• Ocean and Polar Research
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• v.32 no.1
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• pp.73-84
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• 2010

A terrestrial LiDAR was used to acquire precise and high-resolution topographical information of Malipo beach, Korea. Terrestrial LiDAR and RTK-DGPS (VRS) were mounted on top of a survey vehicle and used to scan 20 times stop-and-go method with 250 m spacing intervals at ebb tides. In total, 7 measurements were made periodically from 2008 to 2009 and after each beach replenishment event. We carried out GIS-based 3D spatial analysis such as slope and volume calculations in order to assess topographical changes over time. In relation to beach replenishment, comparative analysis of each volume change revealed them to be similar. This result indicates that the terrestrial LiDAR measurements are accurate and can be used to analyze temporal topographical changes. In conclusion, the methodology employed in this study can be used efficiently to exercise coastal management through monitoring and analyzing beach process such as erosion and deposition.

• Journal of Astronomy and Space Sciences
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• v.18 no.2
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• pp.129-136
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• 2001

The accuracy of GPS applications is heavily dependent on the satellite ephemeris and earth orientation parameter. Specially applications like as the real time monitoring of troposphere and ionosphere require real time or predicted ephemeris arid earth orientation parameter with very high quality. IGS is producing IGS ultra rapid product called IGU for real time applications which includes the information of ephemeris and earth orientation. IGU is being made available twice everyday at 3:00 and 15:00 UTC arid covers 48 hours. The first 24 hours of it are based on actual GPS observations and the second 24 hours extrapolated. We will construct the processing strategy for yielding ultra rapid product and demonstrate the propriety through producing it using 48 hours data of 32 stations.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.5
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• pp.315-321
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• 2009

Remote water meter monitoring is essential in U-city applications, whoγe digital water meter is a key component. While there are several kinds of water meters, the way to use has sensors has the merit of better preciseness, but the drawback of more power consumption. In this paper, we suggest an advanced sensing algorithm to diminish the power consumption while keeping the quality of preciseness. Our approach is to use less precise hall sensor for detecting the start of water impeller rotation with lower power consumption. During the rotation, a high precision hall sensor is used to meter the amount of water consumption. Our algorithm is analyzed to get 2 times lower power consumption than the previous algorithm.

• Journal of Chest Surgery
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• v.33 no.1
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• pp.45-50
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• 2000

Background: The CarboMedics prosthetic heart valve was produced in an attempt to improve the existing valve designs and was especially concerned with easily the implantation and further reduction of turbulence. Precise positioning of the valve in situ was achieved by the abilityof the valve to rotate relative to the sewing ring. Improved monitoring is possible due to increased radiopacity and the dacron sewing ring is coated with carbon to reduce pannus overgrowth. The leaflets have an opening angle of 78 degrees that apparently allows a rapid synchronous closure The aim of this study was to analyze the clinical performance of the CarboMedics valve prostheses(45 mitral 13 aortic and 7 double aortic-mitral valve replacement) were implanted in 65 patients(mean age 48.75$\pm$9.74 years) Result: The operative mortality was 3.1%(2/65) causes of death were low cardiac output syndrome. Total follow up was 1831 patient-months and mean follow up was 29.06$\pm$10.97 months/patient. No structural failure hemorrhage valve thrombosis and late death have been observed. Embolism occurred at a rate of 0.65%/Patient-year. Actuarial survival and thrombo-mbolism free rate at 36 months were 96.9% and 98.4% respectively. Consclusions: The CarboMedics valve stands for low valve related complicatons.

• Transactions of The Korea Fluid Power Systems Society
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• v.4 no.4
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• pp.1-7
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• 2007

Flow rate is one of the important variables for precise motion control and detection of the faults and fluid loss in many hydraulic components and systems. But in many cases, it is not easy to measure it directly. The orifice area of a servo valve by which the fluid flows is one of key factors to monitor the flow rate. In this paper, we have constructed an estimation algorithm for the effective orifice area by using the model of a servo valve cylinder control system and Kalman filter algorithm. Without geometry information about the servo valve, it is shown that the effective orifice area can be estimated by using only displacement and pressure data corrupted with noise. And the effect of the biased sensor data and system parameter errors on the estimation results are discussed. The paper reveals that sensor calibration is important in accurate estimation and plausible parameter data such as oil bulk modulus and actuator volume are acceptable for the estimation without any error. The estimation algorithm can be used as an useful tool for detecting leakage, monitoring malfunction and/or degradation of the system performance.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1049-1053
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• 1999

It is important to measuring and monitoring about state vectors of power system for precise operation control. All state vectors cannot be measured because it is economically disadvantageous, so that some state vectors are determined using state estimator. Determination of observability is a important precondition of power system state estimation because state estimation can be performed when given power system is observable. Recently as time-synchronization technique progress, using the PMU(Phasor Measurement Unit), state vector can be measured directly so that voltage phasor and current phasor measurements can be used for power system estimation. In this paper, observability algorithm is proposed to determinate the observability with real/reactive injection power measurements and real/reactive lineflow power measurements of existing measurement system and with phasor measurements of PMU. The jacobian matrix is newly composed for state estimation with measurements of added PMU, and state estimation is performed with least square estimatior. Comparison between state estimation result of existing measurement system and that of measurement system added PMU is presented.

• Journal of Environmental Impact Assessment
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• v.21 no.6
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• pp.893-901
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• 2012

Aircraft noise model such as FAA Integrated Noise Model(INM) has recently been used for forecasting the impact of noise in a residential area near an airport and quantifying the effect of various options for noise mitigation. The noise modeling should be reliable and precise in order to ensure the quality of the results provided. In this study, the validation of the noise levels simulated by the INM against measurement data recorded continuously at multiple monitoring sites was discussed. As a result of validation, the quality of the input data used as a fixed point profiles for the INM was enhanced. The noise contour maps were designed as a way to evaluate the aircraft noise of the vicinity of the airfield. The results of this study indicate that the validation of aircraft noise model by the measurement data would be required for the accurate assessment of the aircraft noise levels.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3399-3402
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• 2012

A liver fluke, Opisthorchis viverrrini (OV), is the major cause of the high incidence of cholangiocarcinoma in Thailand. The prevalence of OV infection remains high in various parts of the country, especially in Northeast Thailand and particularly in wetland rural areas where a large proportion of the community work in agriculture and continue the traditional practice of eating raw or uncooked cyprinoid fish products. The national control program seems to have had little impact in many of these areas, and it has been difficult to make precise assessments of the overall effectiveness of the program. This paper is the first report of prospective research project designed to monitor the impact of the national control program in rural communities located in a northeastern province and at high risk of OV infection. The participants in this initial survey were 1,569 villagers, aged 20-65 years, living in two subdistricts of Yasothon Province. Stool examinations showed that 38.68% were infected with OV. Males were slightly more likely to be infected than females, but the difference was not statistically significant. Infection was found to be positively associated with age in both males and females. The preliminary data indicate that the population selected for study is suitable for the purpose of the monitoring project.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.1
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• pp.130-134
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• 2015

The automobile industry is ubiquitous and involved in the handling of metal, machines, electricity, electron, and chemistry including the products of many types of processes. In the process of installing engines as a part of the car assembly line, the measurement and correction of the position of the stud bolts consumes a great deal of time. Additionally, defective parts must be manually removed. In the process of engine installation, the speed of the operation, related to the economics of vehicle assembly, is dependent upon measuring the precise position of the stud bolt, reducing the length of correction time, and increasing the working rate. This paper deals with securing the economic feasibility of the manufacturing process, increasing the safety by removing risk factors in the working area, and improving and equalizing the quality by developing an automatic system for the process involving a stud bolt.

• The Journal of Korea Robotics Society
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• v.9 no.2
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• pp.111-116
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• 2014

Human-robot co-operation becomes increasingly frequent due to the widespread use of service robots. However, during such co-operation, robots have a high chance of colliding with humans, which may result in serious injury. Thus, many solutions were proposed to ensure collision safety, and among them, collision detection algorithms are regarded as one of the most practical solutions. They allow a robot to quickly detect a collision so that the robot can perform a proper reaction to minimize the impact. However, conventional collision detection algorithms required the precise model of a robot, which is difficult to obtain and is subjected to change. Also, expensive sensors, such as torque sensors, are often required. In this study, we propose a novel collision detection algorithm which only requires motor encoders. It detects collisions by monitoring the high-pass filtered version of the velocity error. The proposed algorithm can be easily implemented to any robots, and its performance was verified through various tests.