ON INFORMATION MATRI CES OF FRA(1’10NAL 2m FACrORIAL
DESIGNS DBRIVED FROM BALANCED ARRAYS
Sumiyasu YAMAMDTO and Yoshifumi HYODO (Received Nove㎡)er 5,1984) 1.Introduction and summary. The purpose of this paper is to give an explicit expression of the ele二 『 ments of irreducible representation of the infomation matrix derived fr㎝a’ two−s)mbol balanced array of even strength in tems of its paralneters. The results obtained here are generalizat ion of formilas given by shirakura and KUwada [2】. The reader should refer to Yamamoto, Shira㎞ra and KUwada [3,4], and Shira㎞ra and血wada[2]fOr details as well as definitions. C・n・id・r a f・a・・i・皿・評fac・・ri・・〔Pm−FF〕d・・igu・i・h・fact…FpF2, … ,Fm, each at two levels O or 1. Assume that (兄+1)−factor and higher order intera・ti・n・are negligib1・f・r an i・t・ger見・m/2・Th・・見・1 param・t・・vec− tor 自L of factorial effects up to 兄一factor interactions considered here is 〔1〕 Q’ ’(θφ;{θt、};{θt、・、};’”・{θt、・2…・、}〕 砲ere…Σ{・・Φ・・nd・φ・・t、 an・・・…nera・…、・、…・k d・n…th・g・n・ra・ mean・the main effect°f thg fact°「Ft、 and the k−fact°「inte「act’°n°f the fact°「s’Ft、・Ft、・’”・F・k・「espect’vely[3】・@ ・.
Let T be a戸一FF design c㎝posed of N ass㎝blies or treatment combina− tions, then T can be expressed as a two−s)nnbol array of size N x m whose rows den°te asseゆ1ies・The e・rPect・ti・n・f th・・b・ervati・n vect・r断㎝d th・ i・f・m・・i・h・…i・Mr f・r e・ti・・ti・g旦・f・h・2m−FF d・・ig・T・re give・by(2) E(MT)=ETQ
and
叫=E拝T・
where ET is called the design matrix [3】・
334 S.YA脚K〕TO AND Y.}{YODO Among those factorial effects, a triangular type multidimensional par− tially balanced 〔TMDPB ) association scheme is introduced naturally in・away such thatθt、…tu andβ・i…・↓a「e theα一th ass°c’ates if and°nly’f (3〕 1{t・・…・t。}・{ti・’”・t↓}1=mi輌・・)一・・ It is knowr1[3]that a㎜PB association algebra A generated by those (剛〔2・・〕(・2・3〕/6・・t・・ce・D!u・v)(・,…,・,…,・・…,・,…,…(・,・)) representing the above relations of association is semi−s迦ple and c㎝pletely
蕊il;e;、:1盧;1晋?都1°、1;1.t買lll鷲all。iββ9:nllll鷲.
Now consider the case where the design T is given by a two−symbol ba1− ・nced・・ray〔B−array〕・f・trength 22・m・…traint・a・d i・d・x・et{Ve・μ1・ …・μ2£}・Th・i・f{・・M・ti・n m・t培・f・u・h d・・ign i・giv・n in[4]・i・… (・〕 1・Zr =・1。。Σ{二1・;二1・;・j・1β+’・β+j)#・where
(・) ・;・」・・1・’一・::;・j.i.、。・19+’・β+j〕 for O ≦ i ≦ 」 ≦ 2一β and β = 0,1,.●.,2. Here Yi d・n・t・・the e1・m・nt・f MT・…e・p・ndi・g t・th・p・i・・f・ffect・ θt、…・uandθti…・↓ satisfyi”g 〔6〕 1{tP…・t。}・{ti・”・・t↓}1・i・ for i = 0,1,・●・,22, and 〔・) ・1:+’・β÷j)・Σ9.。〔一・)α≡b(;)(1‡1:2)(m−26−’+b) in、 (8〕 〔9) The [3], ・{(m吉i)〔」1、〕}1/2/(」一;+b)・ f・11・wi・g・。nnecti・n b・tween these yi and the i”dices Pj can be seen i.e., ・、・ l三。Σ1.。(一・〕P〔;)(1↓:圭,)Uj・ ・、・{考&。ΣB。。〔一・〕P〔jl,)〔2㌃’)・j・/22見・…,・,…,・・. 、m INFORト・酊ICN MATRICES OF 2 −FF DESIGNS The given by 〔10〕 i「「educible「ep「esentati°n°f Mr with「espect t・each idea1 Aβi・ K,3= 0,0 κβ 1,0 κβ … k一β,O Kβ
and its㎜1tiplicity isφ
0,l Kβ ◆” 1,1 Kβ ● ● ● … ・;一β・1… β一〔:)一 O,2一βKB
1,A,−B Kβ … ・き一β・丸≡β 〔mタ一1)・ ] P⊆k) isg初θη勿 〕 〔・・〕・}k〕・Σi三。〔告k)・、允・」・・………….・、卿{k)卿・一・・・・…働…
(・2)・、・・}.。Σ;.。〔一・〕P〔;〕〔」81},)・lk〕・ 〔・3)・{k)・{・;。。Σ;。。(一・〕P〔j㌔)〔k;’)・j}/・k・・ Le㎜a 2.㌘カθfoZZo痂9碗η力坑θsわZ∂(see, e.9.,Shira㎞ra and Kumada[2D.
(・4) ・;.。(一・〕Pζ〕〔、£,〕・〔一・)α(:)・ (・5〕 ・害。。(一・)P(;〕〔、諾.P〕… (・6) ・;.。〔1:;〕〔;)・(1〕・ 2. Explicit expression of irreducible representation. An e)甲1icit expression of the elements of irreducible representation of th・inf。rm・ti・n m・t・i・)片 i・t・m・・f i・dices VO・V1・…・μ2k and m・f th・B− array used・may・b・u・eful in i・vestig・ti・g th・・tructu…f・2m−FF design. For such purpose, it is sufficient to substitute (7〕 and 〔8〕 into 〔5〕. The expression obtained in such a way, however, very complicated. So, some reduc− tion is necessary. The following results and identities are usefUI for such purpose・。_跳1’、㌶∵;㍑1。1㌔留ご::。麗。嘘㌶1。城
= 0,1,… ,k. Riordan [1] and336 S.YAMAMOTO AND Y. HYODO 〔・7)・:.。Σ;;。〔一・)P+α〔C〕〔」鵠)(9)・22ω・j。・
励…(a
ajd・屹・th・屍・・㌦…∬励励励〔言)・時唖・鳩iアb・・
°㌘0≦a<b・and 6
潟ヨ=1・”O・・…鋤・・j;…j≠ω・
Theorem 1・ Th・e e zements K;’〕 oτthe iPre〈luciわzε rep?esentαtion KB o王Mh apθ 穿iveη わz4 > ) ・;・j・[・;.。Σ嵩」一’〔一・〕「(;〕〔m㌣b〕{〔m君’〕({〕}1/2(2bζ一’) 〔、8〕 ・〔;{;〔1翻)22〔β+’−b〕/〔j’;+b〕]・兄 ・・1.、[・;.。Σi;6j−’(一・)「〔;〕(m−2宥’+b〕・〔m吉’)({〕}’/2(2b㌢一’〕 ・〔 2£一〔2β+i+j)£+r+s−〔B+」+b)〕22(β+’≡b〕/(j−;+b)]・・、.,・(一・)」一’・、.s・, ∫ヒ)1。 0≦i≦j≦見一β , β=0,1,・..,兄. Proof. If β+i+j ; O or β=i=j=0, we have ・;・°・・。・〔222〕・、・Σ1.、〔窟、)(・、.s・・、−s) by substituting 〔7) and (8〕 into 〔5〕. The formula 〔18) holds in this case. We sha11, therefore, assume that B+i+」 > 0. Substituting (7) into.(5〕 we have 〔、9〕・;’」・Σ;・・(一・・b〔;)〔m−2㌻’+b)・〔m君’)({〕}1/2 …爵(一・)α〔βご;b〕・、。.j.i}/〔j−;+b)・ Since l ≦ 2β+i+j ≦ 22, using (12) we can express the term in { } of (19) as: ・::;〔一・〕α〔B㍍b〕・、。.」.i 〔・・〕・Σ蓋皇;’+j・・皇:;・lg;」一’(一・〕α+P〔2α3−’)〔、:巳碧轟,) ・〔B;IBb〕}・舌2β+’+j). ⑳ The c。・ffi・ient・f 1・i[2β+’+j)i・(・・)can be s迦・・if・・d by・・i・,(・4),(・5〕, 〔16) and, especially 〔17〕 as follows:m −FF DESIGNS INFORMATION MATRICES OF 2 ・…:;・1二6j”〔一・)α+P〔2αζ一’〕〔、鵠臨〕(βご;b) ・・iR6j−’〔2b⊇一’){・::;・lg6j−’C・)α+P(2ぽ〕〕 ・〔 2〔β+i〕一・ 2Cth−〔j−i〕−2〔x+P〕(β㍍b〕} 〔、、〕・Σそ;」一’〔2bζ一’)唱㌔劉2b+〔j−’)一「(一・)°「’P+「+b〔r・ ・〔 2(β+i−b)−2αh+r−2b−〔j−i)−2Ct十p〕(β+:−b)} ・(一・〕b・i三6j−’〔一・〕「(2b亨一’〕{・::;−b・1:。〔一・〕α+P〔C〕 ・(、.r:{1士1;;鵠。.P〕(β+ま一b)} ・(一・)b・;∵δj−’〔一・)「〔2bζ一’)22(β+’−b)・h〔,.」.b.r〕・ Hence, from (20〕 and (21) we have ・::;〔一・)°「(β誌b〕・、。.j.i 〔22) ・〔一・)b・1≧6j−’(一・〕「〔2bζ一’〕22〔β+’≡b)pl三!:gtl〕・ Thus 〔19〕 may be simplified as ・;・j一Σ;。。〔;〕〔m−2㌻’+b〕{〔噴’)〔{〕}1/222〔β+’−b) (23〕 @…i?6j−’〔一・)・〔2b?一’・・i三!:已)}/(j”9“b・・ Us ing 〔11) and the identities ・1二;・9;」”(一・)「(2b?一’〕認鵠)・s ・〔一・)j−’Σ1.、Σi26j−’〔一・〕「〔2bζ一’〕(、三慧;…;{∼))U、.s・ ・i&、.、Σ三6j−’〔一・〕「〔2bζ一’〕〔i鵠‡}:91〕・s ・Σ1.、Σi2;j−’(一・〕「(2btj−’〕(、三欝;認))・、.s・ s
338 S.YAMAMOTO AND Y. HYODO we have ’・…;;j−’〔一・〕「〔2bζ一’〕・1三!:已〕 〔・4〕・Σ…26j−’(一・)「〔2b?一’)(kg2,g‡}瑠〕・兄 ・Σ:.、{・i?6j”(一・〕「(2bζ一’〕〔、i:;!i%i;・lg,)}{・、.,+(一・〕j”u、.s}・ Substituting 〔24) into 〔23) we have 〔18). This completes the proof・ Remark: If j−i is odd, since we have ・iヒ;j”(一・〕「(2b?一’〕(;聡‡}詔〕… the coefficient of P2 in Theorem l vanishes・ We・therefore, obtain the following : (・〕・fj−iisev・n・・;’コi・afm・ti・n・f・、.s・・、−s・ s=0,1,◆.●,見一β. (b〕・fj−ii・・dd・・;’コi・a血nc・i…f・、.s−1・、.s・ s=1,2,… ,∫↓一β. Example 1. Let T be a 2m−FF design derived fr㎝aB−array of strength 4〔k=2〕・m・。・・t・aint・and i・dices pO・P1・U2・P3・P4・th・n w・have ・1・°・(1.1。・・、)・4(・、・・3)・6・、, ・1・1・・1/2{(V、一・。〕・・(・3−1.L、〕}, ・;・2−{・(m−・)/・}’/2{(・。・・4〕−2・、}, ・;・1・・(V。・・、)・4〔・、・・3〕−2(m−・)・、, ・;・2・{〔m−・)/・}1/2{・(・4−・。)−2(・一・)(・3一μ、)}・ ・;・2・{・⑭/・}〔・。・・4〕−2(m−4)(m−・)(・、・・,〕 ・{3〔m−4〕2・5(m−4)・4}・、, ‘
6〔 INFORト{ATION MATRI〔ES OF 2m−FF DESIGNS ・1・°・4{〔1.t、・1.1,〕…、}, ・1・1・4(m−2)1/2〔・3−・、〕, ・{・1−4{(rn−2)〔・、・・3)−2〔・−4)・、},・・d ・;・°・・6・、. Example 2. Let T be a 2m−FF design derived from a B−array of strength 2=3〕・皿・・n・trai・ts and indi−Ces UO・pl・μ2・P3・μ4・μ5・P6・Th・n we have ・;・°一〔・。・・6)・6〔P、・・,〕・・5(・、・・4〕・・Or,, ・8・1・m1/2{〔・6−・。)・4(・5−・、〕・・〔・4−・、)}, ・8・2・{・〔m−・〕/・}1/2{〔V。・1.1、〕・・(U、・・、)一〔・、・・4〕一 ・;・3・{・(m−・〕〔m−2)/・}1/2{(・6−U。)一・〔・4−・、)}, ・;・1・m(・。・・6)・・(…〕(・、・U、〕一〔m−・6〕(・、・・、)一 = 2 ,
10
K = 3 ,10
K = 2 ,20
K = 3 ,20
K = 3 , 7﹂O K 4U3}・ 4(m←6〕μ3・ {〔m−・)/・}1/2{・〔・6−・。〕・8〔・5−V、〕一(3m−・6)〔・4−・、)}, {(m−・〕(m−2〕/・}1/2{・(U。・・6)−2〔m−6〕(・、・1.1、〕一・〔・、・・、〕+4〔m−6〕V3}・ . tt
{m(m−1〕/2}〔pO+P6)一〔m−1〕(m−8)(μ1+μ5〕 一[{〔m−6)2…(m−6)−2}/・]〔・、・・4〕 ・2{(mT・)2・・〔m−6〕・6}・3, {〔m−2)/・・}1/2[・〔m−・)(・6−・。〕−4(m−・〕(m−6)(V5−・、) ・{・(・−6)2・・〔・−6)・6}(・4−V、〕], {m(m−1)(m−2〕/6}(pO “ V6〕一(m−6)(m−2)〔m−1)〔P1+V5〕 ・[〔・−2〕{・(m−6)2・・(m−6〕・6}/・](1.L、・・、) 一[・〔m−6){・(m−6)2・2・〔m−6)・28}/・]・3,340 S.YAMAMOTO AND Y. HYODO 0,0 K1 0,1 K1 0,2 Kl 1,1 Kl 1,2