Onset of most mental disorders appears between ages 15 and 24. However, many students who need to get appropriate psychological treatments are not clearly aware their mental disorder. Thus, early detection of depression is a critical part of improving the efficacy of mental health management. In order to recognize depression at an early stage, I am looking to explore novel sensing technologies and modeling approaches. For example, I am developing a UV sensor-enabled wristband to estimate students’ vitamin D levels.


Interruptions while driving, such as text messages, can be quite perilous. These distractions increase driver workload and reduce performance on the primary driving task. Being able to identify when a driver is susceptible to interruptions is critical for building systems that can mediate these interruptions. In this project, I develop a driving sensing platform that integrates four different Bluetooth sensors and one Bluetooth-LE haptic feedback actuator. Preliminary results of the project demonstrate the effectiveness of the platform.


SMART BAND | 2013 - 2015

As the potential of wristband technologies is still being explored, LG created Smart Band to be a more effective and convenient device to manage user's health status. I developed firmware, device drivers, and Bluetooth-LE functions for a custom-designed ultra low power microprocessor in the Smart Band project. The Final outcome of the project is not commercialized, but utilized as an advanced wearable prototype inside LG Electronics. The form factor of the device is similar to the image on the left.

IOT SENSOR | 2013 - 2015

Imagine a drawer that contains your most important belongings. I have developed IoT(Internet of Things) sensors that can be placed into the drawer, and protect against unauthorized access using vibration monitoring function. My IoT research outcomes can make any mundane appliance “smarter.” In IFA 2015, LG introduced a slightly different version of my research outcome, which called Smart ThinQ Sensor.


EARPULSE | 2011 - 2013

Since previous heart rate sensors have been uncomfortable and restricting on everyday use, we developed a novel heart rate (HR) monitoring approach in which we measure the pressure variance of the surface of the ear canal. In order detect pressure variance in a comfortable way, a scissor-shaped apparatus and a customized piezoelectric film sensor were designed for high wearability. In the proposed device, the film sensor converts in-ear pulse waves (EPW) into electrical current, and the circuit module enhances the EPW and suppresses noise. A real-time algorithm performs morphological conversions and knowledge-based rules are used to detect EPW peaks.

Video Paper More

BABY CARE SYSTEM | 2009 - 2012

More than 3 million children experience an unintentional home accident every year. This project presents a child activity recognition approach that prevents child accidents such as falls. These injuries can be prevented by wearable sensors and activity recognition algorithms. The overall accuracy of our activity recognition was 98.43% using only a single-wearable triaxial accelerometer sensor and a barometric pressure sensor with a support vector machine.

Paper1 Paper2 More


Recognition of sleep patterns is very important for numerous reasons such as the treatment of sleep disorders and the assessment of sleep quality. DreamSleep, a wearable sleep sensor, is developed to monitor sleep patterns in a more comfortable way. It is composed of two different parts: i) a wearable sleep sensor and ii) an Android application. The wearable sleep sensor is to be attached to the user’s abdominal area. Then it senses user movements and snoring sounds to recognize sleep status. Main features of the application include visualization of sleep patterns, database for sensing data, and Bluetooth communication.

Video More


Drug information should be easily accessible at any time. For these purpose, I developed a mobile application, DrugInfo, that includes a drug information database jointly developed by BIT Computer and Seoul National University in South Korea. It contains the latest information on pharmaceutical products including drug usage guide, patient education on disease, drug identification by its image, drug administration for pregnant women, and scientific information of drugs.

Google Play


If a patient has metabolic syndrome, he needs to provide a large amount of personal information related to his disease periodically. Unfortunately, these recurrent questionnaires are not only making him feel uncomfortable, but also becoming prohibitive. To solve the challengeable problems, we attempted to research numerous approaches with respect to the diagnosis and treatment of metabolic syndrome with Ajou University Hospital. As a result of this research, we developed a specialized ‘Well-being index model’ for treatments of metabolic syndrome, and also designed a context-aware system to deploy the index model in the real world.

Video Paper Flyer


Developmental disabilities such as Mucopoly-saccharidoses (MPS) require minute-to-minute, burdening care on the part of the parents. Often, one of the parents has to be dedicated 100%, 24/7 to support and sustain their child’s life. To enhance children’s cognitive ability in expressing some of their desires, we designed a simple DVD controller in a specific form factor suitable to MPS children. Our design was participatory, allowing one family with MPS children to provide guidelines. TouchView is intended to provide intuitive way for MPS children to express their wishes and desires of watching a particular movie.



A ubiquitous environment such as the Gator Tech Smart House (GTSH) provides services that incorporate many sensors and smart appliances. These smart objects lend themselves to other services and allow interaction with users. However, many mundane objects do not have such capabilities. In this project, we demonstrate the SmartPlug, a tool deployed at the GTSH that integrates everyday appliances such as lamps and fans into the smart house through power outlets and switches. We show a design of the SmartPlug and the automatic integration process through the Atlas middleware and the Device Description Language (DDL).

Paper Guide


To promote personal health for the elderly and the disabled, and to support independent living at reasonable cost, it is agreeable that a home-based sensor network that collects various data and vital signs of the residents is a promising approach. In this project, networked MEMS accelerometer sensors are considered as a superior technology for localizing footstep source and computing correlation between the level of energy expenditure and the level of floor vibration.



In a ubiquitous environment, system makes their own decision without or with minimized user interaction to provide required services to users. To fulfill this requirement the system needs to collect the proper information of surroundings and define how to react to the changes based on found information autonomously. To achieve this process, the system includes three basic components that are sensing infrastructure, context aware or intelligent decision, and smart services. Main purpose of this research is how to enable this process efficiently and suggest the way of developing smart space.

Video Paper

SMART CUP | 2006

Since medication taking is such a routine and mundane behavior, self-monitoring of medication taking is an onerous and difficult task. In order to manage the task more effectively and efficiently, I developed a sensor- augmented cup, which called SmartCup. This cup consists of a tilt sensor that can detect if the cup is shaking and an implemented OLED display to notify medication alarms. A central server manages a user’s medication schedule, and sends an alarm signal to the SmartCup. Then the SmartCup keeps sensing its shaking status to recognize user’s intake motion.


In class of Sensor and Actuator Engineering in 2006, I designed and implemented an augmented glove that can recognize user’s hand gestures by using two flex sensors and two gyro sensors. A PC application gathered real-time sensing data through Bluetooth communication and fused the two different sensing data to control a mouse cursor.