• Title/Summary/Keyword: limitation

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Analysis of Thermal Effect on Tension of a Moving Web in Roll-to-Roll Printed Electronics (롤투롤 인쇄 전자 시스템에서 유연기판의 열변형을 고려한 웹의 장력거동 분석)

  • Lee, Jong-Su;Lee, Chang-Woo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.12 no.5
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    • pp.9-15
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    • 2013
  • Roll-to-roll printing technology has lately become a subject of special interests in the field of printed electronics. Since this technology has the advantage that continuous and mass production is possible. And for high precision register control is required in multi-layer printing to produce the electronic devices, this is one of the most important technologies in roll-to-roll printing technology. Register error could be generated by various reasons like eccentricity of roll and thermal deformation due to temperature variation in drying section. In this study, the effect of tension variation on the register was analyzed. The results of these analyses show that it is essential to consider the tension disturbance which is generated by the change of temperature in drying section, and conventional register model has limitation to estimate the register error. In order to overcome the limitation of the register model, advanced register model based on the SI process was developed. Also, the performance of the developed model was verified experimentally.

A migration based reconstruction algorithm for the imaging of defects in a plate using a compact array

  • Muralidharan, Ajith;Balasubramaniam, Krishnan;Krishnamurthy, C.V.
    • Smart Structures and Systems
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    • v.4 no.4
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    • pp.449-464
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    • 2008
  • An array based, outward monitoring, ultrasonic guided wave based SHM technique using a single transmitter and multiple receivers (STMR), with a small footprint is discussed here. The previous implementation of such SHM arrays used a phase-reconstruction algorithm (that is similar to the beam-steering algorithm) for the imaging of reflectors. These algorithms were found to have a limitation during the imaging of defects/reflectors that are present in the "near-field" of the array. Here, the "near-field" is defined to be approximately 3-4 times the diameter of the compact array. This limitation is caused by approximations in the beam-steering reconstruction algorithm. In this paper, a migration-based reconstruction algorithm, with dispersion correction in the frequency domain, is discussed. Simulation and experimental studies are used to demonstrate that this algorithm improves the reconstruction in the "near-field" without decreasing the ability to reconstruct defects in the "far-field" in both isotropic and anisotropic plates.

Nutritional Management in Patients with Chronic Obstructive Pulmonary Disease (만성폐쇄성폐질환 환자의 영양관리)

  • Lee, Kwan-Ho
    • Journal of Yeungnam Medical Science
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    • v.21 no.2
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    • pp.133-142
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    • 2004
  • Chronic obstructive pulmonary disease(COPD) is characterized by a not entirely reversible limitation in the airflow. An airflow limitation is progressive and associated with an abnormal inflammatory response of the lung to gases and harmful particles. In COPD, the weight loss is commonly observed and there is a negative impact on the respiratory as well as skeletal muscle function. The pathophysiological mechanisms that result in weight loss in COPD are not fully understood. However, the mechanisms of weight loss in COPD may be the result of an increased energy expenditure unbalanced by an adequate dietary intake. The commonly occurring weight loss and muscle wasting in COPD patients adversely affect the respiratory and peripheral muscle function, the exercise capacity, the health status, and even the survival rates. Therefore, it is very valuable to include management strategies that the increase energy balance in order to increase the weight and fat free mass. A Better understanding of the molecular and cellular pathological mechanisms of COPD can improve the many new directions for both the basic and clinical investigations. The Nutritional supply is an important components of a multidisciplinary pulmonary rehabilitation program. Future studies combining an exercise program, the role of anabolic steroids, nutritional individualization, a more targeted nutritional therapy, and the development of new drugs including anti-cytokines is needed for the effective management of COPD.

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A Study on an Improved MVE for Estimating the Direction of Arrival of Multiple Sources (다중 신호원의 도래방향 추정을 위한 개선된 MVE에 관한 연구)

  • 정용민;신준호;김용득
    • Proceedings of the IEEK Conference
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    • 1999.06a
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    • pp.687-690
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    • 1999
  • Many high-resolution algorithms based on the eigen-decomposition analysis of observed covariance matrix, such as MVE, MUSIC, and EVM, have been proposed. However, the resolution of spectral estimates for these algorithms is severely degraded when Signal-to-Noise Ratio (SNR) is low and arrival angles of signal are close to each other. And EVM and MUSIC is powerful for the characteristic of SNR. But have the limitation that the number of signals presented is known. While MVE is bad the characteristic of SNR. In this study, we propose a modified MVE to enhance the resolution for Direction-Of-Arrival (DOA) estimation of underwater acoustic signal. This is to remove the limitation that existing algorithms should know the information for the number of signals. Because the algorithms founded on the eigen value estimate DOA with only the noise subspace, they have the high-resolution characteristic. And then, with the method reducing the effect of the signal subspace, we are to reduce the degradation because of complementary relationship between the signal subspace and the noise subspace. This paper, with using the simulation data, we have estimated the proposed algorithms, compared it with other high-resolution algorithms. The simulation results show that the modified MVE proposed is accurate and has a better resolution even though SNR is low, under the same condition.

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A Study on the Workflow of Cinematography with 4K High Speed Camera (4K 초고속 카메라 촬영기술의 워크플로우에 관한 연구)

  • Kim, Sang-Il;Park, Sung-Chul;Kim, Jung-Ho;Kwon, Soon-Chul;Lee, Seung-Hyun
    • Journal of Digital Contents Society
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    • v.15 no.3
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    • pp.425-432
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    • 2014
  • 4K high speed camera shooting enables shooting of fast subjects in Full HD 4 times resolution without motion blur due to increase in resolution and shutter speed. However, this shooting incurs several limitations including focus, intensity of radiation and increase in data quantity. As lack of intensity of radiation may occur due to increased shutter speed, it is shoot by opening aperture and limitation in focusing follows. In addition, there is limitation in shooting records since it has restriction in storage due to increased resolution and frame rate. In this regard, this study aims to analyze the limitations shown above through production case of 4K high speed camera (Phantom Flex 4K) and to design effective workflow to overcome this.

A study on the Insulation Performance of the SuperWindow considering the Evaluation of Building Energy Rating (건물에너지효율등급 적용에 따른 초단열 슈퍼윈도우 열성능 평가)

  • Jang, Cheol-Yong;Kim, Chi-Hoon;Ahn, Byung-Lip;Hong, Won-Hwa
    • Journal of the Korean Solar Energy Society
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    • v.30 no.1
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    • pp.1-6
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    • 2010
  • Generally, the building's windows and ventilation for the purpose of mining and the vista and windows by emotional engineering design area is a growing trend.In addition, the building regulation U-value limitation of window is $3.3W/m^2{\cdot}K$ in southern regions, while U-value limitation of wall is $0.35{\sim}0.58W/m^2{\cdot}K$. It means that the energy loss through windows is six times more than it through wall. Therefore, the purpose of this study is to evaluate the environmental performance of the super window system by verification experiment. The results of this study are as follows; 1) The insulation performance of super window system is $1.44\;W/m^2^{\circ}C$ 2) Super Window compared to a normal window reduce heating energy requirements have been 5.3% 3) Compared to a normal window, Super window savings rate was 4.1% lower 4) Building energy efficiency rating was up to 1 rating from 2 rating.

Candida albicans Can Utilize Siderophore during Candidastasis Caused by Apotransferrin

  • Lee Jue-Hee;Han Yong-Moon
    • Archives of Pharmacal Research
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    • v.29 no.3
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    • pp.249-255
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    • 2006
  • Ability of iron acquisition of pathogenic microorganisms functions as a virulence factor. Candida albicans, a fungal pathogen that requires iron for growth, is susceptible to growth retardation by high-affinity iron binding proteins such as transferrin. Recently, we reported that C. albicans could utilize the heme as a part of heme-containing proteins dissociated by heme oxygenase, CaHMX1. In search of another pathway that C. albicans can use to bypass the growth regulation produced by iron limitation, this present study examined utilization of non-candidal siderophores such as Desferal and rhodotorulic acid (RA) for acquisition of inorganic iron by the fungus. C. albicans secreting no siderophores was cultured in iron-free (pretreated with apotransferrin for 24 h) (culture medium). Once growth of the yeast reached stasis from iron starvation, a siderophore was added to the culture media. Results showed that cultures containing apotransferrin within a dialysis membrane recovered growth to the level of untreated controls, whereas C. albicans yeast cells in direct contact with soluble iron-free (apo) transferrin recovered growth only partially. When static growth from iron limitation was reached, the addition of siderophore-apotransferrin complex to culture medium also permitted the yeast to recover growth from apotransferrin growth regulation. All the data show that C. albicans can utilize the non-candidal siderophores for iron acquisition under transferrin regulation as can pathogenic bacteria.

Comparison of the Limitation of Stability between Flatfeet and Neutral Feet (편평발과 정상발의 무게중심한계 비교)

  • Han, Jin-Tae
    • PNF and Movement
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    • v.15 no.3
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    • pp.311-316
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    • 2017
  • Purpose: Flatfeet are one of the risk factors of foot dysfunction and postural imbalance. The purpose of this study was to compare the limitation of stability (LOS) for the center of gravity (COG) between flatfeet and neutral feet on stable and unstable support surfaces. Methods: The study included 26 healthy, adult male participants: 14 with normal feet and 12 with flatfeet. The subjects were asked to incline the trunk maximumly to the left, right, anterior, and posterior directions and were asked to keep their feet on the floor with the knee extension. The subjects had 30 seconds of rest time between the tasks. The LOS (anterior, posterior, left, right) of COG was measured by Balance Trainer (BT4, Hur-labs, Tampere, Finland). An independent t- test was used to compare the LOS of COG between flatfeet and normal feet on stable and unstable support surfaces, respectively. Results: The LOS of the flatfeet group was generally decreased on stable support surfaces as compared to that of neutral feet, but it was not significantly different (p>0.05), while the LOS of the flatfeet group was significantly decreased compared to that of neutral feet on unstable support surfaces (p<0.05). Conclusion: This study suggested that the LOS of individuals with flatfeet may be decreased on unstable support surfaces and the postural balance of the flatfeet group may easily be disturbed on an unstable support surface.

Condition Monitoring of Rotating Machine with a Change in Speed Using Hidden Markov Model (은닉 마르코프 모델을 이용한 속도 변화가 있는 회전 기계의 상태 진단 기법)

  • Jang, M.;Lee, J.M.;Hwang, Y.;Cho, Y.J.;Song, J.B.
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.22 no.5
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    • pp.413-421
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    • 2012
  • In industry, various rotating machinery such as pumps, gas turbines, compressors, electric motors, generators are being used as an important facility. Due to the industrial development, they make high performance(high-speed, high-pressure). As a result, we need more intelligent and reliable machine condition diagnosis techniques. Diagnosis technique using hidden Markov-model is proposed for an accurate and predictable condition diagnosis of various rotating machines and also has overcame the speed limitation of time/frequency method by using compensation of the rotational speed of rotor. In addition, existing artificial intelligence method needs defect state data for fault detection. hidden Markov model can overcome this limitation by using normal state data alone to detect fault of rotational machinery. Vibration analysis of step-up gearbox for wind turbine was applied to the study to ensure the robustness of diagnostic performance about compensation of the rotational speed. To assure the performance of normal state alone method, hidden Markov model was applied to experimental torque measuring gearbox in this study.

Fabrication of 6.4 cm single grain $YBa_2$$Cu_3$$O_x$ (6.4cm 크기의 일방향 성장된Y$Ba_2$$Cu_3$$O_x$ 제조)

  • 박병삼;한상철;한영희;정년호;윤희중;김경진;성태현;오제명
    • Progress in Superconductivity
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    • v.5 no.2
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    • pp.114-117
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    • 2004
  • We fabricated large single grain YBa$_2$Cu$_3$O$_{x}$ (Y-123) superconductors. The single grain Y-123 was grown by top seeded melt growth (TSMG) method. In a conventional box furnace with uniform temperature distribution, it was very difficult to grow large single grain Y-123 superconductors due to the size limitation in growth. To overcome the size limitation, we applied a radial thermal gradient (lower temperature at sample center and higher temperature on the sample edge) to the TSMG process. In this case, large single grain Y-123 could be easily grown. This is attributed that the liquid of the sample edge was maintained at the high temperature compared to the growth front. Using this method, we successfully fabricated a large single grain Y-123 of 6.4 cm X6.4 cm

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