• Journal of the Society of Disaster Information
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• v.14 no.3
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• pp.262-270
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• 2018

Purpose: This paper investigates and analyzes the loss and damage ratio of maintenance monitoring sensor in metropolitan and high speed railroad tunnel in Korea and abroad. Method: After 5~6 years from the installation, the maintenance monitoring sensor on metropolitan transit tunnels showed the loss and damage ratio from 14.2% to 14.8% in Seoul metro line no. 5, 6, 7, 9, and 13.9% in UK channel tunnel. Based on the result, 15% is thought to be a proper set for the elapsed years, which is 5 years from the installation. Results: The maintenance monitoring sensor on high speed railroad tunnels showed the loss and damage ratio of 60.9% in Ho-Nam high speed railroad on 1 stage after 3 ~ 5 years from the installation, which was approximately 4 times as high as that of Seoul metro line no. 5, 6, 7, 9. Conclusion: Kyung-Bu high speed railroad on 2 stage, after 8~10 years from the installation, showed the loss and damage ratio of 66.8%. Based on the result, it can be inferred that the loss and damage ratio increases drastically after 5~10 years from the installation. Therefore, it is necessary to study on the loss and damage ratio of long term elapsed years, especially more than 10 years from the installation.

• The KSFM Journal of Fluid Machinery
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• v.14 no.1
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• pp.48-54
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• 2011

The effect of channel cutback on three-dimensional flow fields and aerodynamic losses downstream of a cavity squealer tip has been investigated in a turbine rotor cascade for the squealer rim height-to-chord ratio and tip gap height-to-chord ratio of $h_{st}/c$ = 5.51% and h/c = 2.0% respectively. The cutback length-to-camber ratio is changed to be $CB/c_c$ = 0.0, 0.1, 0.2 and 0.3. The results show that longer cutback delivers not only stronger secondary flow but also higher aerodynamic loss in the tip leakage vortex region, meanwhile it leads to lower aerodynamic loss in the passage vortex region. The discharge of cavity fluid through the cutback opening provides a beneficial effect in the reduction of aerodynamic loss, whereas there also exists a side effect of aerodynamic loss increase due to local wider tip gap near the trailing edge. With increasing $CB/c_c$ from 0.0 to 0.3, the aerodynamic loss coefficient mass-averaged all over the measurement plane tends to increase slightly.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.4
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• pp.1363-1375
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• 1996

Oil-film flow visualizations and three-dimensional flow measurements using a five-hole probe have been conducted to investigate three-dimensional flow characteristics and total pressure losses of a row of film-cooling jets injected in spanwise direction. For several span-to-diameter ratios, experiments are performed in the case of three velocity ratios of 0.5, 1.0 and 1.5. The flow measurements show that downstream flow due to the injection is characterized by a single streamwise vortex instead of a pair of counter-rotating vortices, which appear in the case of streamwise injection, and the vortex strength strongly depends on the velocity ratio. Regardless of the velocity*y ratio, presence of the spanwise film-cooling jets always produces total pressure loss, which is pronounced when the velocity ratio is large. It has also been found that the production of the total pressure loss is closely related to the secondary vortical flow. In addition, effects of the span-to-diameter ratio on the flow and total pressure loss are discussed in detail.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.17-20
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• 2000

TCP is ill-suited to real-time multimedia applications. Its bursty transmission, and abrupt and frequent wide rate fluctuations cause high delay jitters and sudden quality degradation of multimedia applications. Deploying non congestion controlled traffic results in extreme unfairness towards competing TCP traffic. Therefore, they need to be enhanced with congestion control schemes that not only am at reducing loss ratios and improve bandwidth utilization but also are fair towards competing TCP connections. This paper proposes a differentiated rate adaptation algorithm based on loss and round trip time. Rate in a sender quickly responds to loss ratio and holds steady state. Additionally, this algorithm reduces loss ratio by loss prediction in a receiver.

• Progress in Superconductivity and Cryogenics
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• v.9 no.1
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• pp.72-75
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• 2007

Magnetization loss of HTS wire is strongly dependent on the critical current density and the aspect ration of the HTS wire. This paper presents the magnetization loss of stacked BSCCO wire and stacked YBCO wires which had different critical current densities. Width of the BSCCO wire was 4mm and widths of two YBCO wires were 4mm and 8mm. Single wire, two stacked three stacked and four stacked wires were fabricated and tested. Ratio of magnetization loss of BSCCO wire to YBCO wire was presented at single wire. For stacked wire, ratio of magnetization loss of single wire to stacked wire was presented. Test results shows that magnetization losses of stacked wires were greater than that of single wire at large high magnetic field above critical magnetic field.

• Journal of the Korean GEO-environmental Society
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• v.3 no.1
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• pp.67-77
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• 2002

Volume change of the dredged soils is composed of the volume loss of soil particle flowing over an outflow weir with water and settlement due to both the self-weight consolidation in reclaimed layer and the desiccation at the surface of reclaimed layer. In order to estimate the amount of soil particles flowing over an outflow weir with water, the evaluation procedure of loss ratio of the dredged soils is proposed in the present study based on the Marsal's modified breakage theory and the results of hydrometer analyses. To verify a validity of the proposed procedure, evaluated loss ratio is compared with results from the other existing methods. The model test results and those of field test were compared and analyzed. Also, the variation of soil loss ratio was examined through the model test in the lab.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.1
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• pp.13-21
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• 2008

Water losses in irrigation canals are mainly estimated as the sum of conveyance and delivery water loss. The losses occur via the evaporation, infiltration, gate operation and water distribution processing. Recently, the study regarding these water losses are not satisfactory enough, also delivery water loss has not been mainly considered on field design. The objective of this study is to investigate and analyze the volume of water loss in irrigation canals considering condition of actual farm land. A field measurement was performed at four research sites, which are managed by Korea Rural Community & Agriculture Corporation, to evaluate conveyance and delivery water loss for 2 years. The measurement was performed by canal type, size and designed flow using the inflow-outflow method at a major points such as start and end of each canal, derivation point of canal and inlet of paddy fields. Results of this study showed that water loss ratio in lateral canals was bigger than that of main canal unlike current design standard and the loss decrease as flow increase. The total of water loss ratio including conveyance and delivery water loss in several irrigation canals ranged between 33.25 and 45.0%.

• Journal of the Korean Applied Science and Technology
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• v.11 no.2
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• pp.139-146
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• 1994

MDABM and MDAEW, as a accelerating weight loss agents, were prepared by adding water to myristyldimethylbenzylammonium bromide(MDAB) and myristyldimethylethylammonium ethyl sulfate (MDAE) synthesized. As a result of weight loss finishing of the MDABW and MDAEW with NaOH on PET fiber, the ratio of weight loss of MDABW was very larger than that of MDAEW. This result showed that quaternary ammonium bromide had higher weight loss effect than quaternary ammonium sulfate, and the ratio of weight loss was greatly varied with the kind of quaternary ammonium salts used. In these conditions, proper treatment concentration, treatment time, and treatment bath ratio were about 8g/l, $6O{\sim}90min$, and $40:1{\sim}50:1$, respectively.

• Journal of Korean Clinical Health Science
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• v.3 no.1
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• pp.276-289
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• 2015

Purpose. To efficiently manage hospitals, this study aims to analyze the general characteristics, common-type balance sheet, common-type profit and loss statement and financial ratio of a tertiary general hospital and use the results as basic data for future hospital development by comprehending causes for problems and analyzing hospital management. Methods. By using information about a tertiary general hospital, located in A Metropolitan City, provided through Alio (www.alio.go.kr), a public organization information provider, Health Insurance Review & Assessment Service, and Ministry of Health and Welfare, this study used data during 3 years(2011 to 2013) by analyzing the general characteristics, common-type balance sheet, common-type profit and loss statement, industrial mean ratio and financial ratio of hospitals. Results. This study came to the following conclusions through the general characteristics, common-type balance sheet, common-type profit and loss statement, industrial mean ratio, financial ratio, circular chart and ROI by analyzing the data from 2011 to 2013. Conclusions. Overall, A Tertiary General Hospital showed an increase in fixed cost due to the construction of J Hospital and even in the size of capital and assets. It also showed an increase in medical profit, but the increase of its medical cost was higher, resulting in a financial loss. Especially, this hospital showed a slight decrease in net profit, featuring a reduction in inventory turnover. When the management of A Tertiary General Hospital was predicted based on such features, this hospital is expected to improve its profit structure through the opening of J Hospital, and it is necessary for this hospital to increase and sustain the turnover rate of inventories accumulated by managing them better.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.4
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• pp.855-869
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• 1997

In this paper, we proposed two kids of dynamic priority control mechanisms controlling the cell service ratio in order to improve the QOS(Quality of Service). We also analyse theoretically the characteristics of cell loss probability and mean cell delay time by applying the proposed priority control mechanisms to ATM switch with output buffer. The proposed priority control mechanisms have the same principles of storing cells into buffer but the different principles of serving cells from buffer. The one is the control mechanism controlling the cell service ratio according to the relative cell occupancy ratio of buffer, the other is the control mechanism controlling the cell service ratio according to both the relative cell occupancy ratio of buffer and the average arrival rate. The two service classes of our concern are the delay sensitive class and the loss sensitive class. The analytical results show that the proposed control mechanisms are able to improve the QOS, the characteristics of cell loss probability and mean cell delay time, by selecting properly the relative cell occupancy ratio of buffer and the average arrival rate. conventional DLB algorithm does not support synchronous cells, but the proposed algorithm gives higher priority to synchronous cells. To reduce synchronous cell loss rate, the synchronous cell detector is used in the proposed algorithm. Synchronous cell detector detects synchronous cells, and passes them cells to the 2nd Leaky-Bucket. So it is similar to give higher priority to synchronous cells. In this paper, the proposed algorithm used audio/video traffic modeled by On/Off and Two-state MMPP, and simulated by SLAM II package. As simulation results, the proposed algorithm gets lower synchronous cell loss rate than the conventional DLB algorithms. The improved DLB algorithm for multimedia synchronization can be extended to any other cells which require higher priority.