• Bulletin of the Korean Chemical Society
• /
• 제32권11호
• /
• pp.3933-3940
• /
• 2011

General, fast, and efficient stitching methods for the synthesis of dendrimers with linear PEG units at a core, as dendritic-linear-dendritic materials, were developed. The synthetic strategy involved the click reaction between an alkyne and an azide. The linear core building blocks, three dialkyne-PEG units, were chosen to serve as the alkyne functionalities for dendrimer growth via click reactions with the azide-dendrons. These three building blocks were employed together with the azide-functionalized Fr$\acute{e}$chet-type dendrons in a convergent strategy to synthesize the Fr$\acute{e}$chet-type dendrimers with different linear core units. Their structure of dendrimers was confirmed by $^1H$ and $^{13}C$ NMR spectroscopy, IR spectroscopy, mass spectrometry, and GPC analysis.

• 경영과학
• /
• 제34권1호
• /
• pp.57-70
• /
• 2017

The phenomenon of increasing aging population is one of the crucial social and economic issues in these day. In this paper, drawn from the industrial application cases and relevant literatures, we present the typology of ICT convergent applications targeted for silver generation, referred as silver ICT. Subsequently, the contributional value of ICT as the enabling technology is estimated. We firstly conduct keyword search to collect currently used silver ICT applications. Secondly, drawn from the social welfare literature, we organize distinctive needs of the silver generations. Then, on the basis of task technology fit framework, typology of ICT enabled silver applications is organized through the fit of ICT in the sense of fulfilling those silver needs. Finally, using the industry input-output table figures, potential ICT contributions for silver ICT are estimated. The proposed silver ICT typology and ICT contributions provides useful insights for further research in the area of ICT convergence and silver market research.

• 한국자동차공학회논문집
• /
• 제21권6호
• /
• pp.108-116
• /
• 2013

Diesel engine injector is used for spraying the fuel into the cylinder chamber. Complex phenomenon like cavitation occurs from small scale domain, highly pressurized condition and rapid injection. Flow inside the nozzle affects the whole engine performance including combustion and exhaust, therefore understanding the flow inside the injector nozzle is very important. In this paper, cylindrical and convergent-divergent nozzles are suggested for nozzle types and their influences on nozzle internal flow and nozzle outlet characteristics will be analyzed by changing their outlet diameters.

• 제어로봇시스템학회논문지
• /
• 제16권11호
• /
• pp.1025-1028
• /
• 2010

This paper presents a new approach to analyze the stability of dynamic competitive markets within the framework of supervisory control of discrete event systems. A competitive market is representative of free market economy where it is well known that an invisible hand (also referred to as Walrasian auctioneer) always achieves an equilibrium of demand and supply. Upon the framework of supervisory control theory, this paper shows that Walrasian auctioneer is a stabilizing supervisor for a convergent competitive market, however a non-convergent competitive market (e.g. a free market under economic bubble and depression) controlled by Walrasian auctioneer may not be stable.

• 아동학회지
• /
• 제20권2호
• /
• pp.225-242
• /
• 1999

The psychometric properties of a preliminary version of the Friendship Quality Scale(FQS) were examined with data collected from 300 3rd and 5th grade children. Scores on the Self-Perception Scale were obtained to examine convergent validity. The FQS assesses friendship quality in 9 sub-scales, inclusive of 6 friendship functions. Factor analysis confirmed the 9 sudscale structure of the FQS for 5th graders, but 4 friendship functions instead of 6 were a better fit for 3rd graders. Except for one, the sub-scales showed relatively high internal consistency ; Cronbach ${\alpha}$ ranged from .70 to .93. Convergent validity was indicated by correlations between self-perception and sex differences in friendship functions. Friendship functions and satisfaction were related to self-perceptions in social acceptance, behavior, and global self-worth. Girls reported higher friendship functions and satisfaction in friendship than boys.

• 한국레이저가공학회지
• /
• 제18권3호
• /
• pp.6-8
• /
• 2015

Finishing process includes deburring, polishing and edge radiusing. It improves the surface profile of specimen and eliminates the alien substance on surface. Deburring is the elimination process for debris of edges. Polishing lubricates surfaces by rubbing or chemical treatment. There are two types for electron finishing. The one is using pulse beam. The other is using the convergent and scanning electron beam. Pulse type device appropriates the large area process. But it does not control the beam dosage. Scanning type device has advantages for dosage control and edge deburring. We design the convergence and scan type. It has magnetic lenses for convergence and scan device for scanning beam. Magnetic lenses consist of convergent and objective lens. The lenses are designed by the specification(beam size and working distance). In this paper, we evaluate the convergence performance by pattern process. Also, we analysis the results and important factors for process. The important factors for process are beam size, pressure, stage speed and vacuum. These results will be utilized into systematizing pattern shape and the factors.

• 한국전기전자재료학회논문지
• /
• 제21권4호
• /
• pp.381-387
• /
• 2008

Neutron production rate in spherically convergent beam fusion(SCBF) device as a portable neutron source strongly depends on the ion current and the grid cathode structure. In this paper, as the process of design and analysis, Design of Experiment(DOE) based on the results by Finite Element Method-Flux Corrected Transport(FEM-FCT) method is employed to calculate the ion current. This method is very useful to find optimal design conditions in a short time. Number of rings, radius of rings, and distance between the grid cathode and center are selected as control factors. From the results in the optimized model, the higher ion current is calculated and deeper potential well is also observed.

• Journal of applied mathematics & informatics
• /
• 제28권5_6호
• /
• pp.1467-1476
• /
• 2010

The aim of this paper is to propose a cubic convergent regula falsi iterative method for solving the nonlinear equation f(x) = 0, where f : [a,b] $\subset$ R $\rightarrow$ R is a continuously differentiable. In [3,6] a quadratically convergent regula falsi iterative methods for solving this nonlinear equations is proposed. It is shown there that both the sequences of diameters and iterative points sequence converge to zero simultaneously. So The aim of this paper is to accelerate further the convergence of these methods from quadratic to cubic. This is done by replacing the parameter p in the iteration of [3,5,6] by a function p(x) defined suitably. The convergence analysis is carried out for the method. The method is tested on number of numerical examples and results obtained shows that our methods are better and more effective and comparable to well-known methods.

• 여성건강간호학회지
• /
• 제12권3호
• /
• pp.204-209
• /
• 2006

Purpose: The Edinbergh Postnatal Depression Scale (EPDS) has seen widespread use in epidemiological and clinical studies. The objective of this research was to translate and to test the reliability and validity of the 10-item EDPS in Korea. Methods: Subjects were 145 women who were 6 to 10 weeks post delivery. To test reliability, the internal consistency was assessed by Cronbach's alpha coefficient. Validity testing was performed using convergent validity by Pearson's correlation. Data was gathered at 3 hospitals during Oct. 2005 after obtaining an informed consent. Result: The mean age of the subjects was 29.9 years. and the mean parity was 1.46 times. The mean EPDS score was 18.4. Reliability analysis showed a satisfactory result (Cronbach's alpha coefficient=.84). There were significant positive correlations between EPDS and Mills postnatal depression and anxiety check list scores as expected(r=.69, p<.001) and thus supported convergent validity. Conclusion: The study findings showed that the Korean version of the EPDS-10 is a reliable and valid instrument that can be used for measuring postnatal depression in Korea.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2019년도 전력전자학술대회
• /
• pp.386-387
• /
• 2019

본 논문에서는 단상 컨버터/3상 인버터 시스템에서 공통모드에 의한 누설전류를 분석하였다. 컨버터/인버터 시스템의 공통모드 전압은 시스템에 존재하는 기생 임피던스를 충방전함으로써 수 A의 누설전류를 발생시킨다. 이에 본 논문에서는 단상 컨버터/3상 인버터 시스템에서 컨버터 입력 측 변압기와 전동기의 기생 임피던스를 고려하여 누설전류를 분석하였으며, 누설전류를 감소하기 위해 공통모드 전압 저감하는 방법을 제안한다. 모의실험을 통하여 제안된 기법에 의한 누설전류의 저감효과를 확인하였다.