Sentiment analysis is the computational study of opinions, sentiments, and emotions expressed in texts. The basic task of sentiment analysis is to classify the polarity of the existing texts in documents, sentences, or opinions. Polarity has meaning if there is text in the document, sentence, or the opinion has a positive or negative aspect. In this study, classification of the polarity in sentiment analysis using machine learning techniques, that is Naïve Bayes classifier. Criteria for text classification decisions, learned automatically from learning the data. The need for manual classification is still required because training the data derived from manually labeling, the label (feature) refers to the process of adding a description of each data according to its category. In the process of labeling, feature selection is used and performed by chi-square feature selection, to reduce the disturbance (noise) in the classification. The results showed that the frequency of occurrences of the expected features in the true category and in the false category have an important role in the chi-square feature selection. Then classification breaking news by Naïve Bayes classifier obtained an accuracy of 83% and a harmonic average of 90.713%.

Fuzzy logic is a way to map an input space into an output space. The basic of fuzzy logic is fuzzy set theory. In the fuzzy set theory, the role of membership degree is important to determine the presence of elements in a set. Membership degree is the fundamental feature of reasoning in fuzzy logic. There are several methods that are often used in solving fuzzy inference system, one of them is fuzzy Sugeno method. The aim of this research is applications of fuzzy methods is to forecast to determine the selling price of used motorcycles. In determining the selling price of used motorcycles, there are several things that need to be considered, namely : the production year of the motorcycles, the physical condition of the motorcycles, the origin of the license plates, and the purchase price of the motorcycles. The calculation can be done by using Matlab program. The result obtained were then tested using the Mean Absolute Percentage Error (MAPE) by calculating difference between the selling price of dealer minus the selling price of fuzzy Sugeno then divided by the selling price of dealer. From the test result, MAPE value obtained was 5,64% . This indicates that error rate below 10%, so we can say the result of these calculation is considerably accurate.

Joint Life insurance is an insurance that covered two individuals in one policy. The purpose of this research is to determine and to compare the reserve value of Joint Life insurance using New Jersey method and Prospective method with and without New Jersey method. The method that used in this research are New Jersey method, the participants of this assurance is a couple of husband and wife between 45 and 40 years old with 30 years period, interest levels at 6,5%. The results of this represent reserve value with New Jersey method always smaller, and the reserve value in the 30 years period have the same result using New Jersey method and Prospective method.

This work is directed to forecast the number of foreign visitors come to tourist’s destinations at Badung regency, Province of Bali. Using visit historical data for period January 2000 to February 2015, Markov Transition Matrix and Fuzzy Triangular Number are applied to represent fuzzy logical relationship group and member function in fuzzy model, respectively.  The results showed the in-sample forecasting accuracy for our fuzzy model as much as 2,48 percent. To validate the model, we found the average forecasting error rate for five consecutive months (March – July 2015) as much as 2,70 percent.

This research is aimed to analyze the effect of domestic tourists’ satisfaction towards their intention to revisit destinations at Badung Regency, Province of Bali by using hierarchical construct modeling. Data from 75 local tourists were collected in July through December 2015 and were used to model this causal relationship.  In our model, destination attributes, tourist’s facilities, and destination accessibilities were positioned as the second-order constructs and proposed have effect on tourists’ satisfaction.  Futhermore, satisfaction – in turns – is proposed affects tourist intention to revisit.  We found destination attributes significantly affect tourist satisfaction with its causal value is 0.410 and this satisfaction significantly affects their intention to revisit tourism destinations at Badung Regency with path value as much as 0.764.