• 한국식품과학회지
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• 제39권1호
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• pp.33-38
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• 2007

밀가루에 소금을 0, 2 및 4%를 첨가하였을 경우, Mixograph의 peak time은 밀가루의 종류에 관계없이 소금 첨가량이 증가함에 따라서 증가함을 알 수 있었으나 박력분의 경우에는 유의적인 차이를 나타내지는 않았다. Peak height와 width at peak도 소금 첨가량이 증가함에 따라 증가하는 경향을 나타내었으나 강력분과 중력분에서는 유의적인 차이를 나타내지 않았다. Width at 8 min의 경우에는 모든 밀가루에서 소금 첨가량이 증가함에 따라 증가하는 경향을 나타내었다. Sodium carbonate를 0, 0.5, 1.0 및 1.5의 농도로 밀가루에 첨가하여 Mixograph 특성을 관찰한 결과 밀가루의 종류에 관계없이 0.5% 첨가 시 peak time이 거의 2배정도 증가하였다가 그 보다 높은 농도에서는 다시 감소된 반면, peak height는 sodium carbonate 첨가량이 증가함에 따라서 감소하는 경향을 보였다. Mixograph peak time과 단백질 함량 및 침전가와는 유의적인 상관이 없었으나, peak height, width at peak 및 width at 8min과는 모두 정의 상관관계를 보여 주었다. 반죽의 초기호화온도, 최고점도, 최소점도, 최종점도는 밀가루의 종류에 관계없이 소금의 첨가량이 증가함에 따라 증가하는 경향을 나타내었으며, 최고점도, 최소점도 및 최종점도는 모든 밀가루에서 sodium carbonate 첨가량이 증가함에 따라서 유의적으로 증가하는 경향을 보였다. 초기호화온도와 보수율 및 알칼리수 흡수율과는 정의 상관이 있었으나, 보수율과 최고점도, 최소점도 및 최종점도와는 모두 부의 상관관계를 보여 주었다.

• 한국수자원학회논문집
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• 제43권7호
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• pp.635-643
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• 2010

작은 규모 유역의 홍수 유출량을 산출하기 위해서 유역을 대표하는 하나의 단위유량도를 많이 적용해 왔다. 이 때 단위유량도의 첨두유량과 첨두 발생시간은 단위유량도를 결정하는 특성치로 취급된다. 본 연구에서는 국내에서 $8.5\;km^2$ 정도의 소규모 유역에서도 강우 사상별로 단위유량도의 첨두유량과 발생시간은 상당히 변동되는 것을 보이고 분석하였다. 그리고 동일 소유역에서 단위유량도 변동의 주요인으로 강우 사상별 평균 강우강도라고 보고 강우 사상별 강우강도와 단위유량도의 첨두유량 및 발생시간의 관계를 각각 지수함수식으로 제시하였다. 결과적으로 사용 자료상의 제약 등으로 단위유량도 첨두치에상당한 분산을 동반하는 한계는있지만 연구된 대로 단위유량도의첨두유량 및 첨두 발생시간과 강우의 평균적인 회귀 관계는 단위유량도 이론의 보완적 측면에서 수문학적 가치를 갖는다.

• Fibers and Polymers
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• 제6권4호
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• pp.339-342
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• 2005

In this paper, a hand-operating method (tiled test method) of the wool-blending sample is made out, and make use of the method, the test of wool-blending bundle in different blending ratio is accomplished. According to the test data, the synthesis method of the stretch curve is worked out and the synthesis software for the typical stretch curve of wool-blending bundle is designed. Through laboratory hand-operating method, the blending fasciculus applying to fiber bundle test can be obtained in a short time. Calculation for sampling is accomplished in the article. We bring up 9 new signs to describe the characteristics of the curve behind peak for the first time: elongation behind peak (HE), elongation percentage behind peak (HEP), relative elongation rate behind peak (RHE), total break work $(W_a)$, break work behind peak (HW), break work coefficient behind peak (HWC), elongation percentage of half-load behind peak (HEL), load percentage of half-elongation behind peak (HLE), break efficiency behind peak (HEC).

• 한국농공학회지
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• 제37권3_4호
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• pp.34-47
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• 1995

It is experienced fact as a regular annual event that the structure to he designed on unreasonable flood for the agricultural structures including reservoirs have been brought not only loss of lives, but also enormous property damage. For the solution of this problem at issue, this study was conducted to develop an optimal runoff hydrograph model by comparison of the peak flows and time to peak between observed and simulated flows derived by linear time-invariant and linear time-variant models under the condition of having a short duration of heavy rainfall with uniform rainfall intensity at nine small watersheds which are within the range of 55.9 to 140.7 square kilometers in area in Han, Geum, Nagdong and Yeongsan Rivers. The results obtained through this study can be summarized as follows. 1. Storage constants and Gamma function arguments were calculated within the range of 1.2 to 6.42 and of 1.28 to 8.05 respectively by the moment method as the parameters for the analysis of runoff hydrograph based on linear time-invariant model. 2. Parameters for both linear time-invariant and linear time-variant models were calibrated with nine gaged watershed data, using a trial and error method. The resulting parameters including Gamma function argument, N and storage constant, K for linear time-invariant model were related statistically to watershed characteristic variables such as area, slope, length of main stream and the centroid length of the basin. 3. Average relative errors of the simulated peak discharge of calibrated runoff hydrographs by using linear time-variant and linear time-invariant models were shown to be 0.75 and 5.42 percent respectively to the peak of observed runoff hydrographs. Correlation coefficients for the statistical analysis in the same condition were shown to be 0.999 and 0.978 with a high significance respectively. Therefore, it can be concluded that the accuracy of a linear time-variant model is approaching more closely to the observed runoff hydrograph than that of a linear time-invariant model in the applied watersheds. 4. Average relative errors of the time to peak of calibrated runoff hydrographs by using linear time-variant and linear time-invariant models were shown to be 16.44 and 19.89 percent respectively to the time to peak of observed runoff hydrographs. Correlation coefficients in the same condition were also shown to be 0.999 and 0.886 with a high significance respectively. 5. It can be seen that the shape of simulated hydrograph based on a linear time- variant model is getting closer to the observed runoff hydrograph than that of a linear time-invariant model in the applied watersheds. 6. Two different models were verified with different rainfall-runoff events from data for the calibration by relative error and correlation analysis. Consequently, it can be generally concluded that verification results for the peak discharge and time to peak of simulated runoff hydrographs were in good agreement with those of calibrated runoff hydrographs.

• 대한인간공학회지
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• 제32권3호
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• pp.217-227
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• 2013

Objective: The purpose of this study was to analyze 'response time', 'peak response time' and 'overshoot value' for each muscle by applying the EMG signal to the vehicle response in ISO 7401 and to quantify the response of the driver according to vehicle characteristics by comparing vehicle characteristics and muscle responses of the driver. Background: The Open-loop test defined in international standards ISO 7401 is the only method for evaluating the performance of the vehicle. However, this test was focused only on mechanical responses, not driver's ones. Method: One skilled male driver(22 yrs. experience) was participated in this experiment to measure muscle activities of the driver in transient state. Then the seven muscle signals were applied to calculate 'response time', 'peak response time', and 'overshoot value'. Results: In the analyses of the EMG data, the effects of vehicle type and muscle were statistically significant on the 'response time' and 'peak response time'. Also, the effects of vehicle type, muscle, and lateral acceleration level were statistically significant on the 'overshoot value' in this study. According to the analyses of the vehicle motion data, vehicle motion variable(LatAcc, Roll, YawVel) was statistically significant on the 'response time' and vehicle type, vehicle motion variable, and lateral acceleration level were statistically significant on the 'peak response time', respectively. Conclusion: In the analyses of the 'response time' and 'overshoot value', the data of muscle activities(EMGs) was better index that could evaluate the vehicle characteristic and performance than the data of vehicle motion. In case of peak response time, both EMG and vehicle motion data were good index. Application: The EMGs data from a driver might be applicable as index for evaluation of various vehicle performances based on this study.

• Korean Journal of Hydrosciences
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• 제4권
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• pp.11-19
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• 1993

The peak flood discharge at a downstream station and the flood travel time between a pair of dams due to a specific flood release from the upper reservoir are computed using a hydraulic river channel routing method. The study covered the whole large reservoir system in the Han River, Korea. The computed flood discharges and the travel times between dams were correlated with the duration and the magnitude of flood release rate at the upstream reservoir, and hence a multiple regression model is proposed for each river reach between a pair of dams. The peak flood discharge at a downstream location can be converted to the peak flood stage by a rating curve. Hence, the proposed regression model could be used to forecast the peak flood stage at a downstream location and the flood travel time between dams using the information on the flood travel time, release rate and duration from the upper dam.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2010년도 한국우주과학회보 제19권1호
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• pp.38.2-38.2
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• 2010

We have examined the occurrence probability of solar proton events (SPEs) and their peak fluxes depending three flare parameters (X-ray peak flux, longitude, and impulsive time). For this we used NOAA SPEs from 1976 to 2006, and their associated X-ray flare data. As a result, we selected 166 proton events that were associated with major flares; 85 events associated with X-class flares and 81 events associated with M-class flares. Especially the occurrence probability strongly depends on these three parameters. In addition, the relationship between X-ray flare peak flux and proton peak flux as well as its correlation coefficient are strongly dependent on longitude and impulsive time. Among NOAA SPEs from 1997 to 2006, most of the events are related to both flares and CMEs but a few fraction of events (5/93) are only related with CMEs. We carefully identified the sources of these events using LASCO CME catalog and SOHO MDI data. Specifically, we examined the directions of CMEs related with the events and the history of active regions. As a result, we were able to determine active regions which are likely to produce SPEs without ambiguity as well as their longitudes at the time of SPEs by considering solar rotation rate. From this study, we found that the longitudes of five active regions are all between $90^{\circ}W$ and $120^{\circ}W$. When the flare peak time is assume to be the CME event time, we confirmed that the dependence of their rise times (proton peak time - flare peak time) on longitude are consistent with the previous empirical formula. These results imply that five events should be also associated with flares which were not observed because they occurred from back-side. Now we are examining the occurrence probability of SPEs depending on CME parameters. Finally, we will discuss the future prospects on the development of an empirical SPE forecast model based on the information of flares and CMEs.

• 한국운동역학회지
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• 제21권3호
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• pp.289-296
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• 2011

The purpose of this study was to quantify the biomechanical characteristics of the ground reaction force(GRF) during the Taekwondo's Apkubi, one of the basic movement in Taekwondo and the walking. The GRF profiles under the stance foot of Apkubi movement and walking were directly measured in sample of 20 healthy older persons. In the anterior-posterior and vertical direction, the GRF of the Apkubi movement reached to the peak braking force at 10% of the normalized stance time percent and the peak driving force at 90% of stance time, but that of the walking reached to the peak braking force at 20% of stance time and the peak driving force at 80% of stance time. In vertical force, the GRF of the walking showed two peak values, but that of the Apkubi movement seemed three peak values. Moreover the first peak vertical force was significantly(t=6.085, p<.001) greater in the walking(about 1.8 times of body weight) than the Apkubi(about 1.4 times of body weight). The walking velocity was affected significantly(over p<.05) by the braking impulse, the peak braking force and the first peak vertical force. Futhermore the peak braking force in the Apkubi showed a significant effect on the Apkubi's stride length(p<.01). So, we concluded that the braking force after the right touch down, the stance foot on the ground contributed to move the leg forward.

• International Journal of Concrete Structures and Materials
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• 제9권1호
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• pp.55-60
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• 2015

In this study, influence of different stone powders (SP), including limestone powders (LP), quartzite powders (QP), and granitic powders (GP), on the hydration behaviors of portland cement, for example, setting time, hydration heat, and hydration products, were discussed. The initial and the final setting time both shorten when the content of LP is 5 %, however, they are slightly delayed by the other two SPs. The LP has no obvious influence on the arrival time of the first peak in the exothermal curves, and it makes the peak value decrease; the other two SPs postpone the appearance of the first peak, and they also make the peak value decrease. For the second peak, LP shifts the peak position to the left, QP has no effect on this peak position, and GP makes the appearance of this peak delayed by 143 min. Similarly, three kinds of SPs have different influence on the hydration products of portland cement. The LP precipitates the formation of hydrated calcium carbo aluminate, the QP the formation of hydrated garnet, and the GP makes the amount of Tobermorite increase.

• 농촌지도와개발
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• 제13권2호
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• pp.287-298
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• 2006

The purpose of this study were to analyze the agricultural work and household work of farm couples. Time use survey are vital towards understanding social obligations and also an important input policy analysis. Rural farm work divided into the peak and the off-peak farming seasons was analysed to study the allocation of daily time use among farm couples. The major results are as follow: Farm work time is longer in the peak than in the off-peak. Especially, women farmer's farming work time in the off-peak is still longer than man farmer's that. The gender difference in total work time in this study shows that the women farmers work more. During both seasons, the time allocation of the women farmer were unbalanced because of the differences in the level of workload by gender.