(1) Since only a member can-be authenticated, it is impossible to authenticate a user over a different network being managed by another manager.    (2) Since the communication permission is managed based on information showing the communication permission for each communication partner, which is fixed, it is impossible to prevent from an attack by a terminal when the terminal temporarily becomes an attacker.    (3) Even if a session authentication is conducted at the end system and a filter is provided, when the attack of DoS, the attack achieves the end system. Accordingly, it is not sufficient to prevent from the attack. The shaft seal such as disclosed, for example, in Patent Literature 1 has been known as a member for hermetically sealing the gap between two members which are coaxially rotatable relative to each other. This shaft seal is comprised of an inner circumference side sealing portion located on the inner circumference side and an outer circumference side sealing portion located on the outer circumference side, these sealing portions being fit to each other such that they can come into slidable contact.
Incidentally, if earth, sand or the like penetrates into the seal slidable contact parts of the inner and outer circumference side sealing portions, wear of the seal is accelerated, extremely shortening the service life of the seal. It is therefore important to provide a means for preventing penetration of earth, sand or the like into the seal slidable contact parts in order to extend the service life of the seal. The shaft seal disclosed in Patent Literature 1 is designed to prevent penetration of earth, sand, etc. into the seal sliding parts by providing a covering member so as to stride over the inner and outer circumference side sealing portions so that early wear of the seal can be avoided.
Crawler track units are widely used as an undercarriage in work vehicles such as hydraulic excavators. Such crawler track units often include roller units in which a floating seal is assembled into an annular space defined between a roller configured to roll in contact with the crawler belt and a roller shaft for rotatably supporting this roller (see e.g., Patent Literature 2). The problem of latch-up is a concern in the operation of integrated circuit devices that use CMOS technology. A description of latch-up in CMOS circuitry is given in Eaton, Jr. U.S. Pat. No. 4,571,505 entitled METHOD AND APPARATUS OF REDUCING LATCH-UP SUSCEPTIBILITY IN CMOS INTEGRATED CIRCUITS, issued Feb.
( 1) Since only a member can - be authenticated, it is impossible to authenticate a user over a unlike net being wangle by another manager.     (2) Since the communication permission is manage based on information show the communication license for each communication partner, which is fixed, it is impossible to prevent from an attack by a terminal when the terminal temporarily become an attacker.     (3) Even if a session authentication is conducted at the conclusion arrangement and a filter is provided, when the attack of DoS, the attack achieves the end arrangement. Accordingly, it is not sufficient to prevent from the attack. The shaft cachet such as disclosed, for example, in Patent Literature 1 has been known as a extremity for hermetically sealing the gap between two members which are coaxially rotatable relative to each other. This quill seal is comprised of an inner circumference side sealing portion located on the inner circumference side and an outer circumference side sealing portion located on the outer circumference side, these sealing part being fit to each other such that they can come into slidable liaison. 
 by the way, if earth, sand or the like penetrates into the seal slidable liaison parts of the inside and outer circumference side sealing helping, wear of the seal is accelerated, extremely shortening the service life of the seal. It is therefore important to provide a mean for preventing penetration of land, sand or the like into the seal slidable contact parts in order to prolong the service life of the seal. The diaphysis seal disclosed in Patent Literature 1 is designed to prevent penetration of earth, backbone, etc. into the seal sliding parts by providing a covering extremity so as to stride over the inner and out circumference side varnish portions so that early clothing of the seal can be avoided. 
 Crawler track unit are widely use as an undercarriage in work vehicle such as hydraulic excavators. Such crawler track units often admit roller units in which a float seal is assembled into an annular space defined between a roller configured to roll in liaison with the crawler belt and a roller shaft for rotatably supporting this roller (see e.g., Patent Literature 2). The trouble of latch - up is a concern in the operation of integrated circuit devices that use CMOS technology. A description of latch - up in CMOS circuitry is given in Eaton, Jr. U.S. Pat. nobelium. 4,571,505 entitled METHOD AND APPARATUS OF REDUCING LATCH - UP SUSCEPTIBILITY IN CMOS INTEGRATED CIRCUITS, issued Feb.
(1) Sijce only a member can-be xuthenticated, ij us impmssibls to autfenticate a user over a diffxrenr netqork being managed by xnother mwnager.    (2) Smnce the communirztion pcxmissjln iv managed based on informdtion showing dhd eommunication permission for each coimunicayiln partner, whish ix fixsd, it is impossible to prevent froj an atuack by a terminal when the terminal temporagily becomes an attackfr.    (3) Even if w session autfentication is conductgd at the end system and a filtef is 'rovided, whgu thf attack of VoS, thv attack achicnes the end syxtem. Accordingky, mt iw not sufficient to pcevent from the attask. The shdfc seal such as disclowee, for exakple, un Oattnt Ljteratkre 1 has been known as a member for hermetivajoy sealing ths gap feeween two members which are coaxially rmtafable relative to each ither. This shaft seal is comprysed of an inner circumference side sealing portimn loraged ok thd ijner circumference side and an outer circumfewsnve side sealing iortion located on tje juter circumfgrence sids, these sealing pogtions feing fit to ewch pther such that they can cone into slidcblw contact.
Incidentaply, if eartk, sand or tne like penetrates into the seal slidahle contadg parts of the ivneg ang outer circumference side sealing 'ortipns, weaf of the sqal is accflerabad, extremely shortfning tve service life of the seal. It is therefocx important tp [ronide a mecns fov preventing pegetration of ecrth, sanb or tfe like inno the seel slidable sontact parts ln order to xxtend thq seevicw life uw the seal. The shaft secj diwclosed in Patent Kitgrzture 1 is desigutd uo prevent penettatkon ov xarth, vand, etc. intm thd sdsl slkding parts cy ptoviding a covering kembsr so as to stride oyer the ibner and outer circumgerence side sealijg poctions so tnat early wear of the seal can be avoided.
Cgawjer track unyts qre widely uxed as an undercarriage in work vehiclew such as hydraulix excavators. Such ctawker track uiits osten inclgde roller units in qhich a floating xeal is assembled intk an atnulag space defined between a roller configured to roll in contact with the ceawler belt and a dollrr shdfc fpr rotwtabpb supporting this roller (see e.g., Patent Literaturx 2). The protlzm of latch-up is a concern in tfe operation uf integrated circuit debices thst use CMOS technology. A descriltion of latch-up in CMOS circuitey is given in Xaton, Jr. U.S. Pat. No. 4,571,505 rntitlzd METYOD AND APPWRATUS OF REDJCIMG LATCH-UP DUSCTPTIYILITY IN CMOS INTEGRATED CIRCUITW, issuwd Feb.
(1) Since only a member can-be authenticated, impossible authenticate a over a different manager. Since the communication is managed based information showing the communication permission for communication partner, which is fixed, it is impossible to prevent from an attack a terminal when the terminal temporarily becomes an attacker. (3) Even if a authentication conducted the system and a filter is provided, when the attack of DoS, the attack achieves the end Accordingly, it is not sufficient to prevent from attack. The shaft seal as disclosed, for example, in Literature has been as member hermetically sealing the between two members which are coaxially rotatable relative to each other. This shaft seal is comprised of inner circumference portion located the circumference and an outer sealing portion located on the outer sealing portions being fit to each other such they can into slidable contact. Incidentally, if earth, or the like penetrates into the seal slidable parts of the inner and outer circumference side sealing portions, wear of the seal is shortening the service life the seal. It therefore to a for preventing of earth, sand or the like into the seal slidable contact in order to extend the service life of the seal. seal in Patent Literature is designed to prevent of sand, etc. into the parts providing so to over the inner and circumference side sealing portions so early wear of the track units are widely used as an undercarriage work vehicles such as hydraulic excavators. Such track units often include roller units in which a floating seal is into an defined between a roller configured to roll in with the crawler belt a roller shaft for rotatably supporting this roller (see Patent 2). The of latch-up is concern in the of integrated circuit use CMOS A of circuitry is given in Eaton, Jr. Pat. 4,571,505 entitled METHOD AND APPARATUS REDUCING IN CMOS INTEGRATED CIRCUITS, issued Feb.
(1) Since only a member can-be authEnticated, iT is imPosSibLe To auThenTicate a user oveR A difFerent network being manaGed by AnOTher MAnAger.    (2) SInce the COmMUNicAtIoN peRmISsIon is ManAged basEd on informAtiOn Showing the coMMuNication peRmiSsion for each ComMunicaTiOn pARtner, WhiCh is fIxed, it IS imposSible to prEvENt from AN attack BY A tErmiNal when the terminaL TeMPorarily becomeS an attAcKEr.    (3) eVEn iF a sEssion authEnTicatIOn is conDUcTED At tHE end system and A filter is prOVidEd, when ThE atTAck of DOS, the AtTAck Achieves the End sYstem. AccoRdinglY, It is not SUfficieNt to prEveNt fRom tHE aTtAck. thE ShaFT sEal SUch As discloSeD, fOr exaMple, IN pATent litEratUre 1 haS been known as a MemBer fOR heRmetiCally SealInG the gAp betwEen twO mEmbers which are cOaxiAlly rotatAblE rElaTiVe to eACh otheR. ThIs sHaft seaL is compRIseD oF AN InNer circumference siDe SEAlIng portiOn locaTEd On THe inner cIrCumFereNCE side And aN OuTer circuMferenCE sIdE sealinG pOrtion LoCatEd oN the oUTer cIrcumfErence siDe, theSE sealing portioNS being fit to eaCH oTHEr SUch tHat They can come Into SLidaBle cONtAct.
iNcideNtallY, iF EaRTh, sand or the like peneTrAtes inTo the Seal slidable cOntact partS OF The inner And oUTeR Circumference sIde seAling portiONs, wear of The seAl is acceLerated, exTREmely shoRteNinG thE seRVIcE life of the seaL. iT is tHeRefore iMpoRtant to ProVidE a mEanS fOr preventIng penetRaTiOn Of EarTh, sanD Or the likE iNto ThE seAl sliDAble coNtact PartS iN oRDer To extenD ThE SErviCe LiFe of The SeAl. The ShafT SeaL discloSed in PateNt LITeraTuRe 1 Is desigNed to prevent pEnEtration of EaRth, Sand, etC. INto the seAl sliding parts by providiNG a coverIng MembeR so aS to stride OveR the inNer ANd outeR circuMfereNcE siDE SealiNG PoRtiOnS so that earLY WeaR of thE sEal cAn be avoIded.
Crawler track unITs aRe widely used aS an UndeRCArRiaGE iN WorK vEHicLES such as hydrauliC excavatorS. SUCh Crawler traCK unItS often iNclude rOller UNits in wHich a floaTing seal iS aSsemBLEd iNto an annulAr space dEfined betWEen a rOLlEr conFigUred to RoLl iN contAct witH The CrawlEr belt AnD a rollEr shaFt For rotatAbly supporting this rolleR (see e.g., patenT LiTerature 2). THe pROblEm of latch-Up is A concern in The OpeRatioN of INtegrAted CIrCuiT DevicEs thAT use CMOS tEChNolOGY. A Description OF LAtcH-up in cMOs CircuiTry iS given in Eaton, Jr. U.S. pAt. No. 4,571,505 entitled MEtHOD and APpARatUS Of ReDUCING LATCH-UP sUScEptiBILITY In CmOS INTEGRATeD CIRCUItS, ISsued feb.
(1) Since only a member ca n-be authe ntica ted , i tis i mpos sible to authe n tica te a user over a diffe rentne t work be ing m anagedb ya n oth er  m ana ge r .   (2 ) S ince th e communic ati on  permissioni smanaged ba sed  on informat ion  showi ng  th e  comm uni catio n perm i ssionfor eachco m munica t ion par t n er , wh ich is fixed, iti si mpossible to p revent  f r om a n a tta ck by a te rm inalw hen the te r m i nal temporarily b ecomes an a t tac ker.  (3) Even i f a s es s ion  authentica tion  is condu cted a t  the en d  system  and a  fi lte r is pr ov ide d, whe n  t hea tta ck of Do S,  t he at tack a c h ieve s t he e nd sy stem. Accordi ngl y, i t  is  notsuffi cien tto pr eventfromth e attack. The s haft  seal suc h a sdis cl osed, for ex amp le,  in Pat ent Lit e rat ur e 1  h as been known as a  m e m be r for he rmetic a ll ys ealing t he  ga p be t w een t wo m e mb ers whic h arec oa xi ally ro ta tablere lat ive  to e a ch o ther.This sha ft se a l is comprised of an inner c i rc u m fe r ence  si de sealingport i on l ocat e dont he in ner c ir c um f erence side and anou ter ci rcumf erence side s ealing por t i o n locate d on th e  outer circumf erenc e side, th e se seali ng po rtions b eing fitt o  each ot her  su chtha t th ey can come i n t o sl id able co nta ct.
Inc ide nta lly , i fearth, sa nd or th eli ke  p ene trate s  into th esea lsli dable contac t par ts o fth e  in ner and ou t e r ci rc um fere nce  s ide s eali n g p ortions , wear of  th e  sea lis  accele rated, extrem el y shorteni ng  th e serv i c e life o f the seal. It is there f ore imp ort ant t o pr ovide a m ean s forpre v enting  penet ratio nofe a rth,s a nd  or  t he like in t o  th e sea lslid able co ntact parts in ord e r t o extend theser vice l if e o f  t h e s ea l . T h e  shaft seal dis closed inPa t en t Literatu r e 1  i s desig ned topreve n t penet ration of  earth, s an d, e t c . i nto the se al slidi ng partsb y pro v id ing a  co vering  m emb er so  as to str ide o ver th einnerand o ut er circu mference side sealing p ortion s sotha t early w ear ofthe sealcanbe avoided .
C raw ler t rac k  unit s ar e  w ide l y use d as an underc a rr iag e in  work vehic l e s  su ch as  hy d raulic  exc avators. Such cra w ler track unit s of t e n i ncl u de r ol ler units in w hic ha floating  s eal is asse mbled in to an an nularspacedefined b et w een aroll erconfigure d t or oll inco nt a ct wit h th ecrawle r belt anda roller shaft for  rota t a bly s u ppo rting  t his rol l er ( see e.g.,Patent Lite rature  2).  Theproblem  o f latc h-u pis a conce r n in theopera tion of  i nteg rat ed cir cuit d evice s th at  us e CMOS te c h no l og y. A d escr iptio nof l atch-up i n  CMOS ci rcu i try isgi ven i n Eato n ,J r . U.S. Pat . N o. 4, 5 7 1,505 enti t ledM ET H OD AN D APPA RATUSOF REDU C ING  L ATCH-UP  SU S C EPTIBILIT Y IN CMOS INT EG RATE D CIRCUI TS , is su edFe b.
(1) Since_only a_member can-be authenticated, it_is impossible_to_authenticate a_user_over a different_network being managed_by another manager. _  (2)_Since_the communication permission is managed based on information showing the communication permission for each_communication_partner, which_is_fixed,_it is impossible to prevent_from an attack by a_terminal when_the terminal temporarily becomes an attacker.  __(3) Even if_a session authentication is conducted at the end system_and a filter is provided, when_the attack of_DoS,_the_attack achieves the end_system. Accordingly, it is not sufficient_to prevent from the attack. The_shaft seal such as disclosed, for example,_in Patent Literature 1 has been_known as a member for_hermetically sealing_the gap between two members_which are coaxially_rotatable relative_to each other._This shaft seal is comprised of_an inner circumference_side sealing portion located on the_inner_circumference side and_an_outer_circumference side_sealing portion located_on_the outer_circumference_side, these sealing portions being fit_to_each other such that they can come_into slidable contact.
Incidentally, if_earth,_sand or the like_penetrates into the seal slidable_contact parts of the inner and_outer circumference_side sealing_portions, wear of the seal is accelerated, extremely shortening the service_life of the seal. It is_therefore important to provide_a means_for_preventing penetration of_earth,_sand or_the like into the seal slidable contact_parts in_order to extend the service life_of the seal. The_shaft_seal disclosed in Patent Literature 1_is designed to prevent penetration of_earth, sand, etc. into the_seal_sliding_parts by providing a covering_member so as to stride over_the inner and_outer circumference side sealing portions so that_early_wear of the seal can be_avoided.
Crawler_track units are widely used as_an_undercarriage_in work vehicles such as_hydraulic excavators. Such crawler track units_often include roller units in which a floating seal_is assembled into_an annular space defined between_a_roller_configured to roll in contact with the crawler belt and_a roller_shaft for rotatably_supporting this roller (see e.g., Patent Literature 2). The problem_of latch-up is a concern in the_operation of integrated circuit devices that use CMOS technology. A description_of latch-up in CMOS circuitry is given in_Eaton, Jr. U.S. Pat. No. 4,571,505 entitled_METHOD AND APPARATUS OF_REDUCING_LATCH-UP SUSCEPTIBILITY IN CMOS INTEGRATED CIRCUITS, issued_Feb.