• Korean Journal of Construction Engineering and Management
• /
• v.3 no.3 s.11
• /
• pp.84-93
• /
• 2002

It is important to reduce construction duration in private sales and lease business for management of cash now in the owner's aspect. However, because the concept of standard duration hasn't been established in the domestic construction industry, it is difficult to present the standard of duration estimate. To solve this problem, this paper (1) grasped the effecting elements considered in the duration estimate through referring the existing literature related to the schedule management, (2) accomplished a comprehensive research on actual duration based on office buildings through the questionnaire survey and the expert interview, (3) presented the collected research data analyzed by effecting elements as standard duration, (4) compared standard duration with actual duration of countries advanced in construction projects as well as analyzed them, and then (5) raised the necessity of duration reduction in the domestic construction industry.

• MALSORI
• /
• no.27_28
• /
• pp.89-109
• /
• 1994

This thesis compares the duration aspect of the Daegu tongue with that of standard Korean. In the former study on the rhythm of standard Korean, one of the purposes of the study was to compare it with dialects. This thesis is the first attempt to do that. For this purpose, this thesis proceeds as follows. After Introduction, Chapter 2 surveys the former study. Chapter 3 deals with the materials, method and results of the experiment. Chapter 4 analyzes and interprets the results of the experiment, In Conclusion, the most Prominent fact is that the results of the experiment fall short of Daegu tongue speakers' expectations. The Daegu tongue is generally considered as a 'tone language.' And as Daegu tongue speakers sensitively recognize pitch, they think that they quickly say the syllables between the Pitch stressed syllables, whereas standard Korean speakers say those syllables relatively slowly, But in this experiment, which deals with only duration ignoring Pitch, their assumption is proved to be false.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• autumn
• /
• pp.531-534
• /
• 2001

At the beginning of construction, the estimation for the construction duration is very important to effectively control and use labors, builder's equipment, permanent and temporary materials, supplies and utilities, and money. In spite of the importance of the estimation for the construction duration, there is no estimation standard of optimal construction duration in korea. The purpose of this study is to suggest the estimation standard of optimal construction duration that is reasonable and systematical through developing the method for estimating, the construction duration. it is expected to be helpful for estimating, planning and scheduling. The analysis is executed the existing estimation standards and consulting the results of the interviews with the on-site engineers and the concrete compressive stress tests.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.65 no.4
• /
• pp.25-32
• /
• 2023

KDS (Korean Design Standard) for agricultural drainage is a planning standard that helps determine the appropriate capacity and type of drainage facilities. The objective of this study was to analyze the inundation of the agricultural basin considering the current design standard and the critical rainfall duration. This study used the rainfall durations of 1-48 hour, and the time distribution method with the Chicago and the modified Huff model. For the runoff model, the NRCS (Natural Resources Conservation Service) unit hydrograph method was applied, and the inundation depth and duration were analyzed using area-elevation data. From the inundation analysis using the modified Huff method with different rainfall durations, 4 hours showed the largest peak discharge, and 11 hours showed the largest inundation depth. From the comparison analysis with the current method (Chicago method with a duration of 48 hours) and the modified Huff method applying critical rainfall duration, the current method showed less peak discharge and lower inundation depth compared to the modified Huff method. From the simulation of changing values of drainage rate, the duration of 11 hours showed larger inundation depth and duration compared to the duration of 4 hours. Accordingly, the modified Huff method with the critical rainfall duration would likely be a safer design than the current method. Also, a process of choosing a design hydrograph considering the inundation depth and duration is needed to apply the critical rainfall duration. This study is expected to be helpful for the theoretical basis of the agricultural drainage design standards.

• Proceedings of the KSPS conference
• /
• 1996.02a
• /
• pp.179-182
• /
• 1996

This thesis compares the duration aspect of Daegu tongue with that of standard Korean. In the former study on the rhythm of standard Korean, one of the purposes of the study was to compare it with dialects. This thesis is the first attempt In do that. For this purpose, this thesis proceeds as follows. After Introduction, Chapter 2 surveys the former study, Chapter 3 deals with the materials, method and results of the experiment. Chapter 4 analyzes and interprets the results of the experiment. In Conclusion, the most prominent fact is that the results of the experiment fall short of Daegu tongue speakers' expectations. Daegu tongue is generally considered as ' tone language. ' And as Daegu tongue speakers sensitively recognize pitch, they think that they quitckly say the syllables between the pitch stressed syllables, whereas standard Korean speakers say those syllables relatively slowly. But in this experiment, which deals with only duration ignoring pitch, their assumption is proved to be false.

• Proceedings of the KSPS conference
• /
• 1996.10a
• /
• pp.379-383
• /
• 1996

This paper compares the duration aspect of Daegu tongue with that of standard Korean. In the former study on the rhythm of standard Korean, one of the purposes of the study was to compare it with dialects. This paper is the first attempt to do that. For this purpose, this paper proceeds as follows. After Introduction, Chapter 2 surveys the former study. Chapter 3 deals with the materials, method and results of the experiment. Chapter 4 analyzes and interprets the results of the experiment. In Conclusion, the most prominent fact is that the results of the experiment fall short of Daegu tongue speakers' expectations. Daegu tongue is generally considered as "tone language." And as Daegu tongue speakers sensitively recognize pitch, they think that they quitckly say the syllables between the pitch stressed syllables, whereas standard Korean speakers say those syllables relatively slowly. But in this experiment, which deals with only duration ignoring pitch, their assumption is proved to be false.

• Journal of Korean Society of Water and Wastewater
• /
• v.36 no.4
• /
• pp.229-237
• /
• 2022

The sewer capacity design have been based on the Huff model or the rational equation in South Korea and often failed to determine optimal capacity, resulting in frequent urban flooding or over-sizing. A time distribution of rainfall (i.e., Huff or ABM method) could be used instead of a rainfall hyetograph obtained from statistical analysis of previous rainfalls. In this study, the Huff method and the ABM method, which predict the time distribution of rain intensity, which are widely used to calculate sewage pipe drainage capacity using the SWMM, were compared with the standard rainfall intensity hyetograph of Seoul. If the rainfall duration was 30 minutes to 180 minutes, the rainfall intensity value calculated by the Huff model tended to be less than the rainfall intensity value of the standard rainfall intensity in the initial 5-10 minutes. As a result, more than 10% to 30% of under-design would be made. In addition, the rainfall intensity value calculated by the Huff model from the section excluding the initial 5-10 minutes of rainfall to the rainfall duration was calculated larger than the value using the standard rainfall intensity equation, which would result in an over-design of 10% to 30%. In the case of a relatively long rainfall duration of 360 minutes (6 hours) to 1,440 minutes (24 hours), it showed an lower rainfall intensity of 60 to 90% in the early stages of rainfall, but the problem of under-design had been solved as the rainfall duration time had elapsed. On the other hand, in the alternating block method (ABM) method, it was found that the rainfall intensity at the entire period at each assumed rainfall duration accurately matched the standard rainfall intensity hyetograph of Seoul.

• Journal of Korean Society on Water Environment
• /
• v.21 no.5
• /
• pp.516-519
• /
• 2005

An useful protocol coiled load duration curve methodology to estimate contaminant loading to a river on an exceedance probability scale was developed in this research. The technique was further applied to estimate total coliform loading to the Geum River, using the daily mean flow rate and total coliform concentration data during January, 1996 and July, 2004 for the Gongju where an automated monitoring station is located. Drought flow of the Gongju (=50.3 cms) was equivalent to 40% on an exceedance probability scale. Load duration curve for total coliform loading at the Gongju was constructed. Standard duration curve was constructed with the water quality criteria for the class 2 (total coliform concentration = 1000 MPN/100 mL). By plotting load duration curve with standard duration curve, it could be revealed that water quality do not meet the desired water quality for 47% on an exceedance probability scale. If linearity between flow rate and coliform concentration is assumed, it can be interpretated that water quality exceeds desired criteria when average mean flow rate is over 51 cms.

• Journal of Korean Society on Water Environment
• /
• v.29 no.4
• /
• pp.523-530
• /
• 2013

This study has been carried out to clarify the characteristics of discharge and pollutant loading according to flow conditions at jiseok stream watershed (JSW). A flow rate and pollutant load in the study watershed were estimated by equation of stage-discharge and discharge-loads rating curve. By using the methods above, I've evaluated the water quality (WQ) of the JSW if it is satisfied with the standard target. I've collected the data of BOD and T-P from the JSW every 8 days for the duration of 12 months. And then, I've schematized the data upon the load duration curve and the results showed me that the WQ of JSW was satisfied with the standard target. I've also collected the same data every each day for the duration of 12 months from JSW and have schematized the data again. And the results showed that it also was satisfied with the standard target. To be concluded, I've determined that point pollution sources of JSW gives more significant impacts to the WQ than non-point pollution sources of JSW and hence, as time goes, point pollution sources will keep depriciating the WQ of JSW. Therefore, further efforts will be required to JSW to maintain the WQ.

• Journal of Environmental Science International
• /
• v.26 no.8
• /
• pp.939-953
• /
• 2017

For the development of flow duration curves for the management of 41 Total Maximum Daily Load (TMDL) units of the Nakdong River basin, first, an equation for estimating daily flow rates as well as the level of correlation (correlation and determination coefficients) was extrapolated through regression analysis of discrete (Ministry of Environment) and continuous (Ministry of Land, Infrastructure and Transportation) measurement data. The equation derived from the analysis was used to estimate daily flow rates in order to develop flow duration curves for each TMDL unit. By using the equation, the annual flow duration curves and flow curves, for the entire period and for each TMDL unit of the basin, were developed to be demonstrated in this research. Standard flow rates (abundant-, ordinary-, low- and drought flows) for major flow duration periods were calculated based on the annual flow duration curves. Then, the flow rates, based on percentile ranks of exceedance probabilities (5, 25, 50, 75, and 95%), were calculated according to the flow duration curves for the entire period and are suggested in this research. These results can be used for feasibility assessment of the set values of primary and secondary standard flow rates for each river system, which are derived from complicated models. In addition, they will also be useful for the process of implementing TMDL management, including evaluation of the target level of water purity based on load duration curves.