• Title/Summary/Keyword: IT Diffusion

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Prediction of Absorption Behavior of Carbon Dioxide on Membrane Contactor (분리막 접촉기를 통한 이산화탄소 흡수거동 예측)

  • Cho, In-Gi;Ahn, Hyo-Seong;Hahm, Moon-Ky;Kim, I.H.;Lee, Yong-Taek;Park, You-In;Lee, Kew-Ho
    • Membrane Journal
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    • v.10 no.1
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    • pp.39-46
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    • 2000
  • To predict the absorption behavior of carbon dioxide on membrane contactor, an aqueous potassium carbonate solution as an absorbent. The reversible reactions of carbon dioxide with chemicals were considered, and the physicochemical properties of reaction rate constants, equilibrium constants, solubilities and diffusion coefficients were used as a function of concentration of carbon dioxide and the temperature. A non-wetted mode was also used as an operating condition of the membrane contactor. In these operation conditions, the effect of the following system parameters were studied : the concentration of potassium carbonate, the velocity of the absorbent and the pressure of the mixture gas. The absorption behavior of carbon dioxide caused by a facilitated transport was observed as the increment of the concentration of the absorbent. The absorption rate of carbon dioxide was increased as the absorbent velocity was increased. Furthermore, it was found that the pressure if the mixture gas and the reuse number of absorbent affect severely the absorption rate of carbon dioxide. The absorption behavior was successfully predicted by the computer simulation using the system parameters which are important for design and operation of the membrane contactor.

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Effects of Aged Black Garlic Extracts on the Tight Junction Permeability and Cell Invasion in Human Gastric Cancer Cells (흑마늘 추출물이 인체위암세포의 tight junction 투과성 조절과 세포 침윤성 억제에 미치는 영향)

  • Shin, Dong-Yeok;Yoon, Moo-Kyoung;Choi, Young-Whan;Gweon, Oh-Cheon;Kim, Jung-In;Choi, Tae-Hyun;Choi, Yung-Hyun
    • Journal of Life Science
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    • v.20 no.4
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    • pp.528-534
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    • 2010
  • Garlic (Allium sativum) has been well-known as a folk remedy for a variety of ailments since ancient times, and it is well documented that enhanced garlic consumption leads to a decrease in incidences of cancer. Tight junctions (TJs) are critical structures for the maintenance of cellular polarity, acting as paracellular permeability barriers and playing an essential role in regulating the diffusion of fluid, electrolytes and macromolecules through the paracellular pathway. Matrix metalloproteinases (MMPs) have been implicated as possible mediators of invasiveness and metastasis in some cancers. In this study, we investigated the potential effects of water extract of aged black garlic (ABG) on the correlation between tightening of TJs and anti-invasive activity in human gastric carcinoma AGS cells. The inhibitory effects of ABG on cell motility and invasiveness were found to be associated with increased tightness of TJs, which was demonstrated by an increase in transepithelial electrical resistance. Additionally, the activities of MMP-2 and -9 in AGS cells were inhibited by treatment with ABG, and this was also correlated with a decrease in the expression of their mRNA and proteins. Furthermore, RT-PCR and immunoblotting results indicated that ABG repressed the levels of the claudin proteins, major components of TJs that play a key role in the control and selectivity of paracellular transport. In conclusion, these results suggest that ABG treatment may inhibit tumor metastasis and invasion, and therefore may act as a dietary source to decrease the risk of developing cancer.

Modified Local Color Transfer with Color Category Map (컬러 카테고리 맵을 이용한 수정된 지역적인 색변환)

  • Ha, Ho-Gun;Kyung, Wang-Jun;Kim, Dae-Chul;Ha, Yeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.49 no.3
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    • pp.67-73
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    • 2012
  • Local color transfer is the process of assigning a given color to a local region in a target image. The local region that contains the given color has to be segmented. Conventionally, the segmentation of the corresponding local region in a target image is based on the color distance. The region which is the closest in color distance is separated. However, since the close range of color distance separating a given color from target image is ambiguous and uncertain, color distortion is often generated around a separated local region. Therefore, this paper addresses the problem of segmentation in a local color transfer. To prevent color distortion, a modified color influence map is proposed with color categories. First, the target image is roughly segmented using a color category map, which groups similar colors in color space. It restricts the color transfer to a specific color category according to a given color. Second, modified color influence map assigning different weight to lightness and chroma, respectively, is used instead of Euclidian color distance. Then, by combining a modified color influence map and color category map filtered with anisotropic diffusion, a local region that contains a given color can be segmented more strictly than conventional method.

The influence of Social Norm and Critical Mass on Online Game User's Word of Mouth (사회규범과 크리티컬 매스가 온라인 게임 이용자의 구전의도에 미치는 영향에 관한 연구)

  • Bae, Jungho;Kim, Moon Seop
    • The Journal of the Korea Contents Association
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    • v.14 no.4
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    • pp.355-367
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    • 2014
  • The purpose of this research is to find the specific structure with factors that affect online game users' positive word of mouth(WOM) for online game companies to maintain existing and new users. In previous studies the influence of characteristics of online games and attributes of users on intention to play online games is mainly focused on. However online games are products with communication on network, so that critical mass through diffusion as well as the use of product by individual consumers is important issues. Therefore, it is necessary to consider network externality effect that the more value can be obtained by more game users. The authors verified that the influence of the variables like social mass and critical mass, affecting consumers' attitude and WOM. According to the research results, social norm and critical mass have significant influence on positive attitude and WOM intention for online games. Another results verified that social norm and users' attitude affect positive WOM intention directly. These results suggest managerial implication regarding social norm and critical mass to online game companies that desire for WOM to get more online game users.

Wetland Conservation Action Plan of Local Government: Gyeongsangnam Province, South Korea (지방정부의 습지보전실천계획 수립과 과제 현황분석: 경상남도를 대상으로)

  • Kim, Ji Yoon;Do, Yuno;Lee, Chan-Woo;Choi, Lee-Ryong;Joo, Gea-Jae;Jo, Hyunbin
    • Journal of Wetlands Research
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    • v.17 no.3
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    • pp.245-250
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    • 2015
  • We systematically analyzed the Wetland Conservation Action Plan of Gyeongsangnam Province to evaluate conservation status in local government level. Project topics were categorized into 1) wetland infrastructure, 2) wetland conservation and wise use, 3) education and awareness, and 4) conservation framework. From 2010 to 2013, 42 projects (145 cases, 88,899 million won) were implemented by 14 affiliated organizations under Gyeongsangnam Provincial Government. The number of projects and budget size has been decreased over 4 years, besides most of main projects were continued. The budgets were largely used for wetland project of cities and counties. Development and implementation of various conservation projects may have considerable potential values in wetland conservation, while it is still difficult to assess their overall effectiveness in the society. Diverse wetland management practices in Gyeongsangnam Provincial Government have accumulated fundamental practices and knowledge for an effective local conservation. These administrative experiences will further benefit other local government to establish wetland management framework. To accelerate policy diffusion to other local governments, Gyeongsangnam Province needs to promote and share leading experiences and information of wetland conservation. Enhanced local government framework by the legislation at central government will further support country-level management plans and practices.

The Impact of Changes in Social Information Processing Mechanism on Social Consensus Making in the Information Society (정보화사회에 있어서 사회적 정보처리 메커니즘의 변화가 사회적 컨센서스 형성에 미치는 영향에 대한 연구)

  • Jin, Seung-Hye;Kim, Yong-Jin
    • Information Systems Review
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    • v.13 no.3
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    • pp.141-163
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    • 2011
  • The advancement of information technologies including the Internet has affected the way of social information processing as well as brought about the paradigm shift to the information society. Accordingly, it is very important to study the process of social information processing over the digital media through which social information is generated, distributed, and led to social consensus. In this study, we analyze the mechanism of social information processing, identify a process model of social consensus and institutionalization of the results, and finally propose a set of information processing characteristics on the internet media. We deploy the ethnographic approach to analyze the meaning of group behavior in the context of society to analyze two major events which happened in Korean society. The formation process of social consensus is found to consist of 5 steps: suggestion of social issues, selective reflection on public opinion, acceptance of the issues and diffusion, social consensus, and institutionalization and feedback. The key characteristics of information processing in the Internet is grouped into proactive response to an event, the changes in the role of opinion leader, the flexibility of proposal and analysis, greater scalability, relevance to consensus making, institutionalization and interaction. This study contributes to the literature by proposing a process model of social information processing which can be used as the basis for analyzing the social consensus making process from the social network perspective. In addition, this study suggests a new perspective where the utility of the Internet media can be understood from the social information processing so that other disciplines including politics, communications, and management can improve the decision making performance in utilizing the Internet media.

Analysis on the Success Factors of e-CRM using Analytical Hierarchy Process (AHP) (분석적 계층 프로세스(AHP) 기법을 이용한 e-CRM의 성공요인 분석)

  • Shin, Dong-Hyuk;Kim, Seong-Jin;Ahn, Hyun-Chul
    • CRM연구
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    • v.4 no.1
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    • pp.19-34
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    • 2011
  • Recently, companies have interests in the adoption and diffusion of customer relationship management(CRM). And, as information and communication technologies and Internet technologies proliferate, they also have interests in e-CRM, which implements CRMusing online communication channels. Until now, many researchers have tried to identify the success factors of CRM and evaluate their relative importance. However, only a few studies have dealt with the success factors of e-CRM. For this reason, we aim at identifying and evaluating the success factors of e-CRM in order to provide the companies with the guideline for preparing the implementation of e-CRM. Our study adopts analytical hierarchy process(AHP) as a tool for evaluating these factors because it has been widely applied and validated for a long time. Whereas prior studies have analyzed the success factors from the organizational and technological perspective, our study analyzes them from the functional perspective. As a result, we found that the companies should manage all the CRM components including analytic-operational-collaborative CRM in good balance. Also, we found that the sufficient support from CEO, the acquisition of good quality customer data, and theonline processing capability for responding customers' requests effectively are important for the success of e-CRM.

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Effect of the Crystalline Phase of Al2O3 Nanoparticle on the Luminescence Properties of YAGG:Ce3+ Phosphor under Vacuum UV Excitation (진공자외선 여기에 의한 YAGG:Ce3+ 형광체의 광발광 특성에 미치는 Al2O3 나노입자 원료의 결정상의 영향)

  • Wu, Mi-Hye;Choi, Sung-Ho;Jung, Ha-Kyun
    • Korean Journal of Materials Research
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    • v.22 no.4
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    • pp.195-201
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    • 2012
  • $Ce^{3+}$-doped yttrium aluminum gallium garnet (YAGG:$Ce^{3+}$), which is a green-emitting phosphor, was synthesized by solid state reaction using ${\alpha}$-phase or ${\gamma}$-phase of nano-sized $Al_2O_3$ as the Al source. The processing conditions and the chemical composition of phosphor for the maximum emission intensity were optimized on the basis of emission intensity under vacuum UV excitation. The optimum heating temperature for phosphor preparation was $1550^{\circ}C$. Photoluminescence properties of the synthesized phosphor were investigated in detail. From the excitation and emission spectra, it was confirmed that the YAGG:$Ce^{3+}$ phosphors effectively absorb the vacuum UV of 120-200 nm and emit green light positioned around 530 nm. The crystalline phase of the alumina nanoparticles affected the particle size and the luminescence property of the synthesized phosphors. Nano-sized ${\gamma}-Al_2O_3$ was more effective for the achievement of higher emission intensity than was nano-sized ${\alpha}-Al_2O_3$. This discrepancy is considered to be because the diffusion of $Al^{3+}$ into $Y_2O_3$ lattice is dependent on the crystalline phase of $Al_2O_3$, which affects the phase transformation of YAGG:$Ce^{3+}$ phosphors. The optimum chemical composition, having the maximum emission intensity, was $(Y_{2.98}Ce_{0.02})(Al_{2.8}Ga_{1.8})O_{11.4}$ prepared with ${\gamma}-Al_2O_3$. On the other hand, the decay time of the YAGG:$Ce^{3+}$ phosphors, irrespective of the crystalline phase of the nano-sized alumina source, was below 1 ms due to the allowed $5d{\rightarrow}4f$ transition of the $Ce^{3+}$ activator.

Analysis of Trace Copper Metal at The Electrode Consisting of Carbon Nanotube using Stripping Voltammetry (벗김전압전류법을 이용한 카본나노튜브 전극에서의 구리 분석)

  • Choi, Chang-Kun;Jung, Young-Sam;Kim, Nack-Joo;Pak, Dae-Won;Chung, Kun-Yong;Kim, Lae-Hyun;Kwon, Yong-Chai
    • Korean Chemical Engineering Research
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    • v.50 no.5
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    • pp.933-937
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    • 2012
  • In the present study, we evaluate the sensitivity and optimal stripping voltammetry (SV) conditions of copper (Cu), which is one of the main trace heavy metals inducing the environmental contamination, using carbon nanotube (CNT) electrode. In addition, the reaction mechanism of stripping reaction of Cu is investigated. The electrochemical analyses such as squarewave stripping voltammetry (SWSV) and linear scan voltammetry (LSV) are used for the evaluations. As a result of that, the best SWSV conditions like squarewave amplitude of 15 mV, frequency of 60 Hz, deposition potential of -1.0V vs. Ag/AgCl and deposition time of 200s are determined with the measured Cu sensitivity of $1.824{\mu}A/{\mu}M$. As a driving force affecting the stripping reaction of Cu, surface reaction is more dominant one than diffusion. These results are compared with other reference results and it is confirmed that our suggested CNT electrode gives rise to better Cu sensitivity result than other references.

A research on the way of spreading creative design thinking by Semantic Network -Focus on product design- (의미 네트워크 개념을 통한 창의적 디자인 사고의 확산방법에 관한 연구 -제품디자인 중심으로-)

  • Zhang, Ye;Zheng, Hua;Eune, Ju-Hyun
    • 한국HCI학회:학술대회논문집
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    • 2009.02a
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    • pp.1137-1144
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    • 2009
  • Creativity, the ability to produce through imaginative skill, is pursued by all designers. However, originality does not refer to absolute novelty. In this age, information is shared and disseminated. Creation of works is an activity to re-establish all shared information and reorganize relationship among things. Therefore, a new design is a product of reorganization rather than originality. Moreover, designers can generate ideas different from each other because they individually espouse different system of knowledge. From such perspective, a very important task of designers is to explore methods of expanding design thinking that can enhance the ability to new connection among things in the process of assimilation and modification. The task can be carried out by identifying characteristics and limits of their unique system of knowledge. Therefore, it is necessary to seek methods of expanding design thinking for efficient cognitive activities. In explaining human knowledge, this study applied semantic network, a method used in cognitive science for creating structure, and the method of expanding design thought was proposed by corresponding method of design conceptualization. By organizing, categorizing, and flexibly combining and modifying the methods of design thinking conceptualization and expansion generated by this study, strengths of each method were enhanced and limits of each method were overcome to enable more effective design thinking. In this study, the method of expansion was used when connecting of nodes cannot be sustained after using each method of conceptualization. By avoiding unique method of thinking through diversification and vitalization of conditional points, efficient design thinking was achieved. The value of this study lies in the fact that the proposed method of expanding thinking using the mechanism of network enhances the ability to establish new connections in the process of assimilation and modification.

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