Disclosed is a system that includes both an Airway and Ventilation device (AV) and an Automated External Defibrillator (AED) device. The system is provided with components for assisting only minimally trained persons to operate it in emergency situations involving respiratory failure and/or cardiac arrhythmias. The system includes one or both of a mask for applying non-invasive ventilation and a ventilation tube for applying invasive ventilation.

Publications and other reference materials referred to herein, including reference cited therein, are incorporated herein by reference in their entirety and are numerically referenced in the following text and are respectively grouped in the appended Bibliography, which immediately precedes the claims.
Acute respiratory failure is an emergency medical condition in which there is extremely low oxygen level or extremely high carbon dioxide level in an individual's blood. In acute respiratory failure the lungs can become unable to replenish oxygen supplies because of an airway obstruction or the presence of excessive fluids. Acute respiratory failure is usually fatal if an individual does not receive immediate medical services. Doctors or emergency medical technicians will try to open a sufficient airway, supply oxygen, and determine any underlying causes in order to provide additional treatment. The onset of an acute or chronic respiratory failure may occur due to an asthma attack, smoke inhalation, choking, or drowning, or many other pulmonary diseases that obstruct the intake of air.
Respiratory failure is a common name given to a wide variety of medical situations. For example, Chronic Obstructive Pulmonary Disease (COPD) is now the third leading cause of death globally. One out of every four men and one of every six women who live to be 95 years old will develop COPD. COPD is an umbrella term used to describe lung disease associated with airflow obstruction. Most generally, emphysema, and chronic bronchitis, either alone or combined, fall into this category. In the US, there are over 1.5 million emergency department visits by adults, over 725,000 hospitalizations due to COPD and over 140,000 COPD-related deaths (2008). As of 2009, 300 million people worldwide were affected by asthma leading to approximately 250,000 deaths per year [1]. It is estimated that asthma has 7-10% prevalence worldwide [2]. Asthma is responsible for more than 2 million visits to the emergency department (ED) in the United States each year, with 1 in 4 patients requiring admission to a hospital. Annually there are 5,000 to 6,000 asthma-related deaths in the United States, many occurring in the pre-hospital setting. Severe asthma accounts for approximately 2% to 20% of admissions to intensive care units, with up to one third of these patients requiring intubation and mechanical ventilation [3].
Drowning is responsible for more than 500,000 deaths each year worldwide. Drowning is a leading preventable cause of unintentional morbidity and mortality. According to the 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science, The most important and detrimental consequence of submersion is hypoxia; therefore, oxygenation, ventilation, and perfusion should be restored as rapidly as possible
Other pathologies which may result in respiratory failure include Angioedema of the airway due to Anaphylaxis; Pharyngeal infections; upper airway foreign body; Rib fractures with Flail chest; Pulmonary COPD or Asthma exacerbations; Pulmonary embolism; Pneumothorax; Pulmonary or distant infections with developed ARDS; Pulmonary contusion or other lung injury; Pulmonary insufficiency due to Cardiac failure or acute coronary syndrome; pulmonary edema; Arrhythmia; Stroke and other CNS pathologies. Oxygen is a potent and readily available treatment for many of the above causes of dyspnea and should be administered liberally.
According to the AHA 2010 guidelines, patients with severe life-threatening asthma require urgent and aggressive treatment with simultaneous administration of oxygen, bronchodilators, and steroids. Short-acting ß-agonists provide rapid, dose-dependent bronchodilation with minimal side effects. Salbutamol, or albuterol, is a common short-acting Short-acting ß-agonists used for the relief of bronchospasm in conditions such as asthma and chronic obstructive pulmonary disease. It is marketed as Ventolin among other brand names.
Salbutamol sulfate is commonly the form used for inhalers, for a direct effect on bronchial smooth muscle. In this form of delivery, the maximal effect of salbutamol can take place within five to 20 minutes of dosing, though some relief is immediately seen. Salbutamol is typically used to treat bronchospasm due to allergy or asthma attack, exercise-induced bronchospasm, as well as chronic obstructive pulmonary disease, and cystic fibrosis.
Systemic corticosteroids are the only treatment for the inflammatory component of asthma proven to be effective for acute asthma exacerbations. The use of inhaled steroids may hasten the resolution of airflow obstruction. In fact, Inhaled corticosteroids (ICS), or inhaled steroids, are the most potent anti-inflammatory controller medications available for the treatment of asthma. Steroids May also be extremely effective for the treatment of respiratory failure that is induced by cerebrovascular accident (CVA) also known as stroke.
Vasopressor agents that are given during CPR aim to improve aortic diastolic pressure. Consequently, increases in coronary and cerebral perfusion pressures enhance both myocardial and cerebral blood flow and improve survival. Adrenergic agonist; adrenaline (epinephrine) is routinely used to enhance cerebral and myocardial blood flow by preventing arterial collapse and by augmenting aortic diastolic pressure through alpha 1 and 2 receptors [6]. These drugs, if directly provided to the patient's mouth in the right timing, may very well be the difference between life and death.
In general, there are two types of critical care devices currently available to the public: first aid kits, including bandages and the like, and an Automated External Defibrillator (AED) being a portable electronic device that applies electrical shock therapy for the treatment of cardiac arrhythmias. Oxygen therapy equipment for active ventilation of a patient, is in most cases only available to medical professional providers of paramedics and doctors in the EMS or hospital, and is not available to non-medical personal.
In current emergency care, tracheal intubation is still the main practice for treating acute respiratory failure by paramedics and professional medical care giver. Tracheal intubation is a highly invasive and extremely uncomfortable medical procedure that requires skills, training and experience, and it is associated with significant and often fatal complications such as loss of speech, pulmonary aspiration of stomach contents, bradycardia and tracheal injury and perforation.
Non-invasive ventilation (NIV) is defined as 'delivery of ventilatory support via the patient's upper airway using a mask or similar device' and includes both continuous positive airway pressure (CPAP) and non-invasive positive pressure ventilation (NPPV). NIV was initially used to treat chronic obstructive pulmonary disease related respiratory failure and prevent the need for mechanical ventilation and the attendant complications associated with invasive ventilation but is now emerging as a useful alternative treatment strategy to mechanical ventilation in a number of different clinical situations. Worldwide, the use of NIV has more than doubled in the past 10 years. In the UK where the previous decade has seen a disproportionate increase in level 2 critical care beds, NIV use has risen steadily. Yet, large international geographical variations remain and NIV use remains relatively low in areas such as North America.
Due to the substantial mortality and morbidity associated with tracheal intubation, the use of Non-Invasive Ventilation (NIV) is gradually increasing; currently it is mainly used in hospital wards and in the long term home care treatment of chronic respiratory problems. NIV has its own drawbacks—if the patient is unconscious NIV may not be effective enough in supplying oxygen to the patient, and, since there must be created a perfect seal to the face for keeping the air pressure inside the mask cavity, a patient who vomits may be at risk of aspiring the fluids if they are not cleared from the mask, or if the mask is not removed quickly from his face. Non-invasive ventilation is still a challenge for medical practice.
Firemen, police officers, or lifeguards acquire substantial training in basic or advanced life support. They are trained to perform CPR and use a defibrillator, and although immensely helpful, they are unable to provide emergency oxygen due to lack of appropriate solutions. Performing tracheal intubation is carried out only by highly experienced and professional medical teams in a well-equipped environment such as the ambulance or the hospital ward, while non-invasive solutions are unfortunately not available outside of such settings, e.g. in public spaces or swimming pools.
An Automated External Defibrillator (AED), which is commonly available in public spaces, is used in cases of life threatening cardiac arrhythmias which can lead to cardiac arrest. As accepted in medical practice, shockable cardiac arrhythmias include ventricular fibrillation and pulseless ventricular tachycardia (VF/VT). In both these types of shockable cardiac arrhythmia, the heart is electrically active, but in a life-threatening, dysfunctional pattern. In ventricular tachycardia, the heart beats too fast to effectively pump blood. In ventricular fibrillation, the electrical activity of the heart is chaotic, preventing the ventricles from effectively pumping blood. The AED provides electrical shock to a patient in cardiac arrhythmias (VF/VT) in order to re-synchronize the electric activity of the heart muscles, and revive the heart.
In respiratory failure, not enough oxygen is reaching the lungs to properly oxidize the blood and clear the carbon dioxide. At first, the activity of the heart remains normal, so the heart is pumping and circulating the blood throughout the body. But as the circulating blood is not oxygenated properly in the lungs due to obstruction in respiration, the oxygen blood saturation decreases rapidly, until reaching a certain low oxygen level at which the heart starts to fibrillate. Doctors refer to such fibrillation as non-cardiac VF, because this kind of fibrillation does not originate from a cardiac problem but from a respiratory problem. Although this kind of fibrillation is also treated by electric shock, the chances of surviving such non-cardiac fibrillation is much lower than in cardiac VF, as non-cardiac VF is indicative of a poor clinical situation and its success is much dependent on the oxygen level in the blood and on medications
Cardiac defibrillation therapy is quite effective if applied within a short time window of 5-8 min from the time of cardiac VF/VT incidence. Studies show a 71% survival rate in witnessed cardiac arrest in casinos or airports, where AED is readily available, and the patients were treated within three minutes. After eight minutes survival rate drop dramatically.
In contrast, non-cardiac VF defibrillation has much lower chance for success, as it is the outcome of very low oxygen blood saturation and is indicative of a poor clinical condition. In fact, without restoring ventilation and elevating blood oxygen level, there is little chance of saving the patient's life.
In order to increase blood oxygen level quickly and improve the success rate of defibrillation in a non-cardiac VF, oxygen must be applied and an effective CPR must be carried out. The more effective the CPR, the faster the blood oxygen level rise until reaching a level that enables an effective shock by the AED.
The efficiency of carrying out a cardiopulmonary resuscitation (CPR) procedure is critical to the survival chances of the patient [4]. However, it is difficult to estimate CPR efficiency, especially outside a medical center.
Hence, efforts are made to assess CPR efficiency in order to improve the rate of successful CPR procedures. The company Cardiaid for example supplies a device that monitors pulse and breathing in the patient during CPR [5]. In another approach, International Patent Application WO2012/065167 [7] discloses sensing cyclical activities by a rescuer carrying out CPR and summarizing them, and U.S. Pat. No. 6,827,695 [8] discloses processing acceleration signals to produce an accurate estimate of the actual depth of chest compressions. These mechanical solutions try to overcome the basic problem, that vital signs are not reliable indicators as they become very chaotic and non-informative during CPR.
To summarize, as AED's are helpful in only a fraction of emergency situations, and oxygen therapy is unavailable to the non-medical care-giver, there is a pressing need for a system that can provide an integrated solution for both cardiac and respiratory emergency situations that is non-invasive and adapted to the needs of field care, and operable by minimally trained personal.
The purpose of the present invention is to provide the basically trained, semi-professional such as a life guard or police officer, with an advanced, non-invasive medical device, that supports non-invasive ventilation in an acute respiratory failure such as drowning, provides real-time feedback on CPR efficiency, optimizes the application of electric shock, and enables saving lives in a myriad of situations that were not treatable so far in an out-of-hospital field setting.
Further purposes and advantages of this invention will appear as the description proceeds.

This patent is subject to a terminal disclaimer.

System and method for providing ventilation


An optical fiber array substrate 11 has, in one surface thereof, eight V-grooves 12 for securing eight optical fibers 14 aligned in parallel to each other, and V-shaped side grooves 13 formed outside of the respective outermost V-grooves 12 located at the opposite sides of the substrate 11. The apexes of the outside ridges 12c and 12d defining the outermost V-grooves 12 are at the same height as the apexes of the inside ridges 12a and, the height of the bottom 13a of the side groove 13 is lower than that of a contact point 12e between the ridge line of the V-groove 12 and optical fiber 14.

The present invention relates to an optical fiber array substrate used in an optical device connecting a plurality of optical fibers and has securing grooves for receiving and positioning a plurality of optical fibers, and also to a method for producing the same.
In late years, there has been an increased demand for high-capacity and high-speed optical communication networks and optical devices of the optical fiber array type have been brought to attention. Typically, in such devices, a plurality of optical fibers are aligned by using a substrate having linear V-grooves, and such substrate is fabricated by a fabrication method such as press working, shaving or grinding of a plate material, or directional etching of a silicon single-crystal plate material.
However, in order to satisfy a severe dimensional accuracy required for optical fiber array substrates by means of the fabrication method as mentioned in the above, it is required to grind V-grooves precisely with high angular accuracy one by one, to finish the V-grooves with desired height and desired interval therebetween. Therefore, there are problems that the methods require many steps and are complicated, hence non-defective fraction is not increased so that costs are expensive.
In an optical fiber array substrate manufactured according to the method as described above, since the surfaces of linear V-grooves are rough and the shape of the regions between the V-grooves are too sharp, optical fibers may be damaged when mounting and also the optical fiber array substrate itself may be apt to be damaged or chipped. Therefore, it becomes concerned that the substrate may be decreased in breakage resistance to be broken. Moreover, the V-grooves, which are finished after a lot of work, may be damaged during working process or following cleaning process. Further, the bottom or top of the V-grooves may be cracked during grinding process and the like, and thereby breakage resistance of the substrate may be lowered. Thus, the optical fiber array substrate may often be broken during handling so that the yield is lowered. Therefore the production efficiency of such optical fiber array substrates is so low that they are not suitable for mass production.
Japanese Patent Laid-Open Publication No. Hei 2-139313 discloses a fabrication method of an optical fiber array substrate in which a glass base material is heated and softened to be drawn (i.e. to be drawn and formed) to a dimension of 1/10. However, since the base material actually is softened and deformed during the drawing process, it is difficult to keep the shape and to control the dimensional accuracy. As a result, the shape of the V-grooves becomes to be deformed, particularly the shape of the outside V-grooves becomes to be deformed significantly. In addition, the heights of the V-grooves become to be not uniform due to variations thereof. Thus, such optical fiber array substrates do not wear for applications requiring high accuracy. More specifically, in a substrate formed by the conventional drawing process, the surface of the base material where the V-grooves are formed is slightly elongated when heated and softened, so that the central portion of the surface is deformed to cave in the order of several micrometers. As a result of this deformation, the V-grooves in the central portion become to be lower than the V-grooves in the peripheral portion by several micrometers. When optical fibers are arranged in such V-grooves, the heights at the centers of the cores of the optical fibers become to vary by several micrometers, so that it is very difficult to fabricate a high precision substrate with V-grooves.
Further, in a conventional optical fiber array substrate 1 as shown in FIG. 9(A), outside ridges 2d and 2e defining outermost V-grooves 2a an 2b of optical fiber securing V-grooves 2 are greatly different in shape from inside ridges 2c. Therefore, when optical fibers 4 are adhered to the optical fiber array substrate 1 by the use of a thermosetting adhesive, or when they have been arranged as an optical fiber array, a difference in heat history between the outside optical fibers 4a, 4b and the inside optical fibers 4c which are supported in the V-grooves 2 is generated due to a difference in heat capacity between the outside ridges 2d, 2e and the inside ridges 2c, which will be a factor to lower the reliability of the optical fiber array.
Furthermore, in the conventional optical fiber array substrate 1 as shown in FIG. 9(B), when the optical fibers 4 are held down by a plate 5 and fixed with an adhesive 6, if the amount of the adhesive is too small, there is a problem that some of the optical fibers 4 will not be fixed completely, because of the adhesive 6 not being distributed sufficiently to the fixing portions for all of the optical fibers. On the contrary, if the amount of the adhesive is too large, the adhesive 6 will run off from the side of the substrate 1, as shown in FIG. 9(C), so that troublesome tasks such as scraping the run-off adhesive 6a or polishing the sides of the substrate 1 will be required to comply with the predetermined dimension. Therefore, there is a problem that the amount of adhesive is required to be controlled strictly.

Optical fiber array substrate and method for producing the same


An all-in-one light guide plate, a backlight apparatus employing the same, and a method of manufacturing the all-in-one light guide plate are provided. The all-in-one light guide plate has a structure in which a plurality of protrusion type refractive elements for outputting light are integrated into the light guide member. It is possible to improve optical properties by more densely arranging the refractive elements with distance from the light source.

1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to an all-in-one type light guide plate and a backlight apparatus employing the same.
2. Description of the Related Art
In general, backlight apparatuses serve to illuminate a flat display device such as a liquid crystal display device. The backlight apparatuses are mainly classified as direct light type backlight apparatuses or light guide type backlight apparatuses. The light guide type backlight apparatuses are classified as flat type backlight apparatuses or wedge type backlight apparatuses.
In the direct light type backlight apparatuses, a light source is located at the back of a light output surface, thus enabling a planar lighting. It is possible to increase brightness by arranging a plurality of light sources as compared with the light guide type backlight apparatuses. In addition, it is possible to widen an area to be illuminated. However, power consumption is also increased. In a case where the direct light type backlight apparatuses are thin, it is difficult to sufficiently diffuse light. Accordingly, a shape of a lamp is projected onto a display screen. Uniformity of brightness is considerably decreased.
The light guide type backlight apparatuses have a structure in which light is incident onto an edge of a light guide plate and output to a light output surface of a light guide plate perpendicular to the incident light. Since the light source is located at the edge or side surface of the light guide plate, the number of light sources is limited due to a length of the side surface of the light guide plate. However, it is easy to make the light guide type backlight apparatuses thin. A structure for uniformly distribute brightness over the entire light emitting surface is complex as compared with the direct light type backlight apparatuses.
The flat type backlight apparatuses are employed for monitors or a case where high brightness is required. In the flat type backlight apparatuses, light sources may be fixed to four edges of a light guide plate. In order to increase brightness by arranging a plurality of light sources, a thickness of side surfaces of the light guide plate has to be uniform.
The wedge type backlight apparatuses are employed for devices which does not use a plurality of light sources because power consumption is limited. In the wedge type backlight apparatuses, a surface of a side of a light guide plate onto which light is incident from a light source has a large width, and other surfaces of the light guide plate have a small width. Accordingly, it is possible to reduce weight of backlight apparatuses.
Light sources used for the light guide type backlight apparatuses are classified as linear or filamentary light sources or point light sources. The linear or filamentary light sources are cold cathode fluorescent lamps (CCFLs) with a structure in which electrodes of both ends are located in a tube. The point light sources are light emitting diodes (LEDs). The CCFLs can emit intensive white light. It is possible to obtain high brightness and uniformity and to design backlight apparatuses so as to illuminate a large area. The CCFLs operate by using high frequency alternating current (AC) signals and have a narrow range of operating temperature. The LEDs have lower performance in brightness and uniformity than the CCFLs. However, the LEDs operate by using direct current (DC) signals. The LEDs have a long lifetime and a wide range of operating temperature. In addition, it is possible to make backlight apparatuses thin.

All-in-one type light guide plate and backlight apparatus employing the same


A random number generator and a method for generating random number thereof are provided. The random number generator is used for generating a random sequence and includes a linear-feedback shift register (LFSR) circuit, an oscillating circuit, a delay circuit and a logic operation circuit. The LFSR circuit receives the random sequence to generate a plurality of first control signals and a plurality of second control signals. The oscillating circuit receives the first control signals to generate a random clock signal. The delay circuit receives an alternating current signal and the second control signals to generate a random delay sampling signal. The logic operation circuit receives the random clock signal and the random delay signal to generate the random sequence.

1. Field of the Invention
The invention relates to a number generator, and particularly relates to a random number generator and a method for generating random numbers thereof.
2. Description of Related Art
In the information society and the era of globalization, human beings are becoming more and more inseparable from computers and the Internet. As a result, the application of electronic transactions also becomes more convenient and popular. To improve the security of electronic transactions, using random codes to encrypt and decrypt the record of each transaction is common nowadays.
Generally speaking, a random sequence is generated by using a random number generator, and the desired random code is thus obtained by using the random sequence. In addition, the randomness of the random codes is determined by the non-repeatability of the random codes, and the randomness of the random codes determines the chance that the random codes are deciphered. Thus, how to increase the randomness of the random codes becomes a main topic in designing a random number generator.

Random number generator and method for generating random number thereof


Reducible registers are determined to optimize a sequential circuit. A screening method tests one or more sets of registers where the registers of each set are assumed to satisfy a logic condition. The tests determine if the logic condition holds. If the logic condition of a set is found to be violated, the registers may be moved to another set having a different logic condition or removed completely. The registers remaining are potentially reducible. The reducibility of the registers is verified via Boolean analysis by verifying the logic conditions of a register set for each register. If a register does not pass verification, it then may be moved to a different set having a different logic condition or removed completely. The sets that pass verification are reducible.

The present invention relates to the field of programmable devices, and the systems and methods for programming the same. Programmable devices, such as FPGAs, typically includes thousands of programmable logic cells that use combinations of logic gates and/or look-up tables to perform logic operations. Programmable devices also include a number of functional blocks having specialized logic devices adapted to specific logic operations, such as adders, multiply and accumulate circuits, phase-locked loops, and memory. The logic cells and functional blocks are interconnected with a configurable switching circuit. The configurable switching circuit selectively routes connections between the logic cells and functional blocks. By configuring the combination of logic cells, functional blocks, and the switching circuit, a programmable device can be adapted to perform virtually any type of information processing function.
A typical process for determining the configuration of a programmable device, referred to compilation, starts with an extraction phase, followed by a logic synthesis phase, a fitting phase, and an assembly phase. The extraction phase takes a user design, typically expressed as a netlist in a hardware description language such as Verilog or VHDL, and produces a set of logic gates implementing the user design. In the logic synthesis phase, the set of logic gates is permuted over the hardware architecture of the programmable device in order to match elements of the user design with corresponding portions of the programmable device. The fitting phase assigns the various portions of the user design to specific logic cells and functional blocks (sometimes referred to as placement) and determines the configuration of the configurable switching circuit used to route signals between these logic cells and functional blocks (sometimes referred to as routing), taking care to satisfy the user timing constraints as much as possible. In the assembly phase, a configuration file defining the programmable device configuration implementing the user design is created. The programmable device configuration can then be loaded into a programmable device to implement the user design. Programmable devices can be configured with the configuration during or after manufacturing.
One of the substantial challenges of the logic synthesis phase is the optimal representation of the user design of the sequential circuit. FIG. 1 illustrates an example sequential circuit. In a sequential circuit 100, there exists combinational logic 110, such as AND, OR, and other types of gates, and registers 120. Registers store the current state of the sequential circuit 100. The next state of the sequential circuit 100 may depend on the current state and/or on inputs to the circuit. Often, the logic synthesis phase strives to implement portions of the user design with as few registers and combinational logic gates as possible in order to get a more efficient design or implementation. The search for reducible registers is important for this goal of reducing the number of registers and logic elements.
Examples of reducible registers are "stuck-at" or "duplicate" registers. In some circuits, a register value may never change regardless of the inputs or the current state of the sequential circuit, and thus the register is "stuck-at" the value with which it powers up. Other register values are "duplicates," if they are set to identical values at power up and continue to carry identical values for every possible current state and input combination to the sequential circuit. Registers that have opposite values and continue to carry opposite values are also considered "duplicates." Reducible registers and associated logic can be removed to simplify the sequential circuit.
Some optimization methods use Boolean analysis to identify reducible registers. Although robust and accurate, these methods are quite slow when the number of inputs and registers is large. Other methods use random simulation methods to test the functional equivalence of hardware designs. These random simulation methods randomly select input values to test the outputs of different circuits. To verify functional equivalence, the random simulation methods require an exhaustive search of all input values to avoid leaving large portions of a sequential circuit untested. Additionally, these prior "functionally equivalent" approaches are limited to evaluating the equivalence of combinational circuits already identified for optimization. They do not identify possible areas of a circuit to be optimized.
It is therefore desirable to have a fast and efficient system and method to optimize a sequential circuit. It is further desirable for the system and method to quickly screen out registers that are not likely to be reducible. It is also desirable for the system and method to efficiently identify and verify reducible registers given a user specified sequential circuit.


A method, system, and data structure are provided which facilitate matrix multiplication with advantageous computational efficiency. The invention, as variously implemented as a processing system, method, or data structure in a recording medium such as a memory, has applicability to numerous fields, including linear programming, where a great deal of multiplication of large, sparse matrices is performed. The method of the invention includes the steps of creating a first submatrix block from non-zero terms of a sparse matrix, such that all of the terms within a given column of the submatrix block are form a respective column of the sparse matrix, creating a corresponding second index submatrix block of the same dimensions as the first block, such that each term of the second block identifies the position of the corresponding term of the first block within the sparse matrix, in terms of a row and column index. Finally, the method includes reordering terms of the first and second blocks correspondingly, as necessary to produce a final configuration within the first and second blocks such that all of the row indices within any given row of the second block are distinct.

As an introduction to the types of issues which arise in the application of processing systems to matrix processing, a discussion of linear programming will be given, including a discussion of what techniques are used for solving linear programming problems and of what role matrix processing plays in those techniques. From this discussion, it will be evident how the method of the invention is applicable to improve matrix processing performance.
The field of linear programming came into existence in the years following World War II, in which various types of logistical problems, many extremely complex and involving up to thousands of variables, needed to be solved as cost-efficiently as possible.
A typical problem might be one of supplying various types of goods from a number of distribution sites to a number of destinations. Each destination has certain requirements regarding how many of each type of goods it needs to have on hand. For a given type of goods at a given location, a certain cost per unit shipped is associated with each distribution point. Generally, the cost is related to the distance between the distribution point and the destination, or the mode of transportation which must be used in shipping the goods. Also, there may be constraints on the quantity of goods shipped. For instance, a given distribution site might have a limited quantity of a certain type of goods on hand. Thus, a nearby destination having a greater demand for those goods is required to ship some of its requirements from a more distant, more costly, distribution site. Also, since linear programming problems often arise out of "real-world" situations, zero is often a lower bound on the value of a variable. That is, the quantity of goods shipped from a given source to a given destination will likely have zero as a realistic lower bound.
The problem, then, is to find values for the quantities of each type of goods shipped from each distribution point to each destination, such that the total cost required for all the shipments is minimized, but all of the destinations are supplied with their requirements of all types of goods. This problem, as with essentially all linear programming problems, is expressed mathematically in the following general form: ##EQU1## subject to: EQU Ax=b (2)
where EQU L.sub.j .ltoreq.x.sub.j .ltoreq.U.sub.j ( 3)
That is, find a vector of x values such that the sum of products of the x values and a set of coefficients is minimized, given a set of constraints on the x values.
The first of these three expressions may be through of as a cost function. In the example given above, the variables x.sub.j represent the quantities of goods shipped, and the variables c.sub.j represent the costs per unit associated with shipping the goods. Thus, each term of the sum is a total cost for shipping one type of goods from one distribution point to one destination. The sum of all such terms is the grand total cost for all shipments. It will be seen, then, that minimizing this grand total cost of all such shipments is the basic objective of a linear programming problem.
The constraint Ax=b defines the "ground rules" for the linear programming problem under which the cost is to be minimized. In this expression, b is a vector of constants, in which each constant is the total quantity of one of the types of goods required by the destination. The A matrix and the b vector represent information such as the requirements of each location for each type of goods, etc. Note that Ax=b may also be a set of inequalities, such as Ax.ltoreq.b, etc.
Finally, the last expression represents constraints, if any, on the quantities of goods shipped from a given distribution point. In many linear programming problems, the lower bound L.sub.j is zero. As described above, the upper bound U.sub.j is a constraint, which may limit the maximum value for the quantity of a given type of goods shipped from a given location, if that is all there is on hand at that location.
Ax=b represents a system of linear equations, where x is a vector of variables, and A is a two-dimensional array of coefficients. Since A, x, and b are vectors or matrices, it will be seen that the expression Ax=b is s matrix multiplication problem. It will thus be seen that matrix processing capability is fundamental to solving linear programming problems.
In practice, the coefficient matrix A is usually sparse. A matrix is said to be "sparse" if a large portion of its terms are zero.
Given a system of n equations in n variables, it is possible to solve the system of equations to obtain unique values for the variables, if such unique values exist. However, in most realistic linear programming problems, the number of variables greatly exceeds the number of equations. Thus, there are a large number of possible solutions to such a system of equations. Because of this, it is possible to attempt to find one of the possible solutions which minimizes the total cost.
If the variables x.sub.j are visualized as defining an n-dimensional solution space for the linear programming problem, then the range of possible solutions can be represented as an n-dimensional polyhedron within that solution space. Because the equations defined by Ax=b are linear, the faces of the solution polyhedron are planar. Faces of the solution polyhedron are defined by the limiting values of various ones of the variables x.sub.j. It can be proven that the minimum cost is given by a solution represented by one of the vertices of the polyhedron.
The concept of a solution polyhedron in a solution space is a key to conceptualizing the different strategies for solving linear programming problems, which will now be presented.
The Simplex Method
The classic text by Dantzig, "Linear Programming and Extensions," Princeton University Press, Princeton, N.J. (1963), teaches a method, called the "simplex method", for solving a linear programming problem, i.e., finding values for the vector of x variables such that the cost is minimized. In the simplex method, a solution represented by one of the vertices of the solution polyhedron is selected, more or less at random. Then, moves are made in a sequence from one vertex to another, each move decreasing the total cost, until finally a vertex is reached from which no additional movement can reduce the cost any further. This final vertex is the solution to the linear programming problem.
The simplex method is executed as follows: A group of variables equal to the number of equations are selected, more or less at random, and are designated "basic variables." The remaining variables are called "nonbasic" or "independent" variables. The independent variables are set to feasible values, i.e., values within the range defined by the upper and lower limits given in the above expression. Since the lower limit L.sub.j is often 0, feasibility generally means that the variables have nonnegative values.
Using algebraic techniques similar to those used in solving n equations in n variables, i.e., adding linear combinations of the equations, the system of linear equations is placed into "canonical form," in which each equation has a coefficient 1 for one of the basic variables, and coefficients 0 for all the other basic variables. Thus, placing the equations in canonical form is equivalent to solving for the basic variables. This solution, if it is feasible, represents one of the vertices of the solution polyhedron.
Next, a better solution is sought as follows: The value of one of the independent variables is varied. Varying the value of the independent variable has the effect of changing the values of other variables. If varying the independent variable reduces the total cost, that independent variable is varied in value until one of the basic variables reaches a limiting value, such as zero. That basic variable is now replaced by the independent variable whose value had been changed. The values for the resulting new set of basic variables define another vertex of the solution polyhedron, connected to the first vertex by an edge. Varying the value of the independent variable had the effect of moving along an edge of the solution polyhedron which runs from the first vertex to the new vertex.
The process just described is repeated, moving from vertex to vertex, until no further change to any of the independent variables results in a cost reduction. At this point, the values of the basic and independent variables define the optimal solution to the linear programming problem, and the simplex method has been completed.
Since there are often on the order of thousands of variables in a realistic linear programming problem, solutions are typically calculated on computers. Because of the large numbers of calculations involved in matrix algebra, and the large number of iterations required for a technique such as the simplex method, computational efficiency is an important objective in a computer-implemented linear programming solver.
In particular, an implementation of the simplex method involves certain specific types of matrix calculations. First, in the expression Ax=b, Ax is broken up into two terms, i.e., two matrix products, representing basic variables x.sub.b and independent variables x.sub.n, as follows: EQU Ax=Bx.sub.b +Nx.sub.n =b (4)
This expression is then solved for x.sub.b as follows: EQU x.sub.b =B.sup.-1 b-B.sup.-1 Nx.sub.n ( 5)
The cost z associated with the selected values for the variables is given b y EQU z=c.sup.T.sub.B x.sub.B +C.sup.T.sub.N x.sub.N ( 6)
It is necessary to use the matrix transposes c.sup.T.sub.b and c.sup.T.sub.n of the basic and independent portions of the cost coefficient matrix for these matrix multiplication expressions to be in proper form. Therefore, a cost differential d.sub.j which is associated with changing the value of one of the independent variables associated with the j-th column of the N matrix is given by the expression EQU d.sub.j =c.sub.j -c.sup.T.sub.B B.sup.-1 a.sub.j ( 7)
where c.sub.j is the cost, absent the change of value of the independent variable, a.sub.j is the j-th column of N, and B.sup.-1 is the inverse matrix of B. For a change of value of an independent variable to produce an overall reduction in cost, d.sub.j should have a value less than zero.
The above expression is calculated many times during the course of solving a linear programming problem. Therefore, the matrix product c.sup.T.sub.B B.sup.-1, which is a one-dimensional vector, is designated as .pi..sup.T, and referred to as the "shadow prices" or "pi values." During the course of the simplex method, the matrix product .pi..sup.T A, or .pi..sup.T a.sub.j for individual columns of the matrix A, is calculated many times. The expression .pi..sup.T A is referred to as "multiplication on the left," referring to the position of the matrix .pi..sup.T to be multiplied with the coefficient matrix A. This calculation is made for every iteration of the simplex method, to determine whether the change in value of an independent variable is reducing the total cost. For these calculations, which may number in the thousands, A remains constant, but the pi values change as different variables are swapped in and out of the set of basic variables.
A different matrix calculation is made, following each iteration, to check for the feasibility of the solution. The vector of solutions x is multiplied by the coefficient matrix, to evaluate Ax=b. This is referred to as "multiplication on the right," again referring to the position of the vector to be multiplied with the coefficient matrix A. In the simplex method, multiplication on the right is executed much less frequently than multiplication on the left. Accordingly, in vector processing implementations of linear programming software, optimization for multiplication on the left has produced good computational efficiency for the simplex method. While this optimization decreases the efficiency of multiplication on the right, overall computational efficiency is not greatly reduced, since multiplication on the right is performed relatively infrequently.
Interior Point Methods
More recently, alternative methods for solving linear programming problems have been explored. These other methods have been referred to as "interior point" methods, because they can be characterized as moving through the interior of the solution polyhedron. This is in contrast with the simplex method, in which motion is only along the outer edges of the solution polyhedron.
Several different interior point methods are discussed in detail in Forrest and Tomlin, "Implementing Interior Point Linear Programming Methods in the Optimization Subroutine Library," IBM Systems Journal, Vol. 31, No. 1, 1992. One class of interior point methods, for instance, is called barrier methods. In a barrier method, non-linearities are introduced which prevent the limits from being violated. Then, calculus-based methods are used for the minimization. For example, in a logarithmic barrier method, the problem is to find values for the variables x.sub.j which minimize ##EQU2## subject to: EQU Ax=b (9)
where EQU L.sub.j .ltoreq.x.sub.j .ltoreq.U.sub.j ( 10)
In the above expressions, .mu..fwdarw.0 and .mu.>0. Because .mu. is positive, the logarithm terms become large as the variable approaches the limit. However, since .mu. tends toward zero, the logarithm terms are small, and do not greatly change the result from what it would be if only the cost terms were summed. Since the logarithmic terms of the sum are not defined for values outside the upper and lower limiting values, the bounds cannot be violated.
In essence, solving such a problem involves taking a series of steps from an initially selected solution, each step having a given step length, and each step being taken in a direction, through the solution polyhedron, of reduced cost. The major computational burden of each step of the interior point method is a gradient projection, which is solved as a least-squares problem. The solution of the least-squares problem is a vector change. For the least-squares solution, pi values and reduced costs are updated in a manner similar to that described in connection with the simplex method.
In particular, the least-squares calculation involves multiplication on the right. The matrix product Ax is computed a much greater number of times in interior point methods than in the simplex method.
Considerations that Affect Computational Efficiency
From the foregoing, it will be seen that, whether the simplex method or an interior point method is used to solve a linear programming problem, there will be a great many matrix multiplications involving the coefficient matrix A. Matrix multiplication is generally implemented on a processor having vector processing capability as vector multiplication of rows and/or columns. Multiplications both on the left and on the right are used. Frequently, the A matrix is sparse, i.e., a large number of the terms of the A matrix have the value zero. Thus, computational efficiency is improved by reducing the number of multiplications involving zero terms.
In Forrest and Tomlin, "Vector Processing in Simplex and Interior Methods for Linear Programming", 22 Annals of Operations Research 71-100 (1990)2!, a method is employed for storing coefficients in computer memory for convenient access and efficient execution of multiplication on the left. Columns of the A matrix having large numbers of non-zero terms are stored separately for vectorization. Columns having relatively few non-zero terms are stored in blocks. A second block of memory contains indices, each index corresponding with one of the non-zero terms stored in the block, and indicating which position in the column of the A matrix the term occupied. The cost reduction is then calculated, using a vector processor, by reading a vector of indices from the second block, obtaining a vector of pi values, selecting each pi value for the vector based on the value of the corresponding index. Finally, the scalar product of the pi value vector and the corresponding row of the first block is added to a cost reduction value. This process is repeated for each row of the first block. Because this method involves multiplying rows of the A matrix terms, computational efficiency is achieved by storing the terms in memory row-wise.
Since the most frequently executed matrix multiplication in the simplex method is that on the left, the above data structure works well. However, since the advent of interior point methods, it has been common practice to follow interior point optimization by iterations of the simplex (or a simplex-like) method. For the newer interior point methods, where multiplication on the right (Ax) takes place more frequently, the above data structure is not well suited. Therefore, to accommodate the newer interior point methods, it is desirable to find a way of utilizing the above-described data structure efficiently to vectorize multiplication on the right.

Processing system and method for performing sparse matrix multiplication by reordering vector blocks

International Business Machines Corporation


A method of producing calcium chloride granules of a specific size from a calcium chloride and water solution in a completely closed environment by controlling the rate of fall of a specific size of solution droplet through an up-current of hot, dry gas.

This application is a divisional application based upon the application entitled "Process for Manufacturing Calcium Chloride Salt" Ser. No. 08/002,062, filed by Lucas James on Jan. 8, 1993, pending. Calcium chloride salt is a well known and widely used chemical. It is usually used in a granulated state for a variety of purposes ranging from food preparation to highway de-icing. The design and process disclosed herein provides for the production of this important chemical in a more efficient and economical manner.

Calcium chloride salt manufacturing process


A thermoelectric generator (TEG) and a method of fabricating the TEG are described. The TEG is designed so that parasitic thermal resistance of air and height of legs of thermocouples forming a thermopile can be varied and optimized independently. The TEG includes a micromachined thermopile sandwiched in between a hot and a cold plate and at least one spacer in between the thermopile and the hot and/or cold plate. The TEG fabrication includes fabricating the thermopiles, a rim, and the cold plate.

A TEG uses a temperature difference occurring between a hot or warm object (i.e., a heat source) and the object's colder surrounding (i.e., a heat sink) and transforms a consequential heat flow into useful electrical power. The necessary heat can be produced by radioactive materials, such as in space applications, or by sources available in the ambient, such as standard cooling/heating systems, pipe lines including pipe lines with warm waste water, surfaces of engines, parts of machines and buildings, warm-blooded animals, or human beings. Natural temperature gradients can be used, as well as geothermal temperature gradients, temperature gradients on ambient objects when naturally cooling/heating at night/day, temperature differences between a cold river and a warm shore or between a warm river and ice on it, between ice on water and surrounding air, and so on.
There is an increasing interest in miniaturized TEGs, which could replace batteries in consumer electronic products operating at low power. For example, TEGs mounted in a wristwatch have been used to generate electricity from wasted human heat, thus providing a power source for the watch itself. See M. Kishi, H. Nemoto, T. Hamao, M. Yamamoto, S. Sudou, M. Mandai and S. Yamamoto in 'Micro-Thermoelectric Modules and Their Application to Wristwatches as an Energy Source', Proceedings ICT'99 18th Int. Conference on Thermoelectrics, p. 301-307, 1999.
Recently, MEMS technology has also been used to fabricate miniaturized TEGs, as described by M. Strasser, R. Aigner, C. Lauterbach, T. F. Sturm, M. Franosh and G. Wachutka in 'Micromachined CMOS Thermoelectric Generators as On-chip Power Supply', Transducers '03. 12th International Conference on Solid State Sensors, Actuators and Microsystems, p. 45-48, 2003; by A. Jacquot, W. L. Liu, G. Chen, J.-P. Fleurial, A. Dausher, B. Lenoir in 'Fabrication and modeling of an in-plane thermoelectric micro-generator', Proceedings ICT '02. 21st International Conference on Thermoelectrics, p. 561-564, 2002; and by H. Böttner, A. Schubert, K. H. Schlereth, D. Eberhard, A. Gavrikov, M. Jägle, G. Kühner, C. Künzel, J. Nurnur and G. Plesher in 'New Thermoelectric Components using Micro-System-Technologies', ETS 2001-6th European Workshop on Thermoelectrics, 2001.
TEGs can be characterized by an electrical and a thermal resistance, and by both voltage and power generated per unit temperature difference between the hot and cold sides of the TEG. The relative importance of these factors depends on the specific application. In general, electrical resistance should be low, and voltage or power output should be maximized, in particular, in applications with a small temperature difference (i.e., a few degrees C. or few tens of degrees C.). If a fixed temperature difference is imposed at the boundaries of the TEG by, for example, means of hot and cold plates, the value of thermal resistance is not crucial. Contrary thereto, if the boundary condition is a fixed or limited heat flow through the device, then the thermal resistance, on one hand, has to be large enough to generate a reasonable temperature drop over the device, but on the other hand, has to be small enough to avoid variations in the heat flow.
The basic element of a TEG is a thermocouple 10 (FIG. 1). An example of a thermocouple 10 includes a first leg 11 and a second leg 12 formed with two different thermoelectric materials, such as the same but opposite doped semiconductor material, and exhibiting low thermal conductance and low electrical resistance. For example, the legs 11, 12 could be formed from BiTe. If the first leg 11 is formed of n-type BiTe, then the second leg 12 is formed of p-type BiTe, and vice versa. The legs 11, 12 are connected by a conductive interconnect, such as a metal layer interconnect 13, which forms a low-resistance ohmic contact to the semiconductor legs 11, 12.
In FIG. 2, a TEG 20 including a thermopile 21 having a plurality of, and preferably a large number, of thermocouples 10 is shown. The thermopile 21 is sandwiched between a hot plate 22 and a cold plate 23. The hot plate 22 and the cold plate 23 are made of materials having a large thermal conductivity, so that the thermal conductance of the plates 22, 23 is much larger (at least a factor of ten) than the total thermal conductance of the thermopile 21.
Hereinafter, the difference between classical and micromachined thermoelectric generators is discussed. Although the geometrical arrangement of the basic elements or thermocouples 10 composing the TEG 20 may be different, such as the in-plane position of the thermocouples 10 (i.e., parallel to the plates 22, 23), in classical and micromachined TEGs 20 the schemes of FIG. 1 and FIG. 2 hold for both. The difference between the two implementations is quantitative.
Typical dimensions of legs 11, 12 for a classical TEG 20 are on the order of a few millimeters for the height h and on the order of hundreds of micrometers to 1 millimeter for the square root of the cross-section, which in the further description will be referred to as lateral size a. The aspect ratio of the legs 11, 12, which is determined by height h over lateral size a (h/a), may be in the order of 1 to 3 in case of a classical TEG 20. The aspect ratio for a TEG produced by Seiko, i.e., a classical TEG, is 7.5. The smallest thermopiles 10 currently available on the market (Thermix; Kiev, Ukraine) demonstrate an aspect ratio of less than 5. For micromachined TEGs 20, the lateral size a is on the order of a few micrometer, and the aspect ratio h/a can be larger than in the case of a classical TEG (e.g., more than 10).
In case of a constant or limited heat flow through the TEG 20, the output voltage and power depend on the number of thermocouples 10 comprised in it, and it can easily be shown that the maximum power is obtained when the heat flow through the thermoelectric material is equal to the "parasitic" heat flow through the air, including radiation heat exchange.
In order to give numerical examples, the TEG device area is fixed to 1 cm2 and the heat flow to 18.5 mW/cm2, which is a typical heat flow from a human body skin. Furthermore, it is assumed that the legs 11, 12 of the thermocouples 10 are respectively made of n-type and p-type BiTe, and that the TEG 20 operates in air. The thermal resistance of the metal layer interconnect 13 and the electrical resistance of the contacts between the legs 11, 12 of the thermocouple 10 and the metal layer interconnect 13 are considered to be negligible. Values used for the calculations are reported in Table I.
TABLE IParameters used for the calculation of TEG performanceParametersValueThermal conductivity of BiTe, W K−1m−1 1.5Thermal conductivity of air, W K−1m−1 0.026Resistivity of BiTe (n and p), Ωm 10−5Input heat flow, Wm−2185
First, a classical TEG 20 is considered. Dimensions chosen for the legs 11, 12 are close to those of the best currently available commercial devices, i.e., a lateral size a of 250 μm and a height h of 750 μm. In FIG. 3, the output power Pout (full line) and output voltage Vout (dashed line) for such a TEG 20 are illustrated as a function of the number of thermocouples 10. In correspondence of the maximum power, the output voltage is low (i.e., 15 mV) as can be seen from FIG. 3, which is well below the level necessary for powering standard electronics. Typical voltages are 3 to 5 V. It is well known in the art to up-convert 800 mV to these values; however, it is much more difficult and less efficient to reach these values starting from 300 mV or less.
As can be seen in FIG. 4, the temperature drop corresponding to the maximum power is about 2.3 K. The performance of the TEG 20 can be improved by increasing the aspect ratio of the legs 11, 12. For example, as described by M. Kishi, H. Nemoto, T. Hamao, M. Yamamoto, S. Sudou, M. Mandai and S. Yamamoto in 'Micro-Thermoelectric Modules and Their Application to Wristwatches as an Energy Source', Proceedings ICT'99 18th Int. Conference on Thermoelectrics, p. 301-307, 1999, the lateral size a and height h of the legs 11, 12 are respectively 80 μm and 600 μm. In this case, a 0.4 cm2 TEG (10 units of 2×2 mm size are used in the watch) gives a voltage of 0.25 V when it delivers a maximum power of about 20 μW. Although the aspect ratio, h/a, of the thermoelectric legs 11, 12 of 7.5 (=600 μm/80 μm) in the above example represents a current technological limit, the voltage obtained is still of impractical use. It can thus be concluded that the low output voltage is a main restriction to a wide use of the TEGs 20 operated in a low heat flow mode.
Next, a micromachined TEG 20 is considered which comprises legs with a thickness of 0.5 μm, a width of 1 μm and a height of 5 μm. In FIG. 5, the output power (∘) and voltage (▴) are shown as a function of the number of thermocouples 10. The power is limited to only 0.11 μW. This maximal power is achieved for a TEG 20 having about 1.8 million thermocouples 10 (see FIG. 5). For the same number of thermocouples 10, a voltage of about 3V is obtained. In FIG. 6, the temperature difference (∘) and the electrical resistance (▴) of a micromachined TEG 20 are reported. The temperature difference (∘) of the TEG 20 at the maximal power is limited to 18 mK. The corresponding thermal resistance, which is determined by Rth=ΔT/P (with ΔT=a temperature drop and P the heat flow) is 1 K/W, which is not enough to obtain a good temperature drop.
The above results are confirmed by experimental data. For example, as described by M. Strasser, R. Aigner, C. Lauterbach, T. F. Sturm, M. Franosh and G. Wachutka in 'Micromachined CMOS Thermoelectric Generators as On-chip Power Supply', Transducers '03, 12th International Conference on Solid State Sensors, Actuators and Microsystems, p. 45-48, 2003, a large number of thermocouples 10 has been fabricated and a large output voltage is obtained. H. Böttner, A. Schubert, K. H. Schlereth, D. Eberhard, A. Gavrikov, M. Jägle, G. Kühner, C. Künzel, J. Nurnur and G. Plesher point out in 'New Thermoelectric Components using Micro-System-Technologies', ETS 2001—6th European Workshop on Thermoelectrics, 2001, that both the temperature drop and the output power are low in micromachined TEGs 20. For example, micromachined TEGs produced by Infineon show about 10 mK temperature difference between the hot and the cold side (H. Böttner in 'Thermoelectric Micro Devices: Current State, Recent Developments and future Aspects for Technological Progress and Applications', International Conference on Thermoelectrics, 2002). However, experimental conditions have not been published.
For the number of thermocouples 10 at which the maximum power is achieved (see FIG. 5), the electrical resistance approaches 0.4 GΩ (see FIG. 6), which is a too high of a value for a generator powering electronic devices or battery chargers. It can be seen that the optimal number of thermocouples 10 is about 1.8 million, because in that case the thermal resistance of air is equal to the thermal resistance of thermopile or in series connected thermocouples 10, so the output power is maximized. This large number of thermocouples 10 can be fabricated if one thermocouple 10 occupies a square of only about 7×7 μm2 size. This is a difficult but not impossible task. The large number of thermocouples 10 furthermore has the drawback of increased probability of getting a non-functioning device, since thermocouples 10 are electrically coupled in series. Hence, the failure of one thermocouple 10 will cause the failure of the whole TEG 20. This drawback potentially leads to a dramatically decreased yield of good devices and increased cost of manufacturing.
In order to understand the difference in behavior between a classical and a micromachined TEG 20, a thermal analysis is performed of the TEG configuration as illustrated in FIG. 2. Analytical results are reported and discussed hereinafter. The number of thermocouples n, the temperature drop ΔT, and the output voltage Vout at a maximal power Pout are given by the expressions (1) to (4):
                              n          =                                                                      G                  air                                                h                                                              g                  te                                                                  a                  2                                                      =                                          Ag                a                                                              g                  te                                                                  a                  2                                                                    ,                            (        1        )                                                      P            out                    =                                                    1                16                                                          S                2                                                                                W                    u                    2                                                                          A                    2                                                                                g                    te                                                      ρ                                                                          1                                  G                  air                                                      =                                          1                16                                                          S                2                                                                                W                    u                    2                                                      A                                                                      g                    te                                                      ρ                                                                          h                                  g                  a                                                                    ,                            (        2        )                                                      Δ                                                                          T                    =                                                                      W                  u                                                A                                            2                                                  G                  air                                                      =                                                            W                  u                                                h                                            2                                                  g                  a                                                                    ,                            (        3        )                                          V          =                                                                      W                  u                                                AS                                            g                te                                                                h                              a                2                                                    ,                            (        4        )            wherein                A is the area of the hot/cold plate 22, 23,        a is the lateral size of the legs 11, 12,        h is the height of the legs 11, 12,        ga is the thermal conductivity of air,        gte is the thermal conductivity of the thermoelectric material the legs 11, 12 are made of,        ρ is the resistivity of the thermoelectric material the legs 11, 12 are made of,        S is the Seebeck coefficient (assumed to be equal for both legs 11, 12),        Gair is the thermal conductance of the air between the hot plate 22 and the cold plate 23, and        Wu is heat flow per unit area.
Equations (1) and (2) show that, at the maximum power condition, the number n of necessary thermocouples and the output voltage depends on the ratio h/a2, which is much larger for a micromachined TEG than for a classical one. It can then be stated that micromachined thermoelectric generators require a larger number of thermocouples and deliver power at a larger voltage. The power Pout and temperature difference ΔT (respectively, equations (2) and (3)) depend mainly on the thermal conductance Gair of the air between hot plate and the cold plate. Since this thermal conductance Gair is larger for micromachined thermopiles, the temperature drop ΔT and power Pout are low for these devices.

Method of manufacturing a thermoelectric generator and thermoelectric generator thus obtained


A method and apparatus that prevents premature drying of a layer of a water-based coating composition on a substrate are disclosed.

Investigators have developed coating compositions that are free of organic solvents, or at least incorporate a minimum amount of organic solvents, in order to avoid the environmental, toxicological, and safety problems associated with organic solvents. As a result, water-based coating compositions, including pigmented coatings, are being used in more and varied applications. In particular, water-based coating compositions, including solutions, emulsions, and dispersions, have properties that make them suitable for application to a variety of substrates, both metal and nonmetal.
However, water-based coating compositions have different application characteristics from solvent-based coating compositions. For example, many water-based coating compositions exhibit a poor flow during roller application, which results in stripes (i.e., zones of uneven film thickness) appearing during, and after, application of the coating composition to the substrate. The stripes typically remain after the curing, or air drying, of the coating composition layer. The substrate, therefore, has a coating of uneven thickness which can adversely affect the esthetics of the coated substrate and/or the barrier properties of the coating.
In order to demonstrate good flow, a coating composition applied in a roller coating application must remain in the liquid phase for a sufficient time to form a uniform layer of the coating composition on the substrate. With solvent-based coating compositions, the drying time can be adjusted, or optimized, by a judicious selection of specific solvents. In a very limited way, drying time adjustments also can be done with water-based coating compositions. However, such adjustments are not desirable and are of very limited benefit for water-based coating compositions.
It has been observed that water-based coating compositions exhibit flow problems because the coating composition dries too quickly, i.e., before the desired curing of the coating composition on the surface of the coated substrate. Accordingly, spreading the coating composition over the entire surface of the substrate to provide a coating layer of uniform thickness is hindered. For example, when a water-based coating composition is applied by a spreading blade onto a substrate, only incompletely merged strip patterns are formed, and the desired coating layer does not coat the substrate evenly.
Additional problems result because the water-based coating composition also has a tendency to dry on the application device, such that uniformity of the coating on the substrate is adversely affected. In direct, gravure, or reverse roll coating applications, the formation of a skin is evidence of drying of the coating composition on the roll surface and in the edge zones. In addition, in spray applications, drying of the coating composition produces clogged spray nozzles. Troublesome and time-consuming cleaning operations then are necessary, which adversely affect the continuous operation of the application equipment.
These problems result because the physical properties of a water-based coating composition are closely related to the properties of water. As stated above, water-based coating compositions typically have poor flow properties during roller coating application. There are several reasons for poor flow, such as high surface tension, rheological properties, and the relatively fast drying of the water-based coating compositions. An important reason for the relatively fast drying speed of water-based coating compositions is the fast evaporation rate of water, or water azeotropes, compared to solvent-based coating compositions.
It is possible to prevent or retard the undesirable, premature drying of water-based coating compositions by the addition of solvents, but this negates the primary objective of a water-based coating composition, i.e., avoiding the use of organic solvents. Accordingly, the present invention is directed to a method and apparatus that prevents premature drying of water-based coating compositions that are applied to the surface of a substrate.

Method and apparatus for applying a water-based coating composition to a substrate


The present invention relates to a horn antenna device. The horn antenna device has a step-shaped signal feed-in apparatus and a conical horn antenna. The step-shaped signal feed-in apparatus has a stepped body having multiple stairs and a connecting pin. The stepped body is adapted to radiate electromagnetic waves and receive a reflection of the electromagnetic waves. According to the structure of the step-shaped signal feed-in apparatus of the invention, the resonating modes are easy to be determined. The directivity and the signal-to-noise rate are improved. In addition, the connecting pin is directly connected to the stairs for improving the signal stability of the horn antenna device.

1. Field of the Invention
The present invention relates to an antenna device, and more particularly to a horn antenna device with a step-shaped signal feed-in apparatus for focusing electromagnetic waves.
2. Description of Related Art
In order to measure an object level, such as water level in a reservoir or mineral stockpiles of a quarry, a radar level meter is developed to measure the object level.
The radar level meter can be installed at a position far from an object. The radar level meter mainly comprises a circuit board and an antenna. The circuit board generates electromagnetic waves of FMCW (frequency modulated continuous waves) and radiates the electromagnetic waves toward the object through the antenna. The electromagnetic waves are then reflected from a surface of the object when the electromagnetic waves reach the object. Afterward, the circuit board can receive a reflection of the electromagnetic waves from the antenna.
The circuit board has a controller. The controller calculates a frequency difference and a time difference between the reflection and the electromagnetic waves emitted from the antenna. When the controller obtains the frequency difference and the time difference, the controller calculates a distance between the radar level meter and the surface of the object or further calculates an object level according to the distance.
With reference to FIG. 9, a conventional level measuring device is disclosed. The measuring device comprises a radar level meter 80 and a waveguide apparatus 90. The waveguide apparatus 90 has a body 91, a medium converter 92 and a feed-in connector 93. The body 91 has an opening 911, a hole 912 and a space 913. The space 913 communicates with the opening 911 and the hole 912. The medium converter 92 is conical in shape and has a cone point 921 and a bottom end 922 distal to the cone point 921. The bottom end 922 of the medium converter 92 is mounted in the opening 911 of the body 91. The feed-in connector 93 can be an SMA connector or an SMP connector and is inserted in the hole 912. The feed-in connector 93 has a probe 931 extending into the space 913 of the body 91.
The radar level meter 80 is connected to an end of the waveguide apparatus 90 distal to the probe 931. The radar level meter 80 feeds high frequency electromagnetic waves into the space 913 of the body 91 through the feed-in connector 93. The medium convertor 92 thus radiates the electromagnetic waves outward. The medium converter 92 is used for matching impedance. The medium converter 92 converts a spherical wave to a plane wave beneficial for transmitting and receiving wireless signals.
However, the electromagnetic waves generated from the feed-in connector 93 are fed in the medium converter 92 via the space 913. The electromagnetic waves are not directly fed in the medium converter 92. As such, the resonating modes, such as TE mode and TM mode, of the electromagnetic waves are difficult to be determined. Correspondingly, it is complicated and highly time-consuming to design the structures of the waveguide apparatus 90. Assembling problems, such as the feed-in connector 93 not exactly mounted in the hole 912 and the medium convertor 92 not securely mounted to the body 91, result in inadequate stability.
With reference of FIG. 10, a reflection coefficient (S11) chart of the electromagnetic waves generated from the waveguide apparatus 90 is disclosed. The return loss at 9.0 (GHz) is −12.5 (dB). The return loss at 9.5 (GHz) is −15.846 (dB). The return loss at 10 (GHz) is −13.285 (dB). When the return loss is lower than −10 (dB), a band width is only 1.75 (GHz), wherein 10.5 (GHz)−8.75 (GHz)=1.75 (GHz). A radiation pattern of the medium convertor 92 is easily affected and thus lowers the signal quality.

Horn antenna device and step-shaped signal feed-in apparatus thereof


The invention is a beverage cup tote to be carried on the forearm or with the hand. The construct has an enlarged first end attached with bridge section to an enlarged second end. There is a first hole in the first enlarged end, and a second hole in a second enlarged end. The holes may be rectangular or round to receive typical food containers or beverage cups. The bridge section has either symmetrical or asymmetrical quarter circle trimmings. A pair of constructs maybe affixed with each other with a pin clip, glue, or staples to produce a generally X shaped combination construct. The beverage cup totes may be manufactured as a combination construct by the manufacturer to produce a strengthened unit, or manufactured as a generally X shaped combination construct unit with cup openings on each branch. The process of using the invention is described.

Often friends and associates attend sporting events or picnics in small groups. At such events, ordinarily one person will obtain drinks and food from the concession stand for one or two people in addition to his own food and drinks. Thus a person obtaining the drinks and food will be required to carry multiple drinks and possibly one or more plates of food. This can be quite inconvenient. The spilling and wasting of the newly purchased food is common. While many food items can be packed in paper bags it is relatively difficult to safely transport soft drinks even with covers on the cups. For these reasons, there is a relatively large art, for example D 426,431; U.S. Pat. Nos. 4,979,657; 5,704,671; and 5,743,389; addressing the problems of transporting soft drinks and coffee at sporting venues and such.
The present invention is an adaptable arm tote or carrier which is inexpensive to manufacture and simple to use.

Adaptable tote for beverage cups and plates


A line transceiver apparatus for multiple transmission standards including a operational amplifier (OP-AMP), a transformer unit, a first variable resistor unit to a sixth variable resistor unit, and a variable resistor control unit is provided. The first resistor and the second resistor are coupled between transmission nodes of the line transceiver apparatus and input nodes of the OP-AMP, and the load nodes of the transformer unit are receiving nodes of the line transceiver apparatus. The variable resistor control unit adjusts the impedances of the first variable resistor unit to the sixth variable resistor unit according to a transmission standard selection signal so as to enable the line transceiver apparatus to support multiple transmission standards.

1. Field of the Invention
The disclosure is related to a line transceiver apparatus, and in particular to a line transceiver apparatus which supports multiple transmission standards.
2. Description of Related Art
Ethernet is currently the most commonly used local area network technology, and the technical standards thereof, such as the technologies related to connections between physical layers and interactions between devices and physical media in open system interconnection (OSI) reference models, have been established in the IEEE 802.3 standard by the Institute of Electrical and Electronics Engineers (IEEE). Currently, twisted pair lines are often used in Ethernet as transmission lines for a communication network, so that electromagnetic interference and crosstalk are reduced.
Since technology related to Ethernet are constantly evolving, many different transmission standards are developed. Currently, some main standards that are widely used include the 10BASE-T standard, the 100BASE-T standard (which is also termed the "Fast Ethernet" standard), and the 1000BASE-T standard (which is also termed the "Gigabit Ethernet" standard). The baseband transmission speed of the above standards are respectively 10 megabits per second (Mbit/s), 100 Mbit/s, and 1000 Mbit/s. There are also other transmission standards for special uses, such as the 10BASE-TE standard which consumes less electricity during data transmission compared to the 10BASE-T standard. "BASE" is the abbreviation for "baseband." "T" stands for the use of twisted pair lines as transmission lines. The most commonly used twisted pair lines for Ethernet nowadays is the Category 5 line, abbreviated the CAT-5 line. In the above Ethernet baseband transmission standards, the same connector is used, that is, the RJ-45 connector, and standards with higher speeds are mostly compatible with the standards with lower speeds, so that under most circumstances, network equipment adopting different standards with different speeds may be used together.
In Ethernet wired communication technology, line transceivers are used by network equipment such as network interface cards to transmit and receive signals on transmission lines. Since network interface cards are expected to be compatible with Ethernet transmission standards, such as the 10/100/1000BASE-T standards, network interface cards require line transceiver apparatuses which support multiple transmission standards. FIG. 1 is a schematic circuit structure of a conventional line transceiver apparatus 10 which supports multiple transmission standards. Please refer to FIG. 1, a transmission node (such as a network interface card or another piece of network equipment which is not shown) provides a signal Vin to input nodes NVin+ and NVin− of the line transceiver apparatus, and uses the line transceiver apparatus 10 to generate a load signal VL, so as to transmit a signal through a transmission line (here the transmission line is viewed as an external load 130), or the transmission node uses the line transceiver apparatus 10 to receive the load signal VL carried by the transmission line.
The line transceiver apparatus 10 has an operational amplifier (OP-AMP) 110, resistors, 101-104, resistors 111 and 112, and a transformer unit 120 which is able to adjust a turns ratio. The resistors 101-104 are capable of controlling a transmission gain of the OP-AMP 110, wherein the resistors 101 and 102 have an impedance of R1, and the resistors 103 and 104 have an impedance of R2. Therefore, an equation (1) for calculating a transmission gain GainTX is shown below:GainTX=R2/R1  (1)
In the 10BASE-T standard, a voltage amplitude of the load signal VL is about ±2.5 V, whereas in other standards, such as in the 100BASE-T standard and in the 1000BASE-T standard, the load signal VL which supports these standards clearly has a lower voltage amplitude. For example, the voltage amplitude of the load signal VL in the 100BASE-T/1000BASE-T standard is about ±1 V, and the voltage amplitude of the load signal VL in the 10BASE-TE standard is about ±1.5 V to ±1.9 V. Therefore, when the line transceiver apparatus 10 determines the transmission gain GainTX according to the selected transmission standard (such as the 100BASE-T standard), the ratio of the impedance R1 to the impedance R2 is also determined, so that the line transceiver apparatus 10 is unable to transmit or receive the load signal VL under the 10BASE-T standard, and the line transceiver apparatus 10 is hence also unable to fulfill a requirement of supporting multiple transmission standards.
Therefore, in order to support other transmission standards, the line transceiver apparatus 10 uses the transformer unit 120 which is capable of adjusting a turns ratio (such as the transformer unit which has a turns ratio of 1:M, wherein M≧2.) and uses the resistors 111 and 112 to adjust the transmission gain, so that the line transceiver apparatus 10 is able to transmit and receive the load signal VL carried by the transmission line under different transmission standards. However, the transformer unit 120 which has a turns ratio of 1:M is more expensive than transformer units which have a turns ratio of 1:1, and impedance matching can hardly be achieved between an output impedance RTR of the line transceiver apparatus 10 (which the impedance of the of the line transceiver apparatus 10 from an external impedance RL) and the external load RL. Hence it is difficult to achieve the minimum reflective noise and the maximum power transfer efficiency in different transmission standards.

Line transceiver apparatus for multiple transmission standards


An acoustic wave device includes: a substrate; a lower electrode formed on the substrate; at least two piezoelectric films formed on the lower electrode; an insulating film located between the at least two piezoelectric films; and an upper electrode formed on the at least two piezoelectric films, wherein an outer periphery of an uppermost piezoelectric film out of the at least two piezoelectric films in a region in which the lower electrode and the upper electrode face each other is positioned further in than an outer periphery of the upper electrode.

An acoustic wave device using a piezoelectric thin film resonator has been used as a filter for wireless devices and the like for example. A piezoelectric thin film resonator has a structure in which a lower electrode and an upper electrode face each other across a piezoelectric film. Filters and duplexers are examples of the acoustic wave device using a piezoelectric thin film resonator. In these acoustic wave devices, the resonance frequency, anti-resonance frequency, passband and the like change in accordance with a temperature. A technique in which an insulating film is provided in the piezoelectric film is known as a technique that compensates for these changes in accordance with a temperature as disclosed in Japanese Patent Application Publication No. 58-137317 and Proc. IEEE Ultrasonics Symposium 2009, pp 859-862 for example.
However, in the above technique, resonance characteristics of the acoustic wave device such as a Q-value and an electromechanical coupling coefficient are not sufficient.


A process, apparatus, and system for generating and using lookup tables to convert image signals from a multi-component format to a single-index CLUT format for an arbitrary CLUT palette. In a preferred embodiment, lookup tables are generated for an arbitrary CLUT palette and used to convert (with Y, U, and V dithering) three-component subsampled YUV9 video signals to 8-bit CLUT signals.

1. Field of the Invention
The present invention relates to digital image signal processing, and, in particular, to computer-implemented processes, apparatuses, and systems for color converting digital image signals.
2. Description of the Related Art
Conventional systems for displaying video images in a PC environment are limited, in part, by the processing capabilities of the PC processors. These limitations include low video frame rates and small video window sizes for display of video images. Such limitations result in low video quality. As a result, some conventional systems for playing video in a PC environment require additional hardware that is designed to process video signals at the rates needed to provide acceptable video quality.
It is desirable to provide a video decoding system for displaying high-quality, full-motion digital video images on a graphics display monitor in a personal computer (PC) environment that does not require any additional hardware. Such a decoding system is preferably capable of performing decoding, conversion, and display functions to support a video playback mode. In playback mode, the decoding system accesses encoded video signals from a mass storage device, decodes the signals into a multi-component (e.g., subsampled three-component YUV9) video format, converts the multi-component signals to single-index color lookup table (CLUT) signals, and uses the CLUT signals to generate displays for a display monitor.
It is also desirable to provide a video encoding system for generating the encoded video signals that will be decoded and displayed by the video decoding system. Such an encoding system is preferably capable of performing capture, encoding, decoding, conversion, and display functions to support both a compression mode and the playback mode. In compression mode, the encoding system captures and encodes video images generated by a video generator, such as a video camera, VCR, or laser disc player. The encoded video signals may then be stored to a mass storage device, such as a hard drive or, ultimately, a CD-ROM. At the same time, the encoded video signals may also be decoded, converted, and displayed on a display monitor to monitor the compression-mode processing.
Conventional means for converting three-component video signals to single-index CLUT signals in video processing (i.e., encoding or decoding or both) systems typically define some or all of the palette colors of the finite CLUT that is used to display the video images. There are, however, computer application programs (for use in PC-based video processing systems) that also define the CLUT palette. What is needed is color conversion means for converting three-component video signals to single-index CLUT signals in a video processing system, where the color conversion means uses an arbitrary pre-defined CLUT palette, such as the CLUT palette defined by a computer application program running on the video processing system.
It is accordingly an object of this invention to overcome the disadvantages and drawbacks of the conventional art and to provide a video decoding system for displaying high-quality, full-motion video images in a PC environment.
It is a further object of this invention to provide a video encoding system for generating the encoded video signals to be decoded, converted, and displayed by the video decoding system.
It is a particular object of the present invention to provide efficient color conversion of three-component image signals to single-index CLUT signals for use in generating displays on a display monitor.
It is a further particular object of the present invention to provide means for converting three-component video signals to single-index CLUT signals using an arbitrary pre-defined CLUT palette.
Further objects and advantages of this invention will become apparent from the detailed description of a preferred embodiment which follows.

Process, apparatus, and system for color conversion of image signals


A marketing indicator assembly is comprised of an integral elongate sheet member of synthetic plastic material having first and second longitudinally spaced ends, a marketing indicator secured to the sheet member and extending therewith from the sheet member second end to a preselected location spaced from the sheet member second end, an end portion of the marketing indicator at the preselected location being not secured to the sheet member and bearing an adhesive layer, and a removable member secured to the adhesive layer and in facing relation to the sheet member.

For purposes of indicating marketing parameters, e.g., article manufacturer, price, size and the like, longstanding conventional practice involves the use of a so-called "swift tacks" involving a plastic filament which is passed through an opening in a paper or cardboard UPC (universal product code) tag or ticket and then secured at filament ends to remain with the article until the filament is cut apart at checkout.
The swift tacks with plastic filament have tendencies, where articles are hung adjacently, to snag with adjacent swift tacks, undermining the display effort. Also, where the swift tacks are applied at the point of article manufacture, they tend undesirably, to become entangled with one another in the course of packaging, shipping and unpacking. Further, swift tacks can damage the articles to which they are attached and are aesthetically unappealing from a display point of view.
In commonly-assigned U.S. Pat. No. 5,334,274, applicants herein provide a method for use in belt making wherein a marketing indicator is secured with the belt at the time of the assembly of the belt blank and the belt buckle.
More particularly, in making belts having buckles of the type having a prong pivotally supported by an arm of the buckle frame, following the step of applying a belt-retaining loop member to the belt blank and buckle disposed therewith, a portion of a marketing indicator is applied to the undersurface of the belt blank, interiorly of the boundary of the subsequent stitching, thereby to be secured with the stitched assembly.
When the stitching is performed, as is customary, in an inverted disposition of the belt blank, the '274 patent practice looks to retentive application of the marketing indicator to the undersurface of the belt blank. To this end, the portion of the indicator which is disposed interiorly of the stitching, or at least a part of such portion, has an adhesive backing applied thereto for securement thereof to the belt blank. Accordingly, upon inversion of the belt blank, the indicator remains with the belt blank, without assembler assistance.
To the extent, as is discussed in detail hereinafter, that applicants' subject invention involves the display of marketing information by folding a plastic sheet member to define a loop circumscribing a member on an article, attention is also invited to the folding tail belt hanger depicted in U.S. Pat. No. 3,710,996, which discloses a hanger for the hanging of belts having buckles with prongs, wherein a plastic sheet member is folded into a loop which circumscribes a portion of the buckle frame. Marketing information, such as manufacturer's logo, size, etc., is displayed on the plastic sheet member. The loop is secured by intermating of a projection and an opening of the sheet member.

Marketing indicator assembly and article combined therewith


A method for adhering a medical device to biological tissue includes adhering an adhesive composition having a plurality of reactive members of a specific binding pair to tissue which has a plurality of complementary reactive members of the specific binding pair via click chemistry.

1. Technical Field
The present disclosure relates to adhesive modalities for repair of biological tissues.
2. Related Art
Medical adhesives or "tissue glue" have much potential in medicine. Certain adhesive materials are known which may be used to adhere tissue such as skin. For example, cyanoacrylate adhesives been used to bond tissue. In addition to cyanoacrylate adhesives, other types of materials have been reported to adhere to skin. For example, U.S. Pat. No. 4,839,345 to Doi et al. reports a hydrated crosslinked protein adhesive gel that is used as a cataplasm or cosmetic mask that will externally adhere to skin but can be removed and then re-adhered to the skin. Other crosslinked protein hydrogels have been reported to serve as a proteinaceous substrate to deliver therapeutic agents such as enzymes or drugs through skin or mucous membranes. Still other materials have been used as hemostatic agents to stop or prevent bleeding. For example, mixtures of fibrinogen and thrombin such as TISSEEL® sealant available from Baxter International, Inc. or BERIPLAST-P® hemostatic agent or sealant available from Aventis Behring, have been used in vascular surgery to seal tissue such as blood vessels and thus prevent blood leakage.
The use of medical gels such as hydrogels can be advantageous due to the physico-chemical properties of the hydrogels. Hydrogels typically have excellent compatibility with human and animal tissue. Physically cross linked hydrogels can withstand attack by body fluids, blood, urine and other bodily secretions without significant damage. Many are typically non-adherent to tissue, do not have an affinity for binding to proteins and do not have cell adsorption. Hydrogels are typically non-thrombogenic. These characteristics have been utilized, e.g., for prevention of adhesions after surgery. The ability of hydrogels to act as bulking agents has been utilized in connection with treatment of gastroesophageal reflux disease (GERD), urinary incontinence, fecal incontinence and sterilization of mammals. Hydrogels have also been used to create a matrix in the treatment of damaged cartilage.
Click chemistry is a popular term for reliable reactions that make it possible for certain chemical building blocks to "click" together and form an irreversible linkage. See, e.g., US Pub. No. 2005/0222427. In the case of azide-alkyne click chemistry, the reactions may be catalyzed or uncatalyzed. For example, copper-free click chemistry was recently developed by Bertozzi and colleagues using difluorinated cyclooctyne or DIFO that reacts with azides rapidly at physiological temperatures without the need for a toxic catalyst. See, e.g., Baskin et al., Copper Free Click Chemistry for Dynamic In Vivo Imaging, PNAS, vol. 104, no. 43, 16793-16797 (Oct. 23, 2007). The critical reagent, a substituted cyclooctyne, possesses ring strain and electron-withdrawing fluorine substituents that together promote a [3+2] dipolar cycloaddition with azides. See also, US Pub. No. 2006/0110782 and Codelli et al., Second Generation Difluorinated Cyclooctynes for Copper-Free Click Chemistry, J. Am. Chem. Soc., vol. 130, no. 34, 11486-11493 (2008). Another suitable cyclooctyne is 6,7-dimethoxyazacyclooct-4-yne (DIMAC). See, Sletton and Bertozzi, A hydrophilic azacyclooctyne for Cu-free click chemistry, Org. Lett. (2008) 10 (14), 3097-3099. Other click chemistry reactions include Diels-Alder reactions, thiol-alkene reactions, and maleimide-thiol reactions.
It would be advantageous to be able to secure a bifunctional adhesive layer having one functionality which provides selective attachment to a target site within the body and another functionality which provides an adhesive surface for selective attachment of a medical device to the adhesive layer at the target site.

Functionalized adhesive for medical devices