• Title/Summary/Keyword: periods

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A Study on Parameter Estimation for SWAT Calibration Considering Streamflow of Long-term Drought Periods (장기 가뭄기간의 유출량을 고려한 SWAT 보정 매개변수 추정 연구)

  • Kim, Da Rae;Kim, Seong Joon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.59 no.2
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    • pp.19-27
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    • 2017
  • Recently, the hydrological model Soil Water Assessment Tool (SWAT) has been applied in many watersheds in South Korea. This study estimated parameters in SWAT for calibrating streamflow in long-term drought periods. Therefore, we focused on the continuous severe drought periods 2014~2015, and understand the model calibrated parameters. The SWAT was applied to a $366.5km^2$ Gongdo watershed by using 14 years (2002~2015) daily observed streamflow (Q) including two years extreme drought period of 2014~2015. The 9 parameters of CN2, CANMX, ESCO, SOL_K, SLSOIL, LAT_TIME, GW_DELAY, GWQMN, ALPHA_BF were selected for model calibration. The SWAT result by focusing on 5 normal years (2002~2006) calibration showed the 14 years average Nash-Sutcliffe model efficiency (NSE) for Q and 1/Q with 0.78 and 0.58 respectively. On the other hand, the 14 years average NSEs of Q and 1/Q by focusing on 2 drought years (2014~2015) calibration were 0.86 and 0.76 respectively. Thus, we could infer that the SWAT calibration trial by focusing on drought periods data can be a good approach to calibrate both high flow and low flow by controlling the 9 drought affected parameters.

Study on the Apparent Absorption Rate of Calcium in College Women (여대생의 칼슘흡수율에 관한 연구)

  • Lee, Hyun-Ok
    • Journal of Nutrition and Health
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    • v.13 no.3
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    • pp.134-138
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    • 1980
  • The present study was designed to investigate the effects of the level of calcium intake on it's apparent absorption rate in college women. Six college girls aged 19 to 20 were fed general dormitary meals containing approximately500mg of calcium for one week and thereafter, the experimental diets containing about 800mg of calcium were given for one week. Average values for calcium intake, fecal excretion of calcium, and apparent absorption rateof calcium in both periods were determined and these values for two periods were compared by using t-test. 1) Average intakes of calcium, protein, and fat of the subjects during the period of experimental diet were significantly higher than those of general diet period. 2) Higher consumption of three food groups; meat, poultry, and fishes, fruits and vegetables, and fats and oils were noted during experimental period. However, there was no significant difference in the consumption of cereals and milk groups during these two periods. 3) The apparent absorption rate of calcium during the experimental period was higher (64%) than the one for general diet period (56%). It was noteworthy that average calcium intakes was higher during the experimental diet period (785mg) than 536mg for general diet period while the fecal excretions of calcium in both periods were not significantly different.

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Mathematical Basis for Establishing Reasonable Objective Periodsin Zero Accident Campaign (무재해 목표기간 재설정의 수리적 근거)

  • Lim, Hyeon-Kyo;Kim, Young-Jin;Chang, Seong-Rok
    • Journal of the Korean Society of Safety
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    • v.25 no.4
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    • pp.61-67
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    • 2010
  • Though "Zero Accident Campaign" is a desirable campaign for industrial accident prevention and reducing victims, the number of industrial enterprises has been decreasing abruptly in recent years. One of the reasons for this phenomenon may be attributed to irrationality of 'target accident-free time periods' established by related organizations. This study was carried out to develop a new rational scheme for the campaign. Therefore, for a numerical basis, Poisson process was introduced, and problems induced by current target periods were analyzed mathematically one by one. As a result, it was verified that current target periods were uneven since the probability that manufacturing plants get them would be different form industry to industry. To develop countermeasures, a brand new method were suggested in this research. The first characteristic was that group classification should be based upon average accident rates resulted from past several years, and the second was that adjustment probability which can make the target acquisition probability even. About the suggested method, a questionnaire survey was conducted. To make a conclusion, most manufacturing plants agreed with the suggested method such high affirmative portion that the suggested method would be expected to help promote the campaign again.

A Study on the Applicability of Non-Supporting System Forms for Single Face Walls in Underground Construction (지하층 합벽 무지주 시스템 거푸집의 적용성에 관한 연구)

  • Kim, Jae Yeob;An, Sung-Hoon;Sohn, Young-Jin
    • KIEAE Journal
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    • v.8 no.2
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    • pp.87-92
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    • 2008
  • Underground building constructions are recently more important because the ratio of underground area is increasing in the huge and high-rise building construction projects. For reducing the total building construction periods, it is required to reduce not only the over-ground structural work periods but also the underground structural work periods. Therefore, this study is proposed the non-supporting system forms for single face walls in underground building construction by one of the methods for reducing the underground structural work periods and investigated the applicability of the non-supporting system forms by analyzing the case-study in civil construction project. In regard of construction duration, the results of analyzing the case-study showed that the non-supporting system forms are better than the euro forms with soldier system for single face walls in underground building construction. In addition, it is showed that the cost of these two forms is similar and usage the working space and safety in non-supporting system forms are better that those of the euro forms with soldier system, too.

Types and Characteristics of Chinese Hyangnang (중국 향낭의 유형과 특성)

  • Lee, Joo-Young;Lee, Kyung-Hee;Kwon, Young-Suk
    • Journal of the Korean Society of Costume
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    • v.56 no.8 s.108
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    • pp.1-14
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    • 2006
  • This study is to examine the Hyangnag used in China. Results of the study can be described as below. 1. Hyangnang was also called Hyangdae, Hyanghapo, Hunnang and Chunnang. Perfumes were used to make the body and clothes diffuse a good fragrance. And Perfumes were used to prevent insects and remove related pollutions. It was possible to prevent insects when perfumes were burnt out. 2. In the Han, Song, Yao and Win periods, Hyangnang had Cylinderical, Rectangular, Cylinderical and Rectangular, Circular and Calabach types. These various types were developed into one, Norigae type, in the period of Ching. 3. Hyangnang were decorated mainly with embroideries, knots and seams. Embroideries were applied always onto the surface of Hyangnang. Knots were used mainly in the Song and Win periods, decorative seams were used mainly in the Ching. 4. From the Han to Yao periods, Hyangnang was made of perforate textiles like na and Sa for practical reasons, making perfume smells more easily diffused. From the Win to Ching periods, Hyangang was made of dense textiles like silk and Dan, which could be easily embroidered for decoration purposes. 5. Hyangnang was often hanged down from the waistband and up onto the fore chest or the elbow, or put into the liner of the sleeve. 6. Hyangnang has immanent implications of symbolism, ideology and aristocraticism.

The Processing of Livestock Waste Through the Use of Activated Sludge - Treatment with Intermittent Aeration Process -

  • Osada, T.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.5
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    • pp.698-701
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    • 2000
  • To prevent surface and underground water pollution, wastewater treatment is essential. Four bench-scale activated sludge units (10 L operational volumes) were operated at 5, 10 and $20^{\circ}C$ for evaluation of treatment efficiencies with typical wastewater from swine housing. The units were set for a 24-hour cycle. As compared to the conventional process, high removal efficiencies for organic substances, nitrogen and phosphorus in swine wastewater were obtained simultaneously with an intermittent aeration process (lAP). The NOx-N produced during an aeration period was immediately reduced to nitrogen gas (e.g. $N_2$ or $N_2O$) in the subsequent non-aeration periods, and nitrification in aeration periods occurred smoothly. Under these conditions, phosphorus removal occurred with the release of phosphorus during the non-aeration periods followed by the excess uptake of phosphorus in the activated sludge during aeration periods. It was confirmed that the lAP had a better ability to remove pollutants under both low temperatures and high nitrogen loading conditions than the ordinary method did. In addition to that, the total emission of $N_2O$ from lAP was reduced to approximately 1/50 of the conventional process for the same loading. By adopting an adequate aeration programme for individual swine wastewater treatment, this system will provide a promising means for nitrogen and phosphorus control without pH control or addition of methanol.

A study on the Innovation method of Metro EMU Maintenance (도시철도 전동차 정비 이론 및 개선 방향 연구)

  • Choi, Yong-Woon
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.1864-1870
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    • 2007
  • The inspection periods for the metro EMU maintenances vary variously according to the countries and railway operators. And the inspection systems vary according to the safety, economical, technical aspects, and also the social environments like passengers and maintenance qualities, etc. Also, in economic point of view, maintenance requires the man power, facilities, equipments, purchasing of parts and the loss of not being in revenue service during the maintenance period. Recently, there is a tendency that the inspection periods are extended gradually owing to the increased reliabilities of the equipments and parts of EMUs. Even if it is the EMUs that are already be in service, once the inspection method is innovated, the inspection time can be reduced. The inspection management innovation scheme includes such methods as the complete module to module replacement when trouble shooting a faulty parts before putting the EMU back to revenue service, the replacements of parts in complete set unit for the heavy maintenance, the establishments of exchange periods for the wasting parts, modernization of inspection equipments, introduction of RAMS for the reliability improvement and computerization of EMU maintenance management, etc. I think it is possible to optimize the inspection scopes and periods per parts and equipments by the introduction of RAMS.

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A Study on the Women's Clothing Discard Behavior (성인 여성의 의복 폐기에 관한 연구)

  • 유연실
    • Journal of the Korean Society of Clothing and Textiles
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    • v.20 no.1
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    • pp.142-156
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    • 1996
  • The purposes of this study were to examine the reason, = of clothing discard and to investigate the influences of demographic and clothing variables on the clothing discard behavior Data were collected from 610 women who lived in Seoul and Kwangjoo. By means of factor analysis, 6 general factors of clothing discard reason.; were extracted The 6 factors were named as dissatisfaction with appropriateness, physically worn out, dissatisfaction with clothing quality, fashion change, boredom, inconvinience. Among the five clothing items (suits or one pieces, jackets, jumpers, shirts or blouses, skirts or pants), there existed differences in the reason factors of clothing discard The relationships between clothing discard behavior (reason factors of clothing discard, peviods of clothing utilization) and variables like user's age, degrees of satisfaction with clothing, clothing items were also examined. There existed significant differences among the age groups and the groups classified by clothing satisfaction degrees in the reason factors of clothing discard and in the Periods of clothing utilization. Periods of clothing utilization were also differed by the clothing items. As user's a age grew older, periods of clothing utilization increased and the rates of clothing discard because of dissatisfaction with appropriateness, and dissatisfaction with clothing quality, boredom, inconvinience factors were decreased. As the degrees of satisfaction with clothes increased, the periods of clothing utilization also increased and the rates of clothing discard because of dissatisfaction with appropriateness, and dissatisfaction with clothing quality, inconvinience factors decreased. And the rates of clothing discard because of physically worn out factor increased.

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Quantitative Comparisons on the Intrinsic Features of Foreign Exchange Rates Between the 1920s and the 2010s: Case of the USD-GBP Exchange Rate

  • Han, Young Wook
    • East Asian Economic Review
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    • v.20 no.3
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    • pp.365-390
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    • 2016
  • This paper quantitatively compares the intrinsic features of the daily USD-GBP exchange rates in two different periods, the 1920s and the 2010s, under the same freely floating exchange rate system. Even though the foreign exchange markets in the 1920s seem to be much less organized and developed than in the 2010s, this paper finds that both the long memory volatility property and the structural break appear to be the common intrigue features of the exchange rates in the two periods by using the FIGARCH model. In particular, the long memory volatility properties in the two periods are found to be upward biased and overstated because of the structural breaks in the exchange markets. Thus this paper applies the Adaptive-FIGARCH model to consider the long memory volatility property and the structural breaks jointly. The main finding is that the structural breaks in the exchange markets affect the long memory volatility property significantly in the two periods but the degree of the long memory volatility property in the 1920s is reduced more remarkably than in the 2010s after the structural breaks are accounted for; thus implying that the structural breaks in the foreign exchange markets in the 1920s seem to be more significant.

New Randomness Testing Methods using Approximate Periods (근사 주기를 이용한 새로운 랜덤성 테스트 기법)

  • Lim, Ji-Hyuk;Lee, Sun-Ho;Kim, Dong-Kyue
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.6
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    • pp.742-746
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    • 2010
  • In this paper, we propose new randomness testing methods based on approximate periods in order to improve the previous randomness testing method using exact pattern matching. Finding approximate periods of random sequences enables us to search similarly repeated parts, but it has disadvantages since it takes long time. In this paper we propose randomness testing methods whose time complexity is O($n^2$) by reducing the time complexity of computing approximate periods from O($n^3$) to O($n^2$). Moreover, we perform some experiments to compare pseudo random number generated by AES cryptographic algorithms and true random number.