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Wŏnju, South Korea

Kang J.A.,Electronics and Telecommunications Research Institute | Park N.I.,National Forensic Service NFS | Kim H.K.,Gwangju Institute of Science and Technology | Lee S.R.,Mokpo National University
International Journal of Distributed Sensor Networks | Year: 2015

In this paper, an adaptive speech streaming method is proposed to improve the perceived speech quality (PSQ) of voice over wireless multimedia sensor network (WMSNs). First of all, the proposed method estimates the PSQ of the received speech data under different network conditions that are represented by the packet loss rates (PLRs). Simultaneously, the proposed method classifies the speech signal as either an onset or a nononset frame. Based on the estimated PSQ and the speech class, it determines an appropriate bit rate for the redundant speech data (RSD) that are transmitted with the primary speech data (PSD) to help reconstruct the speech signals of any lost frames. In particular, when the estimated PLR is high, the bit rate of the RSD should be increased by decreasing that of the PSD. Thus, the bandwidth of the PSD is changed from wideband to narrowband, and an artificial bandwidth extension technique is applied to the decoded narrowband speech. It is shown from the simulation that the proposed method significantly improves the decoded speech quality under packet loss conditions in a WMSN, compared to a decoder-based packet loss concealment method and a conventional redundant speech transmission method. © 2015 Jin Ah Kang et al.


Jang T.-S.,CHA Medical University | Zhang H.Y.,Yeungnam University | Kim G.J.,Yeungnam University | Kim D.W.,National Forensic Service NFS | And 5 more authors.
Archives of Pharmacal Research | Year: 2012

Fatty acid synthase (FAS) is considered as a novel drug target for the development of anticancer and anti-obesity agents. Bioassay-guided fractionation of a n-hexane-soluble extract prepared from the roots of Salvia miltiorrhiza Bunge (Labiatae), using an in vitro enzyme assay, led to the isolation of five abietane diterpenoids: 15,16-dihydrotanshinone I (1), cryptotanshinone (2), tanshinone I (3), tanshinone IIA (4), and dansenspiroketallactone (5). Compounds 1-5 were tested for their in vitro FAS inhibitory activity and, except for compound 5 (IC 50 > 100 μM), compounds 1-4 inhibited the enzyme activity with IC 50 values ranging from 12.0 to 30.3 μM. Our findings may be partially related to the anticancer activity of abietane diterpenoids from the plant, suggesting a further study on the anticancer potential of tanshinone derivatives.


Jeong S.H.,Gwangju Institute of Science and Technology | Chun C.J.,Gwangju Institute of Science and Technology | Park N.I.,National Forensic Service NFS | Kim H.K.,Gwangju Institute of Science and Technology | Kim H.K.,City University of New York
Proceedings - 7th International Conference on Signal Processing, Image Processing and Pattern Recognition, SIP 2014 | Year: 2014

In this paper, we address the issue of the real-time implementation of an artificial stereo audio extension method that provides stereophonic audio from a mono audio source. First, the floating-point arithmetic programming of the method is performed. Then, the computationally complex parts of the floating-point operations are converted into fixed-point operations to allow them to operate in real time. The performance of a real-time implementation is evaluated by measuring the processing time and root mean square (RMS) value. Consequently, it is shown that partial fixed-point arithmetic programming reduces the processing time by 48.7%, with an RMS value of-90.50 dB, compared to the floating-point arithmetic programming. © 2014 IEEE.


Cho Y.,Gwangju Institute of Science and Technology | Kong Y.,Gwangju Institute of Science and Technology | Sa S.,Seoul Institute | Choi C.,Seoul Institute | And 4 more authors.
Fire Technology | Year: 2015

A fire took place in an indoor shooting range in Pusan, Korea, causing 15 deaths and 1 injury. To determine the cause of the fire, field investigation and laboratory analysis were conducted, and the point of ignition was determined through closed-circuit television (CCTV) imagery. Residues of ball powder, balloon, and stray bullet were found at the point of ignition. Moreover, the polyurethane slabs installed for sound absorption on the walls and ceiling surrounding the point of origin were found to lack any flame resistance. In tests of gunpowder ignition on the surface of the sound absorbers, the material ignited readily and the fire spread rapidly. Through analysis of CCTV at the time of ignition, any source of ignition related to human intervention could be ruled out. Considering the fact that ignition started immediately after shooting and the rubber plate for stray bullet protection had fallen off, we conclude that the most probable scenario is that a stray bullet landed on the sound absorber at the point of origin and ignited ball powder accumulated there, thus starting the fire. As a result of shooting 50 rounds of bullets, most bullet fragments dropped within 2 m of the bullet trap whereas two stray bullets reached 4.6 m and 1.3 m from the point of ignition. It was revealed that people at the indoor shooting range did not have sufficient time to evacuate. Although the fire lasted for a short time, victims were exposed to high temperatures, making visual identification difficult. © 2014, Springer Science+Business Media New York.

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