• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.765-766
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• 2006

The ecology of Physically Embedded Intelligent Systems (PEIS) is a new multi robotic framework conceived by integrating insights from the fields of autonomous robotics and ambient intelligence. A PEIS-Ecology is a network of intelligent robotic devices that can provide the user with assistance, information, communication, and entertainment services. In this paper we introduce the concept of PEIS Ecology, and illustrate a concrete realization of a PEIS-Ecology.

• The Journal of Information Systems
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• v.28 no.2
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• pp.73-92
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• 2019

Purpose This study conducted an empirical study on the influence of institutional mechanisms on the formation of customer trust among leading online businesses. This study focused on the construct of PEEIM(Perceived Effectiveness of e-Commerce Institutional Mechanisms) which is the perceived recognition of institutional mechanisms for e-Commerce in general and the construct of PEIS which is the perceived recognition of institutional mechanisms that are implemented by vendors. Design/methodology/approach The online and offline surveys were conducted for the leading online shopping vendors in Korea and 292 data were used for the empirical analysis. The research model was tested using partial least squares structural equation modeling (PLS-SEM) in this study. The full measurement model including the formative second-order constructs was examined with the exploratory factor analysis. The structural model was analyzed via a two-stage approach. To analyze the research model this study used Smart PLS 2.0 program. Findings The findings showed that PEEIM negatively moderates the relationship between satisfaction in vender and trust in vender, but had no moderating effect between trust in vender and repurchase intention. In addition, the institutional mechanisms of vendors(PEIS) have been shown to have a direct impact on the vender's trust.

• The Journal of Information Systems
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• v.30 no.2
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• pp.165-188
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• 2021

Purpose This study was conducted to identify the multidimensional role of institutional mechanisms in the linear relationship of satisfaction, trust and repurchase intention, which are used as an important concept in the research of e-commerce. To this end, a research model was proposed by combining concepts which are the concept of perceived effectiveness of institutional mechanisms for overall e-commerce environment(e.g., PEEIM) and the concep of perceived effectiveness of institutional structures(e.g., PEIS) of a specific marketplace based on the social cognitive theory. Design/methodology/approach This study was conducted by dividing the data into two groups to identify institutional mechanisms and trust-building relationships according to the institutional contexts inherent in e-commerce. The institutional contexts were set up for the top two online companies and the bottom two online companies according to the results of the open market brand assessment from 2018 to 2019 in South Korea. Findings The result of this study found that PEIS had a direct impact on trust in both high and low groups respectively whereas PEEIM presented different paradoxical results in high and low groups. In the relationship between the satisfaction and the trust in the vendor of the high group, PEEIM showed negative moderating effects but in the relationship between the trust and the repurchase intention of the low group PEEIM showed positive moderating effects.

• Journal of Pharmaceutical Investigation
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• v.34 no.4
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• pp.263-267
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• 2004

Branched and linear polyethylenimines (PEIs) have been studied as efficient and versatile agents for gene delivery in vitro and in vivo. PEIs exist in a linear or branched topology and are available in a wide range of molecular weight (Mw). Most studies have been done using PEIs with Mw higher than 10Kd. This study was aimed to test the transfection efficiency and the cell viability following gene delivery using PEI of Mw 2Kd, a relatively lower Mw cationic polymer. We used murine interleukin-2(mIL-2) plasmid DNA complexed with branched PEI 2Kd or 25Kd, and transfected them into a myoblast muscle cell line, C2C12. The cellular uptake of mIL-2 plasmid DNA was determined using quantitative polymerase chain reaction. RNA transcript levels were studied in the myoblast cells. Our results show that PEI 2Kd was as effective as PEI 25Kd in celluar gene delivery and transfection efficiency in C2C12 cells. Moreover, MTT assay indicated that PEI 2Kd/DNA complexes did not significantly reduce the cell viability regardless of N/P ratios. These results suggest that PEI of Mw 2Kd might play a role as effective and low toxic nonviral vector systems for muscular cell lines.

• Bulletin of the Korean Chemical Society
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• v.22 no.1
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• pp.46-52
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• 2001

To evaluate the non-ionic polymer, poly(ethylene glycol) (PEG), as a component in cationic copolymers for non-viral gene delivery systems, PEG was coupled to polyethylenimine (PEI). We present the effects of different degrees and shapes of pegylation of PEI on cytotoxicity, water solubility and transfection efficiency. This work reports the synthesis and characterization of a series of cationic copolymers on the basis of the conjugates of PEI with PEG. The modified molecules were significantly less toxic than the original polymer. Moreover, the chemical modification led to enhancement of their solubility. The comparison of pegylated PEIs with different degrees of derivation showed that all the polymers tested reached comparable levels of transgene expression to that of native PEI. As assessed by agarose gel electrophoresis, even highly substituted PEI derivatives were still able to form polyionic complexes with DNA. However, aside from an increase in solubility and retention of the ability to condense DNA, methoxy-PEG-modified PEIs resulted in a significant decrease in the transfection activity of the DNA complexes. In fact, the efficiency of the copolymer was compromised even at a low degree of modification suggesting that the PEG action resulting from its shape is important for efficient gene transfer. The mode of PEG grafting and the degree of modification influenced the transfection efficiency of PEI.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.347-352
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• 2005

This paper presents an evaluation model for the performance of Value Engineering Study (VES) for construction projects. The proposed model consists of 6 PEGs and 32 PEIs. The expertise of the proposed model was collected from VE experts in Taiwan using two-phase questionnaire survey. One real-life VES of construction projects was used to demonstrate how the proposed model works. The proposed model not only can be used by project owners to appraise the performance of VES team but also be used by the VES teams to conduct self-diagnosis, improvement, and motivation for achieving better performance. Additionally, the proposed model is capable of: (1) clarifying the defects of VES and avoiding committing same mistakes, (2) assisting inexperience team members to implement VES and catch the critical issues of a VES.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.376-378
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• 2008

This paper covers that modem performance test is effected by traffic and analysis of the result in TETRA network. The SDS is a method of the between PEIs transmission. And only SDS message type-4 is used to test. The range of the SDS message data length is from 10 to 140 bytes with an increment of 10 bytes. For each length transmitted 1000 times for each delay of inter-transmissions 0.5 second, 1.0 second and 1.5 second. The modem used in the test is the Unimo MU-1000MD by UNIMO Corp.

• Bulletin of the Korean Chemical Society
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• v.28 no.1
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• pp.95-98
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• 2007

Polyethylenimine (PEI) has been widely investigated for delivery of DNA into cells. It was previously reported that there were at least two types of cytotoxicity in PEI-mediated gene delivery, immediate and delayed toxicities. PEI-mediated gene delivery protocols use net cationic complexes with an excess of PEI to maintain equilibrium between the complexed and dissociated forms in solution. In this study, toxicity of free PEI or PEI/ DNA complex was investigated. Human embryonic kidney 293 cells were incubated with free PEI or PEI/DNA complex for 4 hrs. Then, the cells were analyzed at 6, 24, 48, and 96 hrs after the incubation. In MTT assay, the viability of the cells incubated with PEI/DNA complex was continuously decreased with time, while that of the cells incubated with free PEI was not. On the contrary, the expression level of the luciferase gene increased gradually along with time. Release of DNAs from the complexes for transcription produces free PEIs in the cells. This process may proceed slowly due to high charge density of PEI and may be related to delayed toxicity. In addition, apoptotic cells were observed only in the cells incubated with the PEI/DNA complex from 24 hrs after the incubation. The results suggest that PEI/DNA complex contributes to the delayed toxicity by inducing apoptosis and that the delayed toxicity may be related to decomplexation of the complexes in the cells.

• Polymer(Korea)
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• v.29 no.3
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• pp.231-236
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• 2005

Amino terminated polyetherimide (AP-PEI) has been synthesized using 2,2'-bis [4-(3,4-dicarboxyphenoxy)-phenyl]propane dianhydride (BPADA) and m-phenylenediamine. Polyetherimide containing pendant carboxy group (CP-PEI) has also been synthesized by the reaction of BPADA, m-phenylenediamine and 3,5-diaminobenzoic acid. The modified PEIs were used as toughening agent for diglycidyl ether of bisphenol-A epoxy resin which was cured with nadic methyl anhydride (NMA). Thermal properties, fracture toughness ($K_{IC}$) and solvent resistance of toughened epoxy resin were measured. The $K_{IC}$ of epoxy resin containing 20 phr of AT-PEI was 2.88$MPa{\cdot}m^{0.5}$ without sacrificing thermal properties. The $K_{IC}$ of epoxy resin which contained 20 phr of CP-PEI was 2.82$MPa{\cdot}m^{0.5}$.

• Journal of Pharmaceutical Investigation
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• v.35 no.1
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• pp.17-23
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• 2005

Polyethylenimine (PEI) has been used as cationic polymers for efficient gene transfer without the need for endosomolytic agents. Various kinds of PEIs with different molecular weight were tested in order to investigate the effects of the molecular weight of PEI on the transfection efficiency and cell cytotoxicity. The ${\beta}-galactosidase$ expression $(pCMV-{\beta}-gal)$ plasmid was used as a model DNA. Complex formation between PEI and pDNA was assessed by 1% agarose gel electrophoresis method. Particle size and zeta-potential of complexes were determined by electrophoretic light scattering spectrometer. In vitro transfection efficiency was assayed by measuring ${\beta}-galactosidase$ activity. Cell cytotoxicity was determined by MTT assay. Particle sizes of the complexes became smaller on increasing molecular weights of PEI and N/P ratios. Surface potential of complexes was increased as the molecular weight of PEI increased. Transfection efficiency of $pCMV-{\beta}-ga1$ on the HEK 293 cells was greatest with PEI 25 K system but having the lowest cell viability. PEI with high molecular weight showed higher transfection efficiency and cell viability than PEI with low molecular weight.