• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1995.06a
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• pp.598-601
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• 1995

• Journal of Korean Society of Transportation
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• v.27 no.1
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• pp.7-16
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• 2009

Korea Highway Capacity Manual (2001) proposes only LOS(Level of Service) analysis method on non-control and two-way-stop intersections, not dealing with the analysis method on LOS for roundabouts, nor even including the term 'roundabout'. This study selects proper MOEs for roundabouts and criteria the LOS through simulation analysis. To attain this goal, the authors reviewed the methods to select proper MOEs in the first step, criteria the Los. For this study, the MOEs were chosen from existing literature, and used for the criteria. The MOEs to be applied to roundabouts in this research were entry traffic volume, v/c (volume/capacity) ratio, and average vehicle delays. The results showed that the maximum entry traffic volume(LOS F) at local one-lane roundabout was analyzed to be 1,700pcph and average vehicle delay 18 seconds LOS A was analyzed as 700pcph and average vehicle delay 3 seconds and v/c 0.41 in this case Maximum entry traffic volume(LOS F) at local area 2 lane roundabouts was analyzed as 2,900pcph and their average vehicle delay as 31 seconds LOS A was analyzed to be 1.500pcph and average vehicle delay 8 seconds, v/c 0.52.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.2
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• pp.55-61
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• 2010

Using 3D point data implemented from terrestrial LiDAR, this research has modelled geospatial data in 2 categories(gridded & un-gridded) and conducted LOS analysis experiment using outcome from the modeling exercise. To compare LOS analysis results from each of the 2 models in the above, maximum LOS (line of sight) range in the experimental area was specified as 30m in Area A, 40m in Area B and 50m in Area C and the time taken by LOS analysis and the number of visible points were measured. As for the LOS analysis experiment results, in comparison with the gridded model, the un-gridded model took about 3.9 times more time in Area A, 5.4 times in Area B and 6.5 times in Area C. In addition, about 0.97 times fewer points were measured in Area A, 0.93 times in Area B and 0.94 times in Area C. The difference between gridded model and un-gridded model in terms of the time taken by LOS analysis increased, as the maximum LOS range extended. On the other hand, the number visible points did not vary significantly in reference to the size of visible range.

• Structural Engineering and Mechanics
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• v.17 no.3_4
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• pp.393-408
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• 2004

There exists a clear need to monitor the performance of civil structures over their operational lives. Current commercial monitoring systems suffer from various technological and economic limitations that prevent their widespread adoption. The wires used to route measurements from system sensors to the centralized data server represent one of the greatest limitations since they are physically vulnerable and expensive from an installation and maintenance standpoint. In lieu of cables, the introduction of low-cost wireless communications is proposed. The result is the design of a prototype wireless sensing unit that can serve as the fundamental building block of wireless modular monitoring systems (WiMMS). An additional feature of the wireless sensing unit is the incorporation of computational power in the form of state-of-art microcontrollers. The prototype unit is validated with a series of laboratory and field tests. The Alamosa Canyon Bridge is employed to serve as a full-scale benchmark structure to validate the performance of the wireless sensing unit in the field. A traditional cable-based monitoring system is installed in parallel with the wireless sensing units for performance comparison.

• Quality Improvement in Health Care
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• v.17 no.1
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• pp.69-78
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• 2011

Objectives : The purpose of this study was to determine whether the published AMI report card could reduce in-patient mortality, 7-day after discharge mortality, and length of stay (LOS). Methods : Interrupted time-series intervention analysis was used to evaluate the impact of the report card for AMI care quality in November 2005 in terms of risk-adjusted in-patient mortality, risk-adjusted 7-day after discharge mortality, and DRGs case-mix LOS using the claim data of Health Insurance Review and Assessment Service. Results : Public disclosure of AMI care quality decreased risk-adjusted in-patient mortality and DRGs case-mix LOS by 0.00050% per month and 0.042 days per month respectively, however there was no effect on risk-adjusted 7-day after discharge mortality. Patterns of effect of public disclosure on AMI outcomes were a fluctuating pattern on risk-adjusted mortalities and a pulse impact for 1 month on DRGs case-mix LOS. Conclusions : We found the public disclosure of AMI care quality had decreasing effects on risk-adjusted in-patient mortality and DRGs case-mix LOS, but the size of the effect was marginal.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.10
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• pp.951-959
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• 2011

In this study, an OTM(on-the-move) antenna which is mounted on ground vehicles and is used for mobile communication between vehicle and satellite while moving was addressed. Since LOS(line-of-sight) of antenna should direct satellite consistently while vehicle moving to guarantee high satellite communication quality, active antenna LOS stabilization is a core technology for OTM antenna. Stabilization of a satellite tracking antenna which consists of 2-DOF gimbals, an elevation gimbal over an azimuth gimbal, was considered in this study. In consideration of driving mechanism which consists of gear train and flexible driving shafts, a two-mass-system dynamic model coupled with vehicle motion was presented. An internal PI-control loop + outer PI-control loop structure has been suggested in order to damp the torsional vibration and stabilize control system. The classical pole-placement method was applied to design control gains. In addition, a vehicle motion compensation control beside of the feedback control loop has been suggested to improve LOS stabilization performances. The feasibility of the proposed control design was verified along with some experimental results.

• Transactions on Electrical and Electronic Materials
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• v.11 no.2
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• pp.54-60
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• 2010

Polymer-assisted deposition is a chemical solution route to high quality thin films. In this process, the polymer controls the viscosity and binds metal ions, resulting in a homogeneous distribution of metal precursors in the solution and the formation of crack-free and uniform films after thermal treatment. We review our recent effort to epitaxially grow metal-nitride thin films, such as hexagonal GaN, cubic TiN, AlN, NbN, and VN, mixed-nitride $Ti_{1-x}Al_xN$, ternary nitrides tetragonal $SrTiN_2$, $BaZrN_2$, and $BaHfN_2$, hexagonal $FeMoN_2$, and nanocomposite TiN-$BaZrN_2$.

• Smart Structures and Systems
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• v.5 no.4
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• pp.457-468
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• 2009

A novel approach for integrating active sensing data interrogation algorithms for structural health monitoring (SHM) applications is presented. These algorithms cover Lamb wave propagation, impedance methods, and sensor diagnostics. Contrary to most active-sensing SHM techniques, which utilize only a single signal processing method for damage identification, a suite of signal processing algorithms are employed and grouped into one package to improve the damage detection capability. A MATLAB-based user interface, referred to as HOPS, was created, which allows the analyst to configure the data acquisition system and display the results from each damage identification algorithm for side-by-side comparison. By grouping a suite of algorithms into one package, this study contributes to and enhances the visibility and interpretation of the active-sensing methods related to damage identification. This paper will discuss the detailed descriptions of the damage identification techniques employed in this software and outline future issues to realize the full potential of this software.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.2426-2441
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• 2008

This research is analyzed by the operation frequency of Regional Railroad and the Load Factor on the level of each service based on the Regional railroad ticket sales data on the 2007 fiscal year. Because the Regional Railroad passenger's satisfaction is sensitive of the transportation demand alteration, this research analyzed LOS. In addition to, analyzed the LOS will affect driving patterns of the Regional Railroad.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.3
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• pp.305-317
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• 2015

The function failure of present major facilities is likely to lead to failure of related systems and/or whole facilities, increasing the necessity for protection of infrastructures, main structures, and major industrial facilities. In addition, safe and efficient management for urban infrastructure (waterworks and sewerage facilities, electricity, telecommunications, roads, etc) installed in the basement or on large cities grounds at various public areas is required. Recently in response to this demand, efforts for vitalizing asset management are being made such as enacting related laws and developing asset management system in the U.S., Australia, Europe and other advanced countries with the concept for a new maintenance. In our county, identifying maintenance system problems such as aging and rapid increasing of existing infrastructures and decision-making about updating maintenance is required for systematic and organizational maintenance. In this study, by comparing and observing the LOS(Level of Service) of each countries' waterworks and risk-based LOS, we suggest the direction of future urban water infrastructure management systems for more effective management.