• Korean Journal of Optics and Photonics
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• v.30 no.4
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• pp.133-141
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• 2019

Revision of the International System of Units (SI) in terms of fundamental constants was achieved by the 26th General Conference on Weights and Measures (CGPM) in November 2018. Four base units (kilogram, ampere, kelvin, and mole) of SI were redefined by fixing the values of the Planck constant h, elementary charge e, Boltzmann constant k, and Avogadro constant $N_A$ respectively. In this paper the scientific principle for redefining the kilogram from the Planck constant with the Kibble balance is explained as an example. The revised SI takes effect on May 20, 2019.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.55-61
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• 2013

This paper compare the performance of S-MMA(Sliced-MultiModulus Algorithm) adaptive equalization algorithm by effect of slice weighting value for the minimization of the distortion and noise in the communication channel.. In the traditional MMA algorithm, the output signal of equalizer and the dispersion constant of transmitting signal is used for calculating the equalizer coefficient, but in S-MMA, the output of equalizer and dispersion constant and the considering the output of decision device by the power of slice constant are used in order to simultaneously compensate the distortion of amplitude and phase distortion. It is confirmed by computer simulation that the slice weighting value affects the performance of adaptive equalization algorithm. The performance index includes the output signal constellation, the residual isi and maximum distortion and MSE that is for the convergence characteristics, the SER according to the signal and noise power ratio at the channel is used. As a result of simulation, the residual isi, maximum distortion and MSE performances are better in the small weighting values. But in SER performance is better in the large weighting values.

• International Journal of Concrete Structures and Materials
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• v.7 no.3
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• pp.183-191
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• 2013

Prestress losses assumed for bridge girder design and deflection analyses are dependent on the concrete modulus of elasticity (MOE). Most design specifications, such as the American Association of State Highways and Transportation Officials (AASHTO) bridge specifications, contain a constant value for the MOE based on the unit weight of concrete and the concrete compressive strength at 28 days. It has been shown in the past that that the concrete MOE varies with the age of concrete. The purpose of this study was to evaluate the effect of a time-dependent and variable MOE on the prestress losses assumed for bridge girder design. For this purpose, three different variable MOE models from the literature were investigated: Dischinger (Der Bauingenieur 47/48(20):563-572, 1939a; Der Bauingenieur 5/6(20):53-63, 1939b; Der Bauingenieur, 21/22(20):286-437, 1939c), American Concrete Institute (ACI) 209 (Tech. Rep. ACI 209R-92, 1992) and CEB-FIP (CEB-FIP Model Code, 2010). A typical bridge layout for the Dallas, Texas, USA, area was assumed herein. A prestressed concrete beam design and analysis program from the Texas Department of Transportation (TxDOT) was utilized to determine the prestress losses. The values of the time dependent MOE and also specific prestress losses from each model were compared. The MOE predictions based on the ACI and the CEB-FIP models were close to each other; in long-term, they approach the constant AASHTO value. Dischinger's model provides for higher MOE values. The elastic shortening and the long term losses from the variable MOE models are lower than that using a constant MOE up to deck casting time. In long term, the variable MOE-based losses approach that from the constant MOE predictions. The Dischinger model would result in more conservative girder design while the ACI and the CEB-FIP models would result in designs more consistent with the AASHTO approach.

• Journal of the Korean Home Economics Association
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• v.11 no.4
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• pp.374-387
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• 1973

This work was carried out to investigate the changes of chemical and physical properties of frying oil, when it was used many times continuously without adding new oil. Four kinds of frying oil (soybean oil, rapeseed oil, shortening and crude lard) and slices of potato and Aji (kind of fish) were used in the experiment under the condition of home cooking. Obtained results were as in the followings. 1. Acid values and peroxide values of each frying oil were under the safety level (A. V = 1.5, Po. V = 50) except crude lard, when frying works were continuously repeated five times for 50 days. 2. Changes of saponification values of each frying oil showed a decreasing tendency except the crude lard. But in cases, stickiness or clothing of oil were not seen in frying even at the five times frying. 3. Changes of optical density of each frying oil showed a decreasing tendency in all cases, according to the times of frying, especially at the first time frying. 4. Maximum heights of the shamp of each frying oil and their shampholding activites when heated, were slowly increased according to the times of frying. 5. Without concerning the cooking condition (kinds of oil, cooking material and repeating times of frying) decrement of oil in once frying was almost exactly 20g per 150g. 6. Decrements of cooking material in all cases of frying showed almost constant values, potato to be 40% and Aji 20%. 7. Differences of smoke point between new and old oil (frying repeated 5 times) showed also almost constant values. Liquid oil (soybean oil and rapeseed oil) showed number (6-$10^{\circ}C$), on the contrally solid oil (shortening and crude lard) a high number (10-$25^{\circ}C$). 8. Results of public tastic for the frying products were almost good even in that of a low five times frying, but the products, of third time frying with crude lard were expressed as disagreeable.

• Korean Journal of Food Science and Technology
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• v.24 no.4
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• pp.301-305
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• 1992

Effect of heating medium and evaporation temperatures on a concentration ratio, a evaporation rate and a overall heat transfer coefficient during concentration of garlic juice by a centrifugal thin film evaporator were investigated. At constant feeding rate and evaporation temperature, the concentration ratio, the evaporation rate and the overall heat transfer coefficient increased with the increase of the steam temperature but those values increased slowly or decreased as a steam temperature exceeded $110^{\circ}C$. At the feeding rate of 50 kg/h and the steam temperature of $100^{\circ}C$ and below, those values decreased with the increase of evaporation temperature. But if a steam temperature became $100^{\circ}C$ and up, those values increased slowly and then decreased with the increase of the evaporation temperature until the evaporation temperature reached a critical value. At constant feeding rate, those values increased until the temperature difference between steam and evaporation temperatures became $70^{\circ}C$. But if they become larger than $70^{\circ}C$, those values increased slowly and then decreased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.636-639
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• 2000

Effects of sintering temperature and time on relative permittivity $\varepsilon$$\_$r/, unloaded quality factor Q$.$f and temperature coefficient of resonant frequency $\tau$$\_$f/ of dielectric resonator materials produced from commercial ZST powder were investigated in some detail. Q$.$f values, as determined from cavity perturbation method at 1.6 GHz, gradually increased with sintering temperature reaching the maximum at 1420$^{\circ}C$. However, bulk density and relative permittivity values, which increased with temperature, started to decrease above 1380$^{\circ}C$. In addition, Q$.$f values slightly increased with sintering time at the sintering temperature of 1300$^{\circ}C$∼1380$^{\circ}C$, while bulk density and relative permittivity values were approximately constant. It was also found that $\tau$$\_$f/ values were not affected by sintering temperature and time within the experimental conditions used.

• Journal of the Korean Ceramic Society
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• v.31 no.2
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• pp.201-205
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• 1994

Glasses being prepared, measurements and investigations of glass transition temperature and IR edge optical absorption have been performed for the compositions of 56ZrF4-14BaF2-6LaF3-4AlF3-(20-x)NaF-xLiF. Values for transition temperature of these glasses decrease in proportion to increasing LiF mol%(x) in the range of 0

• Proceedings of the IEEK Conference
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• 2003.11b
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• pp.19-22
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• 2003

Class area is a portion of memory where the constants, fields, and codes of the classes loaded into the Java virtual machine are kept. Knowing the site of the class area is very important especially for embedded Java system with limited memory resources. This paper induces a formula which makes it possible estimate the size of the area. The formula needs some constant values specific to target JVM implementation. We also show that these values can be found using some simple probe classes. An experimental result is included in this paper to confirm the correctness of our approach.

• KCI Concrete Journal
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• v.11 no.3
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• pp.45-52
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• 1999

A Computer-based iterative method is provided for the calculation of minimum thickness values for one-way slabs to satisfy the maximum permissible limits given in the ACI Building Code. An algorithm includes the effects of cracking and time-dependent effects due to creep and shrinkage. Comparison of the calculated minimum thickness values with the current ACI limits is conducted to investigate limitations of the current tabulated minimum thickness. which are constant to a range of design conditions.

• Journal of the Korean Ceramic Society
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• v.37 no.5
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• pp.511-515
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• 2000

The effect of Ba2+ ion dissolution with different pH and amount of PAA on microstructural changes of green and sintered bodies and its electrical properties was studied in aqueous nano-size BaTiO3 slurry system. The dissolution of Ba2+ was least at strong base, pH 10.8 and by addition of amount of 0.15 wt% PAA. The green body with the lowest of dissolution of Ba2+ at pH 10.8 and 0.15 wt% PAA had minimum values of average pore size, 40nm and shown high increase of sintered density. The compact sintered at 125$0^{\circ}C$ for 2 hr with highest Ba2+ dissolution had low density and dielectric constant due to abnormal grian growth. However, the sintered body with the lowest Ba2+ dissolution had high sintered density and then shown high dielectric constant.