A solid-state image pickup apparatus employing a frame interline transfer type solid-state image sensor. The operation of a driving circuit is controlled by a controller in such a manner that image pickup charges produced by photosensitive elements are drained in a charge draining section at a drain timing during a vertical blanking period, and image pickup charges produced by the photosensitive elements in an image pickup unit after lapse of a predetermined light exposure period since the drain timing are transferred to a vertical transfer register so as to be transferred by high speed transfer from the image pickup unit to a storage unit during the next vertical blanking period so that the image pickup charges are read out line sequentially during the imaging period via horizontal transfer registers. The apparatus maintains a constant start timing of the effective light exposure period and produces video signals synchronized with external synchronization signals.

This invention relates to a solid state image pickup apparatus employing a frame interline transfer type solid state image sensor and, more particularly, to a solid state image apparatus having the function of a so-called electronic shutter.
A solid state image sensor such as CCD (charge coupled device) image sensor, has advantageous features such that it is free of burning or residual images as compared to an image pickup tube device, it is highly shock-proof, and lends itself to miniaturization of video cameras. In video cameras conforming to the standard television systems, such as NTSC systems employing an interlace scanning system, a CCD image sensor is employed in which image signals from pixels of odd-numbered fields and those from pixels of even-numbered fields are read out alternately at intervals of one-field periods (one-sixtieth of a second in the case of the NTSC system).
The solid state image sensor, such as the above-described CCD image sensor, may be classified, according to the type of the transfer structure used for outputting image pickup electrical charges, into a frame transfer type, interline transfer type and a frame interline transfer type. In the interline transfer type CCD image sensor, for example, one-field image pickup charges, produced by the photosensitive elements, are transferred at intervals of one-field periods to vertical transfer registers by sensor gate pulses so as to be read out line-sequentially from the vertical transfer register via horizontal transfer registers.
On the other hand a so-called progressive scan CCD or PS CCD image sensor, in which a horizontal transfer gate for two horizontal lines is provided so that image pickup signals from pixels of odd-numbered fields and those from pixels of even-numbered fields are read out in their entirety during a one-field period, has been presented for use in high-resolution video cameras, such as in high-vision television systems.
Besides, there is also presented a CCD image sensor of the type having the function of an electronic shutter for controlling effective charge storage periods of the photosensitive elements electronically. With the CCD image sensor having the function of the electronic shutter, a shutter control pulse is applied to its substrate for sweeping out image pickup charges of the photosensitive elements in an overflow drain for controlling the light exposure time, that is the effective charge storage period, as shown in FIG. 4. In this figure, a shutter control pulse .phi.SP.sub.1/1000 which will give an effective charge storage period T.sub.1/1000 of a duration of 1/1000 second, and a shutter control pulse .phi.SP.sub.1/700 which will give an effective charge storage period of a duration of 1/700 second, are shown. Time intervals beginning at t.sub.1 and t.sub.2 and ending at t.sub.0, the time of the first one of the sensor gate pulses .phi.SG, yield effective storage periods T.sub.1/1000 and T.sub.1/700, respectively.
In the conventional CCD image sensor, having the function of the electronic shutter, the end timing of the effective charge storage period or the effective exposure period is the timing .+-. of the sensor gate pulse .phi.SG, such that the end timing of the effective light exposure period is constant for any shutter speed, with the start timing of the effective exposure period being changed with the shutter speeds. Conversely, with shutter control of a mechanical optical shutter in an optical camera employing a halide film, light exposure is started on actuation of a shutter release so that light exposure is terminated at a timing associated with the shutter speed.
The electronic shutter control in the CCD image sensor is related in an inverse fashion with the shutter control in the optical shutter in an optical camera, so that, in a solid state image pickup device employing the CCD image sensor having the function of the electronic shutter for photographing still images, the start timing of the effective light exposure period tends to be delayed with respect to the shutter release operating timing, so that the opportunity of shutter actuation tends to be lost. In industrial application, if it is attempted to actuate the function of the electronic shutter in photographing an object conveyed on a transfer line, the start timing of the effective light exposure period is delayed, thus rendering it difficult to photograph the object reliably.
Besides, with the electronic shutter function in the above-described CCD image sensor, since shutter control is made by applying a shutter control pulse to its substrate, a noise known as a shutter step (step-like fluctuations in substrate voltage caused by electronic shutter operation in each horizontal blanking period) is produced in a known manner at a boundary of the shutter control pulse. Such deterioration in the picture quality is also produced by shutter step when the CCD image sensor is used in a video camera.
The U.S. Pat. No. 4,984,002, assigned to the present assignee, has been proposed for overcoming the aforementioned problem. In accordance with this prior-art system, the time which elapses between application of a trigger signal until the next vertical synchronization signal is issued is controlled for maintaining the constant start timing of the effective exposure interval.
It is noted that the video camera proposed in accordance with the present invention is frequently put to practical application, in which case it is frequently desired to supply external synchronization signals to a video camera for synchronizing video signals thereto.
With the system of the U.S. Pat. No. 4,984,002, since the timing of the next vertical synchronization signal is determined by the timing of the trigger signal, video signals synchronized to the external synchronization signals can not be produced.

Solid state image pickup apparatus with shutter signal and overflow drain


An apparatus and a method for powder bed fusion additive manufacturing involve a multiple-chamber design achieving a high efficiency and throughput. The multiple-chamber design features concurrent printing of one or more print jobs inside one or more build chambers, side removals of printed objects from build chambers allowing quick exchanges of powdered materials, and capabilities of elevated process temperature controls of build chambers and post processing heat treatments of printed objects. The multiple-chamber design also includes a height-adjustable optical assembly in combination with a fixed build platform method suitable for large and heavy printed objects.

Additive manufacturing, commonly known as 3D printing, are widely used to lower cost and risk in manufacturing of prototypes. In particular, powder bed fusion additive manufacturing reduces the amount of raw material used and places a lower burden on the resources and the environment. As more industrial sectors adopt additive manufacturing for product innovation or mass-production tools, limitations of efficiency and throughput remain challenging to overcome. Contemporary powder bed fusion additive manufacturing systems may be operated in a batch-mode style to print an object in a build chamber. Once a print job is completed, interruptions of operations are required for removing the printed object and remaining powders in the build chamber, with a possibility of switching to a different powdered material. Moreover, the intensity of the light source and optical components may need to be adjusted, re-aligned, or re-configured for the new powdered material. This de-powering and activities of re-arrangements consumes a large fraction of overall machine available time, thereby adversely impacting utilization, efficiency, and ultimately the economics of additive manufacturing.

This patent is subject to a terminal disclaimer.

Chamber systems for additive manufacturing


An optical system is disclosed including an optical pickup having a wavefront aberration-correcting element capable of correcting coma aberration and astigmatism, and an optical disc apparatus which uses the optical pickup. The optical pickup includes a laser light source for irradiating an optical disc with a light beam; an objective lens for focusing the light beam on the optical disc; a lens for correcting astigmatism; a second lens for correcting coma aberration; and a photodetector for receiving the light beam reflected from the optical disc. The astigmatism and the coma aberration are corrected independently of each other.

The present invention relates to an optical pickup and an optical disc apparatus having a mounted optical pickup. The problems concerning wavefront aberrations such as coma aberration, astigmatism, and spherical aberration occur when beams of light are focused on an optical disc. JP-A No. 2000-40249 discloses a technique for reducing the wavefront aberrations of the light beams. In the technique of JP-A No. 2000-40249, wavefront aberrations are corrected by assigning a required phase difference to the light beams that pass through a liquid crystal element disposed in the optical path of an optical pickup.
JP-A No. 2002-140831 discloses another technique for reducing wavefront aberrations of the light beams. In the technique of JP-A No. 2002-140831, an aberration-correcting optical system for correcting coma aberration and spherical aberration is disposed in the optical path of an optical pickup.

Optical pickup and optical disc apparatus


This invention relates to the enhancement of feed efficiency and growth rate, and the reduction of fat accumulation to produce better quality meat by administration of an exogenous gene sequence comprising the complementary DNA sequence of growth hormone releasing factor to stimulate the production of the endogenous hormone peptide growth hormone. This invention further relates to methods for producing such gene sequence.

The present invention relates to the administration of an endogenous hormone peptide, more particularly, to the administration of an endogenous hormone peptide with gene-based material to enhance feed efficiency and growth rate of livestock.
There have been many approaches to stimulate the growth rate of livestock and to enhance feed conversion efficiencies. These include the use of antibiotics, chemicals, and the use of biological compounds such as native or recombinant growth hormones (GH) or growth hormone releasing factors (GHRF). Many of these approaches either have side effects or are too expensive to implement in actual farms or ranches.
Although antibiotic supplements have been routinely used to enhance growth performance and feed conversion in the past, their benefits are now diminishing due to improvements in modern farm management and the potential danger of spreading antibiotic resistance to other animals including man.
The earliest attempts in biological enhancement used injections of pituitary extracts, from which the pituitary GH was later isolated and purified.
GH produces a variety of effects on body tissues, ultimately leading to an increase in growth rate and weight gain. In vivo, GH stimulates the synthesis of proteins, the breakdown of fats, and epiphyseal growth. These effects are mediated via the up-regulation of somatomedins, for example insulin-like growth factor I (IGF-I). The production and release of pituitary GH is under the control of two hypothalamic hormone peptides. Inhibition by somatostatin and stimulation by GHRF regulates the plasma GH levels. As animals age, there are deleterious changes in the GHRFxe2x86x92GHxe2x86x92IGF-I axis. Hence in older animals including man, GH production rate decreases, and the IGF-I response to GH and GHRF diminishes. These lead to osteoporosis, decrease of lean muscle, and increasing truncal fat deposits. Therefore pituitary extracted GH has been used to supplement the natural decline in GH and enhance growth. However, such a treatment suffers from the risks of adventitious pathogen transmission. In addition, the major drawback is the high costs involved. Since GH is a protein, it is easily digested by intestinal enzymes and must be administered by injection. Furthermore, GH has to be given daily due to its short serum half-life. This pushes up the cost of treatment, making it feasible only for human therapy.
The development of recombinant DNA technology and the use of microbes such as E. coli to produce mammalian GHs meant that homogenous GH preparations could be produced in large quantities for treatment, thereby reducing the costs. Additionally, recent advances in protein stabilization by engineering substitutions in the primary structure and development of slow release formulations have reduced the frequency of dosing to weekly or bi-weekly. As the costs of treatment lower, it can be used commercially to boost agricultural production. For instance, recombinant bovine GH is currently being used to boost milk production in a third of the United States of America dairy herd.
Treatment of pigs with porcine GH was shown to enhance growth rate, increase carcass protein whilst reducing the proportion of fat. The benefits of porcine GH on pig""s growth performance and the safety and economic aspects involved have been reviewed by Palmer J. Holden (Porcine somatotropin (pST), Biotechnology Information Series (Bio-4), Iowa State University, 1993). Summarizing data from twenty studies, it was reported that porcine GH injected pigs grow 15% faster whilst consuming 21% less feed, with more muscle protein and reduced backfat. However, these gains in productivity are made at substantial costs. Firstly, because of its short serum half-life and rapid clearance from the bloodstream, GH must be injected daily to be effective. Hence pigs must be given up to 4 mg of porcine GH protein per day for the one or two month duration of the finishing period to sustain plasma GH levels and improve growth performance. Thus each pig may eventually require as much as 400 mg of GH. Secondly, high doses may be toxic and have been shown to cause some adverse side effects such as breathing difficulties, as described in the U.S. Pat. No. 5,134,120. Moreover, the treatment regiment so far described in the literature is too labor intensive and traumatic to the animal. Even though U.S. Pat. Nos. 5,015,626 and 5,134,120 describe the use of porcine GH to improve meat quality and enhance weight gain respectively, the current technology in GH peptide-based growth promotants are yet to be economical to apply to commercial farming.
The discovery of the growth hormone releasing factors (GHRF) promised to provide a better method of growth enhancement. GHRF is a peptide hormone secreted by the hypothalamus and specifically stimulates the synthesis and release of GH by the somatotroph cells of the anterior pituitary gland. By stimulating the endogenous production of GH, the effective dose required is much smaller than that of GH, thus providing a more physiologic mode of treatment at potentially lower costs. Nevertheless, to the best of our knowledge, there appears to be still no satisfactory and cost effective treatment for livestock. For example, the use of human GHRF protein injections twice daily to stimulate the growth of sheep was described in EP Pat. No. 0,289,186. However, prolonged injections of the human GHRF induce immune response in sheep with neutralizing antibody formation against the human protein. This lowers the efficiency of such a treatment, and the labor and material costs render this approach uneconomical. Injections of GHRF peptide have been used to produce a more sustained stimulation of production of GH in the pig. Although some trials have shown success in producing a gain in body weight and lower carcass fat content, the same problem of rapid clearance means frequent doses are required. Therefore a new approach to supplement GH levels for growth enhancement is required.
Since it was first demonstrated that intramuscular-injected plasmid DNA vectors are taken up by the skeletal muscle cells and expressed for many months in vivo, skeletal muscle based gene therapy has held great promise for the systemic delivery of therapeutic proteins. This skeletal muscle production of recombinant proteins which can be secreted into the circulation system to reach distant target sites ideally suites the treatment of diseases arising from serum protein deficiencies. Plasmid vectors, although much less efficient in protein expression than viral based vectors, have the advantages of being less likely to be immunogenic and not integrated into the host genome. Therefore, they are generally thought to be safer. On this basis plasmid vectors best suit situations where the therapeutic protein is effective at low concentrations. Thus, injection of plasmid vectors expressing the gene for GHRF may be an ideal method to apply a chronic supplement of GHRF at an effective dose sufficient to enhance growth performance of animals. Furthermore, persistent GHRF production should drastically reduce the frequency of treatment, hence lowering the costs to an economically viable level.
Recently, it was shown that a plasmid containing human GHRF (hGHRF) cDNA under the control of the chicken minimal skeletal xcex1-actin promoter is able to produce an elevation in plasma GH levels when injected into the mouse muscle (Draghia-Akli et al, Nature Biotechnology, 15, p1285-1289). Furthermore, growth enhancement of approximately 15% was reported at 3 weeks post injection. However, their methods elicited an immune response as evidenced by the increasing serum levels of neutralizing anti-hGHRF antibodies at 21 and 28 days after hGHRF gene injection. It has been shown that the limiting factor in the level of in situ gene expression from injected plasmids is the extremely low degree of uptake of plasmid DNA by the muscle fibers. To improve the level of hGHRF expression, Draghia-Akli and co-workers first injected bupivacaine, a well known myotoxic substance, before injecting the plasmid DNA into the regenerating muscle. Although this has been shown to improve the level of expression by increasing plasmid uptake in the muscle fibers, it is neither a desirable nor an acceptable technique to apply in farm animals reared for human consumption.
It is therefore an object of this invention to provide a cost-effective approach to stimulate the growth rate of animals, particularly livestock animals, and to enhance feed conversion efficiencies through the administration of an endogenous hormone peptide GHRF. As a minimum, it is an object of the present invention to provide the public with a useful choice.
Accordingly, there is provided a method of enhancing feed efficiencies and/or growth rates and/or reducing fat accumulation of animals comprising administration of endogenous hormone peptide GHRF by an exogenous gene sequence to stimulate the production of GHRF, and said exogenous gene sequence comprises a DNA sequence encoding a promoter for gene expression, a complementary DNA (cDNA) sequence encoding a GHRF signal peptide, and a cDNA sequence encoding GHRF.
Among the particularly preferred embodiments of this invention are variants of the promoter being an actin promoter. In accordance with certain preferred embodiments of this invention, the actin promoter is a skeletal actin promoter. The DNA sequence encoding a skeletal actin promoter particularly prefers comprising a full set of DNA sequence of the skeletal actin promoter.
In accordance with another preferred embodiments of this invention, the exogenous gene sequence further includes a DNA sequence encoding the three prime (3xe2x80x2) untranslated polyadenylation signal-containing region of the gene of the promoter or GHRF.
In accordance with yet another preferred embodiments of this invention, the exogenous gene sequence further includes a DNA sequence encoding a gene for antibiotic resistance.
The GHRF and its signal peptide encoded by said cDNA sequences can be the corresponding natural or recombinant or synthetic, or biologically active fragments or their analogues with similar activities. It is a particularly preferred embodiment of this invention that the DNA sequence of the promoter, the cDNA sequence encoding a GHRF signal peptide, and the cDNA sequence encoding GHRF are species specific.
The said exogenous means to stimulate the production of GHRF being a DNA sequence is preferably mixed with a suitable carrier to be administered subcutaneouly. In accordance with certain preferred embodiments of this invention, the exogenous DNA sequence is administered via intramuscular route.
The said exogenous means to stimulate the production of GHRF being a DNA sequence given per animal is preferably between the range of 1 to 100 xcexcg per kg body weight of the animal.
It is another aspect of this invention to provide an exogenous gene sequence to simulate the endogenous production of GHRF to enhance feed efficiencies and/or growth rates and/or reduce fat accumulation of animals, wherein the exogenous gene sequence comprise a DNA sequence encoding an promoter for gene expression, a cDNA sequence encoding a GHRF signal peptide, and a complementary DNA (cDNA) sequence encoding GHRF.
It is yet another aspect of this invention to provide a method of manufacturing a medicament to enhance the feed efficiencies and/or growth rates and/or reduce fat accumulation of animals comprises providing a DNA sequence encoding a promoter for gene expression, joining a cDNA sequence encoding a GHRF signal peptide, and joining a cDNA sequence encoding GHRF to form a gene sequence and mixing said peptide with a suitable carrier.
Other objects, features, advantages, and aspects of the present invention will become apparent to those skilled from the following description. It should be understood, however, that the following description and the specific examples, while indication preferred embodiments of the invention, are given by way of illustration only. Various changes and modifications within the spirit and scope of the disclosed invention will become readily apparent to those skilled in the art from reading the following description and from reading the other parts of the present disclosure.

Gene treatment to enhance feed efficiency and growth rate of livestock


A power converter topology is adapted for efficiency according to input voltage, output voltage or output current conditions. Topology adaptation is achieved by control responsive to the input and output operating conditions, or to one or more external control signals. Transition between any two topologies is implemented by pulse width modulation in the two switches in one of two bridge legs of a full bridge converter. When transitioning from full-bridge to half-bridge topology, the duty ratio of one switch in one leg of the full bridge is increased, while simultaneously the duty ratio of the other switch in the same leg is reduced until one switch is continuously on, while the other switch is continuously off. The transition from the half-bridge to the full-bridge topology is accomplished by modulating the same switches such that, at the end of the transition, both switches operate with substantially the same duty cycle.

1. Field of the Invention
The present invention relates to power converters that can efficiently operate with a wide input-voltage or output-voltage range.
2. Description of the Related Art
In many applications, power conversion circuits are required to operate with a wide input or output voltage range. For example, most single-phase AC/DC power supplies in today's computer and telecommunication ("telecom") power systems must operate in the universal AC line range between 90 VRMS and 264 VRMS and must provide a regulated output voltage. Typically, telecom AC/DC power supplies provide a regulated output voltage between 42 V to 58 V, while power supplies for desktop, networking, and server applications provide a single constant output voltage or multiple constant output voltages. However, to further improve energy efficiency, an emerging requirement in server power supplies is a single output voltage selectable from two predetermined levels. Specifically, this new generation of server power supplies with dynamically adjustable output voltage provides a 12V output at full and mid-range loads, and a 6V output at light loads (for light-load efficiency). AC/DC battery chargers are another major class of power converters that operate with a wide input or output voltage range. For example, today's plug-in and battery electric vehicles (EVs) have an output voltage range of 200-450 volts.
There is a trade-off between the input voltage range or the output voltage range and conversion efficiency. Power converters operating in a wide input voltage range or output voltage range exhibit a larger efficiency fall-off than their narrow-range counterparts.
The detrimental effect of a wide input or output voltage range on conversion efficiency is more severe in resonant converters than in pulse-width-modulated (PWM) converters. Generally, resonant converters regulate output voltage by changing switching frequencies. Specifically, in resonant converters designed to provide zero-voltage-switching (ZVS), the switching frequency is increased to maintain output regulation when the input voltage increases or when the output voltage decreases. As a result, these converters suffer from increased switching losses when they operate away from the minimum input voltage or the maximum output voltage. Therefore, resonant converters—including the most efficient series-resonant LLC converter topology—are not suitable for applications with a wide output voltage range. PWM converters that operate at a constant frequency do not suffer from increased switching losses in wide input voltage or wide output voltage applications. Thus, any efficiency drop associated with an output voltage decrease for such converters is primarily due to other factors (e.g., an increased conduction loss resulting from a reduced duty cycle, which increases the RMS current).
The overall efficiency in converters operating in an extremely wide input or output voltage range can be improved by multi-stage conversion. Specifically, a pre-regulator stage can be used to handle wide input voltage variations, and a post-regulator stage can be used to handle the wide output-voltage range. While this approach has been demonstrated to improve efficiency, as compared to a single-stage conversion, it is not preferred as the increased number of components increases circuit complexity and cost.

Power converters for wide input or output voltage range and control methods thereof


A system and method of adjusting an equivalent channel for a downlink in a multiple-antenna communication system is disclosed herein. The system includes at least one user device and a base station having a plurality of analog RF chains, each analog RF chain having a plurality of antennas. The method comprises the base station obtaining equivalent channel information and adjusting the phases of the antennas in order to modify equivalent channel gains from the analog RF chains to the at least one user device, based on the equivalent channel information.

There are various types of communications systems that can be used to communicate data wirelessly. An example of such a communication system is the multiple input multiple output (MIMO) communication systems. In MIMO systems there are multiple antennas at the transmitter end and at the receiver end. A further example is the massive MIMO communication system in which a very large number of antennas are used.
Improvements in wireless communication systems are desirable.

System and method for massive MIMO communication


An adjusting device for adjusting the relative angular difference between two rotating members having a guide arrangement between a driving member and a rotating follower. The guide arrangement will allow the rotating driver to perform relative axial movement relative to the rotating follower to change the relative axial and angular difference between the rotating driver and the rotating follower.

All car manufacturers around the world are continuously seeking a totally-satisfactory car which may run smoothly at low speed driving and run powerfully at high speed driving. Although the diesel engine provides better performance at low speed, its performance at high speed is comparatively inferior. On the other hand, the gasoline engine is relatively good with regard to its performance at high speed and inferior at low speed.
Until now there has been no engine which can provide good performance consistently at different speeds--i.e., high, medium and low speed. It is chiefly because the opening time of the valves and the ignition timing fail to match up with the change in the speed of revolution of the engine.
Every car manufacturer knows that, to have an engine with good performance at high speed requires the advance of both the ignition timing and the opening of the air intake valve because the higher the speed the greater amount the ignition is advanced. Advancing the air valve at high speed allows a sufficient amount of intake air and facilitates effective exhaust of the waste gas in the cylinder. To match the advancement of ignition timing, the engine will become power driving at high speed. To attain better performance of the engine at low speed, the advancement of ignition timing has to be reduced and the opening of the air valve should not be increased so that the explosion stroke in the cylinder will be extended to increase the thrust force of the piston resulting in a large increase in torsion when driving at low speed.
As a matter of fact, the time of the opening of the intake valve and the exhaust valve, and the timing of the ignition have to be adjusted properly with the speed of revolution of the engine so as to achieve an engine with good performance at high speed, medium speed and low speed respectively. Although there are centrifugal ignition advances, and vacuum ignition advances, there is no such kind of real mechanism for the advancement of the opening of air valve.
As for the multiple-valve engine, the increase in the numbers of air valves only promotes the amount of intake and exhaust, rather than advancing the opening of both the intake and exhaust valves.
Therefore one object of the present invention is to provide an adjusting device for the relative angular difference between two rotating members, which is able to adjust the relative angular difference between the rotating driver and one or more rotating followers respectively. The present device can be mounted between the cam shaft of the air valve and the cams of various air valves as well as the cam shaft of the air valve and the driving shaft of the distributor to coordinate the adjustment of the time of the opening of the air valve and the ignition timing to allow the engine to obtain best torsion output and smoothness of driving at high speed, medium speed and low speed.

Adjusting device for adjusting the instantaneous relative angular difference between two rotating members


A method of preventing gas coning or fingering from a gas cap in an oil producing well is provided. A silicate solution and a delayed activator are injected into the gas cap under conditions such that the activator causes the silicate to gel after a predetermined period of time to form a substantially impermeable zone or layer above the oil bearing formation to prevent gas from flowing into the oil well during production.

The present invention relates to methods of preventing gas coning and gas fingering in high temperature hydrocarbon bearing formations. More particularly, the present invention relates to methods of preventing gas coning or fingering using high temperature sealants.
Many hydrocarbon bearing formations contain gas as well as oil. Because of its lower density, the gas accumulates at the top of a reservoir and forms what is often called a gas cap.
Usually it is desirable to preferentially produce oil from a formation containing both gas and oil. This is accomplished by cementing the casing through the formation and perforating it only opposite the oil zone. However, there is often a considerable amount of vertical permeability whereby gas is drawn down into the oil bearing portion of the formation as the pressure is reduced when oil flows into the production tubing. When this occurs around the well bore to create an inverted cone shaped volume, it is generally referred to a gas coning. Gas can also preferentially flow through areas of higher permeability such as fractures. When gas flows through these areas into the oil bearing portion of the formation, it is often referred to as fingering.
A number of methods have been developed in an attempt to reduce or solve the problem of gas coning. One such method is disclosed in U.S. Pat. No. 2,713,906. The method disclosed in this patent attempts to selectively block the formation approximately at the plane of the interface between the normal upper surface of the liquid oil and the overlaying gas cap. This blocking or plugging is achieved by localized, selective deposition of an asphaltic or bituminous material at the liquid-gas interface. This is accomplished by injecting asphaltic material into the formation just below the liquid surface as an asphalt-rich solution in an organic solvent or diluent compatible with the reservoir oil and from which the asphaltic substance is precipitated by contact with the reservoir gas. A sufficient amount of the solvent-asphalt solution is injected to displace the reservoir oil a substantial distance in a radial direction from the well bore at the oil-gas interface. The solvent-asphalt solution thereby makes contact with the reservoir gas at the interface and the asphalt is deposited from the solution.
Another method which has been proposed to prevent or reduce gas coning involves the injection of foams into the hydrocarbon bearing formation. Such a process is disclosed in U.S. Pat. No. 3,616,858. According to this process, an MQ-type silicone is pumped into the hydrocarbon bearing formation. The silicone is a foaming agent which can simply be pumped down the well into the entire oil producing formation or it can be pumped into a disk-shaped volume at the oil-gas interface by isolating a portion of the well with packers. As gas tries to flow through the silicone, the gas causes the silicone to foam, thus inhibiting further flow.
Still a further method of preventing gas coning is disclosed in U.S. Pat. No. 3,779,315. This method involves the injection of a polymeric solution into the hydrocarbon containing formation at a location lower in elevation than the gas cap. Preferably, gas is removed from the gas cap during injection to facilitate movement of the polymeric material up into the zones of high permeability between the gas cap and the lower oil bearing portion of the formation. Preferred polymers include partially hydrolyzed polyacrylamides, polysaccharide carboxylmethyl cellulose and polyethylene oxide. Water is at least intermittently injected into the gas cap above the deposited polymer layer as oil is subsequently produced from the bottom of the formation.
Other attempts have been made to reduce gas coning and fingering using technology developed to prevent water coning in hydrocarbon bearing formations. For example, INJECTROL.RTM.U, a product of Halliburton Services, has been injected into low temperature wells to prevent gas coning. INJECTROL.RTM.U is a sodium silicate solution which uses urea as an activator. However, it was discovered that INJECTROL.RTM.U with urea set too fast to be used in high temperature wells since there was not sufficient time to pump in enough sealant to get deep penetration.
While these methods have experienced some success they each have their limitations and disadvantages. Accordingly, it would be an advancement in the art to provide a method for preventing gas coning and fingering in which the substance being injected had a substantial depth of penetration to provide a large area of low permeability. It would be a further advancement to provide a system that was thermally stable at higher temperatures. Such a method is disclosed and claimed herein.

Method of preventing gas coning and fingering in a high temperature hydrocarbon bearing formation


An inventive temperature-compensated crystal oscillator has a construction such that a crystal oscillator element (5) is accommodated in a container (1) and an IC element (7) for controlling an oscillation output on the basis of the oscillation of the crystal oscillator element (5) is mounted on a lower surface of the container (1). A plurality of electrode pads (10) at least including plural crystal electrode pads connected to the crystal oscillator element (5), plural writing control electrode pads, and an oscillation output electrode pad, a ground electrode pad, a power source voltage electrode pad and an oscillation control electrode pad connected to surface mounting external terminals are arranged in a matrix configuration of m rows×n columns (wherein m and n are natural numbers not smaller than 2) in an IC element mounting area. The IC element (7) is electrically connected to the electrode pads (10). The temperature-compensated crystal oscillator is excellent in IC element bonding reliability, and meets the need for the size reduction of the entire structure.

1. Field of the Invention
The present invention relates to a temperature-compensated crystal oscillator for use in an electronic device such as a mobile communication device.
2. Description of the Related Art
Conventionally, temperature-compensated crystal oscillators are employed in electronic devices such as mobile communication devices.
A conventionally known temperature-compensated crystal oscillator has a construction such that a container 23 is bonded onto an upper surface of a planar substrate 21 having a plurality of external terminals 22 provided on a lower surface thereof as shown in FIGS. 21(a) and 21(b). A crystal oscillator element 24 is accommodated in the container 23. An IC element 26 which controls an oscillation output on the basis of the oscillation of the crystal oscillator element 24 is provided in a cavity 25 defined by a lower surface of the container 23 and an interior surface of a frame base 27 attached to the lower surface of the container 23.
The container 23 is adapted to hermetically seal the crystal oscillator element 24 accommodated therein without communication with the atmosphere. The container 23 includes a base plate composed of an electrically insulative material and a seal ring 31 attached to an upper surface of the base plate. The crystal oscillator element 24 is attached to the upper surface of the base plate in the seal ring 31. A metal lid 32 is welded to an upper surface of the seal ring 31 by seam welding(resistance welding), whereby the space in which the crystal oscillator element 24 is accommodated is hermetically sealed.
In general, the base plate of the container 23 and the frame base 21 are integrally formed of a ceramic material such as glass-ceramic. Interconnection conductors are provided in and on the base plate and the frame base. A conventionally known ceramic green sheet laminating method is employed for the formation of the base plate and the frame base.
An IC element 26 mounting area on the planar substrate 21 is illustrated as having a rectangular shape by a solid line in FIG. 22. As shown, a plurality of electrode pads 28 respectively connected to electrodes of the IC element 26 are arranged in two rows as stated, for example, in Japanese Unexamined Patent Publication No. 2001-291742. Five electrode pads are arranged in one of the two rows, and six electrode pads are arranged in the other row.
A flip chip IC element 26 having a plurality of connection pads is employed as the IC element 26. Where the flip chip IC element 26 is mounted on a lower side of a mounting base 23, the connection pads of the IC element 26 are first brought into contact with the corresponding electrode pads 28 in the IC element 26 mounting area with the intervention of electrically conductive bonding members such as of a solder, and then the electrically conductive bonding members of the solder are heat-melted at a high temperature for the mounting of the IC element 26 on the mounting base 23.
However, the plan area of the aforesaid temperature-compensated crystal oscillator is reduced to 7 mm×5 mm, to 5 mm×3 mm, and further to 3 mm×2 mm. With the size reduction of the oscillator, there is an increasing demand for the size reduction of the IC element 26. As a result, the pitch of the electrode pads 28 should be reduced with the need for the reduction of the IC element 26 mounting area. This reduces the bonding reliability, leading to limited flexibility in routing interconnection conductors 29 connected to the electrode pads 28.
In order to flatten the oscillation output by oscillation control by means of the IC element 26 according to the specific temperature characteristic of the crystal oscillator element 24 of the temperature-compensated crystal oscillator, the specific temperature characteristic of the crystal oscillator element 24 should preliminarily be measured before the mounting of the IC element 26. However, the size reduction of the electrode pads makes it difficult to measure the specific temperature characteristic, drastically reducing the productivity.
An advantage of the present invention is to provide a temperature-compensated crystal oscillator which totally has a reduced size and yet maintains and improves the bonding reliability of an IC element.


System and method for performing Unicode matching for comparing and merging similar data objects having Unicode strings that are equivalent yet not exact matches. Unicode characters are characterized by number of strokes, stroke order, radicals, geometry, phonemes in association with input method editor and keyboard characteristics such as location of a character on an IME or keyboard (or number of GUI interface interactions used in entering the character, e.g., via tapping where “a” on a mobile device keyboard takes 1 tap of a key, “b” takes 2 taps). These characteristics associated with code points and IME's/keyboards are utilized to create subdomains for matching and determining “distance” to other Unicode code points (e.g., number of keyboard keys away). Allows for determining whether close, yet incorrect data entry may have taken place. Enables merging of duplicate data objects into master data object where minor differences or spelling errors introduce actually represent duplicate data.

1. Field of the Invention
Embodiments of the invention described herein pertain to the field of computer systems. More particularly, but not by way of limitation, one or more embodiments of the invention enable a system and method for performing Unicode matching for comparing and merging similar data objects having Unicode strings that are equivalent yet not exact matches.
2. Description of the Related Art
Data objects are database entities that represent objects such as products for example. Data objects may be constructed in a database with number fields, string fields and other field types associated with different types of data such as binary large objects or images for example.
Duplicate data objects in databases occur when two or more data objects exist in a database that actually represent the same object. These duplicate data objects have similar, yet slightly different values in one or more fields that make up the database object. Duplicate data objects are created for example via incorrect data entry or merging of systems that contain slightly different versions of data objects. One such scenario occurs when data objects are entered into a database with string fields that have typographic errors, abbreviations, omissions or transpositions for example. Consolidating duplicate data objects preserves data integrity and minimizes costs associated with maintaining duplicate data objects.
Database object string fields hold characters that represent words in a desired language, for example English. English characters may be encoded using the American Standard Code for Information Interchange (ASCII). Checking words for near matches in ASCII encoded strings is relatively easy since the problem domain is so small, i.e., there are only 128 characters and words are built character by character. In other languages where a single data value represents an entire word, there is no previously known method for determining how "close" one word is to another. This is true since the encoding for the word does not include any of the characteristics of the word such as sound, number of strokes, radicals, geometry or any other characteristic that can be utilized to determine how closely related one word is to another. One such measure of how close one word is to another relates to how "far apart" the two words are in an input method editor graphical user interface, whereby a user may erroneously select one word instead of another, e.g., be "off" by one list entry when selecting a given word.
Traditional Chinese for example includes over 40,000 logograms which represent words. Chinese along with other languages are therefore not capable of being encoded in such a small range of values as are alphabet based languages since an ASCII character readily fits in an 8 bit word, while traditional Chinese requires at least two 8 bit words. Furthermore, Chinese using Basic Multilingual Plane (BMP) encoded in UTF-8 requires up to three 8 bit words in binary computer memory. Japanese is another logogram based language. These types of logogram based languages are generally encoded in "Unicode" for storage of text in databases.
Unicode is an industry standard for representing text that enables consistent representation of text regardless of language. Symbols in Unicode are assigned unique "code points". Code points may be represented as binary or hexadecimal values for example. An example code point is written as "U+xxxx" where "xxxx" represents a number associated with the code point, e.g., "U+0065" which represents the letter "e". Encoding a language such as traditional Chinese requires a much larger range of values, or code points when compared to ASCII for example. When checking a particular Unicode code point to determine if it really should be a different word, there is no previously known method to utilized related characteristics associated with the word to determine how close two words are to one another or whether an input error may have occurred for example.
Japanese is another example of a logographic language. Japanese is written using three types of symbols. Kanji symbols include ideographic and pictographic characters adopted from the Chinese language that fit into less than 20 geometric structures. Conceptual words in Japanese such as verbs, adjectives and names for example are generally written using Kanji. Kana symbols are phonetic symbols developed in Japan. Each kana symbol is a phonetic representation of a syllable. Kana is written in one of two ways depending on the type of word it represents, namely hiragana and katakana. Hiragana symbols are utilized in writing native words not written in kanji and inflectional endings of kanji words. Katakana is utilized in writing foreign words. In addition, Romanization of Japanese words is accomplished using 22 roman characters and 2 diacritical marks. Homophones, words sounding alike with different meaning may be represented with different kanji. There are a large number of homophones in Japanese and hence Romanized Japanese is at times difficult to understand even in context. For verbal input methods, homophones present a very real possibility for erroneous data entry. There is no concept of capital versus lowercase letters in Japanese, unlike English. Hence normalization of case in Japanese (for example to all lowercase) before comparison is not possible and hence not needed for comparison purposes. There are two types of Romanization utilized in writing Japanese, Romaji and Hepburn that differ slightly from one another. Although Japanese kanji officially about 2,000 characters, these characters may be mixed with phonetic symbols that make heterographs, i.e., words that are spelled differently but sound and mean the same thing. Erroneous homophone data entry and correct heterograph entry yield data values that may not yield exact spelling matches. Non-exact spelling matches in fields that should be the same signify potential data object merging problems.
Input method editors (IME's) are utilized in entering complex languages into a computer system. Japanese may be entered into a computer in many different ways, including the use of an IME. Use of a Japanese input method editor (IME) on a computer system allows for the selection of characters phonetically, via hiragana and katakana and through use of radicals for example. In addition, Romanized typing of Japanese words on a keyboard or IME is another entry method. In this type of entry, the computer guesses the correct symbol based on the Romanized input and underlines the entry as tentative. Some IME's allow for the entry of a SPACE character to yield a list from which to pick related symbols. Symbols near the correct entry (above or below in the list) may occasionally be accidentally chosen for example. Characters that are close to one another on an IME (next to or above or below the correct symbol in a table) are potential erroneous entry values as a user entering text may select a character near the correct symbol. There are no prior known systems that decompose Unicode code points into related code points based on the type of IME used for data entry.
Chinese may also be entered into computer systems via IME's by breaking up the logograms via structure such as with the Cangjie or Wubi method of typing Chinese, or using phonetic systems such as Zhuyin or Pinyin and selecting possible choices from lists. Since the data entry may be to a closely related erroneous selection, duplicate data objects may result. For example, erroneous selection from a list may result in the entry of a selection that is one logogram away from the desired one. This problem is not unique amongst Japanese and Chinese and is related to any language having a large number of Unicode code points.
Similar issues exist in the entry of other languages such as Korean and the nearly extinct script version of Vietnamese.
When comparing data objects, for example two strings encoded in ASCII, character by character, one word may contain a character that is not in a second word, or the second word may not be found in a dictionary for example. If the rest of the data in each data object compares favorably, then the two objects may actually represent the same data object and hence, may be consolidated. Comparing objects in ASCII is relatively easy since the domain is small (128 characters) and since words constructed in this domain are readily comparable letter by letter.
Comparing strings in Unicode written in languages with small numbers of character sets involves checking for accent marks over characters. For example, comparing strings that include letters having accent marks is performed by transforming single accented characters into corresponding combining sequences. This process is defined as "Unicode normalization". For example, comparing U+00E9 (a latin small letter e with an acute accent mark) involves breaking the letter into two letters, namely U+0065 and U+0301, i.e., "e" and the acute accent mark combining character so that "e" can be compared against the accented version. Unicode normalization is described in Unicode Technical Report UAX 15. Another term for breaking characters with diacritics is "decomposition".
Currently, systems attempting to consolidate data objects that actually represent the same object perform string comparisons with Unicode strings and only find exact matches. Hence only exact copies of data objects can currently be consolidated via existing methods. Hence, current systems are highly inefficient when comparing similar strings when the strings are encoded in Unicode that are not exact matches since the domain is so large. There are no known systems that compare closely related data objects in Unicode, e.g., for large characters sets such as Japanese or traditional Chinese, for consolidation.
There are no known comparison systems that decompose logograms or Unicode representations thereof based on the input method used to enter the Unicode string. For at least the limitations described above there is a need for a system and method for performing Unicode matching for comparing and merging similar data objects having Unicode strings that are equivalent yet not exact matches.


Methods and apparatus for a memory system using a branching point-to-point memory bus architecture are disclosed. In one embodiment, a primary memory controller maintains a point-to-point bus connection with one memory module and that memory module maintains a separate point-to-point bus connection with a second module. Data passing between the memory controller and the second memory module passes through a buffer circuit on the first memory module. For data received from the memory controller, the buffer circuit also passes that data up a module bus segment to a first bank of memory devices. That bank of memory devices maintains a second module bus segment with a second bank of memory devices. Data passing between the buffer circuit and the second bank of memory devices passes through a pass-through circuit on the first bank of memory devices. In this manner, a point-to-point memory bus architecture can be maintained even when a memory module contains more than one bank of memory devices.

This present invention relates generally to digital memory devices and systems, and more particularly to bus architectures and bus communication methods for such devices and systems.
Microprocessors, digital signal processors, digital imaging devices, and many other types of digital data processing devices rely on an attached high-speed memory system to hold data and/or processor instructions needed by the processing device. As these processing devices become faster and more powerful, the increased demands placed on them generally translates to a need for larger and faster attached memory systems.
FIG. 1 depicts a typical memory system configuration. One or more memory devices 26AA, 26AB, 26BA, 26BB, 26CA, 26CB interface with a memory controller 20 through a memory bus 22. A host (e.g., a central processing unit (CPU), not shown) also connects to memory controller 20 through a front-side bus FSB. The memory devices hold data in arrays of addressable memory cells. Memory controller 20 controls the exchange of data between the host and the memory storage devices.
Memory bus 22 carries memory signals on a set of signal lines. Memory signals fall generally into one of several categories including clock and control signals, address signals, command signals, and data signals. Data signals carry the actual data that will be stored in, or retrieved from, a memory device. Address signals specify the location within a memory device where data is to be read from or written to, and may also select which of several memory devices is to be accessed. Command signals instruct a memory device as to what type of operation is to be performed, e.g., read, write, refresh, and possibly as to which of several access modes (such as a burst mode) should be used for a data transfer. Clock and control signals synchronize the other signals passing between controller 20 and the memory devices. Although memory bus 22 may use a separate signal line for each memory signal (e.g., 32 address lines to transfer a 32-bit-wide address in one clock cycle and 32 data lines to transfer a 32-bit-wide data word in one clock cycle), various schemes also exist to re-use one or more signal lines for different memory signals during different clock cycles of a memory transaction.
In the configuration shown in FIG. 1, memory bus 22 is a multi-drop memory bus. In other words, bus 22 is arranged with a backbone of signal lines. A signal line stub, or xe2x80x9cdropxe2x80x9d, connects each of the memory devices to the backbone. Typically, memory bus 22 will comprise a collection of leads routed on a printed circuit board 21 known as the xe2x80x9cmain boardxe2x80x9d or xe2x80x9cmotherboardxe2x80x9d. Memory controller 20 mounts to motherboard 21 and connects to one end of the leads comprising memory bus 22. Each drop of memory bus 22 connects to an electrical terminator, or socket. A typical main board contains multiple memory sockets, e.g., the three sockets 28A, 28B, and 28C shown in FIG. 1.
Memory is added to the memory system by inserting memory modules (e.g., 24A, 24B, 24C) into one or more of the sockets. One popular type of memory module is a Dual In-line Memory Module, or DIMM. The DIMM is a rectangular low-profile circuit board that has electrical contact points arranged on both sides along one long edge. The contact points form electrical connections to the main board""s memory bus when the DIMM is inserted into a DIMM memory socket.
A DIMM generally has multiple individual memory devices mounted to it. The devices all work in parallel to perform memory functions. For instance, a DIMM may have eight memory devices, each of which receives the same memory address from the controller. If the size of a data word is 32 bits, each of the memory devices is responsible for four bits of the data word that is placed on the memory bus. The DIMMs depicted in FIG. 1 are dual-bank DIMMs, i.e., an xe2x80x9cAxe2x80x9d bank and a xe2x80x9cBxe2x80x9d bank of memory devices reside on the DIMM. The A bank and the B bank occupy logically separate areas of memory space, such that each bank can be addressed separately.

Multi-tier point-to-point buffered memory interface


A front and rear wheel steering system for a vehicle has a front steer system (23, 25) and a rear steer system (21, 22) with a rear steer controller (12) functioning to set the rear steer angle in dependence upon front steer angle and vehicle speed. A low load capacity feedback device (14) functions to maintain a predetermined relationship between front and rear wheel steer angles with an overload protector (74, 77, 78) protecting the feedback device (14) from damage due to the application of loads above a predetermined level.

1. Field of Invention
The present invention relates to four wheel steering systems for vehicles and more particularly front and rear wheel steering controlled by steering input from a driver operating a steering wheel. Typically, such systems provide that the rear wheels turn in the same direction as the front wheels in modes of operation associated with high vehicle speeds and in opposite directions in modes of operation associated with low vehicle speeds and intermediate degrees of turn of the rear wheels at speeds intermediate between such high and low speeds.
2. Description of Prior Art
The prior art in this area includes U.S. Patent specifications No. 3,596,730 (Cecce); 4,313,514 (Honda); 4,467,885 (Honda); 4,483,547 (Honda); 4,660,844 (Honda); 4,572,316 (Mazda); 4,646,867 (Mazda); 4,730,839 (Mazda); 4,733,878 (Mazda); 4,781,261 (Toyota); 4,770,264 (Lotus). As exemplified by these patents, innovation in the area of four wheel steering has been extremely diverse in terms of the technical solution to the problem. Surprisingly, as yet, this has not resulted in widespread adoption of such steering systems in the market-place notwithstanding that test reports indicated that vehicles incorporating four wheel steering provide several advantages including improved safety in high speed driving Two presently marketed systems are broadly covered by Honda U.S. Pat. Nos. 4,313,514 and 4,467,885 and Mazda U.S. Pat. Nos. 4,572,316 and 4,730,839 and have been described extensively in the technical literature. Information concerning the current commercial system adopted by Mazda in their MX-6 vehicle can be found in Car Australia magazine of February 1989 at page 52 et seq and a Technical Information document published by Mazda Australia Pty Limited entitled: "The Mazda Speed Sensing Computerised 4-Wheel Steering System". The present invention will be described primarily with respect to these two examples of the prior art. In the Honda system, the rear steering is entirely mechanically driven and not directly speed dependent, whereas the Mazda system is speed dependent and therefore more relevant to the present invention.
The reluctance in the market broadly adopting four wheel steering systems may reside in that they are costly, add considerable weight to the vehicle, and have serious functional shortcomings. Also, it may be that those systems enforce compromises in the design of associated front and rear suspensions which result in less desirable suspension performance. In many cases their performance depends upon electronic signals between front and rear steering gears which, in the event of a malfunction, may cause serious vehicle control problems for the driver. Where the front and rear steering gears are mechanically linked by a rotating shaft, as is the cases of Honda and Mazda, less reliance is placed on electronic signal transmission, but there is a marked deficiency in road "feel" to the driver due to high levels of friction of the respective rotating shaft arrangements.
In the Honda Prelude arrangement, a relatively conventional rack and pinion power steering gear is provided in the front steering gear having an additional rack which drives a pinion and rotatable shaft extending to the rear of the vehicle where another full mechanical steering gear is located. The rear steering gear incorporates a function generating mechanism which provides the reversing of the direction of rear steer as a function of steering wheel angle. Since each element of the mechanical linkage imposes additional friction, the overall system is characterised by having poor steering "feel" and poor self-centering action. The front to rear steering shaft requires seals, journals and universal joints at each end which not only add to the friction but, due to the great length of such a shaft, also results in a degree of compliance. To minimize the resulting loss of steering response the components are very robust and accurately fitted, and are therefore heavy and expensive.
In the Mazda MX-6 arrangement magnitude and direction of the rear-steer is made to be a function of not only front steering wheel angle but also vehicle speed. The rear steering gear incorporates a nutating axis or bobbing axis device inclinable either side of a nul position, providing the same-direction rear-steer at high speeds, opposite direction rear-steer at low speeds, and no rear-steer at a nul position corresponding to a "cross-over" speed. The axis inclination is varied according to vehicle speed by a stepper motor. By this means a single mechanism provides two separate functions of the rear steering gear, one speed dependent and one front-steer angle dependent. The rear steering gear also incorporates a hydraulic servo-system to provide power actuation to the rear wheels. In this case at least four separate power and/or signal connections are required between the front and rear steering gears.
A rotatable shaft extending between front and rear steering gears is driven by an additional rack and pinion arrangement incorporated in the front steering gear. This arrangement provides the front-steer angle input to the rear steering gear and serves as a fail-safe back-up in the event of hydraulic or electrical failure, at least up to moderate steering loads which apply during medium to high speed driving. Steering loads in parking can be several times as great, and in order to protect the nutating device from damage in a power-off situation, the excess loads are relieved by a spring loaded device which suffices to steer the car once it is in motion. In this Mazda arrangement an overload protection device is positioned on the output or highload side or the rear steer power cylinder in the form of a relatively heavy spring which also functions as a centering device in case of failure of electronic or hydraulic systems. In its function as an overload protector it acts to prevent damaging load being transmitted to the "phase control unit" in the case where high steering resistance loads are applied to the rear steer wheels such as when a rear wheel is parked too close to a curb while the front free to turn.
Also, providing the additional rack in the front steering gear increases the rack length and hence the pivot length between tie rod attachments, enforcing the use of shorter tie rods than optimal, and hence stiffer suspension spring rates.
The required level of robustness of the mechanical linkage, again therefore in this case, introduces friction to the overall steering system, and is difficult to accommodate safely under the relatively flat floor pan of modern front wheel drive vehicle.


There is provided a defect inspection apparatus including: an electron scanning unit configured to scan a surface of a sample with an electron beam; a plurality of detectors arranged around an optical axis of the electron beam and configured to detect electrons emitted from the surface of the sample by scanning the electron beam; a signal processing unit configured to generate image data of the surface of the sample based on detection signals from the detectors; an analysis unit configured to detect a defect due to irregularities of the surface of the sample based on the image data; and a control unit configured to control a scanning speed of the electron beam depending on the type of the sample.

With the progress of microfabrication of semiconductor devices, an EUV exposure technology using extreme ultraviolet (EUV) light, which has a short wavelength, has been developed. An EUV mask used for the EUV exposure is a light reflective mask, and has a pattern formed of a reflective portion, which reflects light, and an absorption portion, which absorbs light.
If there is a defect arising from irregularities of about several nanometers on a surface of the reflective portion of the EUV mask, the phase of the extreme ultraviolet light at the position is displaced, which may change dimensions or shape of a pattern transferred onto a semiconductor wafer.
Such minute irregularities are difficult to detect by observation using a normal scanning electron microscope (SEM) because the irregularities are buried in noise. For this reason, an atomic force microscope (AFM) is used for inspection of the EUV mask.
Japanese Laid-open Patent Publication No. 2012-112927 shows an example of such defect inspection apparatus and method.

Defect inspection apparatus and method using a plurality of detectors to generate a subtracted image that may be used to form a subtraction profile


Microorganisms and processes for the fermentative preparation of L-cysteine, L-cystine, N-acetylserine or thiazolidine derivatives. The microorganism strain which is suitable for the fermentative preparation of L-cysteine, L-cystine, N-acetylserine and/or thiazolidine derivatives, overexpresses at least one gene which encodes a protein which is directly suitable for secreting antibiotics, or other substances which are toxic for the microorganism, out of the cell.

1. Field of the Invention
The invention relates to microorganisms and processes for the fermentative preparation of L-cysteine, L-cystine, N-acetylserine or thiazolidine derivatives.
2. The Prior Art
It is well known to prepare many amino acids by fermentation. However, there has previously not been any economical process for the fermentative preparation of L-cysteine.
Thiazolidine derivatives and the corresponding hemithioketals are generally produced when cysteine is condensed with ketones or aldehydes. The chemical condensation of cysteine with different ketones or aldehydes, in particular with .alpha.-ketoacids, is known. The condensation takes place with the hemithioketal as the intermediate. The hemithioketal is produced by the nucleophilic attack of the free electron pair of the sulfur on the electron-deficient carbon atom of the aldehyde group or keto group. Ring closure with the elimination of water then leads to the corresponding thiazolidine derivative.
The formation of thiazolidine derivatives is shown in a general manner in the following reaction sequence. ##STR1##
In this reaction, R.sub.1 and R.sub.2 can denote any organic radicals.
The starting compounds are consequently in equilibrium with the thiazolidine derivative through the intermediate hemithioketal. For this reason, the hemithioketal is generally also present in aqueous solution in addition to the thiazolidine derivative.
According to the present invention, "thiazolidine derivative" is also understood as meaning an equilibrium of these substances with the corresponding intermediate hemithioketal.
It has not previously been reported that thiazolidines are direct metabolites of cells. All reports of the formation of thiazolidines by cells are based on the external addition, in an excess, of one of the starting compounds, usually L-cysteine. This cysteine is then converted into pyruvate by desulfhydration and deamination. The pyruvate is then reacted with the added cysteine. (Ronald C. Simpson et al., Biochimica et Biophysic Acta, 496 (1977), 12-19). Kredich et al. have reported, in J. of Biol. Chem. 248, 17: 6187-6196, that 2-methyl-2,4-thiazolidinedicarboxylic acid is formed in vitro when L-cysteine is subjected to an enzymic desulfhydration. These authors consider that it is extremely unlikely that this substance is formed in vivo.
It is known to use thiazolidines as racemic precursors for preparing L-cysteine by means of biotransformation (EP-A 0 101 052, Ok Hee Ryu et al., Biotechnology Letters 17 No. 3, 275-280 (March 1995)). When the racemate is employed for preparing L-cysteine, it has to be converted stereoselectively into L-cysteine using enzymes or whole cells. The remaining diastereomers have to then be racemized once again. For these reasons, this biotransformation has a high cost.
The chemical synthesis of thiazolidines from racemic cysteine and a corresponding ketone or aldehyde leads to four different diastereomers. Carrying out a chemical synthesis from enantiomerically pure L-cysteine is expensive. There are difficulties in subsequently isolating the L-cysteine. For this reason, a process for preparing thiazolidine diastereomers which possess the R configuration at the C4 atom suffers from the high costs of the starting compounds.

Consortium fur Elektrochemische Industrie GmbH


An image forming includes a main body, an exposing unit, a process cartridge, and a positioning unit. The exposing unit is fixed to the main body and includes an exposing member. The process cartridge is attachable to an attaching portion provided on at least one of the main body and the exposing unit, and includes a photosensitive drum. The positioning unit positions the process cartridge with respect to the exposing unit so that the photosensitive drum faces the exposing member in a first direction when the process cartridge is attached to the attaching portion, allowing the photosensitive drum to be exposed by the exposing member.

In general, an image forming device is configured to: irradiate an electrically charged photosensitive drum with a light to change the potential of the irradiated portion on the photosensitive drum to thereby form an electrostatic latent image on the photosensitive drum; supply the electrostatic latent image with a developer to form a developer image; and transfer the developer image onto a recording sheet, whereby a predetermined image is formed on the recording sheet.
As such an image forming device, there is known one having an LED head for emitting a light which is swingably supported by the device body through an arm and a process cartridge provided with a photosensitive drum which is detachably attached to the device body (Refer to Japanese Patent Application Publication No. 5-249767). In this image forming device, when a cover is closed after attachment of the process cartridge, the arm is swung by a mechanism that is activated by being brought into contact with a part of the cover, causing the LED head to come close to a photosensitive drum provided in the process cartridge for positioning. That is, after the position of the process cartridge with respect to the device body has been set, the position of the LED head with respect to the process cartridge is determined. Note that the positioning of the LED head and process cartridge is achieved by an engagement between a positioning hole formed on the LED head side and a projection formed on the process cartridge side.
However, according to a conventional technique, the position of the LED head is determined with respect to the process cartridge, so that the positioning accuracy of the LED head with respect to the device body may deteriorate due to influence of a positioning error between the device body and process cartridge and positioning error between the process cartridge and LED head. When the positioning accuracy of the LED head with respect to the device body deteriorates as described above, the positioning accuracy between a recording sheet which is fed while being positioned with respect to the device body and LED head correspondingly deteriorates, the printing position may shift.


A user equipment terminal (UE) operates in a wireless network according to a configuration. The UE receives the configuration for a physical downlink control channel (PDCCH), and detects downlink control information (DCI) in the PDCCH. From the DCI, the UE receives control information for a serving cell configured with one or more bandwidth units in a frequency domain. The control information is provided for each bandwidth unit of the serving cell. According to the control information, the UE performs a downlink reception from the serving cell or an uplink transmission to the serving cell.

The Fifth Generation New Radio (5G NR) is a telecommunication standard for mobile broadband communications. 5G NR is promulgated by the 3rd Generation Partnership Project (3GPP) to significantly improve on performance metrics such as latency, reliability, throughput, etc. 5G NR supports operations in unlicensed spectrum (NR-U) to provide bandwidth to mobile users in addition to the mmWave spectrum. Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard.
The 3GPP defined a coexistence mechanism for different radio air interfaces to share the unlicensed spectrum. For example, the unlicensed spectrum may be shared by a Wi-Fi network and a 5G NR network. To determine whether a channel is clear for transmission, a transmitting station performs a Clear Channel Assessment (CCA), such as a listen-before-talk (LBT) process, before signal transmission. In the LBT process, the transmitting station listens to (e.g., senses) a subband before transmission in that subband to determine whether the subband is idle or occupied by ongoing transmission activities. An LBT failure indicates that the subband is occupied. A transmitting station can start transmission in a subband when LBT succeeds for that subband, or waits until LBT succeeds for that subband.
The existing 5G NR technology can be further improved to benefit operators and users of the unlicensed spectrum. These improvements may also apply to other multi-access technologies and the telecommunication standards that employ these technologies.

Control information for wideband operation


An integrated circuit capacitor includes a substrate, a first metal electrode on the substrate, and a dielectric layer on the first metal electrode. The dielectric layer includes a homogeneous combination of at least two dielectric materials having permittivities varying in an opposite way based upon an electric field, with a proportion of each dielectric material being chosen so that the integrated circuit capacitor has a desired voltage linearity. A second metal electrode is on the dielectric layer.

The present invention relates to integrated circuits, and, more particularly, to an integrated capacitor on a silicon substrate.
It is common practice to design integrate circuits with one or more high value integrated capacitors, which advantageously replace conventional discrete capacitors. Integrated capacitors have various applications in the field of analog and RF circuits. These applications include filtering supply voltages in resonant antenna circuits, for example.
Among the known integrated capacitors, capacitors with metal electrodes have several advantages when compared to capacitors with polysilicon electrodes. Metal electrodes have an excellent electrical conductivity, whereas polysilicon electrodes need a silicide formation process in the presence of a metal like tungsten or titanium to have the same effect.
Capacitors with metal electrodes are very easy to manufacture. The lower electrode is generally made from one of the last metal layers of the integrated circuit, such as the metal layer used to make conductive tracks, for example. Compared to conventional methods of manufacturing integrated circuits, the design of a capacitor with metal electrodes only needs a step of depositing a dielectric layer on a pre-existing metal layer that is used as a first electrode layer, and a step of depositing a second electrode metal layer thereon. The dielectric layer is deposited at a moderate temperature of about 400xc2x0 C. so that the metal layer of the first electrode is not damaged. Capacitors with metal electrodes have a small parasitic capacitance with respect to the silicon substrate because they are made, as just described, on one of the last levels of the integrated circuit.
However, capacitors with metal electrodes present a poor voltage linearity. The voltage linearity is defined by the ratio xcex94C/C, where C is the value of the capacity at a voltage equal to zero and xcex94C is the variation of the capacity C according to the applied voltage. The ratio xcex94C/C of a capacitor with metal electrodes is typically on the order of 200 10xe2x88x926/V, i.e., a linearity defect that is at least 10 times above the value which is generally tolerated by designers of analog integrated circuits.
For this reason, capacitors with metal electrodes have at present only a few applications in the field of analog and RF circuits in spite of the advantages as discussed above. After various studies, the inventors of the present invention have hypothesized that the non-linearity phenomenon, which appears only in capacitors with polysilicon electrodes, is linked to the fact that the dielectric is deposited at a moderate temperature. This results in the incorporation of many impurity atoms (H, N, C . . . ) and the creation of many interface states, generally taking the form of pending linkages.
Furthermore, capacitors with metal electrodes, unlike capacitors with polysilicon electrodes, are not subject to a high temperature anneal. A high temperature anneal is conventionally performed with a temperature on the order of 850xc2x0 C. during several tens of minutes. In the manufacturing process of integrated circuits, conventional annealing steps for dopant activation are always performed before depositing the metal layers to avoid damaging them.
Thus, it appears that the poor voltage linearity of capacitors with metal electrodes is linked to the presence of impurities in the dielectric and/or to an incomplete formation of the dielectric that a high temperature annealing causes to partly disappears. This is confirmed by equations (1) to (3), which respectively provides the value of an electric capacity C as a function of the absolute permittivity ∈ of the dielectric, and the value of the permittivity ∈ of the dielectric as a function of the voltage V or the electric field E applied to the capacitor. The three equations are as follows:
C=∈*S/dxe2x80x83xe2x80x83(1)
∈=∈0+A+B*E2xe2x80x83xe2x80x83(2)
∈=∈0+A+B*V2/d2xe2x80x83xe2x80x83(3)
The variable S is the surface of the electrodes of the capacitor, d is the distance between the electrodes or a thickness of the dielectric, ∈0 is the permittivity of the vacuum, A is a constant and B is a quadratic term multiplied by the square of the applied voltage.
It is clear that the variations of a capacity according to voltage are due to variations of the permittivity ∈ of its dielectric, and, more particularly, to the existence of the quadratic term B. The quadratic term B is generally very small compared to the constant A.
However, the thickness d of the dielectric of an integrated capacitor is very small, e.g., on the order of some tens of nanometers, and supports a voltage of a few volts. In these conditions, the electric field E, equal to V/d, is very high and the effect of the quadratic term is no longer negligible. For example, a capacitor having a dielectric with a thickness of 30 nm subject to a voltage of 3V supports a very high electric field of 108V/m.
In view of the foregoing background, it is an object of the present invention to provide an integrated capacitor presenting a satisfactory voltage linearity without necessarily requiring a high temperature anneal, as well as a method of manufacturing the capacitor.
Another object of the present invention is to provide a low temperature dielectric having a quadratic term as small as possible, and a manufacturing method of such a dielectric.
These and other objects, features and advantages are provided by a dielectric comprising a homogeneous combination of molecules of at least two dielectrics having permittivities varying in an opposite way according to the electric field. The proportion of each dielectric in the combination is chosen so that the combination presents a permittivity that is less sensitive to the electric field.
According to one embodiment, the dielectric comprises SiOxNy, with x being different from y.
The present invention also relates to a capacitor integrated on a silicon substrate. The capacitor preferably comprises layers of first and second electrodes, and a dielectric layer therebetween.
The dielectric layer comprises a homogeneous combination of molecules of at least two dielectrics having permittivities varying in an opposite way according to the electric field. The proportion of each dielectric in the combination is chosen so that the capacitor presents a satisfactory voltage linearity.
According to one embodiment, the dielectric is of the SiOxNy type, with x being different from y. The material forming the layers of first and second electrodes is preferably chosen from the group comprising aluminium, copper, tungsten, titanium, titanium nitride and their alloys.
The invention also relates to a method of manufacturing a capacitor integrated on a silicon substrate. The method comprises depositing a first electrode layer, depositing a dielectric layer, and depositing a second electrode layer. Depositing the dielectric layer comprises depositing a homogeneous combination of molecules of at least two dielectrics having permittivities varying in an opposite way according to the electric field. The proportion of each dielectric in the combination is chosen so that the capacitor presents a satisfactory voltage linearity.
According to one embodiment, the two combined dielectrics are silicon oxide and silicon nitride. The dielectric comprises a composition of SiOxNy, with x being different from y. The proportion of each dielectric in the combination is determined by preliminary experiments by observing the voltage linearity of test capacitors comprising various dielectric proportions.
The dielectric is preferably deposited under vapor phase, and the proportion of each dielectric in the combination is in particular determined by an adjustment of the gaseous rates of the gases forming each of the dielectrics of the combination. The layers of the first and second electrodes are preferably made of a material chosen from the group comprising aluminium, copper, tungsten, titanium, titanium nitride and their alloys.

Integrated capacitor with a mixed dielectric


A strip deflection roller, especially a tension measuring roller or looper roller for matching tension in rolling stock between two roll stands for hot rolling and cold rolling of strip. The strip deflection roller includes at least five adjacent disks which are mounted on a common eccentric shaft so as to be freely rotatable independently. At most two of the disks are mounted concentric to the axis of rotation of the eccentric shaft, and the height positions of the rest of the disks can be changed for influencing the profile and regulating the flatness of the strip guided over the strip deflection roller by rotating the eccentric shaft.

The invention is directed to a strip deflection roller, especially a tension measuring roller or looper roller for matching tension in rolling stock between two roll stands for hot rolling and cold rolling of strip.
Tension measuring rollers or looper rollers are used in hot rolling mills and cold rolling mills, for example, between two four-high stands and normally serve for tension matching between stands. In cold rolling, the tension measuring roller is moved to a fixed position and, by means of the force transmitted to the tension measuring roller by the strip tension via the strip, tension matching is achieved by means of suitable measurement sensors by adapting the rolling speed of the stands. In hot rolling, looper rollers are used to form loops in the strip for tension matching, wherein the looper position, i.e., its height position, is a measure for the looped strip reserve between the stands. In matching the speeds of the stands, it is attempted to keep the strip reserve, and therefore the looper position, within a determined area.
It is impossible to correct the strip tension along the strip width in the tension measuring rollers and cylindrical looper rollers used in the prior art. Since regulation of profile and flatness is indispensable in modern rolling mills of the type described above, it is the object of the present invention to use the tension measuring rollers or looper rollers for matching tension in rolling stock between two roll stands also as means for regulating profile and flatness. This requires a special construction of the strip deflection rollers.
To meet this object, it is suggested according to the invention that the strip deflection roller comprises at least five adjacent disks which are mounted on a common eccentric shaft so as to be freely rotatable independently from one another, at most two of these disks being mounted concentric to the axis of rotation of the shaft, and the height positions of the rest of the disks can be changed for influencing the profile and regulating the flatness of the strip guided over the strip deflection roller by means of rotating the eccentric shaft.
The diameters of the disks can be identical or may vary. With appropriate selection of the disk diameter and eccentricity of the eccentric shaft, the outer contour of the strip deflection roller can be adjusted by rotation of the stepper motor continuously from a concave profile to a parallel profile to a convex profile, so that the flatness and, if required, the profile of the strip guided over the roller can be corrected.
It is advantageously provided that the eccentric shaft can be driven in rotation continuously by a stepper motor acting on the axle of the shaft.
According to the invention, for use in roll stands for cold rolling of strip, the strip deflection roller is moved to a fixed position relative to the strip which is deflected under tension and the desired flatness correction is adjusted by rotating the eccentric shaft axle. In this regard, the flatness correction is limited by the geometry of the strip deflection roller and the adjusted tension.
When the invention is applied in roll stands for the hot rolling of strip, the strip deflection roller is used as a looper roller, as it is called, and its height position is adjusted to compensate for speed differences in the two stands, the desired flatness correction likewise being adjusted by rotating the eccentric shaft axle.
Accordingly, in contrast to cold rolling mills, the strip deflection roller is not moved to a fixed position in the hot rolling mill, but, rather, by forming a strip reserve between two stands, serves as a looper for compensating for speed differences between the stands. As a result, there are variations in the height of the looper and differences in the relative elongation or strain depending on the looper height. These differences can be corrected by changing the strip deflection roller profile in continuous manner in that the stepper motor adjusts the appropriate strip deflection roller position by rotating the eccentric shaft.
In an advantageous construction of the invention, it is suggested that the strip deflection roller is used simultaneously as a tension measuring roller by outfitting it with suitable known measurement transmitters.
The invention is described in the following by means of an embodiment.

Strip deflection roller, especially a tension measuring roller or looper roller


To increase bandwidth, a channel, which normally is limited to contention-free transmissions, is used for other purposes during times when it is not needed for contention-free transmissions. Although the channel is located in a contention-free portion of a beacon cycle, supplemental uses of this channel include the contention-based transmission of data that normally would be sent during a contention portion of the cycle. These transmissions include those made under the CSMA protocol.

Network design options include contention-free networks and contention-based networks. In a typical contention-free network, one of the devices on the network manages time slot use. In response to requests from other devices wanting to send a data stream, available time slots are allocated by a time slot manager. Once assigned, a transmitter can generally continue to use a time slot, uninterrupted by other streams, until the transmission ends. The original data stream packet intervals that are transmitted over the network are reconstructed by a receiver on the network. An advantage of contention-free communication is that quality of service (QoS) is very high.
However, contention-free networks also have some disadvantages. For example, if the time slot manager is disconnected, another device must take over the time slot management, thus requiring that other devices on the network also be configured with time slot management capability which, in turn, increases network device cost. Furthermore, in response to device connection or disconnection, a full bus reset occurs that disturbs bus communications. Contention-free control operates satisfactorily on a dedicated, noise-free network such as IEEE 1394, but it often is not well suited for use on networks subject to harsh transmission conditions such as an 802.11 wireless network or a power-line communications (PLC) network.
In a typical contention-based network (such as, for example, an Ethernet network), traffic is often controlled using the Carrier Sense Multiple Access (CSMA) protocol. Under CSMA, when one device on the network wants to communicate with another device, the transmitter first detects whether there is a carrier on the bus. If no carrier is detected, then the device commences communication. If however a carrier is detected, then the transmitter enters a back-off mode, and after a delay, attempts the process once again. The wait time during back-off is generally randomized so that two waiting devices do not collide again. Under a conventional CSMA protocol, the bus is not controlled by a time slot manager.
Contention-based networks have both advantages and disadvantages. One advantage is that users are allowed to freely connect or disconnect devices on or from the network without the penalty of a bus reset. Each device need not be concerned with the network status, i.e., what devices are or are not connected to the network. The network interface is simple and low-cost, because no time slot management capability is required. A disadvantage is that QoS is not guaranteed, and therefore when the network is busy, devices are subject to indeterminate wait intervals.
Currently, advances in network design have resulted in an expanded use of home networks. Popular standards include the 802.11 wireless standard and the "HomePlug™ 1.0" power line communications (PLC) network standard. Both of these standards are Ethernet-equivalent and do not provide QoS for audio-visual (AV) data streaming or other uses. Although other network standards such as IEEE 1394 provide QoS, they are not well suited to a number of applications due to a limited cable transmission range, and because cables must be routed from device to device, such as between rooms in a household.
While the existing PLC standard does not have QoS, a next generation PLC standard, "HomePlug™ AV," is expected to have this. Under this standard, beacon cycles are divided into a contention period (CP) that employs a CSMA or similar protocol and a contention-free period (CFP). Contention-based communications will use the CP which is on first-come, first-served basis. No time allocation is reserved within this portion of the beacon cycle. The CFP is used for contention-free data transmission, especially AV streaming and voice over Internet protocol (VoIP) streaming. Once a time allocation is reserved within the CFP portion of the beacon cycle, the transmitter uses that allocation period, or "channel," every beacon cycle until all of the data is sent and the transmission terminates. No other traffic is permitted to disturb the transmission.
PLC networks operate under harsh conditions. Signal attenuation is high—especially for a long distance transmission. Also, there are many noise sources, such as for example, hair dryers, lamp dimmers, switching regulator power supplies, etc. Thus packet errors do occur occasionally in these conditions. To solve these errors, a transmitter in a PLC network needs quality of service (QoS) transmission capabilities, i.e., to retransmit the erroneous or missed packets. Usually, a contention-free transmission (such as, for example, the transmission of AV data) reserves only a required minimum bandwidth in the CFP. There is no bandwidth reserved for retransmission of missing packets.
Reserving a bandwidth or channel for QoS transmissions would provide a useful feature for the transmission of AV data or other data over a PLC network. However reserving a channel for QoS transmissions represents an inefficiency in the use of overall CFP bandwidth, because such a channel would not be used for significant amounts of time. Thus there is a need to improve the use of bandwidth while at the same time allowing bandwidth for error recovery or other priority uses.

Hybrid access to a contention-free period channel


Embodiments of the invention include an IC that includes a core used for ordinary operation and a thin power circuit. The thin power circuit can be configured to use very little power. The IC can also include a digital interface and a connection thereto. The IC can initiate transition to low power mode during which the core and various I/O pads can be shut down. However, the thin power circuit can be kept powered up. The thin power circuit can monitor the digital interface for a predefined wake up signal. When the wake up signal is detected, the thin power circuit can power up the core and any powered down I/O pads. The thin power circuit can also include a dedicated power on reset (POR) cell. This POR cell can be distinct than other POR cells used for the IC and can be specifically designed to for efficient operation.

Power consumption is a very important issue for modern integrated circuits (ICs). Low power consumption is often a desired attribute of all types of electronic devices. However, power conservation can be especially important for portable devices that rely on battery power.
To improve power conservation, many integrated circuits can feature a low power mode (also referred to as a sleep mode). The low power mode can be such that an IC in this mode will consume minimal power while also having reduced functionality. The low power node can be utilized when the IC is not needed. For example, the microprocessor of a notebook computer may go into low power mode when a user closes the notebook without turning it off.
Most digital ICs can include one or more digital interfaces used for communications with the outside world. Operating the digital interfaces usually requires a significant amount of logic and power from the IC. For example, the digital interfaces can be synchronous, and operating them can require generating a clock signal. Therefore, many existing ICs can power down their digital interfaces during sleep mode. However, that means that these ICs cannot receive a signal to power up from the outside world through the digital interface. Thus, many existing ICs include dedicated analog interfaces for the purpose of receiving power-up and power-down signals. Analog signals can be easier to process, and processing them need not require much power.
However, the additional analog interfaces can add significant cost to an IC and the device it is connected to. For example, the analog interface can require additional pins for the IC, additional wires on a printed circuit board (PCB) on which the IC is positioned, additional pins on a second IC that controls the first IC's functionality, etc. These requirements may add up to a noticeable cost increase.
Another existing approach is not to place any low power circuitry into the IC, but to simply remove power coming into the IC. However, this approach can require another external circuit to disconnect power from the IC. Again, this can significantly increase the cost of a device because of additional components required and additional space requirements on the PCB.