• Korean Chemical Engineering Research
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• v.49 no.5
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• pp.652-656
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• 2011

Thin film of titania nanotubes(TNT) and titania nanofilms(TNF) was fabricated by anodizing for the study of the photo-catalytic reaction(PC) and photoelectrocatalytic reaction(PEC). Removal efficiency of methylene blue was investigated by UV radiation on the TNT coated titanium plate. Removal efficiency was increased with longer TNT length. Degradation efficiency of the PEC reaction was less sensitive than that of PC reaction. And Effect of TNT length is relatively small. Titania nanofilms(TNF) showed low efficiency than TNT. The efficiency drop of PC was larger than that of PEC.

• Clinical and Experimental Pediatrics
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• v.58 no.12
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• pp.466-471
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• 2015

Purpose: This study attempted to examine parental satisfaction with pediatric emergency care (PEC) in Korea and investigate the features influencing overall satisfaction. Methods: A nationwide, cross-sectional survey was conducted among parents who had taken their children to an Emergency Department (ED) in the three years prior to the study. A 21-item, structured questionnaire was administered to the parents through a web-based system. Participants' satisfaction levels and the strength of the association between PEC components and overall satisfaction were rated using a 7-point Likert scale. Results: In total, 1,000 parents participated in the survey, of which 402 (40.2%) stated that they were generally satisfied with the delivered PEC. Female participants, mothers, and parents with low-acuity patients were more likely to be dissatisfied with the delivered PEC. Although the ED environment was the lowest level of satisfaction, it did not significantly influence the respondents' overall levels of satisfaction. The most influential factors in terms of overall satisfaction were "nurses' professionalism" and "doctors' attitude and proper explanation". Conclusion: Parents' overall level of satisfaction with PEC is relatively low and is closely related to factors associated with ED personnel.

• Korean Journal of Materials Research
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• v.30 no.9
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• pp.441-446
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• 2020

Synthesizing nanostructured thin films of oxide semiconductors is a promising approach to fabricate highly efficient photoelectrodes for hydrogen production via photoelectrochemical (PEC) water splitting. In this work, we investigate the feasibility as an efficient photoanode for PEC water oxidation of zinc oxide (ZnO) nanostructured thin films synthesized via a simple method combined with sputtering Zn metallic films on a fluorine-doped tin oxide (FTO) coated glass substrate and subsequent thermal oxidation of the sputtered Zn metallic films in dry air. Characterization of the structural, optical, and PEC properties of the ZnO nanostructured thin film synthesized at varying Zn sputtering powers reveals that we can obtain an optimum ZnO nanostructured thin film as PEC photoanode at a sputtering power of 40 W. The photocurrent density and optimal photocurrent conversion efficiency for the optimum ZnO nanostructured thin film photoanode are found to be 0.1 mA/㎠ and 0.51 %, respectively, at a potential of 0.72 V vs. RHE. Our results illustrate that the ZnO nanostructured thin film has promising potential as an efficient photoanode for PEC water splitting.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.682-685
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• 2002

VoIP(Voice over IP) Technology is highlighted because of easy adopting the value added services related voice In this paper, we described the Internet telephony service based on SIP. Especially, we described the extension for re-INVITE function. Re-INVITE function is useful for cail transfer service or conference service.

• Macromolecular Research
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• v.14 no.3
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• pp.267-271
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• 2006

Polyelectrolyte complex films were prepared with two compounds, chitosan and poly(ethylene glycol)-monosuccinate, using a casting in order to synthesize a polyelectrolyte complex film with various mole ratios of chitosan and poly(ethylene glycol)-monosuccinate. The solution properties of isolated PEC were investigated for the effects of FTIR, pH value, Brookfield viscosity and cell viability assay using MTT staining. The PEC films were evaluated for mechanical properties by typical stress-strain curve, far thermal properties by DSC and TGA and for surface morphology Properties by SEM. Furthermore, the surface resistance, moisture regain and water content of the films were characterized. The solution properties were affected by several factors including the chitosan content in the PEC, the mixing ratio of PEG and chitosan, and pH. Several PEC in acidic conditions exhibited film formation under appropriate conditions of mixing ratio and chitosan concentration in the mixing process. These PEC films were found to have sufficiently flexible and stable properties due to their hydrophilic structure, which was farmed by the oppositely charged interaction between PEG-MS and chitosan matrix. The results showed the potential applicability of chitosan and poly(ethylene glycol)-monosuccinate films as a biocompatible polymer.

• Korean Journal of Materials Research
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• v.32 no.1
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• pp.30-35
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• 2022

The development of advanced materials to improve the efficiency of photoelectrochemical (PEC) water splitting paves the way for widespread renewable energy technologies. Efficient photoanodes with strong absorbance in visible light increases the effectiveness of solar energy conversion systems. MoS₂ in a two-dimensional semiconductor that has excellent absorption performance in visible light and high catalytic activity, showing considerable potential as an agent of PEC water splitting. In this study, we successfully modulated the MoS₂ morphology on indium tin oxide substrate by using the metalorganic chemical vapor deposition method, and applied the PEC application. The PEC photocurrent of the vertically grown MoS₂ nanosheet structure significantly increased relative to that of MoS₂ nanoparticles because of the efficient transfer of charge carriers and high-density active sites. The enhanced photocurrent was attributed to the efficient charge separation and improved light absorption of the MoS₂ nanosheet structure. Meanwhile, the photocurrent property of thick nanosheets decreased because of the limit imposed by the diffusion lengths of carriers. This study proposes a valuable photoelectrode design with suitable nanosheet morphology for efficient PEC water splitting.

• Steel and Composite Structures
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• v.45 no.1
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• pp.51-66
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• 2022

This paper presents the axial compression behavior of partially encased composite (PEC) columns using H-shaped structural steel. In the experimental program, a total of eight PEC columns with H-shaped steel sections of different flange and web slenderness ratios were tested to investigate the interactive mechanism between steel and concrete. The test results showed that the PEC columns could sustain the load well beyond the peak load provided that the flange slenderness ratio was not greater than five. In addition, the previous analytical model was extended to predict the axial load-strain relationships of the PEC columns with H-shaped steel sections. A good agreement between the predicted load-strain relationships and test data was observed. Using the analytical model, the effects of compressive strength of concrete (21 to 69 MPa), yield strength of steel (245 to 525 MPa), slenderness ratio of flange (4 to 10), and slenderness ratio of web (10 to 25) on the interactive mechanism (K_h = confinement factor for highly confined concrete and K_w = reduction factor for steel web) and ductility index (DI = ratio between strain at peak load and strain at proportional load) were assessed. The numerical results showed that the slenderness of steel flange and yield strength of steel significantly influenced the compression behavior of the PEC columns.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11b
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• pp.1293-1296
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• 2003

최근 인터넷의 급속한 보급으로 인해 다양한 서비스들이 제공되고 있으며 이에 따라 각 서비스와 장치들을 구별하기 위한 다수의 주소 체계가 사용되고 있다. 전자 메일, 인터넷 전화, 인터넷 팩스 등 다양한 인터넷 정보 자원 및 서비스에 대해 단일의 접근성을 제공하는 ENUM 기술은 사용자들의 서비스 이용 편의성을 향상시키는 기술로써 많은 관심을 끌고 있다. 본 논문은 RFC2916에 따른 ENUM 서비스를 제공하기 위하여 SIP에서 요구되는 기능에 관한 설계를 기술한다.

• Journal of Aerospace System Engineering
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• v.5 no.2
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• pp.1-7
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• 2011

On this study, applicable aircraft pitot-static system airworthiness requirements and flight test techniques for PEC(Position Error Correction) to KAS Part 23 airworthiness standards are introduced. Also, pros and cons, applicable test conditions, test procedures and required test parameters of each flight test techniques are reviewed on this study.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.6
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• pp.563-569
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• 2009

In this paper, four different types of pulsed eddy current(PEC) probe are designed and their performance of detecting wall thickness reduction is compared. By using the backward difference method in time and the finite element method in space, PEC signals from various thickness and materials are numerically calculated and three features of the signal are selected. Since PEC signals and features are obtained by various types and sizes of probe, the comparison is made through the normalized features which reflect the sensitivity of the feature to thickness reduction. The normalized features indicate that the shielded reflection probe provides the best sensitivity to wall thickness reduction for all three signal features. Results show that the best sensitivity to thickness reduction can be achieved by the peak value, but also suggest that the time to peak can be a good candidate because of its linear relationship with the thickness variation.