• 대한디지털의료영상학회논문지
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• 제13권1호
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• pp.1-6
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• 2011

The purpose of our study was to determine the entrance surface dose and absorbed dose in ovary when using the metal speculum and plastic speculum in hysterosalpingography respectively. The examinations was performed in anthropomorphic phantom into which calibrated photoluminescence glass dosimeter were placed on symphysis pubis level surface and ovary area. We checked average fluoroscopy time and spot expose times during the hysterosalpingography. It was average fluoroscopy time 58 sec, spot expose 5 times. We divided the subjects into two different groups to used metal and plastic speculum. We measured 10 times of absorbed dose in the same condition of the anthropomorphic phantom. We compared two groups adsorbed dose on ovary with speculum material-related. The entrance surface dose on of plastic Speculum using group was average 17.23 mGy, absorbed dose on ovary was average 3.51 mGy. The entrance surface dose on ovary of metal Speculum using group was average 19.95 mGy, absorbed dose on ovary was average 4.14 mGy. Plastic speculum using group shows a decrease absorbed dose(17.9%) as compared with metal speculum using group. The method of plastic speculum using in hysterosalpingography. might provide us with lower radiation dose, especially in patients with childbearing stage.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1994년도 추계학술대회 논문집
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• pp.74-79
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• 1994

The log-log presentation of stress versus Larson-Miller parameter is obtained by uniaxial tensile test instead of the long time creep test. The used material for example calculations is SUS304 stainless steel. The temperature of the uniaxial tensile test can be determined by the Larson-Miller parameter of the design stress and the 0.1hr's rupture time of the uniaxial tensile test. The rupture time at the design temperature and stress can be determined by the Larson-Miller parameter of the stress. The average creep rate is the total deformation of the tensile test divided by the rupture time at the design stress and temperature. The liner trend and the order of the data of the average creep rate by this method is almost same as that of experimental results.

• Journal of information and communication convergence engineering
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• 제7권4호
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• pp.496-500
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• 2009

In EBCOT, the context modeling process takes excessive calculation time and this paper proposed a method to reduce this calculation time. That is, if the finest resolution coefficient is less than a pre-defined transfer factor the coefficient and its descendents skip the context modeling process. There is a trade-off relationship between the calculation time and the image quality or the amount of output data such that as this threshold value increases, the calculation time and the amount of output data decreases, but the image degradation increases. The experimental results showed that in this range the resulting reduction rate in calculation time was from 3% to 64% in average, the reduction rate in output data was from 32% to 73% in average.

• 한국산업보건학회지
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• 제33권1호
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• pp.3-5
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• 2023

Objective: This study introduces exposure concentrations of time-weighted average standard (TWA) evaluation and short-time exposure standard (STEL) evaluation for trichloroethylene in the cleaning process. Methods: Trichloroethylene measurement was conducted according to the KOSHA Guide (A-24-2019) method. It was carried out twice. Results: As a result of the first measurement, TWA concentration exceeded 4 times the exposure standard and STEL concentration exceeded 16 times, but the inaccuracy and breakthrough of the collection time could not be considered, so the second measurement was conducted. The second measurement result was lower than the first measurement result, but exceeded the exposure standards (TWA, STEL). Conclusions: We were able to confirm that the exposure level of workers in the cleaning process using trichloroethylene exceeded the exposure standard. And it is also considered necessary to grasp the approximate concentration using a detector tube in the preliminary survey.

• Child Health Nursing Research
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• 제14권1호
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• pp.5-13
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• 2008

Purpose: This study was done to describe utilization status of emergency medical service for children at one university affiliated hospital located in Seoul. Data were obtained from the medical records of patients under 13 years of age who visited the ER from January 1 to December 31, 2006. Method: Medical records missing the time of discharge were excluded in the analysis of waiting time, which resulted in 19,766 cases. Data were analyzed using SPSS WIN 14.0 version. Result: There were slightly more boys (58.4%), average age of the children was 3.97 years of age. More children at the aged 1 to 3 years (51.3%) visited the ER. Fever was the most frequent complaint: 5,180 cases (24.38%). The other complaints were head or facial laceration (10.55%), vomiting (9.63%), abdominal pain (8.06%), cough (7.67%), and painful limb swelling (6.34%). Average waiting time before the first medical examination was 17 minutes, and average ER stay time was 3 hours and 23 minutes. Conclusion: The results suggest the need to assign a nurse specialist for pediatric ER to provide more efficient care for the children. Also, extra staff assignment during the evening shift or extending office hours of local pediatricians should be considered.

• 한국도로학회논문집
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• 제15권5호
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• pp.135-144
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• 2013

PURPOSES : The purpose of this paper is to develop a methodology to estimate level of service of arterial including Exclusive Median Bus Lanes. METHODS : On 6 Exclusive Median Bus Lanes routes in Seoul, bus travel time and number of bus-stop per km were investigated. Also whether or not passing lane exists at bus-stop was checked. Based on the data from sites, bus travel time was estimated according to length of segment, number of bus-stop per km and whether or not passing lane exists at bus-stop. RESULTS : A bus travel time table was developed according to length of segment, number of bus-stop per km and whether or not passing lane exists at bus-stop. After bus travel speed and passenger car travel speed is estimated based on each travel time table and length of segment, two speeds are combined with weighted average speed using traffic volume of each lane group. Then weighted average speed is a measure of effectiveness of arterial including Exclusive Median Bus Lanes. CONCLUSIONS : It can be concluded that the proposed methodology can estimate level of service of arterial including Exclusive Median Bus Lanes considering the operation characteristics of Exclusive Median Bus Lanes.

• 한국멀티미디어학회논문지
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• 제24권9호
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• pp.1251-1260
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• 2021

This paper discusses missing data processing using simple moving average (SMA) and kalman filter. Also SMA and kalman predictive value are made a comparative study. Time series analysis is a generally method to deals with time series data in photovoltaic field. Photovoltaic system records data irregularly whenever the power value changes. Irregularly recorded data must be transferred into a consistent format to get accurate results. Missing data results from the process having same intervals. For the reason, it was imputed using SMA and kalman filter. The kalman filter has better performance to observed data than SMA. SMA graph is stepped line graph and kalman filter graph is a smoothing line graph. MAPE of SMA prediction is 0.00737%, MAPE of kalman prediction is 0.00078%. But time complexity of SMA is O(N) and time complexity of kalman filter is O(D²) about D-dimensional object. Accordingly we suggest that you pick the best way considering computational power.

• Geomechanics and Engineering
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• 제36권1호
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• pp.83-97
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• 2024

It is important to make reasonable prediction about the long-term deformation of high rockfill geostructures. However, the deformation is usually underestimated using the rockfill parameters obtained from laboratory tests due to different size effects, which make it necessary to identify parameters from in-situ monitoring data. This paper proposes a novel hybrid back-analysis method with a modified objective function defined for the time-dependent back-analysis problem. The method consists of two stages. In the first stage, an improved weighted average method is proposed to quickly narrow the search region; while in the second stage, an adaptive response surface method is proposed to iteratively search for the satisfactory solution, with a technique that can adaptively consider the translation, contraction or expansion of the exploration region. The accuracy and computational efficiency of the proposed hybrid back-analysis method is demonstrated by back-analyzing the long-term deformation of two high embankments constructed for airport runways, with the rockfills being modeled by a rheological model considering the influence of stress states on the creep behavior.

• Journal of information and communication convergence engineering
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• 제3권3호
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• pp.119-121
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• 2005

This paper aims to estimate the delay time of multiple signals in a multi-path environment. It also seeks to carry out a comparative analysis with the existing delay time under the proposed algorithm to develop a new algorithm that applies the space average method in a MUSIC algorithm. Unlike the existing delay time estimation algorithm, the developed algorithm was able to estimate the delay time in 5ns low. Therefore, the algorithm proposed in this paper improved the existing delay time estimated algorithm.

• Journal of Communications and Networks
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• 제15권5호
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• pp.469-475
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• 2013

In this paper, we propose an efficient interference management technique which controls the number of resource blocks (or subcarriers) shared with other cells based on statistical interference levels among cells. The proposed technique tries to maximize average throughput of a femto cell user under a constraint on non-real time control of a femto cell network while guaranteeing a target throughput value of a macro cell user. In our proposed scheme, femto cells opportunistically use resource blocks allocated to other cells if the required average user throughput is not attained with the primarily allocated resource blocks. The proposed method is similar to the underlay approach in cognitive radio systems, but resource block sharing among cells is statistically controlled. For the statistical control, a femto cell sever constructs a table storing average mutual interference among cells and periodically updates the table. This statistical approach fully satisfies the constraint of non-real time control for femto cell networks. Our simulation results show that the proposed scheme achieves higher average femto user throughput than conventional frequency reuse schemes for time varying number of users.