• 제목/요약/키워드: method of research

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Analytical Method of additive in Polyester (I) (폴리에스테르의 첨가제 분석법(I))

  • Jung, Jong Hwa;Lee, Kyeong Hee
    • Analytical Science and Technology
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    • v.12 no.1
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    • pp.84-88
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    • 1999
  • A method to analyze additives in a polyester resin has been studied by utilizing a centrifuge and a thin layer chromatography. Identification of the separated organic and inorganic compounds were carried out by spectrophotometers, such as NMR, UV-VIS, IR and XRD. For the polyester resin studied in this research contained organic and inorganic compounds which were found to be a dimer form of 2-phenylbenzoazole and an anatase form of $TiO_2$, respectively.

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A Novel Digital Driving Method for AM-OLED

  • Lee, Seung-Woo;Choi, Jae-Won;Jang, Jin;Chung, Hoon-Ju
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.837-840
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    • 2007
  • We propose a novel digital driving method for AM-OLED (Active Matrix-Organic Light Emitting Diode) display. Proposed method modulates $V_{DD}$ so that luminance may be weighted in accordance with the bit significance. We can increase the minimum emission time or slower scan circuits are applicable by using proposed method.

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S/W Based Frame-Level Synchronization for Irregular Screen Processing System

  • Shin, IlHong;Lee, Seonghee;Lee, Eunjun;Lee, Nam Kyung;Lee, Hyunwoo
    • ETRI Journal
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    • v.38 no.5
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    • pp.868-878
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    • 2016
  • A multi-screen environment provides a new opportunity for digital signage applications, where various irregularly shaped screens are employed as an effective means for advertisements and information. A formation method applicable to numerous irregularly shaped screens is proposed to provide a new perspective on digital signage applications. The crucial part of the proposed method comes from the geometric sensing of each screen and the formation of a virtual screen where geometrically aligned content extraction and encoding are employed for content transmission to each screen. In addition, a software-based synchronization method for the proposed system is proposed to address the frame-level synchronization between screens. The experimental results of the proposed method show an improved performance of the frame-level synchronization, where the inconsistency between frames is not identified.

Influence of Extraction Method on Quality and Functionality of Broccoli Juice

  • Lee, Sung Gyu;Kim, Jin-Hee;Son, Min-Jung;Lee, Eun-Ju;Park, Woo-Dong;Kim, Jong-Boo;Lee, Sam-Pin;Lee, In-Seon
    • Preventive Nutrition and Food Science
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    • v.18 no.2
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    • pp.133-138
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    • 2013
  • This study was performed to compare the quality and functionality of broccoli juice as affected by extraction method. Broccoli juice was extracted using method I (NUC Kuvings silent juicer), method II (NUC centrifugal juicer), and method III (NUC mixer), and the quality properties of the broccoli juices were analyzed using three different methods. Additionally, the antioxidative, anticancer, and anti-hyperglycemic activities of broccoli juice prepared by the three different methods were investigated in vitro. The broccoli juice made by method I contained the highest polyphenol and flavonoid contents at 1,226.24 mg/L and 1,018.32 mg/L, respectively. Particularly, broccoli juice prepared by method I showed higher DPPH and ABTS radical scavenging activities than those of the other samples. Additionally, broccoli juice made by method I showed the highest growth inhibitory effects against HeLa, A549, AGS, and HT-29 cancer cells. Broccoli juice prepared by method I had the highest ${\alpha}$-glucosidase inhibitory effects. These results indicate that there are important differences in chemical and functional qualities between juice extraction techniques.

Probabilistic Bilinear Transformation Space-Based Joint Maximum A Posteriori Adaptation

  • Song, Hwa Jeon;Lee, Yunkeun;Kim, Hyung Soon
    • ETRI Journal
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    • v.34 no.5
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    • pp.783-786
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    • 2012
  • This letter proposes a more advanced joint maximum a posteriori (MAP) adaptation using a prior model based on a probabilistic scheme utilizing the bilinear transformation (BIT) concept. The proposed method not only has scalable parameters but is also based on a single prior distribution without the heuristic parameters of the previous joint BIT-MAP method. Experiment results, irrespective of the amount of adaptation data, show that the proposed method leads to a consistent improvement over the previous method.

A Basic Study on the Development of a Mobile Data Sampling Method based on ESM to Examine Child-care Teachers' Emotional Experience (ESM기반 보육교사 정서 연구를 위한 데이터 표집기술 개발에 관한 기초연구)

  • Kim, Soojung;Lee, Yungil
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.7 no.6
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    • pp.199-206
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    • 2017
  • The experience sampling method (ESM) is an innovative research method to study the immediate real emotional experience experienced in real life through the immediate reaction of research participants. ESM, which has received significant attention in recent, is considered as the research method particularly for child care teachers' emotions and happiness. This method has been shown to be able to overcome the limitations in current research methods, based on teachers' recall or surveys, in assessing child care teachers' emotional states or stress levels. Despite the expectation that the need for further research on the increased stress and negative emotional experiences of child care teachers and its appropriateness as the alternative research method to study child care teachers' immediate emotional experience, ESM has deficiencies in that research participants need to have their pencil-and-paper survey packages on hand whenever their electronic beepers randomly beep. Furthermore, ESM demands much more researcher energy and efforts to handle the voluminous data collected from each participant in effectively creating a database. In this paper, in order to apply ESM successfully to the study of child care teachers' emotional experience, we aim to develop a software program that uses mobile communication technology. Given that traditional types of data collection methods in social science research can prove too burdensome to encourage participation in surveys in the first place or ensure the return of completed surveys, the present study adopts a convergent research approach to develop a software program that is able to obtain ESM participants' answers immediately on their personal smart phones. This study deals with system construction and prototyping for software development as a basic research and evaluates the research results through indepth interview with experts.

Comparison and Analysis of Return Current Measurement Values on High Speed Line (고속선 귀선전류 측정값 비교 및 분석)

  • Kim, Yong-Kyu;Kim, Ju-Yeop;Oh, Seh-Chan;Baek, Jong-Hyun;Yoon, Yong-Ki;Kwak, Woo-Hyun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.5
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    • pp.877-884
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    • 2017
  • A method of common earth, which is proposed by French Railway(SNCF) and is applied to high speed railway, minimizes the effect of the traction return current from tracks so that trackside electric devices can be protected and operation and maintenance staffs are kept out from injury in an electric railway environment. According to it, all the new domestic electric railway lines are replaced from existing individual earth method to the common earth method. In this paper, we analyze the correlation between common earth method and traction return current to prove whether the common earth has surely contributed to minimize the effect of the traction return current. The analysis was done based on the measurement of the traction return current at the domestic high speed railway line.

Determination of J-Resistance Curves of Nuclear Structural Materials by Iteration Method

  • Byun, Thak-Sang;Bong Sang lee;Yoon, Ji-Hyun;Kuk, Il-Hiun;Hong, Jun-Hwa
    • Proceedings of the Korean Nuclear Society Conference
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    • 1998.05b
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    • pp.336-343
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    • 1998
  • An iteration method has been developed for determining crack growth and fracture resistance cure (J-R curve) from the load versus load-line displacement record only. In this method, the hardening curve, the load versus displacement curve at a given crack length, is assumed to be a power-law function, where the exponent varies with the crack length. The exponent is determined by an iterative calculation method with the assumption that the exponent varies linearly with the load-line displacement. The proposed method was applied to the static J-R tests using compact tension(CT) specimens, a three-point bend (TPB) specimen, and a cracked round bar (CRB) specimen as well as it was applied to the quasi-dynamic J-R tests using CT specimens. The J-R curves determined by the proposed method were compared with those obtained by the conventional testing methodologies. The results showed that the J-R curves could be determined directly by the proposed iteration method with sufficient accuracy in the specimens from SA508, SA533, and SA516 pressure vessel steels and SA312 Type 347 stainless steel.

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Speckle noise reduction in SAR images using an adaptive wavelet Shrinkage method

  • Kim, Kwang-Yong;Jeong, Soo;Kim, Kyung-Ok
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.303-307
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    • 2002
  • Although Synthetic Aperture Radar(SAR) is a very powerful and attractive tool, automatic interpretation of SAR images is extremely difficult because of several reason. Spatially, speckle noise reduction in SAR images is important step to interpret the SAR image at the preprocessing step. The speckle noise in SAR images is modeled to be multiplicative, and therefore, a signal-dependent noise. So, it has deflated many image-denoising algorithms that are based on additive noise model. In this paper, we propose an adaptive wavelet shrinkage method for speckle noise reduction in SAR images by analyzing the high frequency level in detail. We first decompose minutely the high frequency level to analyze the noise level. And then, we determine the weighting threshold value per the level, and layer. Finally, using those weighting threshold, we produce the efficient wavelet shrinkage method. So, this method not only reduces the speckle noise, but also preserves image detail and sharpness.

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Novel islanding detection method for grid connected PV system (계통연계형 태양광발전시스템의 새로운 단독운전 검출기법)

  • Jung, Young-Seok;So, Jung-Hun;Yu, Byung-Gyu;Yu, Gwon-Jong;Choi, Jae-Ho
    • Proceedings of the KIEE Conference
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    • 2005.07b
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    • pp.1705-1707
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    • 2005
  • This paper proposes a novel active frequency drift(AFD) method for the islanding prevention of grid-connected photovoltaic inverter. To detect the islanding phenomenon of grid-connected photovoltaic(PV) inverters concerning about the safety hazards and the damage to other electric equipments, many kinds of anti-islanding methods have been presented. Among them, AFD method using chopping fraction(cf) enables the islanding detection to drift up(or down) the frequency of the voltage during the islanding situation. However, the performance of the conventional AFD methods, which have a certain value of cf only, is inefficient and difficult to design the appropriate cf value analytically to meet the limit of harmonics. In this paper, the periodic chopping fraction based on an AFD method is proposed. This proposed method shows the analytical design value of cf to meet the test procedure of IEEE Std. 929-2000 with the power quality and islanding detection time. To verify the validation of the proposed method, the islanding test results are presented. It is confirmed that the proposed method has not only less harmonic distortion but also good performance of islanding detection compare with the conventional AFD method.

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