• Title/Summary/Keyword: $Theta^*$

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Research on a New Vision Test Chart Measuring Visual and Spatial Sense of Moire Fringes (무아레 무늬의 시각적 공간감각을 측정하는 시표로서의 가능성 조사)

  • Woo, Hyun Kyung;Lee, Seongjae;Jeong, Youn Hong
    • Journal of Korean Ophthalmic Optics Society
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    • v.15 no.3
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    • pp.241-245
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    • 2010
  • Purpose: In this work we suggested a grating chart of vision test which could be used to measure the sense of distance and motion of object. Methods: A couple of gratings with periodic structure were fabricated. Through a lens the grating images showing geometrical shapes were projected on a vision test chart in order to form a new grating chart of vision test. In rotating and translating the gratings the examinee perceived the variation of position of gratings by the variation of the sense of distance and motion. Results: The results of the sense of distance and motion measured in rotating and translating the gratings showed the average errors of ~2.98% and ~1.73% at $\theta=15^{\circ}$ respectively compared to calculated values. Conclusions: The grating chart of vision test suggested in this work can be used as a new test chart that lets an examinee perceive a sense of distance and motion of object.

Retrogradaion of Rice Flour Gels with Different Storage Temperature (저장온도에 따른 쌀가루 겔의 노화)

  • Kim, Jeong-Ok;Shin, Mal-Shick
    • Applied Biological Chemistry
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    • v.39 no.1
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    • pp.44-48
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    • 1996
  • Effects of storage temperature on the retrogradation of 50% nonwaxy rice flour gels stored at $20^{\circ}C,\;4^{\circ}C\;and\;-18^{\circ}C$ for 6 days were investigated by ${\alpha}-amylase-iodine$ method, differential scanning calorimetry(DSC) and x-ray diffractometry. The retrogradation of gels increased with increasing storage time and the initial retrogradation rate was higher. The degree of retrogradation gels stored at different temperature increased as following order, $-18^{\circ}C>20^{\circ}C>4^{\circ}C$. The enthalpy of retrograded rice flour by DSC showed similar as the degree of retrogradation by ${\alpha}-amylase-iodine$ method, but the differences between storage temperatures were clear in using ${\alpha}-amylase-iodine$ method. X-ray diffraction patterns of gels stored at $4^{\circ}C\;and\;20^{\circ}C$ showed small peaks at $2{\theta}=17^{\circ}\;and\;20^{\circ}$, but the difference was not detected.

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A Study on the Development of Reinforced Earth wall by Geotextile (토목섬유를 이용한 보강토옹벽의 개발)

  • 도덕현;유능환
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.28 no.2
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    • pp.63-73
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    • 1986
  • The model was developed by applying the principles of Bacot and Vidal to measure the behavior of deformation of the reinforced earth wall, and various tasts were performed by using the plastic fabric filter and the galvanized steel plate as a strip. The results obtained are as follows; 1. When the reinforced earth wall is deformed by the load, the strip is completely reinforced by the backfill materials and changed to the rigid block state, under the state of failure which permits sliding only, the next theoretical equation is formed. (H/L) . tan$\theta$ [cosO-sinOtanO] =2sinO[tan($\theta$ +0) +tanO] 2.The degree of the mutual reinforcement of the backfill material and the strip depend on the physical characteristics of the each material especially the angle of shearing resistance of the backfill material is desirable over 20$^{\circ}$ and, if it is over 400, its function could be a maximum. 3.The distribution of the maximum tensile strain of the reinforcement is changing with the height of reinforced earth wall, and when the height from bottom of the reinforced earth wall is 1.85 to 3. 35m, the maximum tensile strain appears at 2m from the skin element. The maximum tensile strain is increased by the depth of the reinforced earth wall from surface, and increased with the lapse of time after construction. 4.The failure surface of the reinforced earth wall by the concrete skin was about 60$^{\circ}$and the failure behavior of the reinforced earth wall in which the fabric filter was buried was slow, and so the pore pressure could be decreased. 5.It is possible to construct the fabric retained earth wall by the plastic fabric filter only. And the reinforcing effect between the steel plate and the plastic fabric filter is not largely different. however, in the aspect of the economic durability, the plastic fabric filter is more advantageous. 6.The reinforcing action mainly depends on the width and the length of the reinforcing materials, if possible, the full width is advantageous to enlarge the contact area with backfill. but considering the economic aspect, it is neccessary to develop the method controlling the space of the strip.

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Basic Study on the Heat Transfer During Rapid Freezing of Syobean Seed by Liquid Nitrogen

  • Kawano, Toshio;Nakano, Kohei;Murata, Satoshi
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1993.10a
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    • pp.443-452
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    • 1993
  • Direct freezing tests of soybean seed by liquid nitrogen were carried out at various moisture contents and the following important conclusions were drawn from the results of temperature measurements of soybean seed and photographs of bubbles generated on its surface : 1) Assuming that the temperature gradient in a soybean seed is negligible because of its small seed size and the freezing ratio is followed the Heiss's formula, and a differential equation based on the heat energy balance was introduced . The equation was easily solved by the Runge-Kutta-Gill method and the predicted values of the temperature were in good agreement with the observed data. 2) The photographs of bubble generation during freezing showed the boiling mode was nucleate, and then the most suitable formula on the nucleate boiling heat transfer was introduced from many formulate proposed up to now by fitting the calculated values based on the formula to the observed data. The formula used for the predict on of the seed temperature was as follows: $\frac{{\partial}T_s}{\partial\theta}\;=\;-\frac{{\alpha}(T_s\;-\;T_L)^{3.3}}{W(C_s\;-\;\frac{{\delta}m(CT_s\;+\;{\sigma})}{T_s^2})}$ where C = difference of the specific heat between pure ice and water m=moisture content of soybean seed $T_s$ = seed temperature $T_L$ = Temperature of liquid nitrogen W = mass of soybean seed $\alpha$ = proportional constant $\delta$ = constant depends on variety or the type of seed $\theta$ = time $\sigma$ = latent heat of melting of pure ice This study will give important information in the hydro-freezing technique by liquid nitrogen, available as a new technique of processing agricultural products in the near future.

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Role of Dopamine Receptors on Electroencephalographic Changes Produced by Repetitive Apomorphine Treatments in Rats

  • Jang, Hwan-Soo;Kim, Ji-Young;Kim, Sang-Heon;Lee, Maan-Gee
    • The Korean Journal of Physiology and Pharmacology
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    • v.13 no.3
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    • pp.147-151
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    • 2009
  • Repeated psychostimulants induce electroencephalographic (EEG) changes, which reflect adaptation of the neural substrate related to dopaminergic pathways. To study the role of dopamine receptors in EEG changes, we examined the effect of apomorphine, the dopamine D1 receptor antagonist, SCH-23390, and the D2 receptor antagonist, haloperidol, on EEG in rats. For single and repeated apomorphine treatment groups, the rats received saline or apomorphine for 4 days followed by a 3-day withdrawal period and then apomorphine (2.5 mg/kg, i.p.) challenge after pretreatment with saline, SCH-23390, or haloperidol on the day of the experiment. EEGs from the frontal and parietal cortices were recorded. On the frontal cortex, apomorphine decreased the power of all the frequency bands in the single treatment group, and increased the theta (4.5 ${\sim}$ 8 Hz) and alpha (8 ${\sim}$ 13 Hz) powers in the repeated treatment group. Changes in both groups were reversed to the control values by SCH-23390. On the parietal cortex, single apomorphine treatment decreased the power of some frequency bands, which were reversed by haloperidol but not by SCH-23390. Repeated apomorphine treatment did not produce significant changes in the power profile. These results show that adaptation of dopamine pathways by repeated apomorphine treatment could be identified with EEG changes such as increases in theta and alpha power of the frontal cortex, and this adaptation may occur through changes in the D1 receptor and/or the D2 receptor.

Characterization of Mungbean (Phaseolus aureus L.) Starch (각종 전분으로 만든 교질상 식품의 특성에 관한 연구 - 녹두 전분의 이화학적 특성 -)

  • Kim, Wan-Soo;Lee, Hei-Soo;Kim, Sung-Kon
    • Applied Biological Chemistry
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    • v.23 no.3
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    • pp.166-172
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    • 1980
  • Starch granules of mungbean observed by microscope and scanning microscope were oval or round, $8{\sim}13{\mu}$ wide, and $18{\sim}30{\mu}m$ long. X-ray diffraction of the starch granules resulted weak crystallinity at $2{\theta}\;16.9^{\circ}$ The blue value of the starch was 0.36, amylose content 22.7%, alkali number 8.52, ferricyanide number 1.06, and water binding capacity of 81.6%. Swelling of the starch was negligible until $50^{\circ}C$, thereafter it increased rapidly. Optical transmittance of 0.3% starch suspension was increased rapidly from $65^{\circ}C$ and the gelatinization at $65{\sim}90^{\circ}C$ was of single stage. Amylogram patterns of the 6.7 and 8% starch solution were similar with no peak viscosity. The time constant for retrogradation of 40% starch gel stored at $21^{\circ}C$ was 1.99 days.

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Massage Therapy of Electrical Chair-Massager Effects on EEG Patterns (체어형 전동 안마기의 마사지가 뇌파 패턴에 미치는 영향)

  • Kim, Yong-Dae;Choi, Dong-Hyuk;Chang, Yun-Seung;Lee, Hyun-Ju;Tae, Ki-Sik
    • The Journal of the Korea Contents Association
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    • v.10 no.6
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    • pp.364-372
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    • 2010
  • The aim of this study was to evaluate effects of EEG patterns induced by three types ((1) resting mode(control group), (2) light massage mode, (3) strong massage mode in the electrical chair-massager for 15 minutes) in a sample of 16 healthy adults. Changes in anxiety and stress were assessed, and electroencephalogram was recorded. Anxiety scores(STAI: State Anxiety Inventory, VAS: Visual Analog Scale) decreased in all groups. For anxiety scores, the strong massage group showed the greatest decrease in stress. All groups also showed an increase in delta and theta activity, but only strong massage group showed a signigicant difference. All groups showed a decrease in alpha activity. Also, EEG changes in two groups except a control group showed a decrease in beta activity.

Molecular Interactions of a Replication Initiator Protein, RepA, with the Replication Origin of the Enterococcal Plasmid p703/5

  • Cha, Kyung-Il;Lim, Ki-Hong;Jang, Se-Hwan;Lim, Wang-Jin;Kim, Tae-Hyung;Chang, Hyo-Ihl
    • Journal of Microbiology and Biotechnology
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    • v.17 no.11
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    • pp.1841-1847
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    • 2007
  • We previously identified the origin of replication of p703/5, a small cryptic plasmid from the KBL703 strain of Enterococcus faecalis. The origin of replication contains putative regulatory cis-elements required for replication and a replication initiator (RepA) gene. The replicon of p703/5 is similar in its structural organization to theta-type plasmids, and RepA is homologous to a family of Rep proteins identified in several plasmids from Gram-positive bacteria. Here, we report molecular interactions between RepA and the replication origin of p703/5. DNase I footprinting using recombinant RepA together with electrophoretic mobility shift assays confirmed the binding of RepA to the replication origin of p703/5 via iterons and an inverted repeat. We also demonstrated the formation of RepA dimers and the different binding of RepA to the iteron and the inverted repeat using gel filtration chromatographic analysis, a chemical crosslinking assay, and electrophoretic mobility shift assays in the presence of guanidine hydrochloride. Our results suggest that RepA plays a regulatory role in the replication of the enterococcal plasmid p703/5 via mechanisms similar to those of typical iteroncarrying theta-type plasmids.

Structural and Electrical Properties of $CuGaS_2$ Thin Films ($CuGaS_2$ 반도체 박막의 구조적 및 전기적 특성)

  • Park, Gye-Choon;Jung, Hae-Duk;Lee, Jin;Jeong, Woon-Jo;Kim, Jong-Uk;Cho, Young-Dae;Gu, Hal-Bon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.286-289
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    • 2001
  • Single phase CuGaS$_2$ thin film with the highest diffraction peak of (112) at diffraction angle (2$\theta$) of 28.8$^{\circ}$ was made at substrate temperature of 7$0^{\circ}C$, annealing temperature of 35$0^{\circ}C$ and annealing time of 60 min. And second highest (204) peak was shown at diffraction angle (2$\theta$) of 49.1$^{\circ}$. Lattice constant of a and c of that CuGaS$_2$ thin film was 5.37 $\AA$ and 10.54 $\AA$ respectively. The greatest grain size of the thin film was about 1${\mu}{\textrm}{m}$. The (112) peak of single phase of CuGaS$_2$ thin film at annealing temperature of 35$0^{\circ}C$ with excess S supply was appeared with a little higher about 10 % than that of no exces S supply And the resistivity, mobility and hole density at room temperature of p-type CuGaS$_2$ thin film with best crystalline was 1.4 $\Omega$cm, 15 cm2/V . sec and 2.9$\times$10$^{17}$ cm$^{-3}$ respectively. It was known that carrier concentration had considerable effect than mobility on variety of resistivity of the fabricated CuGaS$_2$ thin film, and the polycrystalline CuGaS$_2$ thin films were made at these conditions were all p-type.

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The Effects of Fuel Pellet Eccentricity on Fuel Rod Thermal Performance (핵연료의 편심이 연료봉 열적 성능에 미치는 영향)

  • Suh Young-Keun;Sohn Dong-Seong
    • Nuclear Engineering and Technology
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    • v.20 no.3
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    • pp.189-196
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    • 1988
  • This study investigates the effect of fuel pellet eccentricity on fuel rod thermal performance under the steady state condition. The governing equations in the fuel pellet and the cladding region are set up in 2-dimensional cylindrical coordinate (r, $\theta$) and are solved by finite element method. The angular-dependent heat transfer coefficient in the gap region is used in order to account for the asymmetry of gap width. Material propeties are used as a function of temperature and volumetric heat generation as a function of radial position. The results show the increase of maximum local heat flux at the cladding outer surface and the decrease of maximum and average fuel temperatures due to eccentricity. The former is expected to affect the uncertainties in the minimum DNBR calculation. The latter two are expected to reduce the possibility of fuel melting and the fuel stored energy. Also, the fuel pellet eccentricity introduces asymmetry in fuel pellet temperature and movement of the location of maximum fuel pellet temperature.

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