• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.12 no.2
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• pp.21-25
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• 2006

Objective: The purposes of this study are to provide fundamental data and a rehabilitation program in physical therapy. It has been operated by 30 male college students for lumbar isokinetic exercises. Method : Subjects have been carried out in an experiment by Biodex system operating isokinetic torso rotation. This performance was activated by left rotation after right rotation repeatedly. Results: 1. The mean peak torques at $60^{\circ}$/sec were $95.6{\pm}20.62$ (Rt) and $93.84{\pm}18.41$ (Lt). 2. The mean peak torques/body weight at $60^{\circ}$/sec were $69.28{\pm}28.31$ (Rt) and $67.07{\pm}27.04$ (Lt). 3. The total works in right side at $60^{\circ}$/sec and $180^{\circ}$/sec were $492.21{\pm}92.37$, $1294.97{\pm}278.96$ and in left side at $60^{\circ}$/sec and $180^{\circ}$/sec were $515.78{\pm}109.47$, $1443.74{\pm}329.67$. 4. The work to body weight ratio at $60^{\circ}$/sec was $78.30{\pm}32.37$ (Rt) and $79.93{\pm}37.30$ (Lt). 5. The average powers in right side at $60^{\circ}$/sec and $180^{\circ}$/sec were $76.75{\pm}16.69$, $117.19{\pm}29.94$ and in left side at $60^{\circ}$/sec and $180^{\circ}$/sec were $78.54{\pm}18.58$, $125.39{\pm}32.90$. 6. The work fatigue at $180^{\circ}$/sec was $21.76{\pm}14.82$ (Rt) and $19.66{\pm}26.23$ (Lt). Conclusion: In right side and left side, there was no significant difference in peak torque. peak torque/body weight, work to body-weight ratio, average power of trunk rotators at $60^{\circ}$/sec(p<0.05). However there was a significant difference in the total work of trunk rotators at $60^{\circ}$/sec(p>0.05). Also there was a significant difference in the average of trunk rotators at $180^{\circ}$/sec(p>0.05).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.9C
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• pp.581-588
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• 2011

In this paper, we propose a novel unambiguous code tracking scheme for cosine phased binary offset carrier (BOC) signals. We first obtain the sub-correlation functions composing the BOC autocorrelation function, and then, re-combine the sub-correlation functions generating a correlation function with no side-peak. Finally, by using the correlation function with no side-peak in the delay lock loop, the proposed scheme performs unambiguous signal tracking. Numerical results demonstrate that the proposed scheme provides a performance improvement over the conventional unambiguous scheme in terms of the tracking error standard deviation (TESD).

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.8
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• pp.2879-2899
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• 2021

The tone reservation (TR) scheme is an attractive method to reduce peak-to-average power ratio (PAPR) in the filter bank multicarrier with offset quadrature amplitude modulation (FBMC-OQAM) systems. However, the high PAPR of FBMC signal will severely degrades system performance. To address this issue, a cyclic shift based TR (CS-TR) scheme with embedding side information (SI) is proposed to reduce the PAPR of FBMC signals. At the transmitter, four candidate signals are first generated based on cyclic shift of the output of inverse discrete Fourier transform (IDFT), and the SI of the selected signal with minimum peak power among the four candidate signals is embedded in sparse symbols with quadrature phase-shift keying constellation. Then, the TR weighted by optimal scaling factor is employed to further reduce PAPR of the selected signal. At the receiver, a reliable SI detector is presented by determining the phase rotation of SI embedding symbols, and the transmitted data blocks can be correctly demodulated according to the detected SI. Simulation results show that the proposed scheme significantly outperforms the existing TR schemes in both PAPR reduction and bit error rate (BER) performances. In addition, the proposed scheme with detected SI can achieve the same BER performance compared to the one with perfect SI.

• Journal of Communications and Networks
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• v.11 no.6
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• pp.556-563
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• 2009

A side channel analysis is a very efficient attack against small devices such as smart cards and wireless sensor nodes. In this paper, we propose an efficient key detection method using a peak selection algorithm in order to find the advanced encryption standard secret key from electromagnetic signals. The proposed method is applied to a correlation electromagnetic analysis (CEMA) attack against a wireless sensor node. Our approach results in increase in the correlation coefficient in comparison with the general CEMA. The experimental results show that the proposed method can efficiently and reliably uncover the entire 128-bit key with a small number of traces, whereas some extant methods can reveal only partial subkeys by using a large number of traces in the same conditions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.1
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• pp.322-340
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• 2012

Orthogonal Frequency Division Multiplexing (OFDM) is usually regarded as a spectral efficient multicarrier modulation technique, yet it suffers from a high peak-to-average power ratio (PAPR) problem. Among all the existing PAPR reduction techniques in OFDM systems, side information based PAPR reduction techniques such as partial transmit sequence (PTS) and selective mapping (SLM) schemes, have attracted the most attention. However, the transmission of side information results in somewhat spectral loss and this does not significantly improve the bit error rate (BER) performance. Parallel combinatory (PC) OFDM yields higher spectral efficiency (SE) and better BER performance on Gaussian channels,while is a little but not obvious PAPR improvement over the ordinary OFDM system. This investigation aimed to design a 'perfect' OFDM system. We introduce the side information to rotate the subcarrier phases of our novel PC-OFDM system structure, and call this new system the SIPC(Side information based Parallel Combinatory)-OFDM system. The proposed system achieves better PAPR and SE performance. In addition, considering the tradeoff of system parameters, the proposed system also has the properties of a higher BER.

• Journal of Korean Association for Spatial Structures
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• v.11 no.2
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• pp.63-70
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• 2011

Livestock buildings are rural facilities as vulnerable to natural disasters as vinyl houses. Many of livestock buildings have a roof but without side walls. The roof of such structures is easily blown away by a typhoon and this results in a heavy loss. Therefore, farmers install winch curtains on the sides to prevent damages caused by typhoons. This study purposed to examine the distribution of wind pressure coefficient among different positions of livestock shed roof according to the opening of side walls. It was found that according to the distribution of peak external pressure coefficient on the roof surface of livestock shed, the wind blowing at wind angle $0^{\circ}$ was disadvantageous to roof surface regardless of the presence of side walls. However, it was confirmed that the peak external pressure coefficient was affected by wind angle and the length of eave depending on the presence of side walls.

• Wind and Structures
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• v.28 no.5
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• pp.299-313
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• 2019

In order to examine the effects of different wind deflectors on the wind load distribution characteristics of extra-large cooling towers, a comparative study of the distribution characteristics of wind pressures on the surface of three large cooling towers with typical wind deflectors and one tower without wind deflector was conducted using wind tunnel tests. These characteristics include aerodynamic parameters such as mean wind pressures, fluctuating wind pressures, peak factors, correlation coefficients, extreme wind pressures, drag coefficients and vorticity distribution. Then distribution regularities of different wind deflectors on global and local wind pressure of extra-large cooling towers was extracted, and finally the fitting formula of extreme wind pressure of the cooling towers with different wind deflectors was provided. The results showed that the large eddy simulation (LES) method used in this article could be used to accurately simulate wind loads of such extra-large cooling towers. The three typical wind deflectors could effectively reduce the average wind pressure of the negative pressure extreme regions in the central part of the tower, and were also effective in reducing the root of the variance of the fluctuating wind pressure in the upper-middle part of the windward side of the tower, with the curved air deflector showing particularly. All the different wind deflectors effectively reduced the wind pressure extremes of the middle and lower regions of the windward side of the tower and of the negative pressure extremes region, with the best effect occurring in the curved wind deflector. After the wind deflectors were installed the drag coefficient values of each layer of the middle and lower parts of the tower were significantly higher than that without wind deflector, but the effect on the drag coefficients of layers above the throat was weak. The peak factors for the windward side, the side and leeward side of the extra-large cooling towers with different wind deflectors were set as 3.29, 3.41 and 3.50, respectively.

• Physical Therapy Korea
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• v.16 no.4
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• pp.31-36
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• 2009

Hemiplegia-induced immobilizatoin and reduction of mechanical loading in chronic stroke limbs are common cause of disuse osteoporosis. The purpose of this study was to investigate the effects of asymmetrical weight bearing on the loss of bone mineral in the individual with chronic stroke. Sixteen hemiplegic patients with strokes were evaluated. The measurements of bone mineral density (BMD) were evaluated with the quantitative ultrasound system on the calcaneus region of the paretic and non-paretic side. Plantar pressure was measured using the Mat-Scan system. The paretic side showed significantly smaller values in the T-score of BMD, and peak value of plantar pressure, which included forefoot, midfoot, and hindfoot, than the non-paretic side (p<.05). Results from the pearson correlation analysis showed statistically significant correlation between the BMD difference and the peak-pressure difference of midfoot pressure (p<.05). This finding indicated that BMD loss depended on decrease of body weight born on the paretic leg.

• ETRI Journal
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• v.37 no.1
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• pp.197-202
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• 2015

A smart grid is a modernized electrical grid that uses information about the behaviors of suppliers and consumers in an automated fashion to improve the efficiency, reliability, economics, and sustainability of the production and distribution of electricity. In the operation of a smart grid, demand side management (DSM) plays an important role in allowing customers to make informed decisions regarding their energy consumption. In addition, it helps energy providers reduce peak load demand and reshapes the load profile. In this paper, we propose a new DSM scheduling scheme that makes use of the day-ahead pricing strategy. Based on the Rubinstein-Stahl bargaining model, our pricing strategy allows consumers to make informed decisions regarding their power consumption, while reducing the peak-to-average ratio. With a simulation study, it is demonstrated that the proposed scheme can increase the sustainability of a smart grid and reduce overall operational costs.

• Proceedings of the KSPS conference
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• 2002.11a
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• pp.64-69
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• 2002

This study concerns the constraints of English Poetic Meter. In English poems, the metrical pattern doesn't always match the linguistic stress on the lines. These mismatches are found differently among the poets. For the lexical stress mismatched with the weak metrical position, $*W{\Rightarrow}{\;}Strength$ is established by the concept of the strong syllable. The peaks of monosyllabic words mismatched with the weak metrical position are divided according to which side of the boundary of a phonological domain they are adjacent to. Adjacency Constraint I is suggested for the mismatched peak which is adjacent to the left boundary of a phonological domain; *Peak] and Adjacency ConstraintII for the mismatched peak which are adjacent to the right boundary of a phonological domain. These constraints are various according to the poets(Pope, Milton and Shakespeare) : *[Peak [-stress], $W{\Rightarrow}{\;}*Strength$ and *Peak] in Pope; *[+stress][Peak [-stress] and *Peak] in Milton ; *[+stress][Peak [-stress], $W{\;}{\Rightarrow}{\;}*Strength$ and ACII in Shakespeare.