• Journal of the Society of Naval Architects of Korea
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• v.54 no.6
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• pp.515-521
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• 2017

Large Cavitation Tunnel (LCT) of KRISO enables us to conduct cavitation tests of the propeller attached to a ship model. As the ship model tests are done at rather high Reynolds number of 107~108, flow measurement system such as pitot tube cannot be employed because of structural safety problems in its system and difficulties in installing it within the test section. Thus, KRISO has developed new 3-D LDV system used in large test section of LCT. There are several difficulties in using 3-D LDV, which did not allow efficient operation of it. The first trouble was the calibration using the conventional pin hole. To make the focus with same laser-beam waists at the wanted position, the high spatial resolution CCD is utilized in the calibration procedure for 3-D LDV. The off-axis configuration provides two velocity components in the horizontal plane and on-axis configuration gives third velocity component in the vertical plane. The horizontal velocity components are also obtained in the coincidence mode, which prevents any misleading results in the off-axis configuration. The nominal wake of Aframax tanker model is measured by the developed 3-D LDV system. The measured hull wake showed good agreement with that obtained by CFD calculation.

• Journal of Veterinary Clinics
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• v.28 no.1
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• pp.63-70
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• 2011

To consider the iliac fossa as the vascular anastomosis site of kidney transplantation for the short-term study of acute rejection in pigs. Twelve domestic pigs weighing 39~48 kg underwent heterotopic renal allgraft transplantation. The experimental animals were divided into 2 groups in terms of renal vascular anastomosis site; the external iliac artery and vein were used in iliac fossa model (n = 6), the abdominal aorta and the caudal vena cava inferior to the kidney were used in abdominal cavity model (n = 6). Renal function was evaluated by daily measurement of plasma creatinine and BUN concentrations. The experiments' health including postoperative complications was also assessed daily for 8 days after transplantation. After euthanazation gross and histopathologic analysis was performed. All six pigs in iliac fossa model developed neuropraxia and lameness of the ipsilateral pelvic limb. However, no necrosis was observed in any pigs. In the abdominal cavity model, durations of both the surgical operation and the vascular anastomosis were significantly longer than those in the iliac fossa model. Furthermore, ischemia injury of the transplanted kidney was increased in abdominal cavity model, which induced accelerated-acute immune response from day 4 after transplantation. Despite of pelvic limb complication, the iliac fossa model showed more advantages including not only less ischemia time related to easy vascular anastomosis, but also less immune response during the acute rejection period. The results indicate that the iliac fossa model may be appropriate to the study of acute rejection in porcine kidney transplantation.

• The Journal of the Acoustical Society of Korea
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• v.39 no.2
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• pp.105-112
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• 2020

An analysis model of noise map is proposed to evaluate and reduce the acoustical noise of power plant and its surroundings. The sound powers of many noise sources are estimated by measuring the sound levels of major equipments in the power plant. The analysis of noise has been made by using ENPro that is a commercial program for environmental noise prediction. The proposed model is verified by comparing the results from noise analysis and measurement at several points of the power plant units 1 through 4, and residential areas. It is shown that noise map simulation using the proposed model has a reliability, since the overall noise level approximates within the error of ±2 dB. Furthermore, through noise analysis, the increasing effect of noise due to newly established units 5 and 6 on residential areas is also analyzed. Consequently, the noise barrier is designed to meet an environmental noise standard and satisfy low cost and safety conditions.

• Korean Parent-Child Health Journal
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• v.6 no.1
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• pp.31-45
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• 2003

This study is designed to produce basic data on the nursing intervention between infants and mothers after discharge from hospitals. This research is carried by investigating the nursing intervention during their after-delivery staying in the hospitals located in Pusan. The object of this study includes the neonatal wards of 51 hospitals. Data collection was carried from the 3rd of September, 2001 to the 4th of October in the same year. Tools for measurement using in this research is the nursing checklist designed by these researchers. The data were analyzed by using SPSS and the output was produced in frequency and percentage considering general characteristics and nursing activities. On the course of investigation, it was revealed that the average number of items checked are as follows; total beds in one hospital came up to 360.1, the beds in each newborn infant ward came up to 36.1, in each ward the numbers of incubators came up to 9.2 and intensive care unit to 1.7. In each ward 8.4 nurses and 2.9 nurse aids were working at that time. In each hospital, secure of air way, physical examination, eye care, umbilical cord care, maintenance of body temperature, identification of infant, nutritive condition, safety and danger management, infection management, mother-infantile interaction, medical assistant to doctor, medication and discharge education were comparatively well done. But, in case of emotional, social and cognitive aspect of nursing activities through interactions between newborn infants and nurses as substitutes are not reached to the adequate level. In the end, this study hereby suggests that further investigation on the device to facilitate the interaction between newborn infant and nurse as a nursing intervention of high quality.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.399-402
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• 2006

The purpose of this study is to propose a method for protecting injector face for prolonged combustion time and heat flux measurement technique at the injector face. To obtain basic design data and verify the performance of the proposed method, a regenerative cooling injector face was designed and manufactured for the hot firing test. Due to the safety reason, hot fire test were performed 3, 10, 30, 60 and 120 seconds time step. The discrepancy between analytical results adapting to combustion and nozzle and experimental results is believed due to the over estimation of the convection heat transfer calculation. for the injector face, flow velocity is almost negligible, therefore radiation is more important than convection. Consecutive hot firing test during 10, 30, 60 and 120 seconds combustion time shows good repeatability.

• Corrosion Science and Technology
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• v.14 no.1
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• pp.1-11
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• 2015

Local wall thinning and integrity degradation caused by several mechanisms, such as flow accelerated corrosion (FAC), cavitation, flashing and/or liquid drop impingements, are a main concern in carbon steel piping systems of nuclear power plant in terms of safety and operability. Thinned pipe management program (TPMP) had been developed and optimized to reduce the possibility of unplanned shutdown and/or power reduction due to pipe failure caused by wall thinning in the secondary side piping system. This program also consists of several technical elements such as prediction of wear rate for each component, prioritization of components for inspection, thickness measurement, calculation of actual wear and wear rate for each component. Decision making is associated with replacement or continuous service for thinned pipe components. Establishment of long-term strategy based on diagnosis of plant condition regarding overall wall thinning is also essential part of the program. Prediction models of wall thinning caused by FAC had been established for 24 operating nuclear plants. Long term strategies to manage the thinned pipe component were prepared and applied to each unit, which was reflecting plant specific design, operation, and inspection history, so that the structural integrity of piping system can be maintained. An alternative integrity assessment criterion and a computer program for thinned piping items were developed for the first time in the world, which was directly applicable to the secondary piping system of nuclear power plant. The thinned pipe management program is applied to all domestic nuclear power plants as a standard procedure form so that it contributes to preventing an accident caused by FAC.

• Progress in Medical Physics
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• v.30 no.4
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• pp.75-88
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• 2019

Diagnostic reference level (DRL) is employed to optimize the radiation doses of patients. The objective of this study is to review the DRLs for interventional procedures in Korea and abroad. Literature review was performed to investigate radiation dose index and measurement methodology commonly used in DRL determination. Dose area product (DAP) and fluoroscopy time within each major procedure category were systematically abstracted and analyzed. A wide variation was found in the radiation dose. The DAP values and fluoroscopy times ranged 0.01-3,081 Gy·㎠ and 2-16,878 seconds for all the interventional procedures, 8.5-1,679 Gy·㎠ and 32-5,775 seconds for the transcatheter arterial chemoembolization (TACE), and 0.1-686 Gy·㎠ and 16-6,636 seconds for the transfemoral cerebral angiography (TFCA), respectively. The DRL values of the DAP and fluoroscopy time were 238 Gy·㎠ and 1,224 seconds for the TACE and 189 Gy·㎠ and 686 seconds for the TFCA, respectively. Generally, the DRLs of Korea were lower than those of other developed countries, except for the percutaneous transluminal angioplasty with stent in arteries of the lower extremity (LE PTA and stent), aneurysm coil embolization, and Hickman insertion procedures. The wide variation in the radiation doses of the different procedures suggests that more attention must be paid to reduce unnecessary radiation exposure from medical imaging. Furthermore, periodic nationwide survey of medical radiation exposures is necessary to optimize the patient dose for radiation protection, which will ultimately contribute to patient dose reduction and radiological safety.

• Journal of Environmental Science International
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• v.18 no.3
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• pp.309-314
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• 2009

A accurate reservoir inflow is very important as providing information for decision making about the water balance and the flood control, as well as for dam safety. The methods to calculate the inflow were divided by the directed method to measure streamflow from upstream reservoirs and the indirected method to estimate using the correlation of reservoir water level and release. Currently, the inflow of multi-purpose dam is being calculated by the indirect method and the reservoir water level to calculate the storage capacity is being used by centimeters(cm) units. Corresponding to the storage volume of 1cm according to scale and water level of multi-purpose dam comes up to from several 10 thousand tons to several million tons. If it converts to inflow during 1 hour, and it comes to several hundred $m^3/sec$(CMS). Therefore, the inflow calculated on the hourly is largely deviated along the water level changes and is occurred minus value as the case. In this research, the water level gage has been developed so that it can measure a accurate water level for the improvement for the error and derivation of inflow, even though there might be various hydrology and meteorologic considerations to analyse the water balance of reservoir. Also, it is confirmed that the error and the standard derivation of data observed by the new gage is decreased by 89,6% and 1/3 & 87% and 2/3 compared to that observed by the existing gage of Daecheong and Juam multi-purpose dam.

• Journal of Ocean Engineering and Technology
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• v.24 no.6
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• pp.71-75
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• 2010

Although Graphite Compacted Vermicular (GCV) was first observed in 1948, the narrow range for stable foundry production precluded the high volume application of GCV to complex components such as cylinder blocks and heads until advanced process control technologies became available. This, in turn, had to await the advent of modern measurement electronics and computer processors. Following the development of foundry techniques and manufacturing solutions, primarily initiated in Europe during the 1990s, the first series production of GCV cylinder blocks began during 1999. Today, more than 40,000 GCV cylinder blocks are produced each month for OEMs, including Audi, DAF, Ford, Hundai, MAN, Mercedes, PSA, Volkswagen, and Volvo. Given that new engine programs are typically intended to support three to four vehicle generations, the chosen engine materials must satisfy current design criteria and also provide the potential for future performance upgrades without changing the overall block architecture. With at least a 75% increase in the ultimate tensile strength, a 40% increase in the elastic modulus, and approximately double the fatigue strength of either iron or aluminum, GCV is ideally suited to meet current and future of engine design and performance requirements.

• KIEAE Journal
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• v.7 no.4
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• pp.147-152
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• 2007

Numerous non-destructive tests(NDT) to assess the safety of real structures have been developed. System identification(SI) techniques using dynamic responses and behaviors of structural systems become an outstanding issue of researchers. However the conventional SI techniques are identified to be non-practical to the complex and tall buildings, due to limitation of the availability of an accurate data that is magnitude or location of external loads. In most SI approaches, the information on input loading and output responses must be known. In many cases, measuring the input information may take most of the resources, and it is very difficult to accurately measure the input information during actual vibrations of practical importance, e.g., earthquakes, winds, micro seismic tremors, and mechanical vibration. However, the desirability and application potential of SI to real structures could be highly improved if an algorithm is available that can estimate structural parameters based on the response data alone without the input information. Thus a technique to estimate structural properties of building without input measurement data and using limited response is essential in structural health monitoring. In this study, shaking table tests on three-story plane frame steel structures were performed. Out-put only model analysis on the measured data was performed, and the dynamic properties were inverse analyzed using least square method in time domain. In results damage detection was performed in each member level, which was performed at story level in conventional SI techniques of frequency domain.