A method for changing a metal body, especially an aluminum alloy body, and, in particular, a method for producing a uniform metal body surface for use in achieving desired light reflectance characteristics and/or other useful attributes. The method comprises (a) preparing a metal body in a first solution by producing a first coating on at least a desired portion thereof with the first coating providing a substantially continuous outer surface on the metal body and (b) treating the metal body to achieve substantial uniformity throughout the desired portion of the metal body. In the treating step, substantially all of the first coating is removed in a second solution. The metal body has a substantially uniform roughened surface after the treating step which is sufficient to substantially optimize diffusive reflectance and reduce spectral reflectance of the metal body surface. The preparing step is preferably accomplished by anodizing. The treating step is preferably accomplished by electroetching, etching, and anodizing in that sequence. The final shade of gray of the second coating after the last anodizing step is determined by the contacting time in the etch step and the voltage or current in the last anodizing step. The invention has many attendant advantages including metal body surfaces that have substantially uniform roughness with the surface texture being reproducible.

In various industries it is necessary to produce a metal body having a surface with uniform roughness characteristics. In construction, architecture and special purpose applications, for example, it is desired that metal bodies used as window and door frames, railings, curtain walls, and light standards, among other things, include decorative and protective coatings having a smooth, flat, low-gloss, enamel-like finishes that do not have a metallic sheen. Such a metallic sheen results from the light reflective characteristics of the surface which are in turn dependent upon the surface's degree of roughness. It is also desirable to produce protective coatings having such finishes that are not only clear and colorless but also in a variety of colors, including white, gray, bronze, black, red and gold. In lithography, it is desirable that metal body surfaces uniformly have a desired degree of roughness to enable ink or other decorative coatings or finishes to adhere to desired portions of the metal body.
One approach to produce metal bodies with protective and decorative coatings for construction, architecture and special purpose applications is to paint the metal body, which hides the metallic appearance of the coating. Painted aluminum, while performing satisfactorily for many years, does not have the service life, especially in outdoor exposure, that anodized aluminum does. Because the appearance of painted aluminum is popular with architects, and because there is a need to have coatings with a longer service life than paints, it is desirable to develop a protective coating that has the appearance of a painted finish but has the long-term protective quality of protective coatings formed by anodizing. As used herein, anodize refers to a process wherein a metal body is electrochemically treated to produce a coating on the metal body's surface.
Another approach to produce protective and decorative coatings is to produce oxidized coatings by anodizing the metal body. The first step in this process is a chemical etch step to roughen the surface of the metal body before the coating is applied. The etch step is commonly done using a solution containing 50 to 60 grams per liter of caustic soda at 55.degree. to 65.degree. C. The metal body is immersed for 10 to 12 minutes in the etch solution during which time aluminum is dissolved from the surface. The etch typically produces a metal body surface with a pit diameter of 5 to 20 microns and a depth less than 1 micron. When the desired amount of aluminum is removed, the metal body is de-smutted, rinsed and anodized to produce the protective and decorative oxide coating.
This approach suffers from a series of problems. First, the etch step provides a metal body surface not uniformly having a desired degree of roughness. The surface often contains defects such as pit defects, plateau defects, and die lines which cause complications in later process steps. As a consequence, the light reflective characteristics of the metal body surface give the surface a metallic sheen. Second, the processes provide metal bodies with surface roughnesses that are difficult to reproduce. Accordingly in manufacturing operations, the final products do not have uniform color characteristics. Third, the processes require high current densities and voltages. The processes also require temperatures of the electrolytic bath that are so low that they typically require chilling of the bath. Accordingly, the coatings are expensive to produce.
There are numerous processes to provide oxide coatings in desired colors. One process is disclosed in U.S. Pat. No. 3,031,387 to Deal et al., U.S. Pat. No. 3,328,274 to Bushey et al., and United Kingdom Patent No. 1,344,192. U.S. Pat. No. 3,031,387 discloses a process in which the metal body is chemically etched in a sodium hydroxide and sodium fluoride solution and subsequently anodized in an electrolyte consisting of sulfosalicylic acid and at least one substance selected from the group consisting of metal sulfates and sulfuric acid. U.S. Pat. No. 3,328,274 discloses a process in which the metal body is anodized under constant current density and then, when a certain pre-selected voltage is reached, under constant voltage. United Kingdom 1,344,192 discloses a process to control the color of the coating by developing a voltage-time relationship for a given bath composition and temperature and for a particular metal body composition. These processes produce coatings in a variety of colors including gray, bronze, and black. The processes not only require high power requirements but also are extremely sensitive to the composition of the metal body.
Another process uses an oxalic acid solution containing dissolved titanium in the electrolysis step to produce a white coating. Although the coatings produced by this process are white and opaque, the anodizing bath is difficult to maintain and the process hard to control. Consequently, the coatings are not only expensive to produce but also do not uniformly have desired color characteristics. This lack of uniformity exists not only for a given metal body but also among a series of metal bodies subjected to the process.
The lithographic industry by contrast employs an electroetch step and an etch step to provide a roughened metal body surface. U.S. Pat. No. 3,963,594, for example, discloses a process in which aluminum bodies are electrolytically treated under alternating current in an aqueous solution of hydrochloric acid and gluconic acid. The aluminum bodies are thereafter etched in a sodium hydroxide solution at room temperature. Similarly, United Kingdom Patent 1,027,695 discloses a process in which the electroetch step is followed by a brief electrolysis step under direct current to apply a coating to the aluminum body typically having a thickness of from 1 to 2 microns.
These processes also suffer from a series of drawbacks. First, the combined electroetch and etch steps provide a metal body surface not having a uniform degree of roughness. The surface often contains defects which cause complications in later processing. Second, the processes provide metal bodies with surface roughnesses that are difficult to reproduce. Accordingly in manufacturing operations, the final products do not have uniform roughness characteristics.
In view of the above, a need exists for a new method for providing metal bodies having surfaces with a uniform degree of roughness, for the reproducing such surface characteristics, and producing protective and decorative coatings of different colors that have smooth, flat, lowgloss, enamel-like finishes.

chlorobenzene (major peak),? -? chlorobenzoquinone, chloro-(1,2)-benzenediol (major peak),? -? chloro-(1,3)-benzenediol (major peak), 1,2-benzenediol,? -? 1,3-benzenediol, benzoquinone, ethenylbenzene,? -? 2-methyl-2-pentenal.


A portable audio/video device disposing structure includes: a base having a recession disposed on a surface of the base; a carrying unit movably coupled with the recession of the base and having a disposing portion disposed on a surface of the carrying unit, a latch element disposed at an end of the disposing portion, and an indentation disposed on both sides of the disposing portion separately; and a contractible unit with both ends coupled to the base and the carrying unit respectively. The portable audio/video device is installed on the carrying unit in conformity with the base and the contractible unit to achieve the effects of adjusting the portable audio/video device to any angle and disposing the portable audio/video device in any position.

In general, a portable audio/video device includes a casing, a system processing means, and a storage means, wherein a power supply means, a display screen and a plurality of control keys are coupled to the system processing means separately, and the display screen and the plurality of control keys are installed on a surface of the casing, and thus the audio/video device can be carried easily by users to give an effect of an instant audio/video play.
Although the portable audio/video device emphasizes on the audio/video playing functions, the portability of a light, thin, short and compact device is also very important. Since the portable audio/video device does not come with any support structure, therefore a user has to hold the portable audio/video device to view video contents. Such arrangement not only causes inconvenience to the user's viewing, but also results in pains and uneasiness of the user's hand after holding the portable audio/video device for a long time. Obviously, the aforementioned conventional portable audio/video device is unable to meet the requirements of a practical application.

Portable audio/video playing device disposing structure


A field-effect transistor with improved moisture resistance without an increase in gate capacitance, and a method of manufacturing the field-effect transistor are provided. The field-effect transistor includes: a T-shaped gate electrode on a semiconductor layer; and a first highly moisture-resistant protective film including one of an insulating film and an organic film having high etching resistance, the first highly moisture-resistant protective film being located above the T-shaped gate electrode, over all of a region in which the T-shaped gate electrode is located. A cavity is located between the semiconductor layer and the first highly moisture-resistant protective film, below a canopy of the T-shaped gate electrode. An end surface of the cavity is closed by a second highly moisture-resistant film.

1. Field of the Invention
The present invention relates to a field-effect transistor and a method of manufacturing the field-effect transistor, and more particularly, to a field-effect transistor containing gallium arsenide (GaAs) or gallium nitride (GaN) as a main component, which is suitable for use in a microwave band and a millimeter wave band of several GHz or more, and a method of manufacturing the field-effect transistor.
2. Description of the Related Art
Wireless communication markets using a microwave band and a millimeter wave band are expanding along with the diffusion of satellite communications, high-speed and large-capacity communication systems of a 60 GHz band, on-vehicle radar systems of a 70 to 80 GHz band, and the like. For a transmitting/receiving portion of a signal in those high frequency bands, a field-effect transistor (hereinafter, referred to as FET) such as a metal semiconductor FET (MESFET), a heterostructure FET (HFET), or a high electron mobility transistor (HEMT), which is obtained by lamination on a compound semiconductor epitaxial layer substrate formed of a compound semiconductor, in particular, GaAs or GaN, is mainly used.
In order to achieve cost reduction of transmitting/receiving devices, which is requisite for expanding the wireless communication markets, it is effective to change a hermetically sealed package for a non-hermetically sealed type or a mold sealed type. Meanwhile, a field-effect transistor using the compound semiconductor is generally vulnerable to moisture, and is required to attain high moisture resistance of a chip itself.
In order to enhance moisture resistance, there is an effective measure in which a moisture-resistant protective film is laminated on a surface of a semiconductor to thereby prevent moisture from reaching the surface of the semiconductor. However, in general, the covering by the moisture-resistant protective film accompanies deterioration of transistor characteristics. In a case of the field-effect transistor, an insulating protective film is interposed in a space between a gate electrode and the surface of the semiconductor or between the gate electrode and source and drain electrodes, and therefore a gate capacitance is increased, with the result that the device characteristics are deteriorated.
In general, a FET for a high-power amplifier often adopts a T-shaped gate structure which is effective in reducing a gate resistance. In the T-shaped gate structure, a cavity is formed between a portion below a canopy of the gate and a semiconductor layer. When the cavity below the canopy is filled by lamination of an insulating protective film, the above-mentioned gate capacitance is further increased, and gain characteristics in the micro wave and the millimeter wave are reduced.
An attempt to simultaneously achieve protection of a highly-moisture-resistant film and suppression of an increase in gate capacitance is proposed in JP 2008-98400 A, for example. In the field-effect transistor described in JP 2008-98400 A, the increase in gate capacitance is suppressed by forming the cavity below the canopy of the T-shaped gate.
In JP 2008-98400 A, the increase in gate capacitance is suppressed by forming the cavity below the canopy of the T-shaped gate. However, forming the cavity only below the canopy of the T-shaped gate cannot eliminate a constant increase in gate capacitance due to the highly-moisture-resistant insulating film deposited outside the canopy of the T-shaped gate. As a result, there arises a problem that a gain reduction is caused.
Table 1 below shows results of a gain (MSG) evaluated at 10 GHz in three types of GaAs-pHEMT structures. In a transistor structure with a cavity below a canopy of a gate, the gain is increased by about 0.5 dB compared with a structure in which a portion below the canopy is filled, whereas the gain is decreased by about 0.6 dB to 0.7 dB compared with a transistor without a highly-moisture-resistant film.
TABLE 1GaAs-pHEMT structure: Comparison of gain (MSG) at 10 GHzStructure in which aportion below aInsulating filmcanopy is filledprotection structurewith an insulatingwith a cavity below aStructure without afilmcanopyprotective film14.5 dB15.0 dB15.65 dB

Field-effect transistor and method of manufacturing the same


The present invention relates to a wireless power transmission method for preventing frequency interference, and more particularly, to a wireless power transmitter and a wireless power transmission method for preventing frequency interference that flexibly controls an operation of the wireless power transmitter in order to avoid signal interference and collision between different apparatuses using frequencies adjacent to a frequency band of a power signal transmitted from the wireless power transmitter.

1. Field of the Invention
The present invention relates to a wireless power transmission method for preventing frequency interference, and more particularly to a wireless power transmitter and a wireless power transmission method for preventing frequency interference that flexibly controls an operation of the wireless power transmitter in order to avoid signal interference and collision between different apparatuses using frequencies adjacent to a frequency band of a power signal transmitted from the wireless power transmitter.
2. Description of the Related Art
In general, a wireless power transmission system is used as a technology for transmitting power between apparatuses spaced apart from each other by using an induced electromotive force mechanism. The wireless power transmission system enables power transmission between apparatuses placed at separated positions by using a predetermined range of frequency (in general, a frequency in the range of 100 to 210 Khz) and since the wireless power transmission system transmits power by using a wireless signal, if a signal for transmitting power is close to another apparatus using a frequency adjacent to a used frequency band, there is a possibility that malfunction will occur due to frequency interference.
Therefore, in order to avoid frequency inference and collision, a multichannel technology is generally used. However, in the wireless power transmission field, a frequency band which can be practically used is extremely limited. Therefore, there is a disadvantage in that changing and using the frequency variously is limited in order to transmit power wirelessly. Further, if the frequency is changed, power transmission efficiency is consequently varied with the change of the used frequency and the variation range is significantly large, such that it is practically difficult to apply the frequency.
In addition, as another method, a method of shielding electromagnetic waves is used in order to reduce a physical area influenced by the electromagnetic waves for the purpose of preventing frequency interference between different apparatuses. However, this method has a disadvantage in that an additional cost is generated because a shielding member needs to be additionally installed in order to apply an electromagnetic wave shielding structure and if the design of a wireless power transmission structure needs to be changed, this method has another disadvantage in that a shielding structure applied before the design change needs to be redesigned by remeasuring a radiation pattern whenever the design of the wireless power transmitter is changed. Therefore, there is disadvantage in that the method using the electromagnetic wave shielding is complicated to develop and takes a long time to develop.

Wireless power transmission method for preventing frequency interference


A method for fabricating a multi-layered wafer includes depositing a metal liner following by a seed layer including a metal in a trench arranged in an inter-metal dielectric (IMD). An end of the trench contacts a metal via of an interconnect structure. Heat is applied to drive the metal of the seed layer into the IMD and form a barrier layer along a sidewall of the trench.

The present invention generally relates to fabrication methods and resulting structures for semiconductor devices. More specifically, the present invention relates to methods and resulting structures for integrated circuits (ICs) having a single damascene wiring network.
Generally, integrated circuits (ICs) include a plurality of semiconductor-based circuit elements (or semiconductor devices) communicatively coupled to one another and fabricated on a semiconductor substrate. A complex network of signal paths is routed to connect the circuit elements distributed on the surface of the substrate. To efficiently route these signals across the device, multilevel or multilayered schemes are used, for example, single or dual damascene wiring structures.
To form damascene wiring structures, an insulating layer is patterned with open trenches; a metal, such as copper or cobalt, is deposited in the trenches; and chemical-mechanical planarization (CMP) is used to remove the metal that extends above the top of the insulating layer. In single damascene structures, a single feature is filled with metal per stage, and in dual damascene structures, two features, e.g., a trench overlying a via, are filled with a single metal deposition step.

Integrated circuit having a single damascene wiring network

INTERNATIONAL BUSINESS MACHINES CORPORATION


Provided is a fuel cell comprising a first compartment, a second compartment and a barrier separating the first and second compartments, wherein the barrier comprises a proton transporting moiety.

The present invention relates to batteries, including fuel cells and re-chargeable fuel cells, for use in powering electrical devices.
Batteries such as fuel cells are useful for the direct conversion of chemical energy into electrical energy. Fuel cells are typically made up of three chambers separated by two porous electrodes. A fuel chamber serves to introduce a fuel, typically hydrogen gas, which can be generated in situ by xe2x80x9creformingxe2x80x9d hydrocarbons such as methane with steam, so that the hydrogen contacts H2O at the first electrode, where, when a circuit is formed between the electrodes, a reaction producing electrons and hydronium (H3O+) ions is catalyzed.
2H2O+H22H3O++2exe2x88x92xe2x80x83xe2x80x83(1)
A central chamber can comprise an electrolyte. The central chamber acts to convey hydronium ions from the first electrode to the second electrode. The second electrode provides an interface with a recipient molecule, typically oxygen, found in the third chamber. The recipient molecule receives the electrons conveyed by the circuit.
2H3O++1/2O2+2exe2x88x923H2Oxe2x80x83xe2x80x83(2)
The electrolyte element of the fuel cell can be, for example, a conductive polymer material such as a hydrated polymer containing sulfonic acid groups on perfluoroethylene side chains on a perfluoroethylene backbone such as Nafion(trademark) (du Pont de Nemours, Wilmington, Del.) or like polymers available from Dow Chemical Co., Midland, Mich. Other electrolytes include alkaline solutions (such as 35 wt %, 50 wt % or 85 wt % KOH), acid solutions (such as concentrated phosphoric acid), molten electrolytes (such as molten metal carbonate), and solid electrolytes (such as solid oxides such as yttria (Y2O3)-stabilized zirconia (ZrO2)). Liquid electrolytes are often retained in a porous matrix. Such fuel cells are described, for example, in xe2x80x9cFuel Cells,xe2x80x9d Kirk-Othmer Encyclopedia of Chemical Technology, Fourth Edition, Vol. 11, pp. 1098-1121.
These types of fuel cells typically operate at temperatures from about 80xc2x0 C. to about 1,000xc2x0 C. The shortcomings of the technology include short operational lifetimes due to catalyst poisoning from contaminants, high initial costs, and the practical restrictions on devices that operate at relatively high to extremely high temperatures.
The present invention provides a fuel cell technology that employs molecules used in biological processes to create fuel cells that operate at moderate temperatures and without the presence of harsh chemicals maintained at high temperatures, which can lead to corrosion of the cell components. While the fuel used in the fuel cells of the invention are more complex, they are readily available and suitably priced for a number of applications, such as power supplies for mobile computing or telephone devices. It is anticipated that fuel cells of the invention can be configured such that a 300 cc cell has a capacity of as much as 80 Wxc2x7hxe2x80x94and thus can have more capacity than a comparably sized battery for a laptop computerxe2x80x94and that such cells could have still greater capacity. Thus, it is believed that the fuel cells of the invention can be used to increase capacity, and/or decrease size and/or weight. Moreover, the compact, inert energy sources of the invention can be used to provide short duration electrical output. Since the materials retained within the fuel cells are non-corrosive and typically not otherwise hazardous, it is practical to recharge the fuel cells with fuel, with the recharging done by the consumer or through a service such as a mail order service.
Moreover, in certain aspects, the invention provides fuel cells that use active transport of protons to increase sustainable efficiency. Fuel cells of the invention can also be electrically re-charged.
In one aspect, the invention provides a fuel cell comprising a first compartment, a second compartment and a barrier separating the first and second compartments, wherein the barrier comprises a proton transporting moiety.
In another aspect, the invention provides a fuel cell a first compartment; a second compartment; a barrier separating the first compartment from the second compartment; a first electrode; a second electrode; a redox enzyme in the first compartment in communication with the first electrode to receive electrons therefrom, the redox enzyme incorporated in a lipid composition; an electron carrier in the first compartment in chemical communication with the redox enzyme; and an electron receiving composition in the second compartment in chemical communication with the second electrode, wherein, in operation, an electrical current flows along a conductive pathway formed between the first electrode and the second electrode.


An apparatus, a method, and a computer program product are provided. The apparatus may be an electronic component. The electronic component includes at least one energy harvester coupled between at least one pair of hot and cold regions of the electronic component and configured to convert thermal energy to electrical energy in order to provide power to at least the electronic component, the at least one energy harvester including a radiative thermal channel or a conductive thermal channel. A first end of the conductive thermal channel is coupled to a first semiconductor material and a second end of the conductive thermal channel is coupled to a second semiconductor material, the first semiconductor material being coupled to the hot region and isolated from the cold region and the second semiconductor material being coupled to the cold region and isolated from the hot region.

1. Field
The present disclosure relates generally to harvesting energy, and more particularly, to an apparatus and method for harvesting energy in an electronic device.
2. Background
Mobile electronic devices generally use a battery, which can typically supply power for only a few hours at a time based on the capacity of the battery and the usage of the mobile electronic device. Accordingly, there has been a substantial effort toward the development of techniques for reducing power consumption of the electronic components in the mobile electronic devices. However, as the demand for performance from the electronic components in such mobile electronic devices continues to increase, a substantial amount of thermal energy, i.e., heat, is generated by the electronic components despite the techniques for reducing power consumption.
For example, there is an increasing demand for advanced features and performance in specific areas, such as modems, multimedia, and high speed serial interfaces. To support such advanced features, mobile, applications, media, and modem processor integrated circuits (ICs) are now being designed to include multiple central processing unit (CPU) cores. For example, the power consumption of a Krait CPU core is estimated at 1 watt (W). For quad Krait CPU cores, the estimated power consumption will increase linearly to 4 W if used concurrently. A substantial amount of resources have been allocated to reduce or minimize thermal impacts that may result from the increase of device temperatures as operating power consumption increases.
However, if such thermal energy generated by an electronic component may be converted to electrical energy, the mobile electronic devices will be able to support more advanced features and longer standby times. In addition, engineering efforts for reducing power consumption of the electronic components in the mobile electronic devices may be directed toward other areas in need of development.

Apparatus and method for harvesting energy in an electronic device


The present invention is directed to a method for removal by oxidation of the excess ammonia (NH3) gas (“ammonia slip”) resulting from flue gases that have been subjected to selective catalytic reduction (SCR) for reduction of nitrogen oxides (NOx) with ammonia. More specifically, the inventive method uses an ammonia oxidation catalyst consisting of a zeolite, one or more precious metals, and a base metal compound, to catalyze the oxidation of both ammonia and carbon monoxide (CO), while minimizing the formation of nitrogen oxides (NOx). The present invention is useful in treating flue and exhaust gases.

Much of the electrical power used in homes and businesses throughout the world is produced in power plants that burn a fossil fuel (i.e. coal, oil, or gas) in a boiler. The resulting hot exhaust gas (also sometimes termed "flue gas") turns a gas turbine or boils water to produce steam, which turns a steam turbine, and the turbine cooperates with a generator to produce electrical power. The flue gas stream is subsequently passed through an air preheater, such as a rotating wheel heat exchanger that transfers heat from the flue gas to an incoming air stream, which thereafter flows to the combustor. The partially cooled flue gas is directed from the air preheater to the exhaust stack.
The flue gas contains contaminants such as sulfur oxides (SOx), nitrogen oxide (NOx), carbon monoxide (CO) and particulates of soot when coal is used as the primary fuel source. The discharge of all of these contaminates into the atmosphere is subject to federal and local regulations, which greatly restrict the levels of these flue gas components.
To meet the reduced levels of NOx emissions from power stations, as required by environmental regulations, many fossil fuel-fired electric generating units are being equipped with either selective catalytic reduction (SCR) or selective non-catalytic reduction (SNCR) technologies. In SCR, the most common method used is to inject ammonia or urea based reagents in the presence of a vanadium oxide catalyst where the ammonia reacts to reduce the oxides of nitrogen. SCR is generally accomplished at lower temperatures than SNCR. The SCR system typically operates at flue gas temperatures ranging between 300° C. and 450° C. U.S. Pat. No. 5,104,629 illustrates one known type of SCR installation.
In SNCR, the most common method used is to inject ammonia or urea based reagents into the upper furnace to reduce the oxides of nitrogen without the use of a catalyst. The SNCR system operates at flue gas temperatures ranging between 850° C. and 1150° C. U.S. Pat. Nos. 3,900,554, 4,208,386, and 4,325,924 illustrate known types of SNCR applications.
At coal-fired power plants, ammonia injection systems for SCR and SNCR systems are typically installed in the high-temperature and high-dust region of the flue gas stream, which typically is prior to ash collection. One common problem with the SCR and SNCR technologies is that some residual ammonia, known as ammonia slip, negatively impacts downstream components and processes such as: air pre-heater fouling, fly ash contamination, and ammonia gas emission into the atmosphere. The ammonia slip problem is further exacerbated as the result of SCR catalyst surface deterioration as well as misdistribution in flue gas velocity, temperature, and concentrations of ammonia and NOx.
An additional problem with the current methods is that increased ammonia injections will more efficiently remove the oxides of nitrogen, but then the excess ammonia will result in increased ammonia slip in the flue gas. In coal-fired power plants this excess ammonia can, in addition, contaminate the resulting coal based fly ash.
Even in power plants that are based on natural gas or oil, the environmental effects of the exhausted ammonia is undesirable. The EPA has enacted a variety of regulatory initiatives aimed at reducing NOx. It was determined that the combustion of fossil fuels is the major source of NOx emissions. These control regulations were established by the EPA under Title IV of the Clean Air Act Amendments of 1990 (CAAA90). In July 1997 the EPA proposed another change in the New Source Performance Standards and these revisions were based on the performance that can be achieved by SCR technology.
As briefly described above, the treatment of exhaust gases from boilers and the like presents the following disadvantages:
(1) that some ammonia is left unremoved in the treated gas;
(2) low NOx decomposition rate; and
(3) large ammonia consumption.
The disadvantages (1) and (2) are correlated.
For example, if the ammonia supply is increased in order to raise the NOx decomposition rate, the proportion of residual ammonia in the treated gas will be high. This residual ammonia may exceed the amounts that are permitted by existing regulations to pass into the atmosphere. Thus, the nitrogen oxide separation efficiency of the known processes is limited by the amount of unreacted ammonia that can be discharged into the atmosphere.
Besides, variation in the load on the combustion equipment will change the temperature, at the point where ammonia is introduced, to a value deviated from the optimum temperature range, and this in turn will decrease the decomposition rate, tending to increase the proportion of residual ammonia. Even in a small proportion, the residual ammonia will react rapidly with the sulfuric acid content of the exhaust gas to produce acid ammonium sulfate. This product will stick to the rear heat-transfer surface in the relatively low-temperature region, for example, to the heating surfaces of the air preheater and associated parts of a boiler, causing an increase in pressure loss, hampering the operation of the combustion equipment, and attacking the materials of the equipment for their eventual corrosion.
As described above, the ammonia left unremoved in the treated exhaust gas provides a major obstacle in the way to practical operation. Consequently, there is an upper limit to the ammonia supply and naturally the NOx decomposition rate is low. This has been a problem in the practice of high-temperature noncatalytic denitrification. Furthermore, ammonia, which is introduced in the high-temperature region, undergoes a concomitant reaction for decomposing itself, resulting in the disadvantage (3) of excess consumption of ammonia, or more than the equivalent for the NOx-decomposing reaction. This tendency will be pronounced as the amount of ammonia injection is increased in anticipation of an enhanced decomposition rate. This has been another limiting factor for the rate of NOx decomposition to be attained conventionally.
It is important to accomplish the reaction of the ammonia and NOx in an efficient manner, for maximum possible reaction of both the NOx and the ammonia. If the reaction is incomplete, either NOx or ammonia (or both) may pass through to the stack and be emitted to the atmosphere. Both NOx and ammonia are classified as pollutants, and their emission is to be maintained within legal limits. Furthermore, depending upon the temperature at the cold end of the air preheater, excess ammonia slip may cause clogging of the space between adjacent air preheater heating elements because of the formation of ammonium sulfate/bisulfate, and/or agglomerated fly ash. This results in increased pressure loss of the heat exchanger, corrosion of the apparatus, and therefore unstable operation for a prolonged period and other disadvantages.
In addition, many coal-fired power plants dispose of the collected fly ash by selling it to purchasers who further process the fly ash for commercial uses (i.e. lightweight aggregate for concrete mixtures). Fly ash produced at coal-fired power plants is commonly used in concrete applications as a pozzolanic admixture and for partial replacement for cement. Fly ash consists of alumino-silicate glass that reacts under the high alkaline condition of concrete and mortar to form additional cementitious compounds. Fly ash is an essential component in high performance concrete. Fly ash contributes many beneficial characteristics to concrete including increased density and long-term strength, decreased permeability and improved durability to chemical attack. Also, fly ash improves the workability of fresh concrete.
When ammonia contaminated fly ash is used in Portland cement based mortar and concrete applications, the ammonium salts dissolve in water to form NH4+. Under the high pH (pH>12) condition created by cement alkali, ammonium cations (NH4+) are converted to dissolved ammonia gas (NH3). Ammonia gas evolves from the fresh mortar or concrete mix into the air exposing concrete workers. The rate of ammonia gas evolution depends on ammonia concentration, mixing intensity, exposed surface area, and ambient temperature. While it is believed that the ammonia that evolves has no measurable effect on concrete quality (strength, permeability, etc.), the ammonia gas can range from mildly unpleasant to a potential health hazard. The human nose detects ammonia odors at levels of 5 to 10 ppm. The OSHA threshold and permissible limits are set at 25 and 35 ppm for Time-Weighted Average (TWA) (8-hr) and Short-Term Exposure Limit (STEL) (15-min), respectively. Ammonia gas concentration between 150 and 200 ppm can create a general discomfort. At concentrations between 400 and 700 ppm, ammonia gas can cause pronounced irritation. At 500 ppm, ammonia gas is immediately dangerous to health. At 2,000 ppm, death can occur within minutes.
Other than OSHA exposure limits, there are no current regulatory, industry or ASTM standards or guidelines for acceptable levels of ammonia in fly ash. However, based on industry experience, fly ash with ammonia concentration at less than 100 mg/kg does not appear to produce a noticeable odor in Ready-Mix concrete. Depending on site and weather conditions, fly ash with ammonia concentration ranging between 100 and 200 mg/kg may result in unpleasant or unsafe concrete placement and finishing work environment. Fly ash with ammonia concentration exceeding 200 mg/kg would produce unacceptable odor when used in Ready-Mixed concrete applications.
In addition to the risk of human exposure to ammonia gas evolving from concrete produced using ammonia laden ash, the disposal of ammonia laden ash in landfills and ponds at coal burning power stations could also create potential risks to humans and the environment. Ammonium salt compounds in fly ash are extremely soluble. Upon contact with water, the ammonium salts leach into the water and could be carried to ground water and nearby rivers and streams causing potential environmental damage such as ground water contamination, fish kill and eutrophication. Ammonia gas could also evolve upon wetting of alkaline fly ashes, such as those generated from the combustion of western sub-bituminous coal. Water conditioning and wet disposal of alkaline fly ashes would expose power plant workers to ammonia gas.
U.S. Pat. No. 5,233,934 to Krigmont et al. discloses a control method of reducing NOx in flue gas streams utilizing an SNCR treatment followed by an SCR treatment. The Krigmont et al. method tries to maximize the NOx removal in the SNCR stage, subject to certain ammonia slip restrictions, and injecting additional ammonia for the SCR stage.
U.S. Pat. No. 5,510,092 to Mansour et al. discloses a combined SNCR/SCR process in which SCR is employed for primary NOx reduction and NH3 is injected into the SNCR zone only when the NOx content of the SCR effluent exceeds a pre-selected design maximum value.
U.S. Patent Application Publication No. 2003/0202927 to Minkara et al. discloses a process to reduce ammonia concentration and emissions from both coal-fired plants and plants that use other hydrocarbon fuels. The process in the Minkara et al. application adds an ammonia oxidation catalyst, specifically manganese dioxide, downstream of the SCR system to remove the undesirable ammonia slip by reacting the ammonia with the residual oxygen present in the flue gas.
U.S. Patent Application Publication No. 2006/0182672 to Tran et al. discloses a process that removes by oxidation the excess ammonia gas from flue gases that have been subjected to SCR using a secondary catalyst located downstream of the SCR system. According to Tran et al. the secondary catalyst comprises a precious metal and vanadia on a metal oxide such as titania.
As discussed above, for SCR of oxides of nitrogen with ammonia to work well and result in the lowest values of NOx, it is preferable to be able to use excess ammonia. However, when the quantity of ammonia used is high enough to effectively remove the NOx through SCR, some of the excess ammonia will go through the catalyst unchanged and exit as ammonia slip in the flue gases creating the problem of a toxic reactive gas in the exiting gases. Another major problem created by the excess ammonia exiting in the flue gases, particularly from coal-fired plants, is that the ammonia contaminates the fly ash that is intended for use in mixtures with cement to make concrete. Thus, a need exists for a safe and efficient method for minimizing ammonia slip downstream from the primary SCR catalyst. To keep ammonia emissions low, an oxidation catalyst may be utilized downstream to convert ammonia "slip" to N2. Unfortunately, conventional oxidation catalyst not only catalyze NH3 to N2 reactions but also NH3 to NO. Accordingly, it has been a long-standing challenge in the art to find an oxidation catalyst that selectively and efficiently catalyzes NH3 to N2.

Ammonia oxidation catalyst for power utilities


In a pressure control valve, a filter member is disposed in a feedback path for feeding back fluid pressure in the corresponding control port to a pilot chamber for feedback controlling a position of the valve spool in cooperation with an electric or electromagnetic actuator. The filter member is so arranged as to remove foreign matter. The filter member also serves for regulating fluid flow in the feedback path.

1. Field of the Invention
The present invention relates generally to a pressure control circuit for a hydraulic circuit for controlling discharge pressure for a pair of hydraulic loads. More specifically, the invention relates to a pressure control valve which successfully prevent foreign matters which may cause blocking of a hydraulic circuit and/or hydraulic load from flowing into the hydraulic load. The present invention also relates to a technology for ventilating air introduced into the hydraulic circuit and minimizing effect of a residual air in the hydraulic circuit for damping vibration of valve spool.
2. Description of the Background Art
Pressure control valves have been employed in various hydraulic circuits for controlling hydraulic pressure distribution for loads. For example, one of typical construction of pressure control valves can be seen in "Uchida Lexloss direct type electromagnetic proportioning valve" shown in its catalog, May, 1986, published by K. K. Silver Design.
The conventionally proposed pressure control valve defines an induction port, a drain port, a first control port and a second control port, which ports are communicated with a valve bore defined in a valve body. A valve spool is thrustingly disposed within the valve bore for distributing working fluid introduced through the induction port to the first and second control ports. The valve spool is loaded by a pair of bias springs so as to be biased toward a neutral position. A pair of electrically or electromagnetically operable actuators are provided for driving the valve spool for causing an axial shift for controlling distribution of the working fluid to the first and second control ports.
Control current to be applied to the actuators is so controlled as to cause axial shifting of the valve spool for adjusting distribution of the pressure for the first and second control ports in an inversely proportional fashion. During pressure distribution control in such pressure control valve, control pressure to be supplied to respective loads by way of the first and second control ports varies according to non-linear characteristics in a second order curve. These variation characteristics of the control pressure are caused by a simultaneous variation of path areas at an introduction side and a drain side. Therefore, in case that a load is an actuator, activity of the actuator varies as a second order function of the valve spool stroke. This makes control of the actuator by supplying the control pressure difficult in that requiring a complex arithmetic operation becomes necessary. Particularly, at the valve spool position in the vicinity of a completely shutting position a variation of control pressure versus the valve spool stroke becomes substantial to cause an impulsive change in the actuator.
Furthermore, foreign matter may contained in the working fluid to circulate therewith through the hydraulic circuit and through small gaps defined between components of the pressure control valve assembly. Such foreign matter tends to enter into the small gaps between the components for providing resistance against movement of the components. For example, when the pressure control valve is provided a pilot piston for adjusting pilot pressure in the pressure control valve for determining the valve spool position so that the pilot pressure is cooperating with the mechanical spring force and the force exerted on the valve spool by means of an electromagnetic actuator are to be balanced, the foreign matter entering the small gap prevents the pilot valve from shifting smoothly to cause degradation of response characteristics.
Additionally, as can be appreciated, residual air in the hydraulic circuit often affects for performance of the pressure control valve. Particularly, when dither current is superimposed on a control current supplied to an elecromagnetic actuators so as to minimize resistance of movement of a valve spool, vibration of the valve spool caused by dither current tends to amplify noise when residual air is present in the hydraulic circuit or in the pressure control valve. Removal or ventilation of the residual air in the pressure control valve has been typically performed by removing a closure plug in a ventilation path. This process is cumbersome. In addition, a difficulty is encountered in removing the air when the air resides in the orientation remote from the ventilating opening of the ventilation path.

Pressure control valve assembly for hydraulic circuit and automotive rear wheel steering system utilizing the same


A medicine dispenser for allowing first and second medicine doses to be safely dispensed. The medicine dispenser includes a housing having a first compartment for holding the first medicine dose and for movement between a closed position in which access to the first medicine dose is prevented and an opened position in which access to the first medicine dose is allowed, and having a second compartment for holding the second medicine dose and for movement between a closed position in which access to the second medicine dose is prevented and an opened position in which access to the second medicine dose is allowed; a sound mechanism for selectively broadcasting audible descriptions of the first and second medicine doses; a first compartment switch for causing the sound mechanism to broadcast the audible description of the first medicine dose and for allowing the first compartment to move from the closed position to the opened position; and a second compartment switch for causing the sound mechanism to broadcast the audible description of the second medicine dose and for allowing the second compartment to move from the closed position to the opened position.

1. Field of the Invention
The present invention relates, in general, to a medicine dispenser especially designed to allow a person with visual impairments to safely dispense one or more medicine doses from a plurality of medicine doses.
2. Description of the Related Art
When people who have an acute visual handicap take medicine, they must normally rely on another person as an assistant to insure that they take the proper medicine in the proper dose and at the proper time. At best, such reliance is an annoyance to both the person with visual impairments and the assistant, especially when medicine must be taken late at night and/or early in the morning, etc. At worst, such reliance can be dangerous and life threatening if, for example, the assistant is unavailable and the person with visual impairments takes the wrong medicine.
A preliminary patentability search in class 221, subclasses 2 and 3, and class 206, subclasses 536, 538 and 828 produced the following patents which may be relevant to the present invention: Farinola, U.S. Pat. No. 3,176,815, issued Apr. 6, 1965; Shoher et al., U.S. Pat. No. 3,224,544, issued Dec. 21, 1965; Christensen, U.S. Pat. No. 3,998,356, issued Dec. 21, 1976; Carlson, U.S. Pat. No. 4,223,801, issued Sep. 23, 1980; Hicks et al., U.S. Pat. No. 4,275,384, issued Jun. 23, 1981; Behl, U.S. Pat. No. 4,473,884, issued Sep. 25, 1984; Schollmeyer et al., U.S. Pat. No. 4,504,153, issued Mar. 12, 1985; McLaughlin, U.S. Pat. No. 4,717,042, issued Jan. 5, 1988; and Cole et al., U.S. Pat. No. 4,731,765, issued Mar. 15, 1988.
Farinola and Shoher et at. disclose coin operated vending machines that provide audible messages each time coins are inserted into the machines to urge the sale of a particular brand of merchandise prior to the selection of one of the different items vended by the machines.
Christensen discloses an electronic apparatus for selectively dispensing articles at a predetermined time, such as pills in hospitals and nursing homes where stringent controls are needed to prevent mistakes in dispensing or misuse of prescribed pills.
Carlson discloses an automatic medication dispenser for providing an orderly storage of a plurality of drugs to be taken in a given time period, and for providing a signal to indicate when a specific drug is to be taken at a predetermined time interval relative to previously administered drugs.
Hicks et al. discloses a portable medicine cabinet with a timer for private use by an individual taking several different medicines and which may be carried from the home to the office or the like so as to assure that an individual does not either forget to take doses of prescribed medicines, or take doses of the prescribed medicine too often so as to endanger his health. The Hicks et al. medicine cabinet has a plurality of freely accessible compartments therein and time computer means into which a plurality of predetermined time intervals for taking a dose of the respective medicines may be entered. An indicator means is electrically connected to the time computer means and indicates the predetermined time intervals and which of the medicines should be removed from its respective compartment.
Behl discloses a portable medication dispensing system comprising a dispenser having a plurality of compartments for containing doses of medicine; audible and visual indicating means on the dispenser corresponding to the compartments; programmer means associated with the dispenser for utilizing input data pertaining to a patient's medication prescription and personal habits to develop a program corresponding to a timed medication schedule for the patient; a programmable electronic memory in the dispenser for storing the program; means for entering the program into the memory directly from the programmer means; and means in the dispenser acting responsive to the program in the memory for activating the indicating means when the time of day coincides with the time of the medication schedule.
Schollmeyer et al. discloses a pharmacist-programmable medication prompting system including a programmable prompting device that is attached to a medication container to automatically prompt a patient to take medication at prescribed times.
McLaughlin discloses a medicine dispenser for home health care including a container having a lid and a removable compartmentalized tray which can be positioned upon an interior container ledge and held within the container interior immediately beneath the lid when closed. The tray includes a series of apertures dimensioned and positioned on the periphery of the tray to interact with a series of pegs positioned on the ledge. The arrangement permits only a properly encoded tray to be positioned within the container interior. The lid is provided with a plurality of spring-loaded, hinged tray compartment covers aligned directly over corresponding tray compartments which can be selectively opened and shut to expose the contents of any desired tray compartment. The medicine dispenser is further provided with a microprocessor within the container interior which, together with a control button on the lid, controls the operation of an audible and visual alarm, as well as the automatic opening of selected compartment covers.
Cole et al. discloses a medication reminder device including a housing having a compartment for containing a plurality of individual medication units; a cover hinged to the top of the compartment; a latch mechanism mounted on the compartment to lock and unlock the cover; an electric circuit having a timer system within the housing for controlling the latch mechanism, to lock and unlock the cover at adjustable time intervals so the medication units can be removed when needed; and an audible signal emitter in the circuit activated by the timer system at the adjustable time intervals to notify a person when to remove a medication unit from the compartment.
Nothing in the above patents discloses or suggests the present invention. More specifically, nothing in the above prior art discloses or suggests a medicine dispenser including a housing having first compartment means for holding a first medicine dose and for movement between a closed position in which access to the first medicine dose is prevented and an opened position in which access to the first medicine dose is allowed, and having second compartment means for holding a second medicine dose and for movement between a closed position in which access to the second medicine dose is prevented and an opened position in which access to the second medicine dose is allowed; sound means for selectively broadcasting audible descriptions of the first and second medicine doses; first compartment switch means for causing the sound means to broadcast the audible description of the first medicine dose and for allowing the first compartment means to move from the closed position to the opened position; and second compartment switch means for causing the sound means to broadcast the audible description of the second medicine dose and for allowing the second compartment means to move from the closed position to the opened position.


A method of measuring round trip time (RTT) and a proximity checking method using the same. The method of measuring RTT includes: transmitting a hashed second random number and starting the RTT measurement; and receiving a hashed first random number from a device that received the hashed second random number and ending the RTT measurement, thereby greatly reducing repetitive encryption and decryption operations in the proximity check using a repetitive RTT measurement.

1. Field of the Invention
Methods consistent with the present invention relate to measuring round-trip-time (RTT) and proximity checking using the same.
2. Description of the Related Art
FIG. 1A is an exemplary diagram illustrating contents transmission. Referring to FIG. 1A, contents are transmitted to a device A from a contents provider CP. The device A is authorized to access the contents. Unlimited distribution of the contents to a device C may not be allowed, even if the contents are transmitted by an authorized user. For example, if the device A functions as a home server of the home network HN, the contents are transmitted within the home network HN. The home network HN includes a device B but not the device C.
Proximity checking is widely used to prevent unlimited distribution of contents.
Proximity checking is performed to determine the proximity between a device (hereinafter referred to as "sink device") that receives contents (or information whose unlimited distribution is not allowed) and a device (hereinafter referred to as "source device") which transmits the contents. If both devices are determined to be proximate to each other, contents transmission is allowed; if not, contents transmission is not allowed.
The proximity check is performed using round-trip-time (RTT). The source device measures RTT to the sink device, determines whether the measured RTT is smaller than a critical RTT, and if the measured RTT is determined to be smaller than the critical RTT, determines that the source device and the sink device are proximate to each other. For example, if the critical RTT is 7 ms, the range of the content distribution is restricted to an apartment area.
FIG. 1B is a flowchart illustrating a conventional method of measuring RTT. Referring to FIG. 1B, in Operation 110, a device A generates a first random number R1, and securely transmits the generated first random number R1 to a device B. The term "securely" means that although an external attacker may intercept a message, the first random number R1 cannot be obtained by the external attacker. Such a secure transmission is performed using a public key infrastructure (PKI).
In Operation 120, the device B transmits an acknowledge message OK to the device A.
In Operation 130, the device A generates a second random number R2, transmits the generated second random number R2, and starts a timer for measuring RTT.
In Operation 140, the device B receives the second random number R2 from the device A, generates R1⊕R2, and transmits the generated R1⊕R2 to the device A. The ⊕ means an XOR operation.
The device A receives the R1⊕R2 from the device B, ends the timer, and measures RTT. The device B does not transmit the second random number R2 but R1⊕R2 to the device A in order to prevent an attacker from intercepting the message between the devices A and B, transmitting a new message to the device A or device B, and faking RTT.
However, the conventional method of measuring RTT needs to securely transmit the first random number R1 for one-time RTT measurement every time. That is, the device A encrypts the first random number R1 using a public key of the device B and decrypts the encrypted first random number using its own private key, thereby obtaining the first random number.
The RTT measurement for one-time proximity checking is repeatedly performed several tens of times through several thousands of times. This is because, if one of the measured RTTs is smaller than the critical RTT, after the RTT is measured several tens of times through several thousands of times, the devices A and B are considered to be proximate to each other due to variability of traffic on a transmission path. However, since the conventional method of measuring RTT must perform encryptions and decryptions several tens of times through several thousands of times for the one-time proximity check, it is very inefficient and places considerable load on both systems of the devices A and B.

Method of measuring round trip time and proximity checking method using the same


A data storage circuit and a data preservation method for preserving data when a semiconductor device is in a sleep mode using a test scan chain are provided, where the data storage circuit includes a sleep mode control unit and a scan chain unit, the sleep mode control unit outputs a scan control signal and a scan clock signal in response to one of a test control signal and a sleep mode control signal received from the outside, stores an output data signal in a memory when the output data signal is received, and outputs a test pattern data signal as a scan data signal when the test pattern data signal is received, the scan chain unit outputs a normal data signal stored inside of the scan chain unit as the output data signal to the sleep mode control unit or receives and outputs the scan data signal to a combinational circuit unit in response to the scan control signal and the scan clock signal, and the data storage circuit and the data preservation method prevent a loss of data in a sleep mode of a semiconductor device, and reduce power consumption in a standby state.

1. Field of the Invention
The present disclosure relates to semiconductor devices, and more particularly, to methods for controlling sleep modes of semiconductor devices.
2. Description of the Related Art
Some semiconductor devices include a sleep mode function. In order to reduce power consumption of a semiconductor device, a control system may apply a control signal to a semiconductor chip that is expected not to operate for a period of time, thus placing the semiconductor device into a sleep mode. A sleep mode is also sometimes referred to as a standby mode or state, a stop mode, or a power down mode. In each mode, the level of source voltage applied to the semiconductor device is reduced. When a semiconductor device is used in a portable device, a sleep mode function of the semiconductor device has a great effect on reducing power consumption of the portable device. An example of a conventional semiconductor device having a sleep mode function is disclosed in U.S. Pat. No. 6,137,744.
On the other hand, a semiconductor device in a sleep mode can be placed back to an active mode when required. When switching from a sleep mode into an active mode, a semiconductor device has to return to a state prior to the switch to sleep mode, and operate normally. Generally, when a semiconductor device operates in a normal mode, data generated by internal combinational circuits is stored in a temporary memory space such as internal flip-flops. However, since power sources supplied to most of the circuits in the semiconductor device are cut when the semiconductor device is switched to the sleep mode, the data stored in the flip-flops is lost. Accordingly, when such a semiconductor device is switched again from a sleep mode to an active mode, the semiconductor device cannot recover its previous state and does not operate properly.
The problem described above can be solved if the flip-flops are not placed in a sleep mode even if the semiconductor device is placed in the sleep mode. However, a solution as described above may restrict any reduction of power consumption when the semiconductor device is in the standby state. In order to prevent data loss and reduce power consumption of the semiconductor device in a standby state when entering a sleep mode, the semiconductor device can store data in an additional storage space and be switched to a sleep mode. However, in this case, since the semiconductor device has to include additional circuits for storing the data, such as circuits forming a path in which the data is transferred to a storage space such as a memory, the manufacturing cost of the semiconductor device is increased.

Circuit and method for preserving data in sleep mode of semiconductor device using test scan chain


A lawn mower for use in a walking mode and a riding mode, having a chassis frame, an engine mounted on a rearward position of the chassis frame, front wheels, driven rear wheels, transmissions for transmitting drive from the engine to the rear wheels after varying speed of the drive, a grass cutting unit suspended from the chassis frame, a driver's seat mounted on the chassis frame, and a handle post supporting control levers for controlling the transmissions. The handle post is pivotable between a first position for the walking mode in which the control levers are disposed rearwardly of the chassis frame, and a second position for the riding mode in which the control levers are disposed adjacent the driver's seat. The handle post includes a vertical post portion extending laterally of the lawn mower, and a horizontal post portion curved from the vertical post portion to extend transversely of the lawn mower. The control levers are provided on the horizontal post portion.

1. Field of the Invention
The present invention relates to a lawn mower for use in a walking operator mode and a riding operator mode.
2. Description of the Related Art
A riding type lawn mower, as disclosed in U.S. Pat. No. 4,957,183, has an engine mounted on a front portion of a vehicle body, a driver's section disposed rearwardly, and a grass cutting unit underslung between front and rear wheels. The mower runs on the wheels driven respectively by hydraulic motors, and is steerable by turning the wheels up to about 90 degrees with a steering wheel disposed in the center and forwardly of a driver's seat.
The riding type lawn mower having the above construction is capable of a small, sharp turn with the center of turning moved to a position inwardly of a peripheral edge of the grass cutting unit. This turning capability provides the advantage of realizing an efficient grass cutting operation leaving no uncut patches. However, since the engine is mounted forwardly of the driver's section, the mower has an extensive fore and aft length. Consequently, the driver has difficulties in observing grass patches ahead of the mower during a grass cutting run. In addition, when boarding and alighting from the mower, the driver has the inconvenience of having to move through a narrow space between the driver's seat and steering wheel.
In the case of walking operator type lawn mower, one known example, as disclosed in U.S. Pat. No. 4,934,989, has a grass cutting unit mounted between caster type front wheels and engine-driven rear wheels, and control levers extending rearwardly for a walking operator to steer the mower. This lawn mower is easily controllable by operating transmission clutches provided for the rear wheels, respectively. It is possible to drive the mower along a complicated curve to engage in a grass cutting operation. However, when the mower is caused to run along a long straight line, the operator must follow the mower in a tedious walk. The walking operator type lawn mower has a low reputation for use in an operation involving such long straight walks.
As further examples, Applicants have disclosed lawn mowers for use in a walking mode as well as a riding mode, in U.S. patent applications Ser. No. 07/865,726 filed Apr. 8, 1992 and Ser. No. 07/874,647 filed Apr. 27, 1992. In each of these mowers, front control levers disposed adjacent a driver's seat and rear control levers arranged rearwardly of a vehicle body are operatively connected to transmissions for varying drive speeds of right and left rear wheels, respectively. The user may freely choose to use this type of lawn mower in the walking mode or in the riding mode. However, this type of lawn mower has the disadvantage of requiring a complicated link mechanism to allow the transmissions to be controlled both by the front control levers and by the rear control levers. As a further disadvantage, the rear control levers are obstructive when the mower is used in the riding mode, and the front control levers when the mower is used in the walking mode.

Lawn mower having a steering handle switchable between a walking mode and a riding mode


Finite-state transducers and weighted finite-state automata may not be determinizable. The twins property can be used to characterize the determinizability of such devices. For a weighted finite-state automaton or transducer, that weighted finite-state automaton or transducer and its inverse are intersected or composed, respectively. The resulting device is checked to determine if it has the cycle-identity property. If not, the original weighted finite-state automaton or transducer is not determinizable. For a weighted or unweighted finite-state transducer, that device is checked to determine if it is functional. If not, that device is not determinizable. That device is then composed with its inverse. The composed device is checked to determine if every edge in the composed device having a cycle-accessible end state meets at least one of a number of conditions. If so, the original device has the twins property. If the original device has the twins property, then it is determinizable.

1. Field of Invention
This invention is directed to systems and methods for determining if a finite-state automaton or a finite-state transducer is determinizable.
2. Description of Related Art
Finite-state automata and finite-state transducers, whether weighted or unweighted, are used in many fields to represent complex systems. For example, weighted finite-state transducers are used in many recognition applications, such as speech recognition, gesture recognition and multimodal recognition.
Finite-state transducers are also used in speech-to-text and text-to-speech systems to represent various aspects of the recognition and/or conversion process. Finite-state automata and finite-state transducers are classical computational devices that can be used in a large variety of locations. A weighted finite-state automaton is a finite-state automaton in which each transition between two states is labeled with some weight in addition to the usual input symbol. Finite-state transducers are finite-state automata whose transitions are labeled with both input labels and output labels. Thus, weighted finite-state transducers include input labels, output labels and weights. Weighted finite-state automata and weighted finite-state transducers can be used in text processing, speech processing and image processing to account for the variability within the input data and to rank various hypotheses for the correct processing of the data.
Weighted finite-state automata and finite-state transducers are used to provide a common representation for each component of a complex system in many applications. Such weighted finite-state automata and finite-state transducers can use generalized methods for simplifying and/or combining components, such as the composition of two weighted finite-state automata or transducers. A finite-state automaton or transducer is deterministic if that finite-state automaton or transducer has a unique initial state and if no two transitions of the finite-state automaton or transducer leaving the same state have the same input label. The time efficiency of such finite-state automata or transducers is substantially increased when the finite-state automata or transducers that are implemented are deterministic. Additionally, the size, in number of states and/or the number of transitions between states, can be reduced for such deterministic finite-state automata or transducers using generalized minimization methods.
U.S. Pat. No. 6,243,679 to Mohri et al., which is incorporated herein by reference in its entirety, discloses systems and methods for both determinizing and minimizing a finite-state automaton or transducer. That is, the incorporated 679 patent discloses systems for converting a non-deterministic weighted finite-state automaton, such as that shown in FIG. 1, into a deterministic weighted finite-state automaton, such as that shown in FIG. 2. The incorporated 679 patent also discloses systems and methods for minimizing weighted finite-state automata and transducers.
However, unlike unweighted finite-state automata, weighted finite-state automata and finite-state transducers, whether weighted or unweighted, may not be determinizable. While the determinizability of many trivial weighted finite-state automata and finite-state transducers can be determined by inspection or using known techniques for determining the determinizability of such weighted finite-state automata or finite-state transducers, such methods cannot be used with the finite-state transducers or weighted finite-state automata used to represent components of any reasonable complexity.
In particular, the known methods for determining the determinizability of finite-state transducers and weighted finite-state automata have a complexity that is on the order of the sixth power of the number of states within the finite-state transducer or the weighted finite-state automata. Such conventional methods for determining the determinizability of a particular finite-state transducer or weighted finite-state automaton are not guaranteed to return an answer in a reasonable period of time and, for very large finite-state transducers used in speech, gesture, and/or multimodal recognition systems, which may have millions of states, would not have been guaranteed to complete within the current age of the universe.
As a result, rather than attempting to determine if a particular finite-state transducer or weighted finite-state automaton is determinizable, current practice is to attempt to determinize that finite-state transducer or weighted finite-state automaton. Then, if the determinization method does not halt within a reasonable period of time, the non-deterministic finite-state transducer or weighted finite-state automaton being determinized is assumed to be undeterminizable. However, this causes both waste of computer resources expended in attempting to determinize a non-determinizable non-deterministic finite-state transducer or weighted finite-state automaton, as well as unnecessarily abandoning attempts to determinize determinizable non-deterministic finite-state transducers or finite-state automata who nonetheless have not terminated within the reasonable period of time.
In particular, A. Weber et al., "Economy of Description for Single-Valued Transducers," (Information and Computation, 118(2):327-340, 1995), M-P Beal, et al., "Squaring Transducers: An Efficient Procedure for Deciding Functionality and Sequentiality," in (Proceedings of LATIN'2000, Lecture Notes in Computer Science, v. 1776, 2000), and A. L. Buchsbaum, et al., "On the Determinization of Weighted Finite Automata," (SIAM, Journal of Computing, 30(5):1502-1531, 2000), each incorporated herein by reference in its entirety, disclose the various methods that are usable to determine the determinizability of a finite-state transducer or a weighted finite-state automaton. However, all of these methods suffer from the drawbacks outlined above.

Systems and methods for determining the determinizability of finite-state automata and transducers


A jet regulator includes a ring-shaped or sleeve-shaped jet regulator housing, the outlet face side of which is formed as a perforated, grate and/or mesh structure with throughflow openings bordered by flow-guiding walls. The perforated, grate and/or mesh structure on the outlet face side is produced at least in regions and at least on the surface from a manually deformable dimensionally elastic plastic material. The outlet face side of the jet regulator housing is in the form of an outlet disk which can be inserted into the jet regulator housing and which bears the perforated, grate and/or mesh structure. The separate configuration of the outlet disk on the one hand and the jet regulator housing on the other hand facilitates the separate production of said jet regulator constituents even from materials which cannot be welded or otherwise connected to one another, if appropriate in different production processes.

Already known from DE 198 52 411 A1 is a jet regulator which can be mounted on a sanitary outlet fitting. The already-known jet regulator has a jet regulator housing which is in the form of a sleeve-shaped molded body on which a soft or dimensionally elastic plastic material is injection-molded at the outlet side. That constituent of the jet regulator housing which is composed of soft or dimensionally elastic plastic material forms a soft and/or water-repellent surface, the aim of which is to substantially prevent limescale formation. It is the intention for adherent limescale deposits to be easily detachable by slight manual deformation of the soft or dimensionally elastic plastic material which is injection-molded on the surface. Since it must be ensured with regard to the material selection that the soft or dimensionally elastic plastic material can be injection-molded onto the relatively hard or dimensionally rigid plastic material of the jet regulator housing, the production of the already-known jet regulator can require a not inconsiderable amount of additional outlay.
It is therefore the object to create a jet regulator of the type mentioned in the introduction which can be produced from a wide variety of materials with relatively little outlay.


A device and method for checking surfaces in the interior of holes, depressions, or the like. The device and method are developed in such a manner that a multicolor light beam can be produced with a light source, wherein a light beam, due to the chromatic aberration of the imaging optics, can be focused onto several points at different distances from the imaging optics, such that the distance to the surface can be determined from the spectrum of the detected light beam.

The invention relates to a device for inspecting surfaces in the interior of holes, recesses, or the like, where the device comprises a light source for producing a light beam, where the light beam can be focused by imaging optics, where the focused light beam can be deflected onto the surface, and where a sensor device is provided for detecting the reflected light beam.
Surface inspections in the interior of holes, recesses, or the like, in particular of boreholes or small cracks with dimensions in the millimeter range, represent an important task in many fields of technology. High quality and close-tolerance bore holes are frequently needed when they are provided to receive movable parts such as pins, cylinders, or small pistons, e.g. in pressure valves. Pressure valves are used in pneumatics but also in other fields such as in automobile technology for fuel injection. There in the meantime, test pins for electrical circuits with pneumatic cylinders with a diameter of 2 mm are finding application. These very small cylinders are necessary in order to keep up with electrical circuits which are constantly getting smaller. Close-tolerance bore holes are also required for shrink connections, where said bore holes cannot be allowed to be subject to damage due to burrs or bubbles. Moreover, it can also be of importance in holes outside of the millimeter range to know the surface quality precisely. Thus, for example, brake cylinders in a motor vehicle must have a particularly high-quality surface since small chips or burrs in the cylinders can lead to the destruction of the parts after even a short time.
For the inspection of surfaces, essentially two processes are used in practice at present. In one system a glass wedge forms optics with which nearly 360° of the surrounding surface can be imaged on a light wave guide bundle. The light wave guide bundle frequently comprises several thousand individual fibers which together conduct an image to a camera. By suitable image processing, structures on the surface can be recognized thereby. However, their actual size, in particular their three-dimensional extension, cannot be determined.
In another technology customary in practice, a monochromatic light beam is deflected onto the surface to be examined, where this light beam is always kept focused on the surface. If the distance between the optics and the illuminated image point changes as a consequence of unevenness of the surface and thus the light beam is no longer focused, then an automatic focusing circuit adjusts the optics in such a manner that the light beam is once again focused on the surface. Via this correction of the optics, the change in distance can be detected. In this way the surface can indeed be measured in three dimensions, but due to the necessary tracking of the focusing only relatively slow measurement speeds can be achieved. An inspection in a running production process thus cannot be realized.
The present invention is thus based on the objective of developing and extending a device of the type stated in the introduction in such a manner that, as far as possible, a rapid, simple, and reproducible inspection of surfaces in the interior of holes, recesses, or the like is possible with dimensioning up into the millimeter range and with the simplest construction. Furthermore, a corresponding process will be specified.

Device and method for inspecting surfaces in the interior of holes


An erasable ink composition for writing on an impervious writing surface comprising an organic solvent, a resin, a pigment, and a separating agent which comprises a polyoxyethylene polyoxypropylene monoalkyl ether which is liquid at normal temperatures in an amount of 5-20% by weight, and optionally at least one organic compound selected from the group consisting of a carboxylic acid ester and a polyoxypropylene monoalkyl ether which is liquid at normal temperatures in an amount of 2-10% by weight in conjunction.

A variety of erasable ink composition to write on an impervious writing surface to provide writing thereon which is readily erasable by wiping with, for example, an eraser made of felt are already known, as disclosed in, for example, Japanese Patent Application Laid-open No. 63-43981, No. 62-265377 and No. 2-129278. However, these prior erasable ink compositions contain carboxylic acid esters, liquid paraffin, silicone resins or nonionic surfactants as a separating agent therein, and thus it is known that they provide writing which is insufficiently erasable depending upon the material of impervious writing surface. Namely, the prior erasable ink compositions have erasability dependendent on the material of impervious writing surface. It is also known that such an ink composition provides writing which is not readily erasable after long standing. Namely, the prior erasable ink compositions have erasability dependendent on time.

Erasable ink composition for writing on impervious surface


A method of replacing an existing part or parts on a structure such as an aircraft. The structure is inducted for modification. An existing part is removed and a new part is temporarily installed. Hole locations are digitally transferred to the new part, e.g., photographically captured in a three-dimensional coordinate measurement system, converted to targets printable in a laser projection system. Targets are laser projected or printed on the replacement part. Holes are drilled at each printed target. The holes drilled at printed targets match hole locations on the existing part. Then, the new/replacement part is permanently attached to the structure.

1. Field of the Invention
The present invention generally relates to aircraft maintenance and, more particularly, to providing "as built" hole locations on replacement parts for installation on aircraft.
2. Background Description
Vehicle (e.g., military and commercial aircraft) maintenance and repair may require replacing existing parts. Frequently, existing parts have been modified, e.g., for upgrading or retrofitting the vehicle with state of the art technology. Normally such modification is done individually on a vehicle by vehicle basis, e.g., during scheduled maintenance or routine repair. Also, final assembly or field repairs may have necessitated modifying the existing structure. Thus, the existing parts may vary with some variation of hole patterns and hole diameters from original equipment manufacturer (OEM) parts and, moreover, from vehicle to vehicle. Consequently, it is unlikely that replacement parts are pre-drilled to exactly match existing parts in the field and typically require custom drilling in existing parts and/or structure.
Thus, prior to/during installation, field service personnel must accurately reproduce hole patterns and diameters from the existing parts onto new replacement parts relative to the existing holes. Traditional prior art approaches (e.g., what is known as mate-drilling), frequently have been ineffective. Access restrictions can limit mate drilling, especially where existing holes are inaccessible and operator fatigue can provide less than satisfactory results, e.g., from missed holes or improper alignment. Finding satisfactory work-arounds or correcting errors can increase cycle time and reduce hole quality. Consequently, this has become a significant cost problem and a schedule driver, especially on large applications such as wing skin replacements.
Accordingly, there is a need for providing "as-built" replacement parts and, more particularly for accurately and rapidly collecting hole locations and centerlines and precisely transferring existing holes to new replacement parts for efficient field assembly.

Method of rapid hole transfer to replacement parts


A deformable calendar in the form of a ball-shaped device sized to fit a user's hand and having a tabular register of days and months printed on its exterior surface. The device has a tightly-packed particulate core and a resilient outer covering. A user can increase the size of any part of the printed register by manually stretching the associated part of the covering. The printed register is preferably located on at least two opposite sides of the device so that a user can view any part of the register by a suitable manual manipulation of the device.

A calendar is typically in the form of one or more flat sheets of paper or the like that have a printed tabular register of months and days on one surface thereof. The calendar is usually adapted to be hung on a wall or located on a desk so that it is readily viewable.
Prior art calendars are not adapted to be easily handheld. Their form does not engender a user's holding them for any period of time. In addition, prior art desk-located calendars require a significant amount of space and are often inadvertently covered up by papers whereby the calendar is not readily visible or accessible.


An array substrate for the liquid crystal display device, the array substrate includes: a first insulating film pattern on an insulating substrate and having an opening; a first light shielding film pattern on the first insulating film pattern including the opening; a gate insulating film over the entire surface of the insulating substrate including the first light shielding film pattern; an active layer on top of the gate insulating film and overlapping the first light shielding film pattern; a pixel electrode on top of the gate insulating film to be separated from the active layer; a source electrode and a drain electrode on top of the active layer, the drain electrode being separated from the source electrode and directly connected to the pixel electrode; a passivation film over the entire surface of the insulating substrate including the source electrode and the drain electrode; a second insulating film pattern on top of the passivation film and overlapping the first light shielding film pattern; a second light shielding film pattern on the second insulating film pattern; and a plurality of divided common electrodes on top of the passivation film and overlapping the pixel electrode.

1. Field of the Disclosure
The present disclosure relates to a liquid crystal display device (hereinafter, abbreviated as LCD), and more particularly, to an array substrate for a liquid crystal display device having a light shielding film structure formed above and below a thin film transistor to block light, such as sunlight, from a high-luminance backlight, and a method for fabricating the same.
2. Background
In general, the driving principle of a liquid crystal display (LCD) device uses an optical anisotropy and polarization properties of liquid crystal. Liquid crystals have a thin, long structure, so they have orientation in an alignment of molecules, and the direction of the alignment of molecules can be controlled by intentionally applying an electric field to the liquid crystal.
Thus, when the direction of the alignment of molecules of the liquid crystal is adjusted, the alignment of molecules of the liquid crystal can be changed, and light is refracted in the direction of the molecular alignment of the liquid crystal by optical anisotropy, thus displaying image information.
Currently, an active matrix liquid crystal display (AM-LCD) (which will be referred to as an 'LCD', hereinafter) in which thin film transistors and pixel electrodes connected to the thin film transistors are arranged in a matrix form has come to prominence because of its excellent resolution and video implementation capabilities.
The LCD includes a color filter substrate (i.e., an upper substrate) on which a common electrode is formed), an array substrate (i.e., a lower substrate) on which pixel electrodes are formed, and liquid crystal filled between the upper substrate and the lower substrate. In the LCD, the common electrode and the pixel electrodes drive liquid crystal by an electric field applied vertically, having excellent characteristics of transmittance, aperture ratio, and the like.
However, the driving of liquid crystal by the electric field applied vertically is disadvantageous in that viewing angle characteristics are not good. Thus, in order to overcome the shortcomings, a method for driving liquid crystal by in-plane field has been newly proposed. The method for driving liquid crystal by in-plane field has excellent viewing angle characteristics.
Although not shown, the in-plane switching mode LCD is configured such that a color filter substrate and a thin film transistor substrate face each other, and a liquid crystal is interposed therebetween.
A thin film transistor, a common electrode, and a pixel electrode are formed on each of a plurality of pixels defined on the thin film transistor substrate. Also, the common electrode and the pixel electrode are separated to be parallel on the same substrate.
The color filter substrate includes gate lines and data lines formed on the thin film transistor substrate, a black matrix formed at portions corresponding to the crossings of the gate lines and the data lines, and color filters provided to corresponds to the pixels. The liquid crystal layer is driven by an in-plane field of the common electrode and the pixel electrode.
In the in-plane switching mode LCD configured as described above, the common electrode and the pixel electrode are formed as transparent electrodes in order to secure luminance, but only portions of both ends of the common electrode and the pixel electrode contribute to improvement of the luminance due to the distance between the common electrode and the pixel electrode in terms of design and most regions block light.
Thus, a fringe field switching (FFS) technique has been proposed to maximize the luminance improvement effect. The FFS technique precisely controls liquid crystal to eliminate a color shift and obtain high contract ratio, implementing high screen quality compared with the general in-plane switching technique.
The related art FFS mode LCD device having the merit of implementing such high screen quality will now be described with reference to FIGS. 1 and 2.
FIG. 1 is a plan view of a thin film transistor arrary substrate of the related art FFS mode LCD device.
FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1, schematically illustrating the thin film transistor array substrate of the related art FFS mode LCD device.
As shown in FIGS. 1 and 2, the thin film transistor array substrate for the related art LCD device includes: a plurality of gate lines 13 extending in one direction and separated to be parallel on a transparent insulating substrate 11 and a gate electrode 13a extending from the gate lines 13; a gate insulating film 15 formed over the entire surface of the substrate including the gate electrode 13a; a plurality of data lines 21 formed on top of the gate insulating film 15 and defining pixel regions at the crossings of the gate lines 13 and the data lines 21; and a thin film transistor T provided at the crossing of the gate line 13 and the data line 21 and including the gate electrode 13a, an active layer 19 located above the gate insulating film 15, an ohmic contact layer 20, and a source electrode 21a and a drain electrode 21b separate from each other.
The gate electrode 13a is formed to cover the regions of the source electrode 21a, drain electrode 21b, and active layer 19 of the thin film transistor T, where a channel is formed.
Thus, the gate electrode 13a prevents leakage current generated in response to light 30 coming from below the substrate and vertically incident from a backlight.
Moreover, a pixel electrode 17 having a large area is disposed on the insulating substrate 11 in the pixel regions defined at the crossings of the gate lines 13 and the data lines 21, and a plurality of divided common electrodes 25 are disposed on top of the pixel electrode 17 to be separated from each other, with a passivation film 23 interposed therebetween.
The pixel electrode 17 overlaps the divided common electrodes 25, and is directly connected to the drain electrode.
According to the thus-configured thin film transistor array substrate for the related art LCD device, when a data signal is supplied to the pixel electrode 17 via the thin film transistor T, the common electrodes 25 to which a common voltage is supplied form a fringe field, making the liquid crystal molecules arranged in a horizontal direction between the substrate 11 and the color filter substrate (not shown) rotate according to dielectric anisotropy. The transmittance of light that transmits through the pixel regions vary according to the degree of rotation of the liquid crystal molecules, thus implementing gray scales.
According to the thus-configured array substrate for the related art FFS mode LCD device, the gate electrode is formed to cover the source electrode, drain electrode, and active layer regions of the thin film transistor T, where a channel is formed. As such, as shown in FIG. 2, the gate electrode prevents leakage current generated in response to light 30 coming from below the substrate and vertically incident from the backlight.
In the thin film transistor for the related art LCD device, however, the source electrode, drain electrode, and active layer regions where the channel is formed are directly exposed by light 40, such as sunlight, coming from an outside environment, whereby light scattered or reflected inside the device, including the light incident from the outside, enters the channel.
Accordingly, according to the related art, it is not possible to prevent the light 40 scattered or reflected inside the device, including the light incident from the outside, from being incident from above the thin film transistor and entering the channel. As a result, leakage current is generated, and this makes it impossible to display a proper image under the driving condition of the display device. Especially, when the channel portion of the active layer is exposed to light, it fails to function as a channel because of the generation of leakage current.
Consequently, it is not possible to control various voltages required for the driving of the LCD device, thereby lowering display performance.

Array substrate for liquid crystal display device and method for fabricating the same


A game hoist for mounting to the cargo rack of an all-terrain vehicle (ATV). The game hoist is mounted to the cargo rack using a base plate which has one or more sets of angle brackets mounted to the underside of the base plate. The sets of angle brackets form pockets or receptacles to slidably receive respective rods of the cargo rack. The base plate has an upward facing cylindrical post which receives a cylindrical column. A telescoping boom is provided with a cylindrical collar which fits over the top end of the column. The telescoping boom has an inner cylindrical member which is slidingly received in an outer cylindrical member. The inner cylindrical member may be telescoped outward from the outer cylindrical member. The outer end of the inner cylindrical member is provided with a manually operated winch. The winch is desirably provided with a ratchet mechanism.

The present invention relates to a hoist for lifting game animals, and in particular, to such a hoist which is mountable to an all-terrain vehicle (ATV) and may be mounted and demounted without the use of permanent fasteners.
Game animals carcasses, particularly those of large animals such as deer, are quite heavy and can present a challenge to the hunter wishing to load a carcass into an ATV. Mechanical hoists are known to be used for this purpose.
Muzzi et al. (U.S. Pat. No. 5,662,451) discloses such a hoist for lifting game animals. The Muzzi et al. device is specifically adapted for mounting to the cargo rack of an ATV. The hoist comprises a horizontal boom attached to a vertical support shaft. The hoist is attached to a base. The Muzzi et al. device mounts to the cargo rack with a base using permanent fasteners. The base is provided with slots through which U-bolts are attached. While Muzzi discloses a telescoping vertical shaft and a hand operated winch, it does not disclose a rotating telescoping boom that may be extended manually. Neither does Muzzi disclose any arrangement by which the hoist is easily assembled and disassembled without using bolts or other permanent fasteners.
Hawkins (U.S. Pat. No. 4,069,922) discloses a hoist mounted on a pick-up truck. The hoist includes a telescoping rotatable boom and an outboard support leg. Hawkins does not disclose a means for mounting the device to an ATV cargo rack.
Koscinsky, Jr. (U.S. Pat. No. 5,445,487) likewise discloses an elongated lower mast member, a rotatable cantilevered telescoping boom and a plurality of different mounting members for mounting the assembly to different support structures. Although several different mounting schemes are disclosed, none are specifically adapted to mounting the device to an ATV cargo rack.
Various other patents disclose different types of lifts or hoists mounted to vehicles. York (U.S. Pat. No. 4,806,063) discloses a hoist specifically adapted to lifting game animals. The York device is mounted to a standard trailer hitch. Webb, Jr. (U.S. Pat. No. 4,640,658) also discloses a device for mounting a carrier to the tongue of a trailer hitch.
The problems not solved by the prior art include the desirability of mounting a game hoist to an ATV cargo rack without using bolts or similar permanent fasteners, the need for a boom to be able to extend to lift a game animal carcass over a cargo rack, and the desirability of being able to assemble and disassemble a hoist in the field manually without the use of mechanical fasteners. It is also desirable that a disassembled hoist be compact and easily stowed on an ATV.
The limitations of the prior art are overcome by the present invention as described below.