• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.3
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• pp.307-311
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• 2003

The test did for the determine the optimized ratio of cation to anion in mixed ion exchange demineralizers. Binary, ternary, quaternary, and quinary cation and anion adsorption was performed to develop a comprehensive experimental data set from small-volume batch tests to obtain the selectivity coefficients of many cations and anions. The quantitative run time might be estimated by such ion exchange models as semi-empirical mass action and surface complexation models. The demineralizer can be used longer by increasing the ratios of cation to anion exchange resins in the bed.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.53.4-53.4
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• 2017

With large-volume surveys becoming the norm, it is increasingly important to accurately model the galaxy-halo connection and being able to create mock universes of galaxies - starting from dark matter halo catalogs - that reproduce with high-fidelity all the characteristics of a given experiment. This step is necessary, in order to safely interpret cosmological data and fully control systematic effects. We are developing a new Python-based tool which integrates several existing packages and allows one to reproduce many of the forms used to describe galaxy-halo models, ranging from halo occupation distribution (HOD) to abundance matching techniques, along with the characteristics of a given survey and the main testable observables. We are making the code parallel for high-performance parallel-architectures.

• The Journal of Asian Finance, Economics and Business
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• v.3 no.2
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• pp.33-39
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• 2016

This study empirically evaluates the impact of exchange rate volatility, foreign direct investment, terms of trade, inflation, and industrial production and foreign exchange reserves on Pakistani trade volume over the period of 1975-2010 using quarterly data set. The study employs financial econometrics methods such as Augmented Dickey Fuller (ADF) test GARCH (1, 1) technique and Almon Polynomial Distributed Lag (APDL) models to estimate the relationship of variables. Findings of the study are in accordance with theoretical relationships presented by Clark, Tamirisa, Wei, Sadikov, & Zeng (2004), McKenzie (1999), Dellas & Zilberfarb (1993) and Côté (1994). These findings are also in accordance with the empirical studies which support positive relationship of exchange rate volatility and exports presented by Hsu & Chiang (2011), Chit (2008), Feenstra & Kendall (1991), Esquivel & Larraín (2002) and Onafowora & Owoye (2008). Findings of the study in terms of imports are supported by the studies such as Lee (1999), Alam & Ahmad (2011) and Arize (1998). The study also recommends some very important policy prescriptions.

• Journal of Korea Multimedia Society
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• v.24 no.11
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• pp.1472-1480
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• 2021

Image stacking technique is one of the key techniques for complex surface reconstruction. The process includes sample collection, image processing, algorithm editing, surface reconstruction, and finally reaching reliable conclusions. Since this experiment is based on laser scanning confocal microscope to collect the original contour information of the sample, it is necessary to briefly introduce the relevant principle and operation method of laser scanning confocal microscope. After that, the original image is collected and processed, and the data is expanded by interpolation method. Meanwhile, several methods of surface reconstruction are listed. After comparing the advantages and disadvantages of each method, one-dimensional interpolation and volume rendering are finally used to reconstruct the 3D model. The experimental results show that the final 3d surface modeling is more consistent with the appearance information of the original samples. At the same time, the algorithm is simple and easy to understand, strong operability, and can meet the requirements of surface reconstruction of different types of samples.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.57.1-57.1
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• 2019

In support of current and upcoming large-volume cosmological surveys such as the SDSS-IV eBOSS, LSST, and DESI, we present an extensive suite of high-resolution cosmological hydrodynamical simulations spanning a large range of cosmological and astrophysical parameters. We follow the evolution of gas, dark matter, neutrinos, and dark radiation, and consider several combinations of box sizes and number of particles - enhancing the resolution up to $3{\times}33283=110$ billion particles in a (100 h-1 Mpc)3 box size. We also provide 100,000 skewers for a variety of redshift slices and combination of cosmological and astrophysical parameters, useful for interpreting upcoming high-quality $Lyman-{\alpha}$ forest data. These novel simulations represent an improvement over our previous runs, and can be useful for a broader variety of cosmological and astrophysical applications, ranging from the three-dimensional modeling of the $Lyman-{\alpha}$ forest to cross-correlations between different probes, for studying the expansion history of the Universe including massive neutrinos, and for particle-physics related topics.

• Journal of the Korean Society of Mechanical Technology
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• v.20 no.6
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• pp.872-878
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• 2018

Steam tables including superheated, saturated and compressed region were simultaneously modeled using the neural networks. Pressure and temperature were used as two inputs for superheated and compressed region. On the other hand Pressure and dryness fraction were two inputs for saturated region. The outputs were specific volume, specific enthalpy and specific entropy. The neural network model were compared with the linear interpolation model in terms of the percentage relative errors. The criterion of judgement was selected with the percentage relative error of 1%. In conclusion the neural networks showed better results than the interpolation method for all data of superheated and compressed region and specific volume of saturated region, but similar for specific enthalpy and entropy of saturated region.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3543-3548
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• 2023

Shutdown chemistry evolution is performed in nuclear power plants at each refueling outage (RFO) to establish safe conditions to open system and minimize inventory of corrosion products in the reactor coolant system (RCS). After hydrogen peroxide is added to RCS during shutdown chemistry evolution, corrosion products are released and are removed by filters and ion exchange resins in the chemical volume control system (CVCS). Shutdown chemistry evolution including RCS clean-up time to remove released corrosion products impacts the critical path schedule during RFOs. The estimation of clean-up time prior to RFO can provide more reliable actions for RCS clean-up operations and transients to operators during shutdown chemistry. Electric Power Research Institute (EPRI) shutdown calculator (SDC) enables to provide clean-up time by Co-58 peak activity through operational data from nuclear power plants (NPPs). In this study, we have investigated the results of EPRI SDC by shutdown chemistry data of Co-58 activity using NPP data from previous cycles and modeled the estimated clean-up time by EPRI SDC using average Co-58 activity of the NPP. We selected two RFO data from the NPP to evaluate EPRI SDC results using the purification time to reach to 1.3 mCi/cc of Co-58 after hydrogen peroxide addition. Comparing two RFO data, the similar purification time between actual and computed data by EPRI SDC, 0.92 and 1.74 h respectively, was observed with the deviation of 3.7-7.2%. As the modeling the estimated clean-up time, we calculated average Co-58 peak concentration for normal cycles after cycle 10 and applied two-sigma (2σ, 95.4%) for predicted Co-58 peak concentration as upper and lower values compared to the average data. For the verification of modeling, shutdown chemistry data for RFO 17 was used. Predicted RCS clean-up time with lower and upper values was between 21.05 and 27.58 h, and clean-up time for RFO 17 was 24.75 h, within the predicted time band. Therefore, our calculated modeling band was validated. This approach can be identified that the advantage of the modeling for clean-up time with SDC is that the primary prediction of shutdown chemistry plans can be performed more reliably during shutdown chemistry. This research can contribute to improving the efficiency and safety of shutdown chemistry evolution in nuclear power plants.

• Fashion & Textile Research Journal
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• v.17 no.6
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• pp.988-995
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• 2015

Gaps between the upper edges of brassiere mold cups and the breasts are one of the most serious issues in realizing comfort wearing of commercial brassieres for small-breasted women. The surplus ease amounts causing the fit problem were measured from 3D wearing images of the small-breasted women's brassieres. The effect after the removing the surplus ease amounts from the upper edge of mold cup was approved by subjective wearing evaluation. Since the volume distribution of mold cup can also affect the wearing sensation of brassiere, the subjective wearing sensation was compared for two brassieres of different volume distributions, V_L, of which volume was concentrated at the lower cup, and V_C, which has the thickest part at the nipple. As the results, the suitable sensation for cup volume and the natural wearing silhouette could be accomplished by removing the surplus ease amounts from the upper edge of mold cup to reduce the gaps between brassieres and the breasts, which could be accomplished through an approach reducing the volume near the upper edge of mold brassiere cup and making the volume concentrated at the lower cup. These works provide a useful information on the design of the brassiere mold cups for small-breasted women. Moreover, modeling methods of 3D scan data and 3D printing technique for making more accurate mold cases used in this research can be helpful to develop and evaluate clothing products in future.

• Journal of the Korean Institute of Gas
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• v.20 no.1
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• pp.13-22
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• 2016

This paper presents development of an appropriate procedure and flow chart to analyze shale gas production data obtained from a multi-fractured horizontal well according to flow characteristics in order to calculate an estimated ultimate recovery. Also, the technical considerations were proposed when a rate transient analysis was performed with field production data occurred to only $1^{st}$ transient flow. If production data show the $1^{st}$ transient flow from log-log and square root time plot analysis, production forecasting must be performed by applying different method as before and after of the end of $1^{st}$ linear flow. It is estimated by an area of stimulated reservoir volume which can be calculated from analysis results of micro-seismic data. If there are no bottomhole pressure data or micro-seismic data, an empirical decline curve method can be used to forecast production performance. If production period is relatively short, an accuracy of production data analysis could be improved by analyzing except the early production data, if it is necessary, after evaluating appropriation with near well data. Also, because over- or under-estimation for stimulated reservoir volume could take place according to analysis method or analyzer's own mind, it is necessary to recalculate it with fracture modeling, reservoir simulation and rate transient analysis, if it is necessary, after adequacy evaluation for fracture stage, injection volume of fracture fluid and productivity of producers.

• Korean Journal of Health Education and Promotion
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• v.29 no.1
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• pp.59-72
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• 2012

Objectives: This study aimed to estimate the trajectory of depressive symptoms among aged 20 years adults and examine the direct and indirect pathway linking socioeconomic status(education attainment, household income, occupation), alcohol use and depressive symptoms. It particularly focused on whether alcohol use would mediate the relationship between socioeconomic status and depressive symptoms. Methods: This study analysed 13,763 households of Korean Welfare Panel Study 1st, 2nd, 3rd data using Latent Growth Curve Modeling. Results: The results showed that study participants tend to decrease depressive symptoms with years. Similar to the findings of the previous studies, education attainment and household income among the socioeconomic status factors effected directly depressive symptoms and indirectly by mediating alcohol volume controlling sex and age. Conclusions: Based on findings of this study, the policy and practical implications were discussed.