Abstract: A communication cable includes at least one twisted wire pair formed by twisting a plurality of insulation-coated wires; a sheath surrounding the twisted wire pair; and a protrusion formed on an outer surface of the sheath. This communication cable may prevent alien crosstalk particularly at high-speed transmission so that transmission characteristics of the communication cable may be stably kept.

Abstract: The layout of latches in a common clock domain is efficiently optimized to shrink the physical size of the domain while maintaining timing requirements. The latches are placed in a first layout preferably using quadratic placement, and a star object is built representing an interim clock structure. The latches are weighted based on wire distance from a source of the star object, and then re-placed using the weighting. The weighted placement and repartitioning may be iteratively repeated until a target number of bins is reached. The boundary of the latches in the final global placement is used to define a movebound for further detailed placement.

Abstract: A computer implemented method and a computer program product which perform cell transforms that decrease overall wire length, without degrading device timing or violating electrical constraints. The process computes delay constraint coefficients for a data set. The process performs a detailed placement transform by moving a subset of cells, making the placement legal, computing a half perimeter wire length change for each output net that is a member of the subset of nets, and computing a Manhattan distance change for each source-sink gate pair within the move cells. The process computes a weighted total wire length incremented value for the transformed data set, if the move will not improve placement, the move transform is not allowed. Further, the process continues by evaluating arrival time constraints, electrical constraints and user configurable move limits for violations, restoring the move cells to the original placement if a violation is found.

Abstract: A method of force directed placement programming is presented. The method includes sorting objects of a netlist for placement by magnitude of their spreading force and selecting a plurality of the objects. The method further includes waiving (or nullifying) the spreading force for the selected objects in a subsequent non-linear program solver step of the force directed placement program. The positions of the objects after the subsequent non-linear program solver step are based only on their connections to other objects in the netlist. The selected objects no longer retain their relative ordering as obtained during a previous non-linear program solve step of the force directed placement program. An alternative method of force directed placement programming is also present, which includes identifying objects from a netlist for placement that have a very high spreading force magnitude.

Abstract: A micro coaxial cable includes an inner conductor; an insulation layer having foaming cells and formed to surround the inner conductor; an over-foaming preventing layer formed to surround the insulation layer for the purpose of uniform forming of the foaming cells; a metal shield layer formed to surround the over-foaming preventing layer; and a protective coating layer formed to surround the metal shield layer. The over-foaming preventing layer restrains abnormal growth of foaming cells formed in the insulation layer such that the foaming cells are successively adjacently formed with uniform size. Due to the uniformity of foaming, the dielectric constant of the insulation layer is not locally different but uniform as a whole, thereby capable of improving transmission characteristics. In addition, the micro coaxial cable enables to transmit signals even at a high frequency transmission of GHz range, which was impossible in the prior art.

Abstract: A separator for a communication cable includes a plurality of barriers formed in a radial direction so that at least two pair units, in each of which at least two insulation-coated wires are spirally twisted, are received in spaces formed by the barriers one by one so as to separate the pair units from each other. At least one of the barriers has a relatively greater thickness than the other barriers. Thus, a communication cable having the separator may prevent PSNEXT (Power Sum Near and Crosstalk) caused by interference between adjacent wires when a high frequency signal is transmitted through the wires.

Abstract: A placement technique for designing a layout of an integrated circuit by calculating clustering scores for different pairs of objects in the layout based on connections of two objects in a given pair and the sizes of the two objects, then grouping at least one of the pairs of objects into a cluster based on the clustering scores, partitioning the objects as clustered and ungrouping the cluster after partitioning. The pair of objects having the highest clustering score are grouped into the cluster, and the clustering score is directly proportional to the total weight of connections between the two objects in the respective pair. The clustering scores are preferably inserted in a binary heap to identify the highest clustering score. After grouping, the clustering score for any neighboring object of a clustered object is marked to indicate that the clustering score is invalid and must be recalculated. The calculating and grouping are then repeated iteratively based on the previous clustered layout.

Abstract: A communication cable includes at least two pair units in each of which at least two insulation-coated wires are spirally twisted; a separator having a barrier for separating the pair units from each other; an outside jacket surrounding the separator and the pair units separated by the separator; and a plurality of jacket spacers provided to an inner surface of the outside jacket to separate the pair units from outside by a predetermined distance. Thus, the communication cable may prevent crosstalk generated when a high frequency signal is transmitted.

Abstract: Disclosed is an optical cable with a secondary sheath for surrounding and protecting a plurality of optical fiber units in which at least 1-core optical fiber is mounted in a buffer tube, wherein the secondary sheath is made of a mixture including 100 parts by weight of base resin selected from the group consisting of low density polyethylene, linear low density polyethylene, and their mixture; and 0.2 to 60 parts by weight of inorganic additive. The secondary sheath of this optical cable shows excellent cutting and tear characteristics and ensures easy contact and divergence.

Abstract: A communication cable includes at least one twisted wire pair formed by twisting a plurality of insulation-coated wires; a sheath surrounding the twisted wire pair; and a protrusion formed on an outer surface of the sheath. This communication cable may prevent alien crosstalk particularly at high-speed transmission so that transmission characteristics of the communication cable may be stably kept.

Abstract: A communication cable includes a separator prepared in the cable for preventing alien crosstalk, and at least one spacer integrally formed with the separator at a side of the separator contacting with an outside jacket. The spacer forms a protrusion protruded out on the cable, and this protrusion makes the transmission wires in the cable be spaced apart from adjacent cables. Thus, alien crosstalk generated due to proximity of other cables during high frequency signal transmission may be prevented.

Abstract: A separator for a communication cable includes a plurality of barriers formed in a radial direction so that at least two pair units, in each of which at least two insulation-coated wires are spirally twisted, are received in spaces formed by the barriers one by one so as to separate the pair units from each other. At least one of the barriers has a relatively greater thickness than the other barriers. Thus, a communication cable having the separator may prevent PSNEXT (Power Sum Near and Crosstalk) caused by interference between adjacent wires when a high frequency signal is transmitted through the wires.

Abstract: A UTP (Unshielded Twisted Pair) cable having an electromagnetic wave shielding function is configured to allow transmission of over 10 Gbps level without align cross talk with an adjacent cable when using 500 to 700 MHz band. This UTP cable includes at least one wire pair in which two insulation-coated wires are spirally twisted, an electromagnetic wave shielding sheath surrounding the wire pair and made of polymer resin and conductive material, and an insulating sheath surrounding the electromagnetic wave shielding sheath and made of insulating material.

Abstract: A method of assessing the stability of a placement tool used in designing the physical layout of an integrated circuit chip, by constructing different layouts of cells using the placement tool with different sets of input parameters, and calculating a stability value based on the movement of respective cell locations between the layouts. The stability value can be normalized based on cell locations in a random placement. One stability metric measures absolute movement of individual cells in the layouts, weighted by cell area. The cell movements can be squared in calculating the stability value. Another stability metric measures the relative movement of cells with respect to their nets. Shifting of cells and symmetric reversal of cells about a net center does not contribute to this relative movement, but spreading of cells and rotation of cells with respect to the net center does contribute to the relative movement. Relative cell movements can again be squared in calculating the stability value.

Abstract: Disclosed are an optical fiber unit in which at least 1-core optical fiber is mounted in and protected by a buffer tube, and an optical cable including the optical fiber unit. The buffer tube is made of a mixture, which includes a composite resin including a resin selected from polyolefin polymer, nitrile rubber and their mixture, and plasticized polyvinylchloride; and an inorganic additive, wherein, in a stress-strain curve of the buffer tube, a modulus is 5 to 50 kgf/mm2 in a linear region with an elongation less than 1% and a tan ? is less than 0.5 at 30° C. The buffer tube of the optical fiber unit may be very usefully applied to an optical cable because it may be easily cut out to ensure easy contact and gives excellent elasticity without being crushed by lateral pressure.

Abstract: A method of designing an integrated circuit including executing a placement algorithm to place a set of objects within the integrated circuit. The set of objects includes latched objects and non-latched objects. The algorithm places objects to minimize clock signal delay subject to a constraint on the placement distribution of the latched objects relative to the placement distribution of the non-latched objects. The latched object and non-latched object placement constraints may limit the difference between the latched object center of mass and a non-latched object center of mass. The latched object center of mass equals a sum of size-location products for each latched object divided by the sum of sizes for each latched object. The constraints may require that the latched object center of mass and the non-latched center of mass both equal the center of mass for all objects.

Abstract: Disclosed is an optical cable with a secondary sheath for surrounding and protecting a plurality of optical fiber units in which at least 1-core optical fiber is mounted in a buffer tube, wherein the secondary sheath is made of a mixture including 100 parts by weight of base resin selected from the group consisting of low density polyethylene, linear low density polyethylene, and their mixture; and 0.2 to 60 parts by weight of inorganic additive. The secondary sheath of this optical cable shows excellent cutting and tear characteristics and ensures easy contact and divergence.

Abstract: Disclosed are an optical fiber unit in which at least 1-core optical fiber is mounted in and protected by a buffer tube, and an optical cable including the optical fiber unit. The buffer tube is made of a mixture, which includes a composite resin including a resin selected from polyolefin polymer, nitrile rubber and their mixture, and plasticized polyvinylchloride; and an inorganic additive, wherein, in a stress-strain curve of the buffer tube, a modulus is 5 to 50 kgf/mm2 in a linear region with an elongation less than 1% and a tan ? is less than 0.5 at 30° C. The buffer tube of the optical fiber unit may be very usefully applied to an optical cable because it may be easily cut out to ensure easy contact and gives excellent elasticity without being crushed by lateral pressure.

Abstract: A placement technique for designing a layout of an integrated circuit by calculating clustering scores for different pairs of objects in the layout based on connections of two objects in a given pair and the sizes of the two objects, then grouping at least one of the pairs of objects into a cluster based on the clustering scores, partitioning the objects as clustered and ungrouping the cluster after partitioning. The pair of objects having the highest clustering score are grouped into the cluster, and the clustering score is directly proportional to the total weight of connections between the two objects in the respective pair. The clustering scores are preferably inserted in a binary heap to identify the highest clustering score. After grouping, the clustering score for any neighboring object of a clustered object is marked to indicate that the clustering score is invalid and must be recalculated. The calculating and grouping are then repeated iteratively based on the previous clustered layout.

Abstract: A method of designing a layout of an integrated circuit, by grouping a plurality of logic cells in a region of the integrated circuit into at least two separate clusters, placing the clusters in the region of the integrated circuit to optimize total wire length between the clusters (e.g., using quadratic placement), partitioning the region, and recursively repeating the placing and the partitioning to place the logic cells in progressively smaller bins of the region, while ungrouping the clusters. Clustering preferably groups smaller logic cells before grouping larger logic cells, and can be repeated iteratively with further re-grouping of the clusters, prior to the placing and partitioning. The number of iterations can be limited by an operator input parameter. A given cluster is ungrouped when its size is larger than a fraction of total free space available in a corresponding bin. This fraction can also be an operator input parameter.