A micromachined probe apparatus and methods for making and using same to characterize liquid in a fluidic channel and map embedded charge in a sample on a substrate are provided. The probe apparatus includes an integrated scanning tip and a dither actuation mechanism. The actuation is achieved using a bent-beam electrothermal actuator, and the probe tip is insulated from the actuator with a wide isolation gap. The device is fabricated by a modified micro electro-discharge machining process which allows electrical isolation within the micromachined structure using an epoxy plug. The apparatus may be used to measure changes in the external surface potential of a microfluidic channel as a function of varying pH of liquid inside the channel. The apparatus also may be used to map embedded charge in a thin layer on a substrate, showing it to be suitable for monitoring microelectronics manufacturing processes.

1. Field of the Invention
This invention relates to a micromachined probe apparatus and methods for making and using same to characterize liquid in a fluidic channel and map embedded charge in a sample on a substrate.
2. Background Art
U.S. Pat. Nos. 6,624,377 and 6,586,699 are related to the present application.
The following references are referred to in this specification:
[And52]J. R. Anderson et al., "Theory of the Vibrating CondenserConverter and Application to Contact PotentialMeasurements," AUSTRALIAN JOURNAL OF APPLIED SCIENCE, 3, 201,1952.[Ber95]P. L. Bergstrom et al., "Dielectric Membrane Technology forConductivity and Work-Function Gas Sensors," IEEEINTERNATIONAL CONFERENCE ON SENSORS AND ACTUATORS(Transducers, 1995), Stockholm, Sweden, pp. 993–996,1995.[But92]H. -J. Butt, "Measuring Local Surface Charge Densities inElectrolyte Solutions with a Scanning Force Microscope,"BIOPHYSICAL JOURNAL, 63(2), pp. 578–582, 1992.[Chu03]L. L. Chu et al., "A Micromachined Kelvin Probe for SurfacePotential Measurements in Microfluidic Channels and Solid-State Applications," IEEE INTERNATIONAL CONFERENCE ONSENSORS AND ACTUATORS (Transducers, 2003), Boston,USA, pp. 384–387, 2003.[Cis98]C. Cismaru et al., "Relationship Between the ChargingDamage of Test Structures and the Deposited Charge onUnpatterned Wafers Exposed to an Electron CyclotronResonance Plasma," APPL. PHYS. LETT., 72(10), pp. 1143–1145,1998.[Fan92]S. Fang et al., "Thin-Oxide Damage from Gate ChargingDuring Plasma Processing," IEEE ELECTRON DEV. LETT.,13, p. 288, 1992.[Fri97]J. B. Friedmann et al., "Plasma-Parameter Dependency ofThin-Oxide Damage from Wafer Charging During Electron-Cyclotron-Resonance Plasma Processing," IEEE TRANS.SEMIC. MFG., 10(1), 154, 1997.[Hei99]W. F. Heinz et al., "Relative Surface Charge DensityMapping with the Atomic Force Microscope," BIOPHYSICALJ., 76, pp. 528–538, 1999.[Hof97]A. Hoff et al., "A Novel Approach to Monitoring of PlasmaProcessing Equipment and Plasma Damage Without TestStructures," IEEE/SEMI ADVANCED SEMIC.MANUFACTURING CONF., 185, 1997.[Hun93]Robert J. Hunter, "Introduction to Modern Colloid Science,"OXFORD SCIENCE PUBLICATIONS, 1993.[Lud01]R. Ludeke et al., "Imaging of Oxide and Interface Chargesin SiO2-Si," MICROELECTRONIC ENGINEERING, 59, pp. 259–263,2001.[Man97]F. Man et al., "Microfluidic Plastic Capillaries on SiliconSubstrates: A New Inexpensive Technology for BioanalysisChips," IEEE MEMS, Nagoya, Japan, pp. 311–316, 1997.[Mor00]S. Morita et al., "Defects and their Charge Imaging onSemiconductor Surfaces by Non-Contact Atomic ForceMicroscopy and Spectroscopy," J. CRYSTAL GRTH., 210, pp.408–415, 2000.[Mur73]P. V. Murphy et al., "Blood Compatibility of PolymerElectrets," PROC. INT. CONF. ON ELECTRETS, CHARGESTORAGE, AND TRANSPORT IN DIELECTRICS, Miami Beach,FL, Electrochemical Society, Princeton, NJ, pp. 627–649,1973.[Nab97]W. Nabhan et al., "A High-Resolution Scanning KelvinProbe Microscope for Contact Potential Measurements on the100 nm Scale," REVIEW OF SCIENTIFIC INSTRUMENTS, 68(8),p. 3108, 1997.[Pet99]I. R. Peterson, "Kelvin Probe Liquid-Surface PotentialSensor," REVIEW OF SCIENTIFIC INSTRUMENTS, 70(8), pp.3418–3424, Aug. 1999.[Que01]L. Que et al., "Bent-Beam Electro-thermal Actuators-I:Single Beam and Cascaded Devices," J. MICROELECTROMECH.SYS., 10(2), pp. 247–254, 2001.[Rai96]R. Raiteri et al., "Measuring Electrostatic Double-LayerForces at High Surface Potentials with the Atomic ForceMicroscope," JOURNAL OF PHYSICAL CHEMISTRY, 100, pp.16700–16705, 1996.[Sur70]N. A. Surplice et al., "A Critique of the Kelvin Method ofMeasuring Work Functions," J. PHYSICS E: SCIENTIF.INSTRUM. 3, 477, 1970.[Tak02]K. Takahata et al., "Batch Mode Micro-electro-dischargeMachining," J. MICROELECTROMECH. SYS., 11(2), pp. 102–110,2002.
The vibrating Kelvin probe is an effective, non-invasive tool for the non-contact mapping of surface potentials [And52, Sur70, Nab97]. Since surface potential includes a component due to work function and another due to trapped charge, this tool can be used to map either quantity on a surface when the other is kept uniform. For example, trapped charge is monitored in semiconductor IC-fabrication because it has been correlated to the degradation of the device parameters. This function can be performed by mapping the contact (or surface) potential difference (CPD) between a probe and the sample wafer [Hof97]. Since the Kelvin probe method is a non-contact and non-destructive diagnostic, it can be used to monitor processes that are known to introduce trapped charges in wafers, such as plasma etch and deposition, ion implantation, and certain cleaning and wafer drying operations. Conventional plasma damage characterization approaches [Fri97, Cis98, Fan92] are based on electrical or surface analytical techniques, which cannot measure local charge distributions on patterned wafers. The ability to measure local charge distributed across patterns on production wafers can be a critical asset in predicting yield and longevity of devices.
Another potential application for scanning Kelvin probes is the mapping of surface charge in a biofluidic channel or tube [Bai98]. Charge distribution on the wall, acquired during manufacturing or in routine operation, can impact the function and behavior of the fluid in the channel. For example, it has been linked to cell adhesion and clotting of red blood cells on artificial surfaces [Mur73]. A Kelvin probe can be used to map the charge embedded in the wall by scanning the outside of the fluidic channel using the electrolyte in the channel as an electrode. A macro-scale Kelvin probe has also been used to measure the surface potentials of organic overlayers on poorly conducting liquid substrates [Pet99], and a micromachined device based on this principle has been developed for gas sensing [Ber95].
Relative surface charge density has been measured suing atomic force microscopy (AFM) in an aqueous electrolytic ambient [But92, Rai96, Hei99]. When the AFM tip is in close proximity to the sample, the electrostatic force produced by their overlapping electrical double layers is detected by the AFM tip and correlated to charge density. This method is effective for measurements of biological samples in an aqueous environment. In non-aqueous environments, non-contact AFM methods have recently been used for the mapping of surface [Mor00] and interface [Lud01] charge on a semiconductor. However, these experiments require ultra high vacuum (UHV) and, in some cases, cooling of the system to liquid He temperature, which limit their application.

Micromachined probe apparatus and methods for making and using same to characterize liquid in a fluidic channel and map embedded charge in a sample on a substrate

The Regents of the University of Michigan


An LNG refueling facility includes a nozzle for mating with the receptacle on a motor vehicle to deliver a flow of LNG to the vehicle's tank. The nozzle is supplied with a flow of dry gas to purge moisture-laden air from around surfaces which mate with the receptacle to prevent freezing of moisture on the mating surfaces when the nozzle turns very cold. The nozzle also includes a boot enclosing mechanical linkages for latching the nozzle to the receptacle. Dry gas is supplied to the interior of the boot to displace air from around the mechanical linkages and thereby prevent moisture from freezing onto the mechanical linkages.

Interest in the use of liquid natural gas (LNG) as a motor vehicle fuel has increased dramatically in recent years. Whole fleets of government and industry vehicles have successfully been converted to natural gas, and some private individuals have converted their vehicles as well. Congress recently passed an energy bill which would require further increased use of alternative fuels in government and private fleets.
Several factors have influenced this increasing interest in natural gas as a motor vehicle fuel. LNG is relatively inexpensive. It also burns very cleanly, making it much easier for fleets to meet more restrictive pollution emission standards. However, handling LNG remains a significant problem.
Vehicles using LNG in place of gasoline are equipped with a cryogenic tank in place of an ordinary gas tank. A cryogenic tank is very well insulated and sealed. It is able to maintain the LNG at sufficient low temperatures for a period of time sufficient for a fleet vehicle to burn most of the LNG before significant vaporization occurs.
LNG fueling facilities are high capacity facilities generally designed to service large fleets of vehicles. A conventional LNG fueling station includes massive LNG storage tank, a pump for pumping the LNG, and a dispensing mechanism that includes a nozzle assembly that is used to connect and to disconnect quickly an LNG line to and from the cryogenic tank on the vehicle. The nozzle assembly includes a connector that is designed to quickly couple to and uncouple from a complementary connector on a receptacle on the vehicle's tank. Because LNG in its gaseous or vapor state is potentially explosive when mixed with air, valves located in each receptacle assure that no LNG or gaseous methane escapes from either of the connectors prior to complete coupling. Upon proper coupling, the valves are automatically displaced from their respective valve seats to allow LNG to flow in the vehicle's tank. A locking mechanism insures that the coupling halves are locked together prior to the opening of the valves and to prevent accidental disconnection of the receptacles during pumping.
LNG flowing through the nozzle assembly rapidly cools its exterior surface. Moisture in the atmosphere tends to condense and to freeze on the nozzle assembly. The ice is extremely undesirable, as it interferes with coupling of the nozzle to the receptacle on the motor vehicle. Ice also tends to form between the nozzle and the receptacle. Any ice that has accumulated on the nozzle assembly melts quickly at points of contact with the warmer receptacle. The moisture, in a liquid state, then spreads quickly and evenly. When cryogenic methane begins to flow through the receptacle, the moisture quickly re-freezes and effectively glues together the coupling, making it very difficult to detach the nozzle assembly from the vehicle receptacle. The ice can also form on the mechanical linkages of the latching mechanism, making it difficult to unlatch the nozzle.
The conventional solutions of removing ice are certainly inconvenient and, in the case of the hammer, potentially destructive and dangerous. Furthermore, breaking or melting of the ice is time consuming and slows refueling. Since LNG stations tend to be expensive to install and maintain, fleet operators often demand that LNG stations be capable of refueling at a rate of one vehicle every few minutes. Ice formation is thus an impediment to efficient operation of LNG refueling stations. It also discourages use of LNG dispensing stations by persons who are not specially trained, such as retail consumers, and therefore impedes more wide-spread acceptance of LNG as a fuel for motor vehicles.

Apparatus and method of preventing ice accumulation on coupling valves for cryogenic fluids


A process for preparing a block oligocarbonate is disclosed. The oligocarbonate conforms to ##STR1## where R denotes hydrogen or ##STR2## and where A denotes an aromatic carbonate structure conforming to ##STR3## where Ar is an aromatic radical, n is 2-6 and where B is the residue of an aliphatic polyol is disclosed. In the process a high molecular weight aromatic polycarbonate is reacted, in the melt and in the presence of a catalyst, with an aliphatic polyol. The block oligocarbonate is useful as a reactant in a process for the preparation of copolymers.

Polycarbonate molding compositions containing an aromatic carbonate polymer and an ester have been disclosed in GB 1,567,517. Accordingly, esters of certain organic acids and certain alcohols can be incorporated in a thermoplastic aromatic polycarbonate resulting in a resin having release properties. In addition, the composition is said to be compatible with polycarbonate melt. The incorporation of the esters in the polycarbonate composition in accordance with the '517 document can be effected by admixing the ester with granules of polycarbonate composition and subsequently extruding these through an extruder under standard conditions. The esters may also be incorporated by dissolving them in a solvent in which the polycarbonate is dissolved and subsequently recovering the polymer composition from the solvent by known methods.
The preparation of relevant copolycarbonates was disclosed by Schreckenberg in U.S. Pat. No. 4,281,101. The process involved solution reaction of oligomers with diphenols. In accordance with the process disclosed in the '101 document, an aliphatic aromatic polycarbonate with diphenol carbonate end groups is prepared by reacting in the melt an aliphatic diol,carbonic acid bis aryl ester--for example diphenyl carbonate--and diphenols. The resulting polycarbonate is characterized in that each of its end groups constitute a residue of one diphenol. The polycarbonate disclosed in the '101 document are unsuitable in the practice of the present invention for the preparation of block copolycarbonates. It was surprisingly found that in instances where each of the end groups constitute residues of less than 2 diphenol units, the oligocarbonate was unsuitable for the preparation of copolycarbonates by melt blending with a polycarbonate resin. The product made with such unsuitable oligocarbonate was typically delaminated.

Process for the preparation of a block oligocarbonate


The microphone of a breathing mask such as an aircraft flight crew oxygen mask is disabled during inhalation to prevent transmission of air flow sounds. In the preferred embodiments, selected mechanisms determine when breathable gas has been delivered to the mask and in response, disable the microphone by disconnecting it during this time. In another embodiment, a cover shifts into position over the microphone to prevent or reduce reception of sounds thereby during delivery of gas to the mask.

1. Field of the Invention
The present invention is concerned with the field of breathing masks and in particular with aircraft flight crew oxygen masks.
2. Description of the Prior Art
Most aircraft flight crew oxygen masks include a demand breathing regulator and a microphone. To communicate with other crew members or with the control tower, for example, the wearer of a prior art mask activates the microphone which converts received sounds into audio signals for transmission. The sounds received by the microphone include not only the wearer's voice, lude not only the wearer's voice, but background noise as well. When the wearer is inhaling, the sound of gas flow through the mask's breathing regulator is often particularly loud and is transmitted as noise having a large component comparable in both frequency and intensity to the sounds made by a person speaking. When two or more members of a flight crew are wearing masks at the same time and one of the crew members is speaking, the noise generated during inhalation by the others can seriously interfere with hearing or understanding the voice transmission of the crew member who is speaking.
As can be appreciated, this can present a very serious situation because usually two or more crew members are not on oxygen unless a flight problem has developed. In such circumstances, clear communications are especially important, but are the very circumstances that present the greatest interference with communications. Electronic filtering or dampening cannot be used without also filtering the sounds of speech. Accordingly, the prior art points out the need for a microphone equipped breathing mask that does not interfere with communications.

Microphone signal attenuating apparatus for oxygen masks


This invention covers improved electronic time-temperature indicators with a visual output, and other devices and methods by which the thermal history of a complex material, which may not obey a simple exponential Arrhenius law degradation equation, may be monitored, and the subsequent fitness for use of the tracked material may be quickly ascertained. In particular, the invention discloses a rapidly reprogrammable electronic time-temperature tag that may be easily customized with the thermal time-temperature stability profile of an arbitrary material, using electronic data transfer methods. Using this device, a single, low-cost, generic time-temperature tag may be mass-produced, and then subsequently programmed to mimic the stability characteristics of nearly any material of interest.

1. Field of the Invention
This invention covers improved electronic time-temperature indicators with a visual output, improved thermal modeling algorithms, and other devices and methods by which the thermal history of a material may be monitored, and the subsequent fitness for use of the tracked material may be quickly ascertained by visual or other means. The invention is well suited to monitoring the thermal stability of complex materials that are not well characterized by the standard Arrhenius exponential degradation curve.
2. Description of the Related Art
Many materials in use in commerce, medicine, and other areas are perishable. That is, the materials have a tendency to deteriorate with time, and this tendency to deteriorate is often accelerated by exposure to higher temperatures. This tendency to deteriorate is often designated as a material's "stability". A material that deteriorates slowly in response to higher temperatures over long periods of time is said to have a "high stability". By contrast, a material that deteriorates quickly in response to higher temperatures is said to have a "low stability". For simple materials, thermal degradation processes are usually well characterized by the well-known Arrhenius equation:
                    k        =                  C                                                                          ⅇ                          (                                                -                  E                                RT                            )                                                          (        1        )
Here k is the rate of deterioration, C is a constant, E is the activation energy of the reaction, R is the universal gas constant, and T is the temperature in degrees Kelvin.
For more complex materials, however, the simple Arrhenius equation is often not sufficient. Complex materials can be composed of many different molecular entities, each with different activation energies and possibly different phase transition temperatures. As a result, the thermal degradation curve for more complex materials can often be a relatively complex function, which may have inflection points, sharp transitions, and other significant deviations from Arrhenius equation (1).
Examples of deterioration includes spoilage in the case of biological materials, loss of potency in the case of drugs, loss of chemical reactivity in the case of chemicals, or alternatively formation of unwanted contaminants. Excessive deterioration eventually results in the material in question being rendered unfit to use, or even rendered dangerous. Thus for commerce, medicine, and other areas, the rapid detection of materials rendered unfit to use by an unacceptable thermal history is very important.
Additionally, there are alternative situations where a material must undergo a certain minimal thermal history before it becomes fit for use. There are many materials, and material treatment processes, commonly used for construction, manufacturing, food preparation, and pharmaceutical preparation, such as concrete setting, epoxy hardening, biological fermentation, cooking, pasteurization, sterilization and the like, where the material needs to be properly cured, incubated, or heat treated before the material is fit to use. Since curing, incubation, or heat treatment processes are often temperature dependent, typically taking longer to proceed at lower temperatures, such materials must undergo a certain minimal time-temperature history before they are fit for use.
As a result, visual time-temperature indicators (TTI) are widely used in many areas of commerce. These are typically small devices that are affixed to a container of thermally sensitive material. The TTI shares the same thermal history as the material, and gives the user a visual warning if the material has had an improper thermal history.
Visual time-temperature indicators are often used to verify that a perishable, temperature sensitive, product has been transported from the manufacturer to the user via a transport process that has preserved the "cold chain". Here, a "cold chain" means a continuous system for conserving and preserving materials at precise refrigerated temperatures from production to use, so that the integrity of the materials is assured.
There are several different types of visual time-temperature indicator in present-day use. These are chemically based, and follow the simple exponential Arrhenius decay equation. As previously discussed, however, one drawback of such Arrhenius decay type indicators, is that not all materials follow simple Arrhenius decay kinetics throughout all temperature ranges of interest. As a result, prior-art TTI cannot adequately monitor all materials.
FIG. 1 shows a graph of the stability of a material with a simple Arrhenius decay curve (1), and a material with a more complex decay curve (2). Here the curved exponential Arrhenius decay equation has been linearized by plotting 1/(Temperature) in degrees Kelvin on the "X" axis, versus the logarithm of the material's lifetime (in hours) at various temperatures on the "Y" axis. Note that although material (1) can be successfully monitored with a simple (i.e. linear function in 1/Temperature vs. log lifetime plots) Arrhenius-curve TTI (3); material (2) requires a more sophisticated TTI (4) capable of accurately reproducing more complex (i.e. non-linear function in 1/Temperature vs. log lifetime plots) thermal degradation curves. Prior to the present invention, however, no such sophisticated visual TTI devices (4) existed.
For the purposes of this discussion, "simple" temperature functions (or stability curves) are defined as exponential Arrhenius curves that produce a line with a single defined slope and intercept when the temperature function is plotted on 1/(Temperature ° K) versus log (lifetime) plots; and "complex" temperature functions (or stability curves) are defined as functions that produce curves, or higher order shapes when the temperature function is plotted on 1/(Temperature ° K) versus log (lifetime) plots, such that a single slope and intercept is inadequate to describe the resulting plot.
There are several different brands of visual Arrhenius-type time-temperature indicators in current use. For example, TempTime Corporation, Morris Plains, N.J., produces the Heatmarker® Time-temperature indicator for medical use. This indicator, often used to insure the integrity of vaccines in third-world countries, relies upon the progressive darkening of a chemical indicator, normally placed in the center of a "bulls eye" visual colorimetric reference pattern. Upon initial production, the chemical indicator is light in color, and the center of the "bulls eye" is lighter than the surrounding area. However upon exposure to an excessive amount of temperature for an excessive amount of time, the center of the bull's eye becomes darker than the surrounding area. A user may thus quickly and easily assess the integrity of any material associated with the indicator by simply noting if the center of the bulls eye is lighter or darker than the surrounding colorimetric reference material.
The chemistry techniques underlying this methodology is disclosed by Baughman et. al. in U.S. Pat. No. 4,389,217, Prusik et. al. in U.S. Pat. No. 6,544,925; and in other patents.
An alternative chemically based visual time-temperature indicator is the MonitorMark™ indicator, produced by the 3M corporation, Saint Paul, Minn. The MonitorMark uses a wicking material, along with a colored indicator that slowly migrates up the wick at a rate that is dependent on time and temperature. The user may thus quickly ascertain how far up the wick the colored indicator has migrated, and quickly assess if the material associated with the time-temperature indicator is fit to use.
The chemistry techniques underlying this technology is disclosed by Arens et. al. in U.S. Pat. No. 5,667,303, and in subsequent patents.
There are other types of time-temperature indicator that do not produce a visible output, but rather require the use of instruments to interrogate the indicator, and determine the state of the indicator. For example, the Bioett Corporation, Sweden, produces a radio frequency identification (RFID) non-visual time-temperature indicator. This indicator combines a passive RFID unit with an Arrhenius type, enzyme based, degradable circuit component, such that as the indicator is exposed to excessive amounts of temperature for excessive amounts of time, the RFID signature of the tag changes. The techniques underlying this methodology are disclosed by Sjoholm et. al. in WIPO application WOO 125472A1.
Although this approach lends itself to very low cost time-temperature sensors, the lack of visual output is inconvenient for most users, who typically are not equipped with sophisticated RFID reading equipment. As a result, users without this specialized equipment will be unable to ascertain the status of the sensor. An additional drawback of Sjoholm et. al. is that the precise stability characteristics of this device are dependent upon tuning the specific degradation of a chemically based (enzymatic) Arrhenius type time-temperature sensor to match the degradation characteristics of an arbitrary product. This is a time-consuming and burdensome process that may not always result in a precise stability match between the characteristics of the chemical time-temperature indicator, and the characteristics of the monitored material.
In addition to time-temperature indicators, which integrate time and temperature, and then make some sort of internal judgment as to if the unit has exceeded some preset criteria, there are a number of time-temperature data logging devices on the market. These logging devices typically store a record of the temperature history of the logger, and make the detailed history available for download to the user. However data loggers of prior art do not attempt to interpret this detailed history. Thus for prior art data logger devices, the interpretation of the relatively long and complex table of time and temperature log entries generated by the logger usually requires downloading the data, followed by a relatively sophisticated analysis by the user. It is clear that such devices impose a considerable burden on unsophisticated users, who simply want to quickly know if the material associated with the device is appropriate for use or not.
One example of a prior art data logger device is the Dallas Semiconductor iButton Thermochron series of temperature logger products. This data logger consists of a roughly ¾ inch diameter metal button that contains an internal battery, thermocouple, microprocessor, and data storage means. The iButton takes up to one million temperature readings over a time period of up to ten years, and stores these readings in its internal memory. Users may access the data by making electrical contact with the iButton through its 1-Wire electrical interface, and downloading the data into a computerized reader. This data then may be manipulated as the user desires, and assessments of the degradation status of the associated product may subsequently be made after additional analysis.
The techniques underlying these methods are taught by Curry et. al. in U.S. Pat. No. 6,217,213.
Other data loggers are also on the market. These include the HOBO time-temperature data logger produced by Onset Computer Corporation, Pocasset, Mass., and others. As does the Thermochron product, these other data loggers also acquire data from temperature sensors, store the data and time in an onboard memory, and make the data available for download and subsequent analysis by sophisticated users.
Electromechanical data loggers are also on the market. For example, the Monitor In-transit temperature recorder, produced by Monitor Co, Modesto, Calif. uses a battery operated, quartz-controlled clock motor to move a small strip of chart recorder paper past a bimetallic, temperature responsive, scribe to produce a visual strip-chart containing a detailed record of the thermal profile of the unit.
Another type of device is the temperature alarm. An example of this later type of device is the TagAlert® monitor, produced by Sensitech Corporation, Beverly Mass. This is a small electronic device, with a microprocessor, temperature sensor, battery, and display all enclosed in a single case. The device can be factory customized to notify the user if the device has exceeded any one of 4 preset alarm conditions, such as temperature went too low, temperature went too high, total time spent at a predetermined first temperature is too long, and/or total time spent at a pre-determined second temperature is too long. The device may be customized to respond to this narrow set of temperature alarm values, and pre-determined temperature-time alarm values.
The technology behind the TagAlert monitor was originally disclosed by Berrian et. al., U.S. Pat. No. 5,313,848; and subsequently reexamined and reissued as U.S. Pat. No. Re. 36,200.
In the broadest form, the device of U.S. Pat. No. Re 36,200 is a system, with an enclosed temperature sensor, which generates a time series of temperature measurements, stores some of the past time and temperature measurements, and uses some of these stored temperature measurements to generate an output signal. U.S. Pat. No. Re 36,200 differs from prior art electronic digital thermometers which also perform time series signal processing, and which also have digital memories of past readings, such as those taught by U.S. Pat. No. 4,536,851, in that the temperature sensor of U.S. Pat. No. Re 36,200 is enclosed in a housing, rather than on the surface of the housing or outside of the housing. In this respect, U.S. Pat. No. Re 36,200 has some aspects in common with electronic digital temperature controllers for portable medical instrumentation.
More specifically, however, the device of U.S. Pat. No. Re 36,200 may be viewed as a limited type of integrating time-temperature indicator, in that this device uses a sensor (isolated and protected from the external environment by a housing that also contains the other circuit components) to generate the time integral of temperature outside of an acceptable range, or above or below a predetermined threshold temperature, and store or otherwise make use of this value for output purposes.
Although the device of U.S. Pat. No. Re 36,200 teaches displaying a visual output means, the system has a number of drawbacks. In particular, the method is generally incapable of realistically modeling (or simulating) material thermal stability profiles, and thus is prone to generate inaccurate results.
U.S. Pat. No. Re 36,200 teaches a device that is essentially programmed by four parameters (the upper and lower acceptable temperature, the upper acceptable time value, and the lower acceptable time value). This method is very simplistic, however. The method assumes, for example, that no thermal changes occur between the upper and lower acceptable range conditions. Additionally, the method assumes that beyond the acceptable range limits, (at least up until an optional set of instantaneous temperature "stop" limits), all degradation occurs at the same rate regardless of temperature. As will be discussed in more detail later on, most materials have much more complex thermal degradation profiles, and are poorly monitored by such simplistic approaches.
Because of this lack of proper thermal modeling, for the purposes of this patent, the art of U.S. Pat. No. RE 36,200 will be designated as a "thermal alarm". This nomenclature is consistent with the unit's commercial designation (TagAlert®).
The prior art for time-temperature indicators thus may be separated into three main types. One type consists of visual indicators, which use chemical means to mimic the Arrhenius degradation characteristics of a material of interest. These visual indicators may be directly interrogated by unsophisticated users using no additional equipment, and impose no significant analytical burden on the recipient of the material of interest.
The second type consists of non-indicating electronic time-temperature monitors, and electronic data loggers. This second type also monitors the time and temperature by chemical or electronic means, but does not output the data in a manner that is readily accessible to unsophisticated users without additional equipment. Rather, this second class of electronic device requires specialized reading equipment, and may additionally require sophisticated data analysis on the part of the recipient of the material of interest.
The third type consists of electronic time-temperature alarms. This device, exemplified by the Sensitech TagAlert® monitor, does not attempt to integrate the progressive effects of time and temperature over all probable thermal histories, but rather simply informs the user in the event that a limited number (absolute low, time 1 at low 1 exceeded, time 2 at high 2 exceeded, absolute high) of predetermined time-temperature excursions have taken place. U.S. Pat. No. 6,320,512 teaches similar time-temperature alarm methods, using circuit methods similar to those taught by Texas Instruments (MSP430 family Software Users Guide, 1994, p 9–18 to 9–21; MSP430 Family, Metering Application Report, 1997, p 42–45) and others.
Such devices are useful for monitoring conditions during shipping, such as determining if shipment ice packs have melted, detecting if a shipping container has been exposed to temperatures over 50° C., or detecting other standard shipping faults, but are less useful for monitoring the individualized stability profiles of arbitrary materials.
Radio-frequency based time-temperature indicators of the prior art, such as the previously mentioned device of Sjoholm et. al. (WO0125472A1), which contain Arrhenius based chemical timers, have many of the same accuracy drawbacks as chemically based visual indicators.
As a result of deficiencies in prior art TTIs, the present practice is to be conservative. That is, chemical time-temperature indicators are usually set to degrade more quickly than the material of interest. Although this scenario will insure that the user does not inadvertently accept degraded material, it is inefficient. In many cases, material that is, in fact, still good may be inappropriately discarded due to poor time-temperature indicator accuracy. Of course, the alternative scenario, in which the chemical time-temperature indicator fails to adequately warn that the tracked material is degraded, is both unacceptable and potentially dangerous.
By contrast, electronic data loggers have a different set of problems. Although these devices collect a full set of accurate time-temperature data, which may be used to determine if a material is acceptable or not, the data is in a difficult to interpret form. As previously discussed, many or most material recipients are unsophisticated, and are unlikely to have the equipment or specialized knowledge in order to read an electronic device, or to interpret a complex chart-recorder graphical output. As a result, many unsophisticated users, receiving material. associated with an unreadable or hard-to-read electronic tag, are likely to ignore the tag altogether. As a result, users may inadvertently use material that has been degraded by an unacceptable thermal history.
The temperature alarms of the prior art, such as U.S. Pat. No. Re. 36,200, also are not ideal. These alarms can only be adjusted to trigger on a limited set of fixed unacceptable temperature for a fixed unacceptable time combinations. They are not well suited to accurately mimic the stability characteristics of arbitrarily selected materials. As a result, they have a tendency to either trigger too soon, or too late, which can result in either waste, or inadequate warning.

This patent is subject to a terminal disclaimer.

Electronic time-temperature indicator and logger


A process for the production of a low-sulfur diesel gas oil having a sulfur content of 0.05% by weight or lower and having a Saybolt color number of -10 or higher, from a petroleum distillate having a sulfur content of 0.1 to 2.0% by weight and having an inferior color and inferior oxidation stability comprises contacting the petroleum distillate with hydrogen in the presence of a hydro-treating catalyst which has at least one metal supported on said porous carrier, at a temperature of 350.degree. to 450.degree. C., and a pressure of 45 to 100 kg/cm.sup.2 in the first step to thereby produce materials having a sulfur content of 0.05% by weight or lower, and contacting further the materials issued from the first step with hydrogen in the presence of a hydro-treating catalyst which has at least one metal supported on said porous carrier, at a temperature of 200.degree. to 300.degree. C., and a pressure of 45 to 100 kg/cm.sup.2 in the second step to thereby produce the finished low-sulfur diesel gas oil.

(1) Field of the Invention
The invention relates to a process for the production of a low-sulfur diesel gas oil having a low-sulfur content and a good color from a petroleum distillate. More particularly, the invention relates to a process for the production of a low-sulfur diesel gas oil having a sulfur content of 0.05% by weight or lower and having a Saybolt color number of -10 or higher, from a petroleum distillate having a sulfur content of 0.1 to 2.0% by weight and having an inferior color and inferior oxidation stability.
(2) Description of the Prior Art
At present, domestic diesel gas oils are produced by blending a desulfurized gas oil fraction obtained by conventional desulfurization of a straight-run gas oil with a straight-run gas oil fraction, a straight-run kerosine fraction, a gas oil fraction obtained by petroleum cracking, or the like to thereby provide a product having a sulfur content of 0.4 to 0.5% by weight.
Recently, due to rising concern regarding environmental problems, further reduction of NO.sub.x and particulate matter evacuated with exhaust fumes from diesels is required.
The basic requirements requested to the petroleum manufacturers are as follows:
1. First, the sulfur content of 0.4 to 0.5% by weight as set forth in the present standards must be lowered to the first-phase targeted exhaust fume standard of 0.2% by weight.
2. The sulfur content of 0.2% by weight must be further lowered to the second-phase targeted standard of 0.05% by weight in stages.
3. As for the color, no targeted standards have been fixed yet; however, each oil refining company has been carrying out quality control for diesel oils by setting a reference standard for color in various scales such as Saybolt, ASTM, APHA color numbers, or the like from an independent standpoint.
Especially, cracked gas oils used as a base gas oil, for which a large increase in demand in the future has been forecasted, are very poor in color; therefore, a distinct improvement on the present color level is also required. Japanese Patent Laid-Open Application No. 3-86793 proposes a two-step hydro-treating process for the production of a diesel gas oil having a sulfur content of 0.2% by weight or lower which is the first-phase targeted standard. However, under the conditions of the process such as a pressure of 10 to 40 kg/cm.sup.2, a temperature of 280.degree. to 370.degree. C., a liquid hourly space velocity, LHSV, of 0.5 to 5.0 hr.sup.-1 in the first step, and a pressure of 10 to 40 kg/cm.sup.2, a temperature of 150.degree. to 325.degree. C., an LHSV of 0.5 to 5.0 hr.sup.-1 in the second step, it is extremely difficult to meet the second-phase targeted standard of sulfur content of 0.05% by weight.
Further, under a pressure of 40 kg/cm.sup.2 or lower in the second reactor in this case, it is extremely difficult to meet the requirement for color i.e. the reference standard for the color of finished products, because the desulfurized oil to be fed into the second step has already been treated at a much higher temperature in the first step in order to meet a sulfur content of 0.05% by weight and thus has a poor color. Such difficulty is encountered especially remarkably in hydro-treating of a cracked gas oil which is not good in color.
U.S. Pat. No. 4,755,280 teaches a two-step hydro-treating process for improving the color or oxidation stability of hydrocarbon compounds wherein an Fe-type catalyst is employed in the second reactor in order to improve the color and oxidation stability. However, it is known that the hydro-treating activity of the Fe-type catalyst is readily poisoned with hydrogen sulfide and the like (Japanese Patent Laid-Open Application No. 62-84182). Therefore, the amounts of sulfur and nitrogen compounds such as hydrogen sulfide and ammonium present in the feedstock to be fed to the second step must be lowered to a total amount of about 10 ppm or lower prior to feeding.
As it is seen from the description of the above process, when sulfur and nitrogen compounds such as hydrogen sulfide and ammonium present in the materials issued from the first step must be removed prior to feeding the materials into the second step, it is necessary to install additional units such as a vapor-liquid separator, a stripper for the stripping of the absorbed hydrogen sulfide and ammonium from the rich oil, and a washing tower for the removal of these compounds present in the rich gas; therefore, a commercial plant of this type is very costly, and increases the costs of operation unpreferably.
U.S. Pat. No. 3,841,995 proposes a two-step hydro-treating process for the improvement of the color and odor of hydrocarbon compounds. However, in the process a noble metal catalyst such as Pt is employed in the second reactor; thus, the hydro-refining activity of the catalyst is readily poisoned by hydrogen sulfide and the like. Therefore, it is necessary to remove the sulfur and nitrogen compounds such as hydrogen sulfide and ammonium present in the materials issued from the first step to thereby provide a hydrogen sulfide- and ammonium-free feedstock to be fed to the second step. This is costly in a similar manner as described for the process disclosed by U.S. Pat. No. 4,755,280.

Process for the production of low-sulfur diesel gas oil


A method and apparatus for a Web-enabled transaction and matter management application are described. In one embodiment, the application is centered around a user-friendly home navigation page designed to facilitate convenience for the user in accessing information or entering and tracking data. All information is sorted by project or matter name. A client user may view information one matter at a time, all matters at once, or any user-specified number of matters. Access is restricted to authorized users with password access rights. The application enables the tracking of information that is beneficial to all levels of the user's organization, that is substantive and relevant to different levels of the user's staff, and that aids the client in making informed decisions regarding its current transactions and documents relating thereto.

The disclosures herein relate generally to communications software applications and more particularly to a Web-enabled transaction and matter management system.
The needs of a company for effective channels of communication among its own employees as well as between those employees and its service providers have never been greater. For example, the current volume and velocity of transactions and matters have strained traditional ways of working and communicating between law firms or other outside service providers and their clients. Many clients have expressed an interest in harnessing the power of technology, in general, and the Worldwide Web (the "Web"), in particular, to create a competitive edge that enables them to better manage their transactional and matter processes.
Recent advances in technology, particularly the growth in the acceptability of the Web, have created the possibility of applying technology to develop more innovative and efficient ways of working and communicating between clients and their outside service providers (e.g., law firms, accounting firms, advertising agencies); however, most applications available today fall far short of meeting the clients' needs and expectations.
Other currently available information management applications are targeted primarily to a company's in-house service providers and their staff—to the exclusion of the business people. In addition, applications are largely passive, with the company's employees merely viewing information entered by an outside service provider. The reports generated by such applications are also fairly limited in scope, including, for example, cost and expense-centered reports.
Therefore, what is needed is a system for providing more effective channels of communication between a client and its employees and the client's outside service providers.


An apparatus for recording/reproducing optical information on/from an optical card, in which optical information is recorded and/or reproduced on/from said optical card by relatively moving the optical card and an optical head with respect to each other in a track direction and a tracking direction; the optical head and optical card are driven by a driving motor with respect to each other under a normal moving condition of the apparatus; in the apparatus it is arranged such that an anomalous condition of the relative movement between the optical card and the optical head is detected and when this anomalous condition is detected, an operational movement of said apparatus is changed such as that for instance, as to stop an electric supply to the driving motor.

1) Field of the Invention
The present invention relates to an apparatus for recording and/or reproducing optical information on/from a card-like information recording medium, such as an optical card, and particularly relates to an apparatus in which an optical head provided in the apparatus and the recording medium are arranged to be relatively moved with respect to each other in a longitudinal direction of the recording medium and a direction perpendicular thereto. According to the present invention, the relative movement of the optical head and the recording medium is controlled so as not to damage the optical card and the recording medium.
2) Description of the Related Art
On an optical card, it is impossible to rewrite optical information, once information has already been written on. However, the optical card has a great memory capacity, i.e. about several thousand times to ten thousand times as large as that of a magnet card. The optical card has its memory capacity of about from one to two megabytes, so that a great number of applications such as a bankbook, a pocket map and a prepaid card for shopping can be considered on the optical card.
Many constructions of optical cards have been suggested; and one of the constructions of the optical card, which has been suggested by the applicant in Japanese Preliminarily Laid-open Publication No. 63-37836, is shown in FIG. 1. On the optical card 11, there is provided an optical information recording portion 12, which comprises a plurality of tracks 13 extending in a longitudinal direction (track direction) of the optical card 11, being parallel to each other. On both sides of the optical information recording portion 12, there are arranged ID portions 14A and 14B, respectively, and an information recording area 15 therebetween. In each ID portion 14A and 14B, address information corresponding to each track 13 is recorded.
In an apparatus by which optical information is recorded and/or reproduced on/from such optical card by moving the optical head and the optical card in a relative and reciprocal manner, the optical card is generally held in a container, which is a so-called shuttle; the shuttle containing the optical card therein is arranged to be relatively moved with respect to the optical head in the track direction; and the optical head is arranged to be relatively moved with respect to the optical card in a direction perpendicular to the track direction (tracking direction). FIG. 2 is a plan view showing the positional relation between the optical head 31 and the shuttle 21 containing the optical card 11 in the apparatus. The arrow A represents the track direction along which the shuttle 21 is relatively moved with respect to the optical head 31, and the arrow B represents the tracking direction, perpendicular to the track direction, along which the optical head 31 is relatively moved with respect to the optical card 21.
In such apparatus for recording/reproducing optical information on/from an optical card, the shuttle is generally driven with the aid of a driving motor, such as a linear motor. When some accident happens in a driving system for moving the shuttle, there is a possibility that the shuttle is moved over its movable limitation. Therefore, when some accident happens in the driving system, an electric supply for the driving motor should be stopped in order to prevent breakage of the linear motor.
In order to solve such problem, in Japanese Utility Model Preliminarily Publication No. 63-81366, is disclosed an apparatus having stoppers on both end portions of a shaft for supporting the optical head. There are provided two electric conductors on the stoppers, respectively, and there are also arranged plastic members having electric conductivity on both ends of the optical head in its moving direction; and the contact of the optical head and the stoppers are detected by a detector, which is arranged to detect the fact that the electric conductors electrically shorten when the optical head makes contact against the stoppers. Further, in Japanese Utility Model Preliminarily Publication No. 63-99367, is disclosed an apparatus having magnetoelectric elements on both end portions of a movable distance of an optical head and plastic magnet members on both end portions of the optical head. Therefore, the fact that the movable body arrived to the end portions of the movable distance thereof is detected with the aid of the magnetoelectric elements. Furthermore, in Japanese Utility Model Preliminary Publication No. 63-109580 is disclosed an apparatus having buffer members having an electric conductivity on both end portions of a movable range of coils of an optical head, and the buffer members are connected to an electric circuit by which an electric supply for the coils is stopped when the optical head has moved over the movable range.
As stated above, in the conventional apparatuses, there are provided limit switches at both end portions of movable range of the movable body, such as optical head, magnetic head and coils provided therein, so as to detect that the movable body has moved to the end portions of the range; and then the electric current supply to the driving motors for driving the movable body is interrupted. However, in the conventional apparatuses, there is a drawback that the construction of the apparatus becomes complex and the cost for manufacturing would increase because the limit switches are arranged only for the purpose of detecting that the movable body has moved to the end portions of the range.
FIG. 3 is a side view showing the positional relation between the optical head 31 and the shuttle 21 containing the optical card 11 therein. The shuttle 21 comprises an auxiliary plate 21a and a press plate 21b which serve to hold the optical card 11 therebetween at a desired position without deviation, a spring 21c for energizing the press plate 21b in an upper direction, and a base plate 21d. The optical card 11 is inserted between the auxiliary plate 21a and the press plate 21b; and the spring 21c is arranged between the press plate 21b and the base plate 21d. The press plate 21b is energized with respect to the auxiliary plate 21a by means of the spring 21c, so that the optical card 11 is contained in the shuttle 21 in a stable manner. The shuttle 21 is reciprocally moved in the track direction by a driving motor (not shown in FIG. 3).
In such conventional apparatus, there is a possibility that when a driving circuit for driving the optical head 31 is damaged, for example, when the optical head 3 is driven over the movable range thereof. As clear from FIG. 3, an objective lens 31d of the optical head 31 is generally positioned in a level lower than the level of the upper surface of the auxiliary plate 21a, due to a working distance of the objective lens 31d. Therefore, when the optical head 31 has been moved over the movable range thereof, the objective lens 31d would collide against the auxiliary plate 21a; and in the worst case the objective lens 31d would be broken so that optical information could not be recorded/reproduced on/from the optical card 11 any more.
In the optical card 11 shown in FIG. 1, there are provided ID portions 14A and 14B on both sides of the optical card 11 in its longitudinal direction; therefore address information of each track recorded thereon can be read out when the optical card 11 is moved with respect to the optical head not only from right to left but also from left to right. That is to say, when optical information is recorded/reproduced by moving the optical card 11 from the left side to the right side in the track direction, the desired track is recognized with the aid of track address information recorded on the left side ID portion 14A; and when optical information is recorded/reproduced by moving the optical card 11 from the right side to the left side the desired track is recognized with the aid of track address information of the right side ID portion 14B. It should be noted that the ID portions 14A and 14B are arranged inside by a given distance from both ends of the optical card 11. The margins outside the ID portions are arranged in order to proof the influence of defect or dirt formed on the edge portions of the optical card 11. The margins are further utilized as an acceleration and deceleration area. That is to say, the moving speed of the optical card 11 is accelerated at one of these areas, at a constant speed between ID portions 14A and 14B and then decelerated at another ID portion.
In the apparatus, in which the optical card 11 is used as an information recording medium, information is recorded on the optical card 11 such that the optical card 11 is reciprocally moved in the track direction between the ID portion 14A and 14B at a constant speed; a clock signal is produced in a clock generating circuit, which is arranged to be independent from the movement of the optical card 11; a light beam emitted form a light source in the optical head 31, which is modulated being synchronized with the clock signal, is made incident upon the optical card 11. While, information is reproduced from the optical card 11 such that, clock signal is produced in accordance with an information reproducing signal obtained by detecting a reflection light beam reflected by the optical card 11; then the information reproducing signal is demodulated being synchronized with the clock signal obtained thereby.
In such an apparatus, it is desired that a variation of the relative moving speed of the optical card 11 and the optical head 31 between the ID portions 14A and 14B be almost zero. However, in order to make such variation zero, it is necessary to control the systems in the apparatus in a very complex manner; and then the cost for manufacturing the apparatus would be increased. Additionally, in the apparatus, the optical card and the optical head should be relatively moved between the ID portions 14A and 14B at a constant speed in order to record/reproduce optical information on/from the optical card in a good manner. Therefore, in the apparatus for the optical card, it is necessary to repeat the following steps that: the optical card 11 and the optical head 31 are started to be moved, the moving speed thereof is increased, decreased, and then stopped. However, in case the optical card is used as a recording medium, it is more difficult to control the relative moving speed of the optical head and the optical card in an exact manner in comparison with the optical disc, in which the optical disc is rotated in a given direction.
When information is reproduced from the optical card 11, the clock signal is produced in accordance with the information reproducing signal, which is obtained from the reflection light beam reflected by the data portion 15 of the optical card 11, and the information reproducing signal is demodulated being synchronized with the thus obtained clock signal. Thus, in case the variation of the relative moving speed of the optical head 31 and the optical card 11 is limited to a range, in which the clock signal can be produced, information could be reproduced without difficulty. However, when information is recorded on the optical card 11, the frequency of the clock signal for recording is not varied in accordance with the variation of the relative movement of the optical head 31 and the optical card 11. Therefore, the variation of the relative movement would make an influence to the information recording effect. If the variation of the relative movement when information is recorded is so large, that the variation of the relative movement when information is reproduced would substantially become large because the variation would be superimposed with the variation of the relative movement caused when information is recorded. Therefore, the information reproducing function of the apparatus would be decreased.
In case the optical card 11 having two ID portions 14A and 14B at both sides thereof as shown in FIG. 1 is used as an information recording medium, when the relative moving speed of the optical card 11 and the optical head 31 under the information recording manner is faster than the desired speed, a margin for the variation of the readable relative moving speed of the optical card and the optical head would be decreased. And in the worst case, ID portions 14A and 14B would be damaged due to the variation.
Even in case an optical card having one ID portion at one side thereof is used as an information recording medium, a margin for the variation of the readable relative moving speed of the optical card and the optical head would be decreased. And in the worst case, ID portions 14A and 14B would be also damaged.
On the other hand, the relative moving speed between the optical card 14 and the optical head 31 is slower than the desired speed, in case the optical card having two ID portions at both sides thereof is used as an information recording medium, the margin for the variation of the readable relative moving speed would be decreased; and in case the optical card having only one ID portion is used, not only the margin for the variation of the readable relative moving speed would be decreased but also the relative moving speed would not be increased upto the desired speed although the optical head is positioned at the information recording area of the optical card, so that the reproduction signal could not be reproduced.

Apparatus for recording and/or reproducing information on/from optical card-like information recording medium


An ankle-foot orthotic device is designed to closely simulate the natural movement of a lower extremity throughout a proper walking gait cycle. The orthotic device includes upper and lower support members that are pivotally coupled by opposing dorsiflexion assist members. The lower support member includes a rigid, unitary cup for receiving the heel and ankle portions of the lower extremity. The cup is shaped to include a continuous slot that allows for at least 5 degrees of compression upon initial heel strike and thereby promotes a smooth, decelerating heel roll. The lower support member additionally includes a rigid footplate on which is mounted a flexible overlay, the overlay extending beyond the footplate in the medial aspect to promote proper pronation into midstance. A compressible stop is mounted on the lower support member and selectively contacts the upper support member to prevent hyperextension of the lower extremity.

An ankle-foot orthosis (also commonly referred to in the art simply as an AFO) is an orthotic device that firmly surrounds at least a portion of the ankle and foot of a patient. An ankle-foot orthosis is commonly constructed as a relatively lightweight and rigid brace that supports the lower leg and foot of a patient and serves to, among other things, properly control the position and motion of the ankle and foot of the patient through each gait cycle, compensate for muscular weakness and/or correct deformities. For this reason, ankle-foot orthotic devices are commonly utilized in the treatment of patients suffering from a wide variety of muscular disorders, such as stroke patients.
One type of ankle-foot orthosis which is well known in the art is constructed as a rigid brace which utilizes a solid ankle design. In other words, the brace includes an enlarged, solid piece of rigid material, such as polypropylene, that wraps around the majority of the foot, ankle and lower leg of the patient. Although useful in providing the patient with the requisite degree of stabilization for adequate weight support, ankle-foot orthotics that rely on a unitary, solid design inherently lack the flexibility to assist the patient to closely simulate the proper gait cycle.
Specifically, a proper gait cycle consists of the events from first heel strike (i.e., contact of the heel onto the ground) to second heel strike on the same foot. In the industry, the gait cycle is commonly separated into two principal phases: (1) the stance phase—the weight bearing portion of the gait cycle (i.e., the period of direct contact of the foot against the ground), and (2) the swing phase—the non-weight bearing portion of the gait cycle (i.e., the period in which the foot swings above the ground, from toe-off to subsequent heel strike). As can be appreciated, 62% of gait is weight-bearing, whereas 38% of gait is non-weight bearing. Accordingly, it is to be understood that proper lower extremity support is essential to a patient with physical limitations.
The stance phase of the proper walking gait cycle includes five defined stages: (1) initial contact—when the heel of the patient first strikes the ground (i.e., initial heel strike), (2) loading response—the period from when weight bears on the loaded extremity after initial contact until the opposite foot is lifted for the swing phase, (3) mid stance—the first half of single limb support from when the opposite foot is lifted until weight is disposed over the fore foot, (4) terminal stance—the period from when heel rises until the opposite foot strikes the ground, and (5) pre swing—the period from when the initial contact of the opposite foot to toe-off on the first foot.
It is to be understood that the lower extremity of a patient includes three natural rockers to assist in the complex kinetic chain required to perform the stance phase. Specifically, the lower extremity includes (1) a heel rocker that acts as a fulcrum as the foot rolls into plantar flexion by allowing the limb to roll forward as body weight is dropped thereon after the initial strike, with pre-tibial muscles decelerating the foot drop and drawing the proximal end of the tibia forward, (2) an ankle rocker that acts as a fulcrum as the tibia moves forward relative to the foot once the forefoot strikes the ground, with tibia progression controlled by eccentric contraction of the soleus muscle in the back part of the lower leg, and (3) a forefoot rocker that acts as a fulcrum as tibial progression advances to toe-off (i.e., as the heel rises, the fulcrum for the tibia as advancement shifts to the metatarsal heads, with progression accelerated as body weight falls beyond the area of foot support).
As referenced briefly above, it is often desirable for an ankle-foot orthosis to closely simulate the proper motion of the treated lower extremity throughout the gait cycle. Because the gait cycle requires a relatively complex kinetic chain of movement in the lower extremity, the majority of which is load-bearing, it is often important that an ankle-foot orthosis be designed to promote the proper sequence of complex movement.
In particular, it has been found that the heel strike is a traumatic event that creates substantial amount of shock, or force, in the heel. However, traditional AFOs that rely upon a solid design fail, among other things, to properly decelerate the heel upon initial heel strike to create a smooth roll and thereby simulate proper movement of the heel rocker. Rather, solid ankle design AFOs tend to throw the weight of the patient forward and/or outward in a rapid manner and without proper control, which is highly undesirable.


A retractable floor cover. The device includes an elongated cylindrical housing and a flexible panel connected to a rotatable spool disposed within an interior volume of the housing, which is operably connected to a spring-rewind mechanism. The panel extends outwardly through a slot disposed on the housing, wherein the panel is configured to move between an extended position and a retracted position. A control disposed on the housing is configured to activate the spring-rewind mechanism, wherein activation of the spring-rewind mechanism is configured to roll the panel along the spool and retract the panel though the slot and into the interior volume of the housing. The housing can be integral to an article of furniture or may be secured to an existing article of furniture via a first strap disposed on a first end of the housing and a second strap disposed on an opposing second end of the housing.

The present invention relates to protective floor covers. More specifically, the present invention provides a retractable floor cover that includes a housing integral or securable to an object such as a furniture leg, wherein the retractable floor cover includes a flexible panel that can be selectively deployed to cover an area of flooring in order to prevent stains or other messes thereon.
Floors within a home or other dwelling often collect dirt, stains, debris, and other undesirable materials. It can be difficult to maintain a clean carpet, hardwood, tile, or other floor surface within a home. Foods, drinks, and other items often accidentally fall to the floor and require immediate cleaning in order to prevent or at least minimize dirtying or staining of the floor surface. If a stained surface is not quickly cleaned, permanent damage may occur to the surface, and such damage may be costly and time consuming to repair. Stained or dirty floors become a greater problem in common areas of the home, such as a living room where individuals often gather for recreation and social interaction, since stains there are more likely to occur due to the accidental spillage of foods, beverages, and the like.
One method of preventing a material from staining a particular floor surface is to cover the floor surface with a pad, plastic cover, or similar floor cover that can receive any potentially staining material. However, such floor covers are often bulky and difficult to handle due to the size of the area to be covered. These types of floor covers typically lack fasteners for securing the cover in place, and as such may be accidentally slid away from the desired area to be covered. Further, typical floor covers for preventing stains can be unappealing looking and detract from the overall aesthetic appeal of the room in which they are present. Therefore, it is desirable to provide a floor cover that can be extended to cover an area of flooring to prevent dirtying or staining thereof, which can also be retracted to a hidden position when the floor cover is not needed.
In light of the devices disclosed in the known art, it is submitted that the present invention substantially diverges in design elements from the prior art and consequently it is clear that there is a need in the art for an improvement to existing floor covering devices. In this regard the present invention substantially fulfills these needs.


In a shifting device, for a power transmission having a sliding sleeve which is arranged on a transmission shaft and which can be brought into operative engagement with at least one corresponding clutch member and which is limited in its sliding movement by at least one stop structure, the stop structure is formed by a component, in relation to which the sliding sleeve, in its striking position, has some freedom of movement to avoid contact between the sleeve and the stop structure.

The invention relates to a shifting device for a motor vehicle transmission having a sliding sleeve which can be operatively engaged with a clutch member.
DE 38 03 845 A1 discloses such a shifting device for a motor vehicle transmission. The shifting device comprises a sliding sleeve which is arranged on a shaft and which can be brought into operative connection with corresponding clutch members. The clutch members have clutch teeth with stops for limiting the axial sliding movement of the sliding sleeve.
It is the object of the present invention to provide a shifting device with relatively little overall space requirements.


A flash memory device includes a data input/output pad and a core region in which a plurality of unit cells are arranged. A data input buffer is configured to receive command and address data through the data input/output pad and transfer the received command and address to the core region. A data output buffer is configured to output the data through the data input/output pad, and a data input controller is configured to detect an outputting of the data and disable the data input buffer.

The present invention relates to a semiconductor memory device, and more particularly, to a data input buffer of a flash memory device.
Semiconductor memory devices are used for storing data. The semiconductor memory devices may be classified by various criteria. As one example, semiconductor memory devices are classified into volatile memory devices and nonvolatile memory devices according to whether they retain data even when power is interrupted. The volatile memory devices retain data when power is being supplied, but their stored data disappear when power is interrupted. Examples of the volatile memory devices include dynamic random access memory (DRAM) and static random access memory (SRAM). On the other hand, the nonvolatile memory devices retain data even when power is interrupted. Examples of the nonvolatile memory devices include mask erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), and flash memory devices. As portability of electronic devices is emphasized, the use of nonvolatile memory devices is further increasing. In particular, flash memory devices among the nonvolatile memory devices are widely used because they can store and read data in a convenient way.
Flash memory devices are generally classified into NAND flash memory devices and NOR flash memory devices. In a NOR flash memory device, one MOS transistor is connected to a word line and a bit line as a unit storage element. Like in a general DRAM, a plurality of bit lines are disposed to cross a plurality of word lines, and a plurality of MOS transistors are disposed at crossing points between the bit lines and the word lines as unit storage elements. In a NAND flash memory device, a plurality of MOS transistors are serially connected to form one string as unit storage elements for high integration. That is, a drain of a MOS transistor is connected to a source of an adjacent MOS transistor. Therefore, the NOR flash memory device has a fast read/write speed, but is disadvantageous in high integration. On the other hand, the NAND flash memory device has a slow read/write speed, but is advantageous in high integration. In recent years, the demand for high-capacity portable memory devices has significantly increased.
A data storing operation of a flash memory device includes a program operation and an erase operation. The program operation is to change a threshold voltage of a MOS transistor used as a unit storage element of the flash memory device, and the erase operation is to restore the change threshold voltage of the MOS transistor. For example, the threshold voltages of the MOS transistors where data "1" will be stored are reduced to a predetermined level, and the threshold voltages of the MOS transistors where data "0" will be stored are maintained as they are.
FIG. 1 is a block diagram illustrating a read operation of a flash memory device. The flash memory device receives a command signal and an address and outputs data through one data input/output (I/O) pad.
Referring to FIG. 1, in the read operation, a read command and an address are sequentially inputted and then data is outputted. An I/O timing of the command, the address, and the data is controlled by control signals ALE, WEB, REB, CLE and R/BB. The command and the address inputted from the outside through one data I/O pad are stored in a data input buffer. The command and the address stored in the data input buffer are transferred to a core region. A data output buffer outputs the stored data through the data I/O pad through which the command and the address have been inputted. Therefore, the data input buffer is always in an enabled state while the read command for outputting the data to the outside is executed. This causes high power consumption in the flash memory device.
FIG. 2 is a block diagram of a conventional flash memory device.
Referring to FIG. 2, the conventional flash memory device includes a data output buffer 10, an input timing controller 20, a data input buffer 30, an electrostatic discharge (ESD) protector 40, and a data input controller 50.
The data output buffer 10 stores data DOUT and outputs the stored data DOUT through a data I/O pad DQ to the outside. The ESD protector 40 protects internal circuits, e.g., the data input buffer 30 and the input timing controller 20, from electrostatic discharge inputted through the data I/O pad DQ. The data input buffer 30 latches data, address, command transferred through the data I/O pad DQ and transfers them to the input timing controller 20 in response to an enable signal EN. The data input controller 50 generates the enable signal EN for controlling an enable timing of the data input buffer 30 in response to control signals STDBY and BYTE. The control signals STDBY and BYTE are activated in a standby mode. The data input controller 50 controls the data input buffer 30 to be disabled in the standby mode. The input timing controller 20 controls setup/hold timing of data, address, and command outputted from the data input buffer 30 and transfers the controlled setup/hold timing to the core region.
FIG. 3 is a circuit diagram of the data input controller 50 illustrated in FIG. 2.
Referring to FIG. 3, the data input controller 50 includes a NAND gate ND1 configured to receive the control signals STDBY and BYTE, and inverters I1 and I2 serially connected to invert an output signal of the NAND gate ND1.
As described above, the data input buffer 30 of the conventional flash memory device is always in the turned-on state all the modes other than the standby mode. Therefore, the conventional flash memory device consumes a large amount of current while the read or write command is executed.

Flash memory device and method for driving the same


A system and method for controlling avoiding collisions and deadlocks in a workcell containing multiple robots automatically determines the potential deadlock conditions and identifies a way to avoid these conditions. Deadlock conditions are eliminated by determining the deadlock-free motion statements prior to execution of the motions that have potential deadlock conditions. This determination of deadlock-free motion statements can be done offline, outside normal execution, or it can be done during normal production execution. If there is sufficient CPU processing time available, the determination during normal production execution provides the most flexibility to respond to dynamic conditions such as changes in I/O timing or the timing of external events or sequences. For minimal CPU impact the determination is done offline where many permutations of programming sequences can be analyzed and an optimized sequence of execution may be found.

Movement of objects in space is a necessary task in a typical manufacturing environment. Robotics have increasingly been employed to effect the necessary movement. However, when multiple objects are being moved, a potential for interference between the objects exists. An interference exists if the at least two objects share the same space at the same time, such as when the objects have the same coordinates with respect to a common frame of reference.
As modern industrial robots move at considerable velocities, interferences between robots can result in a collision and undesirable damage to the robots and work pieces being handled by the robots. The collisions may lead to costly down time in the manufacturing process. Accordingly, it is desirable to avoid such collisions.
Prior art systems and methods have been used in an attempt to minimize interferences and collisions. However, there are several shortcomings of the prior art systems and methods. Typically, a tool center point (TCP) is only checked relative to a predetermined interference area or "static space". For multiple robots, it is difficult to directly or effectively prevent the collision or interference thereof. Further, it is difficult to specify an interference space in respect of a static coordinate system for multiple moving robots. Any interference space is not only a function of the robot motion path, but also a function of the motion speed. Difficulty also exists in attempting to handle a deadlock situation when two or more robots request to move to a common space at the same time.
Prior art systems also attempt to prevent a TCP for a robot from colliding in a fixed space relative to its world coordinate system. When multiple robots (with multiple controllers) share common or "interference" spaces during a task execution, each controller has to wait until no robot is in the common spaces. Then the controller can then issue the motion control commands to allow the robot to move. This process is also called a "wait and move" process, which generally increases working cycle time. However, it is difficult to effectively specify an interference space in terms of a fixed coordinate system, because the interference space is not only the function of the robot motion path but also the motion speed. When more than one robot requests to move to a common space at the same time, it creates a deadlock situation where none of the robots can move because they are waiting for one another.
Prior art systems also attempt to model the robot by spheres and cylinders. These systems predict a future location of the robot during motion in real time. Because these systems do not determine the accumulated space occupied by the robot over time, these systems must perform comparison frequently during the robot motion. These systems compare element by element the models of all robots in the workcell. This comparison is very expensive computationally and the cost grows exponentially as the number of robots and elements used to model a robot and tooling is increased. Since the comparison is done real time when an impending collision is detected these systems generally must stop all robots involved in the impending collision and automatic programmed operation must cease. These systems become more difficult when the robots reside on different controllers because they require large amounts of information to be communicated real-time between controllers. Prior art systems also attempt to utilize I/O handshaking mechanism for interference avoidance. In present invention, there is no need for I/O PLC.
One known system and method is disclosed in Assignee's copending International Application No. PCT/US2007/066638, hereby incorporated herein by reference in its entirety. The system and method includes a "dynamic space check" system wherein an efficiency of robot operation is maximized and a potential for interference or collision of multiple robots is minimized. Robots controlled by each controller only work on a user-defined dynamic space, thus avoiding collision. However, the dynamic space check system generally protects a TCP only against a user-defined rectilinear space.
Another known method for avoiding robot collisions is reported in U.S. Pat. No. 5,150,452 to Pollack et al. The method includes creating a collision map containing a desired robot move. The initial position of the desired robot is removed from a "world" map by combining the robot map and the world map in a logical exclusive-OR operation and thereafter combining the collision map and the world map in a local exclusive-OR operation followed by combining the collision map and the world map in a logical inclusive-OR operation in a byte-by-byte manner. A collision is indicated by a difference in any bit position of the inclusive- and exclusive-OR combinations. The method provides a two dimensional x-y projection and one dimensional height for collision detection, but does not allow for three-dimensional, real time collision detection.
A further known method for detecting a collision between a robot and one or more obstacles before it occurs is described in U.S. Pat. No. 5,347,459 to Greenspan et al. The robot is modeled by spheres in a voxelized workspace. Each voxel within the workspace is assigned a value which corresponds to its distance from the closest obstacle. A collision is determined to be imminent if the voxel value at the center of a sphere is less than the radius of other sphere in voxels. The method merely protects a single robot arm, however. The robot is also modeled by spheres only, thereby resulting in insufficient protection of critical process paths of the robots.
There is a continuing need for a system and method for controlling motion interference avoidance for a plurality of robots. Desirably, the system and method provides a three dimensional and real time collision detection, communication of robotic motions to the robotic system in advance, reservation of programmed trajectories without collision, and protection of critical process paths.
Deadlock conditions occur when the programs or tasks are in such a state that continued sequential execution of any of the programs or tasks will result in interference between one or more robots associated with the programs or tasks and that there is no program or task that can proceed in the sequential manner without interference.
U.S. Pat. No. 7,114,157 to Chaffee et al. describes a method to avoid deadlock by acquiring resources in a set order. While this method can avoid deadlock, it provides no capability of allowing operation if the set deadlock-free order has not been determined. Furthermore, it does not allow operation that may be deadlock-free if the requested order is outside the prescribed deadlock-free order.
U.S. Patent Application Publication No. 2009/0326711 to Chang et al. describes a method of utilizing automatic zones to avoid deadlock either automatically or manually. Chang suggests a method of using priority values to prevent deadlock. Chang does not suggest a method of preventing deadlock where priority values are not used.

Method and system for automatically preventing deadlock in multi-robot systems


To address the need for faster location determination by GPS-equipped units, this application describes embodiments of the present invention that provide GPS-assist data to a remote unit (110) that is determining its location. This GPS assist data is relative to a central point of a grid element that contains the particular remote unit. The grid element is a geographical area within which a predetermined number of GPS satellites are viewable from anywhere within the grid element. By providing GPS-assist data for a grid element, the remote unit receives GPS-assist data sufficiently local in nature to help it determine its location more quickly. Also, because there are significantly fewer grid elements than cell sites over a region such as the US, the maintenance of current GPS-assist data on a grid element basis requires less network bandwidth than it would on a cell site basis.

GPS receivers normally determine their position by computing relative times of arrival of signals transmitted simultaneously from a multiplicity of GPS (i.e., GPS/NAVSTAR) satellites. These satellites transmit, as part of their message, both satellite positioning data and GPS-assist data, such as clock timing or "ephemeris" data. The process of searching for and acquiring GPS signals, reading the ephemeris data for a multiplicity of satellites and computing the location of the receiver from this data is time consuming, often requiring several minutes. In many cases, this lengthy processing time is unacceptable, particularly in emergency situations where location is being determined for a 911 dispatch center.
There are two principal functions of GPS receiving systems: (1) computation of the pseudoranges to the various GPS satellites, and (2) computation of the position of the receiving platform using these pseudoranges and satellite timing and ephemeris data. The pseudoranges are simply the time delays measured between the received signal from each satellite and a local clock. The satellite ephemeris and timing data is extracted from the GPS signal once it is acquired and tracked. As stated above, collecting this information normally takes a relatively long time (30 seconds to several minutes) and must be accomplished with a good received signal level in order to achieve low error rates.
Virtually all known GPS receivers utilize correlation methods to compute pseudo-ranges. These correlation methods are performed in real time, often with hardware correlators. GPS signals contain high rate repetitive signals called pseudorandom (PN) sequences. The code sequences belong to a family known as Gold codes. Each GPS satellite broadcasts a signal with a unique Gold code.
For a signal received from a given GPS satellite, following a down-conversion process to baseband, a correlation processor multiplies the received signal by a stored replica of the appropriate Gold code contained within its local memory, and then integrates, or low-pass filters, the product in order to obtain an indication of the presence of the signal. This process is termed a "correlation" operation. By sequentially adjusting the relative timing of this stored replica relative to the received signal, and observing the correlation output, the receiver can determine the time delay between the received signal and a local clock. The initial determination of the presence of such an output is termed "acquisition." Once acquisition occurs, the process enters the "tracking" phase in which the timing of the local reference is adjusted in small amounts in order to maintain a high correlation output.
The correlation acquisition process is very time consuming, especially if received signals are weak. To improve acquisition time, many GPS receivers utilize many correlators (even thousands potentially) that allow a parallel search for correlation peaks. However, the need to improve location determination time still exists, particularly in the wireless environment with issuance of the E911 regulations by the FCC in the US.

Method and apparatus for determining location of a remote unit using GPS


A fire extinguisher system is provided including a wall mount with an open front. The wall mount is adapted to be situated within an opening formed in a recipient surface such that the open front is in coplanar relationship therewith. Next provided is a housing having a closed front face with an aperture formed therein. A fire extinguisher is provided having an actuation assembly adapted to release the fire extinguishing material upon the detection of a temperature above a predetermined amount. The fire extinguisher is situated within the housing with the actuation assembly protruding from the aperture thereof. During use, the housing may be removably situated within the wall mount with the front face of the housing remaining in coplanar relationship with the open front of the wall mount.

1. Field of the Invention
The present invention relates to fire extinguishers and more particularly pertains to a new self-contained, remote, automated fire suppression system for mounting a self-contained fire extinguisher to a receipt surface such as a wall or ceiling.
2. Description of the Prior Art
The use of fire extinguishers is known in the prior art. More specifically, fire extinguishers heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
Known prior art fire extinguishers include U.S. Pat. No. 5,441,113; U.S. Pat. No. 5,145,014; U.S. Pat. No. 5,127,479; U.S. Pat. No. 5,096,124; U.S. Pat. No. 5,113,945; and U.S. Pat. No. Des 251,464.
In these respects, the self-contained, remote, automated fire suppression system according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of mounting a self-contained fire extinguisher to a receipt surface such as a wall or ceiling.

Self-contained remote automated fire suppression


In a computing system a method and apparatus for cache pooling is introduced. Threads are assigned priorities based on the criticality of their tasks. The most critical threads are assigned to main memory locations such that they are subject to limited or no cache contention. Less critical threads are assigned to main memory locations such that their cache contention with critical threads is minimized or eliminated. Thus, overall system performance is improved, as critical threads execute in a substantially predictable manner.

As the microprocessor industry continues to improve the performance of central processing units (CPUs), more emphasis is being placed on designs supporting greater degrees of parallelism in CPUs, as well as multiple CPUs on a single chip. This emphasis is due to, at least in part, an increased need for thread-level parallelism. As is well known in the art, multiple applications may execute in parallel on a multi-tasking operating system. Furthermore, each of these applications may be further divided into multiple threads of execution. Each thread may be also referred to as a "process" or "task." A highly-parallel system is able to execute potentially many threads concurrently, and thereby improve system performance.
However, threads in such a system may contend for access to memory. Memory in computer systems is typically hierarchical, with small amounts of fast memory located nearby the CPU(s) in a cache, while a larger amount of slower memory is available in main memory (e.g., RAM) and an even larger amount of yet slower memory is available in secondary storage (e.g., a disk drive). A thread may require memory to hold its instructions and data. Instructions are the actual microprocessor codes that a CPU will execute on behalf of a thread. The set of all instructions that comprise an executable program is sometimes referred to as the program's "image." Data is the memory that a thread uses during execution.
Given that a CPU can typically read or write cache memory in a small number of clock cycles, it is desirable to maintain a copy of a thread's instructions and data resident in the cache. However, when the cache is shared between all of the threads that are executing in the system, any one of these threads is unlikely to have all of its instructions or data cache-resident. This can lead to worst-case situations in which each thread that is task-switched into a CPU has no cache-resident instructions or data, because other thread(s) have used all of the available cache lines. The cache then must reload the appropriate instruction and data from slower main memory, which delays execution of the thread. This phenomenon is known as "thrashing" the cache.
In real-time computer systems, such as avionics command and control systems, critical threads may need to execute a certain number of times within a given time frame. When critical threads contend with one another or with other threads for cache space, the overall efficiency of the system is reduced. For example, the system might have to be configured to assume that a worst-case cache delay occurs each time a critical thread is task-switched into a CPU. It is desirable to allow a real-time system to operate correctly on inexpensive, off-the-shelf hardware. However, cache-thrashing of critical threads may result in the system being able to support fewer threads, or the system requiring faster and more expensive hardware.
As is known in the art, the term "CPU" can refer to a single CPU core of a multi-CPU integrated circuit, or die. For purposes of simplicity, the term "CPU" shall include, but not be limited to, a CPU core that may operate in either a single core or a multi-core system.


Provided is a power measurement device including a detection part configured to detect a supply current and a supply voltage from a commercial alternating current power supply, a frequency control part configured to transit a fundamental frequency by the supply current and the supply voltage to an intermediate frequency, a conversion part configured to generate a digital current value and a digital voltage value of the supply current and the supply voltage having the intermediate frequency applied from the frequency control part and transit the intermediate frequency to the fundamental frequency again, and a calculation/control part configured to calculate wattage using the digital current value and the digital voltage value, which are output signals of the conversion part.

1. Field of the Invention
The present invention relates to a power measurement device, and more particularly, to a power measurement device capable of improving measurement precision.
2. Description of the Related Art
In recent times, research on a smart grid technique through fusion of an information communication technique and a power technique is being actively performed. A goal of such a technique is to increase efficiency of a conventional power network through information communication and information technology (IT).
Interworking in the conventional power network is performed through two media such as power supply and information communication between a power provider and users. The power provider checks predicted power requirements of the users in real time through IT to prepare power supply.
In addition, a user can check the amount and charge of power consumed by oneself from the power provider in real time to determine a use pattern. A typical case of the above may be "Parameter" of Google, in which a user can search the amount and charge of currently used power through the Google internet site in real time.
As described above, in order to accomplish a smart grid, smooth information exchange through an information communication network between the power provider and power users is essential.
For this, an electronic power measurement device configured to precisely measure the amount of power consumption and convert it into digital information and a telecommunication technique for transmitting the converted digital information are needed.
Here, most of the power measurement devices are inductive watt-hour meters, and the amount of power consumption is displayed through a rotary analog instrument panel. Since the analog value cannot easily be converted into digital information, information exchange through the information communication network is impossible.
However, the latest electronic power measurement system includes a semiconductor device (integrated circuit) such as an analog-digital converter so that the amount of power consumption is converted into digital information, and the corresponding information can be exchanged through the information communication network connected via an added communication module.