• ETRI Journal
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• v.22 no.4
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• pp.40-50
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• 2000

We apply a "sliding-window" Maximum Likelihood(ML) estimator to estimate traffic parameters On-Off source and develop a method for estimating stochastic predicted individual cell arrival rates. Based on these results, we propose a simple Connection Admission Control(CAC)scheme for delay sensitive services in broadband onboard packet switching satellite systems. The algorithms are motivated by the limited onboard satellite buffer, the large propagation delay, and low computational capabilities inherent in satellite communication systems. We develop an algorithm using the predicted individual cell loss ratio instead of using steady state cell loss ratios. We demonstrate the CAC benefits of this approach over using steady state cell loss ratios as well as predicted total cell loss ratios. We also derive the predictive saturation probability and the predictive cell loss ratio and use them to control the total number of connections. Predictive congestion control mechanisms allow a satellite network to operate in the optimum region of low delay and high throughput. This is different from the traditional reactive congestion control mechanism that allows the network to recover from the congested state. Numerical and simulation results obtained suggest that the proposed predictive scheme is a promising approach for real time CAC.

• The Korean Journal of Health Service Management
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• v.4 no.1
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• pp.99-110
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• 2010

The purpose of this study is to analyze the internal factors that influence the performance of local government hospitals in Korea. Out of 34 Local Government hospitals, 6 hospitals were selected as sample hospitals. Then hospitals were divided into two groups(3 hospitals each), one of which was profit-making and the other loss-making. The criteria in selecting profit or loss-making hospitals was Normal Profit to Total Assets. The major findings of this study were as follows : The headcount per 100 bed of the profit-making hospitals was 8.8 persons less than the loss-making hospitals and the ratio of payroll expenses to total revenue 14.7% less. Inpatient bed occupancy ratio of the profit-making hospitals was 92.8%. This result is higher 21.8% than loss-making hospitals.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.161-164
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• 2006

Three-dimensional flow and aerodynamic loss in the tip-leakage flow region of a high-turning first-stage turbine rotor blade with a squealer tip have been measured with a straight miniature five-hole probe for the tip gap-to-chord ratio, h/e, of 2,0%. This squealer tip has a indent-to-chord ratio, $h_{st}/c$, of 5.5%. The results are compared with those for a plane tip ($h_{st}/c\;=\;0.0%$). The squealer tip tends to reduce the mass flow through the tip gap and to suppress the development of the tip-leakage vortex. Therefore, it delivers lower aerodynamic loss in the near-tip region than the plane tip does. At the mid-span, however, the aerodynamic loss has nearly the same value for the two different tips.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.9 s.252
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• pp.913-920
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• 2006

Three-dimensional flow and aerodynamic loss in the tip-leakage flow region of a high-turning first-stage turbine rotor blade with a squealer tip have been measured with a straight miniature five-hole probe for the tip gap-to-chord ratio, h/c, of 2.0%. This squealer tip has a indent-to-chord ratio, $h/{st}/c$, of 5.5%. The results are compared with those for a plane tip $(h_{st}/c=0.0%)$. The squealer tip tends to reduce the mass flow through the tip gap and to suppress the development of the tip-leakage vortex. Therefore, it delivers lower aerodynamic loss in the near-tip region than the plane tip does. At the mid-span, however, the aerodynamic loss has nearly the same value for the two different tips.

• Journal of the Korean Society of Safety
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• v.16 no.2
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• pp.63-68
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• 2001

In this study the main elements which can be commonly adopted to every kind of business are selected through the research, case-study, benchmarking common items of a direct or indirect loss cost. As a result of the development of a program for evaluating loss cost a case or accumulated data can be easily managed through estimating the direct and indirect loss cost as tell as the ratio between directs and indirect cost. The program is fit to case-study and we are compared direct cost with indirect cost. Automatically, this program showed ratio between directs and indirect cost for style, scale of accident The person in charge of safety and hygiene can have better chances to get into management also the owner or the CEO can recognize the importance of management of safety and hygiene. So this can guide the company to invest in a prevention of disaster and to adopt a safety and hygiene management promote the prevention activity of a company, and finally decrease the accident rate in the country.

• ETRI Journal
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• v.41 no.5
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• pp.637-647
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• 2019

Separating highly correlated users can reduce the loss caused by spatial correlation (SC) in multiuser multiple-input multiple-output (MU-MIMO) systems. However, few accurate analyses of the loss caused by SC have been conducted. In this study, we define signal-to-interference-plus-noise ratio (SINR) loss to characterize it in multiuser multiple-input single-output (MU-MISO) systems, and use coefficient of correlation (CoC) to describe the SC between users. A formula is deduced to show the accurate relation between SINR loss and CoC. Based on this relation, we propose a user selection method that utilizes CoC to minimize the average SINR loss of users in massive MU-MISO systems. Simulation results verify the correctness of the relation and show that the proposed user selection method is very effective at reducing the loss caused by SC in massive MU-MISO systems.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.6
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• pp.989-999
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• 2017

In this study, hydraulic experimental studies were conducted to estimate the empirical formulas of loss coefficient, which is necessary to calculate the energy loss occurred in the dividing channel junction of sewer system. The experimental apparatus was consisted of two outflow conduit with a $90^{\circ}$ angle to the inlet conduit, and the pressure and velocity heads are measured to analyze the energy losses in the branch. The measurements of the hydraulic grade line show that the hydraulic grade line was steeply descended at the dividing point due to the head loss, and the decreasing amount of velocity head increased with the increase of flowrate ratio. The head loss exponentially increased in the outlet with larger runoff as the increase of flowrate ratio and Froude number, and the head loss coefficient also increased. On the other hands, the head loss coefficients decreased in the outlet with smaller runoff as the increase of the flowrate ratio and Froude number. Using the experimental results, the empirical formulas of loss coefficient was suggested for each outlet, and the error of empirical formula was 3.91 and 5.19%, respectively. Furthermore, the total head loss coefficient calculated by the two empirical formulas was compared with the experimental results, and the error was 3.62%.

• Journal of Ginseng Research
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• v.29 no.2
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• pp.113-118
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• 2005

This study was to examine the effect of the opening ratio (area of spile hole/total surface area) of plastic container and storage temperature on physicochemical changes of fresh ginseng. At room temperature ($19\~23^{\circ}C$, RH $40\~61\%$), fungi and spoilage were observed 4 and 10 days, respectively after storing the fresh ginseng in a closed container. In storage container with $1\%$ opening ratio, fungi appeared 8 days after storage. In the container with $5\%$ and $10\%$ opening ratio, fresh ginseng showed excessive loss of moisture on the surface only after 4 days. The weight loss was most remarkable in the container with 5 and $10\%$ opening ratio. Content of maltose and sucrose decreased gradually in accordance with storage time but the extent of decreasing ratio was less significant in the container with lower opening ratio. At low temperature $(4\~9^{\circ}C,\;RH\;72\~92\%)$, no fungi but $10\%$ loss of weight was observed in the container with $5\%$ and $10\%$ opening ratio after 12 days storage. But in the tightly closed container and $1\%$ opening ratio for spiting, fresh ginseng showed good appearance even after 30 days of storage. Free sugars, especially maltose revealed gradual decrease but sucrose gradually increase following decrease at the beginning. This result suggests that storage condition of low temperature and opening ratio of plastic box less than $1\%$ can extend storage span of fresh ginseng significantly.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.05b
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• pp.61-64
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• 2009

This study is reviewed fire resistance characteristics of high strength concrete according to changes in PP fiber mixing ratio and type of fine aggregate, and the results can be summarized as follows. As fire resistance characteristics, all plain crushed sands prevented spalling regardless of increase in mixing ratio of PP fiber. Mixtures other than the plain showed satisfactory spalling prevention when 0.05 % or more of PP fiber was mixed. After the fire resistance experiment, the plain showed 5.5 % of mass loss rate when fiber was not mixed and others could not be measured. According to increase in mixing ratio of fiber, river sand with fineness modulus of 2.2 showed most satisfactory result of 34 %${\sim}$42 %. Mass loss rate after fire resistance experiment was most satisfactory at about 10 % in the plain crushed sand without mixing of fiber, and all other mixes with 0.05 % PP fiber or more showed 5${\sim}$10 % loss rate.

• The Journal of the Korean life insurance medical association
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• v.27 no.2
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• pp.80-84
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• 2008

Now, we have experienced that the loss ratio of cancer insurance with prevalence of cancer increased. The insurance companies interest how the loss ratio of cancer insurance decrease. To decrease the loss of ratio of cancer, underwriting is very important. The underwriting of cancer are very important factors which are family history, habitual behavior and past history. We have spend the most of time under the occupational situation. Occupation may be very important factor causing cancer. But we neglect the occupation history. This article show how the underwriting of the occupational cancers in the field of occupation are managed Generally, Occupational cancers show special characteristic features. We know the characteristics of occupational cancer under the variety of occupation. For the underwriting of occupational cancer in Korea, we also understand the epidemiology of Korean occupational cancer with the varieties of occupation This article shows the characteristics of occupational cancer and epidemiology of Korean occupational cancers.