• Title/Summary/Keyword: 박정현

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Disease Detection Algorithm Based on Image Processing of Crops Leaf (잎사귀 영상처리기반 질병 감지 알고리즘)

  • Park, Jeong-Hyeon;Lee, Sung-Keun;Koh, Jin-Gwang
    • The Journal of Bigdata
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    • v.1 no.1
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    • pp.19-22
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    • 2016
  • Many Studies have been actively conducted on the early diagnosis of the crop pest utilizing IT technology. The purpose of the paper is to discuss on the image processing method capable of detecting the crop leaf pest prematurely by analyzing the image of the leaf received from the camera sensor. This paper proposes an algorithm of diagnosing leaf infection by utilizing an improved K means clustering method. Leaf infection grouping test showed that the proposed algorithm illustrated a better performance in the qualitative evaluation.

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A Study on Virtual Community Consumers′ Information Behavior and Consumer Satisfaction -Focused on Internet Community- (가상공동체에서의 소비자 정보활동과 소비자만족 연구 -인터넷 동호회를 중심으로-)

  • 박정현;이기춘
    • Journal of Families and Better Life
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    • v.20 no.1
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    • pp.139-149
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    • 2002
  • The aim of this study is to examine the consumer information behavior and consumer satisfaction in virtual community, and analyse influential variables on these. The data for this study were collected from members of virtual community for cosmetics in DAUM ( www.daum.net) through self-report questionnaires. Main findings are following; Virtual community consumer experiences satisfaction for products including information, and information behavior. And the greater information behaviors are associated with the greater satisfaction. And the virtual community consumers' information behavior and satisfaction don't differ largely by internet variables and socio-demographic variables. On the other hand, virtual community consumers' information behavior and satisfaction are associated with psychological variables like community membership, information wants, enduring involvements. In conclusion, these satisfactions make the effect of ‘feedback’ to information behavior, so these virtual community is able to be activated. And this also means that virtual community is Ideal space for consumer to expand information behavior.

An Automatic Control System of a Camera Zoom and Focus Using the Fuzzy Inference and the Difference of the Light and Darkness (Fuzzy 추론 및 명암차이법을 이용한 카메라 줌, 포커스 자동 조절 시스템)

  • 박홍선;박상욱;박정현;곽주원;손영선
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2002.12a
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    • pp.406-409
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    • 2002
  • 본 논문에서는 문자인식이 가능하도록 줌, 포커스를 제어하여 한글 문서 영상을 확대/축소하는 시스템을 구현하였다. 한글 문서 영상에서 확대/축소 할 영역이 지정되면 그 영역의 가로, 세로 거리를 펄스 수로 변환한 후 Step모터를 제어하여 그 위치만큼 카메라를 이동시킨다. 문서 영상이 입력되면 문자인식이 가능한 크기만큼 줌을 제어하고, 피드백 되어진 영상으로부터 조정된 줌에 맞는 포커스로 근접 제어한 후, 더욱 선명한 영상을 얻기 위해 명암 차이에 의한 미세 조정을 하였다. 이 경우, 줌 및 포커스는 퍼지 추론으로 .제어하는 DC모터로 조정하였다.

A Study on the Microstructural Control of LAS Ceramics (III) : Influence of Li2O.4B2O3 Frit Addition on the Microstructure and Thermal Expansion of $\beta$-Spodumene made from Kaolinite (LAS계 내열충격성 재료의 미세구조 제어(III): Li2O.4B2O3 첨가가 카올린을 공급원으로하여 합성한 $\beta$-Spodumene의 미세구조 및 열팽창특성에 미치는 영향)

  • 박정현;김현민;이화선
    • Journal of the Korean Ceramic Society
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    • v.29 no.8
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    • pp.646-650
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    • 1992
  • Effect of Li2O.4B2O3 frit addition on microstructural and thermal expansion behaviour of the $\beta$-spodumene ceramics made from kaolinite was investigated. With 2.0~4.0 wt% frit addition, the densification by liquid phase sintering caused low water absorption below 3% and enhancement of beding strength. As the amount of frit addition was increased, thermal expansion coefficient was increased to large scale, but in 2 wt% frit addition, its thermal expansion coefficient was constrained to 1.92$\times$10-6$^{\circ}C$-1.

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The Influence of CuO on Bonding Behaviors of Low-Firing-Substrate and Cu Conductor (저온소성 기판과 Cu와의 동시소성에 미치는 CuO의 첨가효과)

  • 박정현;이상진
    • Journal of the Korean Ceramic Society
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    • v.31 no.4
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    • pp.381-388
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    • 1994
  • A new process which co-fires the low-firing-substrate and copper conductor was studied to achieve good bond strength and low sheet resistance of conductor. Cupric oxide is used as the precursor of conductive material in the new method and the firing atmosphere of the new process is changed sequently in air H2N2. The addition of cupric oxide and variations of firing atmosphere permited complete binder-burnout in comparison with the conventional method and contributed to the improvement of resistance and bonding behaviors. The potimum conditions of this experiment to obtain the satisfactory resistance and bond strength are as follows (binder-burnout temperature in air; 55$0^{\circ}C$, reducing temperature in H2; 40$0^{\circ}C$ for 30 min, ratio of copper and cupric oxide; 60:40~30:70 wt%). The bonding mechanism between the substrate and metal was explained by metal diffusion layer in the interface and the bond strength mainly depended on the stress caused by the difference of shrinkage and thermal expansion coefficient between the substrate and metal.

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The Effect of Frit on Bonding Behavior of Low-firing-substate and Cu Conductor (프릿트 첨가에 따른 저온소성 기판과 Cu와의 접합 거동에 관한 연구)

  • 박정현;이상진
    • Journal of the Korean Ceramic Society
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    • v.32 no.5
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    • pp.601-607
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    • 1995
  • The bond strength between the low-firing-substrate and Cu conductor depended on the softening point and the amount of frit added to the metal paste. The addition of 3 wt% frit (softening point: 68$0^{\circ}C$) to the metal paste resulted in the improvement of bond strength, which was approximately 3 times higher (3kg/$\textrm{mm}^2$) than that of non frit condition. It was also found that fracture surface shifted to the ceramic substrate in the interface region. These phenomena were attributed to the frit migration into the metal-ceramic interface. It was thought that the migration of glass frit occurred extensively when the softening point of glass firt was 68$0^{\circ}C$. The sheet resistance of Cu conductor remained constant by the addition of 4 wt% frit regardless of softening point of frit. For all samples with more than 4 wt% frit, the sheet resistance increased abruptly.

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The Effect of Al Powder as an Additive on the Sintering of $Al2_O_3$ (I. In air, $1350~1550^{\cire}C$) (첨가된 알루미늄 분말의 산화가 알루미나 소결에 미치는 영향(I. 공기중, $1350~1550^{\cire}C$에서))

  • 박정현;안주삼;김해두
    • Journal of the Korean Ceramic Society
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    • v.20 no.1
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    • pp.49-54
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    • 1983
  • The main object of this study is to investigate the effect of Al powder as an additive on the sintering of calcined alumina comparing with that of calcined alumina alone. The degree of Al oxidation is calculated by measuring the weight increase during the firing Water absorption bulk density and compressive strength of the $Al_2O_3+Al$ system at each temperature are compared with those of $Al_2O_4$ alone. The $Al_2O_3+Al$ system shows better physical propeties than Al2O3 alone and it seems by the SEM observation that the fine oxidized Al particles(fine $Al_2O_3$ particles submicron unit) fill the interstices of the original $Al_2O_3$ par-ticles and thus result in the well-close-packed arrangement of the particles.

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Synthesis of NiO-doped Al2O3 Powder by Spray Pyrolysis (분무열분해법에 의한 NiO 첨가 Al2O3 분체의 합성)

  • 박정현;조경식;김한태
    • Journal of the Korean Ceramic Society
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    • v.28 no.8
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    • pp.593-602
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    • 1991
  • Al2O3 and NiO-doped Al2O3 powders were prepared from the ethanol solution of Al (NO3)3$.$9H2O and Ni(NO3)2$.$6H2O by spray pylolysis method using two-fluid nozzle. As a result of spraying test with 0.3 mol/{{{{ iota }} concentration starting solution, mean droplet sizes varied with 8.99∼9.69$\mu\textrm{m}$ and those standard deviation were 4.57∼5.12. As-prepared powders which were synthesized at 1000$^{\circ}C$ have spherical shape, sizes of 0.1∼3.0$\mu\textrm{m}$ and specific surface area of 22.34∼24.20㎡/g. Most powders consisted of {{{{ gamma }}-Al2O3 phase and transforned into ${\alpha}$-A;2O3 phase by calcination at 1100$^{\circ}C$ for 1 hr. NiO-doped Al2O3 sintered bodies had better sinterability than those of pure Al2O3 and 0.3 wt% NiO-doped Al2O3 had near theoretical density and dense microstructure.

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Effect of Oxygen Partial Pressure on Tungsten-Alumina Bonding Behavior (텅스텐-알루미나 접합거동에 미치는 산소분압의 영향)

  • 박정현;이상진
    • Journal of the Korean Ceramic Society
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    • v.27 no.6
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    • pp.755-762
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    • 1990
  • The tungsten paste was printed on the surface of 92% alumina sheet which was made by type casting process. The printed tungsten was bonded on the Al2O3 by co-firing in reducing atmosphere. During the co-firing, the binder burn-out was easier in wet H2 atmosphere than in dry H2, which affected sintered density. In practically, the use of wet H2 above 100$0^{\circ}C$ was beneficial for density of alumina and bond strength. This phenomena occured more distinctly when atmosphere varied from dry H2 to wet H2 than varied dew point in wet H2. In wet H2, the improvement in bonding strength can be attributed to good glass migration into the metal layer due to inhibition of the tungsten particle growth, with increase of alumina density, at the temperatrue higher than 100$0^{\circ}C$.

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