diff --git a/YACOSCore/ejbModule/org/yacos/core/article/Article.java b/YACOSCore/ejbModule/org/yacos/core/article/Article.java
new file mode 100644
index 0000000..40152f0
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/article/Article.java
@@ -0,0 +1,241 @@
+package org.yacos.core.article;
+
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Collection;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.JoinTable;
+import javax.persistence.ManyToMany;
+import javax.persistence.ManyToOne;
+import javax.persistence.OneToMany;
+
+import org.yacos.core.conferences.Conference;
+import org.yacos.core.users.User;
+
+@Entity
+public class Article implements Serializable {
+
+	/**
+	 * 
+	 */
+	private static final long serialVersionUID = 1L;
+
+	@Id
+	@GeneratedValue(strategy=GenerationType.AUTO)
+	private int id;
+	private String title;
+	private String topic;
+	private String URL_article;
+	private String mainAuthor;
+	private ArrayList<String> secondaryAuthors;
+	
+	/**
+	 * The conference this article has been submitted for
+	 */
+	@ManyToOne(targetEntity=Conference.class)
+	@JoinColumn(name="conference_id",nullable=false)
+	private Conference conference;
+	
+	/**
+	 * The referees reviewing this article
+	 */
+	@ManyToMany(targetEntity=User.class)
+	@JoinTable(
+		name="articles_referees_map",
+		joinColumns=@JoinColumn(name="user_id"),
+		inverseJoinColumns=@JoinColumn(name="article_id")
+	)
+	private Collection<User> referees;
+	
+	/**
+	 * The PC Members responsible for this article evaluation
+	 */
+	@ManyToMany(targetEntity=User.class)
+	@JoinTable(
+		name="articles_pcmembers_map",
+		joinColumns=@JoinColumn(name="user_id"),
+		inverseJoinColumns=@JoinColumn(name="article_id")
+	)
+	private Collection<User> pcMembers;
+	
+	@OneToMany(targetEntity=Preference.class,mappedBy="article")
+	private Collection<Preference> preferences;
+	
+	private int state;
+
+	public enum state {
+		SUMMARY, FINAL
+	};
+
+	public Article() {
+		secondaryAuthors = new ArrayList<String>();
+	}
+
+	public Article(int reference, String title, String topic,
+			String url_article, String mainAuthor,
+			ArrayList<String> secondaryAuthor, int state) {
+		this.id = reference;
+		this.title = title;
+		this.topic = topic;
+		this.URL_article = url_article;
+		this.mainAuthor = mainAuthor;
+		this.secondaryAuthors = secondaryAuthor;
+		this.state = state;
+		secondaryAuthors = new ArrayList<String>();
+		referees = new ArrayList<User>();
+		pcMembers = new ArrayList<User>();
+	}
+
+	@Id
+	@GeneratedValue(strategy=GenerationType.AUTO)
+	public int getId() {
+		return id;
+	}
+
+	public void setId(int id) {
+		this.id = id;
+	}
+
+	public String getTitle() {
+		return title;
+	}
+
+	public void setTitle(String title) {
+		this.title = title;
+	}
+
+	public String getTopic() {
+		return topic;
+	}
+
+	public void setTopic(String topic) {
+		this.topic = topic;
+	}
+
+	public String getURL_article() {
+		return URL_article;
+	}
+
+	public void setURL_article(String url_article) {
+		URL_article = url_article;
+	}
+
+	public String getMainAuthor() {
+		return mainAuthor;
+	}
+
+	public void setMainAuthor(String mainAuthor) {
+		this.mainAuthor = mainAuthor;
+	}
+
+	public ArrayList<String> getSecondaryAuthors() {
+		return secondaryAuthors;
+	}
+
+	public void setSecondaryAuthors(ArrayList<String> secondaryAuthors) {
+		this.secondaryAuthors = secondaryAuthors;
+	}
+
+	public int getState() {
+		return state;
+	}
+
+	public void setState(int state) {
+		this.state = state;
+	}
+	
+	@ManyToMany(targetEntity=User.class)
+	@JoinTable(
+		name="articles_referees_map",
+		joinColumns=@JoinColumn(name="user_id"),
+		inverseJoinColumns=@JoinColumn(name="article_id")
+	)
+	public Collection<User> getReferees(){
+		return referees;
+	}
+	
+	/**
+	 * @param referees the referees to set
+	 */
+	@ManyToMany(targetEntity=User.class)
+	@JoinTable(
+		name="articles_referees_map",
+		joinColumns=@JoinColumn(name="user_id"),
+		inverseJoinColumns=@JoinColumn(name="article_id")
+	)
+	public void setReferees(Collection<User> referees) {
+		this.referees = referees;
+	}
+
+	@ManyToMany(targetEntity=User.class)
+	@JoinTable(
+		name="articles_pcmembers_map",
+		joinColumns=@JoinColumn(name="user_id"),
+		inverseJoinColumns=@JoinColumn(name="article_id")
+	)
+	public Collection<User> getPCMembers(){
+		return pcMembers;
+	}
+	@ManyToMany(targetEntity=User.class)
+	@JoinTable(
+		name="articles_pcmembers_map",
+		joinColumns=@JoinColumn(name="user_id"),
+		inverseJoinColumns=@JoinColumn(name="article_id")
+	)
+	public void setPCMembers(Collection<User> pcMembers){
+		this.pcMembers = pcMembers;
+	}
+	
+	public void assignToPCMember(User pcMember){
+		// TODO : Checking if the User is a pcMember for this conference (not implemented yet)
+		//if(pcMember.hasRoleForConference(RoleType.PCmember, this.conference)){
+			if(! pcMembers.contains(pcMember)){
+				pcMembers.add(pcMember);
+			} else {
+				//throw new DuplicateAssignationException();
+			}
+		//}
+	}
+
+	public void delegateTo(User referee, User pcMember) {
+		if(pcMembers.contains(pcMember)){
+			if(! referees.contains(referee)){
+				referees.add(referee);
+			}
+		}
+	}
+	
+	@ManyToOne(targetEntity=Conference.class)
+	public Conference getConference(){
+		return conference;
+	}
+	
+	@ManyToOne(targetEntity=Conference.class)
+	public void setConference(Conference conference){
+		this.conference = conference;
+	}
+	
+	/**
+	 * @return the preferences
+	 */
+	@OneToMany(targetEntity=Preference.class,mappedBy="article")
+	public Collection<Preference> getPreferences() {
+		return preferences;
+	}
+
+	/**
+	 * @param preferences the preferences to set
+	 */
+	@OneToMany(targetEntity=Preference.class,mappedBy="article")
+	public void setPreferences(Collection<Preference> preferences) {
+		this.preferences = preferences;
+	}
+
+	public boolean hasMember(){
+		return false;
+	}
+}
diff --git a/YACOSCore/ejbModule/org/yacos/core/article/ArticleManagerBean.java b/YACOSCore/ejbModule/org/yacos/core/article/ArticleManagerBean.java
new file mode 100644
index 0000000..292e22d
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/article/ArticleManagerBean.java
@@ -0,0 +1,103 @@
+package org.yacos.core.article;
+
+import java.io.Serializable;
+import java.util.List;
+
+import javax.ejb.Stateless;
+import javax.persistence.EntityManager;
+import javax.persistence.NoResultException;
+import javax.persistence.PersistenceContext;
+import javax.persistence.Query;
+
+import org.yacos.core.users.User;
+
+@Stateless
+public class ArticleManagerBean implements IArticleManager, Serializable {
+
+	/**
+	 * 
+	 */
+	private static final long serialVersionUID = 1L;
+
+	@PersistenceContext
+	EntityManager em;
+
+	public ArticleManagerBean() {
+		
+	}
+
+	public void addArticle(Article a) {
+		em.persist(a);
+	}
+
+	@SuppressWarnings("unchecked")
+	public List<Article> getArticles() {
+		return em.createQuery("from Article a ORDER BY a.title").getResultList();
+	}
+
+	public void updateArticle(Integer id, Article newArticle) {
+		removeArticle(getArticle(id));
+		newArticle.setId(id);
+		addArticle(newArticle);
+		em.flush();
+	}
+
+	public void removeArticle(Article a) {
+		em.remove(a);
+		em.flush();
+	}
+
+	public Article getArticle(Integer id) {
+		return em.find(Article.class, id);
+	}
+	
+	public void assignArticleToPCMember(Article article,User pcMember){
+		article.assignToPCMember(pcMember);
+		em.flush();
+	}
+
+	public List<User> getArticlePCMembers(Article article) {
+		return (List<User>) article.getPCMembers();
+	}
+	
+	public void delegateArticleToReferee(Article article, User referee, User pcMember){
+		article.delegateTo(referee,pcMember);
+	}
+
+	public List<User> getArticleReferees(Article article) {
+		return (List<User>) article.getReferees();
+	}
+
+	public Preference getArticlePreferenceForUser(Article article,
+			String pcMemberLogin) {
+		Query query = em.createQuery("SELECT p FROM Preference p WHERE p.article.id = :articleid AND p.pcMember.id = :pcmemberlogin");
+		query.setParameter("articleid",article.getId());
+		query.setParameter("pcmemberlogin", pcMemberLogin);
+		try {
+			return (Preference) query.getSingleResult();
+		} catch (NoResultException e) {
+			return null;
+		}
+	}
+
+	public void setArticlePreferences(Article article,
+			List<Preference> preferences) {
+		article.setPreferences(preferences);
+	}
+
+	public void addArticlePreference(Preference preference) {
+		if(! em.contains(preference)){
+			em.persist(preference);
+		}
+	}
+
+	public void addArticlePreference(Integer article_id, String userLogin, String preferenceValue) {
+		Preference preference = new Preference();
+		Article article = getArticle(article_id);
+		preference.setArticle(article);
+		User pcMember = em.find(User.class, userLogin);
+		preference.setPcMember(pcMember);
+		preference.setPreference(preferenceValue);
+		em.persist(preference);
+	}
+}
diff --git a/YACOSCore/ejbModule/org/yacos/core/article/Delegation.java b/YACOSCore/ejbModule/org/yacos/core/article/Delegation.java
new file mode 100644
index 0000000..42584b6
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/article/Delegation.java
@@ -0,0 +1,105 @@
+/**
+ * 
+ */
+package org.yacos.core.article;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.ManyToOne;
+import org.yacos.core.users.User;
+
+/**
+ * @author christiancorsano
+ *
+ */
+@Entity
+public class Delegation {
+	/**
+	 * Id mandatory in every entity.
+	 */
+	@Id
+	@GeneratedValue(strategy=GenerationType.AUTO)
+	private Integer id;
+	@ManyToOne(targetEntity=Article.class)
+	@JoinColumn(name="article_id")
+	private Article article;
+	@ManyToOne(targetEntity=User.class)
+	@JoinColumn(name="pcmember_id")
+	private User pcMember;
+	@ManyToOne(targetEntity=User.class)
+	@JoinColumn(name="referee_id")
+	private User referee;
+	
+	/**
+	 * @return the id
+	 */
+	public Integer getId() {
+		return id;
+	}
+	/**
+	 * @param id the id to set
+	 */
+	public void setId(Integer id) {
+		this.id = id;
+	}
+	
+	/**
+	 * Article being evaluated through this delegation
+	 * @return the article
+	 */
+	@ManyToOne(targetEntity=Article.class)
+	@JoinColumn(name="article_id")
+	public Article getArticle() {
+		return article;
+	}
+	/**
+	 * Define the article evaluated through this delegation
+	 * @param article the article to set
+	 */
+	@ManyToOne(targetEntity=Article.class)
+	@JoinColumn(name="article_id")
+	public void setArticle(Article article) {
+		this.article = article;
+	}
+	/**
+	 * PCMember that delegated the article to a referee
+	 * @return the pcMember
+	 */
+	@ManyToOne(targetEntity=User.class)
+	@JoinColumn(name="pcmember_id")
+	public User getPcMember() {
+		return pcMember;
+	}
+	/**
+	 * Set PCMember that delegated the article to a referee
+	 * @param pcMember the pcMember to set
+	 */
+	@ManyToOne(targetEntity=User.class)
+	@JoinColumn(name="pcmember_id")
+	public void setPcMember(User pcMember) {
+		this.pcMember = pcMember;
+	}
+	/**
+	 * Get the referee that will evaluate this article
+	 * @return the referee
+	 */
+	@ManyToOne(targetEntity=User.class)
+	@JoinColumn(name="referee_id")
+	public User getReferee() {
+		return referee;
+	}
+	/**
+	 * Get 
+	 * @param referee the referee to set
+	 */
+	@ManyToOne(targetEntity=User.class)
+	@JoinColumn(name="referee_id")
+	public void setReferee(User referee) {
+		this.referee = referee;
+	}
+	
+	
+}
diff --git a/YACOSCore/ejbModule/org/yacos/core/article/IArticleManager.java b/YACOSCore/ejbModule/org/yacos/core/article/IArticleManager.java
new file mode 100644
index 0000000..bdc76c5
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/article/IArticleManager.java
@@ -0,0 +1,20 @@
+package org.yacos.core.article;
+
+import java.util.List;
+import javax.ejb.Remote;
+
+@Remote
+public interface IArticleManager {
+	public Article getArticle(Integer id);
+	public void addArticle(Article a);
+	public void removeArticle(Article a);
+	public void updateArticle(Integer id, Article newArticle);
+	
+	public List<?> getArticlePCMembers(Article article);
+	public List<?> getArticleReferees(Article article);
+	public Preference getArticlePreferenceForUser(Article article, String pcMemberLogin);
+	public void setArticlePreferences(Article article, List<Preference> preferences);
+	public void addArticlePreference(Integer article_id, String userLogin, String preferenceValue);
+	
+	public List<Article> getArticles();
+}
diff --git a/YACOSCore/ejbModule/org/yacos/core/article/Preference.java b/YACOSCore/ejbModule/org/yacos/core/article/Preference.java
new file mode 100644
index 0000000..10d206e
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/article/Preference.java
@@ -0,0 +1,98 @@
+/**
+ * 
+ */
+package org.yacos.core.article;
+
+import java.io.Serializable;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.ManyToOne;
+
+import org.yacos.core.users.User;
+
+/**
+ * @author christiancorsano
+ *
+ */
+@Entity
+public class Preference implements Serializable {
+	/**
+	 * 
+	 */
+	private static final long serialVersionUID = 1L;
+	/**
+	 * Id mandatory in every entity.
+	 */
+	@Id
+	@GeneratedValue(strategy=GenerationType.AUTO)
+	private Integer id;
+	@ManyToOne(targetEntity=User.class)
+	@JoinColumn(name="pcmember_id",nullable=false)
+	private User pcMember;
+	@ManyToOne(targetEntity=Article.class)
+	@JoinColumn(name="article_id",nullable=false)
+	private Article article;
+	
+	
+	private String preference;
+
+	/**
+	 * @return the id
+	 */
+	@Id
+	@GeneratedValue(strategy=GenerationType.AUTO)
+	public Integer getId() {
+		return id;
+	}
+	/**
+	 * @param id the id to set
+	 */
+	@Id
+	@GeneratedValue(strategy=GenerationType.AUTO)
+	public void setId(Integer id) {
+		this.id = id;
+	}
+	
+	/**
+	 * @return the pcMember
+	 */
+	@ManyToOne(targetEntity=User.class)
+	@JoinColumn(name="pcmember_id",nullable=false)
+	public User getPcMember() {
+		return pcMember;
+	}
+	/**
+	 * @param pcMember the pcMember to set
+	 */
+	@ManyToOne(targetEntity=User.class)
+	@JoinColumn(name="pcmember_id",nullable=false)
+	public void setPcMember(User pcMember) {
+		this.pcMember = pcMember;
+	}
+	/**
+	 * @return the article
+	 */
+	@ManyToOne(targetEntity=Article.class)
+	@JoinColumn(name="article_id",nullable=false)
+	public Article getArticle() {
+		return article;
+	}
+	/**
+	 * @param article the article to set
+	 */
+	@ManyToOne(targetEntity=Article.class)
+	@JoinColumn(name="article_id",nullable=false)
+	public void setArticle(Article article) {
+		this.article = article;
+	}
+	public String getPreference() {
+		return preference;
+	}
+	public void setPreference(String preference) {
+		this.preference = preference;
+	}
+}
diff --git a/YACOSCore/ejbModule/org/yacos/core/conferences/Conference.java b/YACOSCore/ejbModule/org/yacos/core/conferences/Conference.java
new file mode 100644
index 0000000..9aa3402
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/conferences/Conference.java
@@ -0,0 +1,156 @@
+package org.yacos.core.conferences;
+
+import java.io.Serializable;
+import java.util.Collection;
+import java.util.Date;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.OneToMany;
+import javax.persistence.OneToOne;
+import javax.persistence.Temporal;
+import javax.persistence.TemporalType;
+
+import org.yacos.core.article.Article;
+import org.yacos.core.users.User;
+
+@Entity
+public class Conference implements Serializable{
+	@Id
+	@GeneratedValue(strategy=GenerationType.AUTO)
+	private Integer id;
+	private String titre;
+	private String description;
+	private String otherInformations;
+	@Temporal(TemporalType.DATE)
+	private Date dateAbstract;
+	@Temporal(TemporalType.DATE)
+	private Date dateArticle;
+	@Temporal(TemporalType.DATE)
+	private Date dateEvaluation;
+	@Temporal(TemporalType.DATE)
+	private Date dateStart;
+	@Temporal(TemporalType.DATE)
+	private Date dateEnd;
+	
+	/*@OneToOne(targetEntity=User.class,optional=true)
+	@JoinColumn(name="chairman_id",nullable=true)
+	private User chairman;
+	*/
+	@OneToMany(targetEntity=Article.class,mappedBy="conference")
+	private Collection<Article> articles;
+
+	/**
+	 * @return the chairman
+	 */
+	/*@OneToOne(targetEntity=User.class,optional=true)
+	@JoinColumn(name="chairman_id",nullable=true)
+	public User getChairman() {
+		return chairman;
+	}
+*/
+	/**
+	 * @param chairman the chairman to set
+	 */
+	/*
+	@OneToOne(targetEntity=User.class,optional=true)
+	@JoinColumn(name="chairman_id",nullable=true)
+	public void setChairman(User chairman) {
+		this.chairman = chairman;
+	}
+	*/
+	@Temporal(TemporalType.DATE)
+    public Date getDataAbstract() {
+		return dateAbstract;
+	}
+
+	@Temporal(TemporalType.DATE)
+	public void setDataAbstract(Date dataAbstract) {
+		this.dateAbstract = dataAbstract;
+	}
+	@Temporal(TemporalType.DATE)
+	public Date getDateArticle() {
+		return dateArticle;
+	}
+	@Temporal(TemporalType.DATE)
+	public void setDateArticle(Date dateArticle) {
+		this.dateArticle = dateArticle;
+	}
+	@Temporal(TemporalType.DATE)
+	public Date getDateEnd() {
+		return dateEnd;
+	}
+	@Temporal(TemporalType.DATE)
+	public void setDateEnd(Date dateEnd) {
+		this.dateEnd = dateEnd;
+	}
+	@Temporal(TemporalType.DATE)
+	public Date getDateEvaluation() {
+		return dateEvaluation;
+	}
+	@Temporal(TemporalType.DATE)
+	public void setDateEvaluation(Date dateEvaluation) {
+		this.dateEvaluation = dateEvaluation;
+	}
+	@Temporal(TemporalType.DATE)
+	public Date getDateStart() {
+		return dateStart;
+	}
+	@Temporal(TemporalType.DATE)
+	public void setDateStart(Date dateStart) {
+		this.dateStart = dateStart;
+	}
+	public String getDescription() {
+		return description;
+	}
+	public void setDescription(String descirption) {
+		this.description = descirption;
+	}
+	public String getOtherInformations() {
+		return otherInformations;
+	}
+	public void setOtherInformations(String otherInformations) {
+		this.otherInformations = otherInformations;
+	}
+	public String getTitre() {
+		return titre;
+	}
+	public void setTitre(String titre) {
+		this.titre = titre;
+	}
+	public Integer getId() {
+		return id;
+	}
+	public void setId(Integer id) {
+		this.id = id;
+	}
+	
+	public Conference() {
+	}
+	
+	public Conference(String titre, String descirption, String infoComplementray, Date dataAbstract, Date dateArticle, Date dateEvaluation, Date dateStart, Date dateEnd) {
+		super();
+		this.id = id;
+		this.titre = titre;
+		this.description = descirption;
+		this.otherInformations = infoComplementray;
+		this.dateAbstract = dataAbstract;
+		this.dateArticle = dateArticle;
+		this.dateEvaluation = dateEvaluation;
+		this.dateStart = dateStart;
+		this.dateEnd = dateEnd;
+	}
+
+	@OneToMany(targetEntity=Article.class,mappedBy="articles")
+	public void setArticles(Collection<Article> articles) {
+		this.articles = articles;
+	}
+	
+	@OneToMany(targetEntity=Article.class,mappedBy="articles")
+	public Collection<Article> getArticles() {
+		return articles;
+	}
+}
diff --git a/YACOSCore/ejbModule/org/yacos/core/conferences/ConferenceManagerBean.java b/YACOSCore/ejbModule/org/yacos/core/conferences/ConferenceManagerBean.java
new file mode 100644
index 0000000..96722f8
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/conferences/ConferenceManagerBean.java
@@ -0,0 +1,42 @@
+package org.yacos.core.conferences;
+
+import javax.ejb.Stateless;
+import java.util.ArrayList;
+import java.util.List;
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import org.yacos.core.article.Article;
+
+@Stateless
+public class ConferenceManagerBean implements IConferenceManager {
+	@PersistenceContext
+    EntityManager em;
+
+	public void addConference(Conference conf) {
+		em.persist(conf);
+	}
+
+	@SuppressWarnings("unchecked")
+	public List<Conference> getConferences() {
+		 return em.createQuery("from Conference conf ORDER BY conf.id").getResultList();
+	}
+
+	public Conference getConference(Integer id) {
+		 return em.find(Conference.class, id);
+	}
+
+	public void remove(Integer id) {
+		Conference conf=this.getConference(id);
+	    em.remove(conf);
+	}
+
+	public void update(Conference newC, Integer id) { 
+		this.remove(id);
+		this.addConference(newC);
+	}
+
+	public List<Article> getArticles(Integer conference_id) {
+		return new ArrayList<Article>(getConference(conference_id).getArticles());
+	}
+
+}
diff --git a/YACOSCore/ejbModule/org/yacos/core/conferences/IConferenceManager.java b/YACOSCore/ejbModule/org/yacos/core/conferences/IConferenceManager.java
new file mode 100644
index 0000000..b19f875
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/conferences/IConferenceManager.java
@@ -0,0 +1,16 @@
+package org.yacos.core.conferences;
+
+import java.util.List;
+import javax.ejb.Remote;
+
+import org.yacos.core.article.Article;
+
+@Remote
+public interface IConferenceManager {
+    public void addConference(Conference conf);
+	public Conference getConference(Integer id);
+	public List<Conference> getConferences();
+	public void remove(Integer id);
+	public void update(Conference newC,Integer id);
+	public List<Article> getArticles(Integer id);
+}
diff --git a/YACOSCore/ejbModule/org/yacos/core/evaluation/Criterion.java b/YACOSCore/ejbModule/org/yacos/core/evaluation/Criterion.java
new file mode 100644
index 0000000..bf467c1
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/evaluation/Criterion.java
@@ -0,0 +1,105 @@
+/**
+ * 
+ */
+package org.yacos.core.evaluation;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.ManyToOne;
+
+import org.yacos.core.conferences.Conference;
+
+/**
+ * @author christiancorsano
+ *
+ */
+@Entity
+public class Criterion {
+	@Id
+	@GeneratedValue(strategy=GenerationType.AUTO)
+	private Integer id;
+	private String name;
+	private Integer min_rating;
+	private Integer max_rating;
+	
+	@ManyToOne(targetEntity=Conference.class)
+	@JoinColumn(name="conference_id",nullable=false)
+	private Conference conference;
+	
+	@ManyToOne(targetEntity=Conference.class)
+	@JoinColumn(name="conference_id",nullable=false)
+	public Conference getConference(){
+		return conference;
+	}
+	
+	/**
+	 * @param conference the conference to set
+	 */
+	@ManyToOne(targetEntity=Conference.class)
+	@JoinColumn(name="conference_id",nullable=false)
+	public void setConference(Conference conference) {
+		this.conference = conference;
+	}
+
+	/**
+	 * @return the id
+	 */
+	public Integer getId() {
+		return id;
+	}
+
+	/**
+	 * @param id the id to set
+	 */
+	public void setId(Integer id) {
+		this.id = id;
+	}
+
+
+
+	/**
+	 * @return the name of this criterion
+	 */
+	public String getName() {
+		return name;
+	}
+
+	/**
+	 * @param name the name of this criterion
+	 */
+	public void setName(String name) {
+		this.name = name;
+	}
+
+	/**
+	 * @return the minimum value for this criterion
+	 */
+	public Integer getMin() {
+		return min_rating;
+	}
+
+	/**
+	 * @param min the minimum value for this criterion
+	 */
+	public void setMin(Integer min) {
+		this.min_rating = min;
+	}
+
+	/**
+	 * @return the maximum value for this criterion
+	 */
+	public Integer getMax() {
+		return max_rating;
+	}
+
+	/**
+	 * @param max the maximum value for this criterion
+	 */
+	public void setMax(Integer max) {
+		this.max_rating = max;
+	}
+	
+}
diff --git a/YACOSCore/ejbModule/org/yacos/core/evaluation/EvaluationManager.java b/YACOSCore/ejbModule/org/yacos/core/evaluation/EvaluationManager.java
new file mode 100644
index 0000000..b10f5d8
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/evaluation/EvaluationManager.java
@@ -0,0 +1,28 @@
+/**
+ * 
+ */
+package org.yacos.core.evaluation;
+
+import java.util.List;
+import javax.ejb.Stateless;
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.persistence.Query;
+
+import org.yacos.core.article.Article;
+
+/**
+ * @author christiancorsano
+ *
+ */
+@Stateless
+public class EvaluationManager implements IEvaluationManager {
+	@PersistenceContext
+	EntityManager em;
+	
+	@SuppressWarnings("unchecked")
+	public List<Report> getReportsForArticle(Article article) {
+		Query q = em.createNativeQuery("from Report where article_id="+article.getId(), Report.class);
+		return q.getResultList();
+	}
+}
diff --git a/YACOSCore/ejbModule/org/yacos/core/evaluation/IEvaluationManager.java b/YACOSCore/ejbModule/org/yacos/core/evaluation/IEvaluationManager.java
new file mode 100644
index 0000000..0292ef8
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/evaluation/IEvaluationManager.java
@@ -0,0 +1,19 @@
+/**
+ * 
+ */
+package org.yacos.core.evaluation;
+
+import java.util.List;
+
+import javax.ejb.Remote;
+
+import org.yacos.core.article.Article;
+
+/**
+ * @author christiancorsano
+ *
+ */
+@Remote
+public interface IEvaluationManager {
+	public List<Report> getReportsForArticle(Article article);
+}
diff --git a/YACOSCore/ejbModule/org/yacos/core/evaluation/Rating.java b/YACOSCore/ejbModule/org/yacos/core/evaluation/Rating.java
new file mode 100644
index 0000000..03bb741
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/evaluation/Rating.java
@@ -0,0 +1,90 @@
+/**
+ * 
+ */
+package org.yacos.core.evaluation;
+
+import javax.persistence.Entity;
+import javax.persistence.FetchType;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.ManyToOne;
+
+/**
+ * @author christiancorsano
+ *
+ */
+@Entity
+public class Rating {
+	@Id
+	@GeneratedValue(strategy=GenerationType.AUTO)
+	private Integer id;
+	private Integer value;
+	@ManyToOne(targetEntity=Criterion.class,fetch=FetchType.EAGER)
+	@JoinColumn(name="criterion_id",nullable=false)
+	private Criterion criterion;
+	@ManyToOne(targetEntity=Report.class)
+	@JoinColumn(name="report_id",nullable=false)
+	private Report report;
+	/**
+	 * @return the id
+	 */
+	@Id
+	public Integer getId() {
+		return id;
+	}
+	/**
+	 * @param id the id to set
+	 */
+	@Id
+	public void setId(Integer id) {
+		this.id = id;
+	}
+	/**
+	 * @return the value
+	 */
+	public Integer getValue() {
+		return value;
+	}
+	/**
+	 * @param value the value to set
+	 */
+	public void setValue(Integer value) {
+		this.value = value;
+	}
+	/**
+	 * @return the criterion
+	 */
+	@ManyToOne(targetEntity=Criterion.class)
+	@JoinColumn(name="criterion_id",nullable=false)
+	public Criterion getCriterion() {
+		return criterion;
+	}
+	/**
+	 * @param criterion the criterion to set
+	 */
+	@ManyToOne(targetEntity=Criterion.class)
+	@JoinColumn(name="criterion_id",nullable=false)
+	public void setCriterion(Criterion criterion) {
+		this.criterion = criterion;
+	}
+	/**
+	 * @return the report
+	 */
+	@ManyToOne(targetEntity=Report.class)
+	@JoinColumn(name="report_id",nullable=false)
+	public Report getReport() {
+		return report;
+	}
+	/**
+	 * @param report the report to set
+	 */
+	@ManyToOne(targetEntity=Report.class)
+	@JoinColumn(name="report_id",nullable=false)
+	public void setReport(Report report) {
+		this.report = report;
+	}
+	
+	
+}
diff --git a/YACOSCore/ejbModule/org/yacos/core/evaluation/Report.java b/YACOSCore/ejbModule/org/yacos/core/evaluation/Report.java
new file mode 100644
index 0000000..f37e7dc
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/evaluation/Report.java
@@ -0,0 +1,130 @@
+/**
+ * 
+ */
+package org.yacos.core.evaluation;
+
+import java.util.ArrayList;
+import java.util.Collection;
+
+import javax.persistence.Entity;
+import javax.persistence.FetchType;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.ManyToOne;
+import javax.persistence.OneToMany;
+
+import org.yacos.core.article.Article;
+import org.yacos.core.users.User;
+
+/**
+ * @author christiancorsano
+ *
+ */
+@Entity
+public class Report {
+	@Id
+	@GeneratedValue(strategy=GenerationType.AUTO)
+	private Integer id;
+	private String commentPCMember;
+	private String commentAuthor;
+	@OneToMany(targetEntity=Rating.class,mappedBy="report",fetch=FetchType.EAGER)
+	private Collection<Rating> ratings;
+	@ManyToOne(targetEntity=User.class)
+	@JoinColumn(name="referee_id",nullable=false)
+	private User referee;
+	@ManyToOne(targetEntity=Article.class)
+	@JoinColumn(name="article_id",nullable=false)
+	private Article article;
+	/**
+	 * @return the id
+	 */
+	@Id
+	public Integer getId() {
+		return id;
+	}
+	/**
+	 * @param id the id to set
+	 */
+	@Id
+	public void setId(Integer id) {
+		this.id = id;
+	}
+	/**
+	 * @return the commentPCMember
+	 */
+	public String getCommentPCMember() {
+		return commentPCMember;
+	}
+	/**
+	 * @param commentPCMember the commentPCMember to set
+	 */
+	public void setCommentPCMember(String commentPCMember) {
+		this.commentPCMember = commentPCMember;
+	}
+	/**
+	 * @return the commentAuthor
+	 */
+	public String getCommentAuthor() {
+		return commentAuthor;
+	}
+	/**
+	 * @param commentAuthor the commentAuthor to set
+	 */
+	public void setCommentAuthor(String commentAuthor) {
+		this.commentAuthor = commentAuthor;
+	}
+	/**
+	 * @return the referee
+	 */
+	@ManyToOne(targetEntity=User.class)
+	@JoinColumn(name="referee_id",nullable=false)
+	public User getReferee() {
+		return referee;
+	}
+	/**
+	 * @param referee the referee to set
+	 */
+	@ManyToOne(targetEntity=User.class)
+	@JoinColumn(name="referee_id",nullable=false)
+	public void setReferee(User referee) {
+		this.referee = referee;
+	}
+	/**
+	 * @return the article
+	 */
+	@ManyToOne(targetEntity=Article.class)
+	@JoinColumn(name="article_id",nullable=false)
+	public Article getArticle() {
+		return article;
+	}
+	/**
+	 * @param article the article to set
+	 */
+	@ManyToOne(targetEntity=Article.class)
+	@JoinColumn(name="article_id",nullable=false)
+	public void setArticle(Article article) {
+		this.article = article;
+	}
+	
+	public void addRating(Rating rating){
+		ratings.add(rating);
+	}
+	
+	/**
+	 * @return the ratings
+	 */
+	@OneToMany(targetEntity=Rating.class,mappedBy="report")
+	public Collection<Rating> getRatings() {
+		return ratings;
+	}
+	/**
+	 * @param ratings the ratings to set
+	 */
+	@OneToMany(targetEntity=Rating.class,mappedBy="report")
+	public void setRatings(ArrayList<Rating> ratings) {
+		this.ratings = ratings;
+	}
+	
+}
diff --git a/YACOSCore/ejbModule/org/yacos/core/users/IUsersManager.java b/YACOSCore/ejbModule/org/yacos/core/users/IUsersManager.java
new file mode 100644
index 0000000..ab9da89
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/users/IUsersManager.java
@@ -0,0 +1,13 @@
+package org.yacos.core.users;
+
+import java.util.Collection;
+
+import javax.ejb.Remote;
+
+@Remote
+public interface IUsersManager {
+	public Collection<User> getUsers();
+	public void addUser(User user);
+	public void removeUser(User user);
+	public User getUser(String login);
+}
diff --git a/YACOSCore/ejbModule/org/yacos/core/users/Role.java b/YACOSCore/ejbModule/org/yacos/core/users/Role.java
new file mode 100644
index 0000000..e4b37dc
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/users/Role.java
@@ -0,0 +1,98 @@
+package org.yacos.core.users;
+
+import javax.persistence.Entity;
+import javax.persistence.EnumType;
+import javax.persistence.Enumerated;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.ManyToOne;
+import org.yacos.core.conferences.Conference;
+import org.yacos.core.users.RoleType.RoleTypeEnum;
+
+/**
+ * An role of a given type (author,chairman,PCmember or referee)
+ * defined for a user and a conference
+ * @author christiancorsano
+ *
+ */
+@Entity
+public class Role {
+	@Id
+	@GeneratedValue(strategy=GenerationType.AUTO)
+	private Integer id;
+	/**
+	 * User for which this role is defined
+	 */
+	@ManyToOne(targetEntity=User.class,optional=false)
+	@JoinColumn(name="user_id",nullable=false)
+	private User user;
+	/**
+	 * Conference for which this role is defined
+	 */
+	@ManyToOne(targetEntity=Conference.class,optional=false)
+	@JoinColumn(name="conference_id",nullable=false)
+	private Conference conference;
+	/**
+	 * The type of this role
+	 */
+	@Enumerated(EnumType.ORDINAL)
+	private RoleTypeEnum type;
+	
+	public Role(RoleTypeEnum type,User user, Conference conference) {
+		super();
+		setType(type);
+		setUser(user);
+		setConference(conference);
+	}
+	/**
+	 * @return the id
+	 */
+	public Integer getId() {
+		return id;
+	}
+	/**
+	 * @param id the id to set
+	 */
+	public void setId(Integer id) {
+		this.id = id;
+	}
+	/**
+	 * @return the user who plays this role
+	 */
+	public User getUser() {
+		return user;
+	}
+	/**
+	 * @param user the user who is to play this role
+	 */
+	public void setUser(User user) {
+		this.user = user;
+	}
+	/**
+	 * @return the conference for which this role is defined
+	 */
+	public Conference getConference() {
+		return conference;
+	}
+	/**
+	 * @param conference the conference for which this role is defined
+	 */
+	public void setConference(Conference conference) {
+		this.conference = conference;
+	}
+	/**
+	 * @return the type of this role
+	 */
+	public RoleTypeEnum getType() {
+		return type;
+	}
+	/**
+	 * @param type the type of this role
+	 */
+	public void setType(RoleTypeEnum type) {
+		this.type = type;
+	}
+	
+}
diff --git a/YACOSCore/ejbModule/org/yacos/core/users/RoleType.java b/YACOSCore/ejbModule/org/yacos/core/users/RoleType.java
new file mode 100644
index 0000000..1384462
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/users/RoleType.java
@@ -0,0 +1,52 @@
+/**
+ * 
+ */
+package org.yacos.core.users;
+
+/**
+ * @author christiancorsano
+ *
+ */
+public class RoleType {
+	// TODO : see what we do with this class
+	public enum RoleTypeEnum {
+		AUTHOR,CHAIRMAN,PCMEMBER,REFEREE
+	}
+	/**
+	 * Author constant role
+	 */
+	static public final RoleType author = new RoleType("author");
+	/**
+	 * Chairman constant role
+	 */
+	static public final RoleType chairman = new RoleType("chairman");
+	/**
+	 * PCMember constant role
+	 */
+	static public final RoleType PCmember = new RoleType("PCmember");
+	/**
+	 * Referee constant role
+	 */
+	static public final RoleType Referee = new RoleType("referee");
+	
+	/**
+	 * Name of this role type
+	 */
+	private String name;
+	
+	/**
+	 * Private constructor : used to instanciate the constants
+	 * @param name Name of the new RoleType
+	 */
+	private RoleType(String name){
+		this.name = name;
+	}
+	
+	/**
+	 * Return the name of this RoleType
+	 * @return
+	 */
+	public String getName() {
+		return this.name;
+	}
+}
diff --git a/YACOSCore/ejbModule/org/yacos/core/users/User.java b/YACOSCore/ejbModule/org/yacos/core/users/User.java
new file mode 100644
index 0000000..f97a3ea
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/users/User.java
@@ -0,0 +1,159 @@
+package org.yacos.core.users;
+
+import java.io.Serializable;
+import java.util.Collection;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.OneToMany;
+
+import org.yacos.core.conferences.Conference;
+
+
+/**
+ * A unique User of the system.
+ * The user is registered globally in the application and would be able to get different roles for
+ * different conferences.
+ * @author christiancorsano
+ *
+ */
+@Entity
+public class User implements Serializable{
+	/**
+	 * Unique login of the user
+	 * Is used to identify the user, should be unique and can't be modified
+	 */
+	@Id
+	private String login;
+	/**
+	 * Password : used for authentication purpose only, is only writable
+	 */
+	private String password;
+	/**
+	 * First Name of the user
+	 */
+	private String firstName;
+	/**
+	 * Last name of the user
+	 */
+	private String lastName;
+	/**
+	 * Organization or lab the user belongs to
+	 */
+	private String organization;
+	/**
+	 * Active email (has to be used frequently) of the user
+	 */
+	private String email;
+	/**
+	 * Roles for this user
+	 */
+	@OneToMany(targetEntity=Role.class,mappedBy="user")
+	private Collection<Role> roles;
+	
+	public User(String login, String password, String firstName,
+			String lastName, String organization, String email,
+			Collection<Role> roles) {
+		super();
+		this.login = login;
+		this.password = password;
+		this.firstName = firstName;
+		this.lastName = lastName;
+		this.organization = organization;
+		this.email = email;
+		this.roles = roles;
+	}
+
+	public User() {
+		
+	}
+	
+	
+	
+
+	@Id
+	public String getLogin() {
+		return login;
+	}
+	
+	public void setPassword(String password) {
+		this.password = password;
+	}
+
+	public String getFirstName() {
+		return firstName;
+	}
+
+	public void setFirstName(String firstName) {
+		this.firstName = firstName;
+	}
+
+	public String getLastName() {
+		return lastName;
+	}
+
+	public void setLastName(String lastName) {
+		this.lastName = lastName;
+	}
+
+	public String getOrganization() {
+		return organization;
+	}
+
+	public void setOrganization(String organization) {
+		this.organization = organization;
+	}
+
+	public String getEmail() {
+		return email;
+	}
+
+	public void setEmail(String email) {
+		this.email = email;
+	}
+	
+	public void addRole(Role role){
+		roles.add(role);
+	}
+	
+	public void addRoleForConference(RoleType roleType, Conference conference){
+		if(! hasRoleForConference(roleType,conference)){
+			
+		} else {
+			// TODO : declare and throw an exception
+		}
+	}
+	
+	public boolean hasRoleForConference(RoleType roleType, Conference conference){
+		// TODO
+		return false;
+	}
+
+	@OneToMany(targetEntity=Role.class,mappedBy="user")
+	public Collection<Role> getRoles(){
+		return roles;
+	}
+
+	/**
+	 * @return the password
+	 */
+	public String getPassword() {
+		return password;
+	}
+
+	/**
+	 * @param login the login to set
+	 */
+	public void setLogin(String login) {
+		this.login = login;
+	}
+
+	/**
+	 * @param roles the roles to set
+	 */
+	@OneToMany(targetEntity=Role.class,mappedBy="user")
+	public void setRoles(Collection<Role> roles) {
+		this.roles = roles;
+	}
+	
+}
diff --git a/YACOSCore/ejbModule/org/yacos/core/users/UsersManager.java b/YACOSCore/ejbModule/org/yacos/core/users/UsersManager.java
new file mode 100644
index 0000000..d24e1bd
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/users/UsersManager.java
@@ -0,0 +1,33 @@
+/**
+ * 
+ */
+package org.yacos.core.users;
+
+import java.util.Collection;
+
+/**
+ * @author christiancorsano
+ *
+ */
+public class UsersManager {
+	public Collection<User> getUsers(){
+		// TODO
+		return null;
+	}
+	
+	/**
+	 * Adds a user into the system
+	 * @param user
+	 */
+	public void addUser(User user){
+		// TODO
+	}
+	
+	/**
+	 * Removes a user from the system
+	 * @param user
+	 */
+	public void removeUser(User user){
+		// TODO
+	}
+}
diff --git a/YACOSCore/ejbModule/org/yacos/core/users/UsersManagerBean.java b/YACOSCore/ejbModule/org/yacos/core/users/UsersManagerBean.java
new file mode 100644
index 0000000..3212ace
--- /dev/null
+++ b/YACOSCore/ejbModule/org/yacos/core/users/UsersManagerBean.java
@@ -0,0 +1,48 @@
+/**
+ * 
+ */
+package org.yacos.core.users;
+
+import java.util.Collection;
+
+import javax.ejb.Stateless;
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.persistence.Query;
+
+/**
+ * @author christiancorsano
+ *
+ */
+@Stateless
+public class UsersManagerBean implements IUsersManager{
+	@PersistenceContext
+	EntityManager em;
+	
+	@SuppressWarnings("unchecked")
+	public Collection<User> getUsers(){
+		Query query = em.createNativeQuery("from User", User.class);
+		return query.getResultList();
+	}
+	
+	/**
+	 * Adds a user into the system
+	 * @param user
+	 */
+	public void addUser(User user){
+		em.persist(user);
+	}
+	
+	/**
+	 * Removes a user from the system
+	 * @param user
+	 */
+	public void removeUser(User user){
+		User persistedUser = em.find(User.class, user.getLogin());
+		em.remove(persistedUser);
+	}
+
+	public User getUser(String login) {
+		return em.find(User.class, login);
+	}
+}