• KSBB Journal
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• v.32 no.2
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• pp.117-123
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• 2017

Maple tree is a useful medical plant for obtaining bioactive materials such as pharmaceutics, cosmetics, food additive, etc., and there are 16 species of native maple trees in Korea. In this study, we evaluated the antioxidant activity of sap and crude extracts of Acer mono Max, a representative maple species. The crude extracts were obtained by solvent extraction (water, ethanol, and ethyl acetate) from its branches (bark and xylem). The phenolic contents and radical scavenging capacities of the extracts and the sap were evaluated in terms of half maximal effective concentration ($EC_{50}$) and kinetics by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The ethanol extracts showed the highest extraction yield, phenolic contents and antioxidant activity, and bark extracts showed better antioxidant activity than xylem extracts. The antioxidant activity of the sap was very low, but the $EC_{50}$ of ethanol and ethyl acetate extracts ranged from 68 to $79{\mu}g/mL$, similar to that ($60{\mu}g/mL$) of the control, butylated hydroxytoluene (BHT). The DPPH radical scavenging rate ($220{\sim}760{\mu}M/min$) and the second-order reaction rate constant ($6.48{\sim}7.04L/g{\cdot}min$) of these extracts were better than those of BHT ($55{\sim}370{\mu}M/min$ and $3.60L/g{\cdot}min$). These results suggest that A. mono Max. is one of the useful bioresources for obtaining antioxidant biologically active substances, and it is possible to obtain physiologically active substances from by-product of its pruning while minimizing the effect on the growth of the tree.

• The Korean Journal of Physiology
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• v.27 no.2
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• pp.209-215
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• 1993

The aim of the present study was to derive regression equations for $\dot{V}o_{2max}\;vs.\;\dot{V}o_{2peak},\;and\;\dot{V}o_2\;vs.$ heart rate, exercise time, and other variables from maximal exercise tests on a treadmill using the Bruce and inclined protocols. Twelve male and 10 female Korean college students aged between 19 and 23 years voIunteered for this study. After the resting measurements, the subjects performed a maximal exercise on a treadmill according to the Bruce protocol. When the resting conditions were restored, the subjects performed another maximal exercise according to an inclined protocol where the speed was fixed at 8.05 $km{\cdot}h^{-1}$ and the grade was incremented starting from 09t by 2.5% for every 2 min. Peak $\dot{V}o_2$ observed during the Bruce exercise $(\dot{V}o_{2peak})$ was $37.7{\pm}2.4\;and\;31.7{\pm}1.8\;ml\;kg^{-1}\;min^{-1}$ in the male and female groups, respectively. Peak $\dot{V}o_2$ observed during the inclined exercise was higher than $\dot{V}o_{2peak}$ during the Bruce exercise. Maximum $\dot{V}o_2$ value observed during the tyro exercises $(\dot{V}o_{2max})$ was $43.0{\pm}2.8\;and\;36.2{\pm}1.4\;ml\;kg^{-1}\;min^{-1}$ in the male and female groups, respectively. Thus, $\dot{V}o_{2peak}$ by the Bruce protocol was about 12% (male) or 13% (female) lower than $\dot{V}o_{2max}$, and a linear relationship was found between $\dot{V}o_{2peak}$ and $\dot{V}o_{2max}$. The peak values of % $\dot{V}o_{max}$ with the Bruce protocol were $89.2{\pm}3.3\;and\;87.5{\pm}3.6%$ and those with the inclined protocol $97.7{\pm}1.8\;and\;96.9{\pm}2.0%$ in the male and female groups, respectively. In the female group, $%\dot{V}o_{2max}$ at a given workload was higher than in the male group, while $\dot{V}o_{2}$ per kg body weight was the same. Maximum HR observed during the two exercises was $204{\pm}2\;and\;195{\pm}3\;beat\;min^{-1}$ in the male and female groups, respectively. Linear relationships were found, excluding the last points, between 1) $\dot{V}o_{2}$ and exercise time, 2) $\dot{V}o_{2}$ and $%\dot{V}o_{2max}\;and\;%HR_{max}$.

• Phonetics and Speech Sciences
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• v.14 no.4
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• pp.67-75
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• 2022

This study compared voice range profiles (VRPs) of modal and falsetto register in 53 dysphonic and 53 non-dysphonic adult women with gliding vowel /a/'. The results shows that maximum fundamental frequency (F0_MAX), maximum intensity (I_MAX), F0 range (F0_RANGE), and intensity range (I_RANGE) are lower in the dysphonic group than in the non-dysphonic group. F0_MAX and F0_RANGE are significantly higher in falsetto register than modal register in both groups. I_MAX and I_RANGE are significantly higher in falsetto register in the non-dysphonic group, but those are not different between two registers in the dysphonic group. There was no statistically significant difference in minimum F0 (F0_MIN) and minimum intensity (I_MIN) between the two groups. Modal-falsetto register transition occurred at 378.86 Hz (F4#) in the dysphonic group and 557.79 Hz (C5#) in the non-dysphonic group, which was significantly lower in the dysphonic group. It can be seen that both modal and falsetto registers in dysphonic adult women are reduced compared to non-dysphoinc adult women, indicating that the vocal folds of dysphonic adult women are not easy to vibrate in high pitches. The results of this study would be the basic data for understanding the acoustic features of voice disorders.

• Tuberculosis and Respiratory Diseases
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• v.46 no.2
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• pp.204-214
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• 1999

Background: Resting pulmonary function tests(PFTs) are routinely used in the evaluation of pulmonary impairment/disability. But the significance of the cardiopulmonary exercise test(CPX) in the evaluation of pulmonary impairment is controvertible. Many experts believe that dyspnea, though a necessary part of the assessment, is not a reliable predictor of impairment. Nevertheless, oxygen requirements of an organism at rest are different from at activity or exercising, and a clear relationship between resting PFTs and exercise tolerance has not been established in patients with chronic pulmonary disease. As well, the relationship between resting PFTs and dyspnea is complex. To investigate the relationship of dyspnea, resting PFTs, and CPX, we evaluated the patients of stabilized chronic pulmonary disease with clinical dyspnea rating(baseline dyspnea index, BDI), resting PFTs, and CPX. Method: The 50 patients were divided into two groups: non-severe and severe group on basis of results of resting PFTs(by criteria of ATS), CPX(by criteria of ATS or Ortega), and dyspnea rating(by focal score of BDI). Groups were compared with respect to pulmonary function, indices of CPX, and dyspnea rating. Results: 1. According to the criteria of pulmonary impairment with resting PFTs, $VO_2$max, and focal score of BDI were significantly low in the severe group(p<0.01). According to the criteria of $VO_2$max(ml/kg/min) and $VO_2$max(%), the parameters of resting PFTs, except $FEV_1$ were not significantly different between non-severe and severe(p>0.05). According to focal score($FEV_1$(%), FVC(%), MW(%), $FEV_1/FVC$, and $VO_2$max were significantly lower in the severe group(p<0.01). However, in the more severe dyspneic group(focal score<5), only $VO_2$max(ml/kg/min) and $VO_2$max(%) were low(p<0.01). $FEV_1$(%) was correlated with $VO_2$max(%)(r=0.52;p<0.01), but not predictive of exercise performance. The focal score had the correlation with max WR(%) (r=0.55;p<0.01). Sensitivity and specificity analysis were utilized to compare the different criteria used to evaluate the severity of pulmonary impairment, revealed that the classification would be different according to the criteria used. And focal score for dyspnea showed similar sensitivity and specificity. Conclusion : According to these result, resting PFTs were not superior to rating of dyspnea in prediction of exercise performance in patients with chronic pulmonary diseases and less correlative with focal score for dyspnea than $VO_2$max and max WR. Therefore, if not contraindicated, CPX would be considered to evaluate the severity of pulmonary impairment in patients with chronic pulmonary diseases, including with severe resting PFTs. Current criteria used to evaluate the severity of impairment were insufficient in considering the degree of dyspnea, so new criteria, including the severity of dyspnea, may be necessary.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.4
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• pp.375-383
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• 2012

Together with the GPS-based approach, geolocation through mobile communication networks is a key technology for location-based service. Since the Mobile WiMAX system is considered as a candidate for fourth-generation mobile systems, it is important to investigate its location capability. The geolocation of Mobile WiMAX can be realized when the preamble symbols in the down-link channel are appropriately used for a TDOA (Time-Difference-of-Arrival) approach. However, the cellular structure of Mobile WiMAX inevitably generates co-channel interference, and it is difficult for the mobile terminal to acquire distance measurements from multiple base stations. Therefore, for geolocation via multilateration using the Mobile WiMAX network, it is very important to increase hearability. This paper proposes a geolocation method for Mobile WiMAX which employs interference cancellation and preamble signal overlapping for the enhancement of hearability. A novel interference cancellation strategy for complex-valued Mobile WiMAX signals is presented which has an iterative structure. Simulation results show that the proposed geolocation method provides the user's position with an accuracy of less than 20 m through the Mobile WiMAX cellular network if there is no multi-path or NLOS (None-Line-of-Sight).

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.3
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• pp.347-352
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• 2010

There is a lack of survey standard for cross-to-nature small stream. In this research, we analyzed cross sectional survey data of Sanggachun stream, calculated variant quantity of soil, and suggested a survey interval. Descriptive analysis of cross sectional survey data shows the trend of stabilization; mean interval of survey is 14.91m(min: 7.0m, max: 39m), mean cross sectional variances are $0.82m^2$(min: $-3.80m^2$, max: $8.11m^2$) in 2004, $0.24m^2$ (min: $-5.25m^2$, max: $8.55m^2$) in 2005. Calculating results of variance quantity based on data of 65 cross sections show similar trends in 15m, 30m, 45m, 60m but different with results of 75m, 90m with Post-Hoc Test in statistical verification. We suggested standard cross sectional survey length of cross section for natural style small stream as 50m based on fitting results of standard variation of erosion and cumulation quantity by survey interval.

• Korean Journal of Environment and Ecology
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• v.29 no.6
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• pp.858-864
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• 2015

Developmental changes in the vocal signals of serotine bats (Eptesicus serotinus) during their infancy were examined in this study. The analysis was conducted on 4 infant serotine bats from 1 to 40 days after their birth. Pulse duration (PD), pulse interval (PI), peak frequency (PF), maximum frequency ($F_{MAX}$), minimum frequency ($F_{MIN}$), and bandwidth (BW) were measured. As the bats grew, their vocalizations became increasingly consistent and similar to those of adults. For infant bats, PD and PI decreased as they grew older, whereas PF, $F_{MAX}$, $F_{MIN}$, and BW increased. The greatest change in vocalizations was observed between the $10^{th}$ and $20^{th}$ days after birth. Also, PF, $F_{MAX}$, $F_{MIN}$ and BW, which describe sound frequency, increased dramatically during the period between the $10^{th}$ and the $20^{th}$ days. In contrast, the greatest change in PD occurred between the $30^{th}$ and $40^{th}$ days after birth. The results collected in this study suggest that frequency increased as the contraction ability of the muscles developed by around 20 days of age. Muscle relaxation ability, which is related to PD, was found to develop significantly at 30 to 40 days of age. According to the results of this study, although 40 day-old infant bats are not yet able to fly, their vocal signals were similar to those of adults. This indicates that vocal development and flying activity develop separately in young bats.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.2
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• pp.22-27
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• 2014

Purpose There is the recent PET/CT scan in tendency that use low dose to reduce patient's exposure along with development of equipments. We diminished $^{18}F$-FDG dose of patient to reduce patient's exposure after setting up GE Discovery 690 PET/CT scanner (GE Healthcare, Milwaukee, USA) establishment at this hospital in 2011. Accordingly, We evaluate acquisition time per proper bed by change of infusion dose to maintain quality of image of PET/CT scanner. Materials and Methods We inserted Air, Teflon, hot cylinder in NEMA NU2-1994 phantom and maintained radioactivity concentration based on the ratio 4:1 of hot cylinder and back ground activity and increased hot cylinder's concentration to 3, 4.3, 5.5, 6.7 MBq/kg, after acquisition image as increase acquisition time per bed to 30 seconds, 1 minute, 1 minute 30 seconds, 2 minute, 2 minutes 30 seconds, 3 minutes, 3 minutes 30 seconds, 4 minutes, 4 minutes 30 seconds, 5 minutes, 5 minutes 30 seconds, 10 minutes, 20 minutes, and 30 minutes, ROI was set up on hot cylinder and back radioactivity region. We computated standard deviation of Signal to Noise Ratio (SNR) and BKG (Background), compared with hot cylinder's concentration and change by acquisition time per bed, after measured Standard Uptake Value maximum ($SUV_{max}$). Also, we compared each standard deviation of $SUV_{max}$, SNR, BKG following in change of inspection waiting time (15minutes and 1 hour) by using 4.3 MBq phantom. Results The radioactive concentration per unit mass was increased to 3, 4.3, 5.5, 6.7 MBqs. And when we increased time/bed of each concentration from 1 minute 30 seconds to 30 minutes, we found that the $SUV_{max}$ of hot cylinder acquisition time per bed changed seriously according to each radioactive concentration in up to 18.3 to at least 7.3 from 30 seconds to 2 minutes. On the other side, that displayed changelessly at least 5.6 in up to 8 from 2 minutes 30 seconds to 30 minutes. SNR by radioactive change per unit mass was fixed to up to 0.49 in at least 0.41 in 3 MBqs and accroding as acquisition time per bed increased, rose to up to 0.59, 0.54 in each at least 0.23, 0.39 in 4.3 MBqs and in 5.5 MBqs. It was high to up to 0.59 from 30 seconds in radioactivity concentration 6.7 MBqs, but kept fixed from 0.43 to 0.53. Standard deviation of BKG (Background) was low from 0.38 to 0.06 in 3 MBqs and from 2 minutes 30 seconds after, low from 0.38 to 0 in 4.3 MBqs and 5.5 MBqs from 1 minute 30 seconds after, low from 0.33 to 0.05 in 6.7 MBqs at all section from 30 seconds to 30 minutes. In result that was changed the inspection waiting time to 15 minutes and 1 hour by 4.3 MBq phantoms, $SUV_{max}$ represented each other fixed values from 2 minutes 30 seconds of acquisition time per bed and SNR shown similar values from 1 minute 30 seconds. Conclusion As shown in the above, when we increased radioactive concentration per unit mass by 3, 4.3, 5.5, 6.7 MBqs, the values of $SUV_{max}$ and SNR was kept changelessly each other more than 2 minutes 30 seconds of acquisition time per bed. In the same way, in the change of inspection waiting time (15 minutes and 1 hour), we could find that the values of $SUV_{max}$ and SNR was kept changelessly each other more than 2 minutes 30 seconds of acquisition time per bed. In the result of this NEMA NU2-1994 phantom experiment, we found that the minimum acquisition time per bed was 2 minutes 30 seconds for evaluating values of fixed $SUV_{max}$ and SNR even in change of inserting radioactive concentration. However, this acquisition time can be different according to features and qualities of equipment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.229-232
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• 2012

This paper describes performance evaluation using fixed-point Matlab modeling and simulation, and hardware design of LDPC decoder which is based on Improved Normalized Min-Sum(INMS) decoding algorithm. The designed LDPC decoder supports 19 block lengths(576~2304) and 6 code rates(1/2, 2/3A, 2/3B, 3/4A, 3/4B, 5/6) of IEEE 802.16e mobile WiMAX standard. Considering hardware complexity, it is designed using a block-serial(partially parallel) architecture which is based on layered decoding scheme. A DFU based on sign-magnitude arithmetic is adopted to minimize hardware area. Hardware design is optimized by using INMS decoding algorithm whose performance is better than min-sum algorithm.

• Korean Journal of Exercise Nutrition
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• v.23 no.2
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• pp.45-50
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• 2019

[Purpose] The purpose of this study was to confirm that the difference in excess post-exercise oxygen consumption (EPOC) during exercise of the spending the same calories between the continuous and interval exercise. [Methods] Thirty-four healthy college students who did not regularly exercise volunteered to participate in our study. Continuous exercise was performed on an ergometer for 30 min at 60% of maximal oxygen consumption (VO_{2 max}). Interval exercise was performed on a cycle ergometer at 80% VO_{2 max} for 2 min initially, followed by 40% VO_{2 max} for 1 min, and 80% VO_{2 max} for 3 min. This was repeated six times for a total of 26 min. [Results] The major findings were as follows: (1) energy consumption during exercise was not significantly different between continuous exercise and interval exercise groups; (2) EPOC was higher in interval exercise than in continuous exercise for all dependent variables (i.e., total oxygen consumption, total calories, summation of heart rate); and (3) there were no significant differences in the lipid profile between continuous and interval groups. [Conclusions] Our study confirmed that after equalizing energy expenditure for continuous and interval exercise on a cycle ergometer in subjects in their twenties, interval exercise results in higher EPOC than continuous exercise. These data suggest that interval exercise may be more effective than continuous exercise in reducing body fat, for a given amount of energy expenditure.