baber/WOPTO huggingface dataset:
Patent KR-20080028276-A (KR)
Title: Self-positioning system of two-way pseudolite
Inventor: KEE CHANG DON
IPC: G01S5/00
Filed: 2007-08-27
Abstract: A self-positioning system of a two-way pseudolite is provided to rapidly form a navigation environment at a predetermined position at any time by positioning the pseudolite in real time irrespective of movement of the pseudolite. A self-positioning system of a two-way pseudolite comprises at least one two-way pseudolite module(201a,201b), a two-way peudolite carrier, reference stations(202a,202b,202c,202d), and a central processing device(203). The at least two-way pseudolite module receives and transmits a navigation signal. The two-way pseudolite carrier moves the two-way pseudolite. The reference stations receive the navigation signal to transmit the signal. The central processing device receives measured values transmitted from each of the reference stations and the two-way pseudolite and combines the measured values to position the pseudolite.
Patent KR-20080032599-A (KR)
Title: Method of manufacturing dielectric film in capacitor
Inventor: CHOI JAE HYOUNG
IPC: H01L27/108
Filed: 2007-08-30
Abstract: A method for manufacturing a capacitor dielectric film is provided to supply large amount of reaction sources at the initial ALD(Automatic Layer Deposition) cycle by setting up the time for supplying a reaction gas of the initial ALD cycle longer than that of a latter ALD cycle. A lower part electrode(110) is formed on a semiconductor substrate(100). A first layer(121), a crystallization prevention layer(125) and a second layer(128) having the high-k are formed on the lower part electrode, as a capacitor dielectric layer(120). The first and the second layers are formed out of at least one selected from a group consisting of HfO2, ZrO2, TawO5, TiO2 and STO(STxBiyTiOx). The capacitor dielectric layer is formed by an ALD method, so as to be deposited uniformly on the surface of the lower part electrode which is formed three-dimensionally. And the capacitor dielectric is formed in a batch type ALD apparatus in which the plural wafers are processed collectively, so as to improve the throughput.
Patent KR-20090024398-A (KR)
Title: Service valve to protect flowing backward of refrigerants
Inventor: KIM JONG CHUL
IPC: F16K15/00
Filed: 2007-09-04
Abstract: A service valve for preventing refrigerants from flowing backward is provided to enable a user to selectively use the service valve according to a work environment by installing the service valve in either a first flow path or a second flow path wherein the refrigerants flow. A service valve(100) for preventing refrigerants from flowing backward comprises the following units. A flow path(120) is formed inside a body(110) of the service valve. A check valve(130) is integrally formed with the flow path. A fluid is flowed in one direction by the service valve installed in either a first flow path(121) or a second flow path(122). A disc(50) linked with a shaft(84) is positioned in a rear side of the check valve.
Patent KR-20090024842-A (KR)
Title: Pad for preparing touch panel, method of preparing touch panel using the same and touch panel thereby
Inventor: PARK JUN YOUNG
IPC: G06F3/041
Filed: 2007-09-05
Abstract: A pad for manufacturing a touch panel, a touch panel manufacturing method using the same, and the touch panel manufactured thereby are provided to prevent the air bubbles from being generated within the coupling surface of a glue layer by minimizing the step height in case of a capacitance touch panel. An insulator layer (100) is formed with an organic insulator or inorganic insulator. A conductive material coating layer(200) is formed on an upper side of the insulator layer. A metal coating layer(300) is formed on an upper side of the conductive material coating layer. The organic insulator or inorganic insulator of the insulator layer is the transparent material. The conductive material of the conductive material coating layer is the transparent material. The metal of the metal coating layer is copper or aluminium. A pad for manufacturing a touch panel is formed with a contact panel of the touch panel.
Patent KR-20090027530-A (KR)
Title: Light emitting diode package
Inventor: OH KWANG YONG
IPC: H01L33/48
Filed: 2007-09-12
Abstract: An LED package IS provided to improve the lifetime and reliability of LED by applying the moisture and oxygen absorption means to the LED package. The package body(13) has the cavity(15). The LED chip(16) is adopted to the cavity. The absorption means(19) is formed within the cavity. The absorption means absorbs the moisture or the oxygen flowed into the cavity. The sealing cover is formed in the cavity with the absorption means. The partition can be installed between the inner wall and LED chip of cavity. The absorption means can be formed between the inner wall of cavity and the partition.
Patent KR-20080027728-A (KR)
Title: Non-aqueous electrolyte and electrochemical device comprising the same
Inventor: YOON SU JIN
IPC: H01M10/0567
Filed: 2007-09-19
Abstract: A non-aqueous electrolyte is provided to optimize the characteristics of a solid electrolyte interphase layer, and improve high-temperature life characteristics of an electrochemical device. A non-aqueous electrolyte includes a first acrylate compound having one or two acryl groups, a second acrylate compound having at least three acryl groups, an electrolyte salt, and an organic solvent. An electrode has the surface on which a coating layer is partially and wholly formed, wherein the coating layer contains (i) a reduced material of the first acrylate compound having one or two acryl groups and (ii) a reduced material of the second acrylate compound having at least three acryl groups.
Patent KR-20090030768-A (KR)
Title: Infrared signal detection circuit using bolometer and detection method
Inventor: SUNG MAN YOUNG
IPC: G01K7/00
Filed: 2007-09-21
Abstract: An infrared ray signal detection circuit using a bolometer and a detecting method thereof are provided to reduce resistance value of a bolometer to 1/4 by adding an OR-gate to a row decoder of a detection circuit. An infrared ray signal detection circuit using a bolometer comprises: a cell array in which an infrared ray lead out cell is arranged into a matrix type; a row decoder performing decoding in the cell array by using a low signal; one or more OR-gates(410,420,430,440,450) for applying the low signal in one or more cells; one or more integrators which integrates and amplifies the value outputted from the cell array; and a column decoder for decoding the output outputted from the integrator.
Patent KR-20090033992-A (KR)
Title: 탈 부착 가능한 전원코드선 정리기
Inventor: NOH YONG JIN
IPC: H02G11/02
Filed: 2007-10-02
Abstract: 본 발명은 각종 기계제품의 전원코드선의 정리 및 보관을 해주는 것으로 더욱 상세하게는 전원코드선의 중간부분을 접어 전원코드선 정리기에 보관하므로 기계제품 사용 후 선을 집어넣어 보관하는 장치이다. 전원코드선 정리기에 선을 보관하므로 전선의 훼손과 노후를 최소화시키고 기계의 몸체에 직접 말아 보관하여 선이꼬임과 엉키는 것을 방지 할 수 있고 미관상 깔끔함과 전선의 파손을 막아주는 역할을 하며 쉽게 탈 부착을 할 수 있어 어떠한 제품에도 적용 사용 할 수 있는 특징이 있다. 
     
     전원코드선. 탈 부착. 정리. 기계제품
Patent KR-20090036694-A (KR)
Title: Transporting member and substrate transporting apparatus having the same
Inventor: JEE HYEON
IPC: H01L21/67
Filed: 2007-10-10
Abstract: A transporting member and substrate transporting apparatus having the same can perform steadily the transfer process of rotation force between the rotation rod and spin transmitter by forming the combining projection and bonding groove. The shaft(110) is parallelly arranged. Each shaft(111) comprises the rotation roller(111a) and a plurality of support rollers(111b). The rotation roller is inserted into a plurality of support rollers. The first rotation transferring part(120) is installed at the first end of the rotation roller. The first rotation transferring part comprises the first rotational plate and a plurality of first magnets(122a). The rotary motor(130) is connected to a plurality of rotation driving parts(140) by the belt(150). The rotation driving parts are rotated by the rotary motor. The rotation driving parts are parallelly arranged.
Patent KR-20070106667-A (KR)
Title: A structure assembled with tires, for floating break-waters
Inventor: HWANG SUNG TAE
IPC: E02B3/06
Filed: 2007-10-12
Abstract: A floating breakwater utilizing waste tires is provided to reduce cost and to utilize characteristics of tires such as non-corrosiveness, high impact resistance, and toughness. In addition, the floating breakwater reduces the intensity of wave action and the circulation of sea water with space serially formed in vertical and horizontal direction. A floating breakwater built by using waste tires is a columnar structure of tires to be floated upright in the water by arranging tire buoys(A), tires(1), and spacers(B), binding the column with rope utilizing a circular plate(C) and fastening both ends of a stay bar with bolts. The tire buoy is a tire filled with foam(2) to have buoyancy. The spacer provides seats for the tires which are supported by bars having the same length. The circular plate to be fit into the hole of a tire has 4 holes and 4 hooks for rope and one center hole for the stay bar.
Patent KR-20090038583-A (KR)
Title: Cosmetic pack for chin
Inventor: LEE SEUNG HEON
IPC: A45D44/22
Filed: 2007-10-16
Abstract: A jaw exclusive face-pack is provided, which makes the face line streamlined, maintains the wetness of the skin, and improves the elasticity. A jaw exclusive face-pack comprises: a sheet(110) which has a shape of covering the skin of the jaw; and an earring part(120) which is cut in an arch shape in both ends of the sheet. A plurality of earring parts are separated from each other at the constant interval. The receiving part(150) is formed at the area in contact with neck among the circumference of the sheet. One or more cut-out unit(140) is formed in the circumference of the sheet. The depression(130) is formed in the center of the sheet. The functional cosmetic is dipped in the liquid at one side of the sheet.
Patent KR-20090041069-A (KR)
Title: Organic electroluminescence device and method for manufacturing the same
Inventor: JEONG YUN SIK
IPC: H05B33/26
Filed: 2007-10-23
Abstract: An organic electroluminescent device and a manufacturing method thereof are provided to deliver a driving signal to a pixel by securing a smooth contact between an anode/cathode electrode and a wiring. An anode electrode(150), a light emitting layer(170), and a cathode electrode(190) are formed on a substrate(100). At least one among the anode electrode and the cathode electrode includes a conductive layer and an interface material. The interface material is coated on both sides of the conductive layer. A thickness ratio of the conductive layer and the interface material is 5:1 or 10:1. The anode electrode and the cathode electrode are includes the conductive layer and the interface material in a contact surface with a wiring. The conductive layer is made of material selected from groups composed of Ag, Al, Mo, W, Ti, and Cu. The interface material includes an ITO(Indium Tin Oxide) or an IZO(Indium Zinc Oxide).
Patent KR-20090041163-A (KR)
Title: Power saving method for ont and olt in optical access network
Inventor: YOON BIN YEONG
IPC: H04B10/272
Filed: 2007-10-23
Abstract: A method for saving power of an ONT(Optical Network terminal) and an OLT(Optical Line Terminal) in an optical access network is provided to decrease the management cost of a network operator as well as save the power of a subscriber by operating an ONT(Optical Network terminal) and an OLT(Optical Line Terminal) in a software manner without using an additional physical device or machine. An ONT is switched to a power saving mode, and cuts off the power for all functions except a controller which monitors and controls external input(S304). It is judged whether or not a request condition for the switch into an active mode is satisfied at the power saving mode(S305). The ONT transmits a wake-up signal to an OLT(S306), and is switched to an active state. The ONT performs a normal operation.
Patent KR-20090041747-A (KR)
Title: Pipes connecting socket
Inventor: HEU BYUNG UK
IPC: F16L21/06
Filed: 2007-10-24
Abstract: A pipe connecting socket is provided to prevent the secession of a connection pipe by adamantly clamping the connection pipe with a clamping ring. A pipe connecting socket comprises: an containing chamber(11) having a sealing incline and a clamping incline; a socket main body(10) including a protrusion part(14) and a delivering part; a rubber ring(20) located on the sealing incline; a clamping ring(30) located on the clamping incline; and a pressurization part(40) moving an unit of a lower part with the delivering part, pressurizing the rubber ring and clamping ring.
Patent KR-20090043238-A (KR)
Inventor: HWANG SUNG JIN
IPC: F24F13/20
Filed: 2007-10-29
Abstract: 본 발명에 따른 공기조화기는 공기 흡입구가 형성된 본체와; 상기 본체에 승강되게 배치되고 공기 토출구가 형성된 토출구 바디와; 상기 토출구 바디의 내측에 회전 가능하게 위치된 복수개의 좌우 풍향조절부재와; 상기 복수개의 좌우 풍향조절부재를 회전시키는 좌우 회전기구와; 상기 좌우 풍향조절부재의 하부를 지지하는 레그가 복수개 형성되고, 상기 복수개의 레그 사이로 공기가 통과하도록 상기 복수개의 레그 사이에 통로가 형성된 서포터를 포함하여, 좌우 풍향조절부재가 토출구 바디의 내부 깊숙이 위치되면서 그 안내 길이를 길게 할 수 있으므로, 토출 공기를 원거리까지 토출, 확산시킬 수 있고 공기의 원활한 유동이 가능한 이점이 있다. 
       
     공기조화기, 본체, 토출구 바디, 좌우 풍향조절부재, 좌우 회전기구, 레그, 통로, 서포터
Patent KR-20090044108-A (KR)
Inventor: CHOI KYUNG HO
IPC: A61K8/891
Filed: 2007-10-31
Abstract: 본 발명은 분산형 티타늄디옥사이드(TiO 2 ) 및 판상안료로 복합화하고 이소프로필 티타늄 트리아이소스테아레이트로 표면처리한 구상안료를 사용한 케이크형의 화장료 조성물로서, 기존의 무기계 및 유기계 자외선 차단제의 단점인 백탁현상 및 번들거림은 최소화시키고 자외선 차단효과는 극대화시킨 오일 케이크형 화장료 조성물에 관한 것이다. 
     자외선 차단, 무기계 자외선 차단제, 유기계 자외선 차단제, 백탁현상, 번들거림, 구상안료, 케이크형 화장료
Patent KR-20090044310-A (KR)
Inventor: HAN SANG MOO
IPC: F02P19/02
Filed: 2007-10-31
Abstract: 본 발명은 글로우 플러그에 관한 것으로서, 상세하게는 디젤기관에서 연료의 착화가 용이하도록, 연소실을 미리 가열하는 글로우 플러그에 관한 것이다. 특히 본 발명은, 하우징과, 상기 하우징에 삽입되고, 전원이 인가되는 중축과, 상기 하우징과 나사 조립 방식으로 결합되고, 상기 중축으로부터 전원을 인가받아서 발열되는 발열체를 포함하는 글로우 플러그를 제시한다. 
       
     글로우 플러그, 세라믹 글로우 플러그, 중축, 발열체, 나사 조립
Patent KR-20090046259-A (KR)
Inventor: BAEK YUN HAK
IPC: B63J2/12
Filed: 2007-11-05
Abstract: 본 발명은 선박용 온수 공급시스템에 관한 것으로서, 온수가열장치(100)와, 온수가열장치(100)에 순환 연결되며 온수배출부(112)가 마련되는 온수순환라인(110)과, 온수순환라인(110)으로부터 분기된 지점에 설치되며 온수를 순환시키기 위한 온수순환펌프(120)와, 온수순환펌프(120)와 대응되도록 온수순환라인(110) 상에 분기 설치되며 온수순환펌프(120)의 미작동시 온수의 순환 경로가 되는 바이패스라인(130)과, 온수순환라인(110)의 일단부에 연결되어 새로운 냉수를 공급하는 냉수공급라인(140)과, 온수순환펌프(120)의 작동을 제어하는 컨트롤패널(160)을 포함한다. 따라서 본 발명에 의하면 온수의 소비가 없거나 온수의 사용이 소량일 경우에는 순환펌프가 작동되지 않으면서도 온수의 온도를 일정하게 유지하여 항시 온수 사용이 가능하도록 하였으며, 더욱이 온수의 사용량 증가시에도 설정된 시간 동안에만 순환펌프의 작동이 이루어지도록 작동 시간을 제어함으로써, 에너지를 절감하고 인력 및 유지보수 비용을 절감할 수 있어 경제성 향상의 효과를 가진다. 
       
     선박, 온수, 온수가열장치, 온수순환펌프, 에너지, 절감
Patent KR-20090047986-A (KR)
Title: 반도체 메모리 장치의 버퍼 회로
Inventor: SIM SU JEONG
IPC: G11C11/407
Filed: 2007-11-09
Abstract: 개시된 본 발명은 반도체 메모리 장치의 버퍼 회로로서, 	입력 신호를 버퍼링하여 버퍼링된 신호를 출력 노드로 출력하는 제 1 버퍼부, 및 상기 입력 신호를 버퍼링하여 버퍼링된 신호를 상기 출력 노드로 출력하는 제 2 버퍼부를 포함하고,상기 제 1 버퍼부 및 상기 제 2 버퍼부는 인에이블 신호에 응답하여 선택적으로 활성화되는 것을 특징으로 한다. 
       
     버퍼,
Patent KR-20080042758-A (KR)
Title: Self-rolling laminated sheet and self-rolling pressure-sensitive adhesive sheet
Inventor: KIUCHI KAZUYUKI
IPC: C09J7/29
Filed: 2007-11-09
Abstract: A self-rolling laminated sheet and a self-rolling pressure-sensitive adhesive sheet are provided to be easily removable from an adherend without causing damage or contamination of the adherend even when the sheet is adhered to the adherend having relatively low strength. A self-rolling laminated sheet includes: a shrinkable film layer(1) which is contractable to at least one axial direction; and a restriction layer(2) which is disposed on the surface of the shrinkable film layer and limits contraction of the shrinkable film layer. When the self-rolling laminated sheet is stimulated to induce contraction of the shrinkable film layer, the self-rolling laminated sheet is rolled from one end thereof toward one direction to form one tube type roll, or is rolled from two opposite ends thereof toward the middle of the two opposite ends to form two tube type rolls.
Patent KR-20080045624-A (KR)
Title: Filter connector with high frequency shield
Inventor: MAHAFFY NEIL ALLAN
IPC: H01R13/719
Filed: 2007-11-16
Abstract: A filtered connector with a high frequency shield is provided to block transmission of a high frequency part of an EMI(Electromagnetic Interference) causing noise via a gap. The first circuit board assembly(24) includes a plurality of pin receiving holes(28). A plurality of pins(12) are protruded through one of the holes. A plurality of signal traces(60) partially extend to the vicinity of at least one of the holes and are connected with one of the pins protruded through the holes. A ground surface(30) is away from the holes and the signal traces and generates a gap(62) with the signal traces. A plurality of filter components(40) include the first terminal(42) connected with the ground surface and the second terminal(44) connected with one of the signal traces. The second circuit board assembly(70) is positioned to be adjacent to the first circuit board facewise and includes a plurality of holes for receiving a dielectric second board and one of the pins. A plurality of shield traces(72) are placed on the second board and extend from the most region of the gaps.
Patent KR-20090053431-A (KR)
Inventor: SHENAI KHATKHATE DEODATTA VINA
IPC: C07F7/02
Filed: 2007-11-23
Abstract: 전자 공여기-치환된 알케닐 리간드를 함유하는 유기금속 화합물이 제공된다. 이들 화합물은 특히 증기 침착 전구체로서 사용되기에 적합하다. 또한, 그러한 화합물을 사용하여 예컨대 ALD 및 CVD에 의해 박막을 침착하는 방법을 제공한다. 
     유기금속, 화합물
Patent KR-20090054593-A (KR)
Inventor: KIM JEONG SEOL
IPC: G09B9/00
Filed: 2007-11-27
Abstract: 본 발명은 자동차 충격 체험용 트레일러에 관한 것으로, 보다 상세하게는 이동이 가능한 트레일러의 프레임 상부에 설치된 경사레일을 따라 시트가 미끄러지게 장착되어 체험자가 그 시트에 앉은 상태에서 시트가 경사레일을 따라 미끄러져 스토퍼에 걸려 멈추면서 가해지는 충격을 체험할 수 있도록 구성된 자동차 충격 체험용 트레일러에 관한 것이다. 
     본 발명에 따른 자동차 충격 체험용 트레일러는, 소정의 견인차량에 견인되도록 프레임과 바퀴가 구비된 트레일러의 상기 프레임 상부에 전방으로 하향경사지게 설치된 경사레일과, 상기 경사레일을 따라 미끄러지도록 그 경사레일에 설치된 대차와, 안전벨트가 구비되고 상기 대차와 일체로 이동되도록 상기 대차의 상부에 전방을 항하게 고정 설치된 시트와, 상기 대차가 충돌하여 멈추도록 상기 경사레일의 전단부에 구비된 스토퍼와, 상기 경사레일을 미끄러져 상기 스토퍼에 충돌하여 멈춘 대차를 상기 경사레일을 따라 끌어올리기 위한 견인수단이 포함된 것을 특징으로 한다. 
     
     트레일러, 자동차, 안전벨트
Patent KR-20090055130-A (KR)
Title: Method for fabricating semiconductor device
Inventor: KIM SUNG JIN
IPC: H01L21/8247
Filed: 2007-11-28
Abstract: A manufacturing method of a semiconductor device is provided to prevent a charge gain or a charge loss by using a nitride film as an insulation film which covers the gate. A gate stack comprises a floating gate(110), a dielectric film(120), and a control gate, and is formed on a semiconductor substrate(100). A spacer(140b) is formed in both sides of the gate stack. A nitride film(150) is formed on the semiconductor substrate as an interlayer insulation film in order to cover the gate stack and the spacer. The nitride film is flattened. The contact electrode is formed through the nitride film in order to be contacted with the semiconductor substrate. Thickness of the nitride film is 5000~7000Å.
Patent KR-20090056244-A (KR)
Title: A parachute
Inventor: KIM YONG SUN
IPC: B64D17/18
Filed: 2007-11-30
Abstract: A parachute is provided to prevent the shaking of the parachute and the user body against air current so that the user can fall toward the target location in a more stable position. A parachute comprises a main body, a vertical air vent(40), a horizontal air vent(50), and a stick member. The main body comprises a rope(11) the user wears. The vertical air vent controls the size of the path in which the air moves vertically by a rope fastening unit. The horizontal air vent is connected to the vertical air vent and controls the path in which the air moves horizontally by the rope fastening unit. The stick member is connected to the circumference of the main body via elastic members.
Patent KR-20080052456-A (KR)
Title: Bearing of a breaking device tool
Inventor: KAHRA OSSI
IPC: E02F5/16
Filed: 2007-12-05
Abstract: A bearing of a breaking device tool is provided to install a bearing busing in a bearing space easily by making a space between the bearing space and the bearing bushing. A bearing of a breaking device tool comprises a frame(10), a tool(6), and a percussion device. The percussion device has a percussion element with which compression stress pulses may be generated in the tool, and transmits them further to a material to be broken. A method for fitting the breaking device tool with the bearing includes the steps of: arranging around the tool at least one bearing bushing(14) having an outer and inner peripheries; attaching the bearing bushing immovably in an annular bearing space(25) around the tool; fitting the tool with the bearing by the medium of a slide surface on the inner periphery of the bearing bushing to be movable in the axial direction; arranging a clearance fit between the outer diameter of the bearing bushing and the diameter(D1) of the bearing space; inserting the bearing bushing in the axial direction to place thereof in the bearing space without a force effect resulting from the reciprocal dimensioning of the diameters of the bearing bushing and the bearing space; and locking the bearing bushing during the use of the breaking device tool in the axial direction.
Patent KR-20090062455-A (KR)
Title: Metal organic chemical vapor deposition apparatus
Inventor: LEE WON SHIN
IPC: C23C16/455
Filed: 2007-12-13
Abstract: A metal-organic chemical vapor deposition apparatus is provided to prevent the occurrence of heat convection resulting from top and bottom temperature difference inside the chamber. A metal-organic chemical vapor deposition apparatus(100) comprises: a process chamber(110) which an upper lid(111) opened downward and a lower lid(112) opened upward and forms a cavity of fixed size when the top and bottom parts are meshed; a wafer mounting part(120) which has upper and lower susceptors(121,122) which are combined to upper and lower hollow shafts(125,126) equipped on the upper and lower lids and in which one or more wafers are placed in the facing surfaces of the upper and lower susceptors; a heating part(130) which has an upper heater(131) provided between the upper lid and the upper susceptor and a lower heater(132) provided between the lower lid and the lower susceptor and provides radiation to the upper and lower susceptors; a driving unit(140) which rotates around the upper and lower hollow shafts to make the upper and lower susceptors rotate in a specific direction; a gas feed part which has upper and lower gas supply inlets(151,152) connected to the upper and lower hollow shafts and supplies a reaction gas between the facing surfaces of the upper and lower susceptors through a supply nozzle(153) connecting the upper and lower hollow shafts; and a gas exhaust part(160) which is arranged to contact the rim of the upper and lower lids and connected to the internal space of the process chamber in order to discharge the used reaction gas.
Patent KR-20090062942-A (KR)
Title: Method and equipment for protecting multi type air conditioner system
Inventor: KIM KYEUNG JAE
IPC: F24F11/00
Filed: 2007-12-13
Abstract: A method and an apparatus for protecting a multi-air-conditioning system when watthour meter communication error is generated are provided to check a multi-air-conditioning system load and then a direct load and perform a minimum operation when an error in communication between a demand controller and a watthour meter is generated. A WP receiver and an EOI receiver of a demand controller respectively receive a WP signal and an EOI signal from a watthour meter(S200). A demand logic of the demand controller receives the EOI signal and the WP signal from the EOI receiver and the WP receiver and determines whether the signals are received(S201). When any one of the EOI signal and the WP signal is not received, a multi-air-conditioning system load is checked under the control of a multi-air-conditioner power controller and minimum operation control is performed(S202). A direct load is checked under the control of a direct load power controller and minimum operation control is carried out(S203).