• Korean Journal of Agricultural Science
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• v.37 no.2
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• pp.285-293
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• 2010

To secure instream flow at the Yudeung urban stream reach of Daejeon city in South Korea, Yudeung upstream diversion was designed with total water storage of $59{\times}10^4m^3$, and the upstream Seongol reservoir was planned to raise the bank with various sizes. Downstream streamflows were simulated by considering outflows from upstream diversion and reservoir, and after then flow durations were analyzed and compared with flows of no reservoir condition. In case of no diversion or reservoir upstream, flow durations were $1^{st}$ flow of $84.72m^3/s$, $95^{th}$ flow of $2.10m^3/s$, $185^{th}$ flow of $0.92m^3/s$, $275^{th}$ flow of $0.42m^3/s$, and $355^{th}$ flow of $0.31m^3/s$. In case of upstream diversion, flow durations were $1^{st}$ flow of $94.38m^3/s$, $95^{th}$ flow of $2.96m^3/s$, $185^{th}$ flow of $1.22m^3/s$, $275^{th}$ flow of $0.50m^3/s$, and $355^{th}$ flow of $0.35m^3/s$. The increase flow rates were $0.04m^3/s$ in $355^{th}$ flow, $0.08m^3/s$ in $275^{th}$, and $0.30m^3/s$ in 185th. In case of Seongol reservoir with effective storage capacities of $365{\times}10^4m^3$, $544{\times}10^4m^3$, $750{\times}10^4m^3$, and $992{\times}10^4m^3$, flow durations were $85.5{\sim}83.9m^3/s$ on $1^{st}$ flow, $2.85{\sim}2.57m^3/s$ on $95^{th}$ flow, $1.16{\sim}1.27m^3/s$ on $185^{th}$ flow, $0.64{\sim}0.99m^3/s$ on $275^{th}$ flow, and $0.56{\sim}0.94m^3/s$ on $355^{th}$ flow. The increase flow rates were $0.25{\sim}0.63m^3/s$ in $355^{th}$ flow, $0.22{\sim}0.57m^3/s$ in $275^{th}$, and $0.24{\sim}0.35m^3/s$ in $185^{th}$. The more the sizes of upstream reservoirs increased, the $1^{st}$ and $95^{th}$ flows decreased in which coefficients of determination were 0.92, 0.99, respectively and the $185^{th}$, $275^{th}$, and $355^{th}$ flows increased in which coefficients of determination were 0.93 to 0.99.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.395-398
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• 2011

This paper introduces stochastic cash-flow modeling integrated with simulation based scheduling. The system makes use of CPM schedule data exported from commercial scheduling software, computes the best fit probability distribution functions (PDFs) of historical activity durations, assigns the PDFs identified to respective activities, simulates the schedule network, computes the deterministic and stochastic project cash-flows, plots the corresponding cash flow diagrams, and estimates the best fit PDFs of overdraft and net profit of a project. It analyzes the effect of different distributions of activity durations on the distribution of overdrafts and net profits, and improves reliability compared to deterministic cash flow analysis.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.30 no.2
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• pp.85-92
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• 2016

The paper presents a method to assess system voltage sag performance considering sag durations as well as magnitudes. In general, voltage sag assessment for large power systems is performed only considering sag magnitudes at sensitive load points. However some equipment can be affected by certain sag durations. The duration of the voltage sag is depend on the time of fault current flow in the system. Therefore, the duration can be determined by analyzing the operating characteristic of the protection system. In this paper, an effective method to evaluate sag durations regarding the characteristics and failure rates of the protection system is described. The proposed method can be used to assess the long-term performance of the voltage sags in large power system.

• Journal of the Korean Chemical Society
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• v.4 no.1
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• pp.1-6
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• 1957

The mobilities and the electrophoretic phenomena of human serum albumin, and of horse serum albumin, etc., on paper were reported, but there is no information about the mobility and the electrophoretic phenomena of ovalbumin. In this study they are determined and considered at various time durations. The mean value of this mobility is compared with the value determined by the electrophoresis in solution. Also, the mobilities of the electroendosmotic flow, which affect on the mobility seriously, are determined at various time durations. Apparatus and method used, are a closed system type and a method with electrode vessels. It is concluded that: 1) The mobilities of ovalbumin have the nearly constant mobilities at six and eight hours of time durations, but it decreases at ten hours of long time duration. Their mean value is (0.243 ${\pm}$ 0.003)cm./hr./v./cm. toward anode at pH 8.0. 2) Under these experimental conditions, ovalbumin cannot be separated into three fractions (A1, A2, A3) on paper. 3) Most of the factors, which affect on the mobility, are fixed by the initial experimental conditions, but the electroendosmotic flow due to the characteristic capillarity of paper is measured. Then, the mean value of its mobilities shows the good constancy, and the value is (0.073 ${\pm}$ 0.0003)cm/hr./v./cm. toward cathode at pH 8.0. 4) By the above facts, if the same paper and the same experimental conditions are chosen, it may be preferred to determine the mobility of the electroendosmotic flow once time, even when many observations are required.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.4
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• pp.381-387
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• 2000

An experimental study on the stratified fluids was carried out to investigate the flow characteristics, heat transfer through the interface of fluids, and the applications of thermal behaviors in the square cavity. The same volume of water and silicon oil was filled in it. The experiments were performed with the variations of initial temperatures and cooling surface temperatures. And the effect of vertical or horizontal cooling surface positions in the square cavity was investigated. When the cooling surface temperatures were $-4^{\circ}C$ , the supercooling phenomena were observed for both cases of cooling surface positions in the full region regardless of the initial temperature of fluid. In the square cavity with horizontal cooling surfaces, the lower the initial temperatures were, the longer the supercooling durations were, and with vertical cooling surface the lower the initial temperatures were, the shorter the supercooling durations were.

• Journal of Mechanical Science and Technology
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• v.14 no.8
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• pp.861-866
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• 2000

Flow induced shape change is important for spatial interpretation of vascular response and for understanding of mechanotransduction in a single cell. We investigated the possible shapes of endothelial cell (EC) in a mathematical model and compared these with experimental results. The linearized analytic solution from the sinusoidal wavy wall and Stokes flow was applied with the constraint of EC volume. The three dimensional structure of the human umbilical vein endothelial cell was visualized in static culture or after various durations of shear stress (20 $dyne/cm^2$ for 5, 10, 20, 40, 60, 120min). The shape ratio (width: length: height) of model agreed with that of the experimental result, which represented the drag force minimizing shape of stream-lining. EC would be streamlined in order to accommodate to the shear flow environmented by active reconstruction of cytoskeletons and membranes through a drag force the sensing mechanism.

• Journal of Oral Medicine and Pain
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• v.47 no.3
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• pp.126-134
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• 2022

Purpose: This study aimed to propose an efficient treatment approach for infection with different candida species. Methods: Fifty-three patients who presented with a chief complaint of oral mucosal pain and exhibited positive candida culture findings were divided into two groups (Candida albicans and non-albicans). Pain, mucosal manifestations, salivary flow rates, durations of disease and treatment, and responses to treatment (nystatin and clonazepam) were investigated in both groups. Results: Patients in the C. albicans group exhibited more prominent clinical characteristics (erythematous lesions, tongue coatings, and hyperalgesia) than those in the non-albicans group. In total, 70% of patients in the non-albicans group showed no abnormalities in the oral mucosa. Patients in the C. albicans group showed increased resistance to nystatin treatment compared to those in the non-albicans group, especially with longer disease durations. The patients resistant to nystatin treatment showed positive responses to clonazepam. Conclusions: Patients with oral mucosal pain should be tested for the presence of Candida, even in the absence of mucosal abnormalities, especially those infected with non-albicans species. If no response to antifungal therapy is observed, treatment with clonazepam should be initiated, especially in patients infected with C. albicans.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.243-251
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• 2013

Cash management is a major concern for all contractors in the construction industry. It is arguable that cash is the most critical resource of all. A contractor needs to secure sufficient funds to navigate the project to the end, while keeping an eye on maximizing profits along the way. Past research attempted to address such topic via developing models to tackle the time-cost tradeoff problem, cash flow forecasting, and cash flow management. Yet, little was done to integrate the three aspects of cash management together. This paper, as such, presents a comprehensive model that integrates the time-cost tradeoff problem, cash flow management, and cash flow forecasting. First, the model determines the project optimal completion time by considering the different alternative construction methods available for executing project activities. Second, it investigates different funding alternatives and proposes a project-level cash management plan. Two funding alternatives are considered; they are borrowing and company own financing. The model was built as a combinatorial optimization model that utilizes ant colony search capabilities. The model also utilizes Microsoft Project software and spreadsheets to maintain an environment that incorporates activities, their durations, and other project data, in order to estimate project completion time and cost. Ant Colony Optimization algorithm was coded as a Macro program using VBA. Finally, an example project was used to test the developed model, where it acted reliably in maximizing the contractor's profit in the test project.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.6 no.3
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• pp.63-74
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• 1986

A methodology for the probabilistic determination of active storage capacity of an impounding reservoir is proposed with due considerations to the durations and return periods of the low flow series at the reservoir site. For more reliable probabilistic analysis the best-fit stochastic generation model of Monte Carlo type was first selected for the generation of monthly flow series, the models tested being the Month Carlo Model based on the month-by-month flow series (Monte Carlo-A Type), Monte Carlo Model based on the standardized sequential monthly flow series (Monte Carlo-B Type), and the Thomas-Fiering Model. Monte Carlo-B Model was final1y selected and synthetic monthly flows of 200 years at Hong Cheon dam site were generated. With so generated 200 years' monthly flows partial duration series of low flows were developed for various durations. Each low flow series was further processed by a nonsequential mass analysis for specified draft rates. This mass analysis furnished the storage-draft-recurrence interval relationship which gives the reservoir storage requirement for a specified water demand from the reservoir during a drought of given return period. Illustrations are given on the application of these results in analyzing the water supply capacity of a particlar reservoir, existing or proposed.

• YAKHAK HOEJI
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• v.23 no.1
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• pp.31-39
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• 1979

Bethanidine was administered into the lateral ventricle of the rabbit brain for the investigation of the effect on the renal function in doses ranging from 0.1 to 1.0mg/kg. In a dose of 0.1 mg/kg, bethanidine did not exhibit significant changes on the renal function of the rabbit, on the other hand, in the doses of 0.3 and 1.0mg/kg bethanidine elicited the reduction of renal plasma flow and glomerular filtration rate with a marked antidiuresis, at the same time bethanidine produced the decrement of urinary sodium and potassium excretion. After intravenous pretreatment of phentolamine, intraventricular bethanidine in a dose of 0.3mg/kg did not produced the antidiuresis and the decrement of urinary sodium and potassium excretion, wherease renal plasma flow and glomerular filtration rate reduced as before of phentolamine pretreatment although the durations of their reduction were shortened. These observations suggest that bethanidine induces the antidiuresis through the centrally mediated mechanism which interposed other factors in addition to sympathetic stimulation affected by phentolamine, alpha adrenergic blocking agent.