• 제목/요약/키워드: variable formation

검색결과 319건 처리시간 0.02초

Fractal 기하학을 이용한 균사의 성장과 구체 형성의 특성 분석 (Analysis of Filamentous Fungal Growth and Pellets Formation by Fractal Geometry)

  • 류두현
    • KSBB Journal
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    • 제9권5호
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    • pp.512-517
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    • 1994
  • 균류를 이용하는 생물공정의 생산성, 분리성, 유변 학적 성질에 영향을 주는 중요한 변수인 균류의 형 태를 fractal 차원을 사용하여 정량화하였다. 산업적 으로 중요한 균류인 Aspegillus oryzae와 Aspergil­l Ius niger가 초기의 접종 포자량과 탄소원의 농도를 변화시켜 액상배지에서 성장하는 경우, 디지탈 영상 분석장치를 사용하여 fractal 차원을 계산하였다. 균 사가 형성하는 구체의 특성과 fractal로 표현된 균사 의 형태와의 상관관계를 구하였다. 일반적으로 낮은 fractal 차원의 균사가 낮은 멜도(compactness)의 구체를 형성하고 외부의 모양이 불규칙적이었다.

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$n-TiO_2$ 분말의 저압화염 합성에 미치는 전구체 전달속도의 영향 (The Effect of the Precursor Delivery Rate on low Pressure Flame Synthesis of $n-TiO_2$ Powder)

  • 김태형
    • 한국분말재료학회지
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    • 제6권1호
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    • pp.75-80
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    • 1999
  • The formation of $n-TiO_2$ powder by oxidation of Ti-ethoxied vapor in a flat flame burner reactor maintained under 20 torr has been studied. The produced powder were characterized in terms of crystal structure, chemical composition by XRD and TEM. The results showed that the powder consisted of loose agglomerated anatase and rutile particles and their size were about 10 nm and 20 nm, respectively. In the course of synthesis, changes of the flame color were happened to each condition during heating up the bubbler. The flame color transition phenomena reveled that a critical precursor delivery rate was needed for the powder formation (obtainable powder yield). The critical precursor delivery rate was estimated by a simple function of the bubbler temperature and the carrier gas flow rate. The critical precursor delivery rate was reviewed as an important variable of the nanopowder synthesis.

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포트 마스킹과 흡기 밸브 타이밍이 실린더 내부의 싸이클별 HC와 NOx 생성에 미치는 영향 (Cycle-by-Cycle In-cylinder HC & NOx Formation Characteristics with Port Masking in CVVT Engine)

  • 전우주;최관희;명차리;박심수;이경환
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회B
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    • pp.3108-3113
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    • 2008
  • This paper investigated the behaviors of combustion characteristics at part load condition with various intake charge motions induced by the port masking schemes in the CVVT (Continuously Variable valve Timing) engine. Time resolved in-cylinder and exhaust emissions were measured by the fast response HC and NOx analyzers to examine their formation mechanisms and behavior characteristics. As a result, in-cylinder HC decreased with the advanced intake valve timings but HC at the exhaust port increased due to the worse combustion stabilities. However HC reduction could be achieved by the application of the port maskings with a enhancement of the engine stability. NOx also decreased with early intake timings by internal EGR but increased with the charge motion controls which enhance the combustion behavior.

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선별표지로 plasmid를 이용한 pseudomonas spp.의 원형질체 융합 (Spheroplast fusion of pseudomonas spp. using plasmid as selective marker)

  • 이주실;이미란;이영록
    • 미생물학회지
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    • 제26권4호
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    • pp.298-304
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    • 1988
  • Antibiotic resistance plasmids (RP4, pMG1, R679 and R91-5) were used as primary selective markers to detect the fusants in Pseudomonas spp. By using plasmid marker, clones containing both plasmids of parental strains were obtained as fusants by direct selection. The spheroplast fusion was occured not only between strains of interspecies, but also between strains of intergenus such as Pseudomonas and E. coli. The frequencies of fusant formation were variable from $2.8\times 10^{-1}$ to $6.0\times 10^{-4}$ -4/. In addition, chromosomal recombinants were formed among the clones with both parental plasmids in frequencies of 0.44-1.3%. The fusant formation frequency between interspecies of intraspecies was not different markedly, but stability of plasmids in fusants correlated with the phylogenic smilarity of the parental strains.

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DC 원통형 반응성 스파트링을 이용한 ITO 형성에 관한 연구 (A study on the formation of ITO by reactive DC cylindrical sputtering)

  • 조정수;박정후;하홍주;곽병구;이우근
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1995년도 춘계학술대회 논문집
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    • pp.35-38
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    • 1995
  • Indium Tin Oxide(ITO) thin film is transparent to visible ray and conductive in electricity. It is seen that the samples made by the sputtering process have high transmission rate to visible ray and high adhesion , but the planar type magnetron sputtering process with is very well known in industrial region have a defect of partial erosion on the surface of target and a high loss of target and also since the substrate is positioned in plasma, the damage on thin film surface is caused by the reaction with plasma. In cylindrical magnetron sputtering system. it is known that the loss of target is little , the damage of thin film is very little and the adhesion of thin film with substrate is strong. In this study, we have made ITO thin film in the cylindrical DC magnetron system with the variable of substrate temperature , magnetic field, vacuum condution and the applied voltage. The general temperature for formation on ITO is asked at 350 $^{\circ}C$~400$^{\circ}C$ but we have made ITO is low temperature(80-150$^{\circ}C$) By studing electrical and optical properties of ITO thin fims made by varing several condition, we have searched the optimal condition for formation in the best ITO in low temperature.

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상의색과 모자색, 모자유형이 인상 형성에 미치는 영향 (The Effect of Shirts-Color and Hat Color, Hat Design on Impression Formation)

  • 정해선;강경자
    • 복식문화연구
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    • 제12권3호
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    • pp.354-368
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    • 2004
  • The purpose of this study is to investigate the effect of Shirts-color(Different-color, Same-color) and Hat color(Red, Blue, Beige, Grey), Hat design (Beret, Cloche, Bowler, and Capeline) on impression formation. The experimental materials developed for this study were a set of stimulus and response scales. The 7-point semantic thirty stimuli color pictures of various combination of hair length, hair style, and type of hat design were manipulated by computer drawing. The subjects were 360 undergraduates living in Seoul, Kyunggi and Kyungnam. The experimental design was composed of 3 factorial designs. The result of the study can be summarized as follows; Impression factor of the stimulus consisted of the 5 different dimensions. (concentration of attention, attractiveness, gracefulness, activity, tenderness). Concentration of attention, elegance, and tenderness in case of a hat as a clue, elegance and tenderness in case of the color of upper clothes as a clue, and all the factors except attractiveness and elegance in case of the type of hat as a clue were significant factors to differences of appearance. In regarding the effect of interaction between each variable, the combination of Hat color and Shirts-color had significant effects on tenderness, Hat color and type of hat design on concentration of attention, elegance and activity.

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착용자의 체형과 의복유형, 무채색 톤 조합이 인상형성에 미치는 영향 (The Effect of Wearer's Body Type and Clothing Type, Neutral Tone Combination on Impression Formation)

  • 팽숙경;강경자
    • 한국의류학회지
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    • 제29권9_10호
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    • pp.1207-1218
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    • 2005
  • The purpose of this study is to find out the effect of wearer's body type and clothing type, neutral tone combination on impression formation. The experimental materials developed for this study are a set of stimuli and response scales(The 7-point semantic). the stimuli are 90 pictures manipulated with wearer's body type, clothing type and neutral tone variation by computer simulation. The subjects are 540 female undergraduate students in Kyung-nam. The resulte of this study are as follows : Impression factor of the stimulus consisted of the 5 demensions(tenderness, cuteness, attractiveness, elegance, intrepidity). Wearer's body type had significant effects on all five factors. Especially, it had the strongest effects on attractiveness. Clothing type had significant effects on tenderness, attractiveness, intrepidity. Neutral tone combinations had significant effects on all factors except elegance. In regarding the effect of interaction between each variable, the combination of clothing type and neutral tone combination had significant effects on attractiveness, elegance, intrepidity.

주기적으로 회전하는 원봉 주위의 후류에 관한 수치적 연구 (Numerical simulation of the flow behind a circular cylinder with a rotary oscillation)

  • 백승진;성형진
    • 대한기계학회논문집B
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    • 제22권3호
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    • pp.267-279
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    • 1998
  • A numerical study was made of flow behind a circular cylinder in a uniform flow, where the cylinder was rotationally oscillated in time. The temporal behavior of vortex formation was scrutinized over broad ranges of the two externally specified parameters, i.e., the dimensionless rotary oscillating frequency (.110.leq. $S_{f}$.leq..220) and the maximum angular amplitude of rotation (.theta.$_{max}$=15 deg., 30 deg. and 60 deg.). The Reynolds number (Re= $U_{{\inf}D}$.nu.) was fixed at Re=110. A fractional-step method was utilized to solve the Navier-Stokes equations with a generalized coordinate system. The main emphasis was placed on the initial vortex formations by varying $S_{f}$ and .theta.$_{max}$. Instantaneous streamlines and pressure distributions were displayed to show the vortex formation patterns. The vortex formation modes and relevant phase changes were characterized by measuring the lift coefficient ( $C_{L}$) and the time of negative maximum $C_{L}$( $t_{-C}$$_{Lmax}$) with variable forcing conditions.s.tions.s.s.s.

의복범주가 젊은이의 대인지각에 미치는 영향 -유행성 및 착용자의 체형과 관련지어- (The Effect of Garment Category, Fashionability and Wears' Body type on Impression Formation)

  • 김재숙;김희숙
    • 한국의류학회지
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    • 제16권4호
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    • pp.371-377
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    • 1992
  • The purposes of the study were 1) to extend the cognitive categorization theory in an attempt to explain the of garment category, fashionability, and wearer's body types on impression formation, and 2) to find out structures of wearer's impressional dimension and wearer's professional image. The research included a quasi-experiment and survey. The experimental design was a $2^{3}$full factorial design of 3 independent variables. The experimental materials developed for the study were a set of stimuli and a response scale. The stimuli consisted of 8 drawings made by 3 independent variables (garment category, fashion level, wearer's body type). Result were as follows: 1) Garment category, fashionability and wearer's body type had significant effects on impression of the 5 factors-evaluation, potency, appearance, sociability and good-bad, with exception of wearer's body type which was nonsignificant to the potency factor. 2) Garment category was most effective on the evaluation and the potency. However wearer's body type was most effect on the appearance factor and fashionability variable was most effective on the good-bad factor. It was conclued that the results supported the cognitive categorization theory on impression formation and a cognitive categorization hypothesis of clothes.

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Effect of polymer adsorption on film formation of silica/PVA suspension

  • Kim, Sun-Hyung;Sung, Jun-Hee;Ahn, Kyung-Hyun;Lee, Seung-Jong
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2009년도 추계학술발표회 논문집
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    • pp.79-84
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    • 2009
  • Understanding the polymer adsorption in particle/binder/solvent system is important to achieve successful film products. While most of the reported work has dealt with the suspension microstructure, a few studies have focused on film formation. We investigated the effect of adsorption on film formation through measurement of adsorption amount in suspension and stress development in drying film with respect to mixing time ($t_m$). All of the adsorption amount (PVA), characteristic stress ($\sigma_{ch}$) exhibited similarities expressed by the form of $1-e^{t_m/{\tau}}$. The porous and non-unifonn dried film at short tm became close-packed and uniform with longer $t_m$. We found that polymer adsorption plays the key role in film fonnation as it introduces steric repulsion in suspension and suppresses the flocculation during solvent evaporation. We also found that the mixing time for the saturated polymer adsorption is the important variable to acquire the consolidated and uniform film microstructure.

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