plurality of issues to be dealt with.
For example, copper may not be deposited in higher amounts in an efficient manner by well-established deposition methods, such as chemical and physical vapor deposition. Moreover, copper may not be efficiently patterned by well-established anisotropic etch processes and therefore the so-called damascene technique is employed in forming metallization layers including copper lines. Typically, in the damascene technique, the dielectric layer is deposited and then patterned with trenches and vias that are subsequently filled with copper by plating methods, such as electroplating or electroless plating. Also, the damascene technique is presently a well established technique for forming copper metallization layers in standard dielectric materials, such as silicon dioxide. The employment of low-k dielectrics requires the development of new dielectric diffusion barrier layers to avoid copper contamination of adjacent material layers, as copper readily diffuses in a plurality of dielectrics. Although silicon nitride is known as an effective copper diffusion barrier, which may also efficiently avoid the diffusion of, for instance, oxygen into the copper-based metal, silicon nitride may not be acceptable in certain applications using low-k dielectric layer stacks owing to its high permittivity and also reduced etch selectivity in sophisticated via etch processes. Therefore, presently, silicon carbide is considered as a viable candidate for a copper diffusion barrier. It turns out, however, that copper's resistance against electromigration strongly depends on the interface between the copper and the adjacent diffusion barrier layer, and, therefore, in sophisticated integrated circuits featuring high current densities, it is generally preferable to use up to 20% nitrogen in the silicon carbide layer, thereby remarkably improving the electromigration behavior of copper compared to pure silicon carbide.
With reference to FIGS. 1a-1e, a typical conventional process flow will now be described to explain the problems involved in forming a metallization layer including copper and a low-k dielectric in more detail.
FIG. 1a schematically shows a cross-sectional view of a semiconductor structure 100, in which a low-k dielectric material is to be patterned in accordance with a so-called via first/trench last process sequence, which is presently considered as a very promising process scheme in patterning low-k dielectrics. The semiconductor structure 100 comprises a substrate 101 that may include circuit elements, such as transistors, resistors, capacitors and the like, and which may include a lower metallization layer 102 including a metal region 103 embedded in a dielectric material 104. Depending on the level of the lower metallization layer 102, the metal region 103 may comprise copper and the dielectric material 104 may be a low-k dielectric, such as hydrogen-containing silicon oxycarbide (SiCOH). A barrier layer 105 formed of nitrogen-containing silicon carbide (SiCN), which also serves as an etch stop layer in the following etch procedure for patterning an overlying low-k dielectric layer 106, is formed on the metallization layer 102, thereby confining the metal region 103. The low-k dielectric layer 106 may comprise, depending on the process sequence used, an intermediate etch stop layer (not shown), which in many applications may be omitted for the benefit of a reduced total permittivity. The low-k dielectric material in the layer 106 may be comprised of any appropriate low-k dielectric material, such as SiCOH and the like. A cap layer 108, for example comprised of silicon dioxide or provided as an anti-reflective coating (ARC), may be optionally located on the low-k dielectric layer 106 and may then serve as a stop layer in removing excess copper in a subsequent chemical mechanical polishing (CMP) process. A resist mask 109 including an opening 110 is formed above the optional cap layer 108.
A typical process flow for forming the semiconductor structure 100 as shown in FIG. 1a may comprise the following steps. After planarizing the lower metallization layer 102, the barrier/etch stop layer 105 is deposited, for example by plasma enhanced chemical vapor deposition (PECVD), from trimethyl silane (3MS) and ammonia (NH3) as precursor gases. Then, the hydrogen-containing silicon oxycarbide is deposited, wherein, if required, the optional etch stop layer may be formed when a first thickness corresponding to a trench depth is obtained during the deposition of the dielectric layer 106. In this case, the deposition of the layer 106 may be resumed to achieve the required final thickness of the layer 106. Next, the cap layer 108, if required, is deposited with a specified thickness. The cap layer 108 may help to substantially reduce an interaction of the low-k dielectric of the layer 106 with the overlying resist mask 109 and may serve as a CMP stop layer. Then, the resist mask 109 is patterned in accordance with well-established deep UV lithography techniques to form the opening 110 determining the dimensions of the vias to be formed within the dielectric layer 106.
FIG. 1b schematically shows the semiconductor structure 100 after an anisotropic etch process for forming a via 111 in the cap layer 108 and the dielectric layer 106. During the anisotropic etch procedure, the barrier/etch stop layer 105 exhibits a significantly lower etch rate than the surrounding dielectric layer 106, so that the etch process may be stopped in or on the layer 105, wherein the layer 105 comprised of SiCN may exhibit an enhanced etch selectivity compared to an SiN layer, as may frequently be used for an etch stop layer. Thereafter, the remaining photoresist not consumed during the anisotropic etch process is removed by an etch step in an oxygen-containing plasma ambient. It should be noted that the etch stop layer 105 may not suppress oxygen diffusion into the metal region 103 during resist ashing and any other subsequent manufacturing processes as efficiently as an SiN layer and hence the copper integrity may be reduced.
FIG. 1c schematically shows the semiconductor structure 100 in an advanced manufacturing stage. The via 111 is filled with an organic anti-reflective coating material to form a via plug 114, while the organic material is also provided at the remaining surface of the structure 100 to form an anti-reflective coating layer 112 for the subsequent photolithography. Thus, the plug 114 and the anti-reflective coating 112 serve to planarize the topography of the semiconductor structure 100 prior to the formation of a further photoresist mask 113 including a trench opening 115. The via plug 114 and the anti-reflective coating 112 may be formed by spin-on techniques and the like, and the photoresist mask 113 may be formed by sophisticated lithography methods, as are well known in the art.
FIG. 1d schematically shows the semiconductor structure 100 after completion of the trench-forming step and removal of the layer 112 and the plug 1 14. That is, a trench 117 is formed in the underlying cap layer 108 and the upper portion of the dielectric layer 106. The trench 117 may be formed on the basis of well-established etch techniques. Subsequently, the etch stop layer 105 may be completely opened. During this etch process, the degree of "over-etching" of the copper region 103 may depend on the uniformity of the previous etch process for forming the via opening 111 and thus on the selectivity of the etch stop layer 105, since a reduced etch selectivity may result in reduced thickness uniformity of the etch stop layer 105 within the via opening 111 after the via etch process. After etching through the etch stop layer 105 within the opening 111, a barrier metal and a copper-based metal may be filled in the trench 117 and the via opening 111.
FIG. 1e schematically shows the semiconductor structure 100 after completion of the above-described process sequence, thereby forming a metallization layer 130. The metallization layer 130 comprises the trench 117 and the via 111 filed with a copper-based metal 119, wherein a barrier metal layer 118 is formed on inner sidewalls of the trench 117 and via 111 and on the bottom surfaces thereof. A surface 120 of the metallization layer 130 is planarized to allow the formation of a further metallization layer.
Typically, the barrier metal layer 118 may be deposited by physical vapor deposition, such as sputter deposition, with a thickness that insures sufficient protection against copper out-diffusion and at the same time provides required adhesion to the surrounding low-k dielectric material. Typically, tantalum or tantalum nitride may be used as material for the barrier metal layer 118. Subsequently, a copper seed layer is deposited to promote the subsequent deposition of the bulk copper by electroplating. Then, the excess copper is removed by chemical mechanical polishing, wherein the cap layer 108 may also be removed, at least partially, and may act as a stop layer to reliably control the CMP process. Thereafter, a further etch stop layer, such as the layer 105, may be deposited to confine the copper and provide a reliable etch stop during the formation of a subsequent metallization layer.
The electromigration of copper strongly depends on the characteristics of the interface to the surrounding material. It is, therefore, important to maintain the integrity of the copper-based metal at regions 121, in which the copper of the metal region 103 is in contact with the barrier/etch stop layer 105 or with an etch stop layer still to be formed on the metal 119. As previously explained, the SiNC material of the layer 105 may have, despite its superior behavior in view of etch selectivity and permittivity, a reduced diffusion blocking effect with respect to, for instance, moisture and oxygen, compared to SiN. Hence, reduced performance of the metal region 103 or 119 may result, thereby compromising the overall performance of the device 100.
In view of the above problems, a need exists for a technique that maintains superior barrier characteristics while avoiding, or reducing the effects of, one or more of the problems identified above.

Etch stop layer for a metallization layer with enhanced etch selectivity and hermeticity


A Bluetooth master device is capable of performing search and connection method for Bluetooth devices. The Bluetooth master device receives device information from at least one Bluetooth device in response to a Bluetooth device search request made by a user. A responding Bluetooth device that is capable of providing a Bluetooth service in a preset service list is selected. The Bluetooth master device sends a name request signal to the selected Bluetooth device and displays a device name received from the selected Bluetooth device.

Advances in wireless communication technology have enabled development of low-cost and low-power wireless devices and links. Bluetooth® is a representative short-range communication scheme that enables low-cost and low-power voice and data communication between devices.
In typical Bluetooth® communication, a master device and multiple slave devices are interconnected to form a piconet. The master device initiates Bluetooth® communication by sending a Bluetooth® signal, and a slave device receives the Bluetooth® signal from the master device and communicates with the master device.
A Bluetooth® device desiring to be a master may set a frequency hopping sequence and broadcast an inquiry signal carrying the frequency hopping sequence to search for another Bluetooth® device in the vicinity. A Bluetooth® device conducting an inquiry scan may respond to the inquiry signal by sending an inquiry response signal carrying Bluetooth® Device Address (BD_ADDR) and clock information to the inquiring Bluetooth® device.
In the case where a few Bluetooth® devices are present in the vicinity, the number of responding Bluetooth® devices is small, and the inquiring Bluetooth® device may list most of the responding Bluetooth® devices on the display screen. The user of the inquiring Bluetooth® device may readily select a desired one of the listed Bluetooth® devices for communication. However, in the case where many Bluetooth® devices are present in the vicinity, the number of responding Bluetooth® devices may be not small and the inquiring Bluetooth® device may have to spend a long time to finish the inquiry procedure. In particular, when the inquiry list presented by the inquiring Bluetooth® device is limited in number of Bluetooth® devices, a Bluetooth® device desired by the user may be not present in the inquiry list. Hence, it is necessary to develop a method that enables efficient discovery of a desired Bluetooth device when many Bluetooth® devices are present in the vicinity.
Additionally, in the case when a first Bluetooth® device had communicated with a second Bluetooth® device in the past or the second Bluetooth® device is aware of the first Bluetooth® device, the second Bluetooth® device may repeatedly try to connect to the first Bluetooth® device even when the user of the first Bluetooth® device desires not to connect to the second Bluetooth® device. That is, the second Bluetooth® device may interfere with the first Bluetooth® device, preventing efficient Bluetooth® communication. Hence, it is necessary to develop a method that may effectively block connection with an undesired Bluetooth® device.

Method for searching and connecting Bluetooth devices and apparatus using the same


A differential input circuit has two halves, each half includes a differential input voltage terminal with a first emitter follower having its base terminal connected to the input terminal, having a collector terminal connected to a first voltage terminal, an emitter terminal connected to a first terminal of an emitter resistor. A second emitter follower is provided having has its base terminal connected to the first differential input terminal, having a collector terminal connected to the first voltage terminal, and having an emitter terminal. A diode-connected transistor is provided having an emitter terminal connected to the emitter terminal of the second emitter follower, having its base and collector terminals connected together. A current source is provided having an output terminal connected to the base and collector terminals of the first diode-connected transistor, and having an input terminal connected to a second voltage terminal. An output drive transistor is provided having its base terminal connected to the base and collector terminals of the first diode-connected transistor, having its emitter terminal connected to the first terminal of the emitter resistor, and having a collector terminal for providing a differential output current.

1. Field of the Invention
This invention relates to operational amplifier circuits and, more particularly, to improvements in the speed of the differential input stage for an operational amplifier.
2. Prior Art
To increase the slew rate of an operational amplifier while maintaining a fixed unity gain-bandwidth product, g.sub.m can be reduced by using emitter resistors in the input stage to provide emitter degeneration. The emitter resistors reduce the g.sub.m of the amplifier and provide better slew-rate and pulse response. A disadvantage of using emitter degeneration in the input stage is the degradation of the DC performance of the amplifier resulting in lower gain, lower common mode rejection ratio (CMRR), lower power supply rejection ratio (PSRR), and high offset voltage (Vos).
Emitter degeneration can be used along with matched DC current sources so that no DC current flows through the emitter resistor. This provides reduced g.sub.m and improved DC performance, but two matched DC current sources are required, and increased tub capacitance becomes a problem.
FIG. 1 shows a circuit diagram of a basic, prior-art operational amplifier circuit 100. The operational amplifier is a differential amplifier which has two input signal voltages and which provides an output voltage which is proportional to the difference between the two input signal voltages. A differential input stage 102 for this amplifier circuit includes a pair of PNP transistors. The first PNP transistor 104 has a base terminal 105, and emitter terminal 106, and a collector terminal 107. The second PNP transistor 108 has a base terminal 109, and emitter terminal 110, and a collector terminal 111. A differential input voltage V.sub.in is applied between the base terminals 105, 109. The emitter terminal 106 has one end of an emitter resistor 112 connected thereto. The other end of the emitter resistor 112 is connected to the output terminal 114 of a constant current source 116. The input terminal 118 of the constant current source 116 is connected to a +Vcc supply voltage. The value of the current from the constant current source 116 is represented as I.sub.t. The emitter terminal 110 has one end of another emitter resistor 120 connected thereto. The other end of the emitter resistor 120 is connected to the output terminal 114 of the constant current source 116.
The collector loads for the PNP transistors of the differential input stage 102 are respective transistors of a diode-transistor current mirror circuit 122 formed with a first diode-connected NPN transistor 124 and a second NPN transistor 126. The collector terminal 107 of the first PNP transistor 104 is connected to the collector terminal 128 and the base terminal of the diode-connected NPN transistor 124, which are tied together. The emitter terminal 132 of the diode-connected NPN transistor 124 is connected to a ground voltage terminal 134. The collector terminal 111 of the second PNP transistor 108 is connected to the collector terminal 138 of the NPN transistor 126. The base terminal 138 of the NPN transistor 126 is connected to the base terminal 130 of the NPN transistor 104. The emitter terminal 140 of the NPN transistor 126 is connected to the ground voltage terminal 134.
An output amplifier stage 142 has its input terminal 144 connected to the collector terminal 136 of the NPN transistor 126. An output voltage signal V.sub.out is provided at the output terminal 146 of the output amplifier 142. A compensation capacitor C.sub.c represents the capacitance between the input terminal 144 and the output terminal 146 of the amplifier 142.
The slew rate of the operational amplifier circuit 100 is the internally-limited rate of change in output voltage when a large-amplitude step function is applied to the input terminal of an operational amplifier. Slew rate is equal to I.sub.t /C.sub.c.
The unity gain-bandwidth product is the frequency range from DC to the frequency where the open-loop gain of an operational amplifier rolls off to a value of one. Unity gain-bandwidth product is approximately g.sub.m /C.sub.c.
To increase the slew rate for a fixed unity gain-bandwidth product, g.sub.m is reduced by the using the emitter resistors 112, 120. The emitter resistors 112, 120 provide emitter degeneration which reduces g.sub.m and provides better slew-rate and pulse response. The disadvantage of using emitter degeneration as shown in FIG. 1 is the reduction in DC performance by providing lower gain, lower common mode rejection ratio (CMRR), lower power supply rejection ratio (PSRR), and higher DC offset voltage (Vos).
FIG. 2 illustrates a typical prior-art operational amplifier circuit 200 which provides reduced g.sub.m but with better DC performance than the circuit of FIG. 1. A differential input stage 202 for this amplifier includes a pair of NPN transistors. The first NPN transistor 204 has a base terminal 205, and emitter terminal 206, and a collector terminal 207. The second NPN transistor 208 has a base terminal 209, an emitter terminal 210, and a collector terminal 211. A differential input voltage V.sub.in is applied between the base terminals 205, 209. An emitter resistor 212 is connected between the emitter terminal 206 and the emitter terminal 210. A first constant current source 214 has its input terminal 216 connected to the emitter terminal 206 and its output terminal 218 connected to a ground voltage terminal 220. A second constant current source 222 has its input terminal 224 connected to the emitter terminal 210 and its output terminal 226 connected to the ground voltage terminal 220. The collector terminals 207, 211 are connected to the input terminals of a current mirror circuit 228.
This circuit has reduced g.sub.m with improved DC performance. No DC current flows through the emitter resistor 212, but two matched DC current sources 214, 222 are required, and the differential pair needs to drive the two tub capacitances of the current sources 214 and 222.
FIG. 3 shows a circuit diagram of another prior-art operational amplifier 300 having improved slew rate. A differential input stage 302 includes a pair of PNP transistors and a pair of NPN transistors. The first PNP transistor 306 has a base terminal 307, an emitter terminal 308, and a collector terminal 309. The second PNP transistor 310 has a base terminal 311, an emitter terminal 312, and a collector terminal 313. A differential input voltage V.sub.in is applied between input terminals 305, 314, which are connected to respective base terminals 307, 311. The emitter terminal 306 has one end of an emitter resistor 316 connected thereto. The other end of the emitter resistor 316 is connected to the output terminal 318 of a constant current source 320. The input terminal 322 of the constant current source 320 is connected to a +Vcc supply voltage. The value of the current from the constant current source 320 is represented as I.sub.t. The emitter terminal 312 has one end of another emitter resistor 324 connected thereto. The other end of the emitter resistor 324 is connected to the output terminal 318 of the constant current source 320. The collector terminal 309 of the PNP transistor 306 is connected to a -Vcc supply voltage.
The first NPN transistor 336 has a base terminal 337, an emitter terminal 338, and a collector terminal 339. The second NPN transistor 340 has a base terminal 341, an emitter terminal 342, and a collector terminal 343. The input terminals 305, 314, to which the differential input voltage V.sub.in is applied, are also connected to respective base terminals 337, 341. The emitter terminal 338 has one end of an emitter resistor 344 connected thereto. The other end of the emitter resistor 344 is connected to the input terminal 346 of a constant current source 348. The output terminal 350 of the constant current source 348 is connected to a -Vcc supply voltage. The value of the current from the constant current source 348 is represented as I.sub.t. The emitter terminal 342 has one end of another emitter resistor 354 connected thereto. The other end of the emitter resistor 354 is connected to the input terminal 346 of the constant current source 348. The collector terminal 339 of the NPN transistor 336 is connected to a +Vcc supply voltage.
The collector terminal 313 of the PNP transistor 310 is connected to the current input terminal 360 of a bottom current mirror circuit 362. The bottom current mirror circuit 362 has a voltage supply terminal 364 which is connected to the -Vcc supply voltage. The collector terminal 343 of the NPN transistor 340 is connected to the current input terminal 366 of a top current mirror circuit 368. The top current mirror circuit 368 has a voltage supply terminal 370 which is connected to the +Vcc supply voltage.
The current output terminal 372 of the top current mirror circuit 368 and the current output terminal 374 of the bottom current mirror circuit 362 are both connected to the input terminal of the output buffer amplifier 378, which has an output terminal 380.
In contrast to the performance of the circuit of FIG. 1, the slew rate for the circuit of FIG. 3 is twice that of FIG. 1, or 2. The two current sources 320, 348 limit the slew rate.
FIG. 4 shows a circuit diagram of a prior-art operational amplifier 400. A differential emitter-follower input stage includes a pair 402 of PNP-NPN emitter-follower transistors and a pair 404 of NPN-PNP emitter follower transistors.
The pair 402 of PNP-NPN transistors includes a first PNP transistor 406 which has its collector terminal 407 connected to a negative voltage supply. Its base terminal 408 is connected to one differential input terminal 409 of the amplifier 400. Its emitter terminal 410 connected to the output terminal 411 of a constant current source 412. The input terminal 413 of the constant current source 412 is connected to a positive voltage supply. The emitter terminal 411 is also connected to the base terminal 414 of an NPN transistor 415. The collector terminal 416 is also connected to the positive voltage supply. The emitter terminal 417 is connected to one terminal 418 of an emitter resister 419.
The pair 402 of PNP-NPN transistors includes a second PNP transistor 420 which has its collector terminal 421 connected to the negative voltage supply. Its base terminal 422 is connected to the other differential input terminal 423 of the amplifier 400. Its emitter terminal 424 is connected to the output terminal of a constant current source 425. The input terminal 426 of the constant current source 425 is connected to the positive voltage supply. The emitter terminal 424 is also connected to the base terminal 427 of an NPN transistor 428. The emitter terminal 429 is connected to the other terminal 430 of the emitter resistor 419.
The collector terminal 431 is connected to an input current terminal 432 of a top current mirror circuit 433. The top current mirror circuit 433 has an output current terminal 434 which is connected to the input terminal 435 of an output buffer amplifier 436 having an output terminal 437.
In a similar manner, the pair 404 of NPN-PNP transistors includes a first NPN transistor 456 which has its collector terminal 457 connected to a positive voltage supply. Its base terminal 458 is connected to the one differential input terminal 409 of the amplifier 400. Its emitter terminal 460 is connected to the input terminal 461 of a constant current source 462. The output terminal 463 of the constant current source 462 is connected to a negative voltage supply. The emitter terminal 461 is also connected to the base terminal 464 of an PNP transistor 465. The collector terminal 466 is also connected to the negative voltage supply. The emitter terminal 467 is connected to the one terminal 418 of an emitter resister 419.
The pair 404 of NPN-PNP transistors includes a second NPN transistor 470 which has its collector terminal 471 connected to the positive voltage supply. Its base terminal 472 is connected to the other differential input terminal 423 of the amplifier 400. Its emitter terminal 474 is connected to the input terminal of a constant current source 475. The output terminal 476 of the constant current source 475 is connected to the negative voltage supply. The emitter terminal 474 is also connected to the gate terminal 477 of an PNP transistor 478. The emitter terminal 479 is connected to the other terminal 430 of the emitter resistor 419.
The collector terminal 481 is connected to an input current terminal 482 of a bottom current mirror circuit 483. The bottom current mirror circuit 483 has an output current terminal 484 which is connected to the input terminal 435 of the output buffer amplifier 436.
One problem with this type of amplifier is that it requires DC-balancing by adjustment of the four constant current sources 412, 425, 462, 475. The V.sub.BE voltage drops across the PNP and the NPN transistors are also slightly different and need to be matched to get a low Vos.

Balanced, high-speed differential input stage for Op-amps


A connector includes a base, at least one first terminal, an upper cover, and a sliding structure. The base includes two opposite sides for defining the receiving space. The first terminal includes a contact end and a fixed end, wherein the contact end is disposed in the receiving space and the fixed end extends outside the receiving space. The upper cover includes two opposite edges. The sliding structure is disposed on the two opposite sides of the base that correspond to the two opposite edges of the upper cover. In this sliding structure, the two opposite edges are able to slide along the two opposite sides.

1. Field of the Invention
The present invention relates to a connector, and more specifically, to a connector with a sliding upper cover.
2. Descriptions of the Related Art
Many signal cables are used in electrical appliances to connect the printed circuit boards (PCBs) for signal transmission. One of the more popular signal cables is a soft and flat pipeline with a plurality of pins at both ends. Correspondingly, one or more connectors can be configured onto the PCB for connecting to the signal cables. A plurality of pins is also arranged at the end of each connector and corresponds to the pins at the terminal of each signal cable. After the signal cable is plugged into the connector, the signals can be transmitted therebetween.
FIGS. 1A and 1B schematically illustrate a conventional connector 100, comprising a cover 110 which can be opened pivotally as a piano lid. The cover 110 of the connector 100 is normally closed. When the signal cable 120 needs to be electrically connected to the inner terminal hidden under the cover 110, the cover can be pivotally turned to reveal the inner terminal. After the signal cable 120 is connected to the connector 100, the cover 110 is returned to the closed position so as to protect the connector and the signal cable underneath. A disadvantage of this conventional connector is that it requires a multitude of steps to establish a connection with the signal cable. Moreover, opening the cover requires more space and is unfavorable in today's technological trend of decreasing sizes. Furthermore, with either frequent closing and opening or improper usage, the cover 110 or the pivoting mechanism 130 can be easily damaged. When the cover of the connector is damaged, it is difficult to repair or replace the cover only because the entire connector needs to be replaced, thereby increasing the cost of the product.
Thus, it is advantageous to redesign the structure of the connector not only to increase the connection stability to the signal cables, but also to plug in the signal cables more conveniently. In addition, an option to repair or replace only the cover without having to replace the entire connector is desired. Lastly, the steps in establishing a connection with the signal cable should be simplified.

Electrical connector with a sliding upper cover


A charge storage memory is configured in a NAND array, and includes NAND strings coupled to bit lines via string select switches and includes word lines. A controller is configured to produce a program bias pulse by biasing the bit lines and string select lines in a first condition; setting a word line coupled to a target cell to a first voltage level while the bit lines and string select lines are in the first condition; thereafter, biasing the bit lines and string select lines in a second condition; and setting the word line coupled to the target cell to a second voltage level higher than the first voltage level while the bit lines and string select lines are in the second condition. Program bias pulses produced in this manner can be used in a modulated incremental stepped pulse programming sequence.

1. Field of the Invention
The present invention relates to flash memory technology, and more particularly to flash memory suitable for high density implementations.
2. Description of Related Art
Flash memory is a class of non-volatile integrated circuit memory technology. Traditional flash memory employs floating gate memory cells. Another type of memory cell used for flash memory can be referred to as a charge trapping memory cell, which uses a dielectric charge trapping layer in place of the floating gate.
The typical flash memory cell consists of a field effect transistor FET structure having a source and drain separated by a channel, and a gate separated from the channel by a charge storage structure including a tunnel dielectric layer, the charge storage layer (floating gate or dielectric), and a blocking dielectric layer. According to the early conventional charge trapping memory designs referred to as SONOS devices, the source, drain and channel are formed in a silicon substrate (S), the tunnel dielectric layer is formed of silicon oxide (O), the charge storage layer is formed of silicon nitride (N), the blocking dielectric layer is formed of silicon oxide (O), and the gate comprises polysilicon (S).
Data is stored in a flash memory device by controlling the amount of charge trapped in the charge storage structure. The amount of charge stored sets a threshold voltage for the memory cell in flash memory devices, which allows the data to be read.
As specifications for the values of target threshold voltages tighten for low voltage applications, and for applications that store multiple bits per cell, problems are arising with precise control over the amount of charge stored in a target cell during a program operation, and with prevention of disturbance of the charge stored in the memory cells by program and erase operations directed at other cells.
It is desirable to provide a new memory technology that provides for finer control over the charge storage in flash memory.

Flash programming technology for improved margin and inhibiting disturbance


The housing of a transducer supports both dynamic and static pressure sensors to obtain depth information as well as pressure wave signals. A semiconductive diaphragm with diffused resistances connected in a bridge is used as the static sensor which is centrally located on an end face of the housing. Several parallel-connected dynamic sensor elements are arrayed around the static sensor. Each dynamic sensor element is an edge supported brass disk with a thin piezoelectric ceramic disk soldered to it such that the disks flex in response to low frequency pressure waves to generate corresponding electrical signals. A low noise amplifier and filter is capacitively coupled to the dynamic sensor array to process hydrophone signals at a frequency below 1 Hz.

Hydrophones have been used for many years for detection and location of ships and submarines and other underwater targets. Hydrophones are also used for sensing sonic waves in underwater geophysical exploration. A hydrophone receives sonic waves from underwater sources such as noise generated by a submarine or sonic waves reflected from an object. A single hydrophone may be used for "listening" for the presence of a surface object or an underwater object or for sensing small pressure waves.
The hydrophone is a dynamic sensor or transducer which converts the pressure waves in the water to electrical signals. An associated circuit with filtering and amplification functions conditions the signal for transmission via a cable to an electronics unit where the information is evaluated for data collection or for tactical purposes. Low frequency dynamic sensors are needed for high resolution pressure change measurement at frequencies much less than 1 Hz.
A useful bit of information for the evaluation of hydrophone signals is the depth of the hydrophone. A variable reluctance type dynamic transducer and the associated circuit has been proposed to provide a measure of static pressure which correlates to depth as well as dynamic pressure changes, but this requires a compromise in design so that neither the static pressure or dynamic pressure measuring functions are optimized.
It is already known to incorporate more than one sensor element and specifically more than one type of sensor in an underwater instrument. The Seaver U.S. Pat. No. 4,749,254 discloses an oceanographic instrument having an optical sensor system for measuring temperature, pressure and the index of refraction. The Savit U.S. Pat. No. 4,648,082 discloses an optical pressure gradient sensor for sensing the direction and magnitude of an acoustic wave propagating through a fluid. The Junod et al U.S. Pat. No. 4,315,324 discloses a hydrophone having two independent oscillators for a pressure sensor. However, the prior art does not appear to disclose separate sensors for measuring pressure wave events and depth. Generally the prior art transducers are operative at acoustic frequencies above 1 Hz and do not provide a means for measuring pressure waves which have a frequency below 1 Hz.

Low frequency hydrophone and depth sensor assembly


The invention relates to activities and characteristics of tumor-associated macrophages (TAMs). In particular, immunoglobulin single variable domains are provided against markers of TAMs, and methods using the same for in vivo imaging of tumor cells, as well as cancer diagnostics and therapeutics.

Tumors harbor dynamic microenvironments in which cancer cells are intimately associated with non-transformed host cells. The tumor-associated stroma is considered to play an important role during tumor growth, influencing phenomena such as angiogenesis, metastasis and immune suppression.(36) As such, the stroma forms an attractive target for diagnostic and therapeutic applications.(37)
Different myeloid cells are important components of the tumor stroma. Myeloid cells are frequently found to infiltrate tumors and have been linked to diverse tumor-promoting activities.(1) In particular, tumor-associated macrophages (TAMs) are an important component of the tumor stroma, both in murine models and human patients.(2) TAMs can promote tumor-growth by affecting angiogenesis, immune suppression and invasion and metastasis.(2,3)
Tissue-resident macrophages can be maintained through local proliferation or differentiation in situ from circulating monocytic precursors.(5) Importantly, discrete subsets of blood monocytes have been described. Mouse monocytes can be classified as Ly6ClowCX3CR1hi(CCR2−CD62L−) or Ly6ChiCX3CR1low (CCR2+CD62L+) and are shown to have distinct functions and migration patterns. (6)
Macrophages are plastic cells that can adopt different phenotypes depending on the immune context. Microenvironmental stimuli can drive a macrophage either towards a "classical" (M1) or an "alternative" (M2) activation state, two extremes in a spectrum.(7) M1 macrophages are typically characterized by the expression of pro-inflammatory cytokines, inducible nitric oxide synthase 2 (Nos2) and MHC Class II molecules. M2 macrophages, have a decreased level of the aforementioned molecules and are identified by their signature-expression of a variety of markers, including arginase-1 and mannose and scavenger receptors. It has been suggested that TAMs display a M2-like phenotype.(8)
Despite the presence of TAM in tumor infiltrate and their potential to produce angiogenic factors, their role in tumor growth and development remains unclear. There remains a need to discover and understand the complexities of the tumor-infiltrating myeloid cell compartment in view of the selective treatment of tumor growth.

Targeting and in vivo imaging of tumor-associated macrophages


A method of varying focus in a scene. Specifically, one embodiment of the present invention discloses a method for modeling a scene using a parametric texture map (PTM) under varying focus conditions of one or more dimensions: e.g., focus depth and depth of field. A dataset of photographs is obtained under separate focus conditions. Approximation of the dataset creates an associated PTM representation that is capable of generating scenes of the photographic scene under varying focus conditions anywhere within the range of focus conditions specified by the initial data set. In addition, extrapolation yields results outside the range of focus conditions.

1. Field of the Invention
The present invention relates to the field of computer graphics systems. More specifically, the present invention relates to the use of parametric texture maps to model a scene under varying focus conditions
2. Related Art
Photographs provide a two-dimensional representation of a three dimensional scene as captured by an imaging device, such as a camera. A skilled photographer can manipulate the imaging device by varying focus parameters to produce different photographs of the same scene. Since there is no single representation of a scene, the art of photography involves knowing how to manipulate an imaging device to create the desired photographic representation.
Although the term xe2x80x9cphotographxe2x80x9d is used throughout this disclosure, the term, photograph, is not limited to conventional film based or digital means, but is directed towards all means of capturing images.
Heretofore, once a photograph was created, pre-production parameters used to create the photograph could not be changed. For example, focus conditions in one or more dimensions were pre-designated in the imaging device at the time of exposure in order to create the photograph. These various dimensions include focus conditions that vary in focus depth, depth of field, etc.
Unfortunately, the photograph in the prior art was dictated by the focus conditions set by the imaging device. Thus, the focus condition of the photograph was fixed and determined at the time of exposure. Once fixed, after the exposure, the photographer had no control over the focus conditions in the post production process.
For example, in an advertising campaign, a photoshoot of a static three-dimensional scene having distinct foreground and background areas is conducted. The photographer may take numerous photos at varying focus conditions in two dimensions: focal depth and depth of field. Thereafter, the photographer produces a photo-layout of the scene with photographs of varying focus conditions. Depending on the skill of the photographer, it is hoped that at least one of the photographs in the photo-layout can be used in the advertising campaign.
During the photoshoot, the photographer is limited by time, expense, and practicality. In other words, the photographer cannot take photographs over the full range of focus conditions. This is where the photographer""s skill and knowledge in the art of photography are utilized. Through experience, the photographer selects the focus conditions necessary to produce a particular photograph for the photo-layout and ultimately for the advertising campaign.
However, for each of the photographs created, the focus conditions are unchangeable. Should the photographer discover that a desired photograph, not in the photo-layout, would best represent the advertising campaign, then the photographer could not create that desired photograph in the post-production process. Instead, the photographer would have to recreate the conditions in the original photo-shoot and retake the photograph using the specific focal depth and depth of field that is associated with the desired focus condition needed.
Depending on the set-up, the particular realistic scene may or may not be able to be practically recreated. In a landscape scene, the particular condition at the original photoshoot, such as a lightning storm at sunset, may not exist. At other times, a manufactured set-up may be overly expensive and difficult to recreate. In either case, the desired photograph cannot be created without additional expense, time, and energy.
A photoshoot is conducted by a photographer skilled in the art of photography: normally a professional photographer. The professional, through years of experience and learning, can manipulate the imaging device to produce the desired focus effects (e.g., focus depth and depth of field). An amateur photographer, on the other hand, may not be skilled enough in photography to understand how focus conditions will affect the created photograph. Usually, the amateur photographer relies on the imaging device to automatically determine the exposure and select the focus parameters to effect the exposure. The imaging device may or may not produce a photograph having a desired focus condition.
For example, in a landscape photograph, the photographer may desire to have the foreground and the background in sharp focus. This would require an exposure having, among other parameters, an aperture on the lens of the imaging device giving a wider depth of field. However, the imaging device may have automatically set up the exposure with an aperture giving a shallow depth of field. As a result, the produced photograph will not give the desired wider depth of field.
Thus, a need exists for a process where pre-production decisions in creating photographs do not necessarily control and limit post-production photographs. Another need exists for a photographic process that compensates for the lack of knowledge in the area of focus effects exhibited by an amateur photographer.
The present invention provides a method for varying focus in photographs of a scene. One embodiment of the present invention provides a method that achieves the above accomplishment and which also provides for control over focus parameters at any point in the production process. Additionally, one embodiment of the present invention provides a method that achieves the above accomplishments and which also provides for a photographic process that compensates for the lack of skill by an amateur photographer in selecting focus parameters.
Specifically, one embodiment of the present invention discloses a method for modeling a scene using a parametric texture map (PTM) under varying focus conditions of one or more dimensions: e.g., focus depth and depth of field. A dataset of photographs is obtained under separate focus conditions. Performing an approximation of the dataset allows for the capability to generate a spectrum of photographs of the scene. The spectrum of photographs represent varying focus conditions anywhere within a range of focus conditions specified by the initial dataset of photographs. In addition, extrapolation yields results outside the range of focus conditions.
These and other benefits of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiments which are illustrated in the various drawing figures.

Method and apparatus for varying focus in a scene

Hewlett-Packard Development Company, L.P.


An optical recording medium includes a support substrate, and a light transmission layer 12 that is disposed so as to come in contact with the support substrate. At least one of a refractive index of the support substrate and a refractive index of the light transmission layer, and an extinction coefficient of the support substrate and an extinction coefficient of the light transmission layer is different. As such, according to the invention, a reflective layer is not formed between the support substrate and the light transmission layer, such that the support substrate and the light transmission layer directly come in contact with each other. Accordingly, since at least one of the refractive index and the extinction coefficient is different, reflection occurs at the interface between the support substrate and the light transmission layer. Therefore, data held by a plurality of pits, that are arranged on the support substrate in a spiral shape or a concentric shape, can be correctly read out.

The present invention relates to an optical recording medium and a method of manufacturing the same. More particularly, the invention relates to a read only optical recording medium and a method of manufacturing the same.
Conventionally, optical recording mediums, such as the CD or DVD, have been widely used as recording mediums for recording digital data. The optical recording mediums can be broadly divided into ROM type optical recording mediums, such as the CD-ROM and DVD-ROM, that do not enable writing and rewriting of data, write-once type optical recording mediums, such as the CD-R and DVD-R, that enable writing but not rewriting of data, and data rewritable type optical recording mediums, such as the CD-RW and DVD-RW, that enable rewriting of data.
Among these, the ROM type optical recording medium includes a support substrate that has a pit column formed during a manufacturing process, and a reflective layer that covers the pit column. In the ROM type optical recording medium, information held by the pit column can be reproduced by irradiating a laser beam onto the reflective layer from the support substrate or an opposite side to the support substrate. An optical recording medium of this type, in which the laser beam is irradiated from the support substrate, can include a so-called CD type optical recording medium or a DVD type optical recording medium. In this case, the support substrate is generally called 'light transmission substrate'. A thickness of the support substrate is set to about 1.1 mm in the CD type optical recording medium and to about 0.6 mm in the DVD type optical recording medium. Furthermore, a protective layer is disposed at an opposite side to the light transmission substrate as viewed from the reflective layer. The DVD type optical recording medium further includes a bonding layer and a dummy substrate having a thickness of about 0.6 mm, in addition to the protective layer.
Meanwhile, a so-called next-generation type optical recording medium, in which a laser beam in the blue wavelength region is used, is an optical recording medium in which a laser beam is irradiated from an opposite side from the support substrate. A light transmission layer, which serves as an optical path of the laser beam, is disposed at an opposite side to the support substrate as viewed from the reflective layer (see JP-A No. 2000-11453). In this case, a thickness of the support substrate is set to about 1.1 mm, and a thickness of the light transmission layer is set to about 0.1 mm.
As such, in the read only optical recording medium according to the related art, the reflective layer needs to be provided on the support substrate. This requires a vacuum process using a sputtering device during the manufacturing process. However, the vacuum process generally is high in manufacturing cost, but relatively low in production efficiency. Therefore, in order to reduce the manufacturing cost and to enhance the production efficiency, it is preferable that the read only optical recording medium is manufactured, without using the vacuum process.

Optical recording medium and method of manufacturing the same


A method for the treatment of bone marrow edema in a mammal comprising administering an effective amount of a polysulfated polysaccharide including salts thereof, to a mammal in need of such treatment.

Bone marrow edema (BME) is a common multifactorial disorder which can occur in isolation and in association with several other medical conditions such as bone fractures, chronic use of steroid therapies (hypocortisonism), alcohol abuse, activated protein C (APC) resistance, prothrombin mutations or hyperhomocysteinaemia and rheumatoid arthritis. However, the appearance of bone marrow lesions in subjects with no known pre-existing disorders normally associated for bone marrow lesions has led to the classification of the condition as bone marrow edema syndrome (BMES). These types of BME are readily identified using magnetic resonance imaging (MRI) and are generally, but not invariably, accompanied by pain at rest and on undertaking physical activities [1-5]. Bone marrow edema has also been described as bone bruising, bone marrow contusions or bone marrow lesions and is frequently associated with a previous traumatic injury. For example 80% of patients who had sustained an acute anterior cruciate ligament (ACL) rupture of the knee joint or a similar post-traumatic joint injury exhibits the symptoms of pain emanating from the joint accompanied by regions of decreased signal intensity on T1-weighted images and increased signal intensity on T2-weighted MRI images of the bone marrow spaces within the joint. Such MRIs images are consistent with localisation of interstitial fluid at site(s) within the bone marrow and are normally located directly adjacent to the areas where the highest contact injury was sustained [1-8]. With the ACL tears the subchondral bone marrow beneath the lateral femoral condyl and the posterior-lateral tibial plateau show the most significant MRI signals but other sites such as ligament insertion points which are also subjected to high tensional stress are may often be implicated. The size of the BME, as determined by MRI, has been reported to correlate with the intensity of activity and rest pain in the patient's knee joint. Moreover, it was noted from MRI follow-ups that a reduction in the size of the lesions was generally associated with a decrease in joint pain [1-8].
Although MRI is clearly the most reliable non-invasive methodology for the diagnosis of BME there is still ongoing debate as to the most appropriate MR pulse signals that would optimize the assessment of BME and achieve semi-quantification of its magnitude. This point is significant in regard to correlations of BME with indices of pain and joint function and how these parameters respond to various modalities of medical treatments. In a recently published study [9] the semi-quantitative assessment of subchondral BME lesions and subchondral cysts was compared using intermediate-weighted (IW) fat-suppressed (fs) spin echo and Dual Echo Steady State (DESS) sequences on a three Teslar (3 T) MRI instrument. This investigation showed that the IW fs sequence identified more subchondral BME lesions and better qualified the extent of their size. While the DESS sequence improved the differentiation of subchondral BME lesions from subchondral cysts, the IW fs sequence was considered superior for the determination of lesion size [9]. The future application of intermediate-weighted (IW) fat-suppressed (fs) spin echo signal analysis coupled with higher resolution MRI instrumentation will undoubtedly serve to improve the quantification of BME and demonstrate the ubiquity of these lesions as the underlying cause of pain and functional disability in acute musculoskeletal disease and disorders.
In this respect subchondral or osteochondral injuries resulting in BME have also been recorded for the hip joint [10,11], foot and ankle joints [12-13] wrist joints [14] and vertebral bodies of the spinal column [15]. Interestingly, even low impact mechanical stress across joints can provoke a painful BME as was described for a patient who after a right knee medial collateral ligament sprain was prescribed the use of a lateral shoe wedge to correct for the medial compartment compression. After using the orthotic device for some weeks the patient presented with worsening pain and an increase in MRI lesion intensity. Discontinuation of the use of the insole reduced the pain and eliminated the BME [16].
Subchondral BME is not confined to synovial joints. The pubic symphysis is an amphi-arthrodial joint composed of two pelvic bones connected by a wedge shaped fibrocartilagenous disc. Beneath the interface of the fibrocartilagenous attachment to the bone plate resides the trabecular bone containing marrow. The trabecular bone in response to intense mechanical stresses, particularly tensional/rotational distraction, can undergo fatigue stress injuries leading to microfractures and culminating in bone marrow edema. These types of pelvic injuries have been described collectively as groin pain, sports hernia (misnomer), athletic pubalgia, or osteitis pubis. It is seen most frequently in elite athletes, particularly long distance runners, soccer players, tennis players and Australian Rules football (AFL) players [17-19]. In the AFL studies it was shown that the incidence of pubic BME, as defined by the MRI signal intensities, was 77%. These bone marrow lesions were also associated with other MRI abnormalities including fibrocartilagenous cysts and secondary degenerative changes in the pubic symphysis. The MRI abnormalities correlated with a players past history of groin pain and tenderness of the pubic symphysis as was determined clinically [17]. It is significant that in a recent publication from the AFL it was reported that groin pain (including osteitis pubis) was one of the three most consistent causes of loss of player time in the AFL [20].
As already indicated an increase in interstitial fluid in subchondral bone marrow is an expression of BME. Such subchondral lesions, if untreated, can progress to bone necrosis and trabecular bone fractures and loss (localized osteoporosis) thereby weakening the underlying mechanical support for the overlaying articular cartilage. In addition, the subsequent disorganized repair of the damages subchondral bone structures can lead to thickening and stiffening of the subchondral bone plate rendering it less compliant to mechanical deformation on loading thereby conferring higher localized stresses on the adjacent articular cartilage thus accelerating its degeneration and progression to osteoarthritis (OA) [21, 22]. It would be expected therefore that there should exists a strong association between the topographical locations of subchondral BME and degenerative changes in the adjacent articular cartilage and the progression of OA. Support for this interpretation was provided in a recent study where, subchondral BME (reported as cysts) were detected by T 1-weighted fat suppressed MRI in 47.7% of OA patients at entry. Over a two years follow-up period the severity of the cysts MRI hyper-signal correlated with OA disease progression, as determined by cartilage volume loss in the medial compartment and the risk of receiving a total joint replacement [23]. Since many younger individuals with BME do not present with accompanying radiological or MRI evidence of OA it would seem that cartilage degeneration, which is considered as a characteristic pathological feature of OA joints, may arise as a secondary event to pre-existing BME. This conclusion is consistent with the early studies of Radin and colleagues who postulated that failure of subchondral trabecular bone (as exists in BME lesions) followed by its mechanical stiffening and reactivation of centers of secondary ossification (calcified cartilage) due to the disorganized repair was a primary cause of OA [21,22].
Additional support for the traumatic stress origin of BME or cysts has been provided by a study of racehorses [24]. The proximal metacarpal region of the performance racehorse is a frequent site of lameness. However, the origin of the pain has hitherto been difficult to diagnose precisely. Review of standing MRI images of the proximal metacarpus/distal carpus of a group of lame horses revealed extensive hyper intensity of the T2 gradient echo signals and a decrease in intensity of the T1 images in the third metacarpal bone that was consistent with a pre-existence of BME which from the literature cited herein, provided an explanation for the origin of the lameness [24].
The traditional medical treatments for symptomatic BME are rest and immobilization of the affected joints/anatomical region. The symptoms of pain and joint dysfunction may resolve spontaneously over 3-12 months, however, the quality of life of the patient during this period can be substantially diminished. With post-surgical patients and others who have BME identified by MRI analgesics or non-steroidal anti-inflammatory drugs (NSAIDs) are often prescribed. The rationale for the use of these drugs for this condition is that they will abrogate the symptoms of BME. However, there is no evidence that these drugs can achieve any beneficial effect since they have little or no therapeutic effect on the underlying pathophysiology responsible for BME. In some instances injections of corticosteroids have been used to treat BME, particularly in elite sports persons whose presence on the field of play is considered critical to the outcome of the game. On the basis of a well established literature [25-30] which has shown that NSAIDs and corticosteroids in particular, have negative effects on the metabolism of cartilage and bone, such medications would be contra-indicated as they could hinder the natural tissue healing process. Moreover, corticosteroids can even exacerbate the problem because of their known procoagulant, antifibrinolytic and osteoporotic inducing effects [28-30]. Such pharmacological activities would delay the clearing of thrombi from marrow spaces and arrest new bone deposition within the bone marrow lesion sites.
Heparin and structurally related polysulfated polysaccharides such as pentosan polysulfate, chitosan polysulfate, the fucans etc have been used for a number of years as anticoagulants [31-36]. Pentosan polysulfate (PPS) is a weaker anticoagulant than heparin [31,33,35] but has been used post-surgically and prophylactically as a thrombolytic agent [36]. However, when given via the oral and intrathecal routes, PPS is currently prescribed for the treatment of interstitial cystitis (inflammation of the bladder) [37-39]. PPS has also been proposed as a disease modifying drug for OA [40] and has demonstrated symptomatic relief in patients with OA [41, 42].

Treatment of bone marrow edema (oedema) with polysulfated polysaccharides


A blind hole insert fixing device is configured for fixing a number of blind hole inserts. The blind hole insert fixing device includes a hollow housing defining a cavity and an engagement member received in the cavity. The housing includes a first inner surface and an opposing second inner surface in the cavity. The engagement member includes a body portion, a number of spring portions, and a number of engagement portions conforming to the blind hole inserts. The spring portions and the engagement portions are located at opposite sides of the body portion. The spring portions abut against the first inner surface. The engagement portions and the second inner surface cooperatively form a number of receiving spaces for receiving the blind hole inserts. The spring portions are configured for applying a force to the body portion in a direction away from the first inner surface.

1. Technical Field
The present disclosure relates to optical technology and, particularly, to a blind hole insert fixing device used in an optical connector molding die.
2. Description of Related Art
Optical connectors are preferred for use in data transmission between electronic devices due to their high transmission speed and signal integrity. An optical connector includes a number of blind holes for precisely receiving optical fibers and a number of lenses aligned with the optical fibers. When the optical connector is assembled, each optical fiber is inserted into a corresponding blind hole in front of a corresponding lens and fixed in a predetermined position by ultraviolet-curable glue.
Generally, the optical connector is molded by an optical connector molding die. The optical connector molding die includes a mold body and a number of blind hole inserts. After the blind hole inserts are coupled with a fixing device, the blind hole inserts with the fixing device are then inserted into the mold body. However, if the blind hole inserts are coupled with the fixing device by a interference fit, the blind hole inserts are easily broken. If the blind hole inserts are coupled with the fixing device by a clearance fit, the blind holes cannot be aligned with the lenses after the optical connector is molded. As a result, the transmission accuracy and efficiency of the optical connector decreases.
Therefore, it is desirable to provide a blind hole insert fixing device used in the optical connector molding die, which can overcome or at least alleviate the above-mentioned problems.


Described herein is a method of calibrating displays (or printers) using Natural Language-based commands. The exemplary method provides an easy-to-use solution to the common methods of color calibrating a display. Instead of using sliders or manual controls for the individual dimensions of a three-dimensional color problem, the user is able to make adjustments via natural language commands, such as “make reference patch less purple.” The method does not require the user to understand color mixing technology when making separate R, G, and B adjustments to match a specified patch. A user can easily express the necessary color adjustment in natural language terms, making the process simpler and faster.

The embodiments disclosed herein relate to a color calibration system, and, more particularly, to natural language-based systems for color calibration of displays.
By way of background, each color display device (e.g., CRT monitor, flat panel LCD, etc.) typically exhibits its own unique color characteristics and tone response. Unless these characteristics are corrected for, poor image quality can result, and/or the same image may reproduce differently on different devices. Color calibration is a means to correct for such display characteristics. The aim of color calibration is to measure and/or adjust the color response of a device (input or output) to establish a known relationship between the device color signals and a standard color space. Color calibration is a requirement for all devices taking an active part of a color managed workflow.
Many color calibration techniques exist, most of which require a measurement device, such as a colorimeter or spectrophotometer, in conjunction with a color profiling application. To suit the more casual/novice user, a class of measurement-free techniques also exist, which rely upon simple visual color matching tasks using standard graphical user interface (GUI) widgets such as sliders and knobs.
There exists, however, a need for a simpler alternative to the common methods of color calibrating a display that does not rely on using sliders and/or manual controls for the individual dimensions of a three-dimensional color problem.

Language-based color calibration of displays


The parking assist system assists the maneuvering for moving a vehicle to a reverse start position, then moving it in reverse from the reverse start position to a predetermined parking position in a manner as follows. A parking target setting section sets a parking target position corresponding to the predetermined parking position, based upon a parking reference detected based on image data captured from the scene around the vehicle. A parking path calculating section sequentially calculates a parking path from a present position of the vehicle to the parking target position, in the course of forward movement along a forward path. A parking path determining section determines whether an effective parking path has been established or not, based upon result of calculation by the parking path calculating section.

A parking operation for parking a vehicle generally involves steering and reverse maneuvering in a small space, thus requiring relatively high maneuvering skill. Then, in order to alleviate the trouble for the diver during parking operation, various types of parking assist systems and maneuvering assist systems have been proposed. Patent Document 1 identified below discloses an invention relating to a parking assist system for assisting a maneuvering operation including a forward movement to a reverse start position and subsequent reverse movement with steering to park the vehicle at a predetermined parking position.
A driver of a vehicle mounting this parking assist system, in order to confirm an empty parking space, stops the vehicle temporarily at a position where the driver can see this parking space substantially directly laterally from the driver's seat. After this temporary stop, the driver maneuvers the vehicle forward, along an arcuate path toward the reverse start position. Being "triggered" by this temporary stop, the parking assist system calculates a moving amount of the vehicle moved forward toward the reverse start position. Then, the driver stops the vehicle at a position when the driver determines, by visual estimation, the vehicle has reached a position where the turning of the vehicle is possible enough. Then, the driver switches the shift lever into reverse. Upon detection of completion of this switching of the shift lever, the parking assist system calculates a parking target position and a guiding path. More particularly, the system effects image recognition of a white line(s) indicative of the parking space and then determines the parking target position, based upon the result of this recognition. The system then calculates the guiding path, based upon this parking target position and the position of the vehicle stopped at the reverse start position.    Patent Document 1: Japanese Patent Application "Kokai" No. 2006-175918 (see paragraphs Nos. 38-51, etc.)


An apparatus for providing optical black and offset calibration for an array signal comprising a sequence of voltage levels corresponding to a sequence of voltage samples of charge coupled devices arranged in an array. The apparatus includes a correlated double sampler adapted to receive the array signal and provide as an output a modified array signal comprising a sequence of first corrected output voltage levels. A programmable gain amplifier receives the modified array signal and provides as an output an amplified modified array signal comprising a sequence of second corrected output voltage levels. An analog to digital converter receives the amplified modified array signal and provides as an output a sequence of digital values. A digital signal storage device stores a digital value corresponding to a desired optical black level. A digital to analog converter stores a correction value corresponding to a determined correction and compensates the amplified modified array signal, based on the correction value, for variations from a desired black level. A correction digital circuit determines an average value corresponding to an average of a plurality of the digital values, subtracts that average value from, and adds a previously stored correction value to, the digital value to determine a current correction value. The current correction value is provided as the current correction value to the digital to analog converter for use thereby.

The present invention relates generally to electronic circuits and, more particularly, to a charge coupled device, which provides optical black and offset correction.
FIG. 1 illustrates, in block diagram form, a charge coupled device (CCD), which is an integrated array of photocells used in digital imaging. The analog front end of a CCD generally consists of three main elements: a correlated double sampler (CDS), a programmable gain amplifier (PGA), and an analog to digital converter (ADC).
For each CDS output, two CCD outputs are sampled (FIG. 2a). The first sample is taken during reference, and the second sample is taken during video signal. The difference is the corresponding CDS output. In this way, low frequency noise of the CCD signal is canceled.
As shown in FIG. 2b, a dark cell does not produce a zero differential output. This is due to the dark currents of the photocells, and the effect may vary from line to line in a frame. This dark current value will be referred as optical black level in this text. Due to the optical black level, and the internal offsets of all amplifiers used in the CDS, PGA and ADC, the resulting ADC output for a dark cell will not be zero. As can be seen from FIG. 1, the CDS offset and the optical black level will also be multiplied with the PGA gain. In order to achieve the ideal dynamic range for the signal (FIG. 2b), the black level and the offsets have to be canceled.
There are shortcomings in the currently known methods for canceling the offsets and black levels. In switched capacitor amplifiers, the conventional way to cancel the offset is accomplished by putting the amplifier in unity gain feedback during sampling phase. This way the input offset is also sampled and canceled during the amplification phase. However, for applications where high closed loop gain and high speed are required, the amplifiers may be optimized for high closed loop gain and may not be stable at unit gain feedback.
In continuous time PGAs, the black level can be canceled by putting the PGA in closed loop feedback during optical black period and feeding back the integrated error to the input of PGA as shown in FIG. 3. However, this scheme needs an accurate reference, and the desired ADC optical black level output will not be programmable by the user. In addition, if the PGA is not continuous time but discrete time (switched capacitor), because of the latency of the PGA continuous time feedback will not be possible.
The circuit arrangement shown in FIG. 4 works with discrete time PGAs, but it will take an unknown number of repetitions (lines) to cancel the offsets and optical black level. Also if the PGA gain is too high, the accuracy of the cancellation will be very poor.
In accordance with the present invention, the sum of the channel offset and optical black level is averaged for a given number of lines and optical black cells per line, and the channel is digitally calibrated to obtain a user programmed ADC output which corresponds to that average.

Optical black and offset correction in CCD signal processing


The present invention relates to a porphyrinogen based sensor having selective binding affinity for an explosive chemical. Upon binding of the target molecule, the porphyrinogen derivative undergoes a detectable adsorption and emission of electromagnetic radiation.

The present invention relates to a porphyrinogen based sensor having selective binding affinity for an explosive chemical. More particularly, this invention is directed to a porphyrinogen derivative possessing cavities which selectively bind the target molecule when the sensor is exposed to environments containing the target molecule. Upon binding of the target molecule, the porphyrinogen derivative undergoes a detectable adsorption and emission of electromagnetic radiation. Moreover, the invention relates to the formation on a metal surface of a self assembled molecular monolayer (SAM) that exposes the porphyrinogen derivative of the present invention to an analyte medium in a manner such that analysis of high sensitivity is obtained.
Chemical sensors must normally fulfill two goals: (1) the development of a specific chemical recognition element that allows a molecule, or class of molecules, to be identified, and (2) a means of signal transduction in which the presence of the molecule causes a measurable change in a physical property of the material. Although these goals are not always separable, the successful design of chemical sensors requires that both is being satisfied. Most transduction approaches are based on optical, resistive, surface acoustic wave, or capacitive measurements. These well-developed methods dominate largely because of their ease of operation, sensitivity, and cost. The chemical recognition elements in these detectors, however, lag far behind.
In a typical sensor fabrication, a solid plastic mass, consisting of the matrix and binder, is prepared which is chemically bound to the polymer/cross-linker matrix and the target molecule. Removal of the target is possible since it is reversibly bound to the binder. The cavity it leaves behind is permanently shaped like the target. Methods for the detection of explosives and explosive residues require complex analytical instruments such as liquid or gas chromatographs coupled with mass spectroscopic or chemiluminescent detection. The associated instrumentation is usually large, expensive, difficult to maintain and requires skilled operators. If laboratory analysis is necessary, extensive documentation is needed for sample transport, increasing the possibility of sample contamination. Immunoassay tests are available for some explosives, but these are cumbersome and have short shelf lives.
A large number of organic pollutants are found in soil. Examples are xenobiotic compounds containing nitro functional groups, which are used in the production of agricultural chemicals, pharmaceuticals, dyes and plastics. Such compounds are also used in mining, farming and they are the main charge in ammunition including landmines. The most common residues contain 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), and associated impurities and environmental transformation products.
Such compounds contaminate their sites of manufacture and storage as well as military installations. In addition, it is estimated that approximately 90% of the mines currently in use are leaking, resulting in the spread of TNT into the soil. Unlike many other pollutants, some of these contaminants have little affinity for soils and rapidly migrate to pollute groundwater. This is a concern as high levels of TNT have been observed to have the potential to inhibit biological activity. Besides the direct consequences of the pollution itself, pollutants of this type may be an indication of the presence of explosives. As landmines are killing and maiming people in former war zones, particularly in remote and poor parts of the world, knowledge of their presence would be of great humanitarian value.
A first requirement in dealing with soil pollution, is an ability to detect polluted sites. Detection systems that are practical and relatively inexpensive are desirable, in order to facilitate their wide-spread use. The currently available detection methods allow for the detection of pollutants, but the methods are both inconvenient and costly.
When referring to information concerning a soil sample each observation relates to a particular location and time. Knowledge of an attribute value, say a pollutant concentration, is thus of little interest unless location and/or time of measurement are known and accounted for in the analysis. The key decisions to achieve cost-effective, accurate site characterizations are the number, location and type of soil samples to be collected, Site characterization errors occur when the sample does not accurately represent the area which the modeling plan assumes it represents. This is a particular problem when the contaminant is distributed non-homogeneously throughout the soil, as occurs with e.g. explosives contamination.
Thus, the characterization of contaminated soils can be expensive and time consuming due to the large number of samples required to effectively evaluate a site.
Present laboratory methods of evaluating environmental samples offer high sensitivity and the ability to evaluate multiple chemicals, but the time and cost associated with such methods often limit their effectiveness. Thus, for many applications there exists a requirement for an economically feasible, robust, and rapid responding system for the mapping of contaminated soils.
Soil contaminated by explosives are traditionally monitored by collecting samples which are analysed in a laboratory by applying various techniques, such as Enzyme Immunoassay and High Performance Liquid Chromatography.
The detection of landmines is normally carried out by sweeping the concerned area using metal-detectors, dogs or manual labour. In military demining, the objective is to clear a minefield as fast as possible using brute force, and usually a clearance rate of 80-90% is accepted. Humanitarian demining, on the other hand, is more difficult and dangerous, as it requires the complete removal of all mines and the return of the cleared minefield to normal use, Today, most humanitarian demining is done using handheld metal detectors finding objects containing metal by utilizing a time varying electromagnetic field to induce eddy-currents in the object, which in turn generates a detectable magnetic field. Old landmines contain metal parts (e.g., the firing pin), but modern landmines contain very small amounts or no metal at all. Increasing the sensitivity of the detector to detect smaller amounts of metal also makes it very sensitive to metal scrap often found in areas where mines may be located. Furthermore, metal detectors, however sophisticated, can only succeed in finding anomalies in the ground without providing information about whether an explosive agent is present or not, One major problem in humanitarian demining is to discriminate between a "dummy" object and a landmine, Identifying and removing a harmless object is a time-consuming and costly process. Dogs have extremely well-developed olifactory senses and can be trained to detect explosives in trace quantities. This technique, however requires extensive training of the dogs and their handlers, and the dog's limited attention span makes it difficult to maintain continuous operations. A number of mine detection techniques are emerging as complements to presently used methods. They include ground penetrating radar (GPR), infrared thermography and advanced metal detectors. A common feature of these techniques is that they detect "anomalies" in the ground but are unable to indicate the presence of an explosive agent. Basically, GPR systems work by emitting a short electromagnetic pulse in the ground through a wideband antenna. Reflections from the ground are then measured to form a vector. The displacement of the antenna allows to build an image by displaying successive vectors side by side. High frequencies are needed to achieve a good spatial resolution, but penetration depth of electric fields being inversely proportional to the frequency, too high frequencies are useless after some centimeters.
Hence, the choice of the frequency range is a trade-off between resolution and penetration depth. Although the detectors can be tuned to be sensitive enough to detect the small amount of metal in modern mines, this is not practically feasible, as it will also lead to the detection of smaller debris and augment the false alarms rate.
WO0177664A2 discloses a so-called molecularly imprinted polymeric explosives sensor. The sensor possesses selective binding affinity for explosives, such as 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitrobenzene (TNB). The polymeric sensor incorporates a porphyrin unit which undergoes a detectable change in absorption and/or emission of electromagnetic radiation when the polymer is exposed to explosives. However, the document does not disclose the tetra-TTF calix[4]pyrrole used in the present invention.
WO03031953A2 discloses a method and apparatus for sensing nitroaromatics. The subject method can utilize luminescent, for example fluorescent and/or electroluminescent, aryl substituted polyacetylenes and/or other substituted polyacetylenes which are luminescent for sensing nitroaromatics. In a specific embodiment, the subject method utilizes thin films of fluorescent and/or electroluminescent aryl substituted polyactylenes and/or other substituted polyacetylenes which are fluorescent and/or electroluminescent. The document does not disclose the tetra-TTF calix[4]pyrrole used in the present invention.
WO0177650A1 discloses a method for detecting an analyte in a sample, using surface enhanced (resonance) Raman scattering (SE(R)RS) detection, comprising the steps of a) mixing the sample with a reagent such that any analyte present in the sample reacts with the reagent thereby forming a derivatised analyte, wherein the derivatised analyte comprises a chromophore; b) mixing said derivatised analyte with a SE(R)RS active substrate so as to adhere the derivatised analyte thereto; and C) detecting the derivatised analyte by way of SE(R)RS detection whereby any derivatised analyte detected may be correlated with analyte present in the sample. Examples of analytes which may be detected include, aldehydes, amines, explosives, drugs of abuse, therapeutic agents, metabolites and environmental pollutants. The sample may be any suitable preparation in which the target analyte is likely to be found. However, the sample may conveniently be in solution or transferred to a solution before reacting with the reagent. Thus, for example when detecting explosives or drugs of abuse, a sample of air or breath respectively, may be taken and any target analyte absorbed onto a suitable substrate. Thereafter, any target analyte may be removed from the substrate by washing with a suitable solvent, such as dimethylformamide (DMF), acetone or tetrahydrofuran (THF). For example, in the determination of TNT or RDX from the vapour phase, the vapour can first be collected on a suitable material such as tenax and a small amount of solvent washed through the material to produce a small amount of explosive in solution. The preferred solvent for this purpose is dimethylformamide.
WO0026638A1 discloses a sensor for detecting an analyte in a fluid comprising a substrate having a first organic material and a second organic material that has a response to an analyte. The sensor has information storage and processing equipment, and a fluid delivery appliance. This device compares a response from the detector with a stored ideal response to detect the presence of analyte. Methods for use for the above system are described where the first organic material and the second organic material are sensed and the analyte is detected. The method provides for a device, which delivers fluid to the sensor and measures the response of the sensor with the detector. Further, the response is compared to a stored ideal response for the analyte to determine the presence of the analyte. In different embodiments, the fluid measured may be a gas, a liquid, or a fluid extracted from a solid. Eventhough the document mentions the applicability of sensor substrates comprising polymers, such as poly(anilines), poly(thiophenes), and poly(pyrroles), there is no suggestion that the specific tetra-TTF calix[4]pyrrole envisaged by the present invention will be applicable for the sensing of TNT.
US20040234958A1 discloses a method for detecting an analyte in a sample using surface enhanced (resonance) Raman scattering (SE(R)RS) detection, comprising the steps of a) mixing the sample with a reagent such that any analyte present in the sample reacts with the reagent thereby forming a derivatised analyte, wherein the derivatised analyte comprises a chromophore; b) mixing said derivatised analyte with a SE(R)RS active substrate so as to adhere the derivatised analyte thereto; and c) detecting the derivatised analyte by way of SE(R)RS detection whereby any derivatised analyte detected may be correlated with analyte present in the sample.
Considerable effort has been focused on the preparation of supramolecular host systems with the capability of recognizing specific chemical species through weak, noncovalent interactions. The incorporation of redox-active components into host molecules is one means of enhancing the guest recognition process via, for instance, increased donor-acceptor interactions. In this context, the use of tetrathiafulvalene (TTF) appears particularly attractive. To date, a number of TTF-containing systems have been synthesized to study host-guest binding events. However, in almost all cases, only weak interactions were observed with neutral guests.
The present inventors have published a paper (J. AM. CHEM, SOC. 2004, 126, 16296-16297) disclosing one of the porphyrinogen derivatives of the present invention, namely the compound of claim 1, which has been excluded from protection (tetra-TTF calix[4]-pyrrole 2a). However, the prior art known to the inventors does not disclose the use of tetra-TTF calix[4]-pyrrole for the detection of explosives, e.g. by interaction with TNT.
The present inventors have surprisingly found that tetra-TTF calix[4]-pyrrole as well as the porphyrinogen derivatives of the present invention have superior properties with respect to the sensing of explosive chemicals, such as TNT.


Service continuity when a user equipment (UE) employing local breakout mechanisms at a femto access point (FAP) for a communication session and moves out of the femto coverage area is disclosed. In particular, a network change detection component can be employed to detect when the UE, attached to the FAP, changes its connection from the femto network to the macro network. Further, an active communication session can exist between the UE and a device/service/application on a local Area network (LAN) connected to a FAP, and/or the Internet, which utilizes local breakout at the FAP. When the UE moves out of the femto network, a context management component can be employed to seamlessly resume the communication session, via the macro network.

Femtocells—building-based wireless access points interfaced with a wired broadband network—are traditionally deployed to improve indoor wireless coverage, and to offload a mobility radio access network (RAN) operated by a wireless service provider. Improved indoor coverage includes stronger signal and improved reception (e.g., video, sound, or data), ease of session or call initiation, and session or call retention, as well. Offloading a RAN reduces operational and transport costs for the service provider since a lesser number of end users utilizes over-the-air radio resources (e.g., radio frequency channels), which are typically limited. With the rapid increase in utilization of communications networks and/or devices, mobile data communications have been continually evolving due to increasing requirements of workforce mobility, and, services provided by femtocells can be extended beyond indoor coverage enhancement.
Conventional systems that employ femtocells, transport information (e.g., data and/or voice) from a user equipment (UE) including Internet bound traffic and home network bound traffic, through a landline network to a macro radio access network (RAN). The information is received at the macro RAN and the Internet bound data can be identified and routed to the Internet from the core network, while the home network bound data is directed back to the home network from the core network. This can lead to significant network congestion in the landline network and/or macro RAN. Further, since data sent by the UE is routed to the home network from the wireless core network only after traversing through the landline network, the response time is substantially high. Accordingly, bandwidth utilization in the traditional approach is inefficient and can negatively impact performance and customer satisfaction.

This patent is subject to a terminal disclaimer.

Service continuity during local breakout in a femtocell


A macrocell base station controls to reduce interference between cells by a downlink signal of the macrocell base station with specific timing, the interference which a downlink signal of a low transmission power cell suffers for a wireless terminal. A low transmission power cell base station decides measurement timing with which the wireless terminal measures reception quality of the low transmission power cell based on information about the specific timing, and sends a setting message including a parameter according to the measurement timing to the wireless terminal. The wireless terminal measures reception quality with the measurement timing indicated by the parameter, and when the wireless terminal satisfies a condition for executing an event based on the measured result, the wireless terminal sends a reception quality measurement message including information indicating that the measurement is made with the measurement timing to the low transmission power cell base station.

The standards development organization 3GPP (The 3rd Generation Partnership Project) has promoted standardization of LTE-Advanced (Long Term Evolution Advanced: LTE-A) as next-generation wireless communication standards compatible with LTE (Long Term Evolution). The LTE-A has examined a wireless IF (Interface) for efficiently covering a local area of indoor facilities etc. in which a high volume of traffic is intensively generated in addition to cell arrangement centered on a conventional macrocell. With this, a heterogeneous network (HetNet) in which a low transmission power cell (also called an "LPN (Low Power Node)") such as a pica-cell or a femto-cell is arranged inside a macrocell has been examined. A HetNet environment will hereinafter be described using the pica-cell as the low transmission power cell.
The HetNet environment is provided with a macrocell base station for building a macrocell, and a pico-cell base station for building a pico-cell inside the macrocell. In addition, frequencies respectively used by the macrocell base station and the pico-cell base station are desirably the same in view of efficient use of the frequency in the HetNet environment. Since the macrocell base station covers a range wider than the pico-cell base station, its load is relatively high. Consequently, a load of the macrocell base station is desirably distributed to the pico-cell base station in order to reduce the load of the macrocell base station in the HetNet environment.
One art for implementing load distribution of the macrocell base station includes "Range Expansion" (see Non-patent Reference 1). FIG. 16 is a diagram conceptually showing the technical contents of "Range Expansion". According to this art, a wireless terminal (UE: User Equipment) connected to a pico-cell located in the pico-cell edge periphery maintains connection to the pico-cell, or UE connected to a macrocell is actively connected to a pico-cell. That is, in order to give priority to connection between the UE and the pico-cell, an area in which the UE is connected to the pico-cell is expanded by applying an offset to downlink reception quality of the pico-cell. However, the UE connected to the pico-cell or the UE in which connection to the pico-cell is maintained by the art greatly suffers interference between cells from the macrocell in the environment in which each of the macrocell and the pico-cell uses the same frequency.

Wireless communication system, low transmission power cell base station, macrocell base station, wireless terminal, and load distribution method

PANASONIC INTELLECTUAL PROPERTY CORPORATION OF AMERICA