An expansion key generating device that receives encryption key data as input, and outputs plural expansion key data, comprising: a data dividing unit operable to divide the encryption key data into plural part key data; and plural key conversion units being connected in series, which output the plural expansion key data. Each of the plural key conversion units includes: an output calculation unit operable to receive the plural part key data or plural output data from a preceding key conversion unit as plural input data, which executes a fixed conversion process for each of the plural input data in so that each bit value of each of the plural input data does not interfere each other, and further outputs plural output data to a subsequent key conversion unit; and an expansion key calculation unit operable to combine plural input data and calculate the expansion key data.

(1) Field of the Invention
The present invention relates to an encryption system. More specifically, the present invention relates to an encryption system which has a decreased difference between encryption time and decryption time, and is capable of generating a highly random expansion key.
(2) Description of the Related Art
Due to a rapid spread of digital communication in recent years, a data encryption method for securing data confidentiality through communication is highly demanded for the purpose of protecting privacy and the development of sound industries. In order to realize an encryption method, a speedy encryption process, and easy implementation, and a high security level are required. In a generic structure of such an encryption method, the data subject for encryption is divided into blocks of a specific size, a data scrambling process is executed to each block based on a specific encryption key, and then a ciphertext is generated.
(First Related Art)
As one of such encryption methods, there is Rijndael encryption which is established as the Advanced Encryption Standard (AES). The AES is the next generation standard of encryption in the United States. FIG. 16 is a diagram showing the internal structure of an encryption device using the Rijndael encryption method. The encryption device 1300 includes an expansion key generating unit 6 that generates and outputs 128-bit expansion keys SK0˜SK10 from a 128-bit encryption key EK, and a data scrambling unit 5 that is connected to the expansion key generating unit 6. The data scrambling unit 5 receives the expansion keys SK0˜SK10 from the expansion key generating unit 6, executes a data scramble by repeating a specific data conversion process for a plain text PT of 128-bit data using the expansion keys SK0˜SK10, and generates a 128-bit ciphertext CT.
The expansion key generating unit 6 includes the following elements: a data dividing unit 600 that receives the encryption key EK, divides the encryption key EK into four 32-bit data blocks D0, D1, D2 and D3, and outputs them; a key conversion unit 60 that is connected to the data dividing unit 600, receives the data blocks D0˜D3 from the data dividing unit 600, executes a specific operation, which is explained later, to them, and generates the expansion key SK1 and four 32-bit data blocks, and outputs them; and key conversion units 61˜69, each of which is connected to the preceding key conversion unit, receives four 32 bits data blocks from the key conversion unit, executes a specific operation, which is explained later, to them, generates the expansion key and four 32-bit data blocks, and outputs them.
The expansion keys output from the key conversion units 61˜69 are defined as the expansion keys SK2˜SK10 respectively. Although the key conversion unit 69 outputs four data blocks, they are not used for other processes. In addition, the expansion key generating unit 6 outputs the encryption key EK as the expansion key SK0.
The data scrambling unit 5 includes the following elements: a key adding unit 500, which is connected to the expansion key generating unit 6, where the key adding unit 500 receives the expansion key SK0, executes an exclusive-OR operation per bit between a plain text PT and the expansion key SK0, a data conversion unit 50 connected to the key adding unit 500 and the key conversion unit 60 which converts the data output from the key adding unit 500 based on the expansion key SK1; data conversion units 51˜58 which are connected to the key conversion units 61˜68 respectively, and convert the data output from the preceding data conversion unit based on the expansion keys SK2˜SK9 respectively; and a final data conversion unit 59, which is connected to the data conversion unit 58 and the key conversion unit 69, where the final data conversion unit 59 converts the data output from the data conversion unit 58 based on the expansion key SK10, and outputs a ciphertext CT.
FIG. 17 is a diagram showing the internal structure of the key conversion units 60˜69. Each of the key conversion units 60˜69 executes a key conversion process, which is explained later, based on first˜fourth input data X0˜X3 of 32 bits each, and outputs first˜fourth output data Y0˜Y3 and the 128-bit expansion key SK.
Each of the key conversion units 60˜69 includes the following elements: a data rotation unit 601 that receives the fourth input data X3, executes a rotation bit shift by 8 bits to the input data X3 in an upper bit direction (a left direction), and outputs its result; a data substituting unit 602 that is connected to the data rotation unit 601, receives the operation result from the data rotation unit 601, executes a specific substituting process to the operation result, and outputs its result; and an exclusive-OR operation unit 603, which is connected to the data substituting unit 602, where the exclusive-OR operation unit 603 receives the substitution result from the data substituting unit 602, executes the exclusive-OR operation per bit between the substitution result and a predefined 32-bit constant Rcon, and outputs data T.
Each of the key conversion units 60˜69 further includes the following elements: an exclusive-OR operation unit 604 that is connected to the exclusive-OR operation 603, where the exclusive-OR operation unit 604 receives the first input data X0 and the data T output from the exclusive-OR operation unit 603, executes the exclusive-OR operation per bit between the first input data X0 and the data T, and outputs the first output data Y0; and an exclusive-OR operation unit 605 which is connected to the exclusive-OR operation unit 604, where the exclusive-OR operation unit 605 receives the second input data X1 and the operation result of the exclusive-OR operation unit 604, executes the exclusive-OR operation per bit between the second input data X1 and the operation result, and outputs the second output data Y1.
Each of the key conversion units 60˜69 further includes: an exclusive-OR operation unit 606 which is connected to the exclusive-OR operation unit 605, where the exclusive-OR operation unit 606 receives the third input data X2 and the operation result of the exclusive-OR operation unit 605, executes the exclusive-OR operation per bit between the third input data X2 and the operation result, and outputs the third output data Y2; an exclusive-OR operation unit 607 which is connected to the exclusive-OR operation unit 606, where the exclusive-OR operation unit 607 receives the fourth input data X3 and the operation result of the exclusive-OR operation unit 606, executes the exclusive-OR operation per bit between the fourth input data X3 and the operation result, and outputs the fourth output data Y3; and a data concatenation unit 608 which is connected to the exclusive-OR operation units 604˜607, where the data concatenation unit 608 concatenates the first˜fourth output data Y0˜Y3, and outputs the expansion key SK. Details of the process executed in each unit are described in the following explanations of the encryption process.
The following briefly describes the encryption process of the Rijndael encryption method executed by the encryption device 1300. As indicated in FIG. 16, the expansion key generating unit 6 outputs the encryption key EK as the expansion key SK0 to the key adding unit 500 within the data scrambling unit 5. The key adding unit 500 executes the exclusive-OR operation per bit between the plain text PT and the expansion key SK0 and outputs its result to the data conversion unit 50. The data dividing unit 600 divides the encryption key EK by each 32 bits from its upper bit into four data blocks D0, D1, D2 and D3.
Data entered into the data conversion unit 50 is sequentially processed for data conversion in each data conversion unit in the order from the data conversion unit 50 to the data conversion unit 58, and a result finally processed in the final data conversion unit 59 is output as the ciphertext CT.
Each of the data conversion units 50˜58 executes the data conversion process based on the expansion keys SK1˜SK9. Also, the final data conversion unit 59 executes the data conversion process based on the expansion key SK10. Each of the expansion keys SK1˜SK10 is generated in each of the key conversion units 60˜69 within the expansion key generating unit 6, and respectively provided to the data conversion units 50˜58 and the final data conversion unit 59 in the data scrambling unit 5. That is to say, there is a processing group at each stage, which consists of following processes (1) and (2) as a pair, and the data scrambling unit 5 executes 10 stages of them and generates the ciphertext CT.
Each of the key conversion units 60˜69 receives the first˜fourth input data X0˜X3 (32 bits each), executes the key conversion process, and outputs the expansion key SK (128 bits) and the first˜fourth output data Y0˜Y3. The data rotation unit 601, the data substituting unit 602 and the exclusive-OR operation unit 603 calculate the data T by conducting the operation expressed as the following formula (1) to the fourth input data X3.T=Rcon(+)Perm(ROTL8(X3))  (1)Here, ROTL8 (X) indicates a result of the rotation bit shift by 8 bits executed to the data X in the upper bit direction (the left direction). Perm (X) indicates a result of a specific substituting process executed to the data X. An operator "(+)" indicates the exclusive-OR operation per bit. The constant Rcon is 32-bit fixed value data which is different in each key conversion units 60˜69.
Each of the exclusive-OR operation units 604˜607 executes the operation indicated in the following formulas (2)˜(5) using the data T resulted from above, and finds the respective first˜fourth output data Y0˜Y3.Y0=T(+)X0  (2)Y1=Y0(+)X1  (3)Y2=Y1(+)X2  (4)Y3=Y2(+)X3  (5)
The data concatenation unit 608 gets the expansion key SK containing a relation expressed in the following formula (6). The operator "∥" indicates data concatenation. That is to say, the below formula (6) shows the 128-bit expansion key SK can be found by concatenating the first˜fourth output data Y0˜Y3 having 32 bits each.SK=Y0∥Y1∥Y2∥Y3  (6)
Each of the key conversion units 60˜69 outputs the expansion key SK and the first˜fourth output data Y0˜Y3 obtained as a result of the above process.
FIG. 18 is a diagram to show the internal structure of the decryption device using the Rijndael encryption method. A decryption device 1400 includes the following elements: an expansion key inverse generating unit 8 that generates the expansion keys SK10˜SK0 of 128 bits each in a reverse order of encryption, which is from the 128-bit encryption key EK; and a data inverse scrambling unit 7 that is connected to the expansion key inverse generating unit 8, receives the expansion keys SK10˜SK0 from the expansion key inverse generating unit 8, executes a specific inverse data scrambling process to the 128-bit ciphertext using the expansion keys SK10˜SK0, and outputs the decryption text DT.
The expansion key inverse generating unit 8 includes the following elements: a data dividing unit 800 which receives the encryption key EK and divides it by each 32 bits from its upper level into four data blocks; a key conversion unit 80 which is connected to the data dividing unit 800, where the key conversion unit 80 receives the four blocks, executes a specific operation to them and outputs four 32-bit data blocks; key conversion units 81˜88, each of which is connected to the preceding key conversion unit, where each key conversion unit 81˜88 receives four 32-bit data blocks from the preceding key conversion unit, executes a specific operation to them, generates and outputs four 32-bit data blocks to the next key conversion unit; and a key conversion unit 89 which is connected to the key conversion unit 88, where the key conversion unit 89 receives four 32-bit data blocks from the key conversion unit 88, executes a specific operation to the four 32-bit data blocks, and generates and outputs the expansion key SK10 and four 32-bit data blocks.
Since the specific operation executed by the key conversion units 80˜89 is the same as the specific operation executed by the key conversion units 60˜69 respectively, each of the key conversion units 80˜89 has the same structure as the key conversion unit indicated in FIG. 17. Therefore, they are not explained here in detail.
However, the key conversion units 80˜88 do not output the expansion keys SK1˜SK9, which are different from the key conversion units 60˜68. Because of this, each of the key conversion units 80˜88 may have the structure of the key conversion unit shown in FIG. 17 where the data concatenation unit 608 is excluded.
The expansion key inverse generating unit 8 further includes the following elements: a key inverse conversion unit 90 which is connected to the key conversion unit 89, where the key conversion unit 90 receives four 32-bit data blocks output from the key conversion unit 89, executes a key inverse conversion process, which is explained later, generates and outputs the expansion key SK9 and four 32-bit data blocks, and key inverse conversion units 91˜99, each of which is connected to the key inverse conversion unit, where each of the inverse conversion units 91˜99 receives four 32-bit data blocks from the preceding key inverse conversion unit, executes the key inverse conversion process, which is explained later, generates and outputs the expansion key and four 32-bit data blocks.
Each of the expansion keys output from the key inverse conversion units 90˜99 are the respective expansion keys SK9˜SK0. The key inverse conversion unit 99 outputs four data blocks, but they are not used for other processes.
The data inverse scrambling unit 7 includes the following elements: a final data inverse conversion unit 70 which is connected to the key conversion unit 89, where the final data inverse conversion unit 70 receives the expansion key SK10 from the key conversion unit 89, executes an inverse conversion process of the conversion process executed by the final data conversion unit 59 using the ciphertext CT and the expansion key SK10, and outputs the process result; and a data inverse conversion unit 71 which is connected to the final data inverse conversion unit 70 and the key inverse conversion unit 90, where the data inverse conversion unit 71 respectively receives the process result and the expansion key SK9 from the final data inverse conversion unit 70 and the key inverse conversion unit 90, executes the inverse conversion process of the conversion process executed by the data conversion unit 58, and outputs the process result.
The data inverse scrambling unit 7 further includes the following elements: data inverse conversion units 72˜79, each of which is connected to the preceding data inverse conversion unit respectively and also connected the key inverse conversion units 91˜98 respectively, where each of the date inverse conversion units 72˜79 receives the expansion keys SK8˜SK1 respectively from the key inverse conversion units 91˜98, executes respectively the inverse conversion process of the conversion process executed by the data conversion units 57˜50, and outputs the process result; and a key adding unit 700 which is connected to the data inverse conversion unit 79 and the key inverse conversion unit 99, where the key adding unit 700 receives the process result and the expansion key SK0 respectively from the data inverse conversion unit 79 and the key inverse conversion unit 99, executes the inverse conversion process of the conversion process executed in the key adding unit 500, and outputs the decryption text DT.
FIG. 19 is a diagram to show each internal structure of the key inverse conversion units 90˜99. Each of the key inverse conversion units 90˜99 executes the key inverse conversion process, which is equivalent to the inverse conversion of the key conversion process executed respectively in each of the key conversion units 60˜69 and 80˜89 based on the first˜fourth input data Y0˜Y3, which is 32 bits each, and outputs the first˜fourth output data Z0˜Z3 and the 128-bit expansion key SK.
Each of the key inverse conversion units 90˜99 includes following units: an exclusive-OR operation unit 901 that executes the exclusive-OR operation per bit between the third input data Y2 and the fourth input data Y3, and outputs the fourth output data Z3; an exclusive-OR operation unit 902 that executes the exclusive-OR operation per bit between the second input data Y1 and the third input data Y2, and outputs the third output data Z2; and an exclusive-OR operation unit 903 that executes the exclusive-OR operation per bit between the first input data Y0 and the second input data Y1, and outputs the second output data Z1.
Each of the key inverse conversion units 90˜99 further includes the following elements: a data rotation unit 905 which is connected to the exclusive-OR operation unit 901, receives an output of the exclusive-OR operation unit 901, where each of the key inverse conversion units 90˜94 executes the rotation bit shift by 8 bits to the output in the upper bit direction (the left direction), and outputs the result; and a data substituting unit 906 which is connected to the data rotation unit 905, where the data rotation unit 905 receives the operation result from the data rotation unit 905, executes a specific substituting process to the operation result, and outputs the result.
Each of the key inverse conversion units 90˜99 further includes the following elements: an exclusive-OR operation unit 907 that is connected to the data substituting unit 906, where the exclusive-OR operation unit 907 receives the substituting result from the data substituting unit 906, executes the exclusive-OR operation per bit between the substituting result and a 32-bit constant Rcon predefined in each of the key inverse conversion units 90˜99, and outputs data T; an exclusive-OR operation unit 904 which is connected to the exclusive-OR operation unit 907, where the exclusive-OR operation unit 904 receives the data T from the exclusive-OR operation unit 907, executes the exclusive-OR operation per bit between the first input data Y0 and the data T, and outputs the first output data Z0; and a data concatenation unit 908 which is connected to the exclusive-OR operation units 904˜901, where the data concatenation unit 909 concatenates the first˜fourth output data Z0˜Z3, and outputs the expansion key SK. Details of the process taken in each unit are described in the following explanation of a decryption process.
The following briefly describes the decryption process of the Rijndael encryption method executed by the decryption device 1400. As shown in FIG. 18, the data dividing unit 800 divides the 128-bit encryption key EK by each 32 bits from its upper bit into four 32-bit data blocks. A key conversion process is sequentially executed based on these four data blocks in the key conversion units 80˜89. As mentioned above, the key conversion process executed in the key conversion units 80˜89 is the same as the key conversion process done in the key conversion units 60˜69 indicated in FIG. 16. However, the expansion keys SK1˜SK9 respectively generated in the key conversion units 80˜88 are not used for any subsequent processes.
A key conversion unit 89 outputs the generated expansion key SK to the final data inverse conversion unit 70 as the expansion key SK10. Subsequently, each of the key inverse conversion units 90˜99 generates the respective expansion keys SK9˜SK0 in order. In parallel with the processes executed in the key conversion unit 89 and the key inverse conversion units 90˜99, the final data inverse conversion unit 70, the data inverse conversion units 71˜79 and key adding unit 700 execute a specific process respectively based on the expansion keys SK10˜SK0. The key adding unit 700 finally generates the decryption text DT, and outputs it.
Next, the following describes details of a process executed in the data inverse scrambling unit 7. The process done in the data inverse scrambling unit 7 is equivalent to inverse conversion of the process taken place in the data scrambling unit 5 of the encryption device 1300 indicated in FIG. 16. Initially, the final data inverse conversion unit 70 executes the inverse conversion process of the process carried out by the final data conversion unit 59 with the expansion key SK10. Subsequently, the data inverse conversion units 71˜79 respectively conduct the inverse conversion process of the process in the data conversion units 58˜50 using the respective expansion keys SK9˜SK1. Lastly, the key adding unit 700 executes the inverse conversion process of the process executed in the key adding unit 500 using the expansion key SK0 and generates the decryption text DT, and outputs it. As mentioned above, at the time of decryption, it is necessary to generate the expansion key in a reverse order of the encryption processes.
The following describes the key inverse conversion process executed in each of the key inverse conversion units 90˜99 indicated in FIG. 19.
Each of the exclusive-OR operation units 901˜903 finds the respective second˜fourth output data Z1˜Z3 by executing each operation shown in the following formulas (7)˜(9).Z1=Y0(+)Y1  (7)Z2=Y1(+)Y2  (8)Z3=Y2(+)Y3  (9)
The data rotation unit 905, the data substituting unit 906 and the exclusive-OR operation unit 907 calculate the data T by executing the operation indicated in the following formula (10) for the fourth output data Z3.T=Rcon(+)Perm(ROTL8(Z3))  (10)
The exclusive-OR operation unit 904 finds the first output data Z0, which is the exclusive-OR operation per bit between the data T and the first input data Y0 according to the next formula (11).Z0=T(+)Y0  (11)
The data concatenation unit 908 concatenates the first˜fourth output data Z0˜Z3 according to the next formula (12), and generates the 128-bit expansion key SK.SK=Z0∥Z1∥Z2∥Z3  (12)
Each of the key inverse conversion units 90˜99 outputs the expansion key SK resulted from the above process and the first˜fourth output data Z0˜Z3.
As shown in FIG. 17, the data substituting unit 602 executes a non-linear process at the time of encryption according to this method. There is an impact on the expansion key SK and all of the output data from the data processed by the non-linear process via the exclusive-OR operation units 604˜607. Therefore, though this method is a simple key conversion process, it can generate a highly random expansion key.
(Second Related Art)
The U.S. standard known as the Data Encryption Standard (DES) is the second related art. FIG. 20 is a diagram showing the structure of the key conversion unit 10 used by an encryption device in the DES method. A key conversion unit 10 includes rotation shift units 101 and 102, a data concatenation unit 103 which is connected to the rotation shift units 101 and 102, and a data degenerating unit 104 which is connected to the data concatenation unit 103.
The following describes actions of the key conversion unit 10. The rotation shift unit 101 executes a rotation bit shift process by a specific number of bits to 28-bit first input data, and generates first rotation shift data. The rotation shift unit 102 executes the rotation bit shift process by a specific number of bits to 28-bit second input data, and generates second rotation shift data. The first rotation shift data and the second rotation shift data are output as first output data and second output data respectively from the key conversion unit 10. On the other hand, the data concatenation unit 103 concatenates the first rotation shift data and the second rotation shift data to make 56-bit data, and outputs the data to the data degenerating unit 104. The data degenerating unit 104 extracts data for 48 bits at a predefined bit location from the input data, and outputs the expansion key.
According to the encryption device in the DES method the same expansion key generation process can be applied to generate the expansion key both at the encryption process and at the decryption process because generating the expansion key is basically realized by a data shift process and a data extraction process. Accordingly, there is no difference between the encryption and the decryption processes regarding the processing workload necessary for generating the expansion key.
The above mentioned inventions as well as other related inventions contain deficiencies. In regards to the encryption method of the first related art, the time required to execute the generating process for the expansion key at the decryption stage is greater than the time required at the encryption stage. These timing differences occur for the following reasons. As shown in FIG. 16, in the data scrambling unit 5 of the encryption device 1300, the encryption key EK is used as is in the key adding unit 500 that executes the first process. Therefore, a process of the data scrambling unit 5 can be executed in parallel with a process of the expansion key generating unit 6.
On the other hand, as indicated in FIG. 18, within the data inverse scrambling unit 7 of the decryption device 1400, the final data inverse conversion unit 70, which executes the process at first, must use the expansion key SK10 provided from the expansion key inverse generating unit 8. In order to get the expansion key SK10, a key conversion process needs to be carried out in the key conversion units 80˜89. That is to say, the final data inverse conversion unit 70 can start its process only after the key conversion process is executed 10 times. Therefore, the decryption process takes more time than the time taken for the encryption process because these key conversion processes must take place.
When the above-described time gap is significantly large, the following problems arise. Consider, for example, a communication system where data is exchanged in a real time manner between a receiving device and a sending device. If the encryption device 1300 and the decryption device 1400 explained in the first related art are used in such a communication system, the sending device can encrypt data and send it in a real time manner. However, the receiving device cannot decrypt the encryption message in a real time manner because the decryption takes time. Accordingly, the prior art requires the use of a margin at the receiving device to temporarily store the encrypted data, which increases the cost of the receiving device.
Also, as shown in FIG. 21, where an Electronic Toll Collection (ETC) system 1800 installed to a tollgate of expressways, data communication takes place between a tollgate antenna 1804 and an in-vehicle device 1802 which is attached to an automobile 1801 and authentication is executed between the tollgate antenna 1804 and the in-vehicle device 1802. Because the automobile 1801 normally travels through the gate of the ETC system 1800 without stopping, a high-speed response is required for the ETC system 1800. Therefore, if the conventional encryption device 1300 and decryption device 1400 are used in the ETC system 1800, high-speed hardware will be required.
On the other hand, the problem of the first related art, being "the time required to generate the expansion key at the decryption takes longer than the time at the encryption", is resolved in the second related art. However, the second related art still contains a problem where the expansion key is not sufficiently at random.
In the second related art, data is treated as an expansion key wherein a certain number of bits at a specific position are extracted from the concatenated data after a rotation bit shift is applied. Since a data combining process or a substituting process is not used for a process to generate the expansion key, the expansion key is not adequately random. Regarding the generation process of the expansion key in the second related art, the key cannot maintain a high security level. This is typically called a "weak key". The weak key in the DES method is described, for example, in "Alfred J. Menezes, Paul C. van Oorschot, Scott A. Vanstone, "Handbook of Applied Cryptography", CRC Press, 1997, pp. 256–pp. 259".

Expansion key generating device, encryption device and encryption system

Matsushita Electric Industrial Co., Ltd.


An accessory tool for a vacuum cleaner comprises an elongated body having a plurality of furrows for imparting flexibility to the accessory tool. The elongated body is further be made of a material that is selected to impart flexibility to the accessory tool so that the longitudinal axis of the elongated portion can be bent about a radius through an angle up to 45° without kinking or breaking in a direction transverse to and laterally of elongated cross-sectional configuration.

1. Field of the Invention
This invention relates to above-the-floor cleaning attachments for vacuum cleaners. In one of its aspects, the invention relates to a cleaning tool that is adaptable for different types small constricted areas.
2. Description of the Related Art
In addition to having floor suction nozzles for on-the-floor cleaning, vacuum cleaners commonly have cleaning attachment tools that used for above-the floor cleaning operations, where the attachment tool is connected to a vacuum hose on a vacuum cleaner. When performing above-the-floor cleaning, surfaces to be cleaned in small, narrow and/or constricted areas are notoriously difficult to clean because many attachment tools are too large to fit into these areas. Crevice tools specifically developed for cleaning surfaces in small, narrow and/or constricted areas often fail as well since crevice tools are traditionally long, straight, and stiff, and cannot be fit into curved spaces very easily. More over, these crevice tools often require a user to bend over or stoop to achieve a proper orientation between the crevice tool and the surface to be cleaned, which can be painful to many users.

Flexible crevice tool for vacuum cleaners


A method, apparatus, and software are disclosed for collecting information relating to the execution of an application for use in analyzing the performance of the application. Probes are inserted at only those points in the application that would yield non-redundant information. As a result, the impact of the information collection process on the application is reduced, improving the usefulness of the collected information.

Computer software applications typically consist of many modules, known as functions, which work together to perform desired tasks. A significant concern in software development is operational speed, which is largely dependent on the performance of the individual functions making up the application. Thus, an important component of application development is monitoring application performance.
To provide useful information, performance measurement should, to the extent possible, avoid interfering with the normal operation of the application. Because performance measurement involves collecting data in circumstances under which data would not ordinarily be collected, performance measurement necessarily affects the normal operation of the application to a certain extent. Certain factors contribute to this effect. For example, inserting data collection code in an application makes the application larger, which slows operation down somewhat. This decrease in performance is attributable to the increase in the amount of code that must be both loaded into the system's memory and executed. In addition, adding data collection code increases the amount of time other operations take due to the execution of the data collection code. As a result, the time relationships between the other activities within the application and within the system are affected. Data collection also affects application performance as a result of input/output (I/O) bandwidth considerations. Specifically, when data is collected, it must be stored, for example, in physical memory, on a disk, or on a networked device. Storing data consumes significant time due to the relatively slow process of outputting data to the storage device. This burden is especially considerable when large amounts of data are collected. While the burden can be reduced by adding a dedicated I/O device, such as a disk drive, device contention may still arise at the system level.

Minimal instrumentation for lossless call profiling


An apparatus, system, and method are disclosed for annealing an ammunition cartridge that include an inductive coil, the inductive coil substantially encompassing the sides of an annealing chamber, the inductive coil including a first portion comprising a first diameter and a second portion comprising a second diameter, wherein the first diameter is larger than the second diameter. Apparatus, system and method may also include an insert, the insert encompassing the sides of the annealing chamber, and a cartridge case that is unevenly heated such that the cartridge case obtains at least a first hardness at a first location and a second hardness at a second location, the first hardness different from the second hardness.

Heating a metal object is often desired to change properties of the metal object. For example, heating a metal object may help to harden a metal, soften a metal, and/or reduce material stress within a metal. These various types of heat treatments are often referred to as annealing.
One particular metal object that is often heat treated is a cartridge case. Cartridge cases are generally processed in a mass manner. That is, each step of forming or preparing a cartridge case for use in an ammunition round is often performed substantially simultaneously on a large number of cartridge cases. For example, in cartridge case annealing processes a number of cartridge cases are often heated in an oven at the same time. After a step, such as an anneal step, the cartridge cases may be dumped into large bins for transfer to a separate location for the next step or process.

Apparatus, system, and method for ammunition cartridge case annealing


A flip-chip type integrated circuit chip including a chip die having electrical contacts arranged in a predetermined pattern and capable of providing electrical interconnection with a carrier substrate is provided. The chip die includes a fluxing agent disposed on a surface of the electrical contacts, and a curable thermosetting underfill composition distinct from the fluxing agent and disposed in a flowable form over the chip die. Upon mating of the chip die with the substrate and heating, the electrical contacts flow and the thermosetting underfill composition cures, thus adhering the chip die to the substrate, forming a circuit assembly.

1. Field of the Invention
The present invention relates to assemblies for connecting circuitry. More particularly, the invention relates to mounting assemblies and methods for providing electrical connection between electronic circuitry.
2. Brief Description of Related Technology
In recent years, the popularity of small-sized electronic appliances, such as camera-integrated video tape recorders and portable telephone sets, has made size reduction of large-scale integration desirable. As a result, chip size or chip scale packages are being used to reduce the size of packages substantially to that of bare chips. Such chip scale packages include a semiconductor chip mounted on a carrier substrate, which improves the characteristics of the electronic device while retaining many of the operating features, thus serving to protect semiconductor bare chips and facilitate testing thereof.
Upside down integrated circuits, commonly referred to as "flip-chips", are now gaining popularity as well. Flip-chips are manufactured using solder bump technology, in which solder bumps are deposited on solder-wettable metal terminations on a die or chip and a matching pattern of solder-wettable terminations on the substrate. With flip-chips, the solder bumps are placed on the integrated circuit terminals while the chip is in wafer form, and then, after singulation, a chip is flipped and aligned to the circuit board substrate. A fluxing agent is applied and the solder bumps are re-flowed by heating to establish bonding between the chip and the substrate, with all the joints being made simultaneously by melting the solder.
When the resulting circuit board assembly is exposed to thermal cycling, the reliability of the solder connection between the circuit board and the chip often becomes suspect. Commonly, after a chip is mounted on a circuit board, the space between the chip and the circuit board is filled with a sealing resin (often referred to as underfill sealing) in order to reinforce against stresses caused by thermal cycling. Such underfill encapsulation has gained considerable acceptance in the electronics industry, with epoxy-based resin materials being most commonly used in such applications. Moreover, the expansion coefficients of the underfill sealing can be adjusted, for example, by the addition of low thermal-expansion fillers, such as glass or ceramics, thus reducing the level of thermal stress that develops between the substrate and the underfill sealing. The underfill sealing thus provides structural reinforcement, which delocalizes the thermal expansion stress, thereby improving heat shock properties and enhancing the reliability of the structure.
Also, the underfill material helps adhere the chip to the substrate. As such, the underfill material should exhibit high cohesive strength to the die and the circuit board surface, and retain significant strength within the environment encountered by the electronic device, for example, during heat-up and cool-down cycles associated with on/off powering of the electronics, as well as climatic changes in temperature and humidity.
Application of underfill sealing typically involves dispensing the underfill material onto one or more edges of the flip-chip assembly after it has been assembled and the solder bumps affixed to the substrate. Capillary action draws the underfill material through the gap between the chip and the substrate. Such underfill techniques are time consuming, and complete filling of the underfill sealing between the chip and the substrate can be difficult to achieve, thus reducing the protection level afforded through the underfill sealing.
In an attempt to overcome these issues and to eliminate processing steps, underfill sealants incorporating fluxing agents for bonding of the solder bumps have been proposed. For example, U.S. Pat. Nos. 5,985,043 and 5,985,486 disclose polymerizable fluxing agents, which act as an adhesive to bond the chip to the substrate. Such polymerizable fluxing agents are based on polycarboxylic acids having olefinic linkages, compositions of that are curable upon exposure to heat. The thinking here is that the underfill sealant incorporating such polymerizable fluxing agents can be applied to the chip during the wafer stage of chip manufacture, often referred to as wafer-applied fluxing underfill, in which a plurality of chips are manufactured in one piece and later cut into individual chips. By pre-applying onto the wafer the fluxing agent/underfill sealant combination, the chip should only need to be placed on the substrate, with solder re-flow and underfill curing occurring to affix the chip thereto. In practice, however, including the fluxing agent and underfill sealant in a single composition tends to compromise adhesion and mechanical strength of the underfill sealant.
Further, in some applications, the desirability of component removal may be of a concern, for example, when chip failure occurs. To avoid destroying or scrapping the entire assembly, it has been proposed to include reworkable adhesive materials in the assembly process. Such reworkable adhesive materials may be used as the underfill encapsulant adhesive, thereby providing reworkability to enable removal and replacement of one or more defective die. Such reworkable underfill materials typically involve thermally cleavable epoxy-based polymers, which will decompose rapidly when exposed to a high enough temperature. For example, U.S. Pat. No. 5,948,922 (Ober) and U.S. Pat. No. 5,973,033 (Ober), each refer to a certain class of compounds and compositions based on such compounds which, when cured, provide decomposable compositions capable of being reworked.
U.S. Pat. No. 5,512,613 (Afzali-Ardakani), U.S. Pat. No. 5,560,934 (Afzali-Ardakani) and U.S. Pat. No. 5,932,682 (Buchwalter), each refer to a reworkable thermoset composition based on a diepoxide component in which the organic linking moiety connecting the two epoxy groups of the diepoxide includes an acid cleavable acyclic acetal group. With such acid cleavable acyclic acetal groups forming the basis of the reworkable composition, a cured thermoset need only be introduced to an acidic environment in order to achieve softening and a loss of much of its adhesiveness.
U.S. Pat. No. 5,872,158 (Kuczynski) refers to thermosetting compositions capable of curing upon exposure to actinic radiation, which are based on acetal diacrylates, and reaction products of which are reported to be soluble in dilute acid.
U.S. Pat. No. 5,760,337 (Iyer) refers to thermally reworkable crosslinked resins to fill the gap created between a semiconductor device and a substrate to which it is attached. These resins are produced by reacting a dienophile (with a functionality greater than 1) with a 2,5-dialkyl substituted furan-containing polymer.
International Patent Publication No. PCT/US98/00858 refers to a thermosetting resin composition capable of sealing underfilling between a semiconductor device including a semiconductor chip mounted on a carrier substrate and a circuit board to which said semiconductor device is electrically connected. The composition includes about 100 parts by weight of an epoxy resin, about 3 to about 60 parts by weight of a curing agent, and about 1 to about 90 parts by weight of a plasticizer. Here, the area around the cured thermoset is to be heated at a temperature of about 190° C. to about 260° C. for a period of time ranging from about 10 seconds to about 1 minute in order to achieve softening and a loss of much of its adhesiveness.
The additional chemistry built into such reworkable polymers to provide the ability to controllably degrade under appropriate conditions, however, oftentimes detracts from the overall effectiveness of the underfill sealing in terms of strength, adhesion, and moisture resistance.
U.S. Pat. No. 6,121,689 discloses a semiconductor flip-chip package, which includes a polymerizable fluxing agent. FIGS. 1 and 2 herein depict flip-chip structures as set forth in the '689 patent. As is apparent, the flip-chip structure of FIG. 1 includes a chip 10 having solder bumps 14 pre-assembled on contact pads 24 on bottom surface 16 of chip 10 for electrical connection with solder pads 12 of a substrate 20 through the use of an encapsulant 22. In further embodiments, a fluxing adhesive may be used to adhere the chip 10 to the substrate 20. Moreover, as shown in FIG. 2, the structure may also include a multi-layer encapsulant material 36, including attachment and stress distribution layers 38 and 40, and thermoplastic reworkability layer 42. This thermoplastic reworkability layer is generally a meltable polymer such as a polyimide-siloxane copolymer. As shown in FIG. 2, flux adhesive 34 may be provided between the chip 10 and the substrate 20 for attachment of the chip 10 to the substrate 20. Adhesion and mechanical strength of the underfill sealant may be compromised due to the incorporation of the fluxing agent and the adhesive in a single composition. Also, when an integrated circuit chip includes an encapsulant having a fluxing adhesive incorporated therein, the fluxing adhesive may adversely affect the encapsulant material, thereby reducing the shelf stability or pot-life. Also, the use of a thermoplastic material as the reworkability layer provides the assembly with limited rework properties.
Notwithstanding the state of the art, it would be desirable for an integrated circuit chip having an underfill sealant material which provides excellent adherence and thermal shock properties while allowing the substrate with which it is to be used to be readily processed without compromising the physical properties of the materials or the assembly.

Wafer applied fluxing and underfill material, and layered electronic assemblies manufactured therewith


The present invention relates to a novel polysilane composition and, more specifically, to a polysilane composition that is soluble in organic solvents, that has a molecular weight in the range of 2,000 to 1,000,000, and that has a short-wavelength (.ltoreq.285 nm) absorption maximum at room temperature.

The present invention relates to a novel polysilane composition and, more specifically, to a polysilane composition that is soluble in organic solvents, that has a molecular weight in the range of 2,000 to 1,000,000, and that has a short-wavelength (.ltoreq.285 nm) absorption maximum at room temperature.
Polysilanes are currently under investigation as conductive materials, photoconductive materials, nonlinear optical materials, and photoresists. However, since these materials generally absorb in the 300 to 400 nm region, the exploitation of their nonlinear optical properties requires polysilanes that absorb at shorter wavelengths. Moreover, utilization as a deep UV patterning material also requires polysilanes that absorb at shorter wavelengths. To date, the soluble high-molecular-weight polysilane with the shortest absorption wavelength is (3,3,3-trifluoropropyl)methylpolysilane EQU --[CF.sub.3 CH.sub.2 CH.sub.2 (CH.sub.3)Si].sub.n --
as described by Masaie Fujino, et al., Macromolecules, Volume 25, p. 1079, (1992).
The present invention takes as its object the introduction of a high-molecular-weight polysilane that absorbs at shorter wavelengths and is also soluble in organic solvents.


A semiconductor device of the present invention comprises a first semiconductor chip that includes a first internal circuit and at least one first conductive pad which is provided on its upper surface and is not connected to the first internal circuit, a second semiconductor chip provided on the first semiconductor chip that includes a second internal circuit and at least one second conductive pad which is provided on its upper surface and is connected to the second internal circuit, at least one first connecting member for connecting between the second semiconductor chip provided on the first semiconductor chip, at least one first conductive pad and at least one second conductive pad, and at least one second connecting member led from at least one first conductive.

The present invention relates to a semiconductor device that a plurality of semiconductor chips are integrally structured and in particular to, facilitation of design for the semiconductor device.
A semiconductor device with a plurality of semiconductor chips being integrally structured therein is conventionally designed so that pads for the semiconductor chips are connected together by utilizing wire bonding connection or flip chip connection.
A conventional semiconductor device with a plurality of semiconductor chips being integrally structured therein will be described hereinafter.
FIG. 27 is a view showing the structure of a conventional semiconductor device with a plurality of semiconductor chips being integrally structured therein. FIG. 28 is a cross-sectional view taken along a line X-X shown in FIG. 27.
As shown in FIGS. 27 and 28, a semiconductor device 1000 comprises a semiconductor chip B, a semiconductor chip A which is adhered on the semiconductor chip B with an adhered portion being interposed therebetween and wires 11, 12, 13, 14, 15, 16, 21, 22, 23, 24, 25 and 26 extended from pads for the semiconductor chips A and B by wire bonding.
The wires 13, 15, 23 and 25 connect the pads for the chip A to the pad for the chip B. The wires 12, 14, 22 and 24 connect the pads for the chip A to electrodes outside the semiconductor device 1000 (e.g., lead frame, electrode pad for printed wiring board and the like). The wires 11, 16, 21 and 26 connect the pad for the chip B to external of the semiconductor device 1000.
There arise following various problems in designing and manufacturing the conventional semiconductor device 1000.
Firstly, as shown in FIG. 28, in accordance with the conventional semiconductor device 1000, a maximum distance h from the wire 12 or 22 to the upper surface of the semiconductor chip B is extremely long. Further, portions of the wires 12 and 22 that are not connected to pads are long. For this reason, the wires 12 and 22 are easily bent by an external stress. Consequently, when the wires are provided and then the semiconductor device 1000 is to be worked, the wires 12 and 22 and the wires 11 and 21 may be shorted. As a result, yield rates for products obtained by working the semiconductor device 1000 may be decreased.
Moreover, since the positions of the pads for the semiconductor chips A and B are fixed in the conventional semiconductor device 1000, a degree of freedom in wiring design is low.
In accordance with the conventional semiconductor device 1000, wires for connecting the semiconductor A to the semiconductor B (e.g., the wires 12 and 14) may have different lengths. Thus, such wires may have various delay values.
The semiconductor chip B does not have marks for fixing the semiconductor A thereon. Thus, when the conventional semiconductor device 1000 is manufactured, it is difficult to adhere the semiconductor chip A on the semiconductor chip B so that the semiconductor chip A is securely fixed on a predetermined position of the semiconductor chip B.
When the semiconductor chip A and other semiconductor chip with the same size as the semiconductor chip A are adhered on the semiconductor chip B, the semiconductor chip A may be mistaken for the other semiconductor chip.
The semiconductor chip A is provided with only pads for wire bonding. Thus, the semiconductor chip A is connected to the semiconductor chip B only by wire bonding.
In accordance with the conventional semiconductor device 1000, since the space between the semiconductor chips A and B is not shielded at a ground potential, EMI (Electro Magnetic Interference) may occur thereat.

Semiconductor device, method for designing the same and recording medium that can be read by computer in which program for designing semiconductor device is recorded


Various methods and apparatuses involving salt-based compounds and related doping are provided. In accordance with one or more embodiments, a salt-based material is introduced to a semiconductor material, and is heated to generate a neutral compound that dopes the semiconductor material. Other embodiments are directed to semiconductor materials with such a neutral compound as an impurity that affects electrical characteristics therein.

Electronic devices, such as organic thin-film transistors (OTFTs) and other organic semiconductors (OSCs) have attracted a great deal of attention because of their potential applications in low-cost, large-area and flexible electronics. Organic semiconductors are commonly referred to as either p-channel (hole-transporting) or n-channel (electron-transporting) depending on which type of charge carrier is dominant for the charge transport.
While organic semiconductors have been readily implemented for a variety of applications, both p-channel and n-channel organic semiconductors have been challenging to manufacture and implement in the context of various applications. For instance, the energetically high-lying lowest unoccupied molecular orbital (LUMO) levels in most organic semiconductors hinder the efficient injection of electrons. n-Type doping can be applied to increase the electron density and improve the electron injection in semiconductor devices. In n-channel OTFTs with efficient doping, electrons can be transferred from the high-lying highest occupied molecular orbitals (HOMOs) of dopants to the LUMOs of organic semiconductors by n-type doping. However, such dopants are susceptible to oxidation in air.
While various n-type dopants have been used with organic semiconductors, many have been challenging to implement. For example, alkali metals are prone to diffuse through organic layers due to their relatively small atomic radii, leading to device instability. In addition, alkali metals are difficult to process. Other dopants having both extremely high-lying HOMO levels and exhibiting air stability do not provide donors that are strong enough to obtain sufficient conductivity. In addition, the accessibility and implementation of dopants exhibiting low-lying LUMO energy levels has also been limited, and in particular for organic applications.
These and other issues remain as a challenge to a variety of methods, devices and systems that use or benefit from semiconductors.

Semiconductor materials, apparatuses and methods

The Board of Trustees of the Leland Stanford Junior University


Disclosed is use of nonsteroidal anti-estrogen compounds such as toremifene citrate as active ingredient for treating autoimmune diseases.

Immunosuppressants, nucleic acid antagonists, antimetabolites, etc., are used in the medicinal treatment of autoimmune diseases today. Anti-inflammatory agents, anticoagulants, etc., are also used in the symptomatic therapies of the diseases. The effects of these agents are, however, not yet sufficient.
It is known that the immunosuppressants have side effects of provoking diabetes, renal disorders, infectious diseases, etc. Also the use of the nucleic acid antagonist or antimetabolite is frequently accompanied by side effects such as hepatic disorders and medullary disorders. Thus the medicinal treatment of autoimmune diseases is so far very insufficient.
It has been demanded to develop a remedy for autoimmune diseases which acts on the immune system and which has a function mechanism different from that of conventional drugs for the diseases and less serious side effects.


A dynamic process for increasing the wear life of ferrous articles subjected to a high-temperature environment created by combustion of a propellant or fuel comprises selecting the propellant or fuel so that its combustion products include relatively large amounts of nitrogen, which nitrogen forms a protective nitride layer on the surface of the ferrous article. Disclosed is a specific embodiment of the invention for prolonging the wear life of gun barrels.

Gun barrels, turbine components, internal combustion engine components, aerospace components, chemical reactors, machine tools, drilling equipment, bearings and the like are often comprised of iron, steel or other ferrous alloys. In use, such articles are frequently exposed to various combinations of high-temperature, high-pressure and corrosive ambient environments. These conditions can cause thermochemical erosion of the substrate materials leading to pitting, cratering, cracking and failure.
The prior art has recognized such problems and has attempted to prevent or minimize the erosion of ferrous materials by the use of various coatings comprised of high hardness materials. For example, U.S. Patent Application Serial No. 2002/0104588 discloses a process for extending the life of mechanical centrifuge screens by forming a layer of high-hardness iron nitride on the screen and subsequently electroplating a layer of chromium onto the nitride layer. The nitride layers of the '588 application are high-hardness layers including at least 33 atomic percent nitrogen. Likewise, U.S. Pat. Nos. 5,887,558 and 5,810,947 show coatings of high-hardness iron nitride used in connection with internal combustion engines and machine tools respectively. As will be explained in detail hereinbelow, such prior art methods have been found to be unsuitable for, and in some instances actually derogatory to, enhancing the thermochemical stability of steel and the like under high-temperature, high-pressure reactive conditions.
The present invention may be utilized to enhance the thermochemical stability of a variety of articles. For the purposes of this present discussion, the invention will be described primarily with regard to gun barrels; however, it is to be understood that the invention may be used with equal advantage in connection with any other articles which are exposed to conditions which include one or more of high-temperature, high-pressure and corrosive environments. These articles include, by way of illustration and not limitation, internal combustion engine components, turbine components, aerospace assemblies, chemical reactors, machine tools, drilling equipment, bearings and the like.
Referring now to FIGS. 1A-1C, there is shown a cross-sectional view of a portion of a gun barrel 10 of the prior art showing various stages in a process leading to its thermochemical erosion. The gun barrel 10 of FIGS. 1A-1C is typical of, and representative of, barrels associated with relatively large artillery pieces as well as small arms. The gun barrel 10 is comprised of a body of steel alloy, and a portion of this body of steel alloy is shown in these figures at reference numeral 12. It is to be understood that in some instances gun barrels are fabricated as composite members having a steel liner which defines the gun bore, and this liner is encased in the body of another material such as a body of metal or a body of a reinforced polymer.
Referring now to FIG. 1A, it will be seen that the barrel 10 includes a coating of chromium 14 deposited on the surface of its bore. This chromium layer 14 is of high-hardness and increases the wear resistance of the barrel 10. It is to be understood that in some instances, the barrel may have a layer of a different refractory material thereatop, or may not have any refractory material at all. The present invention may be used in any of these types of gun barrels. As is shown in FIG. 1A, the layer of chromium 14 includes a number of cracks 16a, 16b defined therein. These cracks pass through the layer of chromium 14 and expose portions of the surface of the underlying steel alloy 12. Also, it will be noted that a portion of the layer of chromium 14 is flaked away creating a large open area 16c which exposes the underlying body of steel 12. Cracking and flaking can occur as a result of stresses which arise when the chromium is deposited, and further cracking and flaking can occur during the use of the gun. Similar cracking and flaking can occur with other refractory layers used for this purpose.
In use, the gun barrel 10 is exposed to a high-temperature, high-pressure corrosive atmosphere created by the propellant gases generated when the gun is fired. These gases include large amounts of CO and CO2 therein together with volatile acids, sulfur-containing compounds, and the like. These reactive gases can be in the form of ions, radicals or neutral species. The cracks 16a, 16b and void 16c will permit these reactive gases to contact the underlying body of steel 12 so as to cause a chemical reaction to occur between the components of the propellant gas and the steel. For example, it has been demonstrated that CO can react with the steel of gun barrels, under firing conditions, to cause carburization of the steel. As is shown in FIG. 1B, this reaction has created carburized regions 18a-18c in the steel 12.                Carburization can adversely change the properties of the steel. For example, a typical gun steel has a melting point of approximately 1723° K; however, if the steel is carburized, its melting point drops to 1423° K. The lowering of the melting point makes carburized portions of the barrel prone to pitting and other erosion as a result of the continuing use of the barrel.
As is shown in FIG. 1C, the carburized regions of FIG. 1B have eroded away producing pitted regions 20a, 20b, 20c in the steel 12. As will be seen, these pitted regions 20 have undercut portions of the chrome layer 14 which can lead to further cracking and flaking of that layer. In addition, the relatively rough surface of the pitted regions 20 is highly prone to further carburization and erosion. Similar reactions can also occur in engines, turbines and the like under high-temperature and/or high-pressure conditions.
Clearly there is a need for a method for stabilizing iron, steel and other ferrous alloys against thermochemical corrosion which can occur under severe use conditions. Such methods should be simple to implement and should not interfere with the function of the item. As will be explained in greater detail hereinbelow, the present invention provides a method for enhancing the resistance of ferrous materials to thermochemical erosion. The method of the present invention is unique insofar as it is a dynamic method; that is to say, it is a method which can be implemented while the article is in service. The method of the present invention does not require any pretreatment of the article, nor does it require any modification of the function or operation of the article. These and other advantages of the present invention will be described in detail hereinbelow.

Dynamic process for enhancing the wear resistance of ferrous articles

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


Methods and apparatus for controlling latency variation of packets received in a packet transfer network are provided. A plurality of packets is received at a network element of a receive node of the packet transfer network. A time-stamp is provided for each of the plurality of packets. An egress delay time is computed at a scheduler of the network element for each of the plurality of packets in accordance with each corresponding time-stamp to provide a substantially constant latency for the plurality of packets upon egression from the network element.

Various services in the Telecom network rely on a low latency variation transfer to ensure proper operation. Such services among others include synchronization and multi-media services (voice and video). Currently, with the prevalence of layer-3 and layer-2 packet networks, such as Internet and Ethernet, cost can be reduced by transmitting timing synchronization and voice service, as well as distributing video service between telecom equipment within the packet network. However, due to the store-and-forward operation of packet networks, those services will experience an uncertain delay, which will affect the accuracy of in-time delivery. This uncertainty in delay is commonly referred to as packet delay variation (PDV).
In addition to its effect on timing synchronization signals, PDV also has a significant effect on packets transferring voice and video data. It is desirable for packets transferring voice data to have a minimum, and above all, a well controlled, latency or delay, thus a substantial reduction or elimination of PDV is required. However, the amount of latency or delay does not carry a similar importance, since it is more important for the latency or delay to remain constant throughout the transfer. Therefore, it is desirable to at least significantly reduce or eliminate PDV for both timing synchronization signals and data packets in packet transfer networks.
Previous attempts to solve the problem of PDV and provide a predictable latency have included best effort forwarding in conjunction with traffic engineering as well as protocol specific manipulation of time-stamps. However, the traffic engineering of network nodes results in under-utilization of an expensive node.
Additional attempts have included work-conserving and non-work-conserving scheduling at an egress port upon reception of transferred packets. Work-conserving scheduling selects and schedules egression as soon as a previous egression is completed, while non-work-conserving scheduling selectively provides egression breaks for short, controlled periods of time. However, such scheduling methods have failed to involve real-time knowledge regarding the exact point in time when a packet would need to leave the device based on its arrival time. Thus, the scheduling methods fail to provide a jitter-bound behavior.
Regarding time-stamp-based packet synchronization methods, such as, for example, IEEE 1588, two techniques for providing timing synchronization with reduced PDV are known. These techniques include probabilistic filtering algorithms and long time averaging.
A probabilistic filtering algorithm filters out any large packet delays and uses the small packet delays for calculation of correction factors and timing synchronization of a local clock of a receive node with a transmit clock of a transmit node. This method usually has high complexity. The process of obtaining satisfactory small delays for calculation is random, therefore, successful performance of the probabilistic filtering algorithms in the short-term is not guaranteed.
Long time averaging provides a method that averages the delay of multiple transferred packets in order to eliminate the PDV. However, in an actual system, obtaining an absolute time is difficult because the local clock of the receive node is not accurate and requires synchronization. Any adjustment of the local clock may adversely affect the result of the delay averaging. Moreover, this method is not flexible, in that the result of the averaging cannot be controlled.
For a multitude of network services, such as, for example timing over packet (ToP) services, it is desirable to achieve a deterministic per-hop behavior that defines the policy and priority applied to a packet when traversing a hop. More specifically, the deterministic per-hop behavior may be considered a determination of a predictable latency at network elements, such as, for example, switches, routers or multiplexers, which may be particularly useful for timing synchronization over packet networks.

Methods and apparatus for controlling latency variation in a packet transfer network


The invention concerns an iron powder for fortifying foodstuff. The powder consists of a reduced iron powder having irregularly shaped particles, wherein the iron powder has a ratio AD:PD less than 0.3, wherein AD is the apparent density in g/cm3, and PD is the particle density in g/cm3. The specific surface area of the powder particles is above 300 m2/kg as measured by the BET method and the average particle size is between 5-45 μm.

Iron is an essential trace element in animal and human nutrition. It is a component of heme in hemoglobin and of myoglobin, cytochromes and several enzymes. The main role of iron is its participation in the transport, storage and utilization of oxygen. A balanced diet will normally cover the need of iron through intake of iron rich food stuff such as vegetables, meat and cereals. An important iron source is cereals such as wheat flour. However in modern methods of producing wheat flour the iron rich shell of the wheat grain is eliminated. This results in that the iron content of wheat flour of today is lower than that of wheat flour produced before. Iron deficiency is also a consequence of the malnutrition which is pre-vailing especially in the developing countries. As a diet with too low iron content contributes to low birth weights impairs growth and cognitive development in children and causes fatigue among adults there is a need of adding iron to the diet. The greatest effect of an iron fortification program will of course be reached when iron is added to food that most people eat daily.
The most widespread method is iron fortification of cereal products such as wheat flour, corn flour, corn flakes etc. but many other products are also fortified.
Iron can be added to food and feed in many different forms. Metallic iron can be used as well as inorganic salts of iron, such as iron sulphate, and organic salts, such as iron gluconate or iron fumarate. There are basically three different types of elemental iron for food fortification, namely reduced iron or sponge iron, carbonyl iron and electrolytic iron.
The reduced iron is produced by a reduction of ground iron oxide with hydrogen or carbon monoxide at elevated temperature followed by grinding and milling of the reduced iron cake. Reduced iron is produced from either iron ore or mill scale. The purity of the product is dictated by the purity of the iron oxide. These products have the lowest purity of the food grade iron powders when compared with-electrolytic or carbonyl powders. The most common impurity in iron powder produced by any reduction process is oxygen, most of which occurs as a thin film of surface oxide. Basic impurities include carbon, magnesium, aluminium, silicon, phosphorus, sulphur, chromium, manganese, nickel and copper, many of which are present as oxides. The particle size is irregular and porous and it consists of a number of small equiaxed grains.
Carbonyl iron powders consist of particles, which are much finer than particles of other iron powders. These powders are produced by treating reduced iron with carbon monoxide under heat and pressure. The resulting iron pentacarbonyl is later decomposed under controlled conditions yielding an iron powder and carbon monoxide gas. At this point the major impurity is carbon and further reduction in wet hydrogen is necessary to remove most of the carbon. The powder has particles ranging in size from 0.5 to 10 μm in diameter and is of high purity. The particles are close to spherical in shape and very dense and smooth. The structure of the particles is characterized by concentric shells arranged in onion-skin fashion. The carbonyl process is costly.
Electrolytic iron is produced by electrolytic deposition of a hard brittle metal that is mechanically comminuted. The particle shape of electrolytic iron powder is irregular, dendritic of fernlike, from which it receives its high surface factor.
An important feature for the iron containing compounds used as food additive is the bioavailability of the iron i.e. how efficiently the iron is absorbed by the body. Of the iron powders used for food and feed enrichment today, the carbonyl and electrolytic powders have the highest bioavailability but the production costs of these powders are high compared with the production costs for reduced iron powders. A pure reduced iron powder, which has high bioavailability and which can be cost effectively produced would therefore be attractive and is the object of the present invention.
The assessment of bioavailability may be performed in different ways such as in vitro studies, animal studies or human studies. Bioavailability of iron powders as well as other iron compounds are usually measured relative to iron sulphate.


A powertrain for transmitting power to a driven wheel of a motor vehicle includes a power source that includes a reversible electric machine. A first transmission includes an input driveably connected to the power source, a first output, and a mechanism for producing a stepless variable range of ratios of a speed of the output to a speed of the input. An epicyclic transmission includes a second input driveably connected to the power source, a third input driveably connected to the first output, and a second output driveably connected to a drive wheel. The transmissions produce a range of speed of the drive wheel that varies from negative to positive and includes zero.

This invention relates generally to hybrid powertrains for motor vehicles having two power sources or prime movers, such as an electric motor and internal combustion engine. In particular, the invention pertains to a powertrain that provides the driver with an acceptable response to a command for a change in wheel torque even though the prime mover is slow to respond to the command.
Hybrid electric powertrains for motor vehicles include at least two power sources or prime movers, an electric motor or motor/generator, accessible to an electric storage unit such as a battery, and an engine, such as an internal combustion engine supplied from a fuel source. Powertrains for another type of motor vehicle, electric drive, include one power source, an electric motor or motor/generator supplied from an electric storage battery.
The electric machine systems for either type of powertrain may use a battery, flywheel, capacitor, fuel cell, or other energy storage devices. The engines in hybrid powertrains may be gasoline, diesel, or other fuel-based combustion systems.
The rotational speed and torque states of a hybrid electric powertrain having either a step ratio transmission or fixed-span continuously variable transmission cannot be transiently isolated from the speed and torque states of the driveline and wheels demanded by the operator. This lack of isolation imposes constraints on the efficient use of hybrid electric, kinetic energy storage systems.
Certain types of internal combustion engines and fuel cell systems can provide high efficiency and low emissions, but with relatively slow transient load and speed response. This slow transient response is unacceptable for vehicles with conventional drivelines.
Certain types of transmissions provide acceptable vehicle transient response even when used in combination with slow transient response engines. The basic features of these transmissions include an infinitely variable drive ratio, and reversible torque machines with energy storage. An infinitely variable transmission (IVT) is a transmission that produces an infinite speed ratio span and continuous speed ratio variation.
Internal combustion engine development has been concentrated on efficient power sources such as engines and combustion systems that produce low exhaust gas emissions. Gasoline engines that use homogeneous charge compression ignition (HCCI) combustion show potential to operate as efficiently as a diesel engine, yet emit a very low volume of NOx compounds in the exhaust gas. However, on a fixed compression ratio basis, a HCCI combustion system is five to ten times slower in response to load changes than a stoichiometric, port fuel injected, spark ignited combustion system, the current production baseline engine.
Slow dynamic engine response requires both speed isolation and load isolation to produce acceptable performance. The key powertrains for producing speed and load isolation include series electric, series hybrid, power-split electric and power-split hydraulic. The prime mover would be suitably decoupled from the drive wheels, as in most conventional high power hybrid powertrains.
An energy storage media onboard the vehicle supplements energy derived from engine fuel. The energy storage media must be capable of powering the vehicle for the length of the period while the prime mover is adjusting to the new load state, generally about one to five seconds. Both hydraulic and electric hybrid architectures may be used to provide the auxiliary energy storage.
Energy stored in hydraulic fluid accumulators, electric batteries, capacitors, or flywheels can be used in combination with reversible machines, such as hydraulic pump/motors and electric motors, to accelerate the vehicle in response to the driver's demand for increased wheel torque, while the prime mover is moving from an idle state to a full load state. The stored energy reserve can be recovered from regenerative wheel braking or it can be produced by the prime mover while road load is low.
There is a need to provide a powertrain having components that compensate for the inherently slow dynamic response of a prime mover such as an IC engine or other power source to provide the operator with an acceptable, timely response to speed and load transient demands.

Electric and hybrid electric powertrain for motor vehicles


A mirror file systems (MFS) is a virtual file system that links two or more file systems together and mirrors between them in real time. The file systems linked and mirrored through the mirror file system can be a local file system connected to a physical device, or a network file system exported by a remote system on a network. The mirroring mechanism is established by linking a file system to another file system on a single directory through an MFS mounting protocol. User applications perform normal file system operation and file/directory operation system calls like open, read, write and close functions from the pathname of either file system. When updates occur, such as a write operation, the MFS mechanism ensures that all data updates go to both the file systems in real time.

In a computer network environment, hundreds or even thousands of computer systems may be connected by a communication channel. They can all communicate with each other through many different communication protocols. Each protocol has a particular way to link the systems together to transmit data from one to another. To help the systems cooperate more closely, resource sharing mechanisms have been developed to allow computer systems to share files across the computer network. One example of such a mechanism is the client-server Network File System (NFS) developed by Sun Microsystems. By sharing the files across the network, every client system on the network can access the shared files as if the files were local files on the client system, although the files may be physically located on and managed by a network server system at a remote location on the network. The file sharing provided by the NFS enhances the network operation with the following features:                a. Each client system no longer needs to physically keep a local copy of the files.        b. Every client system can access the shared files in the same manner as it accesses its own local files.        c. There is only one copy of files located on and managed by a network server, so it is always the only version and always up-to-date.
This file sharing provided by the NFS works well in a small or middle size network environment. As more client systems are added to the network, and more subnets are connected to the network, more routers and switches are needed to interconnect many different small networks or sub-networks to form a large network. A network server that shares its files across such a network to the client systems faces the following problems:                1. The network server is loaded heavily by increasing requests from many client systems on the network. To alleviate the load problem, the network server can be upgraded to add more CPUs on the system, and the storage devices which store the shared information can also be upgraded to provide more bandwidth on their data channels, so that requests for the information from client systems on the network can be serviced without delays.        2. The network is congested with the traffic generated by the client systems' requests from all different directions and the server's return. To alleviate the congestion problem, the bandwidth of network communications media can be increased to accommodate more traffic and faster routers and/or switches can be added to transfer data packets faster on the network.
By using more CPUs on the system, faster data channels on the storage media, increased network bandwidth, and adding faster routers and/or switches, the overloading problem on the network server and the traffic congestion problem on the network are reduced to some degree. But this single centralized network server configuration and topology still faces other problems:                3. If the storage device that stores the shared files is not available due to a) power outage, b) hardware failure, or c) scheduled maintenance, then the network clients that depend on the network server to store and to retrieve critical information from the shared files on that storage device will not function properly. To reduce the risk from such disasters, a disk array technology known as RAID (Redundant Array of Independent Disks) was developed to minimize the damage and more easily recover from failure due to the above mentioned situations. The RAID disk array technology can protect the files on the disk from damage or corruption by using the techniques of striping, mirroring and parity checking, etc. But this only protects the storage system, and not the network server.        4. If the network server goes down for any reason, it cannot store or retrieve critical information for the network clients. To deal with the problem caused when a network server goes down, the following two computer systems were designed:                    a. Fault-tolerant computer systems that require duplicate copies of every hardware component in the system as stand-by parts.            b. Clustering systems which have more than one network server physically connected to the same storage system on which the shared files are located. All these network servers (or nodes) are running at the same time, but only one of them actually serves the clients' requests; the others function as stand-bys. When the primary server is down, a stand-by server kicks in and takes over the operation.
With more CPUs on the system, RAID disk arrays, fault-tolerant computer systems and clustering network systems, many of the problems that are associated with sharing files by means of a server on the network seem to be overcome or reduced. However, in contrast to these expensive and cumbersome hardware solutions, a simpler and better way to achieve the same results is through a software solution.
The root cause of the problems mentioned previously is the fact that there is only a single copy of shared files stored on the disk of the network server. The advantage of keeping one single copy of the shared files on the network is that it is easy to maintain and update the files. However, since there is only one copy of the shared files on the network, the following disadvantages result:                1. All clients systems on the network have to send their requests through multiple routers and/or switches before they reach the network server. Consequently, the network server is overloaded and the network becomes congested.        2. No network can afford to let this single copy of shared information become unavailable, so a disk array with a RAID level is needed to protect the sole copy of files on the disk from becoming unavailable.        3. In addition to using the disk array to protect the shared information on the disk, a fault-tolerant system or clustering system is also needed as protection against network server failures, which can result from failures in any of several key components as well as from failure of the network server itself.