baber/WOPTO huggingface dataset:
Patent KR-19990083480-A (KR)
Title: 데이터최적화된코덱
IPC: H04M11/00
Filed: 1999-04-26
Abstract: 음성 신호를 전송하기 위해 필요한 μ-법칙(μ-law) 또는 A-법칙(A-law)이라는 대수(logarithmic) 변환 법칙을 사용하여 아날로그 신호가 PCM 코드로 변환될 때, 양자화 잡음(quantization noise)이 데이터 전송내로 끼어드는데, 이러한 양자화 잡음으로 인하여 최대 데이터 전송 속도가 제한된다.  그러나, PCM 코드 신호가 (음성 신호가 아닌) 데이터를 나타낼 때, 아날로그 데이터 신호를 PCM 코드로 선형으로(linearly) 변환한다면, 그러한 대수의 양자화 잡음은 방지될 수 있을 것이다.  디지털 모뎀 호출이 이루어졌다는 것을 변환 코덱(translating CODEC)에 알리기 위해서, 디지털 모뎀은 2100 Hz의 위상 반전을 가진 응답 톤(answer-tone-with-phase-reversal)(ITU-T 추천(Recommendation) G.165에 설명되어 있음)을 나타내는 코드의 하나 이상의 최하위 비트를 할당하여, 이 관련된 코덱에게 디지털 모뎀 연결이 이루어졌다는 것을 알리는 반복적인 패턴 "P1"을 보낸다.  코덱이 P1 패턴을 탐지하면, 아날로그 데이터 신호를 PCM 코드로 선형으로 변환하게 되는데, 이에 의하여 대수의 양자화 잡음이 끼어드는 것을 감소시킬 수 있다.
Patent KR-19990088064-A (KR)
Title: 반도체기판의건조장치및반도체기판의건조방법
IPC: H01L21/00
Filed: 1999-05-06
Abstract: 건조 능력을 저하시키지 않고, 건조 시간을 단축하며, 건조 처리 능력을 향상시킴과 동시에, 유기물의 사용량을 저감시킴으로써, 자연 환경의 보호에 공헌하고, 잔류 유기물의 저감을 도모한다. 
     50장 정도의 반도체 웨이퍼(3)를 건조시키는, 제어된 IPA 건조 장치를 이용하여, 기화된 IPA를 노즐(13) 및 노즐 구멍(13a)을 통해 반도체 웨이퍼(3)에 분무함으로써 반도체 웨이퍼(3)를 건조시킬 때에, IPA 증기를 수직 하측 방향으로부터 반도체 웨이퍼(3)측을 향해 20°∼ 50°의 각도 θ로 분무하도록 한다.  이 때, IPA의 초기 토출량을 0.8 ∼ 1.5cc/s로 하고, 사용량을 70 ∼ 200cc/배치가 되도록 한다.
Patent KR-20000073342-A (KR)
Inventor: LEE UK HA
IPC: H01L21/8242
Filed: 1999-05-10
Abstract: PURPOSE: A method for manufacturing a semiconductor device is provided to simplify a manufacturing process, by forming a sidewall on a side of a second gate in a peripheral circuit region in the state that the plug formed in a cell region is not covered. CONSTITUTION: A field oxidation layer(45) for defining an active region and a field region of a device is formed on a semiconductor substrate(41) of a first conductivity type having a cell region(C2) and a peripheral circuit region(P2). A gate insulating layer(47) is intervened on the cell region and peripheral circuit region of the semiconductor substrate to form first and second gates(49,51) having a cap layer(53) on the gate insulating layer. Impurity ions of a second conductivity type are injected by using the cap layer as a mask to form first and second impurity regions(55,57) in the cell and peripheral circuit regions, respectively. An etch blocking layer(59) covering sidewalls of the field oxidation layer and first/second gates are formed. A sacrificial layer is formed on the etch blocking layer, and a contact hole exposing the first impurity region is formed. A plug(67) contacting the first impurity region is formed in a contact hole, and the remaining sacrificial layer is eliminated to expose an upper part of the plug and the etch blocking layer. The etch blocking layer is intervened on sides of the first and second gates to form first and second sidewalls while a third sidewall is formed on the exposed surface of the plug. A third impurity region overlapping the second impurity region is formed.
Patent KR-20000073546-A (KR)
Inventor: LEE SEUNG PYO
IPC: H01F41/00
Filed: 1999-05-12
Abstract: PURPOSE: A method of making a neon transformer is provided to need no separate case, in which a secondary coil is wound, by charging and infiltrating a secondary coil winding portion at the same time. CONSTITUTION: In a method of making a neon transformer, after assembling primary and secondary coils, a bobbin, on which the primary and secondary coils are wound, is fixed and then a case is assembled. Infiltrating and charging process to the secondary coil winding portion are simultaneously performed using a first charging material such as a mixed material, which is obtained by mixing a silica and an unsaturated polyethylene resin with a rate of 2.5 to 1. The particle of the silica is a range of 0.5 to 2 millimeters.
Patent KR-19990088267-A (KR)
Title: 리튬화망간옥사이드의제조방법
IPC: C01G45/00
Filed: 1999-05-13
Abstract: 본 발명은 화학 제조된 MnO 2 로부터 고순도 리튬화 망간 옥사이드(Li 1+x Mn 2-y O 4 )를 제공하는 방법에 관한 것이다.   리튬화 망간 옥사이드는 재충전 배터리의 양극 재료로서 사용하기에 특히 효과적인 용도를 지닌다.   본 발명은 리튬 화합물을 화학제조된 망간 디옥사이드와 블렌딩하여 망간 디옥사이드/리튬 화합물 블렌드를 형성하는 방법을 포함한다.   블렌드내 리튬 화합물은 망간 디옥사이드 매 1 몰에 대해 리튬 적어도 약 1 몰이다.   블렌드내 리튬 화합물과 망간 디옥사이드는 이온 교환 반응을 거쳐 리튬 이온이 MnO 2 내 나트륨 및 칼륨 이온을 치환시켜 이온 치환 산물을 형성하는 이온 치환 산물을 제공한다.   이어서, 이온 치환 산물은 가열되거나 하소되어 리튬화 망간 디옥사이드를 제공한다.
Patent KR-19990088482-A (KR)
Title: 리소그래픽패턴형성방법
IPC: G03F7/20
Filed: 1999-05-21
Abstract: 본 발명은 대전된 빔을 형성하고, 0.1 내지 5.0 eV 사이의 에너지 분산을 가지는 대전된 미립자를 분리하며, 상기 범위밖에 놓이는 에너지 분산을 가지는 미립자를 빔으로부터 제거하는 단계로 구성되는 리소그래픽 패턴 형성 방법에 관한 것이다.  이렇게 형성되는 대전된 빔은 5·10 -2 내지 10 -4 rad의 빔 발산값이 얻어질 때까지 1차 포커싱되고, 패턴 스텐실을 가지는 마스크가 포커싱된 대전된 빔으로 조사된다.  거기서 상기 마스크를 통과하는 동안 변조되어지는 대전된 빔은 스케일-다운 마스크 패턴의 스텐실에 대응하는 리소그래픽 패턴을 방사선에 민감한 층위에 형성하기 위해 처리동안 2차 포커싱된다.
Patent KR-20000022638-A (KR)
Inventor: CHOE JAE JUN
IPC: G11B19/20
Filed: 1999-06-03
Abstract: PURPOSE: A micro mirror driver is provided to generate a force regardless of a size of a displacement period and an interval between two conductors although a driving displacement is relatively increased, and to reduce a size and a weight by forming a driver in a body with a mirror. CONSTITUTION: In a micro mirror driver, a mirror body(35) is spaced apart from an upper plane of a substrate(31) so as to rotate in a center of a first direction axil. A sense electrode(33) has the same arrangement and structure as a fix electrode(32), and senses a capacitance variation when a common electrode(34) moves. The sense electrode is fixed at the substrate on which a frame(38) is fixed. A power supplies a potential to the fix electrode so as to generate a potential differential between the common electrode and the fix electrode. A sensor measures a variation of a capacitance at the common electrode and at the sense electrode.
Patent KR-20010008680-A (KR)
Title: Over tape for carrier tape
Inventor: YOO SUN JONG
IPC: C09J9/02
Filed: 1999-07-02
Abstract: PURPOSE: The title over tape capable of easily controlling the thickness, preventing the sticking of chips by static electricity and carrying out taping works even at low temperatures is provided, which remarkably promotes productivity and reduces the cost of production. CONSTITUTION: In an over tape for carrier tape containing a transparent thermoplastic film layer and a sealant layer and wrapping a chip type electronic part loaded in holes for loading a supporter and taped along the one side of the upper surface of the supporter, the sealant layer (12b) is formed on the lower face of a transparent thermoplastic film layer (12a) with a thickness of 5 to 15 micrometer as an ethylenevinylacetate layer and emboss treated by an embossing roller before hardening and an antistatic layer (12c) is formed on the upper face of the transparent thermoplastic film layer (12a) and on the lower face of the sealant layer (12b).
Patent KR-19990073359-A (KR)
Title: 인삼차광막
Filed: 1999-07-05
Abstract: 본 발명은 인삼의 생육에 필수 조건인 해가림발로서 부푸라기실을 이용, 그늘지게하여 하단비닐을 직사광선으로부터 보호하며 장마철 또는 우기로 인한 비피해를 최소화한 것에 관한 것이다.
Patent KR-20010009222-A (KR)
Inventor: LEE YONG HUI
IPC: H01L29/78
Filed: 1999-07-08
Abstract: PURPOSE: A method for fabricating a semiconductor device is provided to prevent hot carrier effect by forming thicker edges of a gate insulation layer near a drain. CONSTITUTION: After a thermal oxide layer is formed on a surface of a semiconductor substrate(30), a photoresist layer is formed thereon and patterned to expose only central portions of the thermal oxide layer. The exposed thermal oxide layer is then etched with some thickness. Therefore, the resultant gate oxide layer(312) has a relatively thinner central portion. Next, after another gate oxide layer(341) is formed on the gate oxide layer(312), a doped polysilicon layer(35), a gate metal layer(36), the first dielectric layer(37), a nitride layer(38) and the second dielectric layer(39) are formed thereon in sequence and patterned to form a gate of polycide structure. Next, a halogen ion buried layer and an LDD ion buried layer are formed in the substrate(30), and a gate sidewall spacer(42) is formed. Thereafter, through an annealing process, a halogen ion diffusion region(410), an LDD region(400) and a high-concentration impurity diffusion region(401) are formed in the substrate(30).
Patent KR-20010009408-A (KR)
Inventor: CHOO JAE IN
IPC: H04N5/655
Filed: 1999-07-09
Abstract: PURPOSE: A fixing device of a video display equipment is provided to fix a metal plate coupled with a desktop base or an arm for hanging on the wall in a back side of the video display equipment to be attached/detached in a one-touch system to fix a bracket, so that a fixing time can be reduced and assembly/disassembly can be easily performed. CONSTITUTION: A body(41) is coupled to a back side of the video display equipment through screws. Support guides(42-1,42-2) are installed on both sides of the body(41) and supports metal plates. Both sides of the metal plates coupled to a desktop base or an arm for hanging on the wall are slided and inserted in the support guides(42-1,42-2). A hasp(43) installed on a lower part of the body(41) prevents the shake of the metal plates when the metal plates are inserted.
Patent KR-19990078642-A (KR)
Title: 박막형 희토류계 수지자석의 제조방법
Filed: 1999-07-21
Abstract: 본 발명은 박막형 희토류계 수직자석의 제조방법에 관한 것으로, 산화철 분말, 희토류계 금속분말 및 액상 합성수지가 함유된 액상 자력물질을 교반기에서 혼합시키는 과정과; 상기 혼합된 액상 자력물질을 도메인 마다의 비율이 일정하도록 믹싱하는 과정과; 상기 믹싱된 액상 자력물질의 자화방향을 정렬시키기 위한 전자석(130) 투과과정과; 상기 액상 자력물질을 롤러를 이용하여 리랩스 페이퍼 (relapse paper,120)에 수회 도포시키는 과정과; 상기 각각의 도포 과정 후 소정 온도에서 숙성하여 경화시키는 과정과; 상기 도포 및 숙성 경화과정을 최종 거친 고상 자력물질을 상기 리랩스 페이퍼(relapse paper,120)로 부터 박리하는 과정; 그리고 상기 박리과정을 마친 박막형의 고상 자력물질에 착자 시키는 과정;을 거쳐 제조되는 박막형 희토류계 수지자석의 제조방법을 기술적 요지로 한다.  따라서 다양한 희토류계 금속분말을 사용함으로써 다양한 자속밀도를 가지는 자석의 제조가 가능하고, 유연성 있는 자석이 제조됨에 의해 다양한 용도로 이용이 가능하다는 잇점이 있다.
Patent KR-20010010989-A (KR)
Inventor: CHUN SEONG GYU
IPC: H04N3/19
Filed: 1999-07-24
Abstract: PURPOSE: A circuit for stabilizing high voltage of a monitor is provided to vary a B+ voltage applied to the first side of a fly back transformer(FBT), according to high voltage detecting voltage for synthesizing a direct current(DC) high-voltage detecting voltage with a high-voltage ripple component of high voltage(HV) output from the FBT, thereby minimizing high-voltage changes in accordance with screen brightness changes of the monitor, to prevent screen distortions. CONSTITUTION: A high-voltage detector(21) connected with a high-voltage output line of a fly back transformer(FBT) detects high voltage, and outputs a high-voltage detecting voltage. A feedback output circuit(30) compares the high-voltage detecting voltage with a reference voltage to perform an amplification, and outputs a predetermined high-voltage feedback voltage. A B+ controller(40) performs a pulse width modulation(PWM) controlling for a B+ voltage applied to the first side of the FBT, according to a high-voltage feedback voltage and an inputted synchronous signal, and varies the B+ voltage, to compensate high voltage. The high-voltage detector(21) detects an anode high voltage(HV) applied to a cathode ray tube(CRT) through the second-sided high voltage(HV) output line of the FBT, and outputs high voltage detecting voltage for synthesizing a direct current(DC) high voltage detecting voltage with high voltage ripple component detecting voltage, which is generated when the high voltage is changed according to screen brightness changes.
Patent KR-20010011712-A (KR)
Inventor: LIM CHAN
IPC: H01L21/8242
Filed: 1999-07-30
Abstract: PURPOSE: A method of manufacturing a capacitor of a semiconductor device is to reduce a leakage current and to improve electrical properties thereof. CONSTITUTION: A method of manufacturing a capacitor comprises the steps of: forming a lower electrode(12,13,14) on a semiconductor substrate(11) having an underlying structure formed thereon; forming the first tantalum oxide layer(15) on the lower electrode, followed by performing a plasma treatment thereon; forming the second tantalum oxide layer(16) on the first tantalum oxide layer and sequentially forming a tantalum oxynitride layer(17) thereon; and forming an upper electrode(18,19) on the tantalum oxynitride layer. The lower electrode is a stack formed of a titanium nitride layer and a tungsten layer.
Patent KR-20010011947-A (KR)
Inventor: YOO BYEONG YEOL
IPC: G09G3/20
Filed: 1999-07-31
Abstract: PURPOSE: A clock jitter reducing device for driving flat panel display is provided to remove the noise contained in a horizontal synchronous signal by the relative comparison of same horizontal synchronous signals and to reduce the rising time and falling time of the horizontal synchronous, thereby minimizing the jitter components contained in a clock signal. CONSTITUTION: The clock jitter reducing device for driving flat panel display comprises two amplifiers(11,12) and a comparator(13). The amplifiers(11,12) execute the inversion and non-inversion amplifications of horizontal synchronous signals(H). The comparator(13) compares the outputs of the amplifiers(11,12) to reduce the rising and falling times of the signals(H). The amplifier(11) supplies the non-inversion amplified signals to a non-inversion input terminal(+) of the comparator. The amplifier(12) supplies the inversion amplified signals to an inversion input terminal(-) of the comparator.
Patent KR-20010016886-A (KR)
Inventor: JANG WAN SIK
IPC: F24H9/20
Filed: 1999-08-05
Abstract: PURPOSE: A method for controlling a boiler is provided to rapidly supply the hot water of the optimum temperature by predicting the reuse time of the hot water and reestablishing the waiting time of the hot water upon reusing the hot water in a state of stopping using the hot water. CONSTITUTION: Upon using hot water, a burner of a boiler is ignited by an ignition plug. Gas from a gas valve is burned in the burner and the hot water is supplied. When the supply of the hot water is not stopped, a microcomputer(10) decides that the hot water supply is not stopped. Combustion is continued and the hot water is continuously supplied. In case that the microcomputer senses the stop of the use of the hot water, the ignition of the burner and the hot water supply are stopped. When the hot water is not reused, a timer counts the hot water waiting time from a hot water stop point. Further, the microcomputer decides that the hot water waiting time exceeds a variable establishment time(Tv). Upon reusing the hot water, the microcomputer decides that the hot water waiting time exceeds ten minutes. With more than ten minutes, the variable establishment time is newly established to ten minutes and the burner is continuously ignited to supply the hot water. If the hot water waiting time exceeds two minutes, the variable establishment time is reestablished to two minutes and the burner is ignited. Under two minutes, the variable establishment time is reestablished to two minutes and the burner is ignited.
Patent KR-20000017258-A (KR)
Inventor: BLOOM MARK S
IPC: E03C1/04
Filed: 1999-08-12
Abstract: PURPOSE: A promptly connected hose assembly is provided to reduce hose connecting working hour, to simplify the structure, to be manufactured economically and to improve the reliability in operation. CONSTITUTION: A hydrant assembly is composed of: a water passage installed on a deck and penetrated into the body; a mouth(10) including a water passage tube connected to the water passage; a T-connector installed on the end of the water passage tube to be glide and including a pair of hose connecting parts; a pair of end body valve assemblies(12, 14) installed on the deck; a pair of connector members including a hollow core body storing the lower part of the end body valve assemblies and a hose connection part extended outward; a first hose connected to one among the hose connection parts of the T-connector at the first end part; and a second hose connected to another hose connection part of the connector members at the second end part.
Patent KR-20010017925-A (KR)
Inventor: KIM YEONG HUN
IPC: G06Q10/08
Filed: 1999-08-16
Abstract: PURPOSE: A method for predicting scale of container terminal of a harbor is provided to supply standard information of basic harbor scale and layout fitted to design condition of various container terminals by prediction of a quay scale according to the quantity of goods transported, a scale of equipment yard and a scale of gate area. CONSTITUTION: An information of quay scale(200) is predicted by computation of quay length classified by scenario of the quantity of goods transported and the number of quay crane based on a predeterminded precondition(100) containing set up of ratio, classified by kind of freight, about the quantity of goods transported. An information of yard scale(400) is predicted by setting ratio of equipment yard per total area after computation of area of required equipment yard based on the precondition(100). A standard prediction of scenarios of the quantity of goods transported and shape, operation hours, process time, the number of lane and condition of the lane of gate is set up. An information of gate scale(300) for carrying in and out comprising the number of input and output lane, an average waiting time for the gate and an average number of waiting trucks and waiting area of the gate is predicted. A design plan(600) of the container terminal is established based on the information(200,300,400). A pattern of ship arrived in a port and leaved from the port and truck carried in and out(500) is predicted.
Patent KR-20010018487-A (KR)
Inventor: KANG JEONG GON
IPC: F24F1/00
Filed: 1999-08-19
Abstract: PURPOSE: A grounding device for an air conditioner is provided to install the air conditioner on ground while performing grounding operation and to prevent a grounding plate from being exposed to outside. CONSTITUTION: Base legs(15) are formed on a base pan(10) forming a lower surface of an air conditioner. The base leg is inserted to insertion units(22) formed on supporters(20) supporting the base legs. Ground plates(30) having elastic bent-up units(33,33') are installed on the supporters. Therefore, the base legs and ground are electrically connected by the ground plates. Moreover, the ground plates are attached to the base legs and the ground by elastic force of the elastic bent-up units.
Patent KR-19990083859-A (KR)
Title: 아동미술 교육매체 및 교육방법
Filed: 1999-08-20
Abstract: 본 발명은 개념화된 사고에서 탈피하여 자유로운 상상력의 표현을 자연스럽게 유도해낼 수 있는 아동미술 교육매체 및 방법에 관한 것이다. 
     본 발명에서는 아동들에게 내재되어 있는 상상력의 표현을 지도하기 위한 주제를 여러 단계로 설정하여 상기 각 주제별로 특정 바탕지를 마련하고, 상기 각 주제별 바탕지의 재질과 색상 및 모양과 크기를 선택적으로 도안하여, 지도할 주제와 지도 받을 아동의 개성을 위주로 의도적인 표현활동을 이끌어내는 그림지도용 매체를 형성한 아동미술 교육매체와; 
     아동들에게 내재되어 있는 상상력의 표현을 지도하기 위한 주제를 여러 단계로 설정하여, 각 주제에 맞는 능동적인 표현활동을 실현할 수 있는 그림지도용 바탕지를 도안하는 과정;  아동들의 개성 및 특성을 파악하여 성격별 유형을 분류하는 과정;  상기 분류된 아동들의 성격별 유형에 따라 상기 바탕지의 색상과 재질 또는 형태와 크기를 선택적으로 부여하여 창조적인 표현활동을 실현하도록 유도해내는 과정을 포함하는 아동미술 교육방법을 제공한다.
Patent KR-20010025863-A (KR)
Inventor: CHOO MI GYEONG
IPC: G02F1/1333
Filed: 1999-09-01
Abstract: PURPOSE: The unique number display structure is provided to improve the degree of recognition of a unique number by allowing a unique number shape on a unique number character pad to be exposed intact. CONSTITUTION: The unique number display structure includes insulating substrate(500). A unique number character pad(51) on which a unique number shape(52) is displayed is formed on the substrate(500). The first and second insulating films(58,59) are formed to expose the unique number shape(52) of the unique number character pad(51). At this time, the first insulating film(58) and the second insulating film(59) are formed by a given distance with the unique number character pad(51) in order to entirely expose the unique number character pad(51). Also, the first insulating film(58) is a gate insulating film and the second insulating film(59) is a protection film.
Patent KR-20010026922-A (KR)
Inventor: BAE IN HO
IPC: G06F13/38
Filed: 1999-09-09
Abstract: PURPOSE: The endpoint controller of the USB(Universal Serial Bus) device is provided to enable a user to configure the FIFO(First In First Out) memory area and size that is allocated to each endpoint. CONSTITUTION: The endpoint controller(40_i) of the USB(Universal Serial Bus) device comprises a start address register(42), an end address register(44), a size register(46), and a control circuit(48). The registers(42,44,46) have the data that the user configures. The control circuit calculates the page of the FIFO memory according to the configured value of the registers. The control circuit manages the area of the FIFO memory with the round queue, and generates the overflow or the underflow signal.
Patent KR-20010028286-A (KR)
Inventor: CHOI JIN HO
IPC: B01J35/02
Filed: 1999-09-20
Abstract: PURPOSE: Disclosed are an anatase type titanium dioxide (TiO2) photocatalyst having nano size particle and a preparation method thereof. CONSTITUTION: The titanium dioxide photocatalyst is prepared by the several steps: an addition step of titanium precursor into solution, an addition of acidic or basic catalyst, a peptization step with heat treatment to prepare anatase type titanium dioxide sol solution and a coating step of the previous titanium dioxide on the support. The titanium precursor may be used one compounds of titanium (IV) isopropoxide, titanium (IV) ethoxide, TiCl4 or TiOSO4. The operating condition of peptization step is 4 - 10 h of reaction time and 80±10 deg. C of reaction temperature to prepare nano size amorphous titanium dioxide. The used support is glass, aluminium, iron plate, ceramic plate or various polymers. In addition, an additive may be applied one of inorganic binder such as SiO2 or Al2O3, organic binder of acetic acid or fatty acid, or a hybrid binder.
Patent KR-20010036064-A (KR)
Inventor: JUNG SEOK JIN
IPC: H04L7/00
Filed: 1999-10-05
Abstract: PURPOSE: A device for detecting frequency and timing error in a communication system is provided to reduce the complexity in the structure of a circuit by composing a frequency error detector and a timing error detector as a circuit. CONSTITUTION: A device for detecting frequency and timing error in a communication system includes the first and second band pass filters(401,402), the third and fourth filters(403,404), the first, second, third and fourth multipliers(405,406,407,408) and the first and second adders(409,410). The first band pass filter(401) passes the appointed band about the component of the real number of the input signal. The second band pass filter(402) passes the appointed band about the component of the imaginary number of the input signal. The third filter(403) filters the output signal of the first band pass filter(401). The fourth filter(404) filters the output signal of the second band pass filter(402). The first multiplier(405) multiplies the output signal of the second band pass filter(402) and the output signal of the third filter(403). The second multiplier(406) multiplies the output signal of the first band pass filter(401) and the output signal of the fourth filter(404). The third multiplier(407) multiplies the output signal of the first band pass filter(401) and the output signal of the third filter(403). The fourth multiplier(408) multiplies the output signal of the second band pass filter(402) and the output signal of the fourth filter(404).