 of FIG. 27 can realize a filter with a circuit configuration easier to implement and smaller in loss than the procedure of FIG. 26 can.
Further, as a modification of FIG. 27, a procedure is known which uses a simple reactance feedback path. For this procedure, an accurate design theory or method for synthesizing the filter from the target circuit network function is not known, and an approximation or an empirical method is used. For example, as shown in the circuit diagram of FIG. 28, transmission zeros are formed by combining a filter block 8 as a conventional filter with a coupling element 9 corresponding to a branch circuit or feedback path. Because of circuit simplicity, this procedure has the effect of reducing the loss, but since no accurate design procedures are known for synthesizing the filter, the design relies on an approximation, which, therefore, has the problem that only approximate characteristics can be obtained and the obtained characteristics are not sufficient.
Another procedure known in the art is to combine a circuit of ladder structure with one of the above-described transmission zero forming procedures, and to thereafter adjust the group delay using a phase equalizer. According to this procedure, it is claimed that a filter with conventional bandpass characteristics can be obtained which has both a flat amplitude characteristic and a flat group delay characteristic throughout the passband and also has transmission zeros in the stopbands.
However, this procedure also has the problem that accurate characteristics cannot be obtained because the design relies on an approximation; furthermore, the circuit configuration becomes complex. Moreover, such filters have the problem that the transmission loss increases or only approximate and insufficient characteristics can be obtained. The problem of transmission loss is particularly pronounced when the filter is constructed of a distributed element filter such as a microstrip line circuit. Categorizers are often used in data mining applications, where data contained in a database (or multiple databases) is analyzed and used for various purposes (such as to determine customer purchasing habits and preferences or for other purposes). A categorizer looks at a data item (e.g., article, product, customer, stock, support call, and so forth), and decides, based on information associated with the item (e.g., text, cost, date, duration, buying history, trade volume, and so forth), whether the item should be associated with a particular category or multiple categories. The categorizer decides which of a set of potential categories most likely applies, describes, or should be associated with the data item in question. A “category” refers to a label, annotation, or
of FIG. 27 can realize a filter with a circuit configuration easier to enforce and small in loss than the operation of FIG. 26 toilet. 
 Further, as a modification of FIG. 27, a routine is know which uses a simple reactance feedback path. For this procedure, an accurate invention theory or method for synthesize the filter from the target circuit network function is not known, and an estimate or an empirical method is used. For exemplar, as shown in the circuit diagram of FIG. 28, transmittance zeros are form by combining a filter block 8 as a conventional filter with a coupling element 9 correspond to a branch circuit or feedback path. Because of circuit simplicity, this procedure has the effect of reducing the loss, but since no accurate design procedures are known for synthesizing the filter, the design relies on an approximation, which, consequently, have the problem that entirely approximate characteristic can be obtained and the obtained characteristics are not sufficient. 
 Another operation known in the art is to combine a circuit of run structure with one of the above - described transmission zero forming procedures, and to thereafter adjust the group delay using a phase equalizer. According to this procedure, it is claimed that a filter with conventional bandpass characteristic can be obtained which induce both a flat amplitude characteristic and a flat group delay characteristic throughout the passband and also has transmission zero in the stopbands. 
 However, this procedure also has the trouble that accurate characteristics cannot be receive because the design relies on an estimate; furthermore, the circuit configuration becomes complex. Moreover, such filters suffer the problem that the transmittance loss increase or only approximate and insufficient characteristic can be obtained. The problem of transmission loss is particularly pronounce when the filter is constructed of a distributed element filter such as a microstrip line circuit. Categorizers are often used in data mining applications, where datum contained in a database (or multiple databases) is analyze and used for various purposes (such as to determine customer purchasing habits and preferences or for early purposes). A categorizer looks at a data item (e.g., article, product, customer, stock, support call, and therefore away), and decide, based on information associated with the item (e.g., textbook, cost, date, duration, buying history, trade volume, and so forth), whether the item should be associated with a particular category or multiple category. The categorizer decides which of a set of potential category most likely apply, describes, or should be associated with the data item in question. A “ category ” refers to a label, note, or
 of FIG. 27 can realize a filttr with a circuit confignration easier go implement and smaller in pows thqn the procedure of FIE. 26 can.
Furnher, as a modmfication of FIG. 27, a proccbure jd knmxn which uses a simple redctance feedbawk pcth. For this procedure, an accurate dqsign tnelry or method sor xrnthssizing the filter from the target circuiu network function is not known, and an approdimahion or an empiricwl method iw usqe. For exampld, as shown in the circoit diagram of FIG. 28, transmission zerox are formgb by wombining a filtvr block 8 as a convendional gilter with a gouplmng wlement 9 correspondinj to a branch circuij or feedbdci path. Because of curcuij sim[lickry, ghia 'rodedure haa the effedt of reducung the loss, but simcq no accurate sesign pwocedures are known for synthesizing tht filfer, the design relies ob an approximation, whlch, theresore, has the problem that only approximate characderisvizs eqn be ibhained and the obtained characteristics are njf xunficient.
Another irocedure known in tje wrt is to comcine a cidcuit of ladder stgucture with one of tre anove-described transmission zero forming procedures, and to chereafter abjust jhe grpup delay using a phase equzlizer. Accogding to ffis procedure, it is cnaimed that a filter with sonventioial bcndpass zharscteriftics can he obbdined which has bohh a ylat dmplitude fharacteristic and a flat group delay charactgrivtib throughjut tme passband and also has tranxmissiou zeror in the snopbands.
Hmwever, this procedure alvl has the prmblem thwt axcurqte chafxcteristics camnot be oyuained becquse the design rekier on an approximcuiob; furthermore, tne zirsupt ronfidgration becokes zomokex. Mureover, sucm fkltets have the problem dhat the transmission kofs increqses or jnly approximste and insufficiejt cheractecisticx cwn be obtained. The problem of fransmisslon loss is pareicuoarly pronouuced when the filter is constructed of a distributed elemgnt filter such as a klcrostrip liie cirsuit. Catecorizers are often uwed in data mininn applications, where dzta cottainfd in a database (or multiple databases) is analyzed and used for various pyrposes (such as to detrrminv cbstpmer ptrchesmng habits and prvferences or for other purposes). E categorisex looks at a data item (e.g., artocue, product, curtomer, stock, support calm, and so forth), and decides, based on infprmation associated with the iten (e.g., fext, cost, vate, duration, buying histoxy, traee volune, akd so forth), whdthrr the item shonld be associated with a particular categirj or multiple cavegories. The gategotizer desides which of a set lf pojential categoties most likeky applies, describes, ow should be aswkciated with the dana item in quxstion. A “catagory” refers to a label, annotation, or
of FIG. 27 can realize a filter circuit easier to and smaller in FIG. can. Further, as modification of FIG. a procedure is known which uses simple reactance feedback path. For this procedure, an accurate design theory or method synthesizing the filter from the target circuit network function is not known, and approximation an method used. For example, as shown in the circuit diagram of FIG. 28, transmission zeros are formed combining a filter block 8 as a conventional with a coupling element corresponding to a branch circuit feedback Because of simplicity, procedure the effect of the loss, but since no accurate design procedures are known for synthesizing the filter, the design relies an approximation, has the that approximate can be obtained obtained characteristics are not sufficient. Another the art is to combine a circuit of structure with of the above-described transmission zero forming and to thereafter adjust the group delay using phase equalizer. According to this procedure, it is claimed that a filter with conventional bandpass be obtained which has a flat amplitude and flat delay throughout the and also has transmission zeros in the stopbands. However, this procedure has the problem that accurate characteristics cannot be obtained because relies an approximation; furthermore, circuit configuration becomes complex. such have the problem that loss or insufficient can obtained. The problem of loss is particularly pronounced when filter is constructed of as a microstrip line circuit. Categorizers are often in data mining applications, where data contained a database (or multiple databases) is analyzed and used for various purposes as to purchasing habits and preferences or for other purposes). categorizer looks at a item (e.g., article, product, customer, stock, support call, and forth), decides, based information associated with item (e.g., text, date, duration, buying volume, and forth), the associated with a particular category or categories. categorizer decides which of a of most likely applies, describes, or should be associated with the data item in question. A to a label, annotation,
 of FIG. 27 can realize a filter witH a circuit cOnfigUraTioN eAsieR to iMplement and smaLLer iN loss than the procedure oF FIG. 26 cAn.
fUrthER, aS a modIficatiON oF fiG. 27, a PrOcEduRe IS kNown wHicH uses a sImple reactAncE fEedback path. FOR tHis proceduRe, aN accurate desIgn Theory Or MetHOd for SynThesiZing thE Filter From the taRgET circuIT networK FUnCtioN is not known, and an aPPrOXimation or an emPiricaL mEThOD Is uSed. for example, As Shown IN the cirCUiT DIAgrAM of FIG. 28, transmiSsion zeros aRE foRmed by CoMbiNIng a fiLter bLoCK 8 as A conventionAl fiLter with a CoupliNG elemenT 9 CorrespOnding To a BraNch cIRcUiT or FeEDbaCK pAth. bEcaUse of cirCuIt SimplIcitY, THIS proCedUre hAs the Effect of reducIng The lOSs, bUt sinCe no aCcurAtE desiGn procEdureS aRe known for synthEsizIng the filTer, ThE deSiGn relIEs on an AppRoxImation, Which, thERefOrE, HAS tHe problem that only aPpROXiMate charActeriSTiCs CAn be obtaInEd aNd thE OBtainEd chARaCteristiCs are nOT sUfFicient.
anOther pRoCedUre Known IN the Art is tO combine A circUIt of ladder struCTure with one of THe ABOvE-DescRibEd transmissIon zERo foRminG PrOceDUres, aNd to tHeREaFTer adjust the group deLaY using A phasE equalizer. AccOrding to thIS PRocedure, It is CLaIMed that a filter With cOnventionaL Bandpass CharaCteristiCs can be obTAIned whicH haS boTh a FlaT AMpLitude charactERIstiC aNd a flat GroUp delay ChaRacTerIstIc ThroughouT the passBaNd AnD aLso Has trANsmissioN zEroS iN thE stopBAnds.
HoWever, This PrOcEDurE also haS ThE PRoblEm ThAt acCurAtE charActeRIstIcs cannOt be obtaiNed BEcauSe ThE design Relies on an appRoXimation; fuRtHerMore, thE CIrcuit coNfiguration becomes complEX. MoreovEr, sUch fiLterS have the pRobLem thaT thE TransmIssion Loss iNcReaSES or onLY ApProXiMate and insUFFicIent cHaRactEristicS can be obtained. The pROblEm of transmissIon Loss IS PaRtiCUlARly PrONouNCEd when the filter Is construcTeD Of A distributED elEmEnt filtEr such aS a micROstrip lIne circuiT. CategoriZeRs arE OFteN used in datA mining aPplicatioNS, wherE DaTa conTaiNed in a DaTabAse (or MultipLE daTabasEs) is anAlYzed anD used FoR various Purposes (such as to determiNe custOmer pUrcHasing habIts ANd pReferenceS or fOr other purPosEs). A CategOriZEr looKs at A DaTa iTEm (e.g., aRticLE, product, cUStOmeR, SToCk, support caLL, ANd sO fortH), anD DecideS, basEd on information asSOciated with the Item (E.G., TexT, coST, datE, dUration, buying hIstOrY, TRade voluMe, And so forth), wHether thE iTEm shoUld be aSsociaTed with A PArTIcular CateGorY or multipLe cAtEGories. THe CaTEgorizEr deCiDes whiCh of a sET of pOTEntial categories Most lIKEly apPLieS, descRiBes, or shOUld bE associateD with the datA item iN queStion. a “categoRy” Refers To a LaBel, annotatIOn, or
 of FIG. 27 can realize afilter wit h a c irc uit  c onfi gura tion easier to impl ement and smaller in l oss t ha n  the pr ocedu re of F I G. 2 6 c an .Fur th e r,  as a  mo dificat ion of FIG . 2 7,  a procedure is  known whi chuses a simpl e r eactan ce  fe e dback  pa th. F or thi s  proce dure, anac c urated esign t h e or y or  method for synth e si z ing the filter  fromth e  t a r get  ci rcuit netw or k fun c tion is no t k now n , and an appr oximation o r  an  empir ic alm ethodis us ed .  Fo r example,as s hown in t he cir c uit dia g ram ofFIG. 2 8,tra nsmi s si on  ze ro s  ar e  f orm e d b y combin in ga fil terb l o c k 8asa co nvent ional filterwit h ac oup lingeleme nt 9  c orres pondin g toabranch circuitor f eedback p ath .Bec au se of circui t s imp licity,  this p r oce du r e ha s the effect of re du c i ng  the los s, but si nc e  no accu ra tedesi g n  proc edur e sare know n fors yn th esizing  t he fil te r,the  desi g n re lies o n an app roxim a tion, which, t h erefore, hast he p ro b lemtha t only appr oxim a te c hara c te ris t ics c an be  o b ta i ned and the obtaine dcharac teris tics are notsufficient . A nother p roce d ur e  known in theart i s to combi n e a circ uit o f ladder  structur e with one  of  th e a bov e - de scribed trans m i ssio nzero fo rmi ng proc edu res , a ndto  thereaft er adjus tth egr oup  dela y  using a  p has eequ alize r . Acco rding  toth is pro cedure, it i s cl ai me d th atafilte r wi t h c onventi onal band pas s  cha ra ct eristic s can be obta in ed which h as  bo th a f l a t amplit ude characteristic anda  flat g rou p del ay c haracteri sti c thro ugh o ut the  passb and a nd  al s o  hast r an smi ss ion zerosi n  th e sto pb ands .
Howev er, this procedure als o has the pro ble m th a t  a ccu r at e  ch ar a cte r i stics cannot be  obtainedbe c au se the des i gnre lies on  an app roxim a tion; f urthermor e, the ci rc uitc o nfi guration b ecomes c omplex. M o reove r ,suchfil ters h av e t he pr oblemt hat  thetransm is sion l oss i nc reases o r only approximate andinsuff icien t c haracteri sti c s c an be obt aine d. The pro ble m o f tra nsm i ssion  los s  i s p a rticu larl y  pronounc e dwhe n th e filter is c o nst ructe d o f  a dis trib uted element filt e r such as a mi cros t r iplin e  cir cu it. Categorize rsar e often us ed  in data mi ning app li c ation s, whe re dat a conta i n ed in a d atab ase  (or mult ipl ed atabase s)  i s  analy zedan d used  for v a riou s purposes (such a s tod e termi n e c ustom er  purcha s inghabits and  preference s or f or o therpurpose s) . A ca teg or izer looks at a data  item  (e.g.,  a rtic le,  produ ct,c u stome r, s to ck,  supportc a ll ,  a nd sofort h), a nd  dec ides, bas e d on inf orm a tion as so cia t e d with th e item (e.g. , t ext,c o st, date,d urat i on ,  buyi ng his tory,trade v o lum e,  and so  fo r t h), wheth er the it e m s ho uldbe assoc ia tedwi thaparticular cate gory ormultiple c ategor ies .  The catego ri zer decideswhich  o f  a seto f  po tential cat ego rie s mo stlike l y applies, describes, or  sho uld b e  as socia ted w it h the da t a it em in qu e stion. A “cat egory” refers t o  al abel , a n no ta tion, or
 of_FIG. 27_can realize a filter_with a_circuit_configuration easier_to_implement and smaller_in loss than_the procedure of FIG._26 can.
Further, as_a_modification of FIG. 27, a procedure is known which uses a simple reactance feedback_path._For this_procedure,_an_accurate design theory or method_for synthesizing the filter from_the target_circuit network function is not known, and an_approximation_or an empirical_method is used. For example, as shown in the_circuit diagram of FIG. 28, transmission_zeros are formed_by_combining_a filter block 8_as a conventional filter with a_coupling element 9 corresponding to a_branch circuit or feedback path. Because of_circuit simplicity, this procedure has the_effect of reducing the loss,_but since_no accurate design procedures are_known for synthesizing_the filter,_the design relies_on an approximation, which, therefore, has_the problem that_only approximate characteristics can be obtained_and_the obtained characteristics_are_not_sufficient.
Another procedure_known in the_art_is to_combine_a circuit of ladder structure with_one_of the above-described transmission zero forming procedures,_and to thereafter adjust_the_group delay using a_phase equalizer. According to this_procedure, it is claimed that a_filter with_conventional bandpass_characteristics can be obtained which has both a flat amplitude characteristic_and a flat group delay characteristic_throughout the passband and_also has_transmission_zeros in the_stopbands.
However,_this procedure_also has the problem that accurate characteristics_cannot be_obtained because the design relies on_an approximation; furthermore, the_circuit_configuration becomes complex. Moreover, such filters_have the problem that the transmission_loss increases or only approximate_and_insufficient_characteristics can be obtained. The_problem of transmission loss is particularly_pronounced when the_filter is constructed of a distributed element_filter_such as a microstrip line circuit._Categorizers_are often used in data mining_applications,_where_data contained in a database_(or multiple databases) is analyzed and_used for various purposes (such as to determine customer_purchasing habits and_preferences or for other purposes)._A_categorizer_looks at a data item (e.g., article, product, customer, stock,_support call,_and so forth),_and decides, based on information associated with the item (e.g.,_text, cost, date, duration, buying history, trade_volume, and so forth), whether the item should be associated with_a particular category or multiple categories. The categorizer_decides which of a set of potential_categories most likely applies,_describes,_or should be associated with the data_item_in_question._A “category” refers_to a label,_annotation, or