• Journal of the Optical Society of Korea
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• v.13 no.1
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• pp.92-97
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• 2009

In this paper, a conventional simulated annealing (SA) method for optimization of a kinoform computer generated hologram (CGH) is analyzed and the SA method is modified to reduce a reconstruction error rate (ER) of the CGH. The dependences of the quantization level of the hologram pattern and the size of the data on the ER are analyzed. To overcome saturation of the ER, the conventional SA method is modified as it magnifies a Fourier-transformed pattern in the intermediate step. The proposed method can achieve a small ER less than 1%, which is impossible in the conventional SA method.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2451-2454
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• 2013

Poly(methyl methacrylate) coated $BaF_2:Er^{3+}$ nanoparticles were prepared via a novel reverse-emulsion polymerization process using methyl methacrylate as continuous phase and water as dispersed phase. Preparation and coating of $BaF_2:Er^{3+}$ particles were processed in a single step. The resulting polymeric composites show the characteristic $Er^{3+}$ luminescence at excitation of 980 nm and may have potential applications in amplified optical networks.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.90-93
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• 1997

고주파 반응성 스퍼터링 방법을 사용하여 희토류가 첨가된 SiO$_2$ 박막을 제작하여 특성을 조사하여, 양질의 희토류 원소가 첨가된 SiO$_2$ 박막의 최적의 제작조건을 도출하고 Er-Al:SiO$_2$ 박막의 소자웅용 가능성에 대하여 조사하였다 열처리전의 Er의 농도는 EDS(Energy dispersing x-ray spectrometer)로 측정한 결과 0.77% 로 농도를 나타내었고 코아층 첨가된 Er은 균일하게 분포되었다 크레드층의 굴절률은 633nm의 파장에서 측정하였을때 1.458이였고 코아층의 굴절률은 동일 파장에서 1.757이였다. 굴절률 분포도 (Refractive Index Profile)는 계단형 굴절률 분포로 코아층/클래드 굴절률 차 $\Delta$n$_{ESI}$ = 0.1였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.4
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• pp.745-750
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• 2000

In ATM Network, many algorithms have been proposed for rate-based ABR flow control. The object of these Algorithms is to turn around from cell loss and to use the unused bandwidth by ABR Traffic. These Algorithms are applied to control ABR Traffic by EFCI and ER switches. In previous paper, we showed the using rate of bandwidth for the characteristic of each algorithm applied these algorithm network. In this paper, we will do that to apply these algorithms to a network and to make a graph of characteristic of each algorithm.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.10a
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• pp.243-247
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• 1996

This paper presents a vibration control of a flexible structure using a controllable ER fluid damper. A clamped-clamped flexible structure system supported by two short columns mimicking a small-sized bridge system is considered. An ER fluid damper which is operated in shear mode is designed and attached to the middle of the flexible structure. The governing equation of motion and associated boundary conditions are derived from Hamilton's principle. A sliding mode control is formulated in order to actively suppress the vibration of the structure due to external excitations. Experimental control results are presented in the frequency domain.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.256-261
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• 2000

Electro-Rheological(ER) fluid is applied to a controllable squeeze film damper(SFD) for stabilizing a flexible rotor system. ER fluid is a class of functional fluid whose yield stress varies according to the applied electric field strength, which is observed as viscosity variation of the fluid. In applying ER fluid to a SFD, a pair of rings of the damper can be used as electrodes. When the electrodes are divided into a horizontal pair and a vertical one, the SFD can produce damping force in each direction independently. A prototype of the directionally controllable SFD was constructed and its performance was experimentally and numerically investigated in the present work.

• The Journal of Internal Korean Medicine
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• v.39 no.6
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• pp.1281-1289
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• 2018

Objectives: This study is the first report on a case of subclinical hypothyroidism treated with Modified Er-Xian Decoction, which is rarely used in Korea. Methods: Patients were treated for 3 months with Modified Er-Xian Decoction and their therapeutic effects were evaluated through thyroid function tests and Spleen-Kidney deficiency Questionnaire. Results: Initial improvement was apparent after the administration of Modified Er-Xian Decoction. After 3 months of treatment, the patient 's Spleen-Kidney deficiency index improved significantly, and thyroid hormone levels returned to normal. Conclusions: In this case report, symptoms and biochemical improvement were confirmed based on a single herbal medicine prescription for subclinical hypothyroidism. It is necessary to verify the effect of this prescription through well - established clinical trials.

• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.236-243
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• 2018

A series of $Er^{3+}/Yb^{3+}$ co-doped fluorophosphate glasses with varying $YbF_3$ concentration were prepared by a high temperature melt quenching technique. Absorption and emission cross-sections were determined by using the McCumber theory. The larger emission cross-section ($9.86{\times}10^{-21}cm^2$) and longer fluorescence lifetime (12.37 ms) were obtained for the $^4I_{13/2}{\rightarrow}^4I_{15/2}$ transition of ABS3Er4Yb glass. The sensitivity and temperature of the maximum sensitivity were evaluated by the fluorescence intensity ratio method from the measured upconversion spectra. The results were discussed and compared to the other reported glasses.

• Journal of Gastric Cancer
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• v.20 no.4
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• pp.345-354
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• 2020

Early detection of gastric cancer is crucial because the survival rate can be improved through curative treatment. Although surgery and gastrectomy with lymph node dissection remain as the gold standard for curative treatment, early gastric cancer (EGC) with negligible risk of lymph node metastasis can be treated with endoscopic resection (ER), such as endoscopic submucosal dissection. Among gastric cancers, undifferentiated-type cancer is distinguished from differentiated-type cancer in various aspects in terms of clinical features and pathophysiology. The undifferentiated-type cancer is also known to be associated with an aggressive behavior and a poor prognosis. Therefore, the indication of ER for undifferentiated EGC is limited compared with differentiated-type. Recent studies have reported that ER for undifferentiated EGC is safe and shows favorable short- and long-term outcomes. However, it is necessary to understand the details of the research results and to selectively accept them. In this review, we aimed to evaluate the current practice guidelines and the short-term and long-term outcomes of ER for undifferentiated type EGC.

• Proceedings of the Optical Society of Korea Conference
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• 2001.08a
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• pp.246-247
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• 2001

Undoped YCa$_4$O(BO$_3$)$_3$ (sp. gr. Cm) single crystals as well as singly or co-doped with Yb, Er and Ce were grown using Czochralski technique. With the aid of x-ray analysis, crystallographic data of Ce, Er, Yb:YCA$_4$O(BO$_3$) crystals were found.