baber/WOPTO huggingface dataset:
Patent KR-20100026636-A (KR)
Title: Method for preparing metal nanoparticle for low-temperature sintering
Inventor: HEO SOO YEON
IPC: B82B3/00
Filed: 2008-09-01
Abstract: PURPOSE: A manufacturing method of a metal nanoparticle for low temperature sintering is provided to efficiently manufacture a conductive thin film by using the nanoparticles on which melting surfactants are attached. CONSTITUTION: A manufacturing method of a metal nanoparticle for low temperature sintering comprises the following steps: forming an organic ligand-metal complex by mixing metal salt and an amphiphilic first organic ligand precursor in an organic solvent; reducing the organic ligand-metal complex; forming the metal nanopaticles linked by covalent bonds with the organic ligand; and reducing a part or all parts of the first organic ligand into a second organic ligand.
Patent KR-20100027341-A (KR)
Title: Bulletproof panel and method for manufacturing the same
Inventor: LEE HYUCK YUL
IPC: B32B17/10
Filed: 2008-09-02
Abstract: PURPOSE: A bulletproof panel and a manufacturing method thereof are provided to improve the bulletproof effect by employing an adhesive film containing metal wire mesh. CONSTITUTION: A bulletproof panel comprises a base layer(10), reinforcing layers(20), and adhesive films(11). The base layer is formed out of PMMA(Polymethylmethacrylate). The reinforcing layers are laminated on both sides of the base layer. The adhesive films are laminated between the base layer and each reinforcing layer to bond the base and reinforcing layers.
Patent KR-20100030259-A (KR)
Title: 테일게이트의 가니쉬 장착구조
Inventor: CHOI SUG JUNG
IPC: B60J5/00
Filed: 2008-09-10
Abstract: 본 발명은 테일게이트의 닫힘 과정에서 테일게이트 가니쉬에 의해 패널에 충격이 발생하여 테일게이트 외관을 저해하는 것을 방지할 수 있는 테일게이트의 가니쉬 장착구조에 관한 것으로, 본 발명의 테일게이트의 가니쉬 장착구조는, 테일게이트 아웃터 패널(100)에 횡방향으로 취부되는 자동차의 테일게이트 가니쉬의 장착구조에 있어서, 상기 가니쉬의 몸체부(110)는 상기 아웃터 패널(100)과 유격을 갖되 탄성체(120)에 의해 탄성 지지되어 볼트(130) 조립되며, 상기 몸체부(110)의 테두리와 상기 아웃터 패널(100) 사이에 탄성부재(140)가 구비되어,테일게이트의 닫힘 과정에서 가니쉬에 의해 아웃터 패널에 가해지는 충격이 탄성체에 의해 완충이 이루어지므로 테일게이트 닫힘 과정에서 테일게이트 패널에 변형이 발생하는 것을 방지할 수 있는 효과가 있는 발명인 것이다. 
       
     테일게이트, 가니쉬, 아웃터 패널, 변형.
Patent KR-20090032991-A (KR)
Title: Control device, storage device, lsi, and recording compensation method
Inventor: UENO HIROAKI
IPC: G11B5/02
Filed: 2008-09-10
Abstract: A control device, a storage device, an LSI, and a recording compensation method are provided to implement recording compensation with high precision by adding recording polarity in order to correct NTLS dependent on the recording polarity generated in magnetic recording. A control device of a storage device comprises a recording compensation value storage unit which stores recording compensation values corresponding to the polarity of pattern, a pattern detecting unit which detects the polarity of pattern with the pattern in which non-linearity occurs, and a recording compensation unit which performs recording compensation of recorded data by using the recording compensation value corresponding to the polarity of patter when the polarity of pattern detected by the pattern detection unit is stored in the recording compensation value storage unit.
Patent KR-20100030491-A (KR)
Title: Semiconductor chip and semiconductor package using the same
Inventor: LEE SEUNG YEOP
IPC: H01L21/60
Filed: 2008-09-10
Abstract: PURPOSE: A semiconductor chip and a semiconductor package using the same are provided to reduce the whole size of the semiconductor chip by forming a large amount of pads in a limited size of the semiconductor chip. CONSTITUTION: A body part(110) of a semiconductor chip includes circuit parts(111, 113). A first bonding pad(114) is arranged on one side of the body part of the semiconductor chip and connected to the circuit parts. A second bonding pad(116) is insulated from the first bonding pad and is connected to the circuit parts. The second bonding pad covers the one side of the first bonding pad.
Patent KR-20100035346-A (KR)
Title: 카오디오 시스템 및 그에 대한 음량 조절 방법
Inventor: JEONG NAE WOON
IPC: G11B20/10
Filed: 2008-09-26
Abstract: 본 발명은 카오디오 시스템 및 그에 대한 음량 조절 방법에 관한 것으로서, 다수의 스피커를 구비한 카오디오 시스템에 있어서, 사용자의 선택에 따른 모드 전환 신호를 출력하는 키 입력부 및 상기 모드 전환 신호 수신시 기설정된 음량 조절값으로 상기 스피커의 음량을 개별 제어하여 운전자 모드 또는 일반 모드로 전환하도록 제어하는 모드 제어부을 포함하는 카오디오 시스템 및 그에 대한 음량 조절 방법을 제공한다. 
       
     음량조절, 스피커, 운전자 모드, 일반 모드
Patent KR-20100038989-A (KR)
Title: Active rolling walking footware
Inventor: SEO JEOUNG JOO
IPC: A43B7/32
Filed: 2008-10-07
Abstract: PURPOSE: A functional shoe is provided, which naturally accomplishes rolling according to the movement of the centroid. CONSTITUTION: A functional shoe comprises: an outsole(10) having the bottom shape of arc; and a midsole(20) which is adhered to the upper part of the outsole and in which a rolling protrusion(22) is formed in the bottom surface. The rolling protrusion is formed to be slope at the middle part inside the plantar in the direction facing the little toe. In the rear of the rolling protrusion, a ventilation hole and a penetration hole are formed.
Patent KR-20100039980-A (KR)
Title: Gap adjuster between shower head and heater block for semiconductor manufacturing apparatus
Inventor: KIM MIN KYOUNG
IPC: H01L21/205
Filed: 2008-10-09
Abstract: PURPOSE: A gap adjustment unit between the shower head and the heater block of a semiconductor manufacturing apparatus is provided to improve the apparatus management efficiency by measuring an adjustment distance with a gap adjustment gauge. CONSTITUTION: A plurality of gap adjustment rods(110) is installed on a shower head. One end of the gap adjustment rod is connected to the upper side of the shower head. The other end of the gap adjustment rod passes through the upper side of the chamber(10). An adjustment nut(130) adjusts the vertical movement of the gap adjustment rod. A fixing unit(120) prevents the adjustment nut from releasing. A gap measurement gauge(150) measure the vertical movement distance of the gap adjustment rod.
Patent KR-20100044477-A (KR)
Title: Display apparatus and control method thereof
Inventor: SHIN SANG WON
IPC: H04N5/445
Filed: 2008-10-22
Abstract: PURPOSE: A display device and a control method thereof are provided to control features of a caption, thereby transmitting dynamic information to a user and recognizing volume of voice by only a caption when a mute function is set or a user has auditory disability. CONSTITUTION: A display device comprises a voice processor(130), a caption processing unit(150), a display unit(120) and a controller(160). The voice processor processes voice. The caption processing unit processes a caption. The display unit displays a caption processed in the caption processing unit. A controller controls the caption processing unit to adjust a feature of the caption corresponding to volume of the voice.
Patent KR-20100045707-A (KR)
Title: A process for preparing rice puffing confectionery
Inventor: CHUNG SU YEON
IPC: A23G3/52
Filed: 2008-10-24
Abstract: PURPOSE: A manufacturing method of puffed rice snack is provided to improve nutrients of the puffed rice snack by forming a sheet on a molding process after manufacturing a rice cake with different kinds of rice, and to make the snacks having different shapes. CONSTITUTION: A manufacturing method of puffed rice snack includes the following steps: dehydrating rice to moisture content of 20-40wt%; crushing rice by pulverizing the rice with a diameter of 100 ~ 200 m; manufacturing a rice cake by steaming the rice flour with water; forming a sheet by compressing the rice cake; aging the sheet at a low temperature; cutting the sheet to a pea size; aging and drying a cut base; puffing the dried and aged base in a puffing machine.
Patent KR-20100045730-A (KR)
Title: Wire-rod coil cooling apparatus
Inventor: HWANG JOONG KI
IPC: B21B45/02
Filed: 2008-10-24
Abstract: PURPOSE: A wire rod coil cooling apparatus is provided to produce a wire rod coil of high quality through partial cooling control of the wire rod coil. CONSTITUTION: A wire rod coil cooling apparatus(1) comprises a transfer unit(10) installed on the top of a transfer mechanism(100') for a wire rod coil, and an air cooling unit(30) which is installed to ascend and descend on the transfer unit and blows air for uniform cooling of a wire rod coil. The transfer unit comprises a rail member(12) installed on the top of a transfer chain conveyor(120) to form an endless track, a transfer frame, and a vertical driving cylinder(16).
Patent KR-20100048198-A (KR)
Title: Resistance changeable memory device and method of forming thereof
Inventor: OH GYU HWAN
IPC: H01L21/8247
Filed: 2008-10-30
Abstract: PURPOSE: A resistance variable memory device and a method for forming the same are provided to selectively reduce the interfacial resistance between a variable resistance pattern and a lower electrode by minimizing the area to which the lower electrode and the variable resistance pattern are contacted. CONSTITUTION: A first interlayer insulation layer(120) is formed on a semiconductor substrate. A lower electrode is formed in the first interlayer insulation layer. The rectangular upper side of the lower electrode is expanded to a first direction. A variable resistance pattern(160) is formed on the lower electrode. A first insulation layer(142) which covers the lower electrode is formed on the first interlayer insulation layer. The first insulation layer is patterned to form a first trench which is expanded to a second direction. A spacer which is expanded to the second direction is formed on the sidewall of the first trench. A second insulation layer(144) is formed in order to fill the first trench.
Patent KR-20090115647-A (KR)
Title: A side frame for refrigerator door
Inventor: SHIN KOOK SOO
IPC: F25D23/02
Filed: 2008-11-05
Abstract: PURPOSE: A lateral frame for a refrigerator door capable of attaching a side frame on a side of a refrigerator door is provided to securely fix a coupling unit on a side frame and quickly disassemble the side frame. CONSTITUTION: A lateral frame for a refrigerator door capable of attaching a side frame on a side of a refrigerator door includes a coupling aperture and a side frame(120). The coupling aperture forms a pair of a refrigerator door main body. The side frame is equipped on a second coupling unit which is coupled on the coupling aperture.
Patent KR-20100052194-A (KR)
Title: Method for supplying semifinished products for forming vehicle tires
Inventor: SHIN JIN UK
IPC: B29D30/08
Filed: 2008-11-10
Abstract: PURPOSE: A method for supplying semi-finished products for molding tires of a vehicle is provided to increase productivity by removing the loss of molding material shortage and the loss of passive transport by developing a new LGV return logic. CONSTITUTION: A method for supplying semi-finished products for molding tires of a vehicle includes: a step(S3) deciding whether the indication of collecting work exists or not after returning material to a molding process part by AGV; a step(S6) which allocates indication to the AGV and sending back to a destination warehouse when deciding that the indication exists; a step(S10) making the AGV stand by in a standby position of a warehouse along the shortest route to a material processing part when the indication does not exists.
Patent KR-20090054377-A (KR)
Title: 교량용 비상대피계단
Inventor: LEE KYU YUN
IPC: E04F11/02
Filed: 2008-11-19
Abstract: 본 발명에 따르면, 교량 슬래브의 일측에서 외부로 수평 연장된 제1 메인 계단참; 상기 제1 메인 계단참의 하부로부터 지면으로 연장되어 지면과 고정된 제1 포스트; 상기 제1 메인 계단참으로부터 경사지게 하방으로 연장되며 상부에 계단이 형성된 제1 계단부; 상기 제1 계단부의 연장된 단부에서 수평 연장된 제1 서브 계단참; 상기 제1 서브 계단참으로부터 경사지게 하방으로 연장되며 상부에 계단이 형성된 제2 계단부; 상기 제2 계단부의 연장된 단부에서 수평 연장되되, 상기 제1 메인 계단참의 폭보다 넓은 폭을 가진 제2 메인 계단참; 상기 제2 메인 계단참의 하부로부터 지면으로 연장되어 지면과 고정된 제2 포스트; 상기 제2 메인 계단참으로부터 상기 제1 계단부의 경사 방향과 반대방향으로 경사지게 하방으로 연장되며 상부에 계단이 형성된 제3 계단부; 상기 제3 계단부의 연장된 단부에서 수평 연장된 제2 서브 계단참; 및 상기 제2 서브 계단참으로부터 경사지게 하방으로 연장되며 상부에 계단이 형성된 제4 계단부를 포함하는 교량용 비상대피계단이 제공된다. 본 발명에 따르면, 교량에서 열차의 사고 등 비상시에 대피가 가능하고, 또한 교량의 유지보수를 위한 통로로 사용될 수 있다. 
       
     교량, 비상대피계단, 계단참
Patent KR-20100057270-A (KR)
Title: Rubbing cloth auto testing equipment
Inventor: LEE JONG BOK
IPC: G02F1/1337
Filed: 2008-11-21
Abstract: PURPOSE: A device for automatically inspecting a rubbing cloth is provided to automatically perform a series of processes for removing a cloth strand. CONSTITUTION: A rubbing roll transferring unit(4) clamps a rubbing roll from a rubbing roll supply unit. The rubbing roll transferring unit transfers the rubbing roll to a rubbing cloth aging unit to age a rubbing cloth. The rubbing roll transferring unit supplies the aged rubbing roll to a unit for removing a defective rubbing cloth. The rubbing roll transferring unit receives the rubbing roll without the defective rubbing cloth again. The rubbing roll transferring unit unclamps the rubbing roll to the rubbing roll supply unit.
Patent KR-20100061907-A (KR)
Title: Portable terminal including slide module
Inventor: MIN JI YONG
IPC: H04B1/38
Filed: 2008-12-01
Abstract: PURPOSE: A portable terminal equipped with a slide module is provided to form the slide module into one body with the first body or the second body. CONSTITUTION: The first body(10') and the second body(20') are relatively moved each other and are opened/closed. A slide module(33') includes a hinge plate and a hinge spring. In order to guide the first body opened/closed about the second body, the hinge plate is fixed to the second body. The hinge plate is inserted movably in the first body. The hinge spring elasticity-biases the first body to an opened/closed direction.
Patent KR-20090071381-A (KR)
Title: Mountable integrated circuit package system with stacking interposer
Inventor: YOON IN SANG
IPC: H01L23/12
Filed: 2008-12-04
Abstract: A mountable integrated circuit package system equipped with the laminate interposer is provided to improve yield and reliability of the mountable integrated circuit package system by improving the mechanical supporting and rigidity. An inter-integrated circuit apparatus(208) is mounted on a carrier(206) by the first adhesive part(210). The inter-integrated circuit apparatus is the excellence package. The first substrate(212) is mounted on the inter-integrated circuit apparatus by the second adhesive part(213). The first inside interconnection unit(214) electrically connects the first substrate to the carrier. A package encapsulant(216) having a collaboration(218) covers the carrier, the inter-integrated circuit apparatus, and the first inside interconnection unit.
Patent KR-20100065560-A (KR)
Title: System for electronic article surveillance based on radio frequency identification
Inventor: LEE CHANG YEOL
IPC: G08B15/00
Filed: 2008-12-08
Abstract: PURPOSE: An EAS(Electronic Article Surveillance) system based on RFID(Radio Frequency Identification) for using an RFID technology as the EAS substitution use of the RFID is provided to reduce the size of a system configuration by implementing two functions of an RFID device and an EAS device. CONSTITUTION: An EAS/RFID tag(100) stores an EAS value in the reserved space. The EAS/RFID tag offers a serial code to an RFID reader. A sales manager(200) recognizes the EAS value through the RFID reader. The sale management part varies the acknowledged EAS value into the sell completion value. A robbery preventing unit decides whether the object is sold based on the acknowledged EAS.
Patent KR-20080113337-A (KR)
Title: 적외선 카메라가 결합된 광파 측정기기를 이용한 터널 안전관리 시스템 및 그 제어방법
Inventor: KIM JUNG BUM
IPC: G01B11/16
Filed: 2008-12-09
Abstract: 본 발명은 터널의 내공변위를 측정함과 동시에 터널의 내부 사항을 실시간으로 영상으로 감지할 수 있는 터널 통합 안전관리 시스템에 관한 것으로, 특히 터널의 내공변위를 측정하는 광파 측정기기를 보호할 수 있는 보호수단이 구비되고, 상기 광파 측정기기의 하단부에 X축과 Y축으로 360° 회전가능한 무인카메라와 열영상카메라가 부착되어, 터널의 내부사항을 실시간으로 파악할 수 있으므로 인해 터널 내부의 사고, 소통상태를 확인할 수 있는 것을 특징으로 하는 적외선 카메라가 결합된 광파 측정기기를 이용한 터널 안전관리 시스템 및 그 제어방법에 관한 것으로서, 그 구성은 터널의 일측에 부착되는 고정 받침대와, 상기 고정 받침대의 내부에 구비되는 제어수단과, 상기 고정 받침대의 상부에 구비되며, 광파 측정기기를 보호하기 위한 보호수단과, 상기 보호수단의 내측에 구비되는 광파 측정기기와, 상기 고정 받침대의 하부에 구비되는 회전판과, 상기 회전판의 일측에 구비되는 무인카메라 및 상기 회전판의 타측에 구비되는 열영상 카메라를 포함하여 구성된 것을 특징으로 하는 적외선 카메라가 결합된 광파 측정기기를 이용한 터널 안전관리 시스템 및 그 제어방법에 관한 것이다. 
     상기와 같이 구성된 적외선 카메라가 결합된 광파 측정기기를 이용한 터널 안전관리 시스템 및 그 제어방법에 의하면, 상기 광파 측정기기를 사용하지 않은 경우에는, 상기 광파 측정기기를 외부의 먼지나 이물질로부터 보호할 수 있어 그 내구성을 확보할 수 있고, 뿐만 아니라 그로 인한 계측 오차를 방지할 수 있는 효 과가 있으며, 또한 상기 광파 측정기기의 보호수단인 개폐문을 자동으로 열고 닫을 수 있어서, 상기 광파 측정기기를 터널의 일측에 반영구적으로 고정하여 사용할 수 있으므로 인해 계측 오차를 방지할 수 있어, 계측결과의 신뢰성을 확보할 수 있는 효과가 있고, 또한 광파 측정기기의 하단부에 X축과 Y축으로 360° 회전가능한 무인카메라와 열영상카메라가 부착되어 있어, 터널의 내부사항을 실시간으로 파악할 수 있으므로 인해 터널 내부의 사고, 소통상태를 확인할 수 있는 효과가 있다. 
       
     광파 측정기기, 무인카메라, 열영상카메라
Patent KR-20100068773-A (KR)
Title: Electrode tip apparatus for maintaining for spot welding
Inventor: KIM YONG MI
IPC: B23K11/36
Filed: 2008-12-15
Abstract: PURPOSE: An electrode tip apparatus for maintaining for spot welding is provided to minimize the cost-up according to the replace of the electrode tip. CONSTITUTION: An electrode tip apparatus for maintaining for spot welding comprises a processing tool(130), a post(112), and a desorption member(120). The processing tool is fixed to a drilling machine(140). The processing tool processes an electrode tip. The processing tool comprises a fixing jig and processing jigs. A fixing jig is attached and detached in the drilling machine. The processing jig is combined in the fixing jig. A processing tip is built in the processing jig. The post is formed in the location corresponding to the processing tool. An electrode tip is fixed in the post. A detaching member attaches and detaches an electrode tip.
Patent KR-20100073135-A (KR)
Title: Intrusion detection method and apparatus using application protocol inference
Inventor: YI SUNG WON
IPC: H04L12/22
Filed: 2008-12-22
Abstract: PURPOSE: A network intrusion detection method and apparatus using application protocol inference are provided to prevent the waste of resources and time by creating a protocol model without previous examination for target services. CONSTITUTION: A keyword extracting unit(140) extracts characters as keywords from a packet. A protocol extracting unit extracts a usage case of protocol using the keywords extracted by the keyword extracting unit. A model generating unit(160) creates a protocol model on the basis of stored PTA(Prefix Tree Acceptor). An intrusion detecting unit(170) executes network intrusion detection using the new protocol model.
Patent KR-20100073155-A (KR)
Title: Method and apparatus for managing workload and distributed computing system using the same
Inventor: KIM JIN MEE
IPC: G06F9/50
Filed: 2008-12-22
Abstract: PURPOSE: A method and a device for managing workload and distributed computing system using the same are provided to assign resources as exact necessary amount, thereby preventing waste of resources from the beginning. CONSTITUTION: A policy storage unit(201) stores a system policy. An auto sensing unit(203) examines system information about workload state and resource use of a system. An automation control unit(205) distinguishes virtual node which needs resources through the system policy and the system information. The automation control unit calculates required resource amount. According to the system policy and the resource demand amount of virtual node, an auto provisioning unit(207) determines allocation and times of the resources.
Patent KR-20100073174-A (KR)
Title: Method and apparatus for shape deforming surface based 3d human model
Inventor: LIM SEONG JAE
IPC: G06T17/00
Filed: 2008-12-22
Abstract: PURPOSE: A method and an apparatus for deforming a shape of a human body model are provided to automatically and naturally deform the shape of a human body model by forming the shape of the human body according to the motion capture data. CONSTITUTION: A human body generator(200) reconfigures a Nurbs curved surface model based on a joint skeleton structure, and a statistical transformation information generator(300) generates the statistical deformation information for a control parameter of the Nurbs curved surface model based on a parameter of a joint and key section curve in various specific motions. A human body shape deformation unit(400) deforms the human body model shape according to the statistical deformation information and the Nurbs curved surface model.
Patent KR-20100073216-A (KR)
Title: Fixing apparatus for window
Inventor: JUNG WOON SEOB
IPC: E06B1/36
Filed: 2008-12-23
Abstract: PURPOSE: A device for fixing a composite member of a window is provided to stably fix composite members using insertion pieces even if the materials of the composite members are different. CONSTITUTION: A device for fixing a composite member of a window comprises a hanging channel(110) and a connector(120). The hanging channel is formed in the inner side surface of an outer frame(10). A hanging slit(112) is formed in the hanging channel in a longitudinal direction. The connector comprises a main body and an insertion piece. The main body is formed in the outer side surface of an inner frame(20). The insertion piece is formed in the main body in a wedge shape.
Patent KR-20100074490-A (KR)
Title: Apparatus for treating perfluorocompounds
Inventor: JANG SEOK KYENG
IPC: B01D53/02
Filed: 2008-12-24
Abstract: PURPOSE: An apparatus for processing a perfluorinated compound is provided to perfectly process CF4 gas which is produced in an etching process during a manufacturing process of a semiconductor production process into harmless gas. CONSTITUTION: An apparatus for processing a perfluorinated compound includes the following: a heat treatment portion(100) treating CF4 gas into harmless gas; a filter processing portion preventing recombination of the CF4 gas at a room temperature; and an absorbent treatment portion(300) processing HF gas which is produced after reaction of CF4 gas. The heat treatment portion includes a combustion chamber portion(110), a circulation tank(120), and a scrubbing treatment portion(130).
Patent KR-20100076378-A (KR)
Title: Method for remove a by-product of semiconductor manufacturing device
Inventor: KIM YEONG SIL
IPC: H01L21/3065
Filed: 2008-12-26
Abstract: PURPOSE: A method for removing by-products of semiconductor manufacturing facilities is provided to prevent metal short and improve the yield of a wafer by removing by-products which can be attached to the wafer. CONSTITUTION: An etching process is performed by lifting a cathode through a bellows hose(100). The cathode descends so that a wafer is the unloaded(110). The cathode is elevated before loading the wafer so that the by-products attached to the bellows pipe are removed(120). The by-products removed from the bellows pipe are discharged through a vacuum line(122). The wafer is loaded in the cathode(130).
Patent KR-20100077673-A (KR)
Title: Novel compound for organic photoelectric device and organic photoelectric device including the same
Inventor: KIM HYUNG SUN
IPC: C09K11/06
Filed: 2008-12-29
Abstract: PURPOSE: A novel compound for an organic photoelectric device is provided to easily form an organic thin film layer through a wet process due to high solubility to an organic solvent and to obtain very excellent efficiency by occurring phosphorescence in a wide wavelength range from red to blue. CONSTITUTION: A novel compound for an organic device is marked as a chemical formula 1. In the chemical formula 1, Ar1 is hydrogen or a fluorine group with C18-C40 and L1 is an alkylene group with C1-C30, an arylene group with C6-C30, a heteroarylene with C1-C30, and nitrogen. In the chemical formula X1-X3 are selected from a group comprising N, NR'_1, O, S, CR'_2, and CR'_3R'_4 and a is integer of 1-4.