Soo Jun Park

Real-time elderly activity monitoring system based on a tri-axial accelerometer.

Purpose. The purpose of this study is to develop an automatic human movement classification system for the elderly using single waist-mounted tri-axial accelerometer. Methods. Real-time movement classification algorithm was developed using a hierarchical binary tree, which can classify activities of daily living into four general states: (1) resting state such as sitting, lying, and standing; (2) locomotion state such as walking and running; (3) emergency state such as fall and (4) transition state such as sit to stand, stand to sit, stand to lie, lie to stand, sit to lie, and lie to sit. To evaluate the proposed algorithm, experiments were performed on five healthy young subjects with several activities, such as falls, walking, running, etc. Results. The results of experiment showed that successful detection rate of the system for all activities were about 96%. To evaluate long-term monitoring, 3 h experiment in home environment was performed on one healthy subject and 98% of the movement was successfully classified. Conclusions. The results of experiment showed a possible use of this system which can monitor and classify the activities of daily living. For further improvement of the system, it is necessary to include more detailed classification algorithm to distinguish several daily activities.

Sensitivity response to coating material thickness for an optical resonant reflective biosensor based on a guided mode resonance filter

Sensitivity is a very important parameter for biosensor applications. We have numerically and experimentally studied the sensitivity and linewidth responses of optical resonant reflective biosensors to the thickness of high refractive index materials coating the grating layer used to create a guided mode. Zero sensitivity, which may create serious problems in biosensors, is obtained when the coating material has a relatively low refractive index and a thin coating thickness (near the cutoff condition in which a high index layer is no longer capable of acting as a waveguide). The sensitivity and linewidth are greatly influenced by the thickness of the coating material. The thickness also has an optimal state, which is a very important factor for designing highly sensitive optical resonant reflective biosensors using a guided mode resonance filter.

EPITRANS: A Database that Integrates Epigenome and Transcriptome Data

Epigenetic modifications affect gene expression and thereby govern a wide range of biological processes such as differentiation, development and tumorigenesis. Recent initiatives to define genome-wide DNA methylation and histone modification profiles by microarray and sequencing methods have led to the construction of databases. These databases are repositories for international epigenetic consortiums or provide mining results from PubMed, but do not integrate the epigenetic information with gene expression changes. In order to overcome this limitation, we constructed EPITRANS, a novel database that visualizes the relationships between gene expression and epigenetic modifications. EPITRANS uses combined analysis of epigenetic modification and gene expression to search for cell function-related epigenetic and transcriptomic alterations (Freely available on the web at http://epitrans.org).

A Protein Structure Retrieval System Using 3D Edge Histogram

This paper proposes a novel protein structure descriptor (or representation) and its application for structure comparison. Since the functions of protein may come from its structure, the method of measuring structural similarities between two proteins can infer their functional closeness. In this paper, we have developed a novel descriptor (3D edge histogram) to compare the structures of proteins. The 3D edge histogram is a local distribution of bonds between the atoms in a protein. We have designed and implemented a protein structure retrieval system based on the 3D edge histogram to demonstrate that it could be effective in protein structure comparison. In this system, principal component analysis for aligning, voxelization for volume generation, quantization, 3D edge extraction, and comparison of 3D edge histogram are performed. The protein structure retrieval system using the 3D edge histogram shows fast retrieval with relatively precise results. It can be used for pre-screening purposes with a huge database.

Design considerations for pico-projector based on LCoS and 3-LEDs

In this paper, two considerations were presented for designing pico-projector based-on LCoS panel and LED. To have a clear picture, LED duty cycle has to be less than 50% of whole possible LED illumination times. And, a constant current circuit is needed to maintain a white balance of picture.

Mobile personal sports activity management app

In order to expect the effect of promotion of health through the activation of personal sports activity, scientific data management based on quantification of personal sports activity is needed. However there is a lack of integrated management systems of various sport activities as well as motivating factor for ongoing participation in sports activity. This paper proposes an effective integration and management method of the personal sports activity data. The data can be used for the certification of personal sports activity for personal use in the future. The personal sports activity management system has developed with mobile app.