• 한국수자원학회논문집
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• 제57권4호
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• pp.289-300
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• 2024

본 연구의 목적은 물리적 분포형 유출 모형인 GRM (Grid based rainfall-Runoff Model)을 이용하여 댐 유입량을 모의함으로써 연속형 모의에 대한 GRM 모형의 적용성을 평가하는 것이다. GRM 모형은 기존에 강우-유출 사상의 모의를 위해서 개발되었으나, 최근에 연속형 모의가 가능하도록 개선되었다. 대상 유역은 충주댐 유역, 안동댐 유역, 용담댐 유역, 섬진강댐 유역이며, 500 m × 500 m의 공간 해상도로 유출 모형을 구축하였다. 모의 기간은 21년(2001년~2021년)이다. 모의결과의 평가는 17년 기간(2005년~2021년)에 대해서 수행하였으며, 17년 전체 자료(total duration), 풍수기(6월~9월, wet season), 갈수기(10월~5월, dry season)의 3개 자료 기간으로 구분하고, 각 댐의 관측된 일유입량과 비교하였다. 모의결과의 적합도 평가는 Nash-Sutcliffe efficiency 계수(NSE), Kling-Gupta efficiency 계수(KGE), 상관계수(CC), 총용적 오차(VE)를 사용하였다. 모의된 댐 유입량의 평가결과 total duration과 wet season에서 관측자료를 잘 재현할 수 있었으며, dry season에서도 저유량 자료의 불확실성을 고려할 때 양호한 모의결과를 나타내었다. 연구결과 GRM 모형의 연속형 모의기법은 적절히 구현된 것으로 판단되었으며, 본 연구의 댐 유입량 모의에 충분히 적용성이 있는 것으로 나타났다.

• Water Engineering Research
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• 제1권2호
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• pp.147-158
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• 2000

In this study, we characterized the seasonal variation of rainrate fields in the Han river basin using the WGR multi-dimensional precipitation model (Waymire, Gupta, and Rodriguez-Iturbe, 1984) by estimating and comparing the parameters derived for each month and for the plain area, the mountain area and overall basin, respectively. The first-and second-order statistics derived from observed point gauge data were used to estimate the model parameters based on the Davidon-Fletcher-Powell algorithm of optimization. As a result of the study, we can find that the higher rainfall amount during summer is mainly due to the arrival rate of rain bands, mean number of cells per cluster potential center, and raincell intensity. However, other parameters controlling the mean number of rain cells per cluster, the cellular birth rate, and the mean cell age are found invariant to the rainfall amounts. In the application to the downstream plain area and upstream mountain area of the Han river basin, we found that the number of storms in the mountain area was estimated a little higher than that in the plain area, but the cell intensity in the mountain area a little lower than that in the plain area. Thus, in the mountain area more frequent but less intense storms can be expected due to the orographic effect, but the total amount of rainfall in a given period seems to remain the same.

• Asian-Australasian Journal of Animal Sciences
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• 제24권9호
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• pp.1192-1198
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• 2011

Peri-partum metabolic profile was evaluated in winter and summer calving, with 15 Murrah buffaloes in each seasonal group. In summer calvers, significantly lower values were observed for blood plasma urea nitrogen (BUN) at day 30 pre-partum (p<0.05), on calving day (p<0.05) and at all other stages (p<0.01); plasma non-esterified fatty acids (NEFA) values were significantly lower on day 30 pre-partum (p<0.01) and on day 60 post-partum (p<0.05). This was associated with significant reduction in days to first service (DFS) and service per conception (SPC) and an overall better reproductive performance in terms of service period, risk to first service on days 60, 90 and >90, and pregnancy risk to first service up to days 60 and 90. This may be attributed to better pre-partum nutritional status. Cervical and uterine involution were completed in fewer days, involutional changes took place at a faster pace and there were a lower number of abnormal involutional changes in winter compared to summer season. This may be attributed to better post-partum nutrition and less environmental stress. However, validation requires further targeted cohort investigation with a large sample size.

• International Journal of Reliability and Applications
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• 제15권2호
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• pp.125-150
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• 2014

Accelerated life tests (ALTs) are extensively used to determine the reliability of a product in a short period of time. Test units are subject to elevated stresses which yield quick failures. ALT can be carried out using constant-stress, step-stress, progressive-stress, cyclic-stress or random-stress loading and their various combinations. An ALT with linearly increasing stress is ramp-stress test. Much of the previous work on planning ALTs has focused on constant-stress, step-stress, ramp-stress schemes and their various combinations where the stress is generally increased. This paper presents an optimal design of ramp soak-stress ALT model which is based on the principle of Thermal cycling. Thermal cycling involves applying high and low temperatures repeatedly over time. The optimal plan consists in finding out relevant experimental variables, namely, stress rates and stress rate change points, by minimizing variance of reliability function with pre-specified mission time under normal operating conditions. The Burr type XII life distribution and time-censored data have been used for the purpose. Burr type XII life distribution has been found appropriate for accelerated life testing experiments. The method developed has been explained using a numerical example and sensitivity analysis carried out.

• Asian Pacific Journal of Cancer Prevention
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• 제17권12호
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• pp.5057-5061
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• 2016

The present study was conducted to assess error rates with diagnosis using intra-operative frozen sections, and to indicate ways to increase overall performance. Over a period of two years, 227 cases were biopsied intra-operatively. Errors were observed in 14 cases. Four of these were sampling errors, one by a pathologist and three by surgeons. In seven cases incorrect interpretations were made. Epithelial dysplasia was observed on definitive histology in two cases which was not reported intra-operatively. One case was of ectopic thyroid. In cases of oral cancer where sentinel lymph nodes were sampled, immunohistochemistry for cytokeratin was performed to facilitate identification of micrometastasis. Only single case displayed tumor deposits which was not evident morphologically. Resection margins were reported in seventy eight cases. Some 18% (14/50) benefited from revision of margins; overall sensitivity of intra-operative frozen sections for marginal status was 71.4%, with a specificity of 90.3%. Overall sensitivity was 75% and specificity was 97.5%. Careful observation, pathologist experience and knowledge of limitations help in improving the overall diagnostic outcome.

• Asian Pacific Journal of Cancer Prevention
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• 제14권5호
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• pp.3315-3318
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• 2013

Gall bladder carcinoma is the most common cancer of biliary tree, characterized by rapid progression and a very high mortality rate. Detection at an early stage, however, is indicative of a very good prognosis and prolonged survival. The practice of histopathological examination of gall bladder specimens removed for clinically benign conditions and its usefulness has been a subject of controversy. The present prospective study was carried out over a period of four years in order to find out the incidence of unsuspected gallbladder carcinoma in cholecystectomy specimens received in our histopathology laboratory and to analyze their clinico-pathological features. A total of 4,115 cases were examined. Incidentally detected cases comprised 0.44%, which accounted for 72% of all gall bladder carcinomas detected. The majority were in an early, surgically resectable stage. From the results of this study we recommend that in India and other countries with relatively high incidences of gall bladder carcinoma, all cholecystectomy specimens should be submitted to histopathology laboratory, as this is the only means by which malignancies can be detected at an early, potentially curable stage.

• Advances in Traditional Medicine
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• 제8권1호
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• pp.39-46
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• 2008

In the Indian traditional medicine, Lippia nodiflora (Verbenaceae) whole plant is claimed to possess powerful diuretic activity. However, the diuretic potential of this plant is not yet investigated. The aim of this study was to evaluate the diuretic potential of methanol extract of Lippia nodiflora (MELN) in rats. Control (0.9% saline solution, 25 ml/kg, b.w) or urea (1 g/kg b.w) or frusemide (5 mg/kg b.w) and different concentrations of MELN (200 and 400 mg/kg b.w) were intraperitoneally administered (n = 6 per each treatment group) to hydrated rats and their urine output was monitored over a period of 5 h and 24 h after drug administration. The diuretic responses with its electrolyte excretion potency of the extract were highly remarkable in comparison with control animals. The extract at doses of 200 and 400 mg/kg shows a significant increase in volume of urine with increase in $Na^{+}$, $Ca^{2+}$ and $Cl^{-}$ excretion accompanied by the excretion of $K^{+}$ in dose dependent manner. This study suggests that the active component(s) in MELN had similar diuretic effect to that of frusemide. These results validate the traditional use of Lippia nodiflora as a diuretic agent.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권1호
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• pp.123-144
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• 2014

Wireless sensor networks are generally deployed for specific applications to accomplish certain objectives over a period of time. To fulfill these objectives, it is crucial that the sensor network continues to function for a long time, even if some of its nodes become faulty. Energy efficiency and fault tolerance are undoubtedly the most crucial requirements for the design of an information extraction protocol for any sensor network application. However, most existing software agent based information extraction protocols are incapable of satisfying these requirements because of static agent itineraries and large agent sizes. This paper proposes an Information Extraction protocol based on Multiple software Agents with Dynamic Itineraries (IEMADI), where multiple software agents are dispatched in parallel to perform tasks based on the query assigned to them. IEMADI decides the itinerary for an agent dynamically at each hop using local information. Through mathematical analysis and simulation, we compare the performance of IEMADI with a well known static itinerary based protocol with respect to energy consumption and response time. The results show that IEMADI provides better performance than the static itinerary based protocols.

• Advances in concrete construction
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• 제10권3호
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• pp.237-245
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• 2020

Past research efforts already established geopolymer as an environment-friendly alternative binder system for ordinary Portland cement (OPC) and recycled aggregate is also one of the promising alternative for natural aggregates. In this study, an effort was made to produce eco-friendly mortar mixes using geopolymer as binder and recycled fine aggregate (RFA) partially and study the resistance ability of these mortar mixes against the aggressive environments. To form the geopolymer binder, 70% fly ash, 30% ground granulated blast furnace slag (GGBS) and alkaline solution comprising of sodium silicate solution and 14M sodium hydroxide solution with a ratio of 1.5 were used. The ratio of alkaline liquid to binder (AL/B) was also considered as 0.4 and 0.6. In order to determine the resistance ability against aggressive environmental conditions, acid attack test, sulphate attack test and rapid chloride permeability test were conducted. Change in mass, change in compressive strength of the specimens after the immersion in acid/sulphate solution for a period of 28, 56, 90 and 120 days has been presented and discussed in this study. Results indicated that the incorporation of RFA leads to the reduction in compressive strength. Even though strength reduction was observed, eco-friendly mortar mixes containing geopolymer as binder and RFA as fine aggregate performed better when it was produced with AL/B ratio of 0.6.

• Nuclear Engineering and Technology
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• 제42권6호
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• pp.690-703
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• 2010

Sampling based uncertainty analysis was carried out to quantify uncertainty in predictions of best estimate code RELAP5/MOD3.2 for a thermal hydraulic test (10% hot leg break LOCA) performed in the Large Scale Test Facility (LSTF) as a part of an IAEA coordinated research project. The nodalisation of the test facility was qualified for both steady state and transient level by systematically applying the procedures led by uncertainty methodology based on accuracy extrapolation (UMAE); uncertainty analysis was carried out using the Latin hypercube sampling (LHS) method to evaluate uncertainty for ten input parameters. Sixteen output parameters were selected for uncertainty evaluation and uncertainty band between $5^{th}$ and $95^{th}$ percentile of the output parameters were evaluated. It was observed that the uncertainty band for the primary pressure during two phase blowdown is larger than that of the remaining period. Similarly, a larger uncertainty band is observed relating to accumulator injection flow during reflood phase. Importance analysis was also carried out and standard rank regression coefficients were computed to quantify the effect of each individual input parameter on output parameters. It was observed that the break discharge coefficient is the most important uncertain parameter relating to the prediction of all the primary side parameters and that the steam generator (SG) relief pressure setting is the most important parameter in predicting the SG secondary pressure.