Abstract: A base station system according to an aspect of the invention includes a baseband unit (BBU) and a radio frequency (RF) unit (RFU) connected to the BBU via a communication line. The RFU (BBU) measures the frequencies of occurrence of sampled values indicated by sampled data that is a digital signal corresponding to a baseband signal to be transmitted to the BBU (RFU), and generates a frequency distribution representing a relationship between the sampled value having occurred and the frequency of occurrence. Furthermore, the RFU (BBU) determines a plurality of thresholds for compressing the sampled data, which are used for quantization processing of the sampled value, in accordance with the generated frequency distribution, and compresses the sampled data by the quantization processing using the plurality of thresholds.

Abstract: A base station system according to an aspect of the invention includes a baseband unit (BBU) and a radio frequency (RF) unit (RFU) connected to the BBU via a communication line. The RFU (BBU) measures the frequencies of occurrence of sampled values indicated by sampled data that is a digital signal corresponding to a baseband signal to be transmitted to the BBU (RFU), and generates a frequency distribution representing a relationship between the sampled value having occurred and the frequency of occurrence. Furthermore, the RFU (BBU) determines a plurality of thresholds for compressing the sampled data, which are used for quantization processing of the sampled value, in accordance with the generated frequency distribution, and compresses the sampled data by the quantization processing using the plurality of thresholds.

Abstract: A base station system according to an aspect of the invention includes a baseband unit (BBU) and a radio frequency (RF) unit (RFU) connected to the BBU via a communication line. The RFU (BBU) measures the frequencies of occurrence of sampled values indicated by sampled data that is a digital signal corresponding to a baseband signal to be transmitted to the BBU (RFU), and generates a frequency distribution representing a relationship between the sampled value having occurred and the frequency of occurrence. Furthermore, the RFU (BBU) determines a plurality of thresholds for compressing the sampled data, which are used for quantization processing of the sampled value, in accordance with the generated frequency distribution, and compresses the sampled data by the quantization processing using the plurality of thresholds.

Abstract: A base station system according to an aspect of the invention includes a baseband unit (BBU) and a radio frequency (RF) unit (RFU) connected to the BBU via a communication line. The RFU (BBU) measures the frequencies of occurrence of sampled values indicated by sampled data that is a digital signal corresponding to a baseband signal to be transmitted to the BBU (RFU), and generates a frequency distribution representing a relationship between the sampled value having occurred and the frequency of occurrence. Furthermore, the RFU (BBU) determines a plurality of thresholds for compressing the sampled data, which are used for quantization processing of the sampled value, in accordance with the generated frequency distribution, and compresses the sampled data by the quantization processing using the plurality of thresholds.

Abstract: A photocatalyst produced from an easily available, relatively low-cost silicon oxide material is disclosed which is capable of decomposing environmental pollutants with improved efficiency. The photocatalyst is produced by pulverizing an artificial crystal, specifically machining waste thereof, into powder particles having a particle diameter of not more than 3.0 mm and then immersing the particles into a solution containing a hydrogen fluoride for activation. Environmental pollutants such as nitrogen oxides (NOx) and harmful organic compounds can be efficiently decomposed by coming into contact with this photocatalyst while being irradiated with activation light under oxidizing conditions.

Abstract: A photocatalyst produced from an easily available, relatively low-cost silicon oxide material is disclosed which is capable of decomposing environmental pollutants with improved efficiency. The photocatalyst is produced by pulverizing an artificial crystal, specifically machining waste thereof, into powder particles having a particle diameter of not more than 3.0 mm and then immersing the particles into a solution containing a hydrogen fluoride for activation. Environmental pollutants such as nitrogen oxides (NOx) and harmful organic compounds can be efficiently decomposed by coming into contact with this photocatalyst while being irradiated with activation light under oxidizing conditions.

Abstract: To improve transmission characteristics of a CS-RZ signal, a laser diode (LD) (12) outputs a continuous light (CW light) having a wavelength &lgr;s (frequency f0). A CS-RZ pulse train shaper (14) generates a CS-RZ optical pulse train at a bit rate (B) from the CW output light from the LD (12). A data modulator (16) intensity-modulates an output optical pulse train from the shaper (14) according to a data (D) to be transmitted. An optical bandpass filter (18) passes through all of a component of carrier frequency (f0) and a component of frequency f1 (=f0+B/2) and transmits a small amount of component of frequency f2 (=f0−B/2).

Abstract: The present invention relates to an epoxy resin composition for FRP that will be used for fishing rods, golf club shafts, and the like, a prepreg that is an intermediate material made up of an epoxy resin composition combined with reinforcing fibers, and a tubular molded article obtained using it. The epoxy resin composition for FRP of the present invention comprises (A) a bisphenol A-type epoxy resin, (B) an epoxy resin having oxazolidone rings, and (C) a curing agent. By using the epoxy resin composition for FRP of the present invention, a prepreg quite excellent in handleability and a tubular molded article improved in flexural strength in the longitudinal direction and crushing strength in the diametrical direction can be obtained.

Abstract: A novel unidirectionally paralleled fiber reinforced thermosetting resin prepreg excellent in moldability which has plural grooves arranged continuously in longitudinal direction on at least one side surface thereof.

Abstract: An epoxy resin composition characterized by comprising, as essential components,(A) a bifunctional epoxy resin,(B) a trifunctional epoxy resin,(C) a phenol compound represented by the following formula ##STR1## (X.sub.1 to X.sub.8 each represent Br, Cl or H and at least four of X.sub.1 to X.sub.8 each represent Br or Cl; R.sub.1 and R.sub.2 each represent H or CH.sub.3), and(D) 4,4'-diaminodiphenyl sulfone or 3,3'-diaminodiphenyl sulfone.

Abstract: An intermediate for a composite material is described, comprising a reinforcing material impregnated with a resin composition which comprises: (A) 100 parts by weight of a mixture of (I) a polyfunctional maleimide and (II) a polyfunctional cyanate or an oligomer thereof, or a preliminary reaction product of (I) and (II); (B) from 5 to 100 parts by weight of an epoxy compound; and (C) from 5 to 50 parts by weight of a polyester compound.

Abstract: An epoxy resin composition is disclosed, which comprises the following elements:(A) a bifunctional epoxy resin;(B) a trifunctional epoxy resin;(C) a phenolic compound represented by the following general formula: ##STR1## wherein X.sub.1, X.sub.2, X.sub.3, X.sub.4, X.sub.5, X.sub.6, X.sub.7, X.sub.8, X.sub.9, X.sub.10, X.sub.11, X.sub.12, R.sub.1, R.sub.2, R.sub.3 and R.sub.4, which may be the same or different, each represents a hydrogen atom or a methyl group; and(D) 4,4'-diaminodiphenyl sulfone or 3,3'-diaminodiphenyl sulfone, wherein the molar ratio of epoxy groups in element (A) to those in element (B) is in the range of from 1/4.0 to 1/0.1, element (C) is used in an amount that satisfies the condition:1/0.9.ltoreq.(A+B)/C.ltoreq.1/0.1and element (D) is used in an amount that satisfies the condition:1/1.3.ltoreq.(A+B-C)/D.ltoreq.1/0.

Abstract: Oxidizing treatment of carbon fibers under specific conditions provides carbon fibers having oxygen concentration (O.sub.1S /C.sub.1S atom number ratio) in the surface part of the carbon fibers of 0.05 to 0.30 as measured by X-ray photoelectron spectroscopy, coefficients of water-extractable fraction of up to 2.0, and coefficients of tow spread of at least 1.times.10.sup.-3. These carbon fibers are excellent in adhesion to various matrix resins and when mixed as reinforcements with matrix resins, provide composite materials superior especially in impact resistance. The thus obtained composite materials are useful for aircraft, automobiles, and general industrial materials.

Abstract: An intermediate for a composite material is disclosed. The intermediate is obtained by impregnating an epoxy resin composition containing a specific additive into a carbon fiber. The composite material obtained from the intermediate has improved mechanical properties.

Abstract: An intermediate for a composite material is disclosed. The intermediate is obtained by impregnating an epoxy resin composition containing a specific additive into a carbon fiber. The composite material obtained from the intermediate has improved mechanical properties.