NEC

About: NEC is a company organization based out in Tokyo, Japan. It is known for research contribution in the topics: Signal & Layer (electronics). The organization has 33269 authors who have published 57670 publications receiving 835952 citations. The organization is also known as: NEC Corporation & NEC Electronics Corporation.

Cooling system for electronic equipment

Abstract: A cooling system for maintaining the temperature within electronic equipment has a circulation system for pumping a cooling liquid, such as water, through the electronic equipment where it picks up heat generated by the electronic equipment. The cooling liquid is pumped through a plurality of heat exchangers using a refrigerant which is, in turn, pumped through a compressor-condensor combination, each heat exchanger having approximately the same cooling capacity. A central control selects the number of heat exchangers which are to operate at any given time, on a basis of the differential in the temperature of the water being pumped into and out of the electronic equipment. This maintains a desired and relatively wide range of temperatures. A heating element selectively and controllably heats the cooled water to bring the wide range of temperatures to a selected and fixed temperature.

ATM cell format conversion system

Abstract: An ATM (Asynchronous Transfer Mode) cell format conversion system writes in a memory a plurality of ATM cells each being 53 octets long and mapped in the payload fields of virtual containers VC-4-NC which have been multiplexed in the form of STM-N frames and have been extracted from said frames. A 1 octet-long cell overhead is added to each of the ATM cells read out of the memory in response to base frame pulses which are synchronous with the STM-N frames, whereby the ATM cells are converted to 1-octet-added ATM cells each being 54 octets long. The 1-octet-added ATM cells and an idle cell are mapped in an imaginary matrix 5 column groups×9 rows frame by frame and then outputted. This allows each of the STM-N frames or be switched to otherwise processed on an ATM cell basis.

Semiconductor integrated circuit device

Abstract: Wiring is routed to assure insulation between wiring traces in a semiconductor integrated circuit device. The device includes a first wiring trace to which a prescribed voltage is supplied; a second wiring trace that takes on a voltage that exceeds the prescribed voltage; and a third wiring trace that only takes on a voltage less than the prescribed voltage. Alternatively, the device includes a first wiring trace to which a prescribed voltage is supplied; a second wiring trace that takes on a voltage less than the prescribed voltage; and a third wiring trace that takes on a voltage equal to or greater than the prescribed voltage. The wiring traces are routed at a certain wiring space in such a manner that the first wiring trace is interposed between the second and third wiring traces. The first wiring trace for which the potential difference is known to be small beforehand is routed so as to always be adjacent to the second wiring trace. Accordingly, the third wiring trace for which there is the possibility that the potential difference relative to the second wiring trace will become large is never placed directly adjacent the second wiring trace. As a result of such routing, wiring is implemented in such a manner that the insulation between traces can be sufficiently assured.

A call admission control scheme for ATM networks using a simple quality estimate

Abstract: The authors propose a call admission control scheme based on a method of estimating cell loss quality for individual bursty traffic sources. The estimate is expressed in terms of virtual cell loss probability, which may be defined by two traffic characteristic parameters alone: peak and mean rate. The approach is suitable for the estimation of real cell loss probability in heterogeneous and homogeneous traffic models when burst length is larger than buffer capacity. The concept of virtual cell loss probability is extended to the individual call level so as to be able to estimate the quality of service (QOS) provided to individual calls. A virtual bandwidth method is used to develop a practical call admission control system. Quality is ensured by combining a traffic clustering scheme, with a scheme for assigning individual clusters to subcapacities of a link. Priority levels are presented in terms of the class of QOS required, i.e., deterministic or statistical, and the allocation of virtual bandwidth is discussed in terms of both QOS class and traffic characteristics. >

Active matrix liquid crystal display cell with light blocking capacitor electrode above insulating layer

Abstract: In an active matrix liquid crystal display cell having a switching active element, first and second transparent electrodes between which liquid crystal is filled, and a shading layer for protecting the switching active element and enhancing a contrast of light, an insulating layer is interposed between the shading layer and the first transparent electrode with the shading layer partially laid under the first transparent electrode through the insulating layer.