• Environmental and Resource Economics Review
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• v.29 no.4
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• pp.499-520
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• 2020

Input ratio of electricity to other production inputs in the Korean manufacturing sector has been higher than for the other OECD countries. In addition, electricity prices in Korea has been relatively lower than the average of OECD countries. Moreover, electricity sector is responsible for most CO2 emissions in Korea as coal and natural gas account 41.9% and 26.8% of electricity production as of 2018. Therefore, it looks inevitable to raise the electricity tariff for the manufacturing sector in Korea, but there is a concern that increase in the electricity tariff might affect small and medium enterprises (SMEs) more than large firms. This study estimates electricity demand's price and output elasticities for large firms and SMEs in steel industry by employing a time varying parameter model (Kalman filter). The analysis shows that changes in output levels regardless of firms' size affect electricity demands more significantly than do changes in electricity prices. Second, large firms have higher variances for both price and output elasticities of electricity demand. Third, large firms have higher price elasticity but lower output elasticity of electricity demand relative to SMEs. Policy implications are suggested in association with how to reduce electricity demands in the energy-intensive industry.

• Journal of the Korea Convergence Society
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• v.12 no.3
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• pp.107-114
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• 2021

The purpose of this study is to investigate whether there is a difference in the effect of learning flow and teaching presence according to the lecturer's appearance and students' behavioral patterns in video learning. For this experiment, 183 freshmen from Xingtai University in China were selected as subjects. After being classified according to DISC, students were assigned to study the lecture videos with the appearance of the lecturer and the video without the appearance of the lecturer. After testing the level of their learning flow and teaching presence, the differences between groups were analyzed. According to the results of the analysis, the learning flow and teaching presence of groups who learned the videos in which the lecturer appeared were significantly higher than the groups who learned the videos without the appearance of the lecturer. Second, the effects of whether the lecturer appears or not according to DISC on learning flow were significant. However, the effects of DISC, and the interactive effect of DISC and the lecturer appearance were found to have no significant interactive effect on learning flow. Third, the effects of whether the lecturer appears or not according to DISC on teaching presence were significant, and the effects of DISC on teaching presence were not significant, but the interactive effect of lecturer appearance and DISC was significant. These findings suggest that lecture videos with the appearance of the lecturer generally have better effect. In particular, in order to enhance teaching presence, it is effective to decide whether the lecturer appears or not by considering its interactive effects with learners' DISC.

• Journal of Korean Medicine for Obesity Research
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• v.20 no.2
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• pp.138-148
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• 2020

Objectives: The aim of this study is to evaluate the effects of Bangpungtongseong-san (Fangfengtongsheng-san, BTS) and Daesiho-tang (Dachaihu-tang, DST) on weight loss and improvement in lipid metabolism and glucose metabolism. Furthermore, we intend to develop a prediction model for drug effects through the analysis of the single nucleotide polymorphism (SNP), gut-microbiota, and the expression of immune-related biomarkers. Methods: This study is a single-center, randomized, double-blind, parallel-design clinical trial. One hundred twenty-eight participants will be assigned to the BTS group (n=64) and DST group (n=64). Both groups will be administered 4 g medication three times a day for up to 2 weeks. The primary outcomes is weight loss. The secondary outcomes include bioelectrical impedance analysis, waist circumstance, body mass index, total cholesterol, high-density lipoprotein, triglyceride, insulin resistance. The exploratory outcomes include 3-day dietary recall, food frequency questionnaire, quality of life questionnaire, gut microbiota analysis, immune biomarkers analysis, and SNP analysis. Assessment will be made at baseline and at week 4, 8, and 12. Conclusions: This protocol will be implemented by approval of the Institutional Review Board of Dongguk University. The results of this trial will provide a systematic evidence for the treatment of obesity and enable more precise herbal medicine prescriptions.

• Journal of Mushroom
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• v.19 no.2
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• pp.96-102
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• 2021

A new cultivar of oak mushroom 'Dadam' was bred from monokaryotic strains of 'GMLE36062-4' and 'GMLE36288-34'. The optimum temperature for mycelial growth of the new cultivar 'Dadam' on potato dextrose agar was 19-22℃. Total cultivation period of the new cultivar, from innoculation to its first harvest, was 135-139 days, similar to that of the control cultivar 'Hwadam'. The pileus color and stipe thickness of the new cultivar were darker and thinner than those of 'Hwadam'. Total yield of 'Dadam' was 621 g per 3 kg substrate, and is higher than that of 'Hwadam' (371 g). In farmhouse field test, it showed that the period of mycelial growth, browning, and fruiting body formation were the same as those of the control cultivar L808. The number of available fruiting bodies of 'Dadam' was 15, and is lower than that of the control (47), therefore, it was possible to save workforce in thinning. The total yield for 2 flush was 480 g for 'Dadam', similar to the 473 g of the control cultivar.

• Journal of Korea Foundry Society
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• v.41 no.3
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• pp.235-240
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• 2021

We present the effect of the critical cooling rate during rapid solidification on the nucleation of precipitates in an Fe₇₅B₁₃P₅Nb₂Hf₁C₄ (at.%) alloy. The thermophysical properties of the rapidly solidified Fe₇₅B₁₃P₅Nb₂Hf₁C₄ liquids, which were obtained at various cooling rates with various sizes of gas-atomized powder during a high-pressure inert gas-atomization process, were evaluated. The cooling rate of the small-particle powder (≤20 ㎛) was 8.4×10⁵ K/s, which was 13.5 times faster than that of the large-particle powder (20 to 45 mm; 6.2×10⁴ K/s) under an atomized temperature. A thermodynamic calculation model used to predict the nucleation of the precipitates was confirmed by the microstructural observation of MC-type carbide in the Fe₇₅B₁₃P₅Nb₂Hf₁C₄ alloy. The primary carbide phase was only formed in the large-particle gas-atomized powder obtained during solidification at a slow cooling rate compared to that of the small-particle powder.

• Journal of Korean Society of Forest Science
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• v.100 no.3
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• pp.466-475
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• 2011

This study purposed to analyze the spatial pattern and the amount of carbon emission at the deforestation area based on the administrative and GIS data. The total size of deforestation area in last nine years (2000-2008) was about 649 ha, and it was occurred annually about 72 ha. The occurrence rate of deforestation per administrative area in Wonju was about 0.74%. It was 0.34% higher than that of Kwangwondo, and 0.06% less than that of National rate. On the other hand, the forms of deforestation by purpose were not related to the administrative district unit. The number of deforestation forms was highest at settlements. second most frequent form is other land. Grassland showed the lowest score. In addition, the deforestations were more occurred which is closed to the existing housing and building rather than roads. The number of deforestation was 1.2 times higher based on 300m. Seventy percent of deforestation was occurred which is less than 0.5 ha in size, and it increased to 91% when the size is less than 1ha. The total size of theoretical carbon emission based on deforestation area was estimated at 23,424 tc, and average annual carbon emission was estimated by 2,603 tc. Carbon emission per ha was 36.1 tC/ha. This study results will be useful to construct the greenhouse gas statistical verification system against the Post-2012 by GIS.

• 한국노년학
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• v.36 no.4
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• pp.1141-1155
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• 2016

The purpose of this study was to compare the preventive effects of green tea and coffee drinking on postprandial hypotension in the elderly. A total of 30 women ($81.2{\pm}6.8years$) who had experience of postprandial hypotension participated 3 interventions by random order allocation. During the experimental interventions, each participant had a cup of instant coffee (60mg caffeine), or green tea (15.8mg caffeine) after lunch, and control group had only their lunch. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were measured with 15 minute interval from 30 minutes before the meal to 120 minutes after the meal. The preprandial SBP and DBP were not significantly different between three groups. Postprandial SBP reduction measured at the 1 hour after meal was significantly smaller in coffee group compared to the control group, whereas green tea group was not ($-15.1{\pm}17.9mmHg$ vs $-13.4{\pm}22.4mmHg$ vs. $-4.1{\pm}18.6mmHg$ for control, green tea, and coffee group, respectively, p=.032). Likewise, DBP decrement at the 1 hour after meal was significantly smaller in coffee than control group ($-12.8{\pm}13.0mmHg$ vs $-6.9{\pm}16.6mmHg$ vs $-0.8{\pm}13.4mmHg$ respectively, p=.033). The HR response of the three groups were not significantly different throughout the intervention. Coffee drinking was potentially beneficial for preventing postprandial hypotension and resultant falling event.

• The Journal of Korean Philosophical History
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• no.50
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• pp.363-389
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• 2016

Any moral ideas get integrity upon their practices. Because in human society systems, morality have capability among human interactions, for it gives moral standards(good or bad/ right or wrong) to them. And when the society system is Korean, Koreans surely have developed unique styles of moral practice and moral education in their traditional ages. So reinterpretating and categorizing the moral tradition for taking advantage of it in contemporary context, make sense. In this study, Korean moral tradition is focused in its scope, as 'Confucian moral tradition in semi-modern era'. For convenience of study and the potentials of effective revision, Korean tradition have been resized. In Confucian moral tradition, semi-modern Korean moral ideas could be presented as ren(仁) and yi(義). Furthermore, ren and yi could be practiced with several moral virtues, like xiao(孝), di(弟), ci(慈), zhi(直) qin(勤) gian(儉). When compared with contemporary moral education idea systems, the traditional system can have affinity with the systems in moral ideas division('with-self morality', 'with-others morality', 'with-universe and transcendence morality'). And several fusion-style, integration-based education practices can be developed and applied at contemporary school moral education.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.11 no.1
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• pp.13-23
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• 2001

This paper implemented into hardware SEED which is the KOREA standard 128-bit block cipher. First, at the respect of hardware implementation, we compared and analyzed SEED with AES finalist algorithms - MARS, RC6, RIJNDAEL, SERPENT, TWOFISH, which are secret key block encryption algorithms. The encryption of SEED is faster than MARS, RC6, TWOFISH, but is as five times slow as RIJNDAEL which is the fastest. We propose a SEED hardware architecture which improves the encryption speed. We divided one round into three parts, J1 function block, J2 function block J3 function block including key mixing block, because SEED repeatedly executes the same operation 16 times, then we pipelined one round into three parts, J1 function block, J2 function block, J3 function block including key mixing block, because SEED repeatedly executes the same operation 16 times, then we pipelined it to make it more faster. G-function is implemented more easily by xoring four extended 4 byte SS-boxes. We tested it using ALTERA FPGA with Verilog HDL. If the design is synthesized with 0.5 um Samsung standard cell library, encryption of ECB and decryption of ECB, CBC, CFB, which can be pipelined would take 50 clock cycles to encrypt 384-bit plaintext, and hence we have 745.6 Mbps assuming 97.1 MHz clock frequency. Encryption of CBC, OFB, CFB and decryption of OFB, which cannot be pipelined have 258.9 Mbps under same condition.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.10 no.4
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• pp.81-93
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• 2000

In a methodological approach to improve the processing performance of modulo exponentiation which is the primary arithmetic in RSA crypto algorithm, we present a new RSA hardware architecture based on high-radix modulo multiplication and CRT(Chinese Remainder Theorem). By implementing the modulo multiplier using radix-16 arithmetic, we reduced the number of PE(Processing Element)s by quarter comparing to the binary arithmetic scheme. This leads to having the number of clock cycles and the delay of pipelining flip-flops be reduced by quarter respectively. Because the receiver knows p and q, factors of N, it is possible to apply the CRT to the decryption process. To use CRT, we made two s/2-bit multipliers operating in parallel at decryption, which accomplished 4 times faster performance than when not using the CRT. In encryption phase, the two s/2-bit multipliers can be connected to make a s-bit linear multiplier for the s-bit arithmetic operation. We limited the encryption exponent size up to 17-bit to maintain high speed, We implemented a linear array modulo multiplier by projecting horizontally the DG of Montgomery algorithm. The H/W proposed here performs encryption with 15Mbps bit-rate and decryption with 1.22Mbps, when estimated with reference to Samsung 0.5um CMOS Standard Cell Library, which is the fastest among the publications at present.