• 한국식품과학회지
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• 제20권5호
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• pp.704-710
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• 1988

본 실험은 여러 가지 보습제 및 방부제(Sodium lactate, Glycerol, Propylene glycol, sorbitol, Mannitol, Sodium benzoate, Potassium sorbate 및 Calcium propionate)처리를 한 중간수분식품 모델의 보수력을 등온흡습 곡선으로 처리하였다. 중간수분식품의 모델은 오징어를 재료로 사용하였고, 제조된 모델식품의 저장성도 검토하였다. 저장요인으로서는 지질산패, 색깔변화 및 곰팡이 번식을 관찰하였다. 보습제의 보수력은 mannitol

• Nuclear Engineering and Technology
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• 제52권1호
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• pp.37-50
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• 2020

A passive containment cooling system (PCCS) has been developed as advanced safety feature for innovative power reactor (iPOWER). Passive systems are inherently less stable than active systems and the PCCS encountered the flashing-induced instability previously identified. The objective of this study is to develop stability maps for flashing-induced instability using MARS (Multi-dimensional Analysis of Reactor Safety) code. Firstly, we conducted a series of sensitivity analysis to see the effects of time step size, nodalization, and alternative MARS user options on the onset of flashing-induced instability. The riser nodalization strongly affects the prediction of flashing in a long riser of the PCCS, while time step size and alternative user options do not. Based on the sensitivity analysis, a standard input and an analysis methodology were set up to develop the stability maps of PCCS. We found out that the calculated equilibrium quality at the exit of the riser as a stability boundary above 5 kW/㎡ was approximately 1.2%, which was in good agreement with Furuya's results. However, in case of a very low heat flux condition, the onset of instability occurred at the lower equilibrium quality. In addition, it was confirmed that inlet throttling reduces the unstable region.

• 한국경영과학회지
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• 제21권1호
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• pp.51-69
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• 1996

We consider a consumer self-selection model in which a regulated firm faces two market segments with differing valuation of quality of telecommunication services and examine some economic implications from the behaviors of the firm. In the context of a regulated monopolist, even though the results depend on the degree of privatization, the firm could lower the quality of the low-end model and reduce the price of the high-end in order to alleviate cannibalization. This justifies the provision of universal service policy in the telecommunications market. Based on this self-selection model, we also analyze an extended model of product introduction and show that the monopolist will introduce new product with the same introduction time of social planner. However, when we consider competition among firms, the market equilibrium may not guarantee the efficient time of product introduction.

• 한국대기환경학회지
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• 제26권1호
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• pp.77-84
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• 2010

The diffusion and partition coefficients of polyurethane foam (PUF) are estimated using a microbalance experiment and small chamber test. The microbalance is used to measure sorption/desorption kinetics and equilibrium data. When the diffusion condition is controlled in the chamber of the sample, interactions between volatile organic compounds (VOCs) and PUF can lead to the estimation of a relatively homogenous rate of mass transfer in the interiors and surfaces of PUF. The estimates of the material/air partition coefficient (K) and the material-phase diffusion coefficient (D) are shown to be independent of the concentrations of VOCs. This approach, if applied to a diffusion-controlled or physically-based model, can facilitate more precise prediction of their source/sink behavior. Although further research and more rigorous validation is needed, an emission model applied with the diffusion and partition coefficients from this research holds promise for the improvement of reliability in predicting the behavior of VOCs emitted from porous building materials by D and K.

• Journal of Communications and Networks
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• 제9권3호
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• pp.319-329
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• 2007

This paper presents a price-based quality-of-service (QoS) control framework for two-class network services, in which circuit-switched and packet-switched services are defined as "premium service class" and "best-effort service class," respectively. Given the service model, a customer may decide to use the other class as a perfect or an imperfect substitute when he or she perceives the higher utility of the class. Given the framework, fixed-point problems are solved numerically to investigate how static pricing can be used to control the demand and the QoS of each class. The rationale behind this is as follows: For a network service provider to determine the optimal prices that maximize its total revenue, the interactions between the QoS-dependent demand and the demand-dependent QoS should be thoroughly analyzed. To test the robustness of the proposed model, simulations were performed with gradually increasing customer demands or network workloads. The simulation results show that even with substantial demands or workloads, self-adjustment mechanism of the model works and it is feasible to obtain fixed points in equilibrium. This paper also presents a numerical example of guaranteeing the QoS statistically in the short term-that is, through the implementation of pricing strategies.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 추계학술대회
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• pp.127-130
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• 2022

본 논문은 생성자 손실함수를 이용한 가창 음성합성 모델링에 대한 연구로서 기존 이미지 생성에 최적화된 딥러닝 알고리즘 중 BEGAN모델을 오디오 생성모델(SVS모델)에 적용시킬 때 발생할 수 있는 여러 요인에 대해 분석하고 최적의 품질을 도출하기 위한 실험을 수행하였다. 특히 BEGAN 기반 모델에서 제안된 L1 loss가 어느 시점에서 감마(𝛾)파라미터의 역할을 상실하게 한다는 점을 개선하고자 알파(𝛼)파라미터를 추가한 후 각 파라미터 값들의 구간별 실험을 통해 최적의 값을 찾아냄으로써 가창합성 생성물의 품질향상에 기여할 수 있음을 확인하였다.

• 한국환경과학회지
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• 제22권8호
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• pp.1009-1017
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• 2013

Perfluorooctanoic acid (PFOA) and perfluorooctyl sulfonate (PFOS) is a new persistent organic pollutants of substantial environmental concern. This study investigated the potential of magnetic ion exchange resin (MIEX$^{(R)}$) as the adsorbent for the removal of PFOA and PFOS from Nakdong River water. In our batch experiments, we studied the effect of some parameters (pH, temperature, sulfate concentration) on the removal of PFOA and PFOS. The results of sorption kinetics on MIEX$^{(R)}$ show that it takes 90 min to reach equilibrium but the economical contact time and dosage were 30 min and 10 mL/L. An increase in pH (pH 6~10) leads to a decrease in PFOA (2.0%) and PFOS (3.6%) sorption on MIEX$^{(R)}$. The sorption of both PFOA and PFOS decreases with an increase in ionic strength for sulfate ion (${SO_4}^{2-}$), due to the competition phenomenon. An increase in water temperature ($8^{\circ}C{\sim}28^{\circ}C$) in water leads to a increase in PFOA (2.8%) and PFOS (4.3%) sorption on MIEX$^{(R)}$. Based on the sorption behaviors and characteristics of the adsorbents and adsorbates, ion exchange and hydrophobic interaction were deduced to be involved in the sorption, and hemi-micelles possibly formed in the intraparticle pores.

• Asian-Australasian Journal of Animal Sciences
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• 제20권4호
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• pp.466-470
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• 2007

CCAAT/enhancer binding protein ${\alpha}$($C/EBP{\alpha}$) plays an important role in lipid deposition and adipocyte differentiation. In order to find genetic markers to improve the meat quality of Korean cattle, the bovine $C/EBP{\alpha}$ gene was chosen as a candidate gene to investigate its association with carcass and meat quality traits in Korean cattle. A single nucleotide polymorphism (SNP) was identified at position 271 (A/C substitution) of coding region in the $C/EBP{\alpha}$ gene. A PCR-RFLP procedure with restriction enzyme SmaI was developed for determining the marker genotypes. The frequencies of alleles C and A and were 0.374 and 0.626, respectively. The genotype frequencies for CC, AC and AA were 12.9, 49.0 and 38.1%, respectively, in Korean cattle population. The frequencies of genotype were in agreement with Hardy-Weinberg equilibrium. Association analysis indicated that the gene-specific SNP marker of $C/EBP{\alpha}$ showed a significant association with marbling score (p<0.05). The animals with AA genotype had higher marbling score than those with the AC or CC genotype. Although further studies are needed to validate our results, the $C/EBP{\alpha}$ gene could be useful as a genetic marker for carcass and meat quality traits in Korean cattle.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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• pp.20-36
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• 2001

The purpose of this paper is estimating environmental carving capacity of Seoul Metropolitan Area for a sustainable city management using system dynamics model. A sustainable development requires a society to define sustainability constraints or environmental limits, environmental carving capacity. Environmental carving capacity can be defined as the level of human activity which a region can sustain at an acceptable quality of life level. This concept of environmental carving capacity has several important application to sustainable city planning and management. If the limitation of a human activity can be supported by a scientific data on carving capacity, the resulting decision and actions could more easily win public support for a sustainable development. However, one of the key issues is how to operationalize the carving capacity. In this paper, the environmental carving capacity was operationalized as a maximum number of industry structure, population, and housing that can sustain certain level of environmental quality of Seoul Metropolitan Area. The model developed in this paper consisted off sectors: population, housing, industry, land, and environmental sector. The model limits its main focus on the NO$_2$level of ambient air of Seoul. Carving capacity Seoul Metropolitan Area was estimated by figuring out the maximum number of population, industry structure, housing at an equilibrium point that sustain a desirable NO$_2$level. Based on the model estimation, several policy implications for a sustainable city management was discussed.

• 한국연초학회지
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• 제14권1호
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• pp.48-56
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• 1992

This studies were carried out to investigate the effects of leaf loading quantity and circulating air volume during bulk curing on the variation of physical and chemical characteristics in flue-cured tobacco. The results are as follows : 1. The content of sugar in cured leaves was decreased with more circulating air volume and leaf loading quantity at bulk curing. 2. Total nitrogen and protein nitrogen were decreased with less circulating air volume and more leaf loading quantity, while amino nitrogen was increased. 3. The contents of linolenic acid and linoleic acid were increased with more leaf loading quantity and oxalic acid and citric acid had a tendency of being increased in case of high circulating air volume. 4. In general, major aromatic compounds were increased through flue-curing. Relatively high content of solanone in case of lower air volume and less leaf loading were observed, while megastig matrienone was increased when leaf loading was small. 5. The more circulation air volume with leaf loading quantity caused lowering equilibrium moisture content and higher shatter index, which resulted in poor quality of cured leaves based on quality index, nitrogen number, taste index phillips index, and sugar-nicotine ratio.