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ahmedferradj · 2 years ago

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Data mining

1.What's Data mining ?

Datamining is the process of extracting and discovering patterns in large datasets involving methods at the intersection of machine learning, statistics and database systems. Datamining is interdisciplinary subfield of computer-science and statistics with overall goal of extracting information (with intelliegent methods) from a data set and transforming the information into a comprensible structure for further use. Data mining is the analysis step of The KDD process "Knowledge discovery in database".

2.What's KDD process ?

KDD process is known as "Knowledge Discovery in Database".It"s a multi-step process of finding knowledge from large data sets and emphasizes the high-level application of particular datamining methods.It's of interests to researchers in machine learning, pattern recognition, databases, ststistics, artificial intelligence, knowledge aquisition for experts systems and data-visualization. The picture below defines the different steps of KDD process and each of those steps have an input and output entity. The KDD process can't be executed without beginning on data.

3.What are the different steps of the KDD process ?

The overall process of finding and interpretting patterns from data involves the repeated application of the following steps mentioned in the graph above :

Selection : we create a target data set by seecting a part of the overall data set as a sample then focusing on a subset of variables on which discovery is to be performed. The result of these step is a subset of data considered as a sample.

Preprocessing : These step of the KDD process takes the target data set as an input then it applyes data cleaning by removing the noise from the input data set then restucturing the data set. The output of these operation is a preprocessed dataset that can be able to be transformed in the next step.

Data transformation : These step takes the preprocessed data as input and tres to find some useful features depending on the goal of the task and reducing dimension to execute an effective learining datamining.

Data mining : in this phase we will descide whether the goal of KDD process is classification, regression, clustering ...etc. Discover the patterns of interests.

Interpretation : Interpretating mined patterns and consolidating discovered knowledge.

4.What are data mining tasks ?

There are several steps that are defined in the sub-process of KDD especially in datamining steps. In Data mining, there are 02 types of data mining that are :

Predictive mining: predective data mining is the analysis done to predict a future event or other data or trends and to predict something will happen in the near future. Predective data mining offers a better future analysis and to make better decisions to add a value in predective analytics like for example predecting the future customer of a defined service, define the future price of oil and gaz in the world market, define the next ill of an international pandemic, define the future political conflict ... etc. There are 4 types of descriptive data mining tasks which are :

Classification analysis : It is used to retrieve critical and pertinent data and metadata. It categorizes information into various groups. Classification Analysis is best demonstrated by email providers. They use algorithms to determine whether or not a message is legitimate.

Regression Analysis : It tries to express the interdependence of variables. Forecasting and prediction are common applications.

Time Serious Analysis : It is a series of well-defined data points taken at regular intervals.

Prediction Analysis : It is related to time series, but the time isn’t restricted.

Descriptive mining : descriptive data mining is to describe data and make data more readable to human beings, it's used to extract information from previous events and data and to discovering an interesting patterns and association behind data. It's also used to exract correlations, relationships between features and finding new laws and regularities based on data. There are four different types of Descriptive Data Mining tasks. They are as follows :

Clustering analysis : It is the process of determining which data sets are similar to one another. For example, to increase conversion rates, clusters of customers with similar buying habits can be grouped together with similar products.

Summerazation analysis : It entails methods for obtaining a concise description of a dataset. For example, summarising a large number of items related to Christmas season sales provides a general description of the data, which can be extremely useful to sales and marketing managers.

Association rules analysis : This method aids in the discovery of interesting relationships between various variables in large databases. The retail industry is the best example. As the holiday season approaches, retail stores stock up on chocolates, with sales increasing before the holiday, which is accomplished through Data Mining.

Sequence discovery analysis : It's all about how to do something in a specefic order. For instance, a user may frequently purchase shaving gel before purchasing razor in a store.It all comes down to the order in which the user purchases the product, and the store owner can then arrange the items accordingly.

5.Links :

#ahmed #ferradj #artificial intelligence #software #web #data #mining

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nesiacha · 1 year ago

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Fernand and Helene Iveton a couple in the Algerian revolution the beginning of the End (part III)

In the previous post, we discovered the impact of Henri Maillot's death on Fernand Iveton. Together with a group including Félix Colozzi, Mohamed Hachelaf, Abdelkader and Jacqueline Guerroudj, Georges Accampora, and Mohamed Bennaceur, also known as Tewfik, Yahia Briki, they formed the Commando of Greater Algiers. They were supported by chemists like Daniel Timsit and Taleb Abderrahmane, a maquisard who came down from the maquis to assist the FLN in Algiers. Their operations included sabotaging wagons at the port and setting fire to international cork factories. One day, Fernand Iveton was assigned the mission to eliminate Gerard Etienne, a member of the colonialist organization Main Rouge, an ancestor of the notorious OAS. Fernand agreed, but the operation failed, and Mohamed Hachelaf took over the task.

To better understand the following events, it is important to contextualize Algiers in 1956. Executions of FLN militants by guillotine were in full swing, starting with the Algerian revolutionaries Ahmed Zabana and Abdelkader Ferradj, with many others following. These were mock trials under a military tribunal, where even the condemned were denied execution by firing squad—a practice viewed as an insult, which even the staunchly pro-colonial executioner of Algiers admitted should logically have been a firing squad given the military tribunal setting. However, many FLN militants, as well as innocent Algerians unrelated to the FLN, were executed by guillotine. This colonial "justice" was a farce, the extent of which would soon become apparent.

The bombing on Rue de Thèbes in August 1956 was a turning point. Two ORAF members, with police complicity, planted a bomb just before the Algerians' curfew to maximize casualties. The bomb exploded at 11:50 PM, killing over 80 people and seriously injuring 14. Many families in the Casbah were left homeless and without assistance. Everyone knew the culprits, but the incident was met with general indifference. Only a few lines were written about the tragedy, and the investigation falsely blamed Algerians for the attack. However, the act was claimed by a leaflet signed by the "Committee of Forty," which declared that for every European killed, a block of the Casbah would explode. Among the perpetrators was sub-prefect Achiary, known for his role in the May 8, 1945 massacre of Algerians.

The Algerians in Algiers were outraged and sought revenge. The FLN calmed them, promising similar retaliatory actions. This latest attack on Algerian civilians erased the last scruples most Algerian nationalists had about bombing locations frequented by European civilians. Violence escalated to a new level, with the FLN planting multiple bombs, including in cafes. This marked the beginning of what is known as the Battle of Algiers, although some historians like Gilbert Meynier prefer the term "Repression of Algiers" for this episode. The explanations for this part of history are vast and would require multiple posts.

Most PCA members integrated into the FLN disagreed with this approach. They supported targeting ultra-colonialists who already killed and generals involved in crimes but opposed killing innocent European civilians. Fernand Iveton naturally shared this view. He confided this in his wife Hélène, without giving her operation details for her safety and that of the network. He condemned the indiscriminate violence against European civilians, including children,impoverished civils , and believed it would lead to a dead end.

Nevertheless, Fernand was committed to the revolution. He decided to sabotage the gas plant where he worked using a bomb, ensuring no one would be injured. Taleb Abderrahmane made two bombs, Jacqueline Guerroudj transported them, and gave one to Fernand, who set it to go off late in the evening to avoid casualties. After this action, he planned to join the maquis ( The rule of the FLN was that to become a maquisard, one had to be wanted). However, the plant foreman, Oriol, suspicious of Fernand due to his CGT delegate activities, saw him enter a room with a beach bag and leave empty-handed. He alerted the police, who found the bomb. Fernand was arrested, marking the beginning of a nightmare for him and his loved ones.

Fernand was insulted by the police. Paul Teitgen, secretary-general of the Algiers prefecture, had forbidden the use of torture on Fernand Iveton, but his orders were ignored. A police commissioner assured his officers they would be covered for whatever they did. Fernand was brutally tortured, both physically and psychologically. He held on for his wife, Henri, his comrades, and others, needing to last at least 24 (or 48) hours to protect the network and evacuate everyone he knew. He was also threatened with harm to his wife.

The police demanded the location of the second bomb and his accomplices. When Fernand felt he might break, he cleverly claimed a blonde woman had given him the bombs (Jacqueline Guerroudj was brunette), misleading the police into suspecting Raymonde Peschard, a well-known PCA militant. They mistakenly believed she was behind the Milk Bar bombing (actually carried out by Zohra Drif). Raymonde Peschard, whose alias was Taous, evaded arrest and joined the ALN before being killed by the French army in the maquis on November 26, 1957.

When Fernand felt he could no longer hold out, he named Félix Colozzi and Mohamed Hachelaf, believing they had escaped. Mohamed Hachelaf's wife was arrested, but Félix Colozzi was not evacuated in time due to suspicious movements near his home. Both Fernand and Félix were tortured horribly. Helene, following Fernand's instructions, destroyed his hidden papers when the police arrived at their home. She delayed them by pretending to sleep and arguing through the window, buying time.I think her experience of hiding resistance fighters during the occupation of France by Nazi Germany must have helped her to deal with these situation . Ultimately, she let them in after ensuring any evidence was destroyed. The police arrested her as well.

Helene faced police attempts to turn her against Fernand. They falsely claimed he was unfaithful, but she retorted that it was fashionable to be cheated on and the police commissioner’s wife was probably cheating on him too. When asked about her knowledge of her husband's militancy, she lied, claiming ignorance and stating her love for him. The commissioner grew angry, but Helene remained calm. She was put in a cell next to prostitutes who cheered her defiance against a policeman insulting her husband. She earned the nickname "the tigress."

Fernand, meanwhile, was taunted by soldiers who showed him newspapers branding him a bloodthirsty criminal. Fernand mislead the police about an FLN hideout, manage to escape but was recaptured and beaten again.

The police released Hélène. She made sure not to acknowledge the police officers and took a taxi. The driver, named Farouk, noticed that she was sad. She confided in him, explaining that she could not bear the thought of her husband being tortured. This likely brought back painful memories of her uncle being tortured and killed by a Nazi officer during World War II in Poland, as mentioned in the first part. When Farouk learned that she was Fernand Iveton's wife, he was completely surprised. While Iveton was seen as a brigand and a traitor by the colonial authorities, he was becoming a hero to the Algerian population. When Hélène tried to pay for the taxi, the driver refused, saying that the wives of fighters do not pay.

The French authorities, including Robert Lacoste, celebrated thos. Soustelle falsely claimed Fernand wanted to blow up the entire city. Lacoste demanded Fernand's execution, a move meant to discredit the Algerian movement and paint it as communist-led to reduce American support.

It is important to understand that during the UN meetings, France was frequently called out for its conduct in Algeria and faced increasing international criticism from many countries such as Tunisia, Egypt, and others. The USSR remained neutral on this issue until it aligned with Nasser, but the FLN was able to count on significant diplomatic support from China as well as from the United States. In New York, M’Hamed Yazid and Hocine Ait Ahmed, later replaced by Abdelkader Chanderli, maintained contacts through the UN with the Americans.

An anecdote: in 1957, Senator Kennedy, although he was speaking in a personal capacity and not on behalf of the American government, stated that it was necessary to "accelerate the movement towards independence in Algerian policy." But now, an communist named Fernand Iveton was caught in the act of sabotage in the name of Algeria’s independence. This was an opportunity to try to discredit the Algerian movement and suggest that this revolution was primarily the work of communists, perhaps even under Moscow's influence, and that consequently, the Americans should stop supporting them. This was a desperate and foolish strategy by the French government, but Iveton paid the high price fot these. French newspapers like Le Monde gleefully branded him a brigand. Not to mention the colonial newspapers.

The French Communist Party abandoned him. Helene sought Gaston Amblard’s help, but the PCF forbade it, calling Fernand’s actions a "provocation" ( words of Leon Feix). The lawyer Gisèle Halimi explained in her book Le lait de l'oranger that she was outraged and ready to defend him, and she sent him a note. He sincerely thanked her but said that as a communist, he could only accept help from a communist lawyer. . Ultimately, Albert Smajda, a third-year communist trainee lawyer, defended Fernand, assisted by Charles Lainné of Secours Catholique a very good lawyer who defend the equality between algerians and Pieds Noirs . Both knew Fernand should not be executed in theory, but the charged atmosphere made anything possible. Fernand fought for clemency, refusing to be demoralized and the two braves and engaged lawyers will fight for save Fernand Iveton life.

Helene prepared clean clothes for Fernand for his trial, insisting they be delivered in person. Initially refused, the prison director, moved by her determination, assured that Fernand would receive them. On her way out, she noticed a policeman following her and told him to get out. Fernand and Helene, committed to each other and their cause, prepared for a new battle for save his life.

#algeria #revolution #algerian revolution #USA #france

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