• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1312-1316
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• 2009

Growing interest in $CO_2$ capturing from industrial processes and storage in underground formations is emerging from commitments in reducing $CO_2$ emissions manifested in the Kyoto Protocol. In this paper, $CO_2$ liquefaction system is treated in focus of liquefaction efficiency & production rate. Presently $CO_2$ is transported in ships or trucks at a pressure of 14-20 bar. Considering this, the liquefaction pressures of 20, 15, 6.5 bar are selected. Compressor work and cooling capacity are calculated and compared. In order to investigate the effect of intercooling, the compressed gas after compressor work is cooled by ambient air or seawater. In case of applying the intercooling to the system, consuming energy can be saved larger than 20%. In the lower liquefaction pressure, the more $CO_2$ can be obtained due to higher density. In the liquefaction pressure of 6.5 bar, its $CO_2$ production is about 35% higher than that of the system with the liquefaction pressure, 20 bar.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.5
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• pp.531-538
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• 2016

In this paper, we have proposed MIMO-IBFD system that can transmit and receive multiple data stream at the same time in the single band, and analyze the system. We have confirmed that MIMO-IBFD system requires multiple RF cancellation and multiple Digital cancellation techniques. In simulation, we have analyzed characteristic of received signal on MIMO-IBFD system, and evaluate system performance of conventional $2{\times}2$ MIMO system and MIMO-IBFD system. As simulation results, we have confirmed that MIMO-IBFD system can transmit and receive multiple data stream at the same time in the single band by using multiple RF and digital cancellation techniques. Additionally, we have confirmed that BER performance of $2{\times}2$ MIMO-IBFD system with low-level QAM modulation is similar to performance of $2{\times}2$ MIMO system, and BER performance of $2{\times}2$ MIMO-IBFD system with high-level QAM modulation is degraded in comparison with $2{\times}2$ MIMO system with high-level QAM modulation. We can confirm that MIMO-IBFD system requires high level self-interference cancellation technique in order to use high level modulation.

• Journal of Preventive Medicine and Public Health
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• v.53 no.6
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• pp.465-475
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• 2020

Objectives: This study was conducted to examine the association between birth patterns (defined in terms of birth order and interval) with delayed breastfeeding initiation in Indonesia. Methods: A cross-sectional study was carried out using data from the Indonesian Demographic and Health Survey 2017. The weighted number of respondents was 5693 women aged 15-49 years whose youngest living child was less than 2 years old. Multivariable logistic regression was conducted to evaluate associations between birth patterns and delayed breastfeeding initiation after adjusting for other covariates. Results: This study found that 40.2% of newborns in Indonesia did not receive timely breastfeeding initiation. Birth patterns were significantly associated with delayed breastfeeding initiation. Firstborn children had 77% higher odds of experiencing delayed breastfeeding initiation (adjusted odds ratio, 1.77; 95% confidence interval, 1.02 to 3.04; p<0.05) than children with a birth order of 4 or higher and a birth interval ≤ 2 years after adjusting for other variables. Conclusions: Firstborn children had higher odds of experiencing delayed breastfeeding initiation. Steps to provide a robust support system for mothers, especially first-time mothers, such as sufficient access to breastfeeding information, support from family and healthcare providers, and national policy enforcement, will be effective strategies to ensure better practices regarding breastfeeding initiation.

• Journal of Information Technology Services
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• v.17 no.1
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• pp.59-77
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• 2018

Software process (SP) authentication is a certification system designed in order to improve software process and ensure software reliability of the Korean small and medium enterprises (SMEs). It is composed of 3 grades, 17 evaluation items and 70 detailed evaluation items (software process). In order to certificate grade 2, 42 detailed evaluation items must be satisfied. In order to certificate grade 3, all 70 detailed evaluation items must be satisfied. SMEs are more vulnerable to manpower and material resources than the major company. Therefore, it is difficult for SMEs to invest in the long term to improve the software process. If we can provide the core evaluation items to SMEs, SMEs will be able to improve software quality more efficiently and effectively. It can be used as a short way to acquire SP authentication. The evaluation items of SP are defined as influencing each other. Therefore, the core evaluation items might be established using related techniques. Although we searched for previous researches and related informations, the associated study was insufficient. In this study, ANP (Analytic Network Process) technique was applied, and the core evaluation items of SP authentication were established. SMEs will be able to acquire SP authentication more easily using the core evaluation items. Finally, we expect that this study will be used as a basis material for creating the SP 2.0 version.

• Journal of Multimedia Information System
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• v.7 no.2
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• pp.97-106
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• 2020

The subjective experience would degrade the current artificial artistic aesthetic analysis. Since Qiong kiln ceramics have a long history and occupy a very important position in ceramic arts, we employed computer-aided technologies to quickly automatically accurately and quantitatively process a large number of Qiong kiln ceramic images and generate the detailed statistical data. Because the color features are simple and significant visual characteristics, the color features of Qiong kiln ceramics are analyzed for the quantitative aesthetics. The Qiong kiln ceramic images are segmented with GrabCut algorithm. Three moments (1st-order, 2nd-order, and 3rd-order) are calculated in two typical color spaces, namely RGB and HSV. The discrimination powers of the color features are analyzed according to various dynasties (Tang Dynasty, Five Dynasties, Song Dynasty) and various utensils (Pot, kettle, bowl), which are helpful to the selection of the discriminant color features among various dynasties and utensils. This paper is helpful to promoting the quantitative aesthetic research of Qiong kiln ceramics and is also conducive to the research on the aesthetics of other ceramics.

• Journal of Korean Society on Water Environment
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• v.18 no.4
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• pp.411-419
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• 2002

In this study, the series of ultrasonic irradiation for removal of refractory aromatic compounds has been selected as a model reaction in the batch reactor system in order to obtain the reaction kinetics. The products obtained from the ultrasonic irradiation were analysed by GC and GC/MSD. The decomposition of benzene produced toluene, phenol, and C1-C4 compounds, while the intermediates during the ultrasonic irradiation of 2,4-Dichlorophenol(DCP) were phenol, HCl, catechol, hydroquinone, and benzoquinone. It was found that more than 80% of benzene, and 2,4-DCP solutions were removed within 2 hours in all reaction conditions. The reaction order in the degradation of these three compounds was verified as pseudo-zero or first order. From the fore-mentioned results, it can be concluded that the refractory organic compounds could be removed by the ultrasonic irradiation with radicals, such as $H{\cdot}$ and $OH{\cdot}$ radical causing the high increase of pressure and temperature. Finally, it appeared that the technology using ultrasonic irradiation can be applied to the treatment of refractory compounds which are difficult to be decomposed by the conventional methods.

• The Korean Journal of Archival Studies
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• no.2
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• pp.169-193
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• 2000

This study aims to present a theoretical for domestic archival management studies and analyze curriculum through the established archival management course of nine universities. For this, the concrete study consists of the following : (1) to regulate concept of archival management studies, (2) to make suggestions which can be helpful to establish practical curriculum through especially analysis of curriculum in order to establish educational system suitable to domestic conditions. Data collection and analysis method in order to execute this study was mainly depended upon the documentary research and the major study method was to desirable curriculum of organizations in order to grasp distinctive feature of curriculum that is provided in this country at present. At this time, the curriculum of the object of analysis was limited to the curriculum of nine graduate schools, the organized subjects were divided into two sides of 'educational content side' and 'educational method side'. Based on such analysis, by grasping the whole inclination and problem points of subjects organized by domestic educational organizations, the suggestions was presented, considering at the present stage for developing education of archival management studies. Especially, the suggestions was presented here from two sides of 'the systematic side related to establishment of curriculum' and 'the content side of organizing subject'. It is expected that the suggestions presented after close analysis of the domestic present status would offer important information under the present conditions when the establishment of curriculum in the beginning stages.

• Advances in nano research
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• v.12 no.2
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• pp.167-183
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• 2022

In this paper, the free and forced vibration analysis of rotating cantilever nanoscale cylindrical beams and tubes is investigated under the external dynamic load to examine the nonlocal effect. A couple of nonlocal strain gradient theories with different beams and tubes theories, involving the Euler-Bernoulli, Timoshenko, Reddy beam theory along with the higher-order tube theory, are assumed to the mathematic model of governing equations employing the Hamilton principle in order to derive the nonlocal governing equations related to the local and accurate nonlocal boundary conditions. The two-dimensional functional graded material (2D-FGM), made by the axially functionally graded (AFG) in conjunction with the porosity distribution in the radial direction, is considered material modeling. Finally, the derived Partial Differential Equations (PDE) are solved via a couple of the generalized differential quadrature element methods (GDQEM) with the Newmark-beta techniques for the time-dependent results. It is indicated that the boundary conditions equations play a crucial task in responding to nonlocal effects for the cantilever structures.

• Journal of the Korean Chemical Society
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• v.31 no.5
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• pp.382-388
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• 1987

Kinetics studies on the reaction system of $[Ni(H_2O)_6]^{2+}+4CN^-{\rightleftharpoons}[Ni(CN)_4]^{2-}$ have been carried out in 0.005% gelatin solution at $25^{\circ}C$ by means of conductometry. The fifth-order kinetics were observed in the formation rate of $[Ni(CN)_4]^{2-}$ from the reaction of [Ni(H$_2O)_6]^{2+}$ and [CN]$^-$. The reaction was found first order in $[Ni(H_2O)_6]^{2+}$ and fourth order in [CN]$^-$. ${\Delta}H^{\neq}$ and ${\Delta}S^{\neq}$ were obtained the values of 5.15kcal/mole and -35.07 e.u., respectively. We have proposed the possible mechanism from the data obtained.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.1C
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• pp.28-36
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• 2011

As Power Line has been already installed over 60% of a residential area all over the world, Broadband Service has been possible using high-speed PLC(Power Line Communication) without new access line installed for Internet access. Because of such reason, PLC is researched as the most suitable service for Last Mile Solution. But, Power Line is designed for transmitting electric power, so peripheral Wireless Communication System is affected by a leak of electric wave. In this paper, we propose a High Performance Notch Filter algorithm in comparison with a existing notch filter for reduction of interference between existing Wireless Communication Service and Power Line Service. In addition, we implement the Notch Filter emulator appling a High Performance Notch Filter and using a embedded board.