Nghiên cứu các cách tiếp cận trong tóm tắt văn bản và thử nghiệm

BỘ GIÁO DỤC VÀ ĐÀO TẠO TRƯỜNG ĐẠI HỌC BÁCH KHOA HÀ NỘI - LUẬN VĂN THẠC SĨ KHOA HỌC NGHIÊN CỨU CÁC CÁCH TIẾP CẬN TRONG TÓM TẮT VĂN BẢN VÀ THỬ NGHIỆM NGÀNH: CÔNG NGHỆ THÔNG TIN Mà SỐ:3.04.3898 SAM CHANRATHANY Người hướng dẫn khoa học: TS LÊ THANH HƯƠNG HÀ NỘI - 2008 LỜI CAM ĐOAN Tôi – SAM CHANRATHANY Học viên lớp Cao học CNTT 2005-2007 Trường Đại học Bách Khoa Hà Nội – cam kết công trình nghiên cứu thân hướng dẫn TS LÊ THANH HƯƠNG Bộ môn HỆ THỐNG THÔNG TIN – Khoa CNTT – Trường Đại học Bách Khoa Hà Nội.Các kết nêu luận văn trung thực, không chép toàn văn công trình khác Hà Nội, tháng 04 năm 2008 SAM CHANRATHANY Lời Cảm Ơn Trước hết xin gửi lời cảm ơn đặc biệt tới TS.Lê Thanh Hương, Bộ môn Hệ Thống Thông Tin, Khoa Công Nghệ Thông Tin, Trường Đại Học Bách khoa Hà Nội, Người định hướng đề tài tận tình hướng dẫn báo suốt trình thực luận văn cao học Tôi xin gừi lời cảm ơn sâu sắc tới Trung Tâm Đào Tạo Sau Đại Học thầy cô giáo Khoa Công Nghệ Thông Tin, Trường Đại học Bách Khoa Hà Nội tận tình giảng dậy truyền đạt kiến thức, kinh nghiệm quý báu suốt năm học Cao Học Cuối xin bày tỏ lòng cảm ơn chân thành tới tất bạn bè, thầy cô giáo, bạn khoa nghệ thông tin 2005-2007, trường đại học Bách khoa Hà Nội động viên, tạo điều kiện cho suốt thời gian thực luận văn Hà Nội, tháng 04 năm 2008 Sam chanrathany MỤC LỤC Trang LỜI CẢM ƠN LỜI CAM ĐOAN Mục Lục……………………………………………………………… Danh Mục Từ Viết Tắt……………………………………………… Danh Mục Bảng …………………………………………………… Danh Mục Hình Vẽ………………………………………………… Mở Đầu……………………………………………………………… CHƯƠNG TỔNG QUAN VỀ TÓM TẮT VĂN BẢN 1.1 khái niệm tóm tắt văn ……………………………………… 10 1.2.phân loại toán tóm tắt văn bản……………………………… 11 1.2.1 Phân loại theo đầu vào………………………………………… 11 1.2.1.1 Dựa nguồn……………………………………………… 11 1.2.1.2.Dựa Trên Ngôn Ngữ ………………………………………… 12 1.2.2.Phân Loại Theo Mục Đích …………………………………… 13 1.2.2.1.Dựa cách sử dụng……………………………………… 13 1.2.2.2.Dựa Trên mục đích tóm tắt ………………………………… 13 1.2.3.Phân Loại Theo Đầu ……………………………………… 14 1.2.3.1 Kiểu tóm tắt………………………………………………… 14 1.2.3.2.Ứng dụng Desktop ứng dụng Web…………… 15 1.2.4.Phân Loại theo kỹ thuật……………………………………… 15 1.2.4.1.Hướng tiếp cận cô điển…………………………………… 15 1.2.4.2.Hướng tiếp cận dựa tập ngữ liệu Corpus……………… 16 1.2.4.3.Hướng tiếp cận dựa tri thức…………………………… 17 1.2.4.4.Hướng tiếp cận khai thác cấu trúc ngôn ngữ………………… 17 1.3.Các chi tiểu đánh giá………………………………………… 18 1.4 Hệ thống tóm tắt văn điển hình…………………………… 19 CHƯƠNG 2.CÁC PHƯƠNG PHÁP ĐÁNH GIÁ TÓM TẮT VĂN BẢN 2.1.Giới thiệu………………………………………………………… 22 2.2 Đánh giá bên trong………………………………………… 24 2.2.1 Tính mạch lạc tóm tắt ……………………………… 24 2.2.2 Độ hàm chứa thông tin tóm tắt ……………………… 25 2.2.3.Độ xác độ hồi tưởng…………………………… 25 2.2.4.Phương pháp xếp hạng câu……………………………… 27 2.2.5 Phương pháp Lợi ích liên quan…………………………… 27 2.2.6.Mức độ giống nội dung ………………………… 28 2.3 Đánh giá bên ngoài………………………………………… 29 2.3.1 Đánh giá độ phù hợp………………………………… 29 2.3.2.Đánh giá độ đọc hiểu………………………………… 31 2.4 So sánh hai phương pháp ……………………………………… 31 2.5 Hệ thống đánh giá có sẵn này……………………………… 32 2.5.1 MEADeval…………………………………………………… 32 2.5.2 ROUGE……………………………………………………… 33 CHƯƠNG 3.CÁC PHƯƠNG PHÁP DÙNG TRONG TÓM TẮT VĂN BẢN 3.1 Qúa trình tóm tắt văn bản……………………………………… 40 3.1.1 Bước Xác định chủ đề ……………………………………… 42 3.1.2.Bước Biến đổi ……………………………………… 42 3.1.3 Bước Hiển Thị ……………………………………… 43 3.2.Các phương pháp dùng bước tóm tắt………………… 44 3.2.1.Phương pháp xác định chủ đề ………………………………… 44 3.2.1.1 Phương Pháp dựa vị trí………………………………… 44 3.2.1.2 Phương Pháp dựa từ gợi ý ……………………………… 45 3.2.1.3 Phương Pháp dựa tần số xuất thuận ngữ……… 46 3.2.1.4 Phương Pháp chống lấp tiêu đề câu truy vấn…………… 47 3.2.1.5 Phương Pháp mối quan hệ từ vựng ………………………… 47 3.2.1.6 Phương Pháp cấu trúc diễn ngôn…………………………… 52 3.2.1.7 Lập luận dựa sở tri thức…………………………… 53 3.2.1.9 Phương Pháp Phù Hợp Biên MMR………………………… 54 3.2.1.10.Phương pháp Ngữ nghĩa tiềm ẩn LSA……………………… 55 3.2.1.10.Trích rút thông tin ……………………………………… 55 3.2.2.Quá trình biến đổi ……………………………………… 57 3.2.2.1.Giản lược cấu trúc câu………………………………… 57 3.2.2.2.Giản lược mặt ngữ nghĩa ……………………………… 58 3.3.Hiển thị……………………………………… 59 3.3.1 Phương pháp hiển thị phân đoạn ……………………………… 60 3.3.2.Phương pháp Hiển thị liên kết………………………………… 61 3.3.3.So sánh phương pháp……………………………………… 61 CHƯƠNG THỬ NGHIỆM VÀ ĐÁNH GIÁ HỆ THỐNG 4.1 Các hệ thống dùng để so sánh…………………………………… 63 4.2 Quý trình kiểm tra…………… ………………………………… 71 4.3 Kết thu được….……………………………………… 72 4.3.1.Văn tham khảo hệ thống Mead 72 4.3.1.2.Đánh giá mức độ trích chọn chung………………………… 72 4.3.1.2.Đánh giá mức độ giống nội dung…………………… 73 4.3.2.Văn SUM-TREE-BANK………………………………… 76 4.4.NHẬN XÉT CHUNG………………………………………… 78 TÀI LIỆU THAM KHẢO…………………………………………… 82 PHỤ LỤC …………………………………………………………… 87 DANH MỤC CHỮ VIẾT TẮT Chữ viết tắt Tiếng Anh Tiếng Việt DUC Document Understanding Hội nghị hiểu văn Conference LCS Longest common subsequence Dãy chung dài LSA Latent Sematic Analysis Phân tích ngữ nghĩa tiềm ẩn MMR Maximal Marginal Relevance Phù hợp biên tối đa WLCS Weighted Longest common Dãy chung dài dựa subsequence trọng số RUM Relative Utility Method Phương pháp lợi ích liên quan RST Rhetorical Structure Theory Lý thuyết cấu trúc diễn ngôn SVD Singular Value Decomposition Phân tách giá trị đơn TF Term Frequency Tần số xuất thuận ngữ TF-IDF Term Frequency-inverse Tân số kết hợp tf idf document frequency DANH MỤC BẢNG Trang Hình 2-1 Bảng kết đánh giá tóm tắt ROUGE 39 Hình 4-4 Bảng mức độ trích chọn chung dựa độ 73 xác độ hồi tưởng Hình 4-5 Bảng trung bình cộng mức độ trích chọn chung 73 dựa độ xác độ hồi tưởng Hình 4-6 Bảng trung bình cộng mức độ trích chọn chung 74 dựa Kappa Hình 4-7 Bảng mức độ giống nội dung cosin 75 văn Hình 4-8 Bảng trung bình cộng mức độ giống nội 75 dung Cosin Hình 4-9 Bảng trung bình cộng mức độ giống nội 76 dung dựa đơn vị trung lặp Hình 4-11 Bảng trung bình cộng mức độ giống nội 77 dung Cosin so với Abstract DANH MỤC HÌNH Trang Hình 3-1 Mô hình chung tóm tắt văn 41 Hình 3-2 Mô hình chung trích rút văn 41 Hình 3-3 Hệ thống tóm tắt dựa mối quan hệ từ vựng 46 Hình 3-4 Văn dùng để tìm mối quan hệ từ vựng 48 Hình 3-5 Biểu đồ quan hệ từ vựng cho LC3 52 Hình 3-6 Biểu đồ cấu trúc diễn ngôn 53 Hình 4-1 Mô hình hệ thống tóm tắt Swesum 66 Hình 4-2 Giao diện Swesum 67 Hình 4-3 Giao diện đồ hoạ hệ thống Mead 69 97 But the ad also mentions Sears's sales a topic that the retailer has avoided since switching to everyday pricing "When Sears has a sale at a special price," the woman in the ad declares, "it's something you don't want to miss." Recent surveys by Leo J Shapiro & Associates, a market research firm in Chicago, suggest that Sears is having a tough time attracting shoppers because it hasn't yet done enough to improve service or its selection of merchandise The number of people who said they were more likely to shop at Sears fell in September to 37% from 66% in March, when Sears blanketed the airwaves with ads about its new pricing strategy Moreover, the number of people who spontaneously cited lower prices as the reason for their interest in Sears declined to 16% in September from 33% in March Just 5% of the respondents mentioned brands in September, up slightly from 2% in March Only 2% of the people in September cited Sears's "friendly personnel." "The power of price as an appeal, which was very considerable in driving traffic in March and April, has diminished," says George Rosenbaum, president of Shapiro & Associates "You see some improvement in these other areas, but it's a very small and slow process." For the third quarter, Sears said its total revenue rose 4.8% to $13.18 billion from $12.57 billion a year earlier Net income at Sears's merchandise group, which includes international and credit card operations, as well as U.S stores, fell 25% Profit at Sears's Allstate insurance unit fell 38% to $126.1 million because of Hurricane Hugo, which inflicted the greatest single storm damage loss in the company's history Sears said claims from the storm, as expected, reduced its third-quarter net by $80 million, or23 cents a share Allstate is expected to absorb another big hit in the fourth quarter as claims pour in from the San Francisco earthquake But a spokesman said the quake won't have as big a financial impact on Allstate as Hurricane Hugo did Net income at Sears's Dean Witter Financials Services group, meanwhile, rose nearly 32% to $35.7 million, reflecting improvements in its basic stock brokerage and Discover credit card businesses Profit at Sears's Coldwell Banker Real Estate Group nearly quadrupled to $81.2 million because of gains on sales of property In New York Stock Exchange composite trading yesterday, Sears shares closed at $40.50, up 87.5 cents 98 PHỤ LỤC B B CÁC KẾT QUẢ THÍ NGIỆM TRÊN CÁC HỆ THỐNG VĂN BẢN THAM KHẢO MEAD MEAD VB1 PT CẦU CHỌN 10% CAIRO Egypt The crash of a Gulf Air flight that killed 143 people in Bahrain is a disturbing deja vu for Egyptians: It is the second plane crash within a year to devastate this Arab country.Sixty-three Egyptians were on board the Airbus A320 which crashed into shallow Persian Gulf waters Wednesday night after circling and trying to land in Bahrain Many of the passengers on the Gulf Air flight were headed for jobs in Bahrain or elsewhere 20% CAIRO Egypt The crash of a Gulf Air flight that killed 143 people in Bahrain is a disturbing deja vu for Egyptians: It is the second plane crash within a year to devastate this Arab country Sixty-three Egyptians were on board the Airbus A320 which crashed into shallow Persian Gulf waters Wednesday night after circling and trying to land in Bahrain On Oct 31 1999 a plane carrying 217 mostly Egyptian passengers crashed into the Atlantic Ocean off Massachusetts Many of the passengers on the Gulf Air flight were headed for jobs in Bahrain or elsewhere in the Gulf In the hours just after the crash relatives at the Cairo airport expressed anger and frustration at Gulf Air for the slow release of information Egypt which lacks the oil wealth of the Gulf and has an economy struggling to revive from decades of socialist stagnation has a long tradition of sending workers to the Gulf to fill everything from skilled to menial jobs 30% CAIRO Egypt The crash of a Gulf Air flight that killed 143 people in Bahrain is a disturbing 99 deja vu for Egyptians: It is the second plane crash within a year to devastate this Arab country Sixty-three Egyptians were on board the Airbus A320 which crashed into shallow Persian Gulf waters Wednesday night after circling and trying to land in Bahrain On Oct 31 1999 a plane carrying 217 mostly Egyptian passengers crashed into the Atlantic Ocean off Massachusetts Walid Mourad head of the Egyptian Pilots Association and a voice often heard in relation to the EgyptAir investigation said Wednesday's crash is a tragedy for the Arab people as a whole Many of the passengers on the Gulf Air flight were headed for jobs in Bahrain or elsewhere in the Gulf In the hours just after the crash relatives at the Cairo airport expressed anger and frustration at Gulf Air for the slow release of information In Bahrain relatives were beginning the wrenching process of identifying the victims from photographs taken after the bodies were retrieved from the Gulf Egypt which lacks the oil wealth of the Gulf and has an economy struggling to revive from decades of socialist stagnation has a long tradition of sending workers to the Gulf to fill everything from skilled to menial jobs 40% CAIRO Egypt The crash of a Gulf Air flight that killed 143 people in Bahrain is a disturbing deja vu for Egyptians: It is the second plane crash within a year to devastate this Arab country Sixty-three Egyptians were on board the Airbus A320 which crashed into shallow Persian Gulf waters Wednesday night after circling and trying to land in Bahrain On Oct 31 1999 a plane carrying 217 mostly Egyptian passengers crashed into the Atlantic Ocean off Massachusetts 100 Walid Mourad head of the Egyptian Pilots Association and a voice often heard in relation to the EgyptAir investigation said Wednesday's crash is a tragedy for the Arab people as a whole Many of the passengers on the Gulf Air flight were headed for jobs in Bahrain or elsewhere in the Gulf Hassan worked in a restaurant in Bahrain his uncle said before disappearing into a room at the airport set aside for relatives desperate for news In the hours just after the crash relatives at the Cairo airport expressed anger and frustration at Gulf Air for the slow release of information Gulf Air said it was sending a special plane to carry 134 relatives to Manama airport later Thursday All necessary measures have been taken to receive the families of the victims Mohammed al-Sayed Abbas the Egyptian ambassador to Bahrain told Egyptian television In Bahrain relatives were beginning the wrenching process of identifying the victims from photographs taken after the bodies were retrieved from the Gulf Egypt which lacks the oil wealth of the Gulf and has an economy struggling to revive from decades of socialist stagnation has a long tradition of sending workers to the Gulf to fill everything from skilled to menial jobs AUTOSUMM VB2 PT 10% [1].CAIRO, Egypt The crash of a Gulf Air flight that killed 143 people in Bahrain is a disturbing deja vu for Egyptians: It is the second plane crash within a year to devastate this Arab country [10].Many of the passengers on the Gulf Air flight were headed for jobs in Bahrain or 101 elsewhere in the Gulf [11].Rida Hassan was one of those escaping Egypt's moribund economy for work in the oil-rich Gulf 20% [1]CAIRO, Egypt The crash of a Gulf Air flight that killed 143 people in Bahrain is a disturbing deja vu for Egyptians: It is the second plane crash within a year to devastate this Arab country [3]On Oct 31, 1999, a plane carrying 217 mostly Egyptian passengers crashed into the Atlantic Ocean off Massachusetts [10]Many of the passengers on the Gulf Air flight were headed for jobs in Bahrain or elsewhere in the Gulf [11]Rida Hassan was one of those escaping Egypt's moribund economy for work in the oil-rich Gulf [18]Absolutely nothing," Mohammed Ibrahim elNaggar said hours after the crash [21]Gulf Air said it was sending a special plane to carry 134 relatives to Manama airport later Thursday 30% [1]CAIRO, Egypt The crash of a Gulf Air flight that killed 143 people in Bahrain is a disturbing deja vu for Egyptians: It is the second plane crash within a year to devastate this Arab country [2]Sixty-three Egyptians were on board the Airbus A320, which crashed into shallow Persian Gulf waters Wednesday night after circling and trying to land in Bahrain [3]On Oct 31, 1999, a plane carrying 217 mostly Egyptian passengers crashed into the Atlantic Ocean off Massachusetts [10]Many of the passengers on the Gulf Air flight were headed for jobs in Bahrain or elsewhere in the Gulf [11]Rida Hassan was one of those escaping Egypt's moribund economy for work in the oil-rich Gulf [18]Absolutely nothing," Mohammed Ibrahim elNaggar said hours after the crash [21]Gulf Air said it was sending a special plane 102 to carry 134 relatives to Manama airport later Thursday [26]Remittances from citizens working abroad make up Egypt's biggest source of foreign exchange 40% [1]CAIRO, Egypt The crash of a Gulf Air flight that killed 143 people in Bahrain is a disturbing deja vu for Egyptians: It is the second plane crash within a year to devastate this Arab country [2]Sixty-three Egyptians were on board the Airbus A320, which crashed into shallow Persian Gulf waters Wednesday night after circling and trying to land in Bahrain [3]On Oct 31, 1999, a plane carrying 217 mostly Egyptian passengers crashed into the Atlantic Ocean off Massachusetts [10]Many of the passengers on the Gulf Air flight were headed for jobs in Bahrain or elsewhere in the Gulf [11]Rida Hassan was one of those escaping Egypt's moribund economy for work in the oil-rich Gulf [12]Hassan worked in a restaurant in Bahrain, his uncle said before disappearing into a room at the airport set aside for relatives desperate for news [15]In the hours just after the crash, relatives at the Cairo airport expressed anger and frustration at Gulf Air for the slow release of information [18]Absolutely nothing," Mohammed Ibrahim elNaggar said hours after the crash [21]Gulf Air said it was sending a special plane to carry 134 relatives to Manama airport later Thursday [22]"All necessary measures have been taken to receive the families of the victims," Mohammed al-Sayed Abbas, the Egyptian ambassador to Bahrain, told Egyptian television [26]Remittances from citizens working abroad make up Egypt's biggest source of foreign exchange 103 SWESUMM VB1 PT 10% [1].CAIRO, Egypt The crash of a Gulf Air flight that killed 143 people in Bahrain is a disturbing deja vu for Egyptians: It is the second plane crash within a year to devastate this Arab country [2].Sixty-three Egyptians were on board the Airbus A320, which crashed into shallow Persian Gulf waters Wednesday night after circling and trying to land in Bahrain [3].1, 1999, a plane carrying 217 mostly Egyptian passengers crashed into the Atlantic Ocean off Massachusetts 20% [1].CAIRO, Egypt The crash of a Gulf Air flight that killed 143 people in Bahrain is a disturbing deja vu for Egyptians: It is the second plane crash within a year to devastate this Arab country [2].Sixty-three Egyptians were on board the Airbus A320, which crashed into shallow Persian Gulf waters Wednesday night after circling and trying to land in Bahrain [3].31, 1999, a plane carrying 217 mostly Egyptian passengers crashed into the Atlantic Ocean off Massachusetts [16].In the hours just after the crash, relatives at the Cairo airport expressed anger and frustration at Gulf Air for the slow release of information [21].Gulf Air said it was sending a special plane to carry 134 relatives to Manama airport later Thursday [22]."All necessary measures have been taken to receive the families of the victims," Mohammed al-Sayed Abbas, the Egyptian ambassador to Bahrain, told Egyptian television 30% [1].CAIRO, Egypt The crash of a Gulf Air flight that killed 143 people in Bahrain is a disturbing deja vu for Egyptians: It is the second plane crash within a year to devastate this Arab 104 country [2].Sixty-three Egyptians were on board the Airbus A320, which crashed into shallow Persian Gulf waters Wednesday night after circling and trying to land in Bahrain [3].31, 1999, a plane carrying 217 mostly Egyptian passengers crashed into the Atlantic Ocean off Massachusetts [5].Walid Mourad, head of the Egyptian Pilots Association and a voice often heard in relation to the EgyptAir investigation, said Wednesday's crash is a tragedy for the Arab people as a whole [12].Hassan's uncle said he rushed to the Cairo airport after hearing a list of the passengers read on television [15].In the hours just after the crash, relatives at the Cairo airport expressed anger and frustration at Gulf Air for the slow release of information [21].Gulf Air said it was sending a special plane to carry 134 relatives to Manama airport later Thursday [22]."All necessary measures have been taken to receive the families of the victims," Mohammed al-Sayed Abbas, the Egyptian ambassador to Bahrain, told Egyptian television 40% [1].CAIRO, Egypt The crash of a Gulf Air flight that killed 143 people in Bahrain is a disturbing deja vu for Egyptians: It is the second plane crash within a year to devastate this Arab country [2].Sixty-three Egyptians were on board the Airbus A320, which crashed into shallow Persian Gulf waters Wednesday night after circling and trying to land in Bahrain [3].31, 1999, a plane carrying 217 mostly Egyptian passengers crashed into the Atlantic Ocean off Massachusetts [4].The cause has not been determined, providing no closure to the families, whose grief was reopened this month with the release of a factual report by the National Transportation Safety 105 Board [5].Walid Mourad, head of the Egyptian Pilots Association and a voice often heard in relation to the EgyptAir investigation, said Wednesday's crash is a tragedy for the Arab people as a whole [12].Hassan's uncle said he rushed to the Cairo airport after hearing a list of the passengers read on television [14].Hassan worked in a restaurant in Bahrain, his uncle said before disappearing into a room at the airport set aside for relatives desperate for news [15].In the hours just after the crash, relatives at the Cairo airport expressed anger and frustration at Gulf Air for the slow release of information [21].Gulf Air said it was sending a special plane to carry 134 relatives to Manama airport later Thursday [22]."All necessary measures have been taken to receive the families of the victims," Mohammed al-Sayed Abbas, the Egyptian ambassador to Bahrain, told Egyptian television [25].Egypt, which lacks the oil wealth of the Gulf and has an economy struggling to revive from decades of socialist stagnation, has a long tradition of sending workers to the Gulf to fill everything from skilled to menial jobs GISTSUMM VB1 PT 10% [1].CAIRO, Egypt The crash of a Gulf Air flight that killed 143 people in Bahrain is a disturbing deja vu for Egyptians: It is the second plane crash within a year to devastate this Arab country [2].Sixty-three Egyptians were on board the Airbus A320, which crashed into shallow Persian Gulf waters Wednesday night after circling and trying to land in Bahrain [25].Egypt, which lacks the oil wealth of the Gulf and has an economy struggling to revive from decades of socialist stagnation, has a long 106 tradition of sending workers to the Gulf to fill everything from skilled to menial jobs 20% [1].CAIRO, Egypt The crash of a Gulf Air flight that killed 143 people in Bahrain is a disturbing deja vu for Egyptians: It is the second plane crash within a year to devastate this Arab country [2].Sixty-three Egyptians were on board the Airbus A320, which crashed into shallow Persian Gulf waters Wednesday night after circling and trying to land in Bahrain [5].Walid Mourad, head of the Egyptian Pilots Association and a voice often heard in relation to the EgyptAir investigation, said Wednesday's crash is a tragedy for the Arab people as a whole [10].Many of the passengers on the Gulf Air flight were headed for jobs in Bahrain or elsewhere in the Gulf [15].In the hours just after the crash, relatives at the Cairo airport expressed anger and frustration at Gulf Air for the slow release of information [25].Egypt, which lacks the oil wealth of the Gulf and has an economy struggling to revive from decades of socialist stagnation, has a long tradition of sending workers to the Gulf to fill everything from skilled to menial jobs 30% [1].CAIRO, Egypt The crash of a Gulf Air flight that killed 143 people in Bahrain is a disturbing deja vu for Egyptians: It is the second plane crash within a year to devastate this Arab country [2].Sixty-three Egyptians were on board the Airbus A320, which crashed into shallow Persian Gulf waters Wednesday night after circling and trying to land in Bahrain [3].On Oct 31, 1999, a plane carrying 217 mostly Egyptian passengers crashed into the Atlantic Ocean off Massachusetts [5].Walid Mourad, head of the Egyptian Pilots Association and a voice often heard in relation 107 to the EgyptAir investigation, said Wednesday's crash is a tragedy for the Arab people as a whole [10].Many of the passengers on the Gulf Air flight were headed for jobs in Bahrain or elsewhere in the Gulf [15].In the hours just after the crash, relatives at the Cairo airport expressed anger and frustration at Gulf Air for the slow release of information [21].Gulf Air said it was sending a special plane to carry 134 relatives to Manama airport later Thursday [25].Egypt, which lacks the oil wealth of the Gulf and has an economy struggling to revive from decades of socialist stagnation, has a long tradition of sending workers to the Gulf to fill everything from skilled to menial jobs 40% [1].CAIRO, Egypt The crash of a Gulf Air flight that killed 143 people in Bahrain is a disturbing deja vu for Egyptians: It is the second plane crash within a year to devastate this Arab country [2].Sixty-three Egyptians were on board the Airbus A320, which crashed into shallow Persian Gulf waters Wednesday night after circling and trying to land in Bahrain [3].On Oct 31, 1999, a plane carrying 217 mostly Egyptian passengers crashed into the Atlantic Ocean off Massachusetts [5].Walid Mourad, head of the Egyptian Pilots Association and a voice often heard in relation to the EgyptAir investigation, said Wednesday's crash is a tragedy for the Arab people as a whole [10].Many of the passengers on the Gulf Air flight were headed for jobs in Bahrain or elsewhere in the Gulf [14].Hassan worked in a restaurant in Bahrain, his uncle said before disappearing into a room at the airport set aside for relatives desperate for news [15].In the hours just after the crash, relatives 108 at the Cairo airport expressed anger and frustration at Gulf Air for the slow release of information [21].Gulf Air said it was sending a special plane to carry 134 relatives to Manama airport later Thursday [22].Mohammed al-Sayed Abbas, the Egyptian ambassador to Bahrain, told Egyptian television [24].In Bahrain, relatives were beginning the wrenching process of identifying the victims from photographs taken after the bodies were retrieved from the Gulf [25].Egypt, which lacks the oil wealth of the Gulf and has an economy struggling to revive from decades of socialist stagnation, has a long tradition of sending workers to the Gulf to fill everything from skilled to menial jobs WEBSUMM VB1 PT 10% [10]: Many of the passengers on the Gulf Air flight were headed for jobs in Bahrain or elsewhere in the Gulf [15]: In the hours just after the crash, relatives at the Cairo airport expressed anger and frustration at Gulf Air for the slow release of information [21]: Gulf Air said it was sending a special plane to carry 134 relatives to Manama airport later Thursday 20% [1]: CAIRO, Egypt The crash of a Gulf Air flight that killed 143 people in Bahrain is a disturbing deja vu for Egyptians: It is the second plane crash within a year to devastate this Arab country [10]: Many of the passengers on the Gulf Air flight were headed for jobs in Bahrain or elsewhere in the Gulf [11]: Rida Hassan was one of those escaping Egypt's moribund economy for work in the oil-rich Gulf [15]: In the hours just after the crash, relatives at the Cairo airport expressed anger and frustration at Gulf Air for the slow release 109 of information [21]: Gulf Air said it was sending a special plane to carry 134 relatives to Manama airport later Thursday [24]: In Bahrain, relatives were beginning the wrenching process of identifying the victims from photographs taken after the bodies were retrieved from the Gulf 30% [1]: CAIRO, Egypt The crash of a Gulf Air flight that killed 143 people in Bahrain is a disturbing deja vu for Egyptians: It is the second plane crash within a year to devastate this Arab country [2]: Sixty-three Egyptians were on board the Airbus A320, which crashed into shallow Persian Gulf waters Wednesday night after circling and trying to land in Bahrain [10]: Many of the passengers on the Gulf Air flight were headed for jobs in Bahrain or elsewhere in the Gulf [11]: Rida Hassan was one of those escaping Egypt's moribund economy for work in the oil-rich Gulf [12]: Hassan's uncle said he rushed to the Cairo airport after hearing a list of the passengers read on television [15]: In the hours just after the crash, relatives at the Cairo airport expressed anger and frustration at Gulf Air for the slow release of information [21]: Gulf Air said it was sending a special plane to carry 134 relatives to Manama airport later Thursday [24]: In Bahrain, relatives were beginning the wrenching process of identifying the victims from photographs taken after the bodies were retrieved from the Gulf 40% [1]: CAIRO, Egypt The crash of a Gulf Air flight that killed 143 people in Bahrain is a disturbing deja vu for Egyptians: It is the second plane crash within a year to devastate this Arab country 110 [2]: Sixty-three Egyptians were on board the Airbus A320, which crashed into shallow Persian Gulf waters Wednesday night after circling and trying to land in Bahrain [10]: Many of the passengers on the Gulf Air flight were headed for jobs in Bahrain or elsewhere in the Gulf [11]: Rida Hassan was one of those escaping Egypt's moribund economy for work in the oil-rich Gulf [12]: Hassan's uncle said he rushed to the Cairo airport after hearing a list of the passengers read on television [14]: Hassan worked in a restaurant in Bahrain, his uncle said before disappearing into a room at the airport set aside for relatives desperate for news [15]: In the hours just after the crash, relatives at the Cairo airport expressed anger and frustration at Gulf Air for the slow release of information [21]: Gulf Air said it was sending a special plane to carry 134 relatives to Manama airport later Thursday [22]: "All necessary measures have been taken to receive the families of the victims," Mohammed al-Sayed Abbas, the Egyptian ambassador to Bahrain, told Egyptian television [24]: In Bahrain, relatives were beginning the wrenching process of identifying the victims from photographs taken after the bodies were retrieved from the Gulf [25]: Egypt, which lacks the oil wealth of the Gulf and has an economy struggling to revive from decades of socialist stagnation, has a long tradition of sending workers to the Gulf to fill everything from skilled to menial jobs 111 ... loại bàii toán văn hệ thống tóm tắt có sẵn Khái niệm tóm tắt văn Phân loại toán tóm tắt văn Các hệ thống có sẵn 1.1 KHÁI NIỆM TÓM TẮT VĂN BẢN Sự quan tâm đến tóm tắt văn xuất vào cuối thập niên... email thương mại vài dòng.Đó khả mà hệ thống Tóm tắt văn mang lại Vậy tóm tắt văn ? Tóm tắt văn kỹ thuật mà máy tính tự động tạo tóm tắt hay nhiều văn nói cách khác tóm tắt văn trình rút gọn... liệu nguồn để tạo tóm tắt theo văn xuôi 15 ƒ Tóm tắt tóm lược ( abstract-summary ) Một hệ thống tóm tắt trừu tượng tạo tóm tắt, trích rút tóm tắt Tức tóm tắt chứa phần văn (các từ câu ) tài liệu