The purposes of this research are 1) to study the demographic characteristics and behavior in purchasing via line application and 2) to compare the level of satisfaction in purchasing via line application for an open chat consumer group Kheha Thanee 4 Village Bangkok. This study applied quantitative methods and the research instrument was an online questionnaire. The sample group of this study consisted of 306 consumers members of the open chat consumer group Kheha Thanee 4 Village Bangkok. The data were analyzed by frequency percentage mean standard deviation and the researcher tested hypothesis with T Test and One Way ANOVA. The research findings were as follows:

The conductor of an order is the largest ideal of the ring of integers of a field which is contained in the order. In this paper we characterize conductors in quartic number fields whose norm is a power of unramified prime.

In this research we introduce the notions of fuzzy d-subalgebra and fuzzy d-ideal of a d-algebra with respect to a triangular norm. Then we investigate some related properties

Development of Software Management System for Laundry Shop. The Object is to use the theory in database course to develop the online database and to use the computer technology to manage the laundry system for increasing the effectiveness for working. The system was developed as the web application with PHP and Bootstrap and MySQL is employed to act as the database. The system can show the customer status and price to the website and smartphone.