• Title/Summary/Keyword: 김대성

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Preparation and Physical Properties of Bio-Composites Using Kenaf Cultivated in Korea (국내 재배 케나프 섬유를 이용한 바이오복합재의 제조와 물리적 특성)

  • Kim, Dae-Sung;Song, Kyung-Hun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.34 no.11
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    • pp.1889-1899
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    • 2010
  • This study examines the preparation and characterization of Kenaf/Starch bio-composites used as filler and a matrix. Kenaf was cultivated in Chung-ju in Korea, and the Kenaf/Starch bio-composites were prepared under various conditions of kenaf fiber length (1-5 centimeters); the content of Kenaf fiber was 10%, 20%, 30%, and 40%, and the number of composite layers (one-four). Depending on the formation conditions of Kenaf/Starch composites, the physical properties such as tensile strength, elongation, and the young modulus of the Kenaf/Starch composites were measured. In addition, we measured the SEM cross-section images in order to investigate the interfacial adhesion properties of fractured surfaces. As a result, the tensile strength and elongation of the Kenaf/Starch composites were highest in the molding conditions of a hot press at $120^{\circ}C$, 3000PSI of pressure, and for 30 minute periods. The result of measuring the physical properties of the composites manufactured by varying the content of Kenaf fiber when the content of Kenaf fiber was 30% as well the physical properties of the Kenaf/Starch composite was found desirable. It was found that the physical properties improved with more overlapped layers in the composites manufactured by varying the number of overlapped layers. Through the measuring of the SEM cross-section images, we found that the interfacial adhesion state between the filler and matrix of Kenaf/Starch composite greatly affects the physical properties.

Relative Radiometric Normalization of Hyperion Hyperspectral Images Through Automatic Extraction of Pseudo-Invariant Features for Change Detection (자동 PIF 추출을 통한 Hyperion 초분광영상의 상대 방사정규화 - 변화탐지를 목적으로)

  • Kim, Dae-Sung;Kim, Yong-Il
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.26 no.2
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    • pp.129-137
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    • 2008
  • This study focuses on the radiometric normalization, which is one of the pre-processing steps to apply the change detection technique fur hyperspectral images. The PIFs which had radiometric consistency under the time interval were automatically extracted by applying spectral angle, and used as sample pixels for linear regression of the radiometric normalization. We also dealt with the problem about the number of PIFs for linear regression with iteratively quantitative methods. The results were assessed in comparison with image regression, histogram matching, and FLAASH. In conclusion, we show that linear regression method with PIFs can carry out the efficient result for radiometric normalization.

Unsupervised Change Detection of Hyperspectral images Using Range Average and Maximum Distance Methods (구간평균 기법과 직선으로부터의 최대거리를 이용한 초분광영상의 무감독변화탐지)

  • Kim, Dae-Sung;Kim, Yong-Il;Pyeon, Mu-Wook
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.29 no.1
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    • pp.71-80
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    • 2011
  • Thresholding is important step for detecting binary change/non-change information in the unsupervised change detection. This study proposes new unsupervised change detection method using Hyperion hyperspectral images, which are expected with data increased demand. A graph is drawn with applying the range average method for the result value through pixel-based similarity measurement, and thresholding value is decided at the maximum distance point from a straight line. The proposed method is assessed in comparison with expectation-maximization algorithm, coner method, Otsu's method using synthetic images and Hyperion hyperspectral images. Throughout the results, we validated that the proposed method can be applied simply and had similar or better performance than the other methods.

Automatic Registration between Multiple IR Images Using Simple Pre-processing Method and Modified Local Features Extraction Algorithm (단순 전처리 방법과 수정된 지역적 피쳐 추출기법을 이용한 다중 적외선영상 자동 기하보정)

  • Kim, Dae Sung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.6
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    • pp.485-494
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    • 2017
  • This study focuses on automatic image registration between multiple IR images using simple preprocessing method and modified local feature extraction algorithm. The input images were preprocessed by using the median and absolute value after histogram equalization, and it could be effectively applied to reduce the brightness difference value between images by applying the similarity of extracted features to the concept of angle instead of distance. The results were evaluated using visual and inverse RMSE methods. The features that could not be achieved by the existing local feature extraction technique showed high image matching reliability and application convenience. It is expected that this method can be used as one of the automatic registration methods between multi-sensor images under specific conditions.

Ameliorating Effects of HPM-1 on Scopolamine-induced Memory Impairments in Mice (몰약 당귀 오미자 혼합제제 HPM-1의 Scopolamine에 의해 유도된 기억력 감퇴에 대한 개선 효과)

  • Ahn, Jeewoon;Kim, Dae-Sung;Cho, Hyoung-Kwon;Kim, Youn-Chul;Kim, Sung Yeon;Oh, Hyuncheol;Seo, Jungwon
    • Korean Journal of Pharmacognosy
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    • v.46 no.3
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    • pp.243-249
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    • 2015
  • Myrrh, Angelicae Radix, and Schisandrae Fructus have been used to treat diverse diseases including neurological disorder in the traditional Korean medicine. In the present study, we investigated the ameliorating effects of HPM-1, a combined extract of Myrrh, Angelicae Radix and Schisandrae Fructus, on scopolamine-induced memory impairments in mice. First, we assessed HPM-1, HPM-2 and HPM-3, in which Myrrh was extracted with water, 30% ethanol, and 30% ethanol/3% vinegar, respectively. The oral administration of HPM-1, HPM-2, or HPM-3 significantly reversed scopolamine-induced reduction of spontaneous alternation in the Y-maze task. In the passive avoidance task, HPM-1 or HPM-3 restored the decreased latency time of the retention trial by scopolamine treatment, but in terms of efficacy, HPM-1 showed more beneficial effects than HPM-3. In addition, HPM-1 administration reversed scopolamine-induced reduction of spontaneous alternation in the Y-maze task and scopolamine-decreased latency time in the passive avoidance in a dose-dependent manner. These results suggest that HPM-1 has the therapeutic potential in memory impairments.

Whitening Effect and Mechanism of Aerial Part of Pueraria lobata (갈만 추출물의 미백활성 및 기전 연구)

  • Kim, Da Eun;Hwang, Yeon Sil;Chang, Bo Yoon;Han, Ji Hye;Kim, Dae Sung;Kim, Hye Soo;Cho, Hyoung Kwon;Kim, Sung Yeon
    • Korean Journal of Pharmacognosy
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    • v.47 no.4
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    • pp.343-351
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    • 2016
  • The purpose of this study was to evaluate the whitening effect of aerial part of Pueraria lobata and mechanisms. Aerial part of Pueraria lobata, dose-dependently reduced the melanin content. Aerial part of Pueraria lobata, significantly decreased cellular tyrosinase activity, while there was not any effect on tyrosinase in cell-free conditions. To elucidate the mechanisms behind the aerial part of Pueraria lobata, treated melanogenesis regulation, the expressions of melanogensis related genes, proteins, and the activity of ${\alpha}-glucosidase$ were determined. Aerial part of Pueraria lobata, significantly inhibited gene and protein levels of MITF, tyrosinase and TRP-1. It suppressed the ${\alpha}-glucosidase$, leading to inhibition on the maturation of tyrosinase. Also aerial part of Pueraria lobata, was observed to have the high antioxidant activity. These results suggested that whitening effect of aerial part of Pueraria lobata, should be due to the down-regulation of MITF, tyrosinase and TRP-1 expression and the intercepting maturation of tyrosinase through suppressing ${\alpha}-glucosidase$. Another should be the high anti-oxidant activity. The findings show the possibility that aerial part of Pueraria lobata, can be used as a potential skin-whitening agent.

Optimal Design and Process Parameters of Biological Nutrent Removal Processes using Activated Sludge Model No.2d (ASM No. 2d를 이용한 생물학적 질소, 인 제거 공정의 최적 설계 및 운전인자 고찰)

  • Ahn, Ho-Chul;Park, Myung-Gyun;Yoo, Hee-Chan;Kim, Dae-Sung;Ahn, Won-Sik;Heo, Yong-Rok
    • Proceedings of the Korea Water Resources Association Conference
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    • 2006.05a
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    • pp.1400-1404
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    • 2006
  • 생물학적 질소, 인 제거 공정(이하 BNR)의 운전에 있어서 최적 유입수의 C/N(COD/TKN)비, SRT 및 온도의 범위 및 정량적 수치 등은 유기물 뿐 만아니라 질소, 인의 처리 효율에 있어서 매우 중요하다. 특히, 외국과 다른 저농도 유기물 특성을 보이는 국내 하수에 대해서는 BNR 공정의 선택과 설계 및 운전인자의 선별이 무엇보다도 중요한 역할을 한다. 본 연구에서는 IAWQ에서 제시한 ASM No.2d를 기초로 하여 만들어진 전산모형인 Envirosim사의 Biowin 프로그램을 시뮬레이션 도구로 활용하여, 국내 하수에 비교적 적용하기 용이한 A2/O 공정과 MUCT 공정에 대한 유기물, 질소 및 인처리 효율을 비교하고 유입수의 C/N와 SRT 및 온도에 따른 질소, 인 처리 특성과 유출수의 거동 등을 파악하였다. 시뮬레이션 결과, 국내 하수에서는 A2/O 보다는 MUCT 공정이 질소, 인 처리효율이 더 크게 나타났다. 온도와 SRT가 일정한 상태에서 C/N비는 7이상에서 TKN과 TP제거효율이 양호하게 나타났고, 온도와 C/N비를 일정한 조건에서는 SRT가 7일을 넘어서면 효율이 급격히 낮아지는 현상을 관찰할 수 있었다. 온도조건 실험에서는 $20^{\circ}C$이하, 특히 국내 하수처리장에 BNR 적용시 설게조건인 $13^{\circ}C$에 근접해서는 TKN의 제거효율은 급격히 떨어지는 반면에 인 제거효율이 상승하는 것으로 나타났다.

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Comparison of various methods to obtain structural vibration for vibro-acoustic noise (구조 방사 소음의 해석을 위한 구조물의 진동 획득 방법의 비교)

  • Wang Se-Myung;Shin Min-Cheol;Koo Kun-Mo;Kim Dae-Sung;Bae Won-Ki;Kyong Yong-Soo;Kim Jung-Seon;Kook Jung-Hwan;Thuy Tran ho Vihn
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.607-611
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    • 2006
  • There are several methods to obtain structural vibration for analysis of vibro-acoustic noise. First of all, vibration data can be obtained through the structural analysis using finite element method. Although this method has no need to experiment, the analysis result is unreliable when the structure and the vibration source is complex to model exactly. The second method is to measure vibration using a number of sensors. The analyzed vibro-acoustic noise with directly measured data is setting morereliable when the number of data acquisition points is getting larger. However, it requires large amount of time and effort to measure all vibration data on every node especially when the size of vibrating structure is large. The Modal Expansion Method(MEM), which uses mode information and measurement data, has been introduced to compensate their limits. With a relatively small number of measurement data, the reliable structural vibration for vibro-acoustic noise can be obtained using this semi-analysis method. Although MEM gives reliable result, it is restricted by the number of modes and measurement points. In this paper, structural analysis, direct vibration measurement method and MEM are compared using the simple aluminum box model. Furthermore, the washing machine case is also provided as a comparative example. The Laser Doppler Vibrometer(LDV) was used instead of contact type accelerometer to get vibration data.

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Effect of Fructus Ligustri Lucidi $H_2O$ Extract on Cell Proliferation in Hman Dermal Fibroblast (여정실 물 분획물이 인체 진피 섬유아세포의 증식에 미치는 영향)

  • Lim, Nan-Young;Kim, Dae-Sung;Ko, Kyung-Sook;Mun, Yeun-Ja;Woo, Won-Hong
    • Korean Journal of Acupuncture
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    • v.28 no.3
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    • pp.43-51
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    • 2011
  • Objectives : In this study, we investigated the effect of Fructus Ligustri Lucidi $H_2O$ fraction (FLLW) on cell proliferation, and the phosphorylation of ERKs and Akt in human dermal fibroblast neonatal (HDFn). Methods : After treatment of HDFn with FLLW, MTT assay was performed to quantitatively determine cellular viability. The ERK and Akt pathways were analyzed in vitro by Western blot in a HDFn. HDFn proliferation after FLLW and minoxidil treatment in the absence or presence of PD98059, a MEK inhibitor, LY294002, and a PI3K inhibitor, was examined by Western blot or MTT assay. Results : FLLW increased cell proliferation in a dose-dependent manner and minoxidil used as positive control also induced cell proliferation in HDFn. FLLW increased the phosphorylation of ERK and Akt. In addition, minoxidil, too, induced the phosphorylation of ERK and Akt in HDFn. PD98059 and LY294002 significantly attenuated FLLW-inducible p-ERK and p-Akt expression and proliferation in cultured HDFn. Conclusions : Our results suggest that FLLW stimulates the growth of fibroblast cells through ERK and Akt pathways. Therefore, FLLW is a potential agent for the inducer of fibroblast growth.

Development and Performance Evaluation of a Liquid Particle Generator (액적 발생 장치 개발 및 성능 평가)

  • Heo, Jung-Hyuk;Kim, Dae-Seong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.9
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    • pp.4334-4340
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    • 2012
  • In this work, we developed and evaluated the Liquid Particle Generator for generating fine particles in the air. The Liquid Particle Generator, which was based on the spray-evaporation method, had two kinds of orifices: 0.3 mm and 0.5 mm. The Liquid Particle Generator was operated at different pressure between 1 bar and 4 bars to find relationship between input pressure and droplet output rate. In addition, the size distribution of the droplets generated by the Liquid Particle Generator with different orifices was measured by the SMPS system and the optical particle counter. As a result, it was shown that the Liquid Particle Generator with 0.3 mm orifice generated droplets of around 0.3 ${\mu}m$ and atomized particles very stably. The Liquid Particle Generator having 0.5 mm orifice generated bigger droplets, compared with the Liquid Particle Generator with 0.3 mm orifice. Additionally, in these Liquid Particle Generators (0.3 mm and 0.5 mm orifice), little coagulation of particles did occur because of fine droplets atomized by the jet. Therefore, the Liquid Particle Generator could be used as an aerosol generator for atomizing fine particles.