• Advances in aircraft and spacecraft science
• /
• v.1 no.1
• /
• pp.27-41
• /
• 2014

An active flow control technique based on "smart-tabs" is proposed to delay flow separation on a circular cylinder. The actuators are retractable and orientable multilayer piezoelectric tabs which protrude perpendicularly from the model surface. They are mounted along the spanwise direction with constant spacing. The effectiveness of the control was tested in pre-critical and in post-critical regime by evaluating the effects of several control parameters of the tabs like frequency, amplitude, height, angular position and plate incidence with respect to the local flow. Measurements of the mean static pressure distribution around the cylinder were used to estimate the pressure drag coefficient. The maximum drag reduction achieved in the pre-critical regime was of the order of 30%, whereas in the post-critical regime was about 10%, 3% of which due to active forcing. Furthermore, pressure fluctuation measurements were performed and spectral analysis indicated an almost complete suppression of the vortex shedding in active forcing conditions.

• Proceedings of the Korean Information Science Society Conference
• /
• 2011.06c
• /
• pp.258-261
• /
• 2011

Living in the age of information people face problems related to information overload. Information is easy to produce, store and distribute through various communication channels, one of which is emails. With the appearance of the mobile devices, such as smart phones and tabs, people can have access to email inbox at any moment of time from everywhere. In this paper we present information extraction system with a specific goal of extracting meeting location from the announcement of seminar or conference. We apply a machine learning method (conditional random fields, CRF), train the system using annotated corpus of seminar and conference announcements and validate results by applying various extracted correction rules and patterns. Furthermore, we normalize extracted location, and reference using geo-coding databases, OpenStreetMap and Wikipedia resources to determine real geographical coordinates.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.10a
• /
• pp.507-509
• /
• 2013

This paper covers the individual with mild autistic disorder complementary and alternative communication Support program by using Android. The complementary and alternative communication is the communicative system to help handicapped people who have problems with colloquial and non-colloquial communication. In this research, we will introduce the communication manner of autistic disorder, the method of how to measure the language disabled people's selection and frequency of the words, and the basic training method of Autism people's communication ways. In this paper, we developed complementary and alternative communication system which used language representative method to encourage language disabled people to study on communication in effective way. We utilized 'TTS technology' to enable handicapped people delivering their mind with the voice; moreover, by listening their voice by themselves, we accelerated their studies on communications. In addition, by offering 'Painting function', we promoted handicapped people to deliver their purpose widely and efficiently. Also, we built the smart system in 'Painting function' to collect frequency and educated degree data from the users by using this function, we can analyze the percentage of conscious and unconscious communication way of Autism cases to help them.