PIF-COPRAS
PiF-COPRAS - COPRAS yönteminin Picture uzantısı
Picture üstünlük/sıralama - Resim Bulanık Küme (RBK: μ, η, ν; μ+η+ν ≤ 1)
Formül adımları
Analiz motorunun yöntem bildirimindeki (manifest F.steps) adımlar; raporlardaki formüllerle aynı kaynaktır.
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Adım 1 — Her DM'in H^(k) matrislerini PFWA ile grup PF karar matrisine birleştir (Lu 2021 Eş.14): h_ij = (1 − ∏_k (1−μ^k)^ψ_k, ∏_k η^k^ψ_k, ∏_k (ν^k+η^k)^ψ_k − ∏_k η^k^ψ_k). Tek DM varsa H = H^(1).
LaTeX
h_ij = (1 − ∏_{k=1}^l (1−μ_{ij}^k)^{ψ_k}, ∏_{k=1}^l (η_{ij}^k)^{ψ_k}, ∏_{k=1}^l (ν_{ij}^k + η_{ij}^k)^{ψ_k} − ∏_{k=1}^l (η_{ij}^k)^{ψ_k}) -
Adım 2 — CRITIC ile nesnel ağırlıklar q_j (Lu 2021 Eş.15-17): S(h_ij)=μ−ν, sütun-arası Pearson τ_jt, std σ_j, q_j = σ_j Σ_t(1−τ_jt) / Σ_j[σ_j Σ_t(1−τ_jt)].
LaTeX
τ_{jt} = Σ_i (S(h_{ij})-S̄_j)(S(h_{it})-S̄_t) / sqrt(Σ_i (S(h_{ij})-S̄_j)^2 · Σ_i (S(h_{it})-S̄_t)^2); σ_j = sqrt((1/m) Σ_i (S(h_{ij})-S̄_j)^2); q_j = σ_j Σ_t (1-τ_{jt}) / Σ_j [σ_j Σ_t (1-τ_{jt})] -
Adım 3 — Ağırlıklı normalleştirilmiş matris D (Lu 2021 Eş.18): d_ij = q_j × h_ij.
LaTeX
d_{ij} = q_j × h_{ij} = (1 − (1−μ_{ij})^{q_j}, η_{ij}^{q_j}, (ν_{ij}+η_{ij})^{q_j} − η_{ij}^{q_j}) -
Adım 4 — Fayda (max) için R_i^+, maliyet (min) için R_i^- (Lu 2021 Eş.19-20).
LaTeX
R_i^+ = ⊕_{j: max} d_{ij} = (1 − ∏_{j: max}(1−μ_{d_{ij}}), ∏_{j: max} η_{d_{ij}}, ∏_{j: max}(ν_{d_{ij}}+η_{d_{ij}}) − ∏_{j: max} η_{d_{ij}}); R_i^- analogous over cost attributes -
Adım 5 — Önem skoru O_i (Lu 2021 Eş.21).
LaTeX
O_i = S(R_i^+) + Σ_{k=1}^m S(R_k^-) / [S(R_i^-) · Σ_{k=1}^m (1/S(R_k^-))] -
Adım 6 — Fayda derecesi G_i = O_i / max O_k (Lu 2021 Eş.22).
LaTeX
G_i = O_i / max_{k=1,...,m} O_k (presented as G_i × 100%)
Yöntem ayrıntıları kaynak kütüphanedeki özgün (İngilizce) metindir.
Sezgi
Picture outranking/ranking - Picture Fuzzy Set (PiFS: μ, η, ν; μ+η+ν ≤ 1). Output typically utility (higher value = preferred).
Sonucu okuma: pif-copras extends COPRAS to handle Picture uncertainty. All arithmetic operations (normalisation, weighting, distance computation) are performed using Picture Fuzzy Set (PiFS: μ, η, ν; μ+η+ν ≤ 1) algebra. The final scores are defuzzified via score function S = μ − ν before ranking.
Varsayımlar
- Decision matrix entries are valid Picture Fuzzy numbers/tuples
- Underlying crisp method's compensation assumption holds in uncertain space
- All decision-maker(s) and experts use the same linguistic/uncertainty scale
Ne zaman kullanılmaz
- Classical data sufficient - use base COPRAS directly (avoid unnecessary uncertainty layer)
- Aggregation operator (PFWA/PFOWA/etc.) not specified - output ambiguous
Sınırlılıklar
- Rank reversal known on alternative-set changes (ref: Lu et al. 2021; cf. Belton-Gear 1983 for crisp COPRAS)
- Assumes: Decision matrix entries are valid Picture Fuzzy numbers/tuples
- Assumes: Underlying crisp method's compensation assumption holds in uncertain space
- Assumes: All decision-maker(s) and experts use the same linguistic/uncertainty scale
Sık yapılan hatalar
- Değer-uzayı ihlali: hesaplamadan önce tüm girişlerin PiFS: μ (membership), η (neutral), ν (non-membership); μ+η+ν ≤ 1 koşulunu sağladığından emin olun.
- Defuzzifikasyon yöntemi sıralamayı etkiler: score function S = μ − ν kanonik seçimdir.
Hesap adımları ve dayanakları
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Aggregate per-DM matrices H^(k) (k=1,...,l) into group PF decision matrix H = [h_ij] via PFWA (Lu 2021 Eq.14): h_ij = (1 − ∏_k (1−μ^k)^ψ_k, ∏_k η^k^ψ_k, ∏_k (ν^k+η^k)^ψ_k − ∏_k η^k^ψ_k), where ψ_k is the expert weight (Σψ_k = 1). If only a single DM is provided, H = H^(1).
Dayanak: Lu 2021 Eqs.12-14; Wang 2017 PFWA
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Determine objective criteria weights q_j via CRITIC (Lu 2021 Eqs.15-17) using score S(h_ij) = μ − ν. Compute Pearson correlation τ_jt between columns; standard deviation σ_j; then q_j = σ_j Σ_t (1−τ_jt) / Σ_j [σ_j Σ_t (1−τ_jt)].
Dayanak: Lu 2021 Eqs.15-17; Diakoulaki et al. 1995 (CRITIC origin)
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Weighted normalized matrix D = [d_ij] via scalar multiplication (Lu 2021 Eq.18; Wang 2017 scalar-mult Eq.4): d_ij = q_j × h_ij = (1−(1−μ)^{q_j}, η^{q_j}, (ν+η)^{q_j} − η^{q_j}).
Dayanak: Lu 2021 Eq.18; Wang 2017 Eq.4 (scalar mult)
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Sum weighted PFNs over benefit (max-direction) attributes → R_i^+, and over cost (min-direction) attributes → R_i^- via Wang 2017 ⊕ (Lu 2021 Eqs.19-20): R_i = (1−∏(1−μ_d), ∏η_d, ∏(ν_d+η_d)−∏η_d).
Dayanak: Lu 2021 Eqs.19-20; Wang 2017 Eq.2 (⊕)
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Significance O_i (Lu 2021 Eq.21): O_i = S(R_i^+) + Σ_k S(R_k^-) / [S(R_i^-) · Σ_k 1/S(R_k^-)], where S(α)=μ−ν (Cuong 2014 Def.3, Eq.6).
Dayanak: Lu 2021 Eq.21
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Utility degree G_i = O_i / max_k O_k (Lu 2021 Eq.22; reported as percent). Higher G_i ⇒ better. Rank alternatives by descending G_i.
Dayanak: Lu 2021 Eq.22