• Journal of computational fluids engineering
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• v.14 no.4
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• pp.31-40
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• 2009

Although optimization by sequentially refining metamodels is known to be computationally very efficient, the metamodel that can be used for this purpose is limited to Kriging method due to the difficulties related with sample points selections. The present study suggests a novel method for sequentially refining metamodels using Pareto Frontiers, which can be used independent of the type of metamodels. It is shown from the examples that the present method yields more accurate metamodels compared with full-factorial optimization and also guarantees global optimum irrespective of the initial conditions. Finally, in order to prove the generality of the present method, it is applied to a 2D transonic airfoil optimization problem, and the successful design results are obtained.

• Korean Journal of Radiology
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• v.23 no.6
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• pp.625-637
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• 2022

With regard to the indolent clinical characteristics of prostate cancer (PCa), the more selective detection of clinically significant PCa (CSC) has been emphasized in its diagnosis and management. Magnetic resonance imaging (MRI) has advanced technically, and recent international cooperation has provided a standardized imaging and reporting system for prostate MRI. Accordingly, prostate MRI has recently been investigated and utilized as a triage tool before biopsy to guide tissue sampling to increase the detection rate of CSC beyond the staging tool for patients in whom PCa was already confirmed on conventional systematic biopsy. Radiologists must understand the current paradigm shift for better PCa diagnosis and management. This article reviewed the recent literature, demonstrating the diagnostic value of pre-biopsy prostate MRI with targeted biopsy and discussed unsolved issues regarding the paradigm shift in the diagnosis of PCa.

• Korean Journal of Optics and Photonics
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• v.12 no.3
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• pp.158-164
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• 2001

We observed a velocity-selective saturated absorption spectrum when the pump beam intersects the probe beam at a finite angle with a saturated absorption spectroscopic configuration in the cesium vapor cell. And we also observed a dispersion-like signal by measuring the difference between two velocity-selective absorption spectra produced by two parallel probe beams intersected by one pump beam. The dispersion-like signal was changed with the crossing angle and the crossing position of the pump and probe beams and compared with the calculated result. The dispersion-like signal was used as a frequency discriminator, and the laser could be frequency-stabilized without any frequency modulation. As a result, the square root of Allan variance was $\sigma_y(\tau=1s)=7$\times10^{-12}$, for the sampling time of 1 s.of 1 s.

• Journal of Korean society of Dental Hygiene
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• v.10 no.5
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• pp.897-904
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• 2010

Objectives : The aim is to examine what a selective factor of dental institution in the elderly is, which can be used as a strategy for vitalizing hospital management, and which difference there is in selection of dental institution according to health-promotion lifestyle. Methods : Questionnaire survey of individual interview was carried out targeting 177 old people in over 65 years old of Jeonju, Iksan, and Gunsan in Jeollabuk-do Province by convenience sampling from August 16, 2010 to August 27. The analysis was performed by using SPSS WIN 12.0 program. Results : 1. The average mark of health-promotion lifestyle in the elderly was 2.69 points. The health responsibility was the highest with 2.91 points. 2. The mark of health-promotion lifestyle was higher in the higher educational level of the elderly(p<0.01), when monthly income is more than 2 million won(p<0.01), and in the better subjective awareness of oral condition(p<0.01). 3. The group with high mark of health-promotion lifestyle regarded reliability(p<0.001), economic efficiency(p<0.01), and facilities & cleanliness(p<0.01) as important factors when selecting dental institution. Conclusions : The development and expansion in health-promotion program targeting the elderly are seen to be necessary that reflect difference by sphere in health-promotion lifestyle. There will be necessity for pursuing even a strategy for the elderly in the group who have relatively low characteristic in the practice level of health-promotion lifestyle. Also, given understanding characteristics on the elderly and focusing on management proper for the needs of medical consumers, the successful medical management is thought to be likely possible.

• Atmosphere
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• v.32 no.4
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• pp.323-340
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• 2022

We analyzed the high-resolution wind data of Aircraft-Based Observation from the Mode-Selective Enhanced Surveillance (Mode-S EHS) data in Korea. For assessment of its quality, the Mode-S wind data was compared with the ECMWF ReAnalysis 5 (ERA5) reanalysis and Aircraft Meteorological Data Relay (AMDAR) data for more than 3-months from 7 May 2021 to 24 August 2021 near Incheon International Airport, Korea. Considering that the AMDAR reports are not provided by all commercial aircraft, total number of the Mode-S derived wind data with a second sampling rate was about twice larger than that of available AMDAR wind data. After the quality control procedures by removing erroneous samples, it was found that the root mean square errors (RMSEs) of the Mode-S retrieved winds are similar to that from the AMDAR winds. In particular, between 550 and 650 hPa levels, RMSE of the Mode-S (AMDAR) zonal wind against ERA5 data was about 2.3 m s^-1 (1.9 m s^-1), and those increased to 3.3 m s^-1 (2.4 m s^-1) in 200~500 hPa levels. A similar trend was found in the meridional wind, but a distinct positive mean bias of 2.16 m s^-1 was observed between 875 and 1,000 hPa levels. Winds retrieved from the Mode-S also showed a good agreement directly with AMDAR data. As the Mode-S provides a large amount of data with a reliable quality, it can be useful for both data assimilation in the numerical weather prediction model and situational awareness of wind and turbulence for aviation safety in Korea.

• Korean Journal of Clinical Laboratory Science
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• v.43 no.3
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• pp.105-112
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• 2011

More accurate evaluation of iodine consumption of Koreans can be made by measuring the urinary iodine excretion of people living in representative areas. The data about average iodine excretions by region, sex and age were gathered in order to suggest as a factor the criteria on the progress or prognosis of thyroid disease patients. This study was conducted on 3,000 subjects (2,000 Younggwang-gun residents and 1,000 Muan-gun residents) between July 2004 and August 2005. The data sampling was done based on stratified random sampling and the data were analyzed according to age (the subjects were divided into age groups, five years each) and sex of the subjects. Of the 3,000 subjects, a total of 1,592 people (1,174 in Younggwang-gun and 418 in Muan-gun) participated in this study, which used ISE (iodine ion selective electrode) to measure the concentration of iodine in urine. The 1,592 subjects are composed of 732 males and 860 females. The average urinary iodine excretion was $3.10{\pm}1.75mg/L$ (0.31~15.2 mg/L). The average iodine excretion of males was $3.09{\pm}1.61mg/L$ (0.42~15.2 mg/L) while it was $3.11{\pm}1.86mg/L$ (0.31~12.5 mg/L) among females, which represents no significant difference between males and females. However, the values were significantly higher than those of Europeans and Americans. There were statistically significant differences among the regions. When the data were analyzed according to age, females in their 40s were found to have a little less urinary iodine excretion and males had less and less iodine excretion as they get older. These results are deemed to have a statistically significant difference. This study was conducted on a large number of people (N=1,592) for the first time in Korea. If the data collected through this study can be regarded as the average urinary iodine excretion of Koreans, it is possible to conclude that the average iodine consumptions of Koreans are a lot more than Europeans and Americans. Thus, the effect of much iodine consumption should be studied further.

• Journal of the Korea Computer Graphics Society
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• v.28 no.3
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• pp.113-123
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• 2022

Ray tracing-based rendering creates by far more realistic images than the traditional rasterization-based rendering. However, it is still burdensome when implemented for a Head-Mounted Display (HMD) system that demands a wide field of view and a high display refresh rate. Furthermore, for presenting high-quality images on the HMD screen, a sufficient number of ray sampling should be carried out per pixel to alleviate visually annoying spatial and temporal aliases. In this paper, we extend the recent selective foveated ray tracing technique by Kim et al. [1], and propose an improved real-time rendering technique that realizes the rendering effect of the classic Whitted-style ray tracing on the HMD system. In particular, by combining the ray tracing hardware-based acceleration technique and time-constrained rendering scheme, we show that fast HMD ray tracing is possible that is well suited to human visual systems.

• Korean Journal of Adult Nursing
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• v.28 no.5
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• pp.514-524
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• 2016

Purpose: The purpose of this study was to describe the reported experiences of health management among twenty elderly workers living in urban areas. Methods: Corbin and Strauss's grounded theory approach was used to capture the meaning of health management. Theoretical sampling technique was used in the interviews. Using open coding, axial coding, and selective coding, data were collected and analyzed simultaneously. Results: The core category was 'pursuing health to take root in the workplace.' Four stages of the elderly workers' health management were identified as 'awareness of health changes', 'having the will to be healthy', 'utilization of health care resources', and 'reorganization of health habits.' However, when the elderly workers reported limited capacity to manage their health, then two new categories were described: 'awareness of health changes' and 'settlement with current health.' Conclusion: To the elderly workers the concept of working was equated with being healthy. Further, the participants reported having a future oriented view of health and sought health to extend their working lives. The specialized intervention of health management targeting elderly workers in the settlement stage of current health habits should be provided.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.2
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• pp.451-457
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• 1998

This paper describes a modelling method for SCR(selective catalystic reduction) system in refuse incineration plant. We consider the SCR system as a single input and single output system. For modelling the SCR system, an auto regressive exogeneous(ARX) modelling method is used. In this case, we should design the white noise input for modelling and put it on the system as an input$(NH_3)$, and take an outlet NOx as an output. From these two relations, we design the ARX model with 45 second delay time and transform to a discrete system with sampling time of 0.5 second. Using the obtained SCR model, we verify that the outlet NOx is deeply related with stoker`s moving in boiler of refuse incineration plant.

• Journal of Forest and Environmental Science
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• v.32 no.1
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• pp.10-19
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• 2016

This study was carried out in the Boin and Miryousef regions in Baneh of Kordestan province, west of Iran. Both areas were divided into two parts including protected and unprotected areas. In each area, 20 $1000-m^2$ circular plots were established following a selective method. Tree and shrub species were identified and the number of these species was counted in each sampling plot. The results indicated that 7 trees, 4 shrubs and 109 herbaceous species were found in the studied areas, 40 herbaceous, 7 tree and 3 shrub species were present in protected area, while unprotected area had 16 herbaceous and 3 tree species. The highest value of diversity indices belonged to protected areas in all vegetation layers. In tree layer, Quercus brantii had the greatest value of SIV, whereas the lowest value belonged to Pistacia atlantica. In shrub layer, the highest and lowest values of SIV belonged to Daphne mezereum and Cerasus microcarpa, respectively. Finally, in herbaceous layer, Luzula spicata had highest value of SIV, and lowest value was belonged to Galium sp.