• Korean Journal of Ecology and Environment
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• v.41 no.1
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• pp.43-53
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• 2008

This study was conducted to simulate storm hydrographs on a small forested watershed using TOPMODEL, which is a distributed hydrological model. The Myeongseong watershed, which is 58.3 ha in size, was selected to monitor rainfall and runoff data. The Monte Carlo simulation was also used to calibrate parameters of TOPMODEL. Six rainfall-runoff pairs collected at the watershed in the year 1997 were used for parameter calibration, and eight rainfall-runoff pairs collected during the period of $1998\sim1999$ were used for validation effort. The errors of runoff volume ranged from -2.74% to 1.81%, and an average value of model efficiency in terms of runoff volume was 0.92 for the calibration period. The average value of observed peak discharge was $0.324m^3\;s^{-1}$ for six rainfall-runoff pairs, while the prediction value was $0.295m^3\;s^{-1}$. The simulation errors of peak discharge varied according to rainfall characteristics and antecedent condition, within ranges of -27.65% to -1.13%. The model efficiency for the validation period was 0.92. For the validation period, observed peak discharges have an average value of $0.087m^3\;s^{-1}$ and average value of simulated peak discharge was $0.090m^3\;s^{-1}$. Observed and simulated values of time to peak for the calibration period were 18.3 hrs and 11.0 hrs, respectively, and 16.6 hrs and 13.5 hrs, respectively, for the validation period.

• Journal of Nutrition and Health
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• v.34 no.5
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• pp.532-540
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• 2001

This study explored the effect of calcium levels and/or ovariectomy on bone composition and its related factors using the female Sprague-Dawley rats which achieved peak bone mass in normal(0.5%) calcium intake during growth period. The rats were randomly divided into six groups and fed 0.1%, 0.5% and 1.5% calcium diets for 8 weeks after ovariectomized and sham operation. The results indicated that body weight gain was higher in ovariectomized groups than sham groups, regardless of dietary calcium levels and food intakes. Serum Ca and P concentrations were normal level regardless of dietary calcium levels and operation. Estrogen concentration was decreased in ovariectomized rat groups. Serum alkaline phosphatase activity and urinary hydroxyproline were increased in ovariectomized groups. When rats were fed normal Ca diet during growing period, weight, length and breaking force of femur were not significantly different in all groups but increased the same level. Generally, lipid contents in lumbar and femur were lower in low calcium groups and this effect was more pronounced in femur. In case of femur, the significant decrease in Ca contents of bone was observed in a relatively short period of feeding low Ca diet, even though it appeared th desirable peak bone mass had achieved through the growing period by supplementing the adequate amount of calcium. The marked decrease of estrogen levels after ovariectomy did not seem to influence greatly bone parameters measured except bone wet weight. Therefore, this study indicated that lower intake of Ca might be more important determinating factor against osteoporosis than postmenopausal state stimulated by ovariectomy in female rats. With normal or high intake of Ca it appears possible to prevent bone loss in postmenopausal period, and this might apply only in case of achieving peak bone mass in the growing with the adequate intake of calcium. (Korean J Nutrition 34(5) : 532∼540, 2001)

• Journal of agricultural medicine and community health
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• v.47 no.2
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• pp.61-66
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• 2022

Objectives: In the epidemiology of communicable diseases, the term epidemic period, also referred to as "wave" is often used in the general and academic milieu. A wave refers to a natural pattern of increase in the number of sick individuals, a defined peak, and then a decline in the number of cases. It implies a pattern of peaks and valleys after a particular peak is taken. The idea of epidemic waves is a useful tool for predicting the course as well as helping to accurately describe an epidemic. However, in many domestic and foreign news as well as in various research results in Korea, most of the reports either had no standard, were inaccurate, had a questionable classification of the period of the epidemic, or the basis for classification of a given wave was not presented. Methods: The author reviewed and organized related literature with epidemic wave. The author made several suggestions of an epidemic wave as follows. Results: To start with, it should be based on the number of incident cases in consideration of the size of the outbreak, then the period from the bottom to the peak and then reaching the next bottom; also, the period over a certain scale based on the number of incident cases; and the period according to the change in the major infection type (mutation-dominant species). In addition, according to the period of change in the vaccination rate (formation of herd immunity), as well as the content and duration of the intervention, that is, classification according to the applied quarantine stage. Furthermore, the classification of epidemic periods by the time-dependent reproduction number or time-varying reproduction number (Rt), and lastly the application of mathematical methodology. Conclusions: Therefore, classifying the epidemic period into generally known and accepted time frames is considered to be a very important task for future research analysis and development of intervention strategies.

• Earthquakes and Structures
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• v.23 no.2
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• pp.115-128
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• 2022

One common method to select input ground motions to predict dynamic behavior of structures subjected to seismic excitation requires spectral acceleration (S_a) match target mean response spectrum. However, dispersion of ground motions, which explicitly affects the structural response, is rarely discussed in this method. Generally, selecting ground motions matching target mean and variance has been utilized as an appropriate method to predict reliable seismic response. The goal of this paper is to investigate the impact of target spectra variance of ground motions on structural seismic response. Two sets of ground motions with different target variances (zero variance and minimum variance larger than inherent variance of the target spectrum) are selected as input to two different structures. Structural responses at different heights are compared, in terms of peak, mean and dispersion. Results show that increase of target spectra variance tends to increase peak floor acceleration, peak deformation and dispersions of response of interest remarkably. To short-period structures, dispersion increase ratios of seismic response are close to that of S_a of input ground motions at the first period. To long-period structures, dispersions of floor acceleration and floor response spectra increase more significantly at the bottom, while dispersion increase ratios of IDR and deformation are close to that of S_a of input ground motions at the first period. This study could further provide useful information on selecting appropriate ground motion to predict seismic behavior of different types of structures.

• Journal of the Korean Institute of Telematics and Electronics
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• v.17 no.4
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• pp.38-44
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• 1980

We present a high speed pitch estimation algorithm that is based on peak detection and average magnitude difference function (AMDF). A few pitch candidates are first estimated from the low-pass filtered (800 Hz) speech by a peak detection algorithm. AMDF values of the pitch candidatestare then calculated, and the pitch candidate that yields the minimum AMDF value is chosen as the desired pitch period. The new method requires far less computation time than other pitch estimation algorithms, while it yields fairly accurate results.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.5
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• pp.47-52
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• 2011

We studied about the damaged tire decision algorithm that measured dominant period of ultrasonic signal due to a foreign material on the friction between tire and road surface. We computed the power spectrum about the envelope of ultrasonic signal acquired from the damaged tire, then proposed the dominant period decision algorithm by statistical power threshold value. As the result of simulation, when driving by the speed of 80km/h, the 100ms of dominant period that measured in the proposed algorithm is more accurate than the 97.6ms of power spectrum peak period referenced on the average period of ultrasonic signal envelope peak, 101.24ms.

• Earthquakes and Structures
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• v.18 no.2
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• pp.163-170
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• 2020

Floor acceleration plays a major role in the seismic design of nonstructural components and equipment supported by structures. Large floor acceleration may cause structural damage to or even collapse of buildings. For precision instruments in high-tech factories, even small floor accelerations can cause considerable damage in this study. Six P-wave parameters, namely the peak measurement of acceleration, peak measurement of velocity, peak measurement of displacement, effective predominant period, integral of squared velocity, and cumulative absolute velocity, were estimated from the first 3 s of a vertical ground acceleration time history. Subsequently, a new predictive algorithm was developed, which utilizes the aforementioned parameters with the floor height and fundamental period of the structure as the new inputs of a support vector regression model. Representative earthquakes, which were recorded by the Structure Strong Earthquake Monitoring System of the Central Weather Bureau in Taiwan from 1992 to 2016, were used to construct the support vector regression model for predicting the peak floor acceleration (PFA) of each floor. The results indicated that the accuracy of the predicted PFA, which was defined as a PFA within a one-level difference from the measured PFA on Taiwan's seismic intensity scale, was 96.96%. The proposed system can be integrated into the existing earthquake early warning system to provide complete protection to life and the economy.

• Journal of Pharmacopuncture
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• v.10 no.2 s.23
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• pp.119-132
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• 2007

This study was performed to determine whether a pulse analyzer was useful 1) to characterize the variables of pulse wave of cerebral infarction patieno (CI), compared with those of healthy subjects, as well as 2) to determine Sasang Constitution in CI and healthy subjects. 1. Calibrated in Gwan, the amount of energy(Energy), height of main peak(H1), height of aorticvalley(H2), height of aortic peak(H3), total area of pulse wave(At), and area of main peak width(Aw) of the CI group were higher than those of the healthy group. 2. Calibrated in Cheek, Energy, H1, H2, H3, height of valve valley(H4), At, Aw, and main peak angle(MPA) of the CI group were higher than those of the healthy group. 3. Among the healthy (subjects) group, Taeumin showed the highest contact pressure(CP) and height of valve peak(H5) calibrated in Chon. The main peak width divided by whole time of pulse wave(MPW/T) calibrated in Gwan and Cheok, was highest in Soyangin and was lowest in Taeumin. The H3 divided by H1(H3/H1) and the time to valve valley minus the time to main peak and divided by T[(T4-T1)/T] calibrated in Cheek were highest in Soyangin. The time to main peak(T1) was longest in Soumin. 4. Among the CI group, At calibrated in Chon was widest in Taeumin and was narrowest in Soumin The time to aortic peak(T3) calibrated in Cheek was longest in Soumin and was shortest in Soyangin. The time to valve peak(T5) was shortest in Soyangin. 5. There were main effects of cerebral infarction in the area of systolic period(As) and area of diastolic period(Ad) calibrated in Chon, Energy calibrated in Cwan, and Energy, H1, H2, H3, (H4+H5)/Hl, and MPA calibrated in Cheek. 6. There were main effects of Sasang Constitution in (T4-T1)/T, area of systolic period(As), and Ad calibrated in Chon. 7. The interactions between the cerebral infarction and Sasang Constitution were observed in H5/H1 , T, At, As, Ad, and MPA calibrated in Chon, H4, T4, (T4-T1)/T, As, and Ad calibrated in Cwan, and 74,75, and MPW calibrated in Cheok. Therefore, we concluded that pulse analyzer was useful to determine the risk degree of cerebral infarction and Sasang Constitution.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.4
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• pp.339-346
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• 2016

The aim of this research was to the experimental data using statistical and spectral analyzing method to get the motion reponses of a stern trawler in operation states such as drifting, sailing and trawling according to the wave height. In drifting, the significant and the maximum valuer of roll in beam sea increased according to the wave height, but those of pitch decreased. The response and the period of peak of roll in beam sea were increased, but those of pitch decreased. In navigation, the significant and maximum values of roll increased remarkably according to the wave height, but those of pitch changed a little. The response of roll was highest in quartering sea, beam sea and then following sea, but those of pitch was highest in bow sea, head sea and then beam sea in the order of all wave heights. The period of peak of roll due to the wave height and the wave direction changed from 3.8 to 9.9 seconds, and those of pitch changed from 3.3 to 10.4 seconds. In trawling, the significant and maximum values of roll increased a little according to the wave height, but those of pitch increased significantly. The response of roll was highest in beam sea, bow sea and then quartering sea, but those of pitch was highest in head sea, following sea, and then beam sea in the order. The period of peak of roll due to the wave height and the direction changed from 6.6 to 10.9 seconds, and those of pitch changed from 6.7 to 11.2 seconds.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.4005-4011
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• 2010

This study investigates the effect on automobile traffic flow of the bike lane configuration via the road diet implemented in Nam-Gu, Busan using the microscopic simulator TransModeler. The results show that the increases in average delay time and stopped time experienced by automobile vehicles after implementing the road diet during the peak period are significant, but those during the non-peak period are insignificant at alpha=0.1. The results in peak period are consistent with the results of the past studies, which concluded that a road diet can contribute to deteriorating the level of service when the automobile traffic flow rate on the existing roadway is relatively high. For the non-peak period, the analysis results may reflect the fact that the automobile traffic flow is not severly affected by the road diet due to the reserved capacity.