• Nuclear Engineering and Technology
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• v.42 no.3
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• pp.297-304
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• 2010

In the design of advanced light water reactors (ALWRs) and in the safety assessment of currently operating nuclear power plants, it is necessary to evaluate the possibility of experiencing a degraded core accident and to develop innovative safety technologies in order to assure long-term debris cooling. The objective of this experimental study is to investigate the enhancement factors of dryout heat flux in debris beds by coolant injection from below. The experimental facility consists mainly of an induction heater, a double-wall quartz-tube test section containing a steel-particle bed and coolant injection and recovery condensing loop. A fairly uniform heating of the particle bed was achieved in the radial direction and the axial variation was within 20%. This paper reports the experimental data for 3.2 mm and 4.8 mm particle beds with a 300 mm bed height. The dryout heat density data were obtained for both the top-flooding and the forced coolant injection from below with an injection mass flux of up to $1.5\;kg/m^2s$. The dryout heat density increased as the rate of coolant injection increased. At a coolant injection mass flux of $1.0\;kg/m^2s$, the dryout heat density was ${\sim}6.5\;MW/m^3$ for the 4.8 mm particle bed and ${\sim}5.6\;MW/m^3$ for the 3.2 mm particle bed. The enhancement factors of the dryout heat density were 1.6-1.8.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.525-531
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• 2021

The importance and utilization of underground spatial is increasing due to urban concentration. And so underground spatial information is being built. Because underground spatial information is an important NSDI (National Spatial Data Infrastructure), the accuracy and performance of underground spatial exploration devices used for construction are managed separately. In accordance with the laws and regulations related to spatial information, the government is conducting performance tests for underground facilities surveying equipment. The current performance test site mainly targets metal pipelines, and there is no absolute position surveying inspection system. In this study, test bed model for performance inspection of underground space exploration equipment was presented. The test bed presented in this study can be used as a test site to supplement the limitations of the existing domestic test bed and to verify the performance of the latest equipment.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.4
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• pp.1-10
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• 2010

In this study, two estimation equations for preparing stream data for distributed storm runoff model were developed by analyzing the nonlinear relation between upstream flow-length and stream width, and between upstream flow-length and stream bed-slope. The equations for stream cell were tested in Chungjudam watershed (6,661 $km^2$) using KIMSTORM. Six storm events occurring between 2003 and 2008 were selected for the model calibration and verification before the test of equations. The average values of the Nash-Sutcliffe model efficiency (ME), the volume conservation index (VCI), the relative error of peak runoff rate (EQp), and the difference of time to peak runoff (DTp) were 0.929, 1.035, 0.037, and -0.406 hr for the calibrated four storm events and 0.956, 0.939, 0.055, and 0.729 hr for the two verified storm events respectively. The estimation equations were tested to the storm events, and compared the flood hydrograph. The test result showed that the estimation equation of stream width reduced the peak runoff and delaying the time to peak runoff, and the estimation equation of stream bed-slope showed the opposite results.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.197-200
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• 2011

This study aims to inform of current situation related to fire safety performance regulation on bed mattress in domestic and foreign countries, and even to make a slight analysis report on heat release rate of bed mattress based on preliminary KICT study which has comparison data together with several items inside house.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.2
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• pp.181-186
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• 2017

Synthetic aperture radar(SAR) has been widely used for reconnaissance. It provides high-resolution, day-and-night and weather-independent images for a multitude of applications. Because SAR coherently combines many viewing angles to effectively create a large aperture(narrow beam) radar, the test-bed should be capable of moving straightly SAR sensor for the integration angle to meet resolution. This paper describes the test-bed developed to test and evaluate the SAR performance. It forms high-quality images in real time and saves the raw data for the purpose of post processing on the ground.

• The Korean Nurse
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• v.36 no.2
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• pp.73-83
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• 1997

Bed rest is recommended to prevent postlumbar puncture headaches(PLPHA), but the period of bed rest varies in the literature from 6 hours to 24 hours. In clinical practice the period of bed rest varies but nursing methods for adults and children have little difference. In Seoul National University Hospital, children have been given at least 6 hours bed rest after a lumbar puncture. Pediatric oncology patients require a lumbar puncture for an initial diagnosis, follow up treatment or administration of chemotherapeutic agent. But it is difficult for young children to lie supine or to refrain from their usual activities in any way, and unpleasant problems related to a shortage of beds often occurs during discharge or in an outpatient setting. The purpose of this study is to substantiate the preventive effect of PLPHA by the period of bed rest, to identify the other factors that influence PLPHA, and to use the nursing methods proper to children. The subjects were 65 children, ages 1-17, undergoing treatment in the children's cancer center at SNUCH during the period June 1, 1995, to Aug. 31, 1995. The team nurses asked questions about PLPHA of the parents and children in order to fill out a questionnaire. The data were evaluated by percent, t-test, Chi-square test and Mann-Whitney U test. Result; 1. There was no significant difference relating the bed rest time spent to the occurrence of postspinal headaches (t-test). 2. There was a significant risk of PLPHA in the children who were irritable before procedure and/or had experienced previous PLPHA(p<0.05, ${x^2}-test$). 3. The following factors were not found to be associated with increased risk of PLPHA: previous puncture experience, giving analgesics, the choice of puncturist, inpatient/outpatient status, gauge of needle, purpose, the amount of CSF removed, gender, diagnosis, the number of peripheral WBCs, previous lumbago experience after LP, position after bed rest, age, the number of aural puncture at the time. A longer period of bed rest is unlikely to be more effective to prevent PLPHA and seems impractical. A shorter period will save time and effort. Perhaps it will also allay some of the fears which surround LP. So 1 hour bed rest after LP is suggested and nursing methods for emotional support should be investigated to reduce PLPH.

• Journal of the Korea Society of Computer and Information
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• v.8 no.3
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• pp.9-15
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• 2003

IEEE1394 standard supports both isochronous and asynchronous data transmission, thus enabling high-speed data exchange between PC and networked home electronic devices. This paper describes an implementation of Test Bed for Linux based IEEE1394 communication test. In this paper, An integrated Software was developed to test IEEE1394 communication environment. To develop the software, open source software(gscanbus,dvgrab, playdv, Xine, Kino) for the Linux environment was investigated and integrated. It was tested such as the communication among the devices, asynchronous date transmission, isochronous data transmission, and its result was successful. This integrated software has the potential to become efficient test tool for the futher development of networked home electronic devices and multimedia services.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.5
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• pp.835-842
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• 2020

This paper considers a method of reproducing abnormal and fault operation for smart monitoring of thrust bearing used in wave power generation system. In order to develop smart monitoring technology, abnormal and failure data of actual equipment are required. However, it is impossible to artificially break down the actual equipment in operation due to safety and cost. To tackle this problem, a test bed that can secure data through reproduction of a faulty operating environment should be developed. Therefore, in this study, test bed that can reproduce each situation was developed and the operation result was analysis after identifying the situation to be reproduced through the failure factor analysis of the thrust bearing.

• Journal of Positioning, Navigation, and Timing
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• v.13 no.1
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• pp.103-110
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• 2024

In this paper, a test bed for real-time network Real-Time Kinematic (RTK) research was constructed using reference stations of the NGII. A group of candidate station networks was derived, including three stations in Seoul. The group consisted of four stations with a distance of less than 100 km between them. Among several candidates, a network composed of stations with short distances between them and demonstrating good data quality for all reference stations was selected as the test bed. After collecting real-time data in Radio Technical Committee for Maritime services (RTCM) format from the selected stations and conducting a noise analysis on measurements, mm-level carrier phase measurement noise was confirmed. Afterwards, the user set the reference station inside the test bed and analyzed the network RTK positioning performance of the MAC method using the GPS L1 frequency as post-processing. From the result of the analysis it was confirmed that the residual error for all users was within 10 cm after applying the correction. Additionally, after determining integer ambiguities through Least-squares AMBiguity Decorrelation Adjustment (LAMBDA), it was confirmed that the fix rate was 100%, and all ambiguities were resolved as true values.

• Journal of Advanced Navigation Technology
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• v.10 no.4
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• pp.299-305
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• 2006

DURUMI-II is developed into test bed airplane for the multi-purpose flight test. It satisfied the civil aeronautics law. DURUMI-II is equipped with Airborne System for acquiring of flight test data and can fly by oneself. In this paper, the redundancy of DURUMI-II control system is operated sequentially is explained. The divided control surface and the requiring program method for flight test are described. Also, it is described that the exact control input is applied using the new method. Finally, the results of flight test for new method are analyzed.