• Title/Summary/Keyword: Functional relation

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Analysis of the spectral characteristics of white light-emitting diodes under various thermal environments

  • Jeong, Su-Seong;Ko, Jae-Hyeon
    • Journal of Information Display
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    • v.13 no.1
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    • pp.37-42
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    • 2012
  • An empirical functional form was suggested for the analysis of the emission spectrum of high-power light-emitting diode (LED) consisting of a sharp blue peak from the LED chips and a broad yellow peak from the phosphor layer. The peak positions, half widths, shape parameters, and amplitudes of these two peaks were reliably obtained as a function of the temperature, and the results were discussed qualitatively in relation with the junction temperature. The adoption of an inert liquid was found to have significantly reduced the LED temperature and the color shift of the emitted light. The phenomenological approach used in this study may be helpful in the simulation of the LED spectrum under various thermal conditions, and may thus be helpful in the improvement of the device performance.

Numerical Study for Mixing Characteristics of an Oscillating Micro-stirrer (미소진동교반기의 혼합특성에 대한 수치적 연구)

  • Kim, Yong-Dae;Maeng, Joo-Sung
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.309-312
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    • 2006
  • Effective mixing is an important problem in microfluidics for chemical and biomechanical applications. In this study, the influences of the Reynolds number and the oscillating frequency on mixing characteristics of micro-stirrer are studied in a microchannel with single stirrer. The influence of fluid inertial effects in an active mixer is first discussed. It is found that the stirring effects by stirrer oscillation are promptly attenuated at low Reynolds number, which makes greatly difficult the rapid mixing. As the inertial effects are increased, the chaotic advection is generated and then developed. The mixing phase is finally developed some mushroom shaped structure. And the mixing efficiency is also studied as a function of the oscillating frequency. We found that the mixing efficiency does not always increase with higher oscillating frequency of stirrer. Consequently, we found the functional relation between the optimal frequency of a stirrer and the Reynolds number.

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Association of Sexual Maturation and Parent-Child Communication on Maturity Fears in Elementary School Girls (초등학교 여학생의 성적 성숙도, 부모자녀 의사소통 및 성숙 불안에 관한 연구)

  • Cho, Hun Ha;Moon, So-Hyun
    • Child Health Nursing Research
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    • v.22 no.2
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    • pp.137-144
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    • 2016
  • Purpose: The purpose of this study was to investigate factors that influence maturity fears in elementary school girls. Methods: The participants were 118 3rd and 4th grade students from 3 elementary schools in 3 cities in Korea. Data were collected using questionnaires which included measurement scales for the relative variables and demographic data. Data were analyzed using t-test, ANOVA, Pearson correlation coefficients, and hierarchial regression analysis with SPSS/WIN 21.0. Results: The significant predictors of maturity fears were weight, father-child communication, frequency of maturity communication with father, and close relation with mother. Conclusion: For effective management of maturity fears in elementary school girls, programs including weight control, functional communication with father and supportive nurturance of mother should be developed.

Embodying RBD and Reliability Analysis Technology base on Web (웹 기반 RBD 구현 및 신뢰도 평가기술)

  • 송준엽;이승우;이후상;조복기
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1541-1544
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    • 2003
  • In this study, embodying reliability block diagram based on the web and reliability analysis technology are developed. RBD(reliability Block Diagram) represents the functional relation between elements in any product. Among relations between elements. there are serial, parallel, bridge, and stand by, etc. Advantages of developed system are integrated datum about reliability (NPRD, EPRD, MIL-HDBK 217F, NSWC. OREDA. Bellcore, and domestic institutes & companies datum). graphic user interface for convenience, and the various service analyzes the failure history data of parts.

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A study of the effect of walking speed upon gait parameters and foot-ground reaction forces (보행속도가 보행특성모수 및 지면반발력에 미치는 영향에 관한 연구)

  • 황규성;정민근;이동춘
    • Journal of the Ergonomics Society of Korea
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    • v.11 no.1
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    • pp.93-101
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    • 1992
  • Gait parameters for the Korean normal adults were compared with sex and age. Time-distance measurements and ground reaction force parameters were studied in relation to walking speed. Regression analysis was performed to establish functional relations between walking speed and various gait parameters. It is found that cardence and stride length varied linearly with walking velocity whereas time of double support was inversely proportional to walking velocity. The amplitude of ground reaction force was increased with increasing velocities of gait due to the greater heel-strike force and toe-off forces associated with these higher velocities. The results of this study can be usefull utilized as basic data to design and evaluate prosthetic devices, and to detect abnormal gait performances.

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Research on construction and application of RIMS with "intelligent BOM" (RIMS "지능형 BOM" 구축과 활용에 관한 연구)

  • Park, Soo-Choong;Lee, Do-Sun;Choi, Kwang-Suk;Son, Yung-Gin;Kim, Myung-Kyu
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.1499-1504
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    • 2007
  • This dissertation explains the construction of the expert system which can manage diagnosis and administration of trouble using circuit diagram through connection between BOM and ability term and makes up for problem which have designed RIMS with name of parts. Also this dissertation explains that existing BOM has no regard organic relation of parts and functional and systematic appearance of the flow of electricity or air. Construction of expert system and "Be enlivened BOM" with flowing electricity and air can solve problems about overlapping parts carrying out other functions with the same name of parts following to simple and physical BOM management and having mistaken trouble of the end caused by basis for trouble of the end.

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A Numerical Modeling of Thawing Rate for Frozen Pork using High Pressure Assisted Thawing Technique

  • Ryu, Hyun-Sik;Park, Sung-Hee;Min, Sang-Gi
    • Proceedings of the Korean Society for Food Science of Animal Resources Conference
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    • 2004.10a
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    • pp.310-315
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    • 2004
  • The objective of this study was to provide the optimum thawing condition under different level of high pressure(50, 100, 150 and 200 MPa) using high pressure assisted technique which can improve the quality of frozen and thawed pork. The calculated thawing rate from the results depending on the high pressure showed the strong trend of increased thawing rate under pressurized condition(P<0.05). And then, the numerical modeling was executed to predict the thawing rate influenced by the pressure level using exponential regression, LnY=0.70623 + 0.00433 ${\cdot}$ P ($R^2=0.9985$), and it was fairly fit for the functional relation between the thawing rate(Y) and pressure(P) with comparatively high coefficient, $R^2$ of determination.

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A Study on the Selection Criteria of Fashion Shopping Area according to Clothing Consumption Value and Fashion Leadership

  • Park, Hye-Won;Ryou, Eun-Jeong
    • The International Journal of Costume Culture
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    • v.5 no.1
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    • pp.26-33
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    • 2002
  • Re purposes of this study were to determine consumers' selection criteria of fashion shopping area and to examine the effects of clothing consumption value and fashion leadership on the selection criteria of fashion shopping area. In addition, the third purpose was to clarify the relation beかeon the above variables and shopping intent. The data were collected from 198 females in their twenties using questionnaire. The results could be summarized as follows. First, the selection criteria of fashion shopping area were composed of 5 factors: scale & variety of shopping area, convenience of location, entertainment, physical service, and atmosphere. Second, the fashion leadership and clothing consumption value except functional and social values had an effect on the selection criteria fashion shopping area. Particularly, the attractiveness-sought value best explained the selection criteria. Third, the fashion leadership and selection criteria fashion shopping area had an effect on the shopping intent. The effect clothing consumption value was not significant.

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Blood-neural barrier: its diversity and coordinated cell-to-cell communication

  • Choi, Yoon-Kyung;Kim, Kyu-Won
    • BMB Reports
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    • v.41 no.5
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    • pp.345-352
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    • 2008
  • The cerebral microvessels possess barrier characteristics which are tightly sealed excluding many toxic substances and protecting neural tissues. The specialized blood-neural barriers as well as the cerebral microvascular barrier are recognized in the retina, inner ear, spinal cord, and cerebrospinal fluid. Microvascular endothelial cells in the brain closely interact with other components such as astrocytes, pericytes, perivascular microglia and neurons to form functional 'neurovascular unit'. Communication between endothelial cells and other surrounding cells enhances the barrier functions, consequently resulting in maintenance and elaboration of proper brain homeostasis. Furthermore, the disruption of the neurovascular unit is closely involved in cerebrovascular disorders. In this review, we focus on the location and function of these various blood-neural barriers, and the importance of the cell-to-cell communication for development and maintenance of the barrier integrity at the neurovascular unit. We also demonstrate the close relation between the alteration of the blood-neural barriers and cerebrovascular disorders.

Theoretical analysis on the correlation between the amount of available phosphorus and the growth rate of Chlorella ellipsoidea. (Chlorella 익 비성장율에 미치는 유효인산량과 그 이론적 분석)

  • 이주식;장남기;이태우
    • Korean Journal of Microbiology
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    • v.5 no.1
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    • pp.34-38
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    • 1967
  • Theoretical analysis reported in this paper is on the varities of the growth rate of Chlorella ellipsoidea due to the amount of available phosphorus for the purpose of the continual mass culture. Available phosphorus in the culture media of the Chlorella was also estimated at a limiting factor as this experiment. The equation between the concentration of Chlorella n and growth period t is $\frac{dn}{dt}=Kn$, and the functional relation between the Specific growth rate K and steady state period T is the following: $K=\frac{2.303}{T}$log\frac{n}{no}$ ($n_o$=initial concentration).

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