• Archives of Plastic Surgery
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• 제45권4호
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• pp.340-344
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• 2018

Background In performing extended latissimus dorsi (ELD) flap procedures, a skin paddle design on the bra line helps reduce visible scarring. This improves the patient's satisfaction with the outcome. However, such a design leads to a longer operation time and increased fatigue of the surgeon due to the narrow operative field. In this study, the authors propose a method that elongates the axillary incision line posteriorly by 1.5 cm from the lateral border of the latissimus dorsi muscle. We examined whether this method could shorten the operation time and compared the incidence of complications between patients who underwent this novel procedure and patients who underwent the traditional procedure. Methods In this study of patients who underwent ELD flap procedures for immediate breast reconstruction, 89 underwent surgery with the elongated axillary incision and 45 underwent surgery without the elongated incision. The total operation time and complications were retrospectively examined based on the patients' medical records, and we examined whether there was any statistically significant difference in the total operation time. Results In the experimental group with the elongated axillary incision, the operation time ranged from 125 to 255 minutes (median, 175 minutes). In contrast, in the control group without the elongated axillary incision, the operation time ranged from 142 and 340 minutes (median, 205 minutes). The operation time was statistically significantly different between the two groups, and no significant complications were observed in the experimental group. Conclusions Elongation of the axillary incision alone may shorten the operation time of the ELD flap procedure without causing additional complications.

• Journal of Electrical Engineering and Technology
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• 제9권1호
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• pp.15-26
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• 2014

This paper proposes a Modified Particle Swarm Optimization with Time Varying Acceleration Coefficients (MPSO-TVAC) for solving economic load dispatch (ELD) problem. Due to prohibited operating zones (POZ) and ramp rate limits of the practical generators, the ELD problems become nonlinear and nonconvex optimization problem. Furthermore, the ELD problem may be more complicated if transmission losses are considered. Particle swarm optimization (PSO) is one of the famous heuristic methods for solving nonconvex problems. However, this method may suffer to trap at local minima especially for multimodal problem. To improve the solution quality and robustness of PSO algorithm, a new best neighbour particle called 'rbest' is proposed. The rbest provides extra information for each particle that is randomly selected from other best particles in order to diversify the movement of particle and avoid premature convergence. The effectiveness of MPSO-TVAC algorithm is tested on different power systems with POZ, ramp-rate limits and transmission loss constraints. To validate the performances of the proposed algorithm, comparative studies have been carried out in terms of convergence characteristic, solution quality, computation time and robustness. Simulation results found that the proposed MPSO-TVAC algorithm has good solution quality and more robust than other methods reported in previous work.

• 동굴
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• 제90호
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• pp.35-56
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• 2009

본 연구의 목적은 동굴환경의 황폐화에 대한 지속가능한 동굴의 연구, 관광 및 보존을 위하여 첨단정보화 기술인 유비쿼터스 정보기술을 활용한 새로운 차원의 동굴시스템을 제시하는데 있다. 이러한 환경문제를 극복할 수 있는 방안으로 첫째, 동굴에 대한 법제도나 조례 등으로 강력한 관리방안이 제시되거나 휴식년제 도입 등으로 행정적인 방안이 있으며, 둘째, 최첨단 정보기술을 적용하여 효율적이고 지속가능한 동굴의 관리로 지하동굴 자원의 청정환경을 도모하는 방법이 있다. 유비쿼터스 동굴의 구축에는 첨단 자동정보시스템 인 감지시스템(USN), 모니터링시스템(RFID/UFID), 무선통신시스템(WiBro/WiFi), 공간정보시스템(GIS), 항공레이저시스템(LiDAR), 저열 조명시스템(ELD) 및 통합관리시스템 등이 적용되었다. 이러한 유비쿼터스 동굴 구현에 필요한 첨단화 정보기술분야의 산업적인 융합에 의한 차세대 동굴살리기 명품솔류션 구현을 통하여 공간정보기반의 유비쿼터스 동굴관리시스템의 모델을 제시하였다. 따라서 u-cave모델은 정책의 적용에 따라 동굴의 자연관리, 생태관리, 시설관리, 관광관리, 문화관리 및 소득창출 등의 시너지 효과를 달성할 수 있는 것으로서 동굴의 자연환경보존 기반의 수단으로서 기여 될 수 있다.

• 한국인터넷방송통신학회논문지
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• 제16권2호
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• pp.181-188
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• 2016

본 논문은 경제급전 최적화 문제에 개별 발전회사별로 독립적으로 경제급전을 수행하는 방법에 비해 중앙에서 통합하여 경제급전 최적화를 수행하는 경우가 보다 경제적임을 보였다. 이 경우에 적용된 알고리즘으로 밸브지점으로 발전량을 조절하는 균형방법을 수행한 후 발전량을 감소시킬 때의 비용 감소분과 증가시킬 때의 비용 증가분 차이로 발전량을 상호 교환하는 방법으로 최적화를 수행하였다. 10대, 13대과 40대-발전기를 독립적으로 운영하는 경우와 통합된 63대-발전기를 경제급전하는 경우를 비교한 결과 통합운영 방법이 독립적 경제급전에 비해 발전비용을 획기적으로 감소시켜 경제적인 이익을 극대화 시킬 수 있음을 보였다.

• E2M - 전기 전자와 첨단 소재
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• 제10권2호
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• pp.150-155
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• 1997

Powder type electroluminescent device(P-ELD) in this study was prepared by printing method. P-ELDs were basically composed of phosphor, insulator and transparent conducting layer. The phosphor powder was prepared by sintering the mixture of ZnS as a host, Cu as an activator, and NaCl as a flux for co-activator and enhancement of growth of the phosphor particles. The phosphor layer was made by printing the paste of the cyanoethylpullan as a binder and the ZnS system phosphor powder. In order to evaluate the luminescence characteristics of ZnS P-ELD, applied voltage - luminance(V-L), frequency-luminance(f-L), and relative luminance spectra(L- .lambda.) characteristics were measured. The experimental results show that luminance increased with increasing the applied voltage and frequency. It can be explained in terms of the potential barrier formed between ZnS and CuS. Two emission peaks in luminance-wavelength spectra measured at applied voltage of 100 $V_{rms}$ were observed at 500nm as a primary peak and 460nm as a secondary peak, respectively.y.

• 한국어교육
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• 제29권1호
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• pp.163-197
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• 2018

The present study suggests ways to improve the Korean proficiency screening test through an analysis of WIDA tests. A review of WIDA Screener, WIDA MODEL, and W-APT reveals that each of these three tests consists of four or five tests, corresponding to grade-level clusters. In addition, the WIDA screening tests assess both English for social communication and academic English, according to WIDA's five English Language Development (ELD) standards. Thematic folders of the ELD standards have different ranges of item difficulty, and the WIDA screening tests are adaptive tests. Lastly, the writing tests consist of performance-based tasks, and the rubric is holistic. As suggestions for improvement for Korean screening tests of the KSL curriculum, this study proposes (a) to devise items to assess academic Korean, so as to evaluate students' overall proficiency more accurately, (b) to utilize an adaptive method to screen students' proficiency more efficiently, and (c) to revise the writing tasks and rubric of the current KSL screening tests.

• 공업화학
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• 제9권5호
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• pp.710-714
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• 1998

Poly(p-phenylene vinylene), PPV를 발광층으로 하고 전자수송층(electron transport layer, ETL)이 도입된 이중 접합구조 유기 전기발광소자(electroluminescence device, ELD)를 제작하고 전기 발광 특성을 조사하였다. 전자 수송제로는 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole(PBD)를 사용하고 이를 분산시킬 기재 고분자(matrix polymer)로는 stilbene계 공단량체를 포함하는 poly(styrene-co-p-vinyl-trans-stilbene (PVTS)), poly(styrene-co-MeO-PVTS) 및 poly(styrene-co-MeO-ST)를 합성하였다. 이들 재료를 이용하여 이종 접합구조 ELD를 제조하였으며 poly(styrene-co-PVTS)를 기재 고분자로 쓴 EL 소자가 최대의 휘도를 나타냄을 확인하였다. Poly(styrene-co-MeO-PVTS) 및 poly(styrene-co-MeO-ST) 등 전자 주게 성질을 가진 methoxy기를 함유하는 기재 고분자를 쓴 EL 소자는 전자 수송층이 없는 ITO/PPV/Mg 단층 소자와 휘도가 유사 혹은 낮게 나타났다. Poly(styrene-co-PVTS)를 ETL에 쓴 EL 소자에 있어서 styrene보다 긴 conjugation 길이의 증가가 EL 발광 스펙트럼에 미치는 영향은 크지 않고 실제 발광은 PPV에 의해 주로 일어남이 관찰되었다.

• 대한수학회지
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• 제53권1호
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• pp.73-88
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• 2016

We consider ${\mathcal{T}}_{\infty}(F)$ - the space of all innite upper triangular matrices over a eld F. We give a description of all linear maps that satisfy the property: if rank(x) = 1, then $rank({\phi}(x))=1$ for all $x{\in}{\mathcal{T}}_{\infty}(F)$. Moreover, we characterize all injective linear maps on ${\mathcal{T}}_{\infty}(F)$ such that if rank(x) = k, then $rank({\phi}(x))=k$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.527-530
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• 2001

In this paper, the basic characteristics of flat fluorescent lamp using ultraviolet generate from gas discharge and powder type electrolyminescent display(P-ELD) using a phenomenon of the light emission eaused by the electrical field applied to phosphor are studied. The lamp is a simple structure with insulator layer, phosphor layer, and gas gap. Current(displacement current + discharge current) in flat fluorescent lamp using.

• Korean Journal of Mathematics
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• 제24권3호
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• pp.319-330
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• 2016

The manifold $^*g-ESX_n$ is a generalized n-dimensional Riemannian manifold on which the differential geometric structure is imposed by the unied eld tensor $^*g^{{\lambda}{\nu}}$ through the ES-connection which is both Einstein and semi-symmetric. The purpose of the present paper is to study the algebraic geometric structures of 5-dimensional $^*g-ESX_5$. Particularly, in 5-dimensional $^*g-ESX_5$, we derive a new set of powerful recurrence relations in the first class.