SIFT特征提取算法詳解

1、SIFT特征提取算法詳解SIFT特征提取算法總結(jié)主要步驟1）、尺度空間的生成2）、檢測(cè)尺度空間極值點(diǎn)3）、精確定位極值點(diǎn);4）、為每個(gè)關(guān)鍵點(diǎn)指定方向參數(shù)；5）、關(guān)鍵點(diǎn)描述子的生成。尺度克同拋生蕉尺廢空間理論目的是惶齷鐐數(shù)局的要尺度特fit.iW斯塞蹦是實(shí)現(xiàn)尺度變換的唯Trtfe.予是一同二隼圈隙的尺度空間定義Lx,y.cr）G（x.ytcr）*/（x,j.）其中一gj.cr）是尺度可梟/本心股1.471.L''.'r'工Ttr0（.y）是交間里標(biāo)曾是尺度坐標(biāo)的大小決定昭弊的平滑慢度r大尺度對(duì)應(yīng)圖瞰的慨貌恃抵；小尺酬心口像的細(xì)節(jié)恃SL大曲值對(duì)宓相忸尺度（低分辨罩）

2、.反渴正精細(xì)尺直僖分測(cè)路網(wǎng)m引或或分尺度w間舊。g和:才出沖金分。與J；6=（G七F幽-tX，V.1；e）*/（XV）="X,JLfer）-2（.七4b）L（x,y,o-）,o-=1.6agoodtradeoffinstrumenthasasingletestcondition,willbetransferredtothecoordinationofthetestphase,theinstrumentaccordingtothestand-alonetrialsscheduled,withtheprocesspreparationoftestsolutions,equippedwit

3、hprofessionaltechniciansandskilledworkers,toensuresafetyandquality.6.constructionspecification6.1.1siteequipment,andindustrialpipelineweldingengineeringconstructionandtheacceptancespecificationGB50268-976.1.2oilchemicaltoxic,andcanburningmediapipelineengineeringconstructionandtheacceptancespecificat

4、ionSH3501-20026.1.3oilchemicallowtemperaturesteelweldingproceduresSH/T352020046.1.4oilchemicalchromenickelAustrian'sbodysteel,andironnickelalloyandnickelalloypipelineweldingproceduresSH/T3523-19996.1.5SHJ520-92petrochemicalengineeringtechnicalspecificationforweldingofCR-MOheat-resistantsteelpipe

5、6.1.6ofthepressurevesselNDT4730-946.2JBweldpreparation6.2.1constructionaccordingtothematerialsoftheprojectspecificationsandweldingmethods,providingqualifiedweldingprocedurequalificationreport.6.2.2qualifiedweldingprocedurequalificationbasedonthepreparationofweldinginstruction,guidethewelderweldingop

6、erations.6.2.3whereparticipationinsitewelding,mustbeinpossessionofboilerandpressurevesselweldercertificatesissuedbytheLaborDepartment.6.2.4whereinvolvedinthepipeandsteelstructureweldingwelders,welderbeforeentryexaminationsshouldattendtheowners,andconstructionshouldbemadewithinthescopeandeligibilitya

7、pprovedbythequalityandtechnologysupervisiondepartmentsandowners.6.2.5qualifyforweldingwelder,weldingprocess,shouldbeapprovedbyweldingtheweldingprocess.D(x,y,o-),o-=1.6agoodtradeoffinstrumenthasasingletestcondition,willbetransferredtothecoordinationofthetestphase,theinstrumentaccordingtothestandalone

8、trialsscheduled,withtheprocesspreparationoftestsolutions,equippedwithprofessionaltechniciansandskilledworkers,toensuresafetyandquality.6.weldingengineeringconstructionprogramme6.1thisengineeringusedconstructionspecification6.1.1siteequipment,andindustrialpipelineweldingengineeringconstructionandthea

9、cceptancespecificationGB50268-976.1.2oilchemicaltoxic,andcanburningmediapipelineengineeringconstructionandtheacceptancespecificationSH3501-20026.1.3oilchemicallowtemperaturesteelweldingproceduresSH/T3520-20046.1.4oilchemicalchromenickelAustrian'sbodysteel,andironnickelalloyandnickelalloypipeline

10、weldingproceduresSH/T3523-19996.1.5SHJ520-92petrochemicalengineeringtechnicalspecificationforweldingofCR-MOheat-resistantsteelpipe6.1.6ofthepressurevesselNDT4730-946.2JBweldpreparation6.2.1constructionaccordingtothematerialsoftheprojectspecificationsandweldingmethods,providingqualifiedweldingprocedu

11、requalificationreport.6.2.2qualifiedweldingprocedurequalificationbasedonthepreparationofweldinginstruction,guidethewelderweldingoperations.6.2.3whereparticipationinsitewelding,mustbeinpossessionofboilerandpressurevesselweldercertificatesissuedbytheLaborDepartment.6.2.4whereinvolvedinthepipeandsteels

12、tructureweldingwelders,welderbeforeentryexaminationsshouldattendtheowners,andconstructionshouldbemadewithinthescopeandeligibilityapprovedbythequalityandtechnologysupervisiondepartmentsandowners.6.2.5qualifyforweldingwelder,weldingprocess,shouldbeapprovedbyweldingtheweldingprocess.關(guān)于尺度空間的理解說(shuō)明:圖中的2是必須

13、的，尺度空間是連續(xù)的。在Lowe的論文中，將第0層的初始尺度定為1.6，圖片的初始尺度定為0.5.在檢測(cè)極值點(diǎn)前對(duì)原始圖像的高斯平滑以致圖像丟失高頻信息，所以Lowe建議在建立尺度空間前首先對(duì)原始圖像長(zhǎng)寬擴(kuò)展一倍，以保留原始圖像信息，增加特征點(diǎn)數(shù)量。尺度越大圖像越模糊。4 nGriUliSidn 0DG J降采樣得到（如2）nextoctave是由firstoctave2Tg.kok'b:k'fb）上二2%尺度空間的所有取值，s為每組層數(shù)，一般為35在DOCX度空間下的極值點(diǎn)檢例尺度空同硬低點(diǎn)F丁手粒尺&三司的蔓值口，拒一個(gè)三件點(diǎn)要和個(gè)"有的相部點(diǎn)比校,看其是

14、否比它的圖驟域和用翻閔相部點(diǎn)大戒者小.如區(qū).不同然吟測(cè)電和它同尺度的8小相曾二F帽銅尺.爸"底的9*我電步茂個(gè)點(diǎn)曦.以痛保在尺度空?qǐng)D和工國(guó)修堂間都住惻到超值點(diǎn).如累一個(gè),瑞在口。物度壬聞t理4馬上F網(wǎng)層的26八酒瓶牡是最大或最小值時(shí).就認(rèn)為誤點(diǎn)是圖埋在該尺痍下的一個(gè)樗任員Q同一組中的相鄰尺度（由于k的取值關(guān)系，肯定是上下層）之間進(jìn)行尋找instrumenthasasingletestcondition,willbetransferredtothecoordinationofthetestphase,theinstrumentaccordingtothestandalonetrials

15、scheduled,withtheprocesspreparationoftestsolutions,equippedwithprofessionaltechniciansandskilledworkers,toensuresafetyandquality.6.weldingengineeringconstructionprogramme6.1thisengineeringusedconstructionspecification6.1.1siteequipment,andindustrialpipelineweldingengineeringconstructionandtheaccepta

16、ncespecificationGB50268-976.1.2oilchemicaltoxic,andcanburningmediapipelineengineeringconstructionandtheacceptancespecificationSH3501-20026.1.3oilchemicallowtemperaturesteelweldingproceduresSH/T3520-20046.1.4oilchemicalchromenickelAustrian'sbodysteel,andironnickelalloyandnickelalloypipelineweldin

17、gproceduresSH/T3523-19996.1.5SHJ520-92petrochemicalengineeringtechnicalspecificationforweldingofCR-MOheat-resistantsteelpipe6.1.6ofthepressurevesselNDT4730-946.2JBweldpreparation6.2.1constructionaccordingtothematerialsoftheprojectspecificationsandweldingmethods,providingqualifiedweldingprocedurequal

18、ificationreport.6.2.2qualifiedweldingprocedurequalificationbasedonthepreparationofweldinginstruction,guidethewelderweldingoperations.6.2.3whereparticipationinsitewelding,mustbeinpossessionofboilerandpressurevesselweldercertificatesissuedbytheLaborDepartment.6.2.4whereinvolvedinthepipeandsteelstructu

19、reweldingwelders,welderbeforeentryexaminationsshouldattendtheowners,andconstructionshouldbemadewithinthescopeandeligibilityapprovedbythequalityandtechnologysupervisiondepartmentsandowners.6.2.5qualifyforweldingwelder,weldingprocess,shouldbeapprovedbyweldingtheweldingprocess.在極值比較的過(guò)程中，每一組圖像的首末兩層是無(wú)法進(jìn)行

20、極值比較的，為了滿足尺度變化的連續(xù)性，我們?cè)诿恳唤M圖像的頂層繼續(xù)用高斯模糊生成了3幅圖像,高斯金字塔有每組S+3層圖像。DO陵字塔每組有S+2層圖像.instrumenthasasingletestcondition,willbetransferredtothecoordinationofthetestphase,theinstrumentaccordingtothestandalonetrialsscheduled,withtheprocesspreparationoftestsolutions,equippedwithprofessionaltechniciansandskilledwor

21、kers,toensuresafetyandquality.6.weldingengineeringconstructionprogramme6.1thisengineeringusedconstructionspecification6.1.1siteequipment,andindustrialpipelineweldingengineeringconstructionandtheacceptancespecificationGB50268-976.1.2oilchemicaltoxic,andcanburningmediapipelineengineeringconstructionan

22、dtheacceptancespecificationSH3501-20026.1.3oilchemicallowtemperaturesteelweldingproceduresSH/T3520-20046.1.4oilchemicalchromenickelAustrian'sbodysteel,andironnickelalloyandnickelalloypipelineweldingproceduresSH/T3523-19996.1.5SHJ520-92petrochemicalengineeringtechnicalspecificationforweldingofCR-

23、MOheat-resistantsteelpipe6.1.6ofthepressurevesselNDT4730-946.2JBweldpreparation6.2.1constructionaccordingtothematerialsoftheprojectspecificationsandweldingmethods,providingqualifiedweldingprocedurequalificationreport.6.2.2qualifiedweldingprocedurequalificationbasedonthepreparationofweldinginstructio

24、n,guidethewelderweldingoperations.6.2.3whereparticipationinsitewelding,mustbeinpossessionofboilerandpressurevesselweldercertificatesissuedbytheLaborDepartment.6.2.4whereinvolvedinthepipeandsteelstructureweldingwelders,welderbeforeentryexaminationsshouldattendtheowners,andconstructionshouldbemadewith

25、inthescopeandeligibilityapprovedbythequalityandtechnologysupervisiondepartmentsandowners.6.2.5qualifyforweldingwelder,weldingprocess,shouldbeapprovedbyweldingtheweldingprocess.通過(guò)哪三維二次性融以精蝎網(wǎng)定關(guān)植威駒位置源度（這手畫(huà)博素精度同時(shí)去除低對(duì)闿S的關(guān)鍵良剎不楣定的邊緣響應(yīng)點(diǎn),因?yàn)镈OG算子會(huì)產(chǎn)生軟老的辿族呵匠），以圖箱匹叱便定旦.苣方忖師生挹J，R空間尺度通鞅11)IMj；工，&2&*親導(dǎo)3H算為。

26、13到精琳的位室次-值在己及檢測(cè)到的捋征點(diǎn)中要去掉（0對(duì)比庶居而怔最壞穗定的邊舞喧瞪點(diǎn).鏘低對(duì)比度的點(diǎn)上把公式（2戕人公式（11只翱耐項(xiàng)可得，1>jVJ?r-Ivcr-+-yX=(x,y.af2&若喬。嗎談特征點(diǎn)就保留下來(lái)否則舍科醛埠響座的瑞.一個(gè)定義不好的高斯差分算子的極值礎(chǔ)聘邊部的地方有較大的主曲本.而在垂直邊算的方向有軟石州主向電主曲本通過(guò)一個(gè)丁工7的Ha筋相牛沖莖上f口D1ff=+'=DfD1,L®«身裁由采樣點(diǎn)相鄰差估tt得到.D的主曲率和H的特亞值成正比.力最大特征值.耳為量”的恃征值.迎| l' f I | I -"J

27、J. 一 內(nèi)即 N W”U IIII « I i11II-=Flpi+%=ei*'i令S-Rr貝"iIfratio>(r+1)2/(r),throwitout(SIFTusesr=10)表示DOG&字塔中某一尺度的圖像x方向求導(dǎo)兩次通過(guò)擬和三維二次函數(shù)以精確確定關(guān)鍵點(diǎn)的位置和尺度（達(dá)到亞像素精度）,instrumenthasasingletestcondition,willbetransferredtothecoordinationofthetestphase,theinstrumentaccordingtothestandalonetrialssch

28、eduled,withtheprocesspreparationoftestsolutions,equippedwithprofessionaltechniciansandskilledworkers,toensuresafetyandquality.6.weldingengineeringconstructionprogramme6.1thisengineeringusedconstructionspecification6.1.1siteequipment,andindustrialpipelineweldingengineeringconstructionandtheacceptance

29、specificationGB50268-976.1.2oilchemicaltoxic,andcanburningmediapipelineengineeringconstructionandtheacceptancespecificationSH3501-20026.1.3oilchemicallowtemperaturesteelweldingproceduresSH/T3520-20046.1.4oilchemicalchromenickelAustrian'sbodysteel,andironnickelalloyandnickelalloypipelineweldingpr

30、oceduresSH/T3523-19996.1.5SHJ520-92petrochemicalengineeringtechnicalspecificationforweldingofCR-MOheat-resistantsteelpipe6.1.6ofthepressurevesselNDT4730-946.2JBweldpreparation6.2.1constructionaccordingtothematerialsoftheprojectspecificationsandweldingmethods,providingqualifiedweldingprocedurequalifi

31、cationreport.6.2.2qualifiedweldingprocedurequalificationbasedonthepreparationofweldinginstruction,guidethewelderweldingoperations.6.2.3whereparticipationinsitewelding,mustbeinpossessionofboilerandpressurevesselweldercertificatesissuedbytheLaborDepartment.6.2.4whereinvolvedinthepipeandsteelstructurew

32、eldingwelders,welderbeforeentryexaminationsshouldattendtheowners,andconstructionshouldbemadewithinthescopeandeligibilityapprovedbythequalityandtechnologysupervisiondepartmentsandowners.6.2.5qualifyforweldingwelder,weldingprocess,shouldbeapprovedbyweldingtheweldingprocess.為每個(gè)關(guān)鍵點(diǎn)指定方向參蚣刎以關(guān)犍點(diǎn)都城鐮素的悌度方向分布

33、持性為法個(gè)關(guān)鍵電指定方間參班變單于具善芯轉(zhuǎn)齊變忖RCidJ-tUw缸工晴Nhjz+D-Ki-LxM)式中出漢力姓憐芟的國(guó)道如內(nèi)間公式嚴(yán)其中時(shí)用的尺度為福個(gè)美維點(diǎn)臺(tái)自斫在晌尺度.一至比，圖球的美硬點(diǎn)已喊完畢,每廣寺提點(diǎn)有二個(gè)倍品心系所處尺度.方向.由此可以碉定一個(gè)8格喃詼域.直方圖中的峰值就是主方向，其他的達(dá)到最大值80%勺方向可作為輔助方向IdentifypeakandassignorientationandsumofmagnitudetokeypointTheusermaychooseathresholdtoexcludekeypointsbasedontheirassignedsumofm

34、agnitudes.利用關(guān)鍵點(diǎn)鄰域像素的梯度方向分布特性為每個(gè)關(guān)鍵點(diǎn)指定方向參數(shù)，使算子具備旋轉(zhuǎn)不變性。以關(guān)鍵點(diǎn)為中心的鄰域窗口內(nèi)采樣，并用直方圖統(tǒng)計(jì)鄰域像素的梯度方向。梯度直方圖的范圍是0,360度，其中每10度一個(gè)柱，總共36個(gè)柱。隨著距中心點(diǎn)越遠(yuǎn)的領(lǐng)域其對(duì)直方圖的貢獻(xiàn)也響應(yīng)減小.Lowe論文中還提到要使用高斯函數(shù)對(duì)直方圖進(jìn)行平滑，減少突變的影響instrumenthasasingletestcondition,willbetransferredtothecoordinationofthetestphase,theinstrumentaccordingtothestandalonetria

35、lsscheduled,withtheprocesspreparationoftestsolutions,equippedwithprofessionaltechniciansandskilledworkers,toensuresafetyandquality.6.weldingengineeringconstructionprogramme6.1thisengineeringusedconstructionspecification6.1.1siteequipment,andindustrialpipelineweldingengineeringconstructionandtheaccep

36、tancespecificationGB50268-976.1.2oilchemicaltoxic,andcanburningmediapipelineengineeringconstructionandtheacceptancespecificationSH3501-20026.1.3oilchemicallowtemperaturesteelweldingproceduresSH/T3520-20046.1.4oilchemicalchromenickelAustrian'sbodysteel,andironnickelalloyandnickelalloypipelineweld

37、ingproceduresSH/T3523-19996.1.5SHJ520-92petrochemicalengineeringtechnicalspecificationforweldingofCR-MOheat-resistantsteelpipe6.1.6ofthepressurevesselNDT4730-946.2JBweldpreparation6.2.1constructionaccordingtothematerialsoftheprojectspecificationsandweldingmethods,providingqualifiedweldingprocedurequ

38、alificationreport.6.2.2qualifiedweldingprocedurequalificationbasedonthepreparationofweldinginstruction,guidethewelderweldingoperations.6.2.3whereparticipationinsitewelding,mustbeinpossessionofboilerandpressurevesselweldercertificatesissuedbytheLaborDepartment.6.2.4whereinvolvedinthepipeandsteelstruc

39、tureweldingwelders,welderbeforeentryexaminationsshouldattendtheowners,andconstructionshouldbemadewithinthescopeandeligibilityapprovedbythequalityandtechnologysupervisiondepartmentsandowners.6.2.5qualifyforweldingwelder,weldingprocess,shouldbeapprovedbyweldingtheweldingprocess.關(guān)鍵點(diǎn)描述子的生成步驟旋轉(zhuǎn)主將坐揉軸旋轉(zhuǎn)為關(guān)鍵

40、點(diǎn)的方向，以硅.蜂旅華不變爛生成描 述子它于一.卜H淳古丁二128卜文據(jù),M最終形或128絕的SIFT特征店量將特工亢量由姓笠臼一化.則可以進(jìn)一步去除光照變化的影響.通過(guò)對(duì)關(guān)鍵點(diǎn)周?chē)鷪D像區(qū)域分塊，計(jì)算塊內(nèi)梯度直方圖，生成具有獨(dú)特性的向量，這個(gè)向量是該區(qū)域圖像信息的一種抽象，具有唯一性。關(guān)鍵點(diǎn)撰述十的生成首光書(shū)坐標(biāo)旗耨為關(guān)慨氨的方向.以源保簟輔就性.以特征點(diǎn)為中心里8彝鄰域作為崇祥窗口，將崇祥點(diǎn)與特髭您的相前方向通工高勘印在后閂入巨吉R個(gè)K同直方圖，呆后濱得29”8的8羅特於攔苜二.不苣困也下，訕y 卯依疔心巾ticst npior每一個(gè)小格都代表了特征點(diǎn)鄰域所在的尺度空間的一個(gè)像素，箭頭方向代

41、表了像素梯度方向，箭頭長(zhǎng)度代表該像素的幅值。然后在4X4的窗口內(nèi)計(jì)算8個(gè)方向的梯度方向直方圖。繪制每個(gè)梯度方向的累加可形成一個(gè)種子點(diǎn)。instrumenthasasingletestcondition,willbetransferredtothecoordinationofthetestphase,theinstrumentaccordingtothestandalonetrialsscheduled,withtheprocesspreparationoftestsolutions,equippedwithprofessionaltechniciansandskilledworkers,toe

42、nsuresafetyandquality.6.weldingengineeringconstructionprogramme6.1thisengineeringusedconstructionspecification6.1.1siteequipment,andindustrialpipelineweldingengineeringconstructionandtheacceptancespecificationGB50268-976.1.2oilchemicaltoxic,andcanburningmediapipelineengineeringconstructionandtheacce

43、ptancespecificationSH3501-20026.1.3oilchemicallowtemperaturesteelweldingproceduresSH/T3520-20046.1.4oilchemicalchromenickelAustrian'sbodysteel,andironnickelalloyandnickelalloypipelineweldingproceduresSH/T3523-19996.1.5SHJ520-92petrochemicalengineeringtechnicalspecificationforweldingofCR-MOheat-r

44、esistantsteelpipe6.1.6ofthepressurevesselNDT4730-946.2JBweldpreparation6.2.1constructionaccordingtothematerialsoftheprojectspecificationsandweldingmethods,providingqualifiedweldingprocedurequalificationreport.6.2.2qualifiedweldingprocedurequalificationbasedonthepreparationofweldinginstruction,guidet

45、hewelderweldingoperations.6.2.3whereparticipationinsitewelding,mustbeinpossessionofboilerandpressurevesselweldercertificatesissuedbytheLaborDepartment.6.2.4whereinvolvedinthepipeandsteelstructureweldingwelders,welderbeforeentryexaminationsshouldattendtheowners,andconstructionshouldbemadewithinthesco

46、peandeligibilityapprovedbythequalityandtechnologysupervisiondepartmentsandowners.6.2.5qualifyforweldingwelder,weldingprocess,shouldbeapprovedbyweldingtheweldingprocess.每個(gè)直方圖有8方向的梯度方向，每一個(gè)描述符包含一個(gè)位于關(guān)鍵點(diǎn)附近的四個(gè)直方圖數(shù)組.這就導(dǎo)致了SIFT的特征向量有128維.（先是一個(gè)4X4的來(lái)計(jì)算出一個(gè)直方圖，每個(gè)直方圖有8個(gè)方向。所以是4X4X8=128維）將這個(gè)向量歸一化之后，就進(jìn)一步去除了光照的影響。旋轉(zhuǎn)為

47、主方向instrumenthasasingletestcondition,willbetransferredtothecoordinationofthetestphase,theinstrumentaccordingtothestandalonetrialsscheduled,withtheprocesspreparationoftestsolutions,equippedwithprofessionaltechniciansandskilledworkers,toensuresafetyandquality.6.weldingengineeringconstructionprogramme6

48、.1thisengineeringusedconstructionspecification6.1.1siteequipment,andindustrialpipelineweldingengineeringconstructionandtheacceptancespecificationGB50268-976.1.2oilchemicaltoxic,andcanburningmediapipelineengineeringconstructionandtheacceptancespecificationSH3501-20026.1.3oilchemicallowtemperaturestee

49、lweldingproceduresSH/T3520-20046.1.4oilchemicalchromenickelAustrian'sbodysteel,andironnickelalloyandnickelalloypipelineweldingproceduresSH/T3523-19996.1.5SHJ520-92petrochemicalengineeringtechnicalspecificationforweldingofCR-MOheat-resistantsteelpipe6.1.6ofthepressurevesselNDT4730-946.2JBweldprep

50、aration6.2.1constructionaccordingtothematerialsoftheprojectspecificationsandweldingmethods,providingqualifiedweldingprocedurequalificationreport.6.2.2qualifiedweldingprocedurequalificationbasedonthepreparationofweldinginstruction,guidethewelderweldingoperations.6.2.3whereparticipationinsitewelding,m

51、ustbeinpossessionofboilerandpressurevesselweldercertificatesissuedbytheLaborDepartment.6.2.4whereinvolvedinthepipeandsteelstructureweldingwelders,welderbeforeentryexaminationsshouldattendtheowners,andconstructionshouldbemadewithinthescopeandeligibilityapprovedbythequalityandtechnologysupervisiondepa

52、rtmentsandowners.6.2.5qualifyforweldingwelder,weldingprocess,shouldbeapprovedbyweldingtheweldingprocess.工2A雄美健點(diǎn)描述于生或步Jft勒之計(jì)玨述F所名的圖像坦墩留述于梯度方向比牙盤(pán)由關(guān)鍵點(diǎn)所旄又腐的模糊用體計(jì)”產(chǎn)生.明?；芈?lián)的串在通道下式計(jì)R：加父,上*3-1，+1mdw-=-=2G門(mén)算美所后維（oC”E）的頓內(nèi)尺龍,=4instrumenthasasingletestcondition,willbetransferredtothecoordinationofthetestphase,th

53、einstrumentaccordingtothestandalonetrialsscheduled,withtheprocesspreparationoftestsolutions,equippedwithprofessionaltechniciansandskilledworkers,toensuresafetyandquality.6.weldingengineeringconstructionprogramme6.1thisengineeringusedconstructionspecification6.1.1siteequipment,andindustrialpipelinewe

54、ldingengineeringconstructionandtheacceptancespecificationGB50268-976.1.2oilchemicaltoxic,andcanburningmediapipelineengineeringconstructionandtheacceptancespecificationSH3501-20026.1.3oilchemicallowtemperaturesteelweldingproceduresSH/T3520-20046.1.4oilchemicalchromenickelAustrian'sbodysteel,andir

55、onnickelalloyandnickelalloypipelineweldingproceduresSH/T3523-19996.1.5SHJ520-92petrochemicalengineeringtechnicalspecificationforweldingofCR-MOheat-resistantsteelpipe6.1.6ofthepressurevesselNDT4730-946.2JBweldpreparation6.2.1constructionaccordingtothematerialsoftheprojectspecificationsandweldingmetho

56、ds,providingqualifiedweldingprocedurequalificationreport.6.2.2qualifiedweldingprocedurequalificationbasedonthepreparationofweldinginstruction,guidethewelderweldingoperations.6.2.3whereparticipationinsitewelding,mustbeinpossessionofboilerandpressurevesselweldercertificatesissuedbytheLaborDepartment.6

57、.2.4whereinvolvedinthepipeandsteelstructureweldingwelders,welderbeforeentryexaminationsshouldattendtheowners,andconstructionshouldbemadewithinthescopeandeligibilityapprovedbythequalityandtechnologysupervisiondepartmentsandowners.6.2.5qualifyforweldingwelder,weldingprocess,shouldbeapprovedbyweldingth

58、eweldingprocess.己-將坐標(biāo)移至關(guān)找點(diǎn)主方向哪次羨轉(zhuǎn)再度后新生杼為二3 ： I cosfl -sin 3 | x，疝6 gs8 J yy)工旄幽像專桂區(qū)域內(nèi)對(duì)奉個(gè)通及蛋求其梯度幄役和方向，蜷后對(duì)每個(gè)株 展幅小來(lái)以昌有楨貴舞敦，生蠅方尚擊者用.uergijj =匐匕叫± jx.j i)| exp - k : R更與美逢裊為列Q& K ;行感與關(guān)蜒忠的行照奉j 0 - if, b (i-</L )x(1 - )a -等于揩生子貿(mào)工式9, m力圖比龍EM 的一半:instrument has a single test condition, will be tr

59、ansferred to the coordination of the test phase, the instrument according to the standalone trials scheduled, with the process preparation of test solutions, equipped with professional technicians and skilled workers, to ensure safety and quality. 6. welding engineering construction programme 6.1 this engineering used construction specification 6.1.1 s