• Environmental and Resource Economics Review
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• v.19 no.1
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• pp.45-80
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• 2010

A computable general equilibrium model has been used to analyze the likelihood of double-dividend effect in Korean economy. Revenue neutral introduction of carbon tax through the reduction in payroll tax and corporate income tax had been experimented in this regard. Double-dividend measured by income shows the existence of weak double-dividend in both cases, while double-dividend measured by consumption level could not be found in case of carbon tax with corporate income tax reduction. A notable result is in the employment measured double-dividend effect as the sizable strong double-dividend effect were found in the case of carbon tax with payroll tax reduction.

• Magazine of the Korean Society of Agricultural Engineers
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• v.30 no.2
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• pp.82-94
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• 1988

The purpose of this study is to introduce the Double Punch test method which is an indirect testing method of tensile strength of concrete, and to compare with the tensile strength of concrete as determined by the split-cylinder test, a practical method for performing the Double Punch test to obtain the tensile strength of concrete is proposed and recommended for general use. In this study, the dimensions of cylindrical specimens used in the Double-Punch test were 15X30cm, 15X15cm, 10${\times}$(20cm, and 5${\times}$l0cm, and in the split-cylinder test were 15${\times}$(30cm, 15${\times}$(15cm, and 10${\times}$(20cm. And the diameters of loading punches used in the Double-Punch test were 1.5cm, 2.5cm, and 3.5 cm. The results obtained from tests are summarized as follows ; 1. In the split-cylinder test, the tensile strength of concrete by the linear elasticity theory is similar to that of plasticity theory. 2. Both split-cylinder test and Double-Punch test, tensile strength of concrete is increased with decreasing specimen size. This tendency is identical when the ratio of specimen diameter to height is 1: 2, but that tendency is quite different when the ratio is 1: 3. In the Double-Punch test, if specimen size is constant, by increasing the punch size, tensile strength of concrete is increased, too. 4. Using a 15 ${\times}$( 15 cm cylinder specimen and 3.5 cm diameter punch in the Double Punch test would give the most uniform and consistent result in tensile strength, and the result showed a gQod correlation with splitting tensile strength from 15 x 30cm specimen. 5. In order to obtain satisfactory results and to nuninuze variability, it is proposed that specimens of 15 cm in diameter and 15 cm in height with two 3.5 cm diameter punches should be used. It seems, therefore, reasonable tt) take f't=0.0024 P(kg / cm$^2$) as a working formula for computing the tensile strength in the Double Punch test for concrete.

• Food Science of Animal Resources
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• v.35 no.2
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• pp.248-257
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• 2015

Effects of double packaging (combinational use of aerobic and vacuum conditions) and antioxidants on physicochemical properties in irradiated restructured chicken rolls were determined. Chicken breast treated with antioxidants (none, sesamol+a-tocopherol) was used to process restructured chicken breast rolls. The sliced rolls were vacuum, aerobic, or double packaged (vacuum for 7 d then aerobic for 3 d) and electron beam irradiated at 2.5 kGy. Color, 2-thiobarbituric acid reactive substances (TBARS), oxidation reduction potentials (ORP), and volatile profiles of the samples were determined at 0 and 10 d. Irradiation made restructured chicken rolls redder (p<0.05), and the increased redness was more distinct in irradiated vacuum-packaged than irradiated aerobic or double packaged meats. TBARS values of antioxidant-treated double packaged rolls were lower than even nonirradiated vacuum-packaged meat, and those were distinct at 10 d (p<0.05). ORP and lipid oxidation values were lower in irradiated vacuum and double packaged samples than those in irradiated aerobic packaged ones at 0 d (p<0.05). Irradiation of restructured chicken rolls increased the amount of total volatiles. Considerable amounts of off-odor volatiles were reduced or not detected by double packaging and antioxidant treatment at 10 d. Therefore, the combined use of antioxidants and double packaging would be useful to reduce redness and control the oxidative quality changes of irradiated restructured chicken rolls

• Journal of the Korea Institute of Building Construction
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• v.14 no.6
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• pp.571-581
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• 2014

In the present study, hollow precast concrete wall (PC Double Wall) for staircase construction was developed. Comparing the conventional walls, the PC Double Wall can be reduced the lift weight using hollow core and improves the integrity between the PC members. The cross-section and re-bar details of the PC Double Wall were developed considering precast concrete manufacturing, constructability, and the structural safety. Particularly, a form system was developed to manufacture thin and hollow core PC wall efficiently. A mock-up test for a staircase using the PC Double wall was performed to verify the constructability and integrity of the PC walls. The test result verified that joint deformation and cracking did not occur as showing good constructability.

• Education of Primary School Mathematics
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• v.22 no.1
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• pp.29-48
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• 2019

Previous studies on double scale models, visual models with two different scales (Chong, 2015), have focused on double number line and little research has been conducted on how to employ double scale models in the elementary mathematics textbooks series. Given this, we analyzed the characteristics of double scale models in the Japanese elementary mathematics textbooks in the following aspects: (a) the contents of units where double scale models were used; (b) the purposes of using such models; (c) the types of such models tailored to the contents and grade levels; and (d) the characteristics of problem contexts dealing with the models. The results of this study showed that double scale models were effectively used to connect the contents related to multiplication, specifically for the contexts of ratio. Such models were addressed for students in a systematic and gradual way as the grade levels went up. Based on these results, this paper describes implications on how to use double scale models in mathematics textbooks.

• Journal of Korea Game Society
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• v.19 no.4
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• pp.49-64
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• 2019

In this paper, we examined the concept of three types of double loot box respectively and analyzed each characteristics of double loot box by game case study. Those types are divided into the following three cases; 1) Double-mileage gacha 2) Double-limited period gacha 3) Kompu gacha. As the result, Double loot boxs are characterized as below: 1) Double loot box has a tendency to combine various type of loot boxes. 2) Double loot box's reward is hard to gain in game, or not to sell in game store. With these features, double loot box could be a gambling sales strategy. To solve this problem, this study suggested that it is essential to revise game self-regulations, enhance the professionalism of monitoring groups, and propel the self-effort of game companies.

• KIEAE Journal
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• v.15 no.3
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• pp.43-48
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• 2015

Purpose: Recently, many countries around the world are actively looking for the ways to make full use of natural energy sources and also develop and apply an environmentally friendly system designed to save building energy consumption. Under these circumstances, this study intended to determine the applicability and energy saving effect by deriving the indoor thermal performance characteristics and the PCM temperature appropriate for a double skin façade to reduce indoor energy consumption through the application of different PCM temperatures to double skin façade and perform a performance evaluation depending on the application or non-application of PCM to a double skin façade. Method: For this study, the physical variables of the double skin façade with PCM were configured through a preliminary examination based on an experimental measurement, and experimental measurements were taken with a total of 7 types of mockup cases: Type-1 (Basic), the basic double skin façade, Type-2 (PCM $18^{\circ}C$) which was applied to the inner skin of the double skin façade depending on the phase-change temperature of PCM, Type-3 (PCM $20^{\circ}C$), Type-4 (PCM $22^{\circ}C$), Type-5 (PCM $24^{\circ}C$), Type-6 (PCM $26^{\circ}C$), and Type-7 (PCM $28^{\circ}C$) with reference to the data analysis of the basic double skin façade which preceded this study, to analyze the indoor thermal performance of the double skin façade depending on PCM temperature and the installation or non-installation of a double skin façade applying PCM based on the selected unit space. Result: Indoor thermal performance was analyzed depending on the PCM temperature applicable to double skin façade, and the analysis of heating energy reduction showed that Type-2 (PCM $18^{\circ}C$) gained 15.9% more heat compared with Type-1 (Basic) and secondly, Type-3 (PCM $20^{\circ}C$) gained 11.5% more heat. Based on these findings, it is deemed possible that the use of energy for heating can be reduced when heat coming indoors increases during the heating period, and the appropriate temperature for PCM applied to the inner skin of a double skin façade to reduce heating energy in winter, Type-2 (PCM $18^{\circ}C$) showed the highest efficiency and Type-3 (PCM $20^{\circ}C$) was also deemed appropriate.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.4
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• pp.249-256
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• 2019

A full-scale test line was established to verify the electrical environmental interferences caused by the HVDC ±500 kV Double Bipole overhead transmission line with metallic return conductor, which is scheduled for construction in Korea and the fullscale test was conducted for one year. And through the human perception test of the DC electric-field under the HVDC Double Bipole line, the threshold value at which the human detects DC electric field was investigated to verify the validity of the design guide for the HVDC ±500 kV Double Bipole overhead transmission line. The polarity configuration of the HVDC ±500 kV Double Bipole test line was arranged diagonally with the same polarity in terms of the electrical environment disturbance and operation. The test line utilized the 6-bundle arrangement to prevent the corona discharge taking into account the domestic social acceptability. The test results show that the HVDC ±500 kV Double Bipole transmission line generated very little corona discharge from the conductors. Therefore, both DC electric field and ion current density met the domestic design guide for DC overhead transmission lines. Also, the human perception test of DC electric fields under the test line showed that 70% of participants did not recognize the DC electric field even when exposed to 23 kV/m.

• Journal for History of Mathematics
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• v.20 no.3
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• pp.1-16
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• 2007

In order to generalize theory of series in Iksan(翼算), we introduce a concept of double sequence of partial sums and elementary double sequence of partial sums, which play a dominant role in the study of double sequences of partial sums. We introduce a concept of finitely generated double sequence of partial sums and find a necessary and sufficient condition for those double sequences. Finally we prove a multiplication theorem for tetrahedral numbers and for 4 dimensional tetrahedral numbers.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.749-755
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• 2023

A new approximation method was proposed for treating the non-resonant spatial self-shielding effects of double heterogeneous region such as the double heterogeneous effect of VHTR fuel compact in the thermal energy range and that of BP compact with BISO. The method was developed based on the effective homogenization method and a spherical unit cell model with explicit coated layers and a matrix layer. The self-shielding factor was derived from the relation between the collision probabilities for a double heterogeneous compact and the effective cross section for the homogenized compact. First, the collision probabilities and transmission probabilities for all layers of the spherical model were calculated using conventional collision probability solver. Then, the effective cross section for the homogenized sphere cell representing the homogenized compact was obtained from the transmission probability calculated using the probability density function of a chord length. The verification calculations revealed that the proposed method can predict the self-shielding factor with a maximum error of 2.3% and the double heterogeneous effect with a maximum error of 200 pcm in the typical VHTR problems with various packing fractions and BP compact sizes.