A device and method of optical fiber condition monitoring in optical networks is described. The front end of each branch of the optical network is installed with an optical filter that can filter an optical signal with a different wavelength. Optical signals of different wavelengths enter each of the branches in sequence for analysis, so that the condition of each branch on the optical network can be determined. This solves the problem of interference among the branches when monitoring the optical fiber condition on an optical network.

1. Field of Invention
The invention relates to an optical network and, in particular, to a device and method that can determine the conditions of individual optical branches in optical networks.
2. Related Art
Currently, the passive optical network (PON) undoubtedly is the hottest technique for the optical access network. However, the optical fiber monitoring technology is still limited. The current solution of using an optical time-domain reflectometry (OTDR) results in the problem that individual branches are hard to distinguish. In particular, the discrimination of branches of similar lengths is restricted by the OTDR dead zone. This is because that the light pulse for detection can enter each branch of the optical fiber. Likewise, the optical waves reflected from each optical path are received by the OTDR. Therefore, the reflected light in different branches but with the same distance from the OTDR will contribute to the optical receiver of OTDR, thus accumulating on the OTDR trace. In this case, when one optical path has an event occurring, especially when two paths are close in length, then the conventional monitoring technology cannot determine in which branch the event is occurring.
As shown in FIG. 1, a 1:2 splitter 10 is used at a distance of 3.07 km from the front end in an optical network structure with multiple branches, similar to the passive optical network. A 1:8 splitter 20 is further used at a distance of 2.08 km from the previous splitter. The output terminals a through d are coupled to the splitters at 0.42 km, 1.54 km, 1.67 km, and 2.45 km. The output terminals e to h are not connected. The front end of the network employs a conventional OTDR to measure the optical fiber condition of the network, as shown in FIG. 2, showing the path diagram of the OTDR output. Path 2 shows the attenuation of the 1:2 splitter 10. Path 4 shows the attenuation of the 1:8 splitter 20. The output terminal a to the tail of d also show the paths 5, 6, 7, and 8 in the OTDR trace. All the branch conditions are accumulated onto the same path diagram. Although the conditions on the optical network can be displayed, if one of the branches has a problem it can be discovered by comparing with the original trace with no problem conventionally. This is because at the problem point, the trace after the position is changed. The change stops at the end of the branch with a problem. This is the conventional optical fiber condition monitoring method, as disclosed in U.S. Pat. No. 5,187,362.
However, on these two optical paths of similar lengths, such as paths 6 and 7, it is difficult to distinguish them due to the limitation of the OTDR dead zone. If the length of the optical path increases, an OTDR signal with a longer pulse has to be used to detect. In this case, the dead zone also increases so that one is unable to distinguish the 1.54 km and 1.67 km paths. When an even happens in one of them, it is impossible for find what in which path it is using the conventional monitoring method. In addition, the reflected light from all paths overlap and present on the same OTDR trace if the conventional monitoring method is used. Therefore, one cannot detect the optical fiber properties (e.g., transmission attenuation) of individual paths. It is thus imperative to develop a new monitoring technique to solve the discrimination problem.

Device and method of optical fiber condition monitoring in optical networks

Industrial Technology Research Institute


A received layout identifies a plurality of circuit components to be included in an integrated circuit (IC) layer for double patterning the layer using two photomasks, the layout including a plurality of first patterns to be included in the first photomask and at least one second pattern to be included in the second photomask. A selected one of the first patterns has first and second endpoints, to be replaced by a replacement pattern connecting the first endpoint to a third endpoint. At least one respective keep-out region is provided adjacent to each respective remaining first pattern except for the selected first pattern. Data are generated representing the replacement pattern, such that no part of the replacement pattern is formed in any of the keep-out regions. Data representing the remaining first patterns and the replacement pattern are output.

In semiconductor fabrication processes, the resolution of a photoresist pattern begins to blur at about 45 nanometer (nm) half pitch. To continue to use fabrication equipment purchased for larger technology nodes, double exposure methods have been developed.
Double exposure involves forming patterns on a single layer of a substrate using two different masks in succession. As a result, a minimum line spacing in the combined pattern can be reduced while maintaining good resolution. In a method referred to as double dipole lithography (DDL), the patterns to be formed on the layer are decomposed and formed on a first mask having only horizontal lines, and on a second mask having only vertical lines. The first and second masks are said to have 1-dimensional (1-D) patterns, which can be printed with existing lithographic tools.
Another form of double exposure is referred to as double patterning technology (DPT). Unlike the 1-D approach of DDL, DPT in some cases allows a vertex (angle) to be formed of a vertical segment and a horizontal segment on the same mask. Thus, DPT generally allows for greater reduction in overall IC layout than DDL does. DPT is a layout splitting method analogous to a two coloring problem for layout splitting in graph theory. The layout polygon and critical space are similar to the vertex and edge of the graph respectively. Two adjacent vertices connected with an edge should be assigned different colors. If only two masks are to be used, then only two "color types" are assigned. Each pattern on the layer is assigned a first or second "color"; the patterns of the first color are formed by a first mask, and the patterns of the second color are formed by a second mask. A graph is 2-colorable only if it contains no odd loop.
In terms of graph theory, when the total number of relationships between patterns that violate the minimum threshold spacing for a single mask (referred to as the separator distance) is odd, an odd loop is present, and DPT cannot be used without changing the layout.
In some cases, after a layout has proceeded through double patterning decomposition, and photomasks are produced, the designer discovers an underlying logic error in the design, which must be corrected through a design change (e.g., an engineering change order). Such a design change may require new photomasks, at added expense. Because two masks are used for a single layer, the added expense is doubled.

Method and system for replacing a pattern in a layout

Taiwan Semiconductor Manufacturing Co., Ltd.


The invention relates to an aqueous suspension of precipitated silica, characterized in that its solids content is between 10 and 40% by weight, its viscosity is lower than 4xc3x9710xe2x88x922 Pa.s at a shear rate of 50 sxe2x88x921 and the quantity of silica present in the supernatant obtained after centrifuging the said suspension at 7500 revolutions per minute for 30 minutes represents more than 50% of the weight of the silica present in the suspension. The particle size distribution of the agglomerates in suspension is such that their median diameter D50 is smaller than 5 xcexcm and the deagglomeration factor FD is greater than 3 ml.

The present invention relates to an aqueous suspension of precipitated silica.
Aqueous silica suspensions are employed in very varied fields, and especially the papermaking industry or that of concrete.
For these diverse applications it in advantageous to have suspensions which have a high solids content. However, such suspensions exhibit very high viscosities, and this results in difficulties in pumping and therefore reduces the possibilities of industrial utilization.
Moreover, these suspensions tend to settle or to gel and, as a result, they exhibit an instability which makes then difficult to transport or store. Very frequently, after transportation or after a more or less long period of storage, the formation of a gel is actually observed or the deposition of a hard layer above which there is a slurry which is fluid but low in solids. It is then often impossible to resuspend the silica or to obtain a slurry exhibiting a viscosity which is sufficiently low to make it pumpable and therefore usable industrially.
The aim of the present invention is therefore to provide aqueous silica suspensions of high solids content, exhibiting a low viscosity and a good stability in time.
Thus, more precisely, the subject of the invention is an aqueous suspension of precipitated silica, characterized in that its solids content is between 10 and 40%, its viscosity is lower than 4xc3x9710xe2x88x922 Pa.s at a shear rate of 50 sxe2x88x921 and the quantity of silica present in the supernatant obtained after centrifuging the said suspension at 7500 revolutions per minute for 30 minutes represents more than 50% of the weight of the silica present in the suspension.
The solids content of the said suspension is preferably between 15 and 35% by weight. The viscosity of the said suspension is advantageously lower than 2xc3x9710xe2x88x922 Pa.s at a shear rate of 50 sxe2x88x921.
The suspension according to the invention is very stable and its stability can be assessed by virtue of a settling test which consists in centrifuging the said suspension at 7500 rev/min for 30 minutes. The quantity of silica present in the supernatant obtained at the end of this centrifuging, measured after drying the supernatant at 160xc2x0 C. until a constant weight of material is obtained, represents more than 50%, preferably more than 60% of the weight of the silica present in the suspension.
The quantity of silica present in the supernatant obtained after centrifuging advantageously represents more than 70%, in particular more than 90% of the weight of the silica present in the suspension.
Another characteristic of the suspension according to the invention relates to the particle size of the silica particles in suspension.
In fact, concentrated silica suspensions known hitherto, besides their high viscosity, have the disadvantage of comprising large-sized agglomerates in suspension, in particular making injection into a porous medium difficult.
The particle size distribution of the suspended matter can be defined by means of the median diameter D50, which is the particle diameter such that 50% of the population of particles in suspension have a smaller diameter.
Similarly, D95 represents the particle diameter such that 95% of the population of particles in suspension have a smaller diameter.
Another characteristic quantity of the suspensions is the deagglomeration factor FD. This factor, which is proportionally higher the more the silical suspension is deagglomerated, is an indication of the fines content, that is to say the content of particles smaller than 0.1 xcexcm in size, which are not detected by a particle size analyser.
FD is measured by introducing into a particle size analyser a known volume V of suspension which is diluted so as to obtain a silica content of 4% by weight, and is equal to the ratio (10xc3x97V in ml/(optical concentration detected by the particle size analyser).
The silica agglomerates present in the suspension according to the invention are small in size.
The particle size distribution of the agglomerates in suspension is preferably such that their median diameter D50 is smaller than 5 xcexcm and the deagglomeration factor FD is greater than 3 ml.
The diameter D50 is advantageously smaller than 2 xcexcm, the factor FD being greater than 13 ml and, furthermore, the diameter D95 being smaller than 20 xcexcm.
The suspension according to the invention preferably includes a filter cake originating from a precipitation reaction (referred to in what follows as xe2x80x9cprecipitation cakexe2x80x9d), which is washed, if need be, and then crumbled.
According to an embodiment of the invention the crumbling is carried out, inter alia, by a chemical route, with the result that the suspension includes aluminium in a quantity such that the Al/SiO2 weight ratio is between 1000 and 3300 ppm.
The said suspension can be prepared by various processes which are described below and which are also subjects of the present invention.
The synthesis of the silica is performed by a precipitation reaction (A) making use of an alkali metal silicate SiO2/nM2O, n being the molar ratio of the silicate, and an acidifying agent. Next, in a stage (B), the precipitation cake in separated from the reaction mixture and then, in a stage (C), is converted into a suspension which has the desired properties.
Any common form of silicates can be employed as silicate for the precipitation reaction, such as meta-silicates, disilicates and advantageously a silicate of an alkali metal M in which M is sodium or potassium.
In the case where sodium silicate is employed, the latter advantageously has an SiO2/Na2O molar ratio of between 2 and 4, more particularly between 3.0 and 3.7.
The choice of the acidifying agent and of the silicate is made in a way which is well-known per se. It may be recalled that the acidifying agent generally employed is a strong mineral acid such as sulphuric acid, phosphoric acid, nitric acid or hydrochloric acid, or an organic acid such as acetic acid, formic acid or carbonic acid.
In general it is preferred to employ sulphuric acid as acidifying agent and sodium silicate as silicate.
In a first embodiment of the invention the precipitation (A) in carried out in the following manner:
(i) an initial base stock is formed, comprising absorsportion of the total quantity of the alkali metal (M) silicate introduced into the reaction, the silicate concentration expressed as SiO2 in the said base stock being lower 20 g/l,
(ii) the acidifying agent is added to the said initial base stock until at least 5% of the quantity of M2O present in the said initial base stock is neutralized,
(iii) acidifying agent is added to the reaction mixture simultaneously with the remaining quantity of alkali metal silicate such that the ratio (quantity of silica added)/(quantity of silica present in the initial base stock) is between 10 and 100. This latter ratio is called a consolidation ratio.
It has thus been found that a very low silicate concentration, expressed as SiO2, in the initial base stock and an appropriate consolidation ratio during the simultaneous addition stage constitute important conditions for endowing the products obtained with their outstanding properties.
In this embodiment the operation is preferably carried out as follows:
a base stock which includes silicate is formed first of all. The quantity of silicate present in this initial base stock advantageously represents only a proportion of the total quantity of silicate introduced into the reaction.
According to an essential characteristic of the process of preparation according to the invention, the silicate concentration in the initial base stock is lower than 20 g of SiO2 per liter. This concentration is preferably not more than 11 g/l and, possibly, not more than 8 g/l.
The conditions imposed on the silicate concentration in the initial base stock partially determine the characteristics of the silicas obtained.
The initial base stock may include an electrolyte. Nevertheless, preferably, no electrolyte in employed during the process of preparation according to the invention; in particular, the initial base stock preferably does not include any electrolyte.
The term electrolyte is used here in its normally accepted sense, that in to say that it means any ionic or molecular substance which, when in solution, decomposes or dissociates to form ions or charged particles. It is possible to mention as an electrolyte a salt from the group of the alkali and alkaline-earth metal salts, especially the salt of the metal in the original silicate and of the acidifying agent, for example sodium sulphate in the case of the reaction of a sodium silicate with sulphuric acid.
The second stage, consists in adding the acidifying agent to the base stock of the composition described above.
Thus, in this second stage, the acidifying agent is added to the said initial base stock until at least 5%, preferably at least 50%, of the quantity of M2O present in the said initial base stock is neutralized.
In this second stage, the acidifying agent is preferably added to the said initial base stock until 50 to 99% of the quantity of M2O present in the said initial base stock is neutralized.
The acidifying agent may be dilute or concentrated; its normality may be between 0.4 and 36 N, for example between 0.6 and 1.5 N.
In particular, in the case where the acidifying agent is sulphuric acid, its concentration is preferably between 40 and 180 g/l, for example between 60 and 130 g/l.
Once the desired value of the quantity of neutralized M2O has been reached, a simultaneous addition (stage (iii)) of acidifying agent and of a quantity of alkali metal (M) silicate is then performed, such that the consolidation ratio, that is to say the ratio (quantity of silica added)/(quantity of silica present in the initial base stock) is between 10 and 100, preferably between 12 and 50, in particular between 13 and 40.
Throughout stage (iii), the quantity of acidifying agent which is added is preferably such that 80 to 99%, for example 85 to 97%, of the quantity of M2O added is neutralized.
The acidifying agent employed during stage (iii) may be dilute or concentrated; its normality may be between 0.4 and 36 N, for example between 0.6 and 1.5 N.
In particular, in the case where this acidifying agent is sulphuric acid, its concentration is preferably between 40 and 180 g/l, for example between 60 and 130 g/l.
In general, the alkali metal silicate added during stage (iii) exhibits a concentration, expressed as silica of between 40 and 330 g/l, for example between 60 and 250 g/l.
The actual precipitation reaction is finished when the whole remaining quantity of silicate has been added.
It is advantageous to perform a maturing of the reaction mixture, especially after the abovementioned simultaneous addition, it being possible for this maturing to last, for example, for 1 to 60 minutes, in particular for 5 to 30 minutes.
Finally, it is desirable, in a subsequent stage, after the precipitation, especially before the optional maturing, to add an additional quantity of acidifying agent to the reaction mixture. This addition is generally made until a pH value of the reaction mixture of between 3 and 6.5, preferably between 4 and 5.5, is obtained. It makes it possible especially to neutralize the whole quantity of M2O added during stage (iii).
The acidifying agent employed during this addition in generally identical with that employed during stage (iii) of the process of preparation according to the invention.
The temperature of the reaction mixture is usually between 60 and 98xc2x0 C.
The addition of acidifying agent during stage (ii) is preferably done into an initial base stock whose temperature is between 60 and 96xc2x0 C.
According to an alternative form of the invention the reaction in performed at a constant temperature of between 75 and 96xc2x0 C. According to another alternative form of the invention the temperature at the end of reaction is higher then the temperature at the beginning of reaction: thus, the temperature at the beginning of the reaction is preferably maintained between 70 and 96xc2x0 C., and the temperature is then increased during the reaction over a few minutes, preferably up to a value of between 80 and 98xc2x0 C., at which value it is maintained until the end of the reaction.
At the end of the operations which have just been described a silica slurry is obtained, which in next separated off (liquid-solid separation).
In an alternative form, according to another embodiment of the invention, the precipitation (A) is carried out in the following manner:
(i) an initial base stock is formed comprising at least a proportion of the total quantity of the alkali metal (M) silicate introduced into the reaction and an electrolyte, the silicate concentration expressed in SiO2 in the said initial vessel stock being lower than 100 g/l and the electrolyte concentration in the said initial base stock being lower than 17 g/l;
(ii) the acidifying agent is added to the said base stock until a pH value of the reaction mixture of at least approximately 7 is obtained;
(iii) acidifying agent is added to the reaction mixture and, simultaneously, if appropriate, the remaining quantity of the silicate.
It has thus been found that a low silicate and electrolyte concentration in the initial base stock constitute important conditions for endowing the products obtained with their outstanding properties.
In this embodiment the operation is preferably carried out as follows:
a base stock which includes silicate as well as an electrolyte is formed first of all. The quantity of silicate present in the base stock may be either equal to the total quantity introduced into the reaction or may represent only a proportion of this total quantity.
The electrolyte employed is in particular a salt from the group of the alkali and alkaline-earth metal salts and preferably the salt of the metal of the initial silicate and of the acidifying agent, for example sodium sulphate in the case of the reaction of a sodium silicate with sulphuric acid.
According to an essential characteristic of the process of preparation according to the invention the electrolyte concentration in the initial base stock is lower than 17 g/l, preferably lower than 14 g/l.
According to another essential characteristic of the said process the silicate concentration, expressed as SiO2, in the initial base stock is lower than 100 g of SiO2 per liter. This concentration is preferably lower than 80 g/l, especially lower than 70 g/l. In particular, when the acid employed for the neutralization has a high concentration, especially higher than 70%, is in then appropriate to work with an initial base stock of silicate in which the SiO2 concentration is lower than 80 g/l.
The second stage consists in adding the acidifying agent into the base stock of composition described above.
This addition, which produces a corresponding lowering of the pH of the reaction mixture, is made until a value of at least approximately 7, generally between 7 and 8, is reached.
Once this value has been reached, and in the case of an initial base stock including only a proportion of the total quantity of the silicate introduced, a simultaneous addition of acidifying agent and of the remaining quantity of silicate is then advantageously carried out.
The actual precipitation reaction in finished when all the remaining quantity of silicate has been added.
At the end of the precipitation and especially after the abovementioned simultaneous addition it is advantageous to perform a maturing of the reaction mixture, it being possible for this maturing to last, for example, from 5 minutes to 1 hour.
In all cases (that is to say as well in the case of an initial base stock including only a proportion of the total quantity of the silicate introduced) it to also possible, after the precipitation, in an optional subsequent stage, to add to the reaction mixture an additional quantity of acidifying agent. This addition is generally made until a pH value of between 3 and 6.5, preferably between 4 and 6.5, is obtained.
The temperature of the reaction mixture is generally between 70 and 98xc2x0 C.
According to an alternative form of the invention the reaction is performed at a constant temperature of between 80 and 95xc2x0 C. According to another alternative form of the invention the temperature at the end of reaction is higher than the temperature at the beginning of reaction: thus, the temperature at the beginning of the reaction is preferably maintained between 70 and 95xc2x0 C. and then the temperature is increased over a few minutes, preferably up to a value of between 80 and 98xc2x0 C., at which it is maintained until the end of the reaction.
At the end of the operations which have just been described a silica slurry is obtained.
Stage (B) of the process consists in the separation of a precipitation cake from this slurry obtained according to one or other of the operating methods. The separation is performed by any known means and especially by filtration with a belt filter, a filter press, a rotary vacuum filter or by centrifuging. A silica cake is then collected in which the solids content is between 10 and 40%.
The separated cake may be washed with water to remove the alkali metal salts formed during the precipitation reaction. For example, in the case where the precipitation involves sodium silicate and sulphuric acid, a cake which has an Na2SO4 content lower than 1.5% by weight may be isolated at the end of stage (B).
The cakes obtained by press filtration have fairly high solids contents, for example of between 17 and 30%. However, it is also possible to obtain, especially by vacuum filtration, cakes whose solids content is slightly lower, for example between 10 and 15%.
After the separation of the precipitation cake, thickening of the cake may be performed in order to increase its solids content to the desired value of between 10 and 40%.
The thickening consists in adding silica powder in sufficient quantity to the said cake.
In particular, the silica powder may be obtained by drying, especially spray-drying, of a proportion of the cake to be enriched.
It is also possible to obtain a silica powder by performing a conventional drying of the cake after washing with organic solvents. Such a drying process will be described in detail below.
The thickening makes it possible in particular to enrich in silica the cakes which have a relatively low solids content after the filtration (for example lower than 15%), so as to obtain at the end of stage (C) a suspension which is concentrated enough for the intended application.
Stage (C) is then applied to a precipitation cake which has a solids content of between 10 and 40%, obtained, according to the circumstances, after an optional thickening.
The conversion of the cake into less viscous suspension can be carried out by mechanical crumbling. The Crumbling may take place in a crumbler/blender, for example during an operation of dilution of the cake with water, or may be carried out by wet grinding by passing the cake through a grinder of the colloid mill or ball mill type, or by subjecting the cake to ultrasonic waves (ultrasonification). The deagglomeration will preferably be performed under ultrasound by means of a high-power ultrasound probe.
In order to reduce the mechanical energy needed for plasticizing the cakes, it in possible to perform a chemical crumbling at the same time.
For this purpose, advantageously, it is possible to acidify the silica suspension so that its pH is lower than 4. Any acid can be employed for this purpose.
Another advantageous possibility consists in simultaneously introducing into the suspension an acid, especially sulphuric acid, and an aluminium compound, especially sodium aluminate, so that the pH of the suspension remains between 6 and 7 and the Al/SiO2 weight ratio is between 1000 and 3300 ppm.
In an alternative form of the process, in order to increase the solids content of the silica suspension, at the end of the chemical crumbling stage, it is possible:
to perform a second filtration (or centrifuging) stage optionally followed by a wash.
to expel a proportion of the water (for example by evaporation by heating the suspension).
In both these cases it will be possible, at the end of the stage of concentration of the suspension, to carry out a final rehomogenization of the suspension by mechanical crumbling.
In another alternative form of this process it is possible to add the sulphuric acid and the sodium aluminate to the slurry obtained from the precipitation, that is to say after stage (A) (iii) and before the filtration operations (B).
The present invention also proposes another process for conversion (C) of the cake into suspension, whereby:
(i) the said cake is washed with organic solvents and the washed cake is dried to obtain a silica powder and then
(ii) a quantity of the said silica powder is suspended in water, such that the solids content of the final suspension is between 10 and 40%.
The suspensions obtained by this process also exhibit the same properties of low viscosity and high stability with a high solids content.
Washing with organic solvents allows the water present in the pores of the cake to be displaced. The solvents employed for this purpose are preferably polar solvents and in particular ethanol and ether, which can be employed as a mixture.
In particular, it is possible to carry out:
a first washing with ethanol
a second washing with a 50/50 ethanol/ether mixture
a third washing with ether.
Thus washed, the cake may be dried, for example in the open air. A free water content of approximately 6-8% is obtained, which is quite comparable with that obtained with spray-drying.
The present type of drying makes it possible to prevent the collapse of porosity, due to the action of the capillarity forces during the drying.
A powder is thus obtained which is very slightly agglomerated, with a porosity (measured by mercury porosimetry) which is greatly superior to that obtained by spray-drying techniques.
When resuspended in water in quantity such that the solids content of the suspension is between 10 and 40%, this powder produces suspensions which are less viscous than those obtained by resuspending a powder obtained conventionally by spray-drying, and whose viscosity characteristics and particle size are identical with those described above.
The concentrated silica suspensions according to the invention, exhibiting improved rheological and particle size characteristics, can be employed in all applications of silica sols in which the transparency or translucency properties are not necessary.
In this respect, another subject of the invention is the use of the said suspensions as a substitute for silica so is in diverse applications such as:
anticorrosion coatings,
concrete, the silica suspensions being capable especially of accelerating the setting of concretes and/or of improving the mechanical properties;
paper, in which the suspensions can be employed as filler or else as retaining agent for fine fillers and fibres;
inorganic adhesives for paper, cardboard and the building industry.
The present invention in illustrated by the following examples.
In the examples which follow the particle size characteristics of the silica suspensions are determined by virtue of a particle size measurement performed on the suspensions with the aid of a CILAS particle size analyser.
The operating method is as follows:
The suspension is diluted by adding deionized water until an aqueous suspension containing 4% of silica is obtained, which is homogenized for 2 minutes by magnetic stirring.
A known volume (expressed in ml) of the homogenized suspension is introduced into the cell of the particle size analyzer and the particle size measurement is carried out, enabling D50 to be determined.
The ratio (10xc3x97 volume of suspension introduced in ml)/(optical density of the suspension detected by the particle size analyser) is calculated, indicating the content of fin s.
In principle, a volume of suspension is introduced such as to make it possible to obtain an optical density close to 20.
Particle size characteristics of silica powder are also determined in the examples. The operating method is as follows:
2 grams of silica obtained by spray-drying the suspension are weighed into a tablet bottle (h=6 cm and diameter=4 cm) and are made up to 50 grams by adding deionized water. An aqueous suspension containing 4% of silica is thus produced, which is homogenized for 2 minutes by magnetic stirring. The suspension is then deagglomerated using ultrasound.
The suitability of the silica for macro-deagglomeration (break-up of objects from 0.1 to a few tens of microns) is thus measured. The median diameter D50 in deterred in the same way, as is the above ratio, which is then the ultrasonic deagglomeration factor FP.
The ultrasonic deagglomeration is carried out with the aid of a VIBRACELL BIOBLOCK (600 W) sonic transducer equipped with a 19-mm diameter probe, as follows:
with the probe immersed over a length of 4 cm, the output power is adjusted so as to obtain a displacement of the power dial needle indicating 20% (which corresponds to an energy dissipated by the probe tip of 120 watts/cm2). The deagglomeration is performed for 420 seconds.
The particle size measurement is performed as above, but with a SYMPATEC laser scattering particle size analyser.

Concentrated suspension of precipitation silica, processes for its preparation and uses of this suspension

Abstract: This suspension can be employed for the production of anticorrosion coatings and for the preparation of concretes, of paper or of inorganic adhesives.


A remote controller 101 includes: an operation unit 11; a power generating unit 12 that generates electric power by operation on the operation unit 11; a signal generating unit 13 that operates by using the electric power generated by the power generating unit 12 and is able to output a signal of a kind corresponding to the content of each operation on the operation unit 11; a storage unit 15 that operates by using the electric power generated by the power generating unit 12 and nonvolatilely stores the content of an output signal of the signal generating unit 13; and a transmission control unit 14 that operates by using the electric power generated by the power generating unit 12 and transmits a wireless signal including information corresponding to the content of the output signal stored in the storage unit 15 when the operation on the operation unit 11 satisfies a predetermined condition.

There has been developed an instrument that operates by using electric power generated by energy harvesting for harvesting minute energy from a surrounding environment such as light, heat, and oscillation.
For example, Japanese Patent Publication No. 4824277 (Patent Literature 1) discloses the following technique.
That is, a sensor system includes: at least one voltage generator that converts nonelectric energy into electric energy; at least one energy storage unit connected to a back position of the voltage generator; at least one voltage converter connected to the energy storage unit so that an output signal of the self matches the operation performed by a processor control unit; at least one sensor; and at least one transmission unit that performs wireless transmission of a transmission telegram which is generated by the processor control unit and which includes at least one measured value of the at least one sensor.
In the sensor system, there is provided a semiconductor timer circuit configured by the ULP technique that realizes a long-hour active cycle in the case where the energy supply is imperfect.
The timer circuit is triggered when the voltage of the at least one energy storage unit reaches a predetermined level. After a predetermined time since the time point when the timer circuit is triggered, the timer circuit starts the processor control unit and the transmission unit so as to transmit at least one transmission telegram.
The at least one voltage generator is configured in a size in which the voltage generator cannot generate sustainably-operating electric power, even when the voltage generator attempts to directly drive the processor control unit. The transmission telegram further includes one identification code.

Remote controller and remote control system


The present invention includes a client-server security system. The client-server security system includes a client system receiving first biometric data and having a first level security authorization procedure. In one embodiment, the first biometric data is speech data and the first level security authorization procedure includes a first speaker recognition algorithm. A server system is provided for receiving second biometric data. The server system includes a second level security authorization procedure. In one embodiment, the second biometric data is speech data and the second level security authorization procedure includes a second speaker recognition algorithm. In one embodiment, the first level security authorization procedure and the second level security authorization procedure comprise distinct biometric algorithms.

The present invention relates to systems and methods for implementing security features into electronic systems. More particularly, the present invention relates to security systems and methods implemented in a client-server system utilizing biometrics.
FIG. 1 illustrates a typical client-server system 100. Client-server systems typically include a client system 110 coupled to a server system 130 by a communication channel 120. The server system 130 may then be coupled to remote resources 140. For example, the server system may be coupled to remote resources over a network 150, such as a local area network, a wide area network, telecommunications network, or other types data communications networks. The remote resources may be additional server systems, data storage networks, or other types of data processing systems.
In the client-server system 100, a user will typically access resources on the server system 130 or remote resources 140 through the client system 110. However, one problem associated with client-server systems is that security on such systems can be difficult to implement effectively. For example, a particular user of a client system 110 may wish to carry out operations or transactions on the server system 130 or remote resources 140 in a secure environment. Traditional security systems for establishing a secure environment on a client-server system have either implemented security features solely into the server system 130 or solely into the client system 110. However, security systems implemented solely on the server system 130 have the disadvantage of being susceptible to hacking or other forms of electronic attack. Additionally, such systems require that security data be sent across a transmission medium which may result in degradation or distortion of the data, thereby leading to a reduction in the quality of the security data and a compromise of the integrity of the security system. On the other hand, security systems implemented solely on the client system 110 have the disadvantage of being constrained by the limited resources of the client system 110.
Therefore, what is needed is a more effective system and method for ensuring a secure environment for a user of a client-server system.

Biometric client-server security system and method


This injector head 1000 comprises a plunger 20 capable of reciprocating in a direction of movement of a piston 1a in a syringe 1, a plunger drive 500 for converting rotary motion of a plunger motor 2 to linear motion in order to supply reciprocation to this plunger 20, and a safety device 600 as safety means for restraining rotation of a rotary shaft 2a of the plunger motor 2 when the plunger 20 moves beyond a predetermined position. Thus, it is possible to provide a medical injector head attaining miniaturization and simplification of the apparatus while keeping a mechanical safety mechanism.

The present invention relates to a mechanical locking mechanism and an injector head employing the mechanism, and more specifically, it relates to an improvement of a structure for attaining miniaturization of a mechanical locking mechanism and an injector head employing the mechanism.
In recent years, various ones are developed as apparatuses testing functions of a human body. There is a circulatory organ X-ray diagnostic apparatus for diagnosing the functions of circulatory organs of a human body as one of these apparatuses. In this circulatory organ X-ray diagnostic apparatus, an injector head for injecting a contrast medium into a patient is employed.
According to the structure of a general injector head, a safety device for mechanically limiting movement of a plunger for moving a piston in a syringe filled with a contrast medium is provided. When providing this safety device on the injector head, the injector head tends to be large-sized.
In an injector head disclosed in Japanese Patent Laying-Open No. 10-244002, on the other hand, a structure attaining miniaturization of the injector head by providing a mechanical stopper arranged coaxially with a plunger for sliding in the axial direction of the plunger is employed.
According to the structure of the aforementioned conventional injector head, however, the structure of mechanically stopping the plunger having the largest torque itself with the mechanical stopper is employed. When mechanically stopping the plunger with the mechanical stopper, therefore, stress applied to the plunger, the mechanical stopper and other components increases.
Consequently, it forms the design basis to withstand this stress in strength design of the components such as the plunger subjected to application of the stress, and size increase of these components cannot be avoided. Consequently, there is a limit in the point of attaining miniaturization of the injector head.
Accordingly, an object of the present invention is to attain further miniaturization and simplification of a mechanical locking mechanism and an injector head employing the mechanism while keeping a mechanical safety mechanism of the mechanical locking mechanism and the injector head employing the mechanism.
In a mechanical locking mechanism based on the present invention, it is a mechanical locking mechanism for stopping a movable shaft capable of reciprocation, and comprises a movable shaft drive for converting rotary motion of a drive to motion of a prescribed direction in order to supply reciprocation to the aforementioned movable shaft and a safety device for restraining rotation of a rotary shaft of the aforementioned drive by a mechanical operation when the aforementioned movable shaft moves beyond a predetermined position.
Thus, torque caused on the rotary shaft of the drive is by far smaller than torque caused on the movable shaft, and hence it is possible to stop movement of the movable shaft with small force by restraining rotation of the rotary shaft of the drive by a mechanical operation. Therefore, stress applied to components forming the safety device also reduces and it is possible to attain miniaturization of these components and miniaturization of the mechanical locking mechanism following the same.
In order to execute the aforementioned invention in a preferable state, the following structure is employed: The aforementioned safety device includes a locking device provided in the vicinity of the aforementioned rotary shaft to be capable of restraining rotation of the rotary shaft of the aforementioned drive and a trigger device mechanically operating the aforementioned locking device so that the aforementioned locking device restrains the aforementioned rotary shaft when the aforementioned movable shaft moves beyond the predetermined position.
Further, the aforementioned locking device is provided to be capable of selecting a first position restraining rotation of the aforementioned rotary shaft and a second position liberating rotation of the said rotary shaft, and the aforementioned trigger device includes a detection mechanism for mechanically detecting a moving end of the aforementioned movable shaft and a link mechanism setting the aforementioned locking device on the first position by the aforementioned detection mechanism when the aforementioned movable shaft moves beyond the predetermined position.
This structure makes detection of the position of the movable shaft implementable by the detection mechanism consisting of only a mechanical structure, whereby safety of the operation of the mechanical locking mechanism can be attained regardless of a failure of electric control.
In an injector head based on the present invention, it is an injector head provided therein with a syringe filled with a contrast medium, and comprises a plunger capable of reciprocating in a direction of movement of a piston in the aforementioned syringe, a plunger drive for converting rotary motion of a motor to linear motion in order to supply reciprocation to the aforementioned plunger and a safety device for restraining rotation of a rotary shaft of the aforementioned motor by a mechanical operation when the aforementioned plunger moves beyond a predetermined position.
Thus, torque caused on the rotary shaft of the motor is by far smaller than torque caused on the plunger, and hence it is possible to stop movement of the plunger with small force by restraining rotation of the rotary shaft of the motor by a mechanical operation. Therefore, stress applied to components forming the safety device also reduces and it is possible to attain miniaturization of these components and miniaturization of the injector head following the same.
In order to execute the aforementioned invention in a preferable state, the following structure is employed: The aforementioned safety device includes a locking device provided in the vicinity of the aforementioned rotary shaft to be capable of restraining rotation of the rotary shaft of the aforementioned motor and a trigger device mechanically operating the aforementioned locking device so that the aforementioned locking device restrains the aforementioned rotary shaft when the aforementioned plunger moves beyond the predetermined position.
Preferably, the aforementioned locking means is provided to be capable of selecting a first position restraining rotation of the aforementioned rotary shaft and a second position liberating rotation of the aforementioned rotary shaft, and the aforementioned trigger device includes a detection mechanism for mechanically detecting a moving end of the aforementioned plunger, and a link mechanism setting the aforementioned locking device on the first position by the aforementioned detection mechanism when the aforementioned plunger moves beyond the predetermined position.
This structure makes detection of the position of the plunger implementable by the detection mechanism consisting of only a mechanical structure, whereby safety of the operation of the injector head can be attained regardless of a failure of electric control.
As a further preferable mode in the aforementioned mechanical locking mechanism and injector head, the aforementioned locking device includes a fixed lock ring provided around the aforementioned rotary shaft and including a groove portion having such a sliding surface that the distance between the sliding surface and the center of the aforementioned rotary shaft gradually shortens along a prescribed rotational direction of the aforementioned rotary shaft on a side facing the aforementioned rotary shaft, a lock pin arranged in the aforementioned groove portion and a movable lock ring holding the aforementioned lock pin to be movable between a first position locating the aforementioned lock pin between a surface of the aforementioned sliding surface most shortening the distance between the sliding surface and the aforementioned rotary shaft and the aforementioned rotary shaft and restraining rotation of the aforementioned rotary shaft by a wedge effect and a second position liberating rotation of the aforementioned rotary shaft in the aforementioned groove portion.
Further, the aforementioned detection mechanism includes a follower rotary shaft rotating following rotation of the aforementioned drive or the aforementioned motor, a body plate having the same rotation center as the rotation center of the aforementioned follower rotary shaft, a first gear having the same rotation center as the rotation center of the aforementioned follower rotary shaft, to which rotation of the aforementioned follower rotary shaft is transmitted through a first gear mechanism supported on the peripheral portion of the aforementioned body plate and a second gear having the same rotation center as the rotation center of the aforementioned follower rotary shaft, having a specific rotation control mechanism and arranged to be opposite to the aforementioned first gear, a surface of either one of the aforementioned first gear and the aforementioned second gear opposed to the other gear is provided with a pin projecting toward the other gear, a surface of the other gear opposed to one of the gears is provided with a ring-shaped guide slit having both end portions and extending along the rotation locus of the pin to be capable of receiving the aforementioned pin, and the aforementioned link mechanism has an engaging pin provided on the aforementioned movable lock ring, an operating mechanism provided to be rotatable about a prescribed axis for rotating the aforementioned movable lock ring so that the aforementioned lock pin is on the first position with an end engaging with aforementioned engaging pin and a link bar having an end coupled to the peripheral portion of the aforementioned body plate by a universal joint and another end coupled to the other end of the aforementioned operating mechanism by a universal joint.
Further, the aforementioned operating mechanism has an electric signal generator converting movement of the aforementioned operating mechanism to an electric signal.
In addition, the aforementioned trigger device has a device limiting the stroke of the aforementioned movable shaft or the aforementioned plunger.

Mechanical lock mechanism and injector head using the mechanism


The present invention relates to a genetic marker for determining meat quality traits of pigs and a use thereof, and specifically, a genetic marker for determining meat quality traits of pigs, comprising a polynucleotide consisting of 5 to 300 consecutive nucleotides comprising the nucleotides from the 1524th to the 1527th positions in the polynucleotide of SEQ ID NO: 1, or a polynucleotide complementary thereto, a composition for determining meat quality traits of pigs comprising an agent capable of detecting the genetic marker, a composition for determining Korean native pigs, a kit, a microarray, a method for determining meat quality traits of pigs, and a method for determining meat quality traits of Korean native pigs. The genetic marker of the present invention is a specific marker for determining the meat quality traits of pigs, and thus the marker can be used not only as a means for the objective evaluation of meat quality traits of pigs that cannot be determined by the naked eye but also as a means for distinguishing between foreign pigs and Korean native pigs, and is thereby capable of contributing to the establishment of distribution order of pork meat.

There are about 200 breeds of pigs worldwide. Among them, European breeds account for about 33% and Asian breeds account for about 30%. These pig breeds can be easily distinguished based on phenotypic differences such as hair color, size, body shape, etc. However, in the case of lean meat, color, water-holding capacity, shearing force, etc., they vary with time and thus it is difficult even for specialists as well as ordinary people to distinguish pig breeds by the naked eye based on the meat of pigs. Recently, many efforts have been made to improve the quality of pig meat. Pigs are now being bred in Korea under certain standards or management using a scientific system, and Korean native pigs obtained as such are branded, and various brands of pig meat are already commercially available.
As part of this study, active studies are being conducted in the direction of discovering and developing methods to identify the breeds of pork meat using various DNA analysis methods. For example, Korean Patent Application Publication No. 10-2004-0039059 discloses a genetic detection method for selecting pigs with excellent phenotypic traits using specific DNA markers related to average daily gain, backfat thickness, and meat quality of pigs, and Korean Patent Application Publication No. 10-2007-0113336 discloses a DNA marker for detecting the increase in the number of pig muscle cells using single nucleotide polymorphism (SNP) by the difference in a single nucleotide sequence in the 5′ promoter region of myogenin gene, which is known to be involved in myogenesis of pigs. However, the method for accurately determining the level of meat quality traits of pigs has not yet been developed, and additionally, the method for determining the level of meat quality of pigs using MYH3 gene has not been developed.
Under these circumstances, the present inventors have made efforts to develop a method for determining the quality of pork meat through genetic traits. As a result, they have confirmed that MYH3 gene is a gene capable of determining the meat quality of pigs and that it is possible to easily determine the meat quality of pigs determined genetically using the same, thereby completing the present invention.

Genetic marker for determining meat quality traits of pigs and use thereof

REPUBLIC OF KOREA (MANAGEMENT: RURAL DEVELOPMENT ADMINISTRATION)

KOREA RESEARCH INSTITUTE OF BIOSCIENCES AND BIOTECHNOLOGY

JEJU NATIONAL UNIVERSITY INDUSTRY-ACADEMIC COOPERATION FOUNDATION


A method of optical element manufacturing, the method may include selecting a range of a misfocus parameter ψ; and designing the optical element to include multiple regions, wherein the optical transfer function (OTF) of the optical element allows, for the range of the misfocus parameter .psi., transmission of images with a contrast of at least 10% for all normalized spatial frequencies up to 50% of a theoretical maximum that is attainable with a full aperture in an in-focus condition.

The present invention relates to optical imaging and, more particularly, to a mask for insertion in the pupil of an optical imaging system that provides extended depth of field for imaging scenes located in the extended depth of field region and illuminated by incoherent light without needing to process the image created by the imaging system that incorporates the mask.
Imaging systems are known to require accurate focus alignment. Conventional imaging systems, for example cameras, are very sensitive to misfocus. When the object and image planes are not in conjugate positions, the resultant image is severely degraded. Nevertheless, there are many applications (e.g. barcode reading, computer or machine vision, surveillance cameras, etc.) that require imaging of objects located anywhere within an extended depth of field (DOF) region, while allowing reduced contrast and resolution.
Conventional solutions for imaging systems with an extended DOF involve pupil stopping and apodization. See, for example, M. Mino and Y. Okano, "Improvement in the OTF of a defocused optical system through the use of shaded apertures", Applied Optics vol. 10 pp. 2219-2225 (1971); J. O. Castaneda et al., "arbitrary high focal depth with a quasioptimum real and positive transmittance apodizer", Applied Optics vol. 28 pp. 2666-2669 (1989); J. O. Castaneda and L. R. Berriel-Valdos, "Zone plate for arbitrary high focal depth", Applied Optics vol. 29 pp. 994-997 (1990). The main disadvantages with such solutions are reduced resolution and low light throughput.
Recently, a hybrid opto-electronic approach has been proposed, to solve such problems. See, for example, E. R. Dowski, Jr. and W. T. Cathey, "Extended depth-of-field through wave-front coding", Applied Optics vol. 34 (1995) pp. 1859-1866, and J. van der Gracht et al., "Broadband behavior of an optical-digital focus-invariant system", Optics Letters vol. 21 no. 13 (1996) pp. 919-921. Both of these references are incorporated by reference for all purposes as if fully set forth herein. In that approach, a non-absorptive phase mask is used to severely aberrate, or encode, the wavefront of the light wave at the pupil. The aberration distorts the obtained image (sometimes referred to as the "intermediate image"), often so much that the intermediate image is unidentifiable. Nevertheless, the intermediate image is insensitive to misfocus for a wide range of DOF. Image acquisition is followed by a digital signal-processing (DSP) step to recover the final image from the intermediate image. Another approach, by W. Chi and N. George ("Computational imaging with the logarithmic asphere: theory", Journal of the Optical Society of America vol. 20 pp. 2260-2273 (2003)) produces distorted images that change with misfocus position. An iterative filter is used in this case to restore the image so as to finally provide imaging with a certain enhanced depth of field. The main advantages of such approaches are that there is no reduction in light power collection, and that theoretically, one can restore the image details up to the optical cutoff spatial frequency. Practically, resolution is limited by CCD pixel size, as well as by the presence of noise, which may even be amplified in the processing stage.
We have proposed a phase mask that consists of sixteen spatially multiplexed Fresnel lenses. See E. Ben-Eliezer et al., "All-optical extended depth of field imaging system", Journal of Optics A: Pure and Applied Optics vol. 5 (2003) pp. S164-S169, which reference is incorporated by reference for all purposes as if fully set forth herein. Although the corresponding all-optical imaging system has an extended DOF, this imaging system is suboptimal for scenes illuminated by incoherent light.
There is thus a widely recognized need for, and it would be highly advantageous to have, a mechanism, for extending the DOF, such mechanism being optimized for incoherent illumination and not requiring postprocessing.

Optical mask for all-optical extended depth-of-field for imaging systems under incoherent illumination


A lever-type connector includes: a first housing; a second housing capable of fitted to and removed from the first housing; a lever rotatably supported by the second housing for fitted to and removed the first housing and the second housing by a rotation operation; a support shaft provided on the second housing; a bearing portion provided on the lever and comprising a shaft sliding groove for sliding the support shaft; a cam follower provided on the lever; a cam groove provided on the first housing, the cam groove to which the cam follower is engageable; a guide protrusion provided on the second housing, and a guide groove provided on the lever, the guide groove to which the guide protrusion is engageable. When the first housing and the second housing are completely fitted by the rotation operation of the lever, the lever becomes slidable with respect to the second housing.

As this type of lever-type connector, there is one disclosed in PTL 1 (JP 2002-359035 A).
Such a conventional lever-type connector disclosed in PTL 1 includes: a male housing having a shaft portion and an arc-like pushing portion on each side surface; a female housing that can be fitted to and removed from the male housing and is provided with a cam follower on each side surface; and a lever having a bearing hole fitted to the shaft par, a cam groove in which the cam follower is engaged, and an anti-cantilever type movement detection portion that rides on the pushing portion when the lever is in a semi-fitting state, each provided on each of a pair of arms extending from each end of an operation part.
Then, when the lever is rotated by a pressing operation of the operation part, the cam groove of the lever moves along the cam follower, and the male housing and the female housing are fitted each other. Also, if the male housing and the female housing are incompletely fitted and are not yet fitted, and if you try to fit the lever-type connector into a mounting hole of a vehicle body panel, the movement detection portion rides on the pushing portion thus the movement detection portion elastically deforms to the outside of the outer surface of the arm and protrudes. In this state, the movement detection portion interferes with the mounting hole, the lever-type connector cannot be fitted into the mounting hole, and is detected that the male housing and female housing are in a semi-fitted state.


An apparatus for discriminating the authenticity of a bill put into an automatic vending machine, etc. on the basis of a degree of brilliance of a surface of the bill, comprises two photodiodes for receiving light irradiated from a light-emitting diode and reflected by the bill, and a polaroid filter disposed in front of one of the photodiodes. A differential amplifier or a divider is supplied with output currents from the photodiodes, respectively representing an amount of the reflected light received not through the polaroid filter and containing a polarized component which is produced when the light is reflected on the surface of the bill, and an amount of the reflected light, received through the filter and containing no polarized component, and generates an output voltage indicative of the difference between or the ratio of the output currents, which voltage is compared with a corresponding reference voltage in a comparator whose output assumes a Low-level for a lusterless authentic bill, and a High-level for a brilliant counterfeit bill obtained by color-copying the authentic bill, whereby the authenticity of the bill is accurately discriminated.

The present invention relates to a method for discriminating the authenticity of a bill and an apparatus therefor for use in automatic vending machine, automatic service machine, automatic exchanger, automatic cash dispenser, etc.
An automatic vending machine or the like is required to discriminate the authenticity of a bill put into the machine. To this end, conventionally, the machine is equipped with an apparatus for discriminating the authenticity of a bill, which comprises, for instance, a light source for irradiating light onto the bill, and a light-receiving element for receiving reflected or transmitted light from the bill, and which operates to discriminate the authenticity of the bill on the bass of a level of an output of the light-receiving element. In another prior art (see, Japanese Provisional Patent Publication No. 62-296292), two color components of the reflected light are separately detected, so as to determine a color of the bill on the basis of respective detected levels of the two color components, to thereby discriminate the authenticity of the bill. A still another prior art is known (see, Japanese Provisional Patent Publication No. 62-276685), which is arranged to discriminate an authentic bill from a counterfeit bill obtained by color-copying the authentic bill on the basis of an output of a light-receiving element, which receives a regularly reflected light from a surface of a bill, and that of another light-receiving element which receives an irregularly reflected light therefrom.
However, on one hand, the light source and the light-receiving element change is their characteristics as an ambient temperature varies, and on the other hand, a thrown bill also includes variable factors such as freshness/oldness of the bill, presence/absence of wrinkles and stains in the bill. Accordingly, a difficulty is encountered in setting a reference level in case that discrimination of the authenticity of a bill is effected on the basis of an output of the light-receiving element. Namely, if the reference level is strictly set to a level close to the authentic-bill-side, an authentic bill is sometimes erroneously determined as a counterfeit bill. On the contrary, if the reference level is loosely set to a level close to the counterfeit-bill-side, a counterfeit bill can be erroneously determined as an authentic bill. In this manner, according to prior art, a difficulty arises in eliminating an incorrect discrimination. Particularly, it is difficult to accurately discriminate an authentic bill from a sophisticated counterfeit bill which is obtained by color-copying the authentic bill.

Method for discriminating authenticity of a bill using polarization and an apparatus therefor


A method and apparatus is provided for control of plural optical phase shifters in an optical device, such as a Mach-Zehnder Interferometer switch. Drive signal magnitude is set using a level setting input and is used for operating both phase shifters, which may have similar characteristics due to co-location and co-manufacture. A device state control signal selects which of the phase shifters receives the drive signal. One or more switches may be used to route the drive signal to the selected phase shifter. Separate level control circuits and state control circuits operating at different speeds may be employed. When the phase shifters are asymmetrically conducting (e.g. carrier injection) phase shifters, a bi-polar drive circuit can be employed. In this case, the phase shifters can be connected in reverse-parallel, and the drive signal polarity can be switchably reversed in order to drive a selected one of the phase shifters.

To meet continued growth in data network traffic demands, new data switching technologies with large switching capacities and high interconnect bandwidths are required. Optical switching systems represent one such technology. Silicon-on-insulator (SOI) technologies provide a low-cost platform for high-performance optical switching technologies for data center communication applications. For such applications, switches that are high-speed, broadband, low crosstalk, and have low-power consumptions are desired.
On an SOI platform, optical devices (such as but not necessarily limited to devices including Mach-Zehnder interferometers (MZI)) that have carrier injection phase shifters operating in a push-pull configuration are commonly used for high-speed switches and other applications. While providing an efficient optical phase shift with speeds up to potentially hundreds of megahertz, carrier injection also produces inherent insertion loss due to free-carrier absorption. Further, due to fabrication imperfections and non-uniformities, there is phase error and power imbalance between waveguide arms of the MZI, resulting in some light leakage at the unwanted output port, which in turn causes insertion loss, optical crosstalk, and reduced extinction ratio.
Therefore, there is a need for an optical device such as an optical switch, and method and apparatus for controlling same, that obviates or mitigates one or more limitations of the prior art.
This background information is provided to reveal information believed by the applicant to be of possible relevance to the present disclosure. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present disclosure.

Method and apparatus for control of optical phase shifters in an optical device


An attachment system, an air bag module subassembly and a method of attachment are provided for the fastenerless attachment of an inflatable cushion into a restraint system. A thickened gas inlet opening of the inflatable cushion is secured within a channel portion of a cushion retainer to form a cushion/retainer subassembly wherein the secured inlet opening forms an attachment insert. The attachment insert is inserted into an attachment sleeve portion of the reaction housing to secure the cushion to the housing.

This invention relates generally to inflatable restraint systems and, more particularly, to the retention of an inflatable cushion, commonly referred to as an air bag, in such systems.
Safety restraint systems which self-actuate from an undeployed to a deployed state without the need for intervention by the operator, i.e., "passive restraint systems", and particularly those restraint systems incorporating inflatable bags or cushions, as well as the use of such systems in motor vehicles have been the subjects of much discussion as the desirability of the use of such passive restraint systems has gained general acceptance in the United States.
It is well known to protect a vehicle occupant using a cushion or bag that is inflated with gas, e.g., an "air bag", when the vehicle encounters sudden deceleration, such as in a collision. The term "air bag" is something of a misnomer, however, as during deployment the rapidly evolving gas with which the bag is filled is typically not air but rather an inert gas, e.g., nitrogen. In such systems, the cushion is normally housed in an uninflated and folded condition to minimize space requirements. In an emergency, gas is discharged from an inflator to rapidly inflate the bag. The cushion, upon inflation, serves to restrain the movement of the vehicle occupant as the collision proceeds. In general, such air bags are commonly designed to be inflated in no more than about 45-60 milliseconds.
Vehicular inflatable restraint systems generally include multiple crash sensors generally positioned about or mounted to the frame and/or body of the subject vehicle and serve to sense sudden decelerations by the vehicle. In turn, the sensor sends a signal to an inflatable air bag/cushion module or assembly strategically positioned within the riding compartment of the vehicle to actuate deployment of the cushion. In general, an inflatable cushion provided for the protection of a vehicle driver, i.e., a driver side air bag, is mounted in a storage compartment located in the steering column of the vehicle. Whereas, an inflatable cushion for the protection of a front seat passenger, i.e., a passenger side air bag, is typically mounted in the instrument panel/dash board of the vehicle.
Typical inflatable cushion restraint systems make use of an air bag module which generally includes an outer reaction housing or canister, commonly referred to as a "reaction can" or, more briefly, as a "can". The reaction canister generally serves to support or contain other components of the air bag module system, including what is referred to as a "air bag inflator" or, more briefly, as an "inflator" or, alternatively, as a "generator". The inflator, upon actuation, acts to provide the gas to inflate the air bag/cushion.
Inflators used in such systems are typically either of a pyrotechnic or hybrid type. Pyrotechnic inflators generally contain a gas generating material which, upon activation, generates gas used to inflate the air bag/cushion. In general, the inflation gas produced by a pyrotechnic inflator is emitted from openings or emission ports along the length of the inflator. In contrast, hybrid type inflators in addition to a body of ignitable pyrotechnic material generally contain as the primary inflation gas a stored, compressed gas which, upon proper actuation, is expelled from the inflator. As a consequence of the physics associated with the storage of compressed gases, the container used to store this compressed gas typically has a cylindrical shape. Furthermore, the discharge of gas from such a cylindrically shaped gas storage container typically occurs by way of openings or emission ports at only one end of the cylindrical container. To attain proper bag deployment, however, it is generally desired that the emission of gas into the air bag/cushion from such a storage container be done in a fairly uniform manner. With typical air bag/inflator assemblies, such uniform emission is generally attained by having a relatively even emission of gas into the deploying bag along the length of the gas inlet opening of the bag connected, directly or indirectly, to the inflator. In this way the bag is properly uniformly deployed and the risk of the bag deploying in a skewed manner due to the discharge of gas from only one end of the storage container is avoided.
The reaction housing typically is an open-mouthed container into which the air bag/cushion, in an uninflated and folded condition, is also placed. In practice and in prior art devices, the component parts of such inflatable restraining devices, particularly the inflatable air bag and the housing, are commonly joined and held together through the use of a multiple number of selected fasteners such as screws, rivets or bolts.
For example, a selected fastener is typically passed through fastener holes which have been preformed in the respective parts to be fastened together. Unfortunately, a problem frequently experienced in the assembly of these inflatable restraining units is difficulty in achieving and maintaining desired and proper fastener hole alignment of the respective parts to be fastened together. Also, in order to avoid undesired point loading of the stresses generated upon bag deployment, it is generally preferred to secure or fasten the bag into the assembly by means of fastening the bag between two load bearing materials (e.g., metals), such as between the reaction canister and metal retaining flanges or a metal ring placed about the gas inlet opening of the bag, for example. In this way, undesired loading of bag deployment stresses at or about the fastener holes in the bag fabric is reduced and preferably avoided.
In general, such fastening is done through the reaction canister itself, thereby simplifying the assembly process as the canister, bag and metal retaining flanges or metal ring are all simultaneously fastened together by means of such fastening. Unfortunately, it is difficult to simultaneously maintain proper alignment of the fastener holes in the canister, bag and retaining flange as the fastener holes in the relatively flexible bag material tend to become easily displaced relative to the fastener holes in the canister and/or retaining flange. As a result, an assembly worker must either be dedicated to maintaining the fastener holes in proper alignment or else a worker will have to stop whatever else that worker was doing in order to realign the fastener holes in the bag with the fastener holes in the canister and in the retaining flange. This of course slows and increases the cost of the assembly process. Further, a requirement for human intervention to reeffect proper fastener hole alignment prevents implementation of a more fully automated assembly process.
Furthermore, each fastener is an entity in and of itself with each such fastener needing to be tightened to a specific torque, thereby complicating the assembly process. For example in order to better ensure safety in and proper functioning of air bag module assemblies, the component parts of the assembly, including fasteners, and the particulars of each such use of a component part is desirably recorded and tracked. Such recording and tracking operations, however, are undesirably complicated as the number of component parts of the assembly is increased. In view thereof, air bag module assemblies are generally preferably designed to minimize the number of component parts used therein.
In addition, common fasteners such as screws, bolts and rivets, include a protruding head portion. Thus in systems which utilize such fastening means, the system must be designed to allow for such protrusions. In inflatable restraint systems, however, space comes at a premium and thus such systems are preferably designed seeking to minimize space requirements.
Also, fasteners, specifically portions thereof such as the protruding head, can undesirably snag objects with which they come into contact with. The creation of such snags in an inflatable air bag not only detrimentally effects the aesthetics of the system but, dependent upon the extent and location of the snag(s) could jeopardize the proper functioning of the system.
Thus, there are a number of U.S. patents that at least in part relate to cushion attachment and retaining mechanisms which avoid or reduce the use of or reliance upon fasteners such as rivets, bolts, and screws and, in turn, avoid or reduce the occurrence of the problems associated with the use of such fasteners.
For example, U.S. Pat. No. 4,941,678, Lauritzen et al., issued Jul. 17, 1990, discloses a lightweight housing canister assembly wherein notches formed on the inner side of each of the walls of the reaction canister body form a bag retaining ring shelf for retaining a continuous attachment ring formed at the gas inlet opening of the inflatable bag. Without the use of some sort of fastener, the retaining of such a continuous attachment ring onto the bag retaining shelf could pose a problem.
U.S. Pat. No. 4,986,569 discloses an air bag attachment system comprising a canister having a shoulder on a peripheral edge flange for seating of a metal rod disposed in a channel in the air bag. The edge flange of the canister is reentrantly folded about the rod to retain the air bag on the canister. Upon bag deployment, the reentrantly folded flange of the canister would appear susceptible to unfolding and to subsequent release of the metal rod disposed in the air bag channel. In addition, the edge of such a folded flange of the canister would appear to contact the air bag upon deployment thereof. As such an edge can form a relatively sharp edge surface, contact of the bag therewith could likely result in a tearing of the bag fabric and consequent failure by the system.
U.S. Pat. No. 5,069,480 though relying on the inclusion of a multiple number of fasteners, e.g., rivets "196", in securing an air bag to a retainer, discloses an air bag retainer assembly which includes a pillow or air bag assembly including a pillow retainer to which is attached an inflatable pillow or air bag and which retainer is secured to the reaction housing assembly. Gas, supplied upon activation of a gas generator, will flow through openings provided in the retainer and into the pillow or air bag. The air bag is secured to the retainer by means of both:
a) a fastener such as a rivet inserted within openings through the fabric of the air bag and into a corresponding opening in the retainer, and PA1 b) a V-shaped hem sewn about the end of the bag and which upon movement of the hem and air bag forward engages and envelopes the circumferential edge of the retainer. PA1 a) securing a thickened peripheral gas inlet opening of an inflatable cushion in a channel portion of a cushion retainer to form a cushion/retainer subassembly, wherein the secured gas inlet opening forms a male mating member attachment insert; and PA1 b) inserting the male mating member attachment insert in a female mating sleeve portion of the reaction housing member to effect joinder of the subassembly with the reaction housing member. PA1 a) the thickened peripheral gas inlet opening of the inflatable cushion contains a bead material and PA1 b) the reaction housing member is at least in part made of an extruded metal with the sleeve portion integrally formed therewith.
U.S. Pat. No. 4,877,264 discloses the sewing into place, in the bag mouth, an elastomeric o-ring bead material. The bead material is configured and adapted to fit into a groove in the outer surface of a retainer ring. To effect engagement, the locking bead is stretched over a flanged upper lip portion of the retaining ring. The mouth of the bag is then permitted to contract back into the grooved portion of the ring.
Examples of other such patents include: U.S. Pat. No. 4,111,457 which discloses the use of a clamping ring to secure the edge of an air bag to the housing of the inflatable restraining device; and U.S. Pat. No. 5,058,919 which discloses an air bag module construction and assembly technique wherein a screen-shaped member is used to retain a folded air bag in the housing.
Thus, a relatively simple, low cost cushion attachment and retaining mechanism which: 1) avoids the use of fasteners such as rivets, bolts, and screws and the problems associated with the use of such fasteners, such as those identified herein and 2) which mechanism permits an easy adaptation to automated production and assembly is desired.

Air bag retention in inflatable restraint systems


Embodiments of this application provide a discontinuous reception DRX management method, including determining, by a base station, that a terminal has a voice service, and setting up, by the base station, a voice bearer for the terminal, and activating a DRX function of the terminal when setting up the voice bearer for the terminal. It can be learned that, in the method, the terminal does not activate the DRX function before setting up the voice bearer, and does not activate the DRX function until the voice bearer is set up, to effectively reduce a voice paging connection delay.

Different communications networks have different bearer mechanisms for a voice service. For example, in the second generation mobile communications technology or third generation mobile communications technology network, a voice service is carried in circuit switched (CS) domain. For another example, in a Long Term Evolution (LTE) system, a voice service is carried in packet switched (PS) domain. The voice service is packetized, like other service data, into an Internet Protocol (IP) data packet for transmission, thereby implementing end-to-end voice communication. Compared with a CS domain network, a PS domain network can provide a user with a faster voice service of higher quality.
A service data flow usually has a burst characteristic: There is data transmission in a period of time, but there is no data transmission in a next period of time. Based on this, a discontinuous reception (DRX) mechanism is introduced, to reduce energy consumption of a terminal. In the mechanism, the terminal stops listening on a physical downlink control channel (PDCCH) in a period of time (which may be referred to as a dormant period), and listens on the PDCCH only when entering an active state. In this way, the terminal does not need to continuously listen on the PDCCH, thereby reducing energy consumption of the terminal.
However, in a voice call process, introduction of the DRX technology increases a voice call connection delay, deteriorating user experience.

Management of discontinuous reception (DRX) for a terminal having a voice service