• The Journal of the Acoustical Society of Korea
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• v.21 no.3
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• pp.293-303
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• 2002

This paper implements optimized Time Scale Modification (TSM) system using ITU G.729 speech decoder and Dual SOLA algorithm. The proposed system assume 8 Kz sampling rate, 80 samples/frame input speech from the ITU G.729 speech Decoder and the TSM (Time Scale Modification) feature of Dual SOLA produces the high quality output speech that was slow-down or speed up as a user's choice. Especially, the proposed Optimized Dual SOLA base on various simulations and theoretical analysis, and the additional interpolation procedure of the speech makes it possible to setup high performance integrated TSM system at the maximum time scale modification rate. The system performance is analyzed and verified with various input speech and playback speed.

• Journal of radiological science and technology
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• v.46 no.5
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• pp.417-425
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• 2023

The glomerular filtration rate (GFR) has been the subject of much research as a key indicator for diagnosing, treating, and monitoring kidney function. The gamma camera method (Gates method) is simple and allows simultaneous acquisition of GFR and renal scintigraphy for each kidney, however its accuracy is inferior. This study aimed to investigate changes in GFR depending on how region of interest (ROI) are set up, which is one of many factors influencing accuracy. GFR was calculated by setting the ROI for each phase of the image acquisition time (Gates-1: 0~1 minutes, Gates-2: 1~3 minutes, Gates-3: 3~27 minutes), and statistical significance was verified based on probability value 0.05 through ANOVA analysis. While there was no statistically significant difference among results from Gates-1, 2, 3 (p=0.481>0.05), overall results from the Gates method tended to overestimate compared to those from the multiple blood sampling-dual exponential (MBSDE) method. When comparing averages between phases, results from Gates-2 were most similar to those from the MBSDE method. Moreover, paired t-test p-values between MBSDE method and phases were as follows Gates-1: 0.021 (p<0.05), Gates-2: 0.280 (p>0.05), and Gates-3: 0.164 (p>0.05) indicating that only Gates-1 had statistically significant differences compared with MBSDE method. Thus, setting ROI around 2~3 minutes is calculated can aid in accurately determining GFR when Gates Method.

• Journal of information and communication convergence engineering
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• v.13 no.4
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• pp.235-240
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• 2015

A decimation chain for multi-standard reconfigurable radios is presented for 900-MHz and 1,900-MHz dual-band cellular standards with a data interpolator based on the Lagrange method for adjusting the variable data rate to a fixed data rate appropriate for each standard. The two proposed configurations are analyzed and compared to provide insight into aliasing and the signal bandwidth by means of a newly introduced measure called interpolation error. The average interpolation error is reduced as the ratio of the sampling frequency to the signal BW is increased. The decimation chain and the multi-rate analog-to-digital converter are simulated to compute the interpolation error and the output signal-to-noise ratio. Further, a method to operate the above-mentioned chain under a compressed mode of operation is proposed in order to guarantee continuous packet connectivity for inter-radio-access technologies. The presented decimation chain can be applied to LTE, WCDMA, GSM multi-mode multi-band digital front-end which will ultimately lead to the software-defined radio.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.2
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• pp.196-200
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• 1987

The following methods are proposed for implementing digital dual tone multi-frequency (DTMF) receiver: using infinite impulse response(IIR) digital filters, period-counting algorithm, discrete Fourier transform(DFT), and fast Fourier transform(FFT)[2]. The PARCOR(Partical Correlation) analysis method which has been widly used in the speech signal processing area is applied to the dual tone multi-frequency(DTMF) signal detection. This method is easy to implement digitally and stronger to digit simulation of speech than any other methods proposed up to date. Since sampling rate of 4KHz is used in the DTMF receiver for the detection of input DTMF signal originally sampled at 8KHz, it effects two times higher multiplexing efficiency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.4
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• pp.373-385
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• 1987

The scaled WDF should be optimized from the point of view of dynamic range. Transformer scaling method is attempted to maximize the dynamic range by equalizing the gains in the different nodes of the WDF. In this paper, the dual network and different frequencies are used to study the effects of different topology and of sampling frequency. Comparing with the unscaled WDF, the most significant observation is that the SNR is improved in the range of 7 to 35 dB in the WDF scaled by the trasnsformer scaling method. In addition, the SNR shows a continuous drop with the increase of sampling frequency, but scaling effects seem to decrease the rate at which the SNR drop.

• Research in Community and Public Health Nursing
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• v.6 no.1
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• pp.84-97
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• 1995

There is a widespread concern that women's increasing involvement in dual role (job plus family role) may harm their physical health. Longevity of women is longer than that of men. By contrast, prevalence rate is higher in women than men, and No. of prevalence days, No. of days in bed and No. of days with treatment are more in women. Generally, women live longer, but women are worse in health status than men. Rate of labor participation in women is increasing gradually in Korea. This study presents an analysis of the relationships between employment. marital status and health for both Korean women and men to examine how women's increasing involvements in dual role affect their physical health. The data used in this analysis were collected by The National Statistical Office in the spring of 1992. Households, which were sampled by using a three-stage stratified cluster sampling method, were interviewed. Response rate was 99.43%. Of these, student or widowed or divorced people were excluded. 47,552 women and men aged 21-50 were available for the analysis. Health status was measured by self-assessed health status (1=excellent, 5=poor), No. of prevalent days, No. of days with treatment, and No. of days in bed in two previous weeks. And control variables are age, and education. Research findings are as follows : 1. Men have better self-rated health, fewer prevalent days, fewer days in bed, and fewer days with treatment than women. 2. The employed are more healthier than the non-employed. 3. Unmarried people are more healthier than married people. 4. Interaction effects of sex, marital status, employment are significant. This finding shows that effects of empolyment, marital status on health status is not same for women and men. 5. For male, employed people are more healthier than non-employed people. Unmarried people are more healthier than married people. This differences are significant. For female, The employed are more healthier than the non-employed. However, no differences are noticed between the married and the unmarried in health status. In conclusion, there is no evidence that women's involvements in dual role affect their physical health negatively.

• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.506-508
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• 1998

In this paper, the optimal digital redesign is studied within the framework of fuzzy systems and dual-rate sampling control theory. An equivalent fast-rate discrete-time state-space model of the continuous-time system is constructed by using fuzzy inference systems. To obtain the optimal feedback gains developed in the continuous-time system, the constructed fuzzy system is converted into a continuous-time system. The developed continuous-time control law is converted into an equivalent slow-rate digital control law using the proposed digital redesign method. The digital redesign technique using a fuzzy model is employed to simulate the inverted pendulum dynamics.

• Journal of Sensor Science and Technology
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• v.21 no.5
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• pp.352-358
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• 2012

A sensor network system can be an efficient tool for healthcare telemetry for multiple users due to its power efficiency. One drawback is its limited data size. This paper proposed a real-time application of data compression/decompression method in u-Health monitoring system in order to improve the network efficiency. Our high priority was given to maintain a high quality of signal reconstruction since it is important to receive undistorted waveform. Our method consisted of down sampling coding and differential Huffman coding. Down sampling was applied based on the Nyquist-Shannon sampling theorem and signal amplitude was taken into account to increase compression rate in the differential Huffman coding. Our method was successfully tested in a ZigBee and WLAN dual network. Electrocardiogram (ECG) had an average compression ratio of 3.99 : 1 with 0.24% percentage root mean square difference (PRD). Photoplethysmogram (PPG) showed an average CR of 37.99 : 1 with 0.16% PRD. Our method produced an outstanding PRD compared to other previous reports.

• Smart Structures and Systems
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• v.6 no.5_6
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• pp.731-748
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• 2010

Impact detection and health monitoring are very important tasks for civil infrastructures, such as bridges. Piezoceramic based transducers are widely researched for these tasks due to the piezoceramic material's inherent advantages of dual sensing and actuation ability, which enables the active sensing method for structural health monitoring with a network of piezoceramic transducers. Wireless sensor networks, which are easy for deployment, have great potential in health monitoring systems for large civil infrastructures to identify early-age damages. However, most commercial wireless sensor networks are general purpose and may not be optimized for a network of piezoceramic based transducers. Wireless networks of piezoceramic transducers for active sensing have special requirements, such as relatively high sampling rate (at a few-thousand Hz), incorporation of an amplifier for the piezoceramic element for actuation, and low energy consumption for actuation. In this paper, a wireless network is specially designed for piezoceramic transducers to implement impact detection and active sensing for structural health monitoring. A power efficient embedded system is designed to form the wireless sensor network that is capable of high sampling rate. A 32 bit RISC wireless microcontroller is chosen as the main processor. Detailed design of the hardware system and software system of the wireless sensor network is presented in this paper. To verify the functionality of the wireless sensor network, it is deployed on a two-story concrete frame with embedded piezoceramic transducers, and the active sensing property of piezoceramic material is used to detect the damage in the structure. Experimental results show that the wireless sensor network can effectively implement active sensing and impact detection with high sampling rate while maintaining low power consumption by performing offline data processing and minimizing wireless communication.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.9
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• pp.68-73
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• 2013

In this paper, we proposed a readout circuit of pulse waveform and rate for a U-health system to monitor health condition. For long-time operation without replacing or charging a battery, either pulse waveform or pulse rate is selected as the output data of the proposed readout circuit according to health condition of a user. The proposed readout circuit consists of a simple digital logic discriminator and a dual-mode ADC which operates in the ADC mode or in the count mode. Firstly, the readout circuit counts pulse rate for 4 seconds in the count mode using the dual-mode ADC. Health condition is examined after the counted pulse rate is accumulated for 1 minute in the discriminator. If the pulse rate is out of the preset normal range, the dual-mode ADC operates in the ADC mode where pulse waveform is converted into 10-bit digital data with the sampling frequency of 1 kHz. These data are stored in a buffer and transmitted by 620 kbps to an external monitor through a RF transmitter. The data transmission period of the RF transmitter depends on the operation mode. It is generally 1 minute in the normal situation or 1 ms in the emergency situation. The proposed readout circuit was designed with $0.11{\mu}m$ process technology. The chip area is $460{\times}800{\mu}m^2$. According to measurement, the power consumption is $161.8{\mu}W$ in the count mode and $507.3{\mu}W$ in the ADC mode with the operating voltage of 1 V.