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Data Mining & Knowledge Discovery. Mining association rules procedure to support on-line recommendation by customers and products fragmentation. S. Wesley Changchien, Tzu-Chuen Lu Expert Systems with Applications 20(2001) 325-335. 組員: M964020025 郭李哲 M964020027 鄭淵太
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Data Mining & Knowledge Discovery Mining association rules procedure to support on-line recommendation by customers and products fragmentation S. Wesley Changchien, Tzu-Chuen Lu Expert Systems with Applications 20(2001) 325-335 組員:M964020025 郭李哲 M964020027 鄭淵太 M964020044 鐘佶修
Background and motivation • Most of the EC business endeavor to survive and become leaders in the frontier of the new wave. • The major key factors of success include learning customers’ behavior of purchasing, developing marketing strategies to create new consuming market, and discover latent loyal customers, etc.
Rough set theory(RST) • 以RST進行資料分析全賴兩個基本觀念,稱之為集合的下界與上界近似(the lower and the upper approximations of a set)
Step 1- selection and sampling • 1. Creating a fact table • 2. Selecting dimensions • 挑選其所感興趣的dimension • 3. Selecting attributes • 根據重要性,挑選屬性 • 4. Filtering data • 限制屬性值的範圍
Step 2 - transformation and normalization • 1. 屬性為數值資料 • 2. 屬性為非數值資料 • 將資料做設計描述 • Job 屬性中的資料當作character
Step 3 – data mining of association rules • 採用neural network進行clustering與rough set theory 取得規則,以應用於找尋association rules,解釋每個cluster中其特性,和不同的cluster間屬性的關係。
Clustering module • Kohonen proposed SOM in 1980. • 顯示input屬性之間的natural relationship。 • We can group enterprise’s customers, products, and suppliers into clusters. • For instance, input nodes : education and job from the table member • Output nodes:nine clusters.
Rule extraction module • 使用Rough set theory 對資料記錄中同質的cluster找出association rules與不同cluster間其屬性間關係。
Characterization of each cluster • 利用Rough Set Theory來解釋一個cluster所擁有的特徵 • Ex:某類的顧客,其教育程度在大學以上、月薪3.5萬以上… • 產生Result equivalence classes, Xk • 產生Cause equivalence classes, Aij • 產生Lower approximation rules • 產生Upper approximation rules • 產生Combinatorial rules • 解釋cluster的特徵 • 重複(返回Step3)
step1.產生Result equivalence classes, Xk • 針對每個cluster產生result equivalence class
step2.產生Cause equivalence classes, Aij • 針對屬性產生Cause equivalence class
step3.產生Lower approximation rules • ,Confidence = 1 • X1 = { Member2, Member5, Member6} • = { Member2} • = { Member5, Member6} • = {Φ} • = {Φ} • = { Member2、Member5, Member6} • = {Φ} • Rule1: If Education = H then GID = A • Confidence = 1
step4.產生Upper approximation rules • , ,Confidence = • X1 = { Member2, Member5, Member6} • = { Member2} • = { Member5, Member6} • = {Φ} • = {Φ} • = { Member2、Member5, Member6} • = {Φ}
step4.產生Upper approximation rules • Confidence Threshold = 0.75 • Rule2: If Education = N then GID = A • Confidence= • Reject Rule2 (0.33≦0.75) • Rule3: If Job = H then GID = A • Confidence= • Accept Rule3(0.75 ≦0.75)
step5.產生Combinatorial rules • Confidence = • 結合Rule,產生考量多個屬性的關聯規則 X1 = { Member2, Member5, Member6}
step5.產生Combinatorial rules • Rule4: If Education = N and Job = H then GID = A • Confidence= • Rule5: If Education = H and Job = H then GID = A • Confidence =
step6.解釋cluster的特徵 • 將規則匯總並解釋其特徵 • 屬於Cluster 1(Cluster A)的Member: • 100%的人Education = High • 75%的人Job = High • 25%的人Education = Normal且Job = High • 50%的人Education = High且Job = High
step7.重複 • 返回Step3,計算下一個equivalence class Xk,以此方式重複進行直到所有的equivalence class皆計算完成。
Association of different clusters • 利用Rough Set Theory分析不同cluster之間的關係 • Ex: A類的會員較喜歡b類的商品;C類的會員較喜歡d類的商品…
Association of different clusters R3: If Buyer = 1 Then Receiver = 2, Confidence = 0.5 R4: If Buyer = 2 Then Receiver = 2, Confidence = 0.75 R1: If Product = 3 Then Receiver = 2, Confidence = 1 R2: If Product = 6 Then Receiver = 2, Confidence = 1 R5: If Product = 7 Then Receiver = 2, Confidence = 0.5
系統實做 • 以某家商店的交易紀錄為對象 • Product Table有1120筆記錄 • Customer Table有35筆紀錄 • 保留2000筆交易紀錄作為探勘的資料 • 經由維度、屬性的挑選 • Customer Clustering • education、job 、 gender • Product Clustering • sales price、import price 、 sale price of VIP customers
Use Rules for Recommendation • 某一位顧客想購買一個商品贈送其朋友,但他不知該買什麼較適合。 • 顧客的cluster = 7,而其朋友的cluster = 1,則系統可推薦cluster = 9之商品給顧客
Conclusion • 本篇採用SOM與rough set theory進行群集與規則粹取Rule extraction module描述了不同群集間之關係特性分析者可進一步選擇其他屬性,以分析出群集間的關係,例如,星座、心理測驗或血型等。 • 本研究利用Rough Set Theory找出資料中的關聯規則,而關聯規則又可分為兩個方向:cluster的特徵敘述和不同cluster間關係;然而在實作中,只有呈現不同cluster間之關係,並沒有提到cluster的特徵敘述和該如何應用。