A method for writing a pattern on an object by a charged particle beam comprises the steps of: dividing a pattern to be written on the object into a plurality of pattern blocks that cause a proximity effect with each other; determining a pattern density for each of said pattern blocks; selecting a specific pattern block as a reference pattern block; setting a dose level of exposure of the charged particle beam to a reference dose level such that the reference pattern block is exposed with a predetermined total dose level which includes the contribution of the exposure by the charged particle beam and the contribution of the exposure by the backscattered charged particles; exposing the plurality of pattern blocks including the reference pattern block by the charged particle beam with the reference dose level; and exposing those pattern blocks that have the pattern density smaller than the pattern density of the reference pattern block by a defocused charged particle beam with a total dose level set such that the total dose level for those pattern blocks is substantially identical with the total dose level of the reference pattern block.

The present invention generally relates to fabrication of semiconductor devices and more particularly to a process for writing a semiconductor pattern on an object such as a semiconductor substrate with a compensation for the proximity effect.
The electron beam lithography is a key process for fabricating advanced semiconductor integrated circuits having a very large integration density. With the use of the electron beam lithography, a device pattern having a line width of less than 0.05 .mu.m can be fabricated easily with an alignment error of less than 0.02 .mu.m. Thus, the electron beam lithography is expected to play a major role in the fabrication of future integrated circuits such as DRAMs having a storage capacity of 256 Mbits or more.
In the fabrication of memory devices, the throughput of production is an essential factor, in addition to the resolution of the device patterning. In this respect, the electron beam lithography that uses a single, focused electron beam for the exposure, is disadvantageous as compared with the conventional optical exposure process that exposes the entire device pattern in one single shot. On the other hand, such a conventional optical exposure process is reaching its limit of resolution, and there is a situation that one has to rely upon the electron beam exposure process for the fabrication of the large capacity memory devices of the future.
Under such circumstances, various efforts have been made for improving the throughput of the electron beam exposure process For example, the inventor of the present invention has previously proposed a so-called block exposure process wherein the device pattern is decomposed into a number of fundamental patterns and the electron beam is shaped in accordance with one of these fundamental patterns. With the use of the block exposure process, one can now achieve a throughput of about 1 cm.sup.2 /sec.
FIG. 1 shows the construction of a conventional electron beam exposure system that uses the technique of block exposure. Referring to the drawing, the electron beam exposure system is generally formed from an electron optical system 100 for producing and focusing an electron beam and a control system 200 for controlling the optical system 100.
The electron optical system 100 includes an electron gun 104 as a source of the electron beam. The electron gun 104 includes a cathode electrode 101, a grid electrode 102 and an anode electrode 103, and produces the electron beam generally in the direction of a predetermined optical axis O in the form of spreading beam.
The electron beam thus produced by the electron gun 104 is passed through a shaping aperture 105a formed in an aperture plate 105. The aperture plate 105 is provided such that the aperture 105a is in alignment with the optical axis O and shapes the incident electron beam to have a rectangular cross section.
The electron beam thus shaped is received by an electron lens 107a that has a focal point coincident to the aperture 105a. Thereby, the incident electron beam is converted to a parallel beam and enters into an electron lens 107b that focuses the electron beam on a block mask 110. It should be noted that the lens 107b projects the image of the rectangular aperture 105a on the block mask 110. As shown in FIG. 2, the block mask 110 carries a number of fundamental patterns 1a, 1b, 1c, . . . of the semiconductor device pattern to be written on the substrate in the form of apertures, and shapes the electron beam according to the shape of the aperture through which the electron beam has passed.
In order to deflect the electron beam passed through the electron lens 107b and address the desired aperture, deflectors 111, 112, 113 and 114 are provided, wherein the deflector 111 deflects the electron beam away from the optical axis O in response to a control signal SM1. The deflector 112 in turn deflects back the electron beam generally in parallel to the optical axis O in response to a control signal SM2. After passing through the block mask 110, the deflector 113 deflects the electron beam toward the optical axis O in response to a control signal SM3, and the deflector 114 deflects the electron beam such that the electron beam travels coincident to the optical axis O in response to a control signal SM4. Further, the block mask 110 itself is provided movable in the direction perpendicular to the optical axis O for enabling the addressing of the apertures on the entire surface of the block mask 110 by the electron beam.
The electron beam thus passed through the block mask 110 is then focused at a point f1 that is located on the optical axis O after passing through electron lenses 108 and 116. There, the image of the addressed aperture on the block mask 110 is demagnified at the point f1. The electron beam thus focused is then passed through a blanking aperture 117a formed in a blanking plate 117 and further focused on the surface of a substrate 123 that is held on a movable stage 126, after passing through electron lenses 119 and 120 that form another demagnifying optical system. There, the electron lens 120 serves for an objective lens and includes various coils such as correction coils 120 and 121 for focusing compensation and astigmatic compensation as well as deflection coils 124 and 125 for moving the focused electron beam over the surface of the substrate 123.
In order to control the exposure operation, the electron beam exposure system of FIG. 1 includes the control system 200, wherein the control system 200 includes memory devices such as a magnetic tape device 201 and magnetic disk devices 202, 203 that are provided to store various data of the device pattern of the semiconductor device to be written. In the illustrated example, the magnetic tape device 201 is used for storing various design parameters, the magnetic disk device 202 is used for storing the exposure pattern data, and the magnetic disk device 203 is used for storing the pattern of the apertures on the block mask 110.
The data stored in the memory devices is read out by a CPU 204 and transferred to an interface device 205 after data decompression. There, the data for specifying the pattern on the block mask 110 is extracted and stored in a data memory 206. The data stored in the data memory 206 is then transferred to a first control unit 207 that produces the foregoing control signals SM1-SM4 and supplies the same to the deflectors 111-114. Further, the control unit 207 produces and supplies a control signal to a mask moving mechanism 209 that moves the block mask 110 in the direction transverse to the optical path O. In response to the deflection of the optical beam by the deflectors 111-114 and further in response to the lateral movement of the block mask 110, one can address the desired aperture on the mask 110 by the electron beam.
The first control unit 207 further supplies a control signal to a blanking control unit 210 that in turn produces a blanking signal for shutting off the electron beam. This blanking signal is then converted to an analog signal SB in a D/A converter 211 and the analog signal SB is supplied to a deflector 115 that causes a deflection of the electron beam away from the optical axis O. In response to this, the electron beam misses the blanking aperture 117a and disappears from the surface of the substrate 123. Further, the control unit 207 produces a pattern correction data H.sub.ADJ and supplies the same to a D/A converter 208. The D/A converter 208 in turn produces a control signal S.sub.ADJ and supplies the same to a deflector 106 that is provided between the electron lens 107a and the electron lens 107b. Thereby, one can modify the shape of the electron beam that have passed through the addressed aperture in the mask 110. This function is used when the desired shape of the electron beam is different from the shape given by the apertures on the block mask 110.
The interface device 205 further extracts and supplies the data for controlling the movement of the electron beam on the surface of the substrate 123 to a second control unit 212. In response thereto, the control unit 212 produces a control signal for controlling the deflection of the electron beam on the surface of the substrate 123 and supplies the same to a wafer deflection control unit 215 that in turn produces and supplies deflection control signals to D/A converters 216 and 217. The D/A converters 216 and 217 in turn produce drive signals SW1 and SW2 for driving the deflectors respectively and supply the same to the deflectors 124 and 125 for causing the deflection of the electron beam. Thereby, the position of the stage 126 is detected by a laser interferometer 214 and the wafer deflection control unit 215 modifies the output deflection control signals and hence the drive signals SW1 and SW2 according to the result of measurement of the stage position by the laser interferometer. Further, the second control unit 212 produces a control signal that causes a lateral movement of the stage 126.
FIGS. 3(A) and 3(B) show the exposure of various patterns on the substrate 123 achieved by the apparatus of FIG. 1.
Referring to FIG. 3(A), the drawing shows the energy or dose of the electron beam supplied to an electron beam resist that covers the surface of the substrate for a case where the exposed device pattern designated as P.sub.1 has a pattern density .alpha. close to 100%. The pattern density herein means the percentage of the region of the substrate that is exposed by the electron beam. In FIG. 3(A), the threshold of exposure energy is represented as TH. When the dose of the electron beam exceeds the foregoing threshold TH, the exposure of the electron beam resist occurs. On the other hand, when the dose does not reach the threshold TH, no exposure is made.
In the exposure of FIG. 3(A), it should be noted that there is a substantial background exposure as represented by .beta., which is caused by the backscattering of electrons from the substrate. Such a background exposure is known as "proximity effect." When such a background exposure occurs, the dose of the electron beam for the device pattern P.sub.1 increases inevitably as indicated in FIG. 1(A). As a natural consequence, such a background exposure does not occur in small isolated patterns such as a pattern P.sub.2 where the backscattering of the electrons is small. Thereby, there occurs a difference in the dose of exposure between the region where a dense pattern is exposed and the region where a small isolated pattern is formed.
A similar change of dose occurs also between the device patterns having a large pattern density such as the pattern P.sub.1 and the device patterns having less dense pattern density such as a pattern P.sub.3 shown in FIG. 3(B). The device pattern P.sub.3 of FIG. 3(B) has a pattern density of 50%, for example, and there occurs a backscattering of the electrons with a magnitude represented as .alpha..beta..
Under such a situation, it will be understood that the variation of exposure, caused by the backscattering of electrons, has to be compensated for such that there is a uniform background exposure. Otherwise, there occurs a case where small isolated patterns such as the pattern P.sub.2 of FIG. 3(A) are not exposed.
In order to achieve the desired compensation for the background exposure, a so-called ghost exposure process is proposed by Owen et al. (Owen, G., Rissman, P. and Long, M. F., Application of the Ghost proximity effect correction scheme to round beam and shaped beam electron lithography systems, J. Va. Sci. Technol. B3(1), January/February 1985), which is incorporated herein as reference.
FIGS. 4(A)-4(C) show the principle of the foregoing ghost exposure process, wherein FIG. 4(A) shows the exposure corresponding to FIGS. 3(A) and 3(B) where there is no compensation of the proximity effect. There, it will be noted that the dose or level of exposure changes in the patterns P.sub.1, P.sub.2 and P.sub.3 because of the different level of backscattering and hence the background exposure. Further, it should be noted that there occurs a change in the level of dose even in the same device pattern between the region located at the center of the pattern and the region located at the margin of the pattern. In other words, there appears a shoulder at the marginal part of the exposed device pattern.
In order to compensate for the non-uniform background exposure, the ghost exposure process uses a diffused or defocused electron beam that is produced in correspondence to the inversion of the exposed device patterns as shown in FIG. 4(B). By superposing the ghost exposure of FIG. 4(B) on the exposure of the real pattern of FIG. 4(A), one can obtain a uniform background level throughout the patterns P.sub.1, P.sub.2 and P.sub.3 as shown in FIG. 4(C). Thereby, the problem of undesirable variation of the dose is successfully eliminated.
In the exposure process of FIG. 4(C), however, there exists an obvious disadvantage in that the ghost exposure has to be conducted for the entire surface of the substrate, regardless of the fact that there is a device pattern or not. Thereby, the efficiency of exposure is substantially reduced.
In the exposure process of FIG. 4(C), there exists another, more serious problem in that the fine device patterns such as the pattern P.sub.3 tend to be exposed excessively because of the increased background level. More specifically, the ghost exposure of FIG. 4(B) inevitably sets the background level of exposure of the device pattern P.sub.3 substantially identical with the background level of the device pattern P.sub.1 that fills or occupies an area of the substrate continuously with the pattern density .alpha. of about 100%. In FIG. 4, it should be noted that the threshold dose of the electron beam resist is represented by the broken line designated as TH. When the fine device pattern such as the pattern P.sub.3 is subjected to the excessive exposure, there arises a problem in that the size of the individual spot or line that forms the pattern P.sub.3 tends to be enlarged. Thereby, the proper exposure of fine or minute device patterns, which are essential for the fabrication of large storage memory devices, is no longer possible.
FIG. 5 shows the foregoing problem of increase of size of the exposed device pattern caused by the excessive dose of the exposure. For the sake of illustration, FIG. 5 is exaggerated significantly.
Referring to FIG. 5, the size of the exposed pattern such as a dot or line changes in relation to the dose of exposure and the threshold level of the electron beam resist. In the case where the level of dose is close to the threshold of exposure as represented by TH.sub.1, one obtains a pattern size D.sub.2 that is close to the desired device pattern D.sub.1. On the other hand, when the level of dose exceeds the threshold of exposure substantially as represented by TH.sub.2, one obtains a much larger pattern size D.sub.3. Thus, the exposure of the device patterns such as the pattern P.sub.3 by the ghost exposure inevitably decreases the resolution of the exposed pattern. In the worst case, the desired device pattern cannot be exposed.
One may think that such a problem of ghost exposure would be avoided by simply increasing the dose for those parts of the device pattern wherein the dose is insufficient such as the marginal part of the device. FIGS. 6(A)-6(D) show an example of the compensation for the insufficient dose according to the above mentioned principle, wherein FIG. 6(A) shows the device pattern to be exposed and FIG. 6(B) shows the corresponding background exposure level caused by the proximity effect. As a result of the reduced backscattering of electrons at the marginal part, the device pattern of FIG. 6(A) takes a form shown in FIG. 6(C) wherein the size of the individual pattern elements forming the device pattern of FIG. 6(A) is reduced at the marginal part. More specifically, it will be noted that the elongated rectangular pattern element forming the device pattern of FIG. 6(A) is deformed into a trapezoidal shape because of the reduced dose at the outer edge part of the device pattern. Thus, even when the dose of the exposure is increased in correspondence to the marginal part for compensating for the reduced dose in these parts, the trapezoidal shape of the Pattern element is not rectified. See FIG. 6(D) that shows the device pattern exposed on the substrate with such a compensation process. In order to obtain a correct rectangular shape of the exposed pattern element, one has to divide the pattern element into a plurality of subelements and change the dose in correspondence to each subelement as shown in FIG. 6(D) by the asterisk, solid circle and the solid square However, such a subdivision of the pattern element is contradictory to the improvement of throughput of exposure achieved by the block exposure process.

Electron beam exposure process for writing a pattern on an object by an electron beam with a compensation of the proximity effect


This is an insulation-type power factor correction circuit including a resonance unit configured to accumulate energy of a surge occurring when the first switching element is turned off and to transmit a resonance current generated by resonating the first capacitor and the primary winding of the second transformer from the primary winding of the second transformer to the secondary winding, a rectifier unit configured to rectify a resonance current output from the resonance unit, a smoothing unit configured to regenerate power output from the rectifier unit to an output of the insulation-type power factor correction circuit, and a control unit configured to control a first switching element for each cycle.

It is known that power factor correction (PFC) circuits are used as, for example, active filters for reducing harmonic distortion caused in a DC input/DC output power supply (DC-DC conversion circuit). However, because PFC circuits are not insulated from AC lines, there is a possibility that fatal accidents will occur, such as for example electrification, which may be caused when a human body touches electric currents between the output voltage of a PFC circuit and the ground, or such as electrical leakage between devices. Accordingly, DC-DC conversion circuits of an insulation type have conventionally been provided in a stage later than PFC circuits. However, DC-DC conversion circuits of an insulation type use transformers for transmitting electric power, resulting in a low efficiency (input power/output power) and complexity in circuit configurations.
Accordingly, it is desired that PFC circuits be insulated. However, because a transformer is used for insulation, a high surge voltage is caused by the leakage inductance of the transformer when the field effect transistor (FET) connected to the primary side of the transformer is turned off. Also, a high-voltage FET that can withstand the surge voltage has to be used, leading to a higher cost for FETs. Also, a high-voltage FET suffers from strong ON-resistance, which causes more losses and a reduction in the efficiency. Also, when a snubber circuit is used on the primary side of a transformer so as to suppress a surge voltage, resistors in the snubber circuit cause power losses, reducing the efficiency in DC-DC conversion circuits of an insulation type.
For example, a switching power supply device that reduces noise and switching losses caused by soft switching and that also regenerates, when a switching element is turned on, energy accumulated in a charge accumulation capacitor when the switching element is turned off is known. According to this switching power supply device, when a switching element is turned on, an auxiliary switching element is turned on first. Next, the auxiliary switching element is turned on during a period of one fourth of the resonance period between the capacitance of the charge accumulation capacitor and the inductance of the primary winding of the charge regeneration transformer so as to transmit the energy accumulated in the charge accumulation capacitor to the transformer. When the auxiliary switching element is turned off, the energy accumulated in the charge regeneration transformer flows into the DC input power supply via the charge regeneration diode. As a result of this, the entirety of the losses is reduced and higher frequencies are realized.
Also, for example, a transformer insulation DC-DC converter that includes a diode, a resonation capacitor, primary winding and an auxiliary capacitor of an auxiliary transformer, and secondary winding and a diode of an auxiliary transformer is known. The diode has its one terminal connected to the connection point between the first winding of the transformer and the transistor. The resonation capacitor is connected between the other terminal of the diode and the cathode terminal of the DC power supply. The primary winding and auxiliary transistor of the auxiliary transformer are connected in series between the anode terminal and the cathode terminal of the DC power supply. When the auxiliary transistor is turned on or turned off simultaneously with the transistor, and when the auxiliary transistor is turned on, the discharge energy of the resonance capacitor is regenerated to the DC power supply through the auxiliary transformer and the diode. As a result of this, the switching losses and noise in the transformer insulation DC-DC converter are reduced and the efficiency is improved.
Patent Document 1: Japanese Laid-open Patent Publication No. 11-178341
Patent Document 2: Japanese Laid-open Patent Publication No. 11-318075

Insulation-type power factor correction circuit


A method of making a molybdenum or molybdenum alloy metal strip is disclosed. The method includes roll compacting a molybdenum-based powder into a green strip. The method also includes sintering the green strip followed by a combination of warm rolling, annealing, and cold rolling steps to form the final metal strip which may be cut-to-length. The strip at the final thickness may also undergo an optional stress relief step.

The conventional method of producing strip or sheets of molybdenum from a metal powder includes first making a slab. This is achieved by a compaction process, such as Cold-Isostatic Pressing, Vacuum Hot Pressing, or Die Pressing. The resulting thick slabs of molybdenum about 1.0″ to 4.0″ thick are then sintered at temperatures in the 1400° C. to 2300° C. range and then hot rolled at 1100° C. to 1400° C. range into plates about 0.4″ to 0.6″ thick. The plates are then annealed above the recrystallization temperature of the material and hot rolled again into sheets at slightly lower temperatures (1000° C. to 1250° C.) to a thickness close to 0.050″. Multiple intermediate chemical etching and cleaning steps are carried out to remove embedded iron particles and surface oxides from the previous hot rolling operations. Subsequent rolling is carried out at warm working temperatures in the 200° C. to 500° C. range (lower temperatures are used as the material is progressively worked to thinner gauge). After approximately 50% reduction at the warm working temperatures, the material can be cold worked at room temperature with intermediate stress relief anneals.
Therefore, the conventional process for making the molybdenum-based thin strips from metal powders requires several hot rolling, chemical etching, and cleaning operations. Such an energy intensive process which also requires the use of harmful chemicals is costly, potentially hazardous, and environmentally unfriendly. Thus, there is a need for improved processes for manufacturing molybdenum-containing sheet.

Process for making molybdenum or molybdenum-containing strip


Systems and methods for displaying customized product information on a user device. A server may receive sensor data from one or more tracking sensors of a mobile device of a user, wherein the sensor data contains sensor measurements made continuously by the one or more tracking sensors and generate a behavioral pattern data records based upon the sensor data. The server may calculate a likelihood score associated with a product based on the behavioral pattern data records and identify a phase associated with the user and the product. The server may then cause to display customized electronic content for a product on a user interface of the mobile device based on the likelihood score and the identified phase.

People consume an ever increasing amount of text and other media daily in different environments and various modes including mobile devices such as mobile phones and tablets. The popularity of mobile devices has had some unintended and dangerous consequences when mobile devices are used to consume content by a user that is operating a vehicle. Distracted driving, the term used for driving while engaged in other activities such as texting, talking on the phone, watching media, using a navigation system, reading content is estimated to increase the risk of getting into a crash by as much as three times. As such, numerous efforts have been undertaken to reduce distracted driving and improve highway safety, like adopting laws banning cell phone use while operating a vehicle, employing the use of hands-free aids and using software or connecting devices to vehicle onboard diagnostics to prevent device use while a vehicle is in motion.
Though these and other efforts have attempted to reduce instances of distracted driving, many people, especially young drivers, still continue to engage in distracted driving behaviors. Additionally, some of these techniques are problematic because the voice recognition software used in a hands-free aid may not be very good, resulting in greater distraction of the user when the device doesn't recognize a command or executes an improper command. Additionally when software or onboard diagnostics are used to shut off a device completely, a user is prevented from using aids in the mobile device such as GPS or playing podcasts, audio, music and the like through a mobile device. As such, there is a continuing need to develop techniques to control displayed content on mobile devices, especially when mobile devices are used while operating a vehicle.
Furthermore, conventional user behavior analysis has several technical shortcomings. User behavior analysis is subjective and conjectural, where an observer based upon a limited observation makes a subjective judgement as to the behavioral pattern of the user. Such subjective judgment is inaccurate to be a basis of presenting content or products to the user. Furthermore, the manual observation is cumbersome and inefficient as it may require a human observer to deduce and analyze behavior patterns of a few users.

Systems and methods for presenting content based on user behavior


A seal for sealing between a trunnion and bearing cup of a joint member includes a main annular body. A plurality of annular lips extend radially inwardly from the main body. The lips are configured for engaging an outer bearing surface of the trunnion. A first one and a second one of the lips slope in a first direction with respect to the outer bearing surface of the trunnion and a third one of the lips slope in a second direction with respect to the outer bearing surface of the trunnion.

Joint assemblies such as universal joints are common components in automotive vehicles for applications requiring a transmission of torque. Joint assemblies typically include a body portion with a plurality of trunnions extending radially outwardly therefrom. A hollow cylindrical bearing cup is rotatably disposed about the distal ends of each of the trunnions. Roller bearings are disposed within the bearing cup and permit the rotation of the bearing cup about the trunnions. The trunnions may have central bores wherein a fluid such as a lubricant is disposed during assembly to lubricate the roller bearings during operation.
As is known, a seal is typically positioned between the outer surface of the trunnion and an inner surface of the bearing cup to form a seal therebetween. To provide an effective seal, the seal must prevent contaminants from entering into the bearing cups and restrict a flow of the fluid out of the area of the bearing cup where the roller bearings are located. A lip seal is typically employed to accomplish effective sealing.
The lip seal includes a plurality of lips that extend radially inwardly towards the outer surface of the trunnion in a direction away from the roller bearings. The geometry of the seal militates against entry of contaminants to the bearing cup. Another advantage of the geometry of the seal is the contact pressure of the lips against the trunnions is relieved as pressure builds up within the joint during high temperature operations. The relief of the pressure allows trace amounts of fluid to flow under the lips of the seal, thereby improving the lubrication of the lips and minimizing wear to the seal. However, it has been found that universal joints exposed to very high underbody temperatures may allow too much fluid to flow under the lips, resulting in a visible fluid trail that may be undesirable.
An example of a joint assembly and seal is shown and described in U.S. Pat. No. 5,716,277, the disclosure of which is hereby incorporated herein by reference in its entirety. The seal in U.S. Pat. No. 5,716,277 includes an inner lip extending towards the roller bearing and two additional lips extending away from the roller bearings. The geometry and arrangement of the lips effectively prevents fluid loss past the inner lip, but creates potential for accelerated wear on all three seal lips because outward flow of the fluid for lubrication of the outer seal lips is limited by the innermost lip (i.e. the lip closest to the roller bearings).
It is desired to include a seal for a universal joint that maintains a flow of a fluid to a desired one of the lips of the seal, minimizes wear, and effectively militates against fluid loss during high temperature operations.

Cardan universal joint seal with radially extending lips

NEAPCO INTELLECTUAL PROPERTY HOLDINGS, LLC


In certain aspects, the present invention provides miniature proteins resulted from a protein scaffold such as an avian pancreatic polypeptide that can be modified by substitution of at least one amino acid residue. In other aspects, the present invention provides diagnostic and therapeutic uses of these miniature proteins.

Biological interactions, such as protein:protein interactions, protein:nucleic acid interactions, and protein:ligand interactions are involved in a wide variety of processes occurring in living cells. For example, agonism and antagonism of receptors by specific ligands may effect a variety of biological processes such as gene expression, cellular differentiation and growth, enzyme activity, metabolite flow and metabolite partitioning between cellular compartments. Undesirable or inappropriate gene expression and/or cellular differentiation, cellular growth and metabolism may be attributable, at least in many cases, to biological interactions involving the binding and/or activity of proteinaceous molecules, such as transcription factors, peptide hormones, receptor molecules, and enzymes.
Peptides present potential therapeutic and prophylactic agents for many human and animal diseases, biochemical disorders and adverse drug effects, because they can interact highly specifically with other molecules. Thus, mimetic peptides have been designed and developed based on three dimensional protein structures. For example, many proteins recognize nucleic acids, other proteins or macromolecular assemblies using a partially exposed alpha helix. Within the context of a native protein fold, such alpha helices are usually stabilized by extensive tertiary interactions with residues that may be distant in primary sequence from both the alpha helix and from each other. With notable exceptions (Armstrong et al., 1993, J. Mol. Biol., 230: 284-291), removal of these tertiary interactions destabilizes the alpha helix and results in molecules that neither fold nor function in macromolecular recognition (Zondlo et al., 1999, J. Am. Chem. Soc., 121: 6938-6939). The ability to recapitulate or perhaps even improve on the recognition properties of an alpha helix within the context of a small molecule may find utility in the design of synthetic mimetics or inhibitors of protein function (Cunningham et al., 1997, Curr. Opin. Struct. Biol., 7:457-462) or new tools for proteomics research.
Proteins generally recognize each other using large and shallow complementary surfaces. Therefore, small proteins (miniature proteins) with well-defined three-dimensional structures and finely tuned functional properties are perhaps ideally suited for protein surface recognition and disruption of protein:protein interaction. Clearly, there is a need for developing the miniature proteins (in particular, those with high affinity and high specificity for a target molecule) as therapeutics and prophylactics.

Protein binding miniature proteins and uses thereof


The feed reflected Doherty amplifier utilizes the output characteristics of the carrier amplifier to control the input signal of the peaking amplifier to improve the gain, linearity and efficiency of a Doherty amplifier. The feed reflected Doherty amplifier comprises an input power splitter, a carrier amplifier branch and a peaking amplifier branch combined into a common load, an output directional coupler and an input directional coupler connected via a phase shift element.

Modern wireless communications systems including spectrum efficient modulation schemas such as Wideband Code Division Multiple Access (WCDMA), Orthogonal Frequency Division Multiplexing (OFDM) have high peak to average ratio signals. The typical peak to average ratio of the signals in 3G and 4G Long Term Evolution (LTE) systems ranges from 6 dB to 12 dB.
The RF power amplifiers used in wireless communication systems are required to have higher efficiency and linearity to handle such a high peak to average ratio signal. As generally there is a trade-off between the efficiency and linearity. RF power amplifiers achieve the highest efficiency and the worst linearity at the saturation level. At low power level which is also called back-off level, the linearity becomes better while the efficiency decreases. In order to increase the efficiency at back-off level, the load of the amplifier can be changed dynamically according to the level of the input signal, which defined as load modulation. Some well-known examples of load modulation techniques are those used in the Doherty amplifiers and the Chireix-outphasing amplifiers.
The Doherty amplifier, which was first proposed by W. H. Doherty in 1936, is widely used in modern wireless communication systems as it provides higher efficiency over an extended output power range. FIG. 1 illustrates the structure of the conventional Doherty amplifier comprising carrier and peaking amplifier branches combined into a common load. The carrier amplifier is also defined as the main amplifier and biased at Class AB or B, and the peaking amplifier is also defined as the auxiliary amplifier and biased at Class C. The load at the combining node is Z0/2 where Z0 is the matched impedance of the carrier and peaking amplifiers for maximum power and efficiency.
The applied input signal is split by an input power divider. The carrier amplifier is fed directly from the input power divider; whereas the peaking amplifier is connected via the input offset line. The input offset line length is adjusted for phase compensation with the carrier amplifier. The outputs of the carrier and peaking amplifiers are combined into the load via the output offset lines and an impedance inverting network. At the low power levels below a threshold point, only the carrier amplifier is in operation and the peaking amplifier is non-conductive and presents high impedance in ideal conditions. But in practice, with the effect of the package parasitics and matching elements the non-conductive output impedance of the peaking amplifier shifts. Therefore an output offset line is line required in order to have high impedance at the combining node when the peaking amplifier is non-conductive. The output offset line of the carrier amplifier has the same length as the peaking output offset line for phase coherence. The impedance inverting network is configured using a quarter-wavelength line with a characteristic impedance of Z0. For low power levels below the threshold point, the impedance inverting network converts the load impedance Z0/2 to 2Z0. When presented with 2Z0 load impedance, the carrier amplifier reaches saturation at a power level lower than the rated peak power. This threshold level where the first peak efficiency point is achieved is defined as 6 dB back-off level for a 2-way symmetrical Doherty amplifier.
As the power level increases above the threshold point, the peaking amplifier starts to conduct and the supplied current from the peaking amplifier modulates the load seen by the main amplifier. The current driven by the peaking amplifier increases the voltage on the load, and the impedance seen by the main amplifier gets decreased via the impedance inverting network. As the input signal is increased further both amplifiers will be presented with Z0 and maximum combined power with maximum efficiency is obtained.
Doherty amplifiers are expected to exhibit higher efficiency over an extended output power range without any degradation in gain and linearity characteristics with respect to the same periphery class AB amplifier. In practice, conventional Doherty amplifiers utilizing Si LDMOS or GaN devices achieve lower gain and linearity than the same periphery class AB amplifiers. Biasing the peaking amplifier at class C decreases the total gain of the conventional Doherty amplifier. For the same input voltage level, the output current level of a class C biased amplifier is lower than the same amplifier biased as class B or AB. As the carrier amplifier is allowed to reach saturation at the threshold point which is at least 6 dB below the maximum output power level, the non-linearity produced by the conventional Doherty amplifier is higher than the class AB amplifier with the same periphery. Furthermore, the peaking amplifier operating at class C causes additional non-linearity to the conventional Doherty amplifier characteristics. Nevertheless, for an ideal Doherty amplifier, the carrier amplifier gain compression characteristics and the peaking amplifier gain expansion characteristics can be regarded as correspondingly matched to produce a combined linear behavior. However, considering the trans-conductance (gm) characteristics of the transistors based on the bias and input voltage level and the output-conductance characteristics of the transistors based on the load-line, it is not easy to obtain a matched gain compression and expansion curves for the carrier and peaking amplifiers.
Without concerning the linearity issue and focusing on the efficiency enhancement of the Doherty amplifier, the peaking amplifier is desired to conduct above the threshold point where the carrier amplifier reaches saturation. So, the input power division ratio, the bias points of the carrier and peaking amplifiers must be strictly configured to achieve higher efficiency over an extended output power range.
A common technique to improve the efficiency, gain and linearity properties of the Doherty amplifiers is known as "Bias-adapted Doherty amplifier". FIG. 2 illustrates the block diagram of the bias-adapted Doherty amplifier. This technique utilizes analog or digital circuits to control the input power and/or the bias level of the peaking amplifier according to the input signal level. Control circuits first detect the envelope of the input signal level and change the input power and/or the bias point of the peaking amplifier above a predetermined threshold point. Bias adaptation schemes require extra analog, digital circuit periphery and especially for wide instantaneous bandwidth applications, the delay and the speed of the control circuits become more critical in terms of extra additional power dissipation. The main drawback of this technique is the challenge of shaping the peaking amplifier behavior without using any feedback from the carrier amplifier.
The conventional feed-forward linearization technique utilizes the output characteristics of the main amplifier and provides a high level of linearization while disregarding any concern for efficiency. FIG. 3 illustrates the schematic diagram of the feed-forward amplifier. There are 2 loops; first is the cancellation loop and second is the correction loop. In the cancellation loop, the forward output signal of the main amplifier is sampled by a coupler and subtracted from the input signal to obtain only the non-linear products of the main amplifier. In the correction loop, these non-linear products are amplified by an error amplifier and combined with the main amplifier output by an output coupler. Although this technique provides a good linearization, because of the DC power wasted by the error amplifier and the lack of any efficiency enhancement schema such as load modulation, feed-forward amplifiers provide a low level of efficiency and are not widely preferred in modern wireless communication systems.

Feed reflected Doherty amplifier and method for driving Doherty amplifiers

Aselsan Elektronik Sanayi ve Ticaret Anonim Sirketi


Disclosed is a system and that synchronizes utilization of a data transfer with an audio/video stream. Time information contained within an audio/video stream is monitored for a specified time at which a data transfer may be combined with the audio/video stream. Combination includes logical operations, arithmetic operations, and may include screen windowing or other operations. Time required to request and receive a data transfer may be monitored or estimated such that requests for data are issued in advance of utilization of the data, allowing for data transfer time and network access time or other factors. Requests for a data transfer may be processed employing user information such that returned data transfers reflect a characteristic of the user.

a. Field of the Invention
The present invention pertains generally to digital data transferred over a network in conjunction with video or audio data and more specifically to synchronization of data transferred over a network with video or audio data transferred on that network or on an independent network or channel.
b. Description of the Background
Television and audio broadcast may employ a range of broadband media including cable, satellite and high speed Internet. The term broadband refers to the capability of the media or network to carry multiple channels at one time. Video and audio programs are typically allocated a constant bandwidth such that dropouts or distorted output is not produced. A channel that provides a constant minimum bandwidth rate may be referred to as isochronous or as a constant bit rate (CBR) channel. Other services that transfer data on the network, such as Internet, have typically been asynchronous, wherein bandwidth may vary depending on network load. New standards are emerging that provide for isochronous transfer of data on a network. Such standards include voice over DSL (Digital Subscriber Line) and DOCSIS (Data Over Cable System Interface Specification) and more specifically by PacketCable that provides a method for isochronous data transfers over cable.
The advent of isochronous data transfer over broadband networks enables streaming audio and video programs other than those provided by a cable or television operator. Additionally, isochronous data transfers allow the possibility for data from one channel to be synchronized with an audio/video broadcast stream or with data from another channel. Synchronized data transfer may be employed to provide modification and enhancement of a broadcast program. For example, subtitles in a number of spoken languages, or sign language, may be added to televised programs. Such additions are outside the capabilities of captioning facilities of televisions. Additionally, synchronized data transfers may be used to add local content to advertising, such as local automobile dealer information presented in conjunction with a national automobile advertisement. Data transfers must be synchronized in some manner such that subtitles appear at the correct time or advertising message enhancements appear at the correct time. Synchronized data transfers utilized in conjunction with an audio/video stream may provide increased viewer enjoyment and may provide additional opportunities for revenue. As such, a new method is needed to control the transfer of data and the utilization of that data in synchrony with an audio/video stream or data from another channel.

Synchronizing services across open cable and packet cable


The present disclosure provides an open-air circulating pool for simulating ecological damage, and belongs to the technical field of simulation tests of ecological environment impact. The open-air circulating pool is provided with a set of devices for simulating natural ecological environments of different water quality and sediments, as well as changes in water bodies caused by a sea occupation project, discharge of a typical pollution source and a sudden leakage accident, so as to observe changing trends of an aquatic organism and an environmental element, and qualitatively and quantitatively determine a law of causality of damage. The set of devices includes an open-air wave-flow circulating pool, an additive injection apparatus and an ecological indicator sampling and detection apparatus.

In recent years, the ecological construction and ecological damage assessment and restoration in waterway transportation have attracted much attention. In order to scientifically identify the causality between the typical ecological damage source term and the ecological damage during the construction and operation of waterway transportation, it is necessary to test the ecological damage pathways, processes and interactions in a simulated environment. This will provide technical support for the in-depth understanding, prevention and mitigation of the ecological damage, as well as guidance on environmental planning, engineering construction, protection zone selection and environmental protection engineering design, etc.
At present, there is lack of an open-air circulating pool simulation system for ecological damage. The existing oil spill weathering simulation pools and test devices include: Wu Haitao et al., MARINE OIL SPILL WEATHERING SIMULATION SYSTEM, China, CN101551321B, 2011-12-28; Qiao Bing et al., TEST SYSTEM AND METHOD FOR SIMULATING IMPACT OF OIL SPILL WEATHERING ON WATER QUALITY, China, CN105181919B [P], 2018-01-19; Wu Xuan et al., WAVE TANK TEST DEVICE FOR OIL SPILL DISPERSANT, China, CN206891688U[P], 2018-01-16. They mainly simulate the weathering condition of the oil spill, the impact on water quality, and the cleanup effect, and never involve ecological impact simulation.

Open-air circulating pool for simulating ecological damage

China Waterborne Transport Research Institute


A power transmission includes an input shaft, an output shaft, and a plurality of gear ratios selectably engagable with the input shaft and the output shaft to transfer rotational energy from the input shaft to the output shaft to drive the output shaft at a selected output shaft speed. A plurality of clutches, each clutch is located at a clutch lay shaft of a plurality of clutch lay shafts and is configured to control selective engagement of only one gear ratio of the plurality of gear ratios.

Exemplary embodiments of the present disclosure pertain to the art of gas turbine engines, and more particularly to mechanical power extraction from a gas turbine engine.
Gas turbine engines are utilized to power aircraft, providing thrust to propel the aircraft. Further, mechanical energy is often extracted from the gas turbine engine to provide electrical power to various aircraft components and systems through a generator, at which rotational energy extracted from the gas turbine engine is used to generate electrical power.
Most modern gas turbine engines have multiple spools, e.g. a low pressure spool and a high pressure spool. Traditionally, the high pressure spool is used to drive the various aircraft components and systems via the generator. Efficiency concerns led to a desire to move power extraction from the high pressure spool to the low pressure spool. The low pressure spool, however, is typically not used for power extraction do to the larger range of operating speeds of the lower pressure spool, compared to a the range of operating speeds of the high pressure spool.

Transmission for low spool of gas turbine engine


A mobile communications system, designed to enable the overall amount of power emitted to be kept down, provided with a mobile station location information generating unit for generating location information indicating a present location of a mobile station when transmitting a request for increasing the transmission power from the mobile station in the middle of handover with base transceiver stations, a base transceiver station location information generating unit for generating location information indicating a present location of the base transceiver stations, a base transceiver station specifying unit for specifying one base transceiver station nearest to the mobile station from said location information, and a transmission power control unit for instructing an increase of the transmission power in only the specified base transceiver station.

1. Field of the Invention
The present invention relates to a method for controlling transmission power when transmitting a radio signal from a base transceiver station to a mobile station in a mobile communications system, for example, a CDMA mobile communications system, where a mobile station (MS) is able to receive and combine signals from a plurality of base transceiver stations (BTS). In particular, it relates to a method for controlling transmission power in the middle of handover.
2. Description of the Related Art
In the above CDMA mobile communications system etc., since the same frequency bandwidth is shared by a plurality of communicating parties, the signal of one communicating party becomes an interference signal for the signal of another communicating party, so it is desirable to keep the transmission power of the radio signals used by communicating parties as low as possible.
Further, when a mobile station near to a base transceiver station and a mobile station far from the base transceiver station simultaneously communicate with the base transceiver station, if the transmission power of the uplink signals from the mobile stations are the same, the base transceiver station receives the uplink transmission signal from the near mobile station at a high power level, while receives the uplink transmission signal from the far mobile station at a low power level. Therefore, the signal from the far mobile station receives strong interference due to the signal from the near mobile station and the quality of the signal from the far mobile station received by the base transceiver station degrades to a large extent, that is, a "far/near problem" occurs. As a technique for solving this far/near problem, methods for controlling the transmission power have been studied.
Looking at the control of for example the downlink transmission power during a soft handover in a CDMA mobile communications system, if a mobile station receives signals from a first base transceiver station and second base transceiver station communicating with it, the received signals are despread, then combined and the quality of reception after combination is measured by the mobile station. For example, the ratio of the level of reception of the interference wave with respect to the level of reception of the desired wave, that is, the SIR, is measured by the mobile station and the measured SIR is compared with the target SIR. When the result of the comparison is that the measured SIR is determined to be larger than the target SIR, the mobile station sends transmission power control information instructing a reduction of the transmission power of the transmitted signal from the base transceiver station to the mobile station, while conversely when the result is that the measured SIR is judged to be smaller than the target SIR, it sends transmission power control information instructing an increase of the transmission power of the transmitted signal from the base transceiver station to the mobile station. The first and second base transceiver stations raise and lower the transmission power to the mobile station based on the transmission power control information received from the mobile station. In this way, the transmission power is controlled so that the SIR measured by the mobile station becomes constant regardless of the present location of the mobile station.
Summarizing the problem to be solved by the invention, in the control of the downlink transmission power during a soft handover by each base transceiver station, when a mobile station is temporarily hidden in the shadow of a building etc., the level of reception of the mobile station falls. Therefore, the mobile station sends transmission power control information instructing an increase of the transmission power to the base transceiver station in the middle of soft handover. The base transceiver stations work to improve the quality of the received signal at the mobile station by raising the transmission power in accordance with the transmission power control information received from the mobile station.
During soft handover, however, since one mobile station is communicating with a plurality of base transceiver stations, if information requesting an increase of transmission power is sent from the mobile station, the transmission powers from all of the plurality of base transceiver stations end up rising simultaneously by exactly the same amount. Therefore, an increase in the overall amount of power emitted in the CDMA mobile communications system is caused. Along with this, a reduction in the subscriber capacity is caused. Still further, interference with other mobile stations in the middle of communication around that mobile station is caused.

Mobile communications system and method for controlling transmission power


A centrifuge apparatus is used for collecting white blood cells (WBC), primarily mononuclear cells, from whole blood stratified into layers. A thin mononuclear (MNC) layer is formed at the interface of red blood cells and plasma. A barrier is positioned in the separation vessel of the centrifuge at a location to intercept the thin layer. MNC fluid is allowed to pool behind the barrier before collection is started. To collect the MNC pool, the stratified red blood cell layer is raised from below the interface level by slowing or reversing flow in the RBC exit line thereby causing the MNC pool to spill over the barrier into a well in which a collect line is positioned. Collection ceases when a desired percentage of the pool is removed and the normal position of the interface is re-established; thereafter the pool builds again. By raising the MNC pool from below, improvements in purity and collect volume are achieved. The collection procedure can be useful for harvesting granulocytes and, in general, any sparse stratified component of a centrifuged solution where the sparse component is layered between more dense and less dense strata.

Centrifugation is a technique used to process whole blood in order to separate the blood into its various components. To reduce personal contact with blood products and reduce cross-contamination between different blood sources, the centrifugal apparatus can be fitted with a disposable plastic vessel through which the blood is circulated. The vessel is fitted into a centrifuge fixture that is driven by a motor. An exemplary vessel is a circumferential separation channel having several outlets positioned at different radial positions within the channel in order to remove blood components which have been separated by the centrifuge into stratified layers of differing density. Red blood cells (RBC) being the most dense of the components are stratified within the channel at the most radially outward location whereas the stratified layer of plasma is the least dense component and therefore the most radially inward layer. A relatively thin layer called the buffy coat contains white blood cells and platelets and is located between the red blood cell layer and the plasma layer. Within the buffy coat the platelets are stratified toward the plasma while the white blood cells are stratified toward the red blood cells. Depending on centrifuge speed, platelets may also be dispersed within the plasma.
The disposable plastic vessel which is fitted into a rotating fixture within the centrifuge is connected to the blood source and to collection reservoirs through a disposable tubing set. In that manner, the centrifuge equipment itself is kept out of contact with blood and the disposable tubing set and separation channel are discarded after one procedure. The source of blood can be whole blood flowing directly from a donor or patient, or it can be previously donated bone marrow or blood.
Blood components may be collected from a patient, stored and perhaps frozen, and reinfused into the patient days or even years later. The mononuclear cell portion of white blood cells is sometimes collected, stored in the above manner, and reinfused into the patient for the treatment of diseases such as cancer. There are obvious advantages to returning blood components from the patient's own blood rather than using the blood of a donor. It is generally agreed that the safest blood a person can receive is his or her own blood (autologous blood). The use of autologous blood reduces the risk of exposure to transfusion transmitted disease and febrile/allergic transfusion reactions. To accomplish the collection of white blood cells (WBC), an apheresis system has been developed for harvesting them from the buffy coat. In particular, the mononuclear cell (MNC) portion of WBCs are harvested including lymphocytes, monocytes, progenitor cells, and stem cells. In this document the designations WBCs and MNCs are usually used interchangeably. Efficient equipment for collecting MNCs is described in U.S. Pat. No. 4,647,279. However, even with efficient equipment, the collection of mononuclear cells is difficult since they make up only a small fraction of the total blood volume. For a patient of normal size with a normal MNC count, the total volume of MNCs may be about 1.5 milliliters, that is about 0.03% of the total blood volume. As a consequence, when whole blood is centrifuged, only a very thin MNC layer appears between the red blood cell and plasma layers.
The thin MNC layer presents a challenge when attempting an MNC harvest. Because the MNC fraction of whole blood is so small, the equipment referred to above includes a barrier positioned in the channel upstream of the RBC exit port. MNCs are accumulated at the barrier with a WBC collection port placed in front of the barrier. The fraction collected through the WBC collection port is actually a mixture of WBCs, platelets, plasma and RBCs. In collection procedures, the color of the collected fraction may be monitored in order to adjust the blood inflow and plasma outflow rates, if necessary, manually or automatically, to fine tune the position of the MNC layer so that the MNC layer corresponds in position with the WBC collection port. Usually, an operator makes very fine adjustments to the speed of the plasma pump in order to position the MNC layer properly for collection. If manual monitoring is used, the operator judges the position of the MNC layer according to the color of the fluid leaving the collection channel, and adjustments are made to provide the desired color in the collect port. If, for example, the operator begins to observe a reddish tint, the presence of RBCs are signified in the collect line. In such case, there is a need to increase the amount of plasma in the separation channel so that the RBC layer can be lowered. That can be accomplished by reducing plasma pump speed. Fine control is provided over the speed of the plasma pump such that adjustments may be made in collect volume on the order of one tenth milliliter per minute. Even though small changes are possible in the speed of the pump, it is not unusual for a change in plasma pump speed to over or under-correct, necessitating further change in pump speed. As a consequence, the interface positioning system, manual or automatic, can be involved in a vibratory chasing of the correct interface position with the result of decreased efficiency and purity in collecting the MNC layer. A further problem is that after each change in pump speed the process requires a period of time for the change to take effect, that is, for the new interface position to become established. Attempts have been made to use optical monitoring equipment to judge the opacity of the collect volume and automatically adjust plasma pump speed. However, such techniques designed to automate the system are also subject to oscillations around the control point and generally provide little improvement over the system when it is operated manually. Basically, all of these problems result from the fact that the target species is sparse and forms a very thin stratified layer which is difficult to harvest separately from other components, and because of the relatively low response of the interface to changes in the flow rate.
Because of the difficulty in properly positioning and maintaining the interface, a relatively wide band of volume is collected from the WBC port so that there is an assurance that the thin white blood cell layer has been collected. By collecting a wider band, however, a considerable amount of plasma, platelets, or red blood cells are also collected together with the white blood cells. Such a technique is efficient in the sense that it collects most of the stratified white cells, but it is low in purity. Also, the volume of collection is increased over what is needed. The goals of high MNC yield or efficiency and a low collection volume of high purity are somewhat mutually exclusive since it is difficult to extract only the thin stratified layer of white blood cells. Generally, volume and purity are sacrificed in favor of collection efficiency.
To further explain and illustrate, WBCs are comprised of mononuclear cells and polymorphonuclear cells (PMNs including granulocytes). Granulocytes are normally a small sub-population of WBCs in healthy people but grow to a more significant sub-population when the body reacts to disease. When whole blood is centrifuged, depending on centrifuge speed, the thin buffy coat layer is itself stratified into a still thinner layer of MNCs and a thin layer of platelets. The granulocytes are found in the buffy coat tending more toward the RBC layer and are also found in significant populations within the RBC layer. When the needs of a patient make it advisable to harvest granulocytes, a drug is generally provided to the patient which enables the granulocytes to migrate from the RBC layer into the buffy coat as a thin layer between the RBCs and the MNCs. In harvesting granulocytes, it has been necessary to also collect MNCs since the layers are too thin to be harvested separately. A substantial volume of RBCs and plasma are also collected in the procedure.
It is an object of the current invention to provide an improved collection procedure for harvesting sparse layers of stratified components in centrifuged liquids such as mononuclear cells in blood in order to collect a decreased volume with higher purity at high efficiency.

Control system for the spillover collection of sparse components such as mononuclear cells in a centrifuge apparatus


A method of manufacturing a semiconductor device includes forming an interconnection layer patterned to predetermined shapes on a semiconductor base, forming a plasma TEOS film as a first insulating layer on the surface of the interconnection layer while reducing radio frequency (RF) power, and forming an ozone TEOS film as a second insulating layer on the first insulating layer.

1. Field of the Invention
This invention relates to a method of manufacturing a semiconductor device, and particularly to a method of forming interlayer insulators or inter-metal layers.
2. Description of the Related Art
A semiconductor device using two types of TEOS (tetra ethyl ortho silicate) layers or films as interlayer insulators has heretofore been known. This type of semiconductor device has been formed in accordance with a processing flow shown in FIG. 2, for example.
A metal material such as aluminum or the like is deposited on a semiconductor base 201 (this semiconductor base may be a semiconductor substrate itself or one including a semiconductor substrate and several films or layers formed on the semiconductor substrate). Thereafter, the metal material is patterned to predetermined configurations or shapes by photolithography to thereby form metal traces or interconnections 203. The width between the adjacent metal interconnections 203 is about 1.4 .mu.m.
A P-TEOS film (plasma TEOS film) 205 corresponding to a lower interlayer insulator is next formed to a thickness of about 2000 .ANG. by a CVD method using plasma excitation. A condition for forming the P-TEOS film is represented as shown in FIG. 3. Namely, RF power for exciting plasma is a predetermined value (400W in the present example) during a period from the beginning of formation of the P-TEOS film to the completion of its formation (for about 17 seconds).
An O.sub.3 TEOS (ozone TEOS film) 207 corresponding to an upper interlayer insulator is formed on the P-TEOS film 205 in about 8000 .ANG. by an atmospheric-pressure CVD method.
A condition for forming the O.sub.3 TEOS film 207 is represented as shown in FIG. 4.
However, in the above-described method, the shape of the interlayer insulator between the adjacent metal interconnections 203 becomes steep (large in steplike offset or difference in level and steep in gradient) as illustrated in an enlarged cross-sectional view of FIG. 5. As a result, the coverage of the upper metal interconnection formed on the interlayer insulator becomes worse. Further, since an unnecessary metal interconnection material is easy to remain at each steplike-offset portion (on the interlayer insulator located between the metal interconnections 203) upon the patterning process for forming the upper metal interconnection, its improvement has been desired.

Method of manufacturing a semiconductor device


Improved poly(vinyl chloride) compositions which exhibit improved adhesivity to polyamide which find particular utility in the construction of multi-layer structures, particularly for the fabrication of improved structures for use in forming electrical insulation structures for wires and cables. In one useful embodiment, the multi-layer structure has in the following order: a layer of PVC and a layer of polyamide in contact with the layer of PVC wherein the layer of PVC includes a vinyl chloride containing copolymer or a terpolymer which exhibits good solubility with the PVC, and which further provides good adhesivity with the PA. The vinyl resin is selected from the group consisting of vinyl chloride-vinyl acetate-vinyl alcohol terpolymers.

1. Field of the Invention
The present invention relates to improvements in poly(vinyl chloride) compositions which exhibit improved adhesivity to polyamide which find particular utility in the construction of multi-layer structures, particularly for the fabrication of improved structures for use in forming electrical insulation structures for wires and cables.
2. Description of the Prior Art
Multi-layer structures typically comprise at least two or more layers of materials featuring different physical properties, which properties are optimally optimized in order to satisfy a particular need at hand. The goal of the formation of such structures is to provide a structure which is directed to a particular need, and wherein the individual layers of the structures act to form a composite, and where each layer of material contributes to serve the function for which the structure is designed. Examples of such structures are well known to the art, and include composites which are used to form films, wherein each layer forming the film may feature a particular property, such as impermeability to a gas, or as a blocking layer to light or radio energy of a particular wavelength. Another example of such a structure may be those which would be used to form an insulation structure for an electrical conductor, where each layer forming a jacket about the conductor might feature improved abrasion resistance, or improved dielectric strength, or the like. Other uses of such structures are notorious and known to the art.
The use of such multi-layer structures is widespread with electrical conductors. These conductors typically consist of a wire conductor (which is frequently a metal, including copper) which is surrounded by a multi-layer structure. Examples such constructions include those taught in U.S. Pat. Nos. 3,576,940; 3,860,686; 4,079,191; 4,292,463; 4,327,248; 4,419,538; 4,472,597; 4,510,348; 4,626,619; and 4,691,082. Therein are disclosed a variety constructions wherein each of the layers may be a polymer, a metal, an elastomeric material, a fibrous material, etc., where each layer offers a particular advantage, i.e., dielectric strength, water impermeability, etc.
Two favorable materials which may be used in the construction of electrical conductors are poly(vinyl chloride) (hereinafter interchangeably referred to as "PVC") and polyamides (hereinafter interchangeably referred to as "PA"). These materials are favored as the PVC generally forms a good flexible insulator, while simultaneously, PA generally exhibit good abrasion resistance properties. Examples of electrical conductors having a multi-layer structure of an inner layer of poly(vinyl chloride) and an outer layer of polyamide are taught in Japanese Patent 59146105, British Patent 1257810, and Dutch Patent 6917475.
While such multi-layer structures comprising a layer of PVC and PA when used as electrical conductors are seen to perform well, such a structure retains drawbacks. One known problem is known to exist if the electrical conductor is stored outside and exposed to rain and high humidity. Upon contact with water, the polyamide layer tends to absorb moisture and expand considerably. This expansion causes the polyamide layer to swell away from the PVC layer and wrinkle. When the electrical conductor is then fed through a conduit, i.e. typically during installation, the wrinkled polyamide layer tears and the electrical conductor becomes unacceptable for use for its intended purpose. Further, a condition known to the art as "horse collaring" is known to occur, wherein sharp flexure of the wire causes separation of the polyamide and the poly(vinyl chloride) layers and the formation of bulges in the exterior layer in a direction transverse to that of the wife's length. The wire or cable exhibits an increased tendency to tear at such bulges, especially as the wire is subjected to mechanical stress as might be occasioned as the wire is pulled through a conduit, during installation of said wire or afterwards, due to vibration, thermal effects, etc.
It would be desirable to have a multi-layer structure where good adhesion exists between the PVC layer and the polyamide layer. Multi-layer structures having a PVC layer, an adhesive layer, and a polyamide layer are known. Japanese Patent 62041039 teaches an adhesive layer comprising an acid-modified olefinic polymer and an acid-modified halogen-containing olefinic polymer. German Patent 1669973 teaches an adhesive layer having: (1) a primer layer comprising a mixture of epoxide compounds, hardener, and solvent, and (2) an epoxy adhesive layer. Further, U.S. Pat. No. 4,868,054 illustrates a particularly successful embodiment of such a multi-layer structure, wherein the structure comprises (1) a layer of PVC, (3) a PA, and (2) an intermediate layer comprising an adhesive resin, plasticizer and a leveling agent.
While these multi-layer structures known to art may be beneficially used, there remains a continuing need in the art for multi-layer structures which would be particularly useful as insulation structures for electrical conductors wherein improved adhesion between the layers exists, particularly where the structure would be exposed to detrimental climatic conditions.

Poly(vinyl chloride) compositions exhibiting increased adhesivity to polyamide and multi-layer structures comprising the same


A method performed by a mobile device entails determining a current location of the mobile device, storing the current location as a breadcrumb (recorded) location of the mobile device, and performing an action with respect to the breadcrumb location when the mobile device has moved away from the breadcrumb location. The action may entail sharing the breadcrumb location with another device. Reverse geocoded address information may be provided for the breadcrumb locations.

Location-aware mobile devices, i.e. mobile devices having a position-determining capability, can provide a variety of useful functions such as navigation and location-based services. Sharing a current location of the mobile device with a contact or other device may be accomplished by sending location information to a location-management server or directly to the other device. Although this technology permits the relative locations to be plotted on a map, the address information associated with those locations is difficult to keep fresh as this requires very frequent calls to a reverse-geocoding server for updated address information as the device moves to new locations. Improved technologies for creating, managing and sharing location information are thus highly desirable.
It will be noted that throughout the appended drawings, like features are identified by like reference numerals.

Mobile device for creating, managing and sharing location information


Example implementations relate to devices, methods, and computer program products of communication networks in relation to, e.g., involved in initial access from an idle status, connection reestablishment, handover, or synchronization. A terminal apparatus may include: a control module configured to detect receipt of a group information indicative of a group of at least two network apparatuses, the group information being descriptive for a certain configuration of communication parameters enabling the terminal apparatus to communicate with anyone of the network apparatuses of the respective group, and request connecting to at least one of the network apparatuses of the group by use of the certain configuration.

The conventional network provides LTE and LTE-A UE handover so that the handover preparation and execution phase is network centric. Consequently, the decision to execute a handover is done by the network which might configure specific criteria.
In the first LTE version (Rel-8), attention is drawn to the design of a highly efficient handover functionality, which basically means as quickly as possible and also as simple as possible. The requirement for the execution of an intra- or inter-frequency handover to a known cell, i. e. the interruption time from the moment when the handover is commanded until the first available Physical Random Access Channel (PRACH) occasion in the new cell, shall be less than 50 ms. In the interruption requirement, a cell is regarded to be known by the UE if it meets the relevant cell identification requirement during the last 5 seconds. Otherwise the cell is unknown to the UE. If the UE has to handover to an unknown cell, then the handover interruption time will be 130 ms, e. g. 50 ms plus 80 ms for searching the unknown cell.
Hence, it is an object of the invention to improve such systems.


The present invention relates to methods of diagnosing, prognosing or treating diseases or disorders in which elevated levels of Abeta protein, including abeta1-42 are prevalent. In particular, the present invention relates to methods of diagnosing, prognosing or treating a major or minor depressive episode/disorder attributed to elevated levels of Abeta protein, including abeta1-42, found particularly in body fluids including whole blood, blood cells, serum, plasma, urine and CSF. The invention also relates to the treatment of these disorders by administering an agent that either prevents production of Abeta, prevents aggregation of Abeta fibrils, or that increases the degradation or clearance of Abeta. In addition, the invention provides a method of treating or preventing a major or minor depressive disorder comprising administering an agent that prevents or interferes with Abeta-induced neurotoxicity. The present invention also relates to pharmaceutical compositions comprising such agents and methods of screening for novel agents.

In the majority of major depressive disorders, little is known about a link between changes at the cellular or molecular level and nervous system structure and function. The paucity of detectable neurologic defects distinguishes major depressive disorders from neurological disorders where manifestations of anatomical and biochemical changes have been identified. Thus, the identification and characterization of cellular or molecular causative defects is desirable for improved treatment of major depressive disorders.
Depressive disorders come in different forms. A major depressive episode is manifested by a combination of symptoms that interfere with the ability to work, study, sleep, eat, and enjoy once pleasurable activities. The DSM-IV diagnostic criteria can be found in Tables I, II and III. Such a disabling episode of depression may occur only once but more commonly occurs several times in a lifetime. A minor depressive disorder is characterized by one or more periods of depressive symptoms that are identical to those found in major depression in duration, but which involve fewer symptoms and less impairment. Dysthymic disorder is a less serious form of depression and involves long-term, chronic symptoms that do not disable, but keep one from functioning well or from feeling good. Many people with dysthymia also experience major depressive episodes at some time in their lives. Bipolar disorder, also called manic-depressive illness is not nearly as prevalent as other forms of depressive disorders and is characterized by cycling mood changes, including severe highs (mania) and lows (depression).
Some types of depression appear to have a genetic component associated with their occurrence, suggesting that a biological vulnerability can be inherited. This appears to be the case with bipolar disorder. Furthermore, major depression seems to occur generation after generation. However, it can also occur in people who have no family history of depression.
Major depressive disorder is prevalent in a large number of elderly patients, resulting in a significant increase in the number of suicides in this population. The risk factors for late-life depression include female gender, unmarried status, having stressful life events and lack of a social support network. Major depressive disorder is characterized by any of a number of symptoms, including persistent sadness or anxiety, or feelings of emptiness, hopelessness, pessimism, guilt, worthlessness, or helplessness. There may also be a loss of interest or pleasure in hobbies and activities that were once enjoyed. Individuals with major depressive disorder may also experience decreased energy, or fatigue, or may have difficulty concentrating, remembering, or making decisions. They may also experience insomnia, early-morning awakening, or oversleeping, appetite and/or weight loss or overeating and weight gain. They may have thoughts of death or suicide and suicide attempts. They may also experience restlessness, irritability, and may exhibit persistent physical symptoms that do not respond to treatment, such as headaches, digestive disorders, and chronic pain.
Major mood disorders are also associated with many other deleterious health related effects and the costs with disability and premature death represent an economic burden of $43 billion annually in the United States alone. Rates of depression co-occurring with other medical conditions are as follows: myocardial infarction: 20-40%, Parkinson's disease: 40%, Alzheimer's disease: 30-35%, stroke: 25-50%, cancer: 3-50%, HIV/AIDS: 10-20%, rheumatoid arthritis: 12%, diabetes mellitus: 14-18%, chronic pain: 30%, disabling tinnitus: 60%, end-stage renal disease: 5-22% and spinal cord injury: 37% (Goldman et al. J Gen Intern Med 1999, 14, 569-580; Wyatt and Henter 1995, Soc Psychiatry Psychiatr Epidemiolm 30, 213-219). Despite the devastating impact of these disorders on the lives of millions, there is still uncertainty about the differential diagnosis of depression in the presence of these disorders (Goldman et al. 1999, J Gen Med 14, 569-80; Schatzberg 1998, J Clin Psychiatry, 59, suppl 6:5-12; Goodwin and Jamison, 1990 Manic-depressive illness, New York, Oxford University Press).
Current therapies can be categorized into the following major classes of agents: mood stabilizers: lithium, divalproex, carbamazepine, lamotrigine; antidepressants: tricyclic antidepressants (eg. Desipramine, chlorimipramine, nortriptyline), selective serotonin reuptake inhibitors (SSRIs including fluoxetine (Prozac), sertraltrine (Zoloft), paroxetine (Paxil), fluvoxamine (Luvox), and citalopram (Celexa)), MAOIs, bupropion (Wellbutrin), venlafaxine (Effexor), and mirtazapine (Remeron); and atypical antipsychotic agents: Clozapine, Olanzapine, Risperidone. However, the cellular and molecular basis for the efficacy of currently used mood-stabilizing and mortality-lowering agents remains to be fully elucidated (Manji et al. 1999, J Clin Psychiatry, 60, 27-39). A significant number of patients respond poorly to existing therapies such as lithium, while many others are helped but continue to suffer significant morbidity (Chou 1991, J Clin Psychopharmacol 11, 3-21). The recognition of the significant morbidity and mortality of the severe mood disorders, as well as the growing appreciation that a significant percentage of patients respond poorly to existing treatments, has made the task of developing new therapeutic agents that work quickly, potently, specifically, and with fewer side effects one of major public health importance (Bebchuk et al. Arch Gen Psychiatry 2000 57, 95-7).
Hence it would be highly desirable to measure a substance or substances in samples of whole blood, blood cells, serum, plasma, urine or cerebrospinal fluid (CSF) that would lead to a positive diagnosis of a major depressive disorder or that would help to predict whether an individual is prone to developing such disorder. For example, the identification of proteins and/or the nucleic acids encoding proteins that are associated with the onset and progression of a major depressive disorder would be desirable for the effective diagnosis, prognosis and treatment of afflicted individuals. Appropriate steps may then be taken to treat early on with existing therapies. Alternatively, if one could demonstrate an association between a certain substance, such as a protein, in the blood of a depressed individual, it may be possible to utilize this information to develop new modes of therapy to prevent or treat such depressive disorders.
Given that the CSF bathes the brain, changes in its protein composition may reveal alterations in CNS protein expression pattern causatively or diagnostically linked to the disease. Alternatively, if reasonable amounts of proteins associated with the major depressive disorder are secreted or released into body fluids by diseased tissue in the living patient at the onset and/or during progression of the disease, such information may be utilized for early diagnosis and expedite a treatment strategy. In many cases these alterations will be independent of the genetic makeup of the individual and rather directly related to a set of molecular and cellular alterations that contribute to the pathogenic phenotype.
Therefore, a need exists to identify sensitive and specific biomarkers for the diagnosis of major and minor depressive disorders and to assess a subject's risk for developing such disorders. There is also a need for a biomarker to assess the severity and to predict the outcome of a major or minor depressive disorder in living subjects or to assess whether a particular therapy is efficacious in treating a subject having such disorders. More importantly, the need exists for identification of a biomarker substance that may be found in a body fluid that can be obtained with minimally invasiveness procedures for early and specific diagnosis of a major depressive disorder. Additionally, there is a clear need for new therapeutic agents for major depressive disorders that work quickly, potently, specifically, and with fewer side effects.
Accordingly, the methods provided herein address this need. The citation of references herein shall not be construed as an admission that such is prior art to the present invention.

Methods for diagnosis of major depressive disorder


A valve assembly includes a body having a bore and a valve received within the bore for movement between an open position and a closed position. First and second sealing members are secured for movement with the valve and are positioned between the valve and the body such that an internal fluid pressure within the bore is applied to a first side of the sealing members and a common reference pressure is applied to a second side. An axial force imparted on the valve adjacent the second sealing member is less than an axial force imparted on the valve adjacent the first sealing member. A resiliently compressible member is positioned to bias the valve toward the normally open position. The valve is moved to the closed position when the internal fluid pressure exceeds a predetermined pressure and returns to the open position when the internal fluid pressure is substantially less than the predetermined pressure.

Devices for monitoring fluid flow and pressure in a hydraulic system and responding to pressure and flow transients that immediately follow a ruptured hydraulic line, hose or hydraulic device leak, so-called "hydraulic fuses," are known in the art. Hydraulic fuses are typically in-line valves that protect a hydraulic system or subsystem by sensing increased flow through the valve, resulting from a rupture line or leak, and closing the valve to block fluid flow upstream of the rupture to prevent further spillage.
While hydraulic fuses adequately protect a hydraulic system from fluid loss, they are generally incapable of protecting a hydraulic system from over-pressurization. To prevent over-pressurization, hydraulic systems or subsystems typically include a burst disk, pressure relief valve or other pressure relief device. While these devices effectively vent pressurized fluid when a hydraulic system or subsystem is over-pressurized, they exhibit a number of limitations. Among other limitations, burst disks must be replaced once they are ruptured. Additionally, unlike in-line hydraulic fuses, burst disks require additional plumbing for discharging pressurized fluid. Another limitation of burst disks is that they expose a downstream portion of the hydraulic system to a momentary high-pressure impulse prior to and during rupture. Moreover, burst disks have a tendency to fail due to low-pressure cycling fatigue.
Like burst disks, pressure relief valves also require additional plumbing for fluid discharge and expose a downstream portion of the hydraulic system to a momentary high-pressure impulse prior to the valve opening. Another limitation of pressure relief valves is that they are relatively large in size and weight, rendering them unsatisfactory for use in hydraulic systems where size and weight must be minimized.
For at least these reasons, a need exists for a relatively small and lightweight, in-line hydraulic device that monitors static and dynamic fluid pressure in a hydraulic system or subsystem and closes virtually instantaneously upon detection of an over-pressure condition to prevent a portion of the hydraulic system downstream of the valve from being exposed to the over-pressure condition and any associated pressure impulse. Moreover, a need exists for an in-line hydraulic device that automatically reopens when the over-pressurized condition returns to a safe pressure condition.


The invention is directed to an integrated stern bulb and flap for a water vessel, more particularly, a bulb having a main body section and a forebody section, the bulb positioned between first and second flap portions. The integrated stern bulb and flap provides improved power efficiency by reducing resistance at high speeds. The bulb of the integrated stern bulb and flap may be hollow, the interior being stowage space adding to the payload of the water vessel.

The USS Arleigh Burke (DDG 51) Class destroyer represents the latest in a distinguished lineage of combatants designed and developed by the U.S. Navy. It is one of the world's finest hull forms, optimizing speed, power, seakeeping, stability, and payload capacity, even though its initial design dates back nearly three decades. Since the first-of-class DDG 51 became operational in 1991, the hydrodynamic community has unveiled numerous advances in ship technology and design. The advances are applicable, not only to DDG 51 class ships, but also to other large hull ship forms, military and non-military.
The technological improvements were developed to enhance the operational performance and/or to foster reductions in operating and life cycle total ownership costs. The technological improvements include changes in propeller design, the addition of bow and stern end bulbs, and stem flaps, and improved rudder design. Cleaning techniques for cleaning the hull and propellers have also been developed to prevent increase in power and loss of propeller efficiency.
Stern flaps are extensions of the hull bottom surface created by a relatively small appendage welded to the transom of the ship. Stern flaps are known in the art, and have been proven during sea trials to reduce propulsive power, and to foster significant fuel cost savings, while increasing both ship endurance and top speed. The U.S. Navy has obtained several patents for stem flaps, such as, U.S. Pat. No. 6,038,995, U.S. Pat. No. 6,698,370 and U.S. Pat. No. 6,745,715. A stern flap based on U.S. Pat. No. 6,038,995, which could be retrofitted behind the transom wedge was successfully installed on all 28 Flight I and II hulls, DDG 51 through DDG 78.
Regarding the stern end bulbs, it is acknowledged that a ship moving in water generally creates a much larger bow wave than a stern wave. Thus, the most logical location for a bulb is at the bow because the large energy content in the bow wave is a potential source of more recoverable energy. Nevertheless, the stern end of the ship also generates waves that are a source of "wasted" energy. In contrast to the plethora of technical reports on bow bulb design and their universal and widespread usage at sea, there are only a few dozen technical reports and rare full scale applications of stern end bulbs. In order to be employed, it is desired that the stern end bulb design overcomes already enhanced performance with the existing stern flap.
Both stern flaps and stern end bulbs interact with the hull to produce a wave system that reduces the total wave resistance. In addition, the stern flap also reduces after-body resistance. For either body to be effective the drag reduction due to interactions with the hull resistance must be greater than the inherent drag of the device itself. The authors of this patent application have illustrated stern bulb/flap combinations conceptually in non-patent literature presentations, "Hydrodynamic Energy saving Enhancements for DDG 51 Class Ships" and "Stern End Bulb for Energy Enhancement and Speed Improvement". Apart from these conceptual illustrations, there is no prior art teaching of a stern end bulb and flap combination that is properly constructed to achieve the goals of reducing resistance on the hull, whilst avoiding the adverse effects of its structure.
In addition to improving the ship efficiencies as it relates to fuel consumption, it is also important to maintain efficiency while performing other mission related tasks. The USS Arleigh Burke (DDG 51) Class destroyer or other water vessels may perform other tasks related to monitoring the environment. This may involve the use of monitoring devices including, but not limited to, unmanned surface vehicles (USVs), unmanned underwater vehicles (UUVs), or towed arrays. The deploying of these sea-monitoring devices, and in the case of USVs and UUVs, the launching and recovering creates technical challenges that must be met. Some techniques for deployment may involve the use of davits or other lifting apparatuses for lifting the monitoring devices from the deck of the water vessel into the water below. Ramps may also be employed for lowering the monitoring devices into the water.
For more direct access to the water, some water vessels employ sea-level openings in their hulls through which the monitoring devices, such as USVs and UUVs may be passed. As stated above, the USS Arleigh Burke (DDG 51) Class destroyer has one of the world's finest hull forms, optimizing speed, power, seakeeping, stability, and payload capacity. Consequently, the addition of openings or penetrations to the hull structure may have adverse effects on vessel performance. Thus, it is desired to have a sea-level opening for launching and/or recovering monitoring devices that do not penetrate the hull or have adverse effects on vessel performance.

The United States of America as represented by the Secretary of the Navy


A synthetic aperture radar system (SAR) has a wide antenna beam. By using a Local Backprojection SAR Processor the requirment for computational power becomes practical. The SAR radar system is arranged to collect signal amplitudes over segments of the vehicle track, called subapertures, which are so short that the closest points imaged on the ground are in the far-field of said subapertures with respect to a wavelength, charactersitic of the radar signal, then to synthesize, from data obtained over each subaperture, a set of directive radar beams with an angular resolution determined by the subaperture length and the wavelength mentioned and each associated with a given position within the subaperture, to assume a topography for the ground surface, either based upon a topographical map or an assumption, for example that the ground is flat, and finally to compute the radar reflectivity of all ground points forming the image by a summation of the amplitudes for all subapertures at the range and beam direction determined by the platform position and the ground point.

The present invention relates to a SAR radar system. Such systems concern a SAR radar carried by a vehicle moving above the surface of the Earth or another planet and comprises means to obtain radar wavelength resolution images of the surface. The technique known as synthetic aperture radar--SAR--is well-known though until recently the achieved resolution has been much coarser than the wavelength. By ultra wide band, UWB, is here understood the use of a radar signal with a relative bandwidth of more than one octave. Such a large bandwidth will result in range resolution of wavelength order. A similarly high azimuth resolution calls for a radar antenna which collects signals over a wide aspect angle interval (in the regime 30.degree.-120.degree.). The antenna may either be steerable to illuminate one and the same patch on the ground as the radar vehicle passes by this patch, so called spotlight SAR, or the antenna beam may be sufficiently wide to continuously illuminate the full adopted aspect angle interval, so called strip map SAR. The combination of large relative bandwidth and a wide aspect interval for data collection enables the wavelength limit for resolution to be approached, as has been successfully demonstrated for instance in the CARABAS system, Swedish patent 8406007-8 (456 117), European patent 86900306.1 (202 320) and U.S. Pat. No. 4,866,446 and 4,965,582 all hereby incorporated by reference.
The vehicle carrying the radar may be an aircraft, an unmanned aerial vehicle, a so-called UAV, or a satellite. The radar may also be installed onboard a space vehicle for the purpose of exploring the surface of other planets.