• Title/Summary/Keyword: density of media

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Optimal design of slider for stable flying characteristic using 4${\times}$l near-field probe array

  • Jung Min-su;Hong Eo-Jin;Park Kyoung-Su;Park No-Cheol;Yang Hyun-Seok;Park Young-Pil;Lee Sung-Q;Park Kang-Ho
    • 정보저장시스템학회:학술대회논문집
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    • 2005.10a
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    • pp.171-176
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    • 2005
  • In the information storage development, the trend of the storage device is to increase the recording density. Among such an effort, near-field probe recording is spotlighted as a method of high increasing recording density. For the successfully embodiment of storage device, the actuating mechanism of near-field probe is essentially designed. In this paper, we suggest the slider similar with conventional HDDs and design the slider using near- field probe for the purpose of applying the slider in order to control gap between probe and media. The most important object of slider design is to guarantee the flying ability and stability. For achievement of these design objects, we perform two step of optimal design process. The media is mod! eled as random displacement, which is only considered roughness of disk surface. The design slider is analyzed with dynamic state in assumed media. At this process, the optimal model is confirmed to stable flying stability.

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Text Extraction in HIS Color Space by Weighting Scheme

  • Le, Thi Khue Van;Lee, Gueesang
    • Smart Media Journal
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    • v.2 no.1
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    • pp.31-36
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    • 2013
  • A robust and efficient text extraction is very important for an accuracy of Optical Character Recognition (OCR) systems. Natural scene images with degradations such as uneven illumination, perspective distortion, complex background and multi color text give many challenges to computer vision task, especially in text extraction. In this paper, we propose a method for extraction of the text in signboard images based on a combination of mean shift algorithm and weighting scheme of hue and saturation in HSI color space for clustering algorithm. The number of clusters is determined automatically by mean shift-based density estimation, in which local clusters are estimated by repeatedly searching for higher density points in feature vector space. Weighting scheme of hue and saturation is used for formulation a new distance measure in cylindrical coordinate for text extraction. The obtained experimental results through various natural scene images are presented to demonstrate the effectiveness of our approach.

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A Study on the Fluid Flow and Heat Transfer Characteristics for the Wire-woven Bulk Kagome(WBK) Composed of Aluminum Helix Wires (알루미늄 나선형 와이어로 직조된 다층 Kagome Truss PCM의 유동 및 열전달 특성에 관한 연구)

  • Joo, Jai-Hwang;Kang, Bo-Seon;Kang, Ki-Ju
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.32 no.1
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    • pp.15-22
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    • 2008
  • Recently, ultra-lightweight materials with open, periodic cell structures take much attention owing to its potential for multi-functionality such as load bearing, thermal dissipation, and actuation. This paper presents experimental results on the fluid flow and heat transfer characteristics for the Wire-woven Bulk Kagome (WBK) composed of aluminum 1100 wires. The overall pressure drop and heat transfer of the WBK specimen was experimentally investigated under forced air convection condition. The pressure loss and heat transfer performance of the aluminum WBK were compared with other heat dissipation media. It was shown that heat transfer characteristics depended on relative density and surface area density. Comparison with metal foams and other heat dissipation media such as packed beds, lattice frame materials, louvered fins, and others suggests that the aluminum WBK competes favorably with the best available heat dissipation media in heat transfer performance.

A Study on the Hydraulic and Heat Transfer Characteristics for the Wire-woven Bulk Kagome(WBK) Composed of Aluminum Helix Wires (알루미늄 나선형 와이어로 직조된 다층 Kagome truss PCM의 유동 및 열전달 특성에 관한 연구)

  • Joo, Jai-Hwang;Kang, Bo-Seon;Kang, Ki-Ju
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.2061-2066
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    • 2007
  • Recently, ultra-lightweight materials with open, periodic cell structures take much attention owing to its potential for multi-functionality such as load bearing, thermal dissipation, and actuation. This paper presents experimental results on the hydraulic and heat transfer characteristics for the Wire-woven Bulk Kagome(WBK) composed of aluminum 1100 wires. The overall pressure drop and heat transfer of the WBK specimen have been experimentally investigated under forced air convection condition. The pressure loss and heat transfer performance of the aluminum WBK are compared with other heat dissipation media. It was shown that heat transfer depended on relative density and surface area density. Comparison with metal foams and other heat dissipation media such as packed beds, lattice frame materials, louvered fins, and other materials suggests that the aluminum WBK competes favorably with the best available heat dissipation media in heat transfer performance.

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3D Reconstruction using multi-view structured light (다시점 구조광을 이용한 3D 복원)

  • Kang, Hyunmin;Park, Yongmun;Seo, Yongduek
    • Annual Conference of KIPS
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    • 2022.11a
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    • pp.288-289
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    • 2022
  • In this paper, we propose a method of obtaining high density geometric information using multi-view structured light. Reconstruction error due to the difference in resolution between the projector and the camera occurs when reconstruction a 3D shape from a structured light system to a single projector. This shows that the error in the point cloud in 3D is also the same when reconstruction the shape of the object. So we propose a high density method using multiple projectors to solve such a reconstruction error.

Study on the High Tension on Radiography and Density of Barium Sulphate (관전압(管電壓)과 황산(黃酸)바륨의 농도(濃度)에 관(關)한 연구(硏究))

  • Kyong, Kwang-Hyon;Huh, Joon
    • Journal of radiological science and technology
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    • v.3 no.1
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    • pp.43-48
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    • 1980
  • An experimental study was carried out to make a comparison between tube voltage and density of barium sulphate in the stomach radiography. The results were summarized as follows: 1. The percentage of density on concentrations of barium sulphate as contrast media could not show in differences with changes of voltages applied X-ray tube. 2. The changes of density visualized on X-ray film mainly depend upon with thickness of stomach filled barium sulphate than the ratio of barium sulphite and plain water volume. 3. The lesions positioned in upper part within stomach exhibited their best discrimination performanance with depth in the low tube voltage, followed in order by the middle part and lower part. However, the discrimination performanance at the high tension radiography uniformly visualized over X-ray film without density in change.

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Isolation and identification of Lactobacillus inhibiting the production of halitosis by anaerobic bacteria (구취를 유발하는 혐기성 세균의 증식을 억제하는 유산 간균의 분리 및 동정)

  • Kim, Mi-Hyung;Kim, Seon-Mi
    • Journal of Korean society of Dental Hygiene
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    • v.4 no.2
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    • pp.153-163
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    • 2004
  • There are normal inhabitants doing medically useful functions in the body. There are many kinds of bacteria performing specific functions in the oral cavity. Two strains of lactic acid bacteria were isolated from normal inhabitants of children 's oral cavity, which inhibited the the production of halitosis by anaerobic bacteria. The authors identified the isolates by the lest using API 50 CHL medium kit. 1. Two isolates were Gram-positive bacilli and produced hydrogen peroxide. 2. The optical density was 1.286 in the supernatant of Fusobacterium nucleatum after vortexing for 30 minutes, whereas in the supernatant of combined Fusobacterium nucleatum and each isolate, they were reduced to 0.628 and 0.497, which the percentages of coaggregation between them were 29.4% and 57.8%, respectively. 3. The optical density of Fusobacterium nucleatum precipitate was 1.794 in the culture media containing cysteine and $FeSO_4$, being reduced to 1.144 and 0.915 in the coaggregated precipitates of Fusobacterium nucleatum and each isolate. 4. The optical density of Porphyromonas gingivalis precipitate was 1.932 in the culture media, being reduced to 1.170 and 1.266 in the coaggregated precipitates of Porphyromonas gingivalis and each isolate. 5. When two isolates were tested with API 50 CHL medium kit, those were identified as Lactobaciallius salivarius and Lactobacillus delbrueckii subsp. lactis.

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Statistical Selection of Amino Acids Fortifying a Minimal Defined Medium for a High-level Production of the Kringle Fragments of Human Apolipoprotein(a)

  • Lim, Hyung-Kwon;Kim, Sung-Geun;Jung, Kyung-Hwan;Seo, Jin-Ho
    • Journal of Microbiology and Biotechnology
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    • v.14 no.1
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    • pp.90-96
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    • 2004
  • A synthetic defined medium, fortified with amino acids, was developed for the stable production of the kringle fragments of human apolipoprotein(a) (apo(a)), rhLK68. Using a complex rich medium containing yeast extract and a high-cell-density fed-batch culture, the expression level of rhLK68 reached 17% of the total cellular protein, which corresponded to $5\;g\;l^{-1}$ of the culture. To replace the complex media with chemically defined media, several amino acids that positively affect cell growth and gene expression were chosen by a statistical method. The various combinations of the selected amino acids were tested for its fortifying effect on a minimal defined medium. When glutamine only was added, the overall expression level of rhLK68 reached 93% of the complex rich medium increasing the specific expression level by 22.4% and decreasing the cell growth by 24%. Moreover, the addition of glutamine resulted in a 2-fold increase in the concentration of rhLK68 in the culture broth, compared with the minimal defined medium. The synthetic defined media developed in this study could be generally applied to high-cell-density cultures of the recombinant Escherichia coli BL21(DE3), especially for the production of therapeutic proteins that require a strict quality control of the culture media and fermentation processes.

Rh-doped carbon nanotubes as a superior media for the adsorption of O2 and O3 molecules: a density functional theory study

  • Cui, Hao;Zhang, Xiaoxing;Yao, Qiang;Miao, Yulong;Tang, Ju
    • Carbon letters
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    • v.28
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    • pp.55-59
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    • 2018
  • Transition-metal-embedded carbon nanotubes (CNTs) have been accepted as a novel type of sensing material due to the combined advantage of the transition metal, which possesses good catalytic behavior for gas interaction, and CNTs, with large effective surface areas that present good adsorption ability towards gas molecules. In this work, we simulate the adsorption of $O_2$ and $O_3$ onto Rh-doped CNT in an effort to understand the adsorbing behavior of such a surface. Results indicate that the proposed material presents good adsorbing ability and capacities for these two gases, especially $O_3$ molecules, as a result of the relatively large conductivity changes. The frontier molecular orbital theory reveals that the conductivity of Rh-CNT would undergo a decrease after the adsorption of two such oxidizing gases due to the lower electron activity and density of this media. Our calculations are meaningful as they can supply experimentalists with potential sensing material prospects with which to exploit chemical sensors.

Analysis on Induced Current Density by Electric Field of Human under the 765 kV Transmission Line Considering Permittivity and Conductivity (유전율 및 도전율을 고려한 765kV 송전선하의 전계에 의한 인체내부 유도 전류밀도 해석)

  • 민석원;송기현;양광호;주문노
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.53 no.8
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    • pp.461-465
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    • 2004
  • This paper analysed the induced current density by electric field of human body under the 765 kV transmission line considering permittivity and conductivity. As permittivity of human body is very high as $10^6$ at 60 Hz, special numerical computation technique in Surface Charge Method(SCM) for composite media with extremely different properties is applied to reduce calculation error of induced current density and electric field inside the human body. Calculation results show that the average of the induced current density inside human body is about 3mA/$m^2$, which is less than ICNIRP criterion (10mA/$m^2$).