• Journal of the Korea Society of Computer and Information
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• v.14 no.8
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• pp.51-58
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• 2009

In this paper. we propose search algorithm using Low Peak Feature of audio and image color value by which similar movies can be identified. Combing through entire video files for the purpose of recognizing and retrieving matching movies requires much time and memory space. Moreover, these methods still share a critical problem of erroneously recognizing as being different matching videos that have been altered only in resolution or converted merely with a different codec. Thus we present here a similar-video-retrieval method that relies on analysis of audio patterns, whose peak features are not greatly affected by changes in the resolution or codec used and image color values. which are used for similarity comparison. The method showed a 97.7% search success rate, given a set of 2,000 video files whose audio-bit-rate had been altered or were purposefully written in a different codec.

• Journal of Wind Energy
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• v.13 no.2
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• pp.13-22
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• 2022

In this study, the resonant motion of a floating offshore wind system due to negative damping was mitigated by peak shaving algorithms of the NREL ROSCO controller, and the decreased gains of the blade pitch controller by the gain detuning method for the floating system was increased to the gains of onshore baseline controller to improve the power performance of the turbine. To check the performance of the controller, the dynamic responses between the existing gain-detuned pitch controller and the ROSCO controller with peak shaving control for an OC4 floating offshore wind system were compared. As a result of DLC1.1 at near-rated wind speed, when peak shaving was applied, the average generator power decreased by 1.9%, but it was confirmed that the standard deviation was reduced and stability was improved with fast pitch regulation. In addition, since peak shaving reduces the maximum thrust of the rotor, was confirmed that not only are the loads of the blades and tower reduced, but the surge motion of the floater is also reduced, and the tension of the mooring lines is reduced.

• Journal of Internet of Things and Convergence
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• v.10 no.4
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• pp.21-26
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• 2024

The transmission of video data stored on a video server to a large number of clients with finite buffer sizes requires a transmission plan that considers factors such as the number of rate changes, peak rate, and the amount of rate variability. Such transmission plans are referred to as smoothing algorithms, examples of which include CBA, MCBA, and MVBA. This study proposes an algorithm to reduce the utilization of the peak rate and evaluates the performance of the proposed algorithm. The evaluation factors include the number of rate changes, peak rate, rate variability, buffer utilization, average rate, and peak rate utilization. The evaluation results show that the proposed algorithm exhibits lower buffer utilization, average rate, and peak rate utilization compared to the MVBA algorithm.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.2
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• pp.182-192
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• 2015

In this paper, we introduce how to change the reaction rate as mol concentration when we scan enhanced MRI with GBCA(Gadolinium Based Contrast Agent), Also show the changing patterns depending on diverse MRI sequences which are made by different physical principle. For this study, we made MRI phantom ourselves. We mixed 500 mmol Gadoteridol with Saline in each 28 different containers from 500 to 0 mmol. After that, MR phantom was scanned by physically different MRI sequences which are T1 SE, T2 FLAIR, T1 FLAIR, 3D FLASH, T1 3D SPACE and 3D SPCIR in 1.5T bore. The results were as follows : *T1 Spin echo's Total SI(Signal Intensity) was 15608.7, Max peak was 1352.6 in 1 mmol. *T2 FLAIR's Total SI was 9106.4, Max peak was 0.4 1721.6 in 1 mmol. *T1 FLAIR's Total SI was 20972.5, Max peak was 1604.9 in 1 mmol. *3D FLASH's Total SI was 20924.0, Max peak was 1425.7 in 40 mmol. *3D SPACE 1mm's Total SI was 6399.0, Max peak was 528.3 in 3 mmol. *3D SPACE 5mm's Total SI was 6276.5, Max peak was 514.6 in 2 mmol. *3D SPCIR's Total SI was 1778.8, Max peak was 383.8 in 0.4 mmol. In most sequences, High signal intensity was shown in diluted lower concentration rather than high concentration, And also graph's max peak and pattern had difference value according to the each different sequence. Through this paper which have quantitative result of GBCA's reaction rate depending on sequence, We expect that practical enhanced MR protocol can be performed in clinical field.

• Tuberculosis and Respiratory Diseases
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• v.50 no.3
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• pp.310-319
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• 2001

Background : The peak flowmeter is very useful in monitoring of out-patients as well as those in emergency departments because of its convenience and simplicity with low cost. There have been many studies aimed at determining the accuracy and reproducibility of the peak flow meter in normal population. However, there is a paucity of reports regarding its accuracy in patients with chronic obstructive pulmonary disease(COPD) or asthma. The accuracy of the peak expiratory flow(PEF) measured with a mini-Wright peak flowmeter was assessed by a comparison with the results of a mass flow sensor. Methods : The PEF measurements were performed in 108 patients aged 19-82 years presenting with either a chronic obstructive lung disease or asthma before and after inhaling salbutamol. The PEF measurements from the mini-Wright flowmeter were compared with those obtained by the calibrated mass flow sensor. Results : The average of the readings taken by the mini-Wright meter were 37-39 l/min higher than those taken by the mass flow sensor. The average percentage error of the mini-Wright meter were higher, ranging less than 300 l/min. The mean of the differences between the values obtained using both instruments (the bias)$\pm$limits of agreement(${\pm}2$ SD) were $37.1{\pm}90\;l/min$ for the PEF(p<0.001). Conclusions : The mini-Wright peak flowmeter overestimated the flows in patients with COPD or asthma. It was also found that the accuracy of the mini-Wright peak flowmeter decreased in its mid to low range. The limits of agreement are wide and the difference between the two instruments is significant. Therefore, the measurements made between the two types of machines in patients with asthma or COPD cannot be used interchangeably.

• Journal of Korea Water Resources Association
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• v.56 no.11
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• pp.785-799
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• 2023

In this study, we proposed a new concept termed the Secondary Peak Constant (SPC) and discerned the temporal characteristics of independent rainstorm events based on unit time and SPC about 24 observation stations in Seoul. Utilizing rainfall observations from 2000 to 2022, independent rainstorm events discreted from rainfall data per unit time. The temporal characteristics of these events were derived according to unit time, and temporal characteristics of the peak rainfall were identified through the SPC. Finally, the temporal characteristics of independent rainstorm events were examined distinctively when analyzed by unit time and SPC. Independent rainstorm events with smaller unit time showed significantly larger total rainfall, rainfall duration, and rainfall intensity. The temporal characteristics of the largest peak rainfall (1^st Peak) within independent rainstorm events followed a sequence of Q4>Q2>Q3>Q1. Additionally, the 2^nd Peak rainfall predominantly occurred the location where the 1^st Peak appeared. The proportion of independent rainstorm events with multiple peak rainfalls exceeded 50.0% when the SPC was 0.7 or lower. The average number of peak rainfalls within independent rainstorm events ranged from 1.5 to 3.4. This study identified the temporal characteristics of independent rainstorm events based on unit time. Then, the peak rainfall of temporal characteristics was quantified by SPC on this study. Hence, it is evident that the temporal characteristics of independent rainstorm events for specific area can be anlayzed and quantified based on unit time and SPC.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.343-347
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• 1999

We fabricated a resistive SFCL having a shunt resistor parallel to it in order to bifurcate the transient current at faults. The SFCL consists of a YBCO film coated with an Au layer (10 ${\omega}$ at room temperature), which is to disperse the heat generated at hot spots in the YBCO film, and the 5 ${\omega}$ shunt resistor. The minimum quench current of the SFCL was found to be 12.2 A$_{peak}$. This SFCL successfully controlled the fault current below 23 A$_{peak}$ which is otherwise to increase up to 113 A$_{peak}$. Bifurcation of the current resulted in the temperature rise of the YBCO/Au film 3 times slower than without the shunt, protecting the SFCL at high currents.

• Journal of the Korean Society for Nondestructive Testing
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• v.35 no.5
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• pp.291-298
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• 2015

An array type probe for monitoring metal tubes is proposed in this paper which utilizes peak value and peak time of a pulsed eddy current(PEC) signal. The probe consists of an array of encircling coils along a tube and the outside of coils is shielded by ferrite to prevent source magnetic fields from directly affecting sensor signals since it is the magnetic fields produced by eddy currents that reflect the condition of metal tubes. The positions of both exciter and sensor coils are consecutively moved automatically so that manual scanning is not necessary. At one position of send-receive coils, peak value and peak time are extracted from a sensor PEC signal and these data are accumulated for all positions to form an array type peak value signal and an array type peak time signal. Numerical simulation was performed using the backward difference method in time and the finite element method for spatial analysis. Simulation results showed that peak value increases and the peak appears earlier as the defect depth or length increases. The proposed array signals are shown to be excellent in reflecting the defect location as well as variations of defect depth and length within the array probe.

• Journal of Navigation and Port Research
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• v.38 no.6
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• pp.695-700
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• 2014

This paper analyzed the peak stage of typhoons by using 10 years(2002~2011) data. The main purpose of this research is to provide the characteristic and tendency of peak stage of typhoons for navigators of ship. The research results show that typhoons of maximum wind speed 20~29m/ s and 40~49m/s account for 25% and 24% of whole typhoon, respectively. Ultra Typhoon of maximum wind speed 50m/ s and over accounts for 24% of whole typhoon. Peak stage mean arrival time from tropical depression and tropical storm are 3.6 days and 2.1 days, respectively. Duration time of peak stage is within 2 days and mean duration time of peak stage is 31hours. Latitudes and longitudes that mainly appears peak stage are at $15^{\circ}{\sim}25^{\circ}N$ and $120^{\circ}{\sim}140^{\circ}E$. This dangerous sea area has the oceanic environmental characteristic that Taiwan and Philippines are locate west side and a vast the North Pacific occupy east side. Navigators of ship in this dangerous sea area keep strict watch. Ultra Typhoons occur most frequently in September. Peak stage of Ultra Typhoon also appears at $15^{\circ}{\sim}25^{\circ}N$ and $120^{\circ}{\sim}140^{\circ}E$.

• Water for future
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• v.19 no.2
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• pp.157-166
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• 1986

The objective of this study was to determine the best representative synthetic unit hydrograph that is applicable to ungaged small watershed. A typical unit hydrograph was established with the actual data from a small watershed. Four currently well-known methods for analyzing ungaged small watershed, including Snyder's, Clark's S.C.S. and Nash methods, were evaluated with the data from the same small watershed. The following observations were noted from the analysis of four methods. The Snyder's method yielded the similar peak discharge value as the typical unit hydrograph. With co-ordinates of three discharge values, i.e. 25%, 50% and 75% of peak discharge, were not adequate for deriving a typical unit hydrograph in ungaged small watershed. With Clark's method there shall be some way of obtaining the exact base length of time area diagram and isochrone of each reach of the stream. With Nash method peak discharge and base flow time are affected by the storage constant and gamma function argument; therefore, for deriving a more reliable and workable unit hydrograph one needs to select for the better estimation of storage constant and gamma function argument. In S.C.S. method peak discharge is directly related to the watershed area and inversely related to the time of peak diacharge. Therefore area with faster peak discharge yielded the higer peak discharge value. Although the peak discharge value obtained frome the S.C.S. method higher than the value obtained from the unit hydrograph developed from the actual data, this method contains a number of advantageous factors. The peak discharge value and the time of peak discharge can be claculated easity from the morphological characteristics of the watershed, and in S.C.S method co-ordinates of the unit hydrograph can be calculated easily from that of the dimensionless unit hydrograph. When the four currently used methods were evaluated with a typical unit hydrograph obtained from the actual data, the S.C.S method was show to be the best method in deriving a synthetic unit hydrograph for ungaged small watershed.