• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4602-4609
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• 2013

In summer and winter, the difference between the temperature during the day and that during the night is high, which leads to various problems during concrete placement, such as cracks and defects in the concrete as well as low durability and strength. Although nuclear power plant concrete is widely used for placement in all seasons, particular attention must be paid to its quality during the summer. Therefore, we evaluated the effects of a cooling method for mixing water, which is a commonly used hot weather precooling method, and the use of a retarder, on the characteristics of Nuclear Power Plant concrete. In the cooling method for mixing water, cold water at 5 was used, with 50% of the water content consisting of ice flakes. The effects of using a retarder were evaluated by reviewing the characteristics of the cement at the unset stage and after hardening. To evaluate the characteristics of the unset cement, we measured the slump, air volumes, setting times, and pressure strengths after hardening. Furthermore, we measured the heat of hydration at different temperatures; the loss of heat was minimized using insulation. Both the slump time and the complete ageing time of the air volume were found to be 120 min at $20^{\circ}C$ and 40 min at $40^{\circ}C$. In the case when the cooling method for mixing water was used and in the case when a retarder was used, the initial and final sets by penetration resistance were delayed, and the delay decreased with increasing air temperature. For the heat of hydration, the cooling method for mixing water not only lowered the maximum temperature but also delayed its attainment. However, the use of a retarder had no effect on the maximum temperature. Moreover, in the early ages (e.g., 3 and 7 days), the pressure strength of the concrete was lower than that of plain cement. However, the strength of 28-day concrete met the standard construction specifications.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.479-487
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• 2018

The purpose of this study is to analyze photochemical activity of nursery seedlings under drought stress, using chlorophyll fluorescence reaction analysis. Young nursery seedlings of tomato (Lycopersicon esculentum Mill.) and cucumber (Cucumis sativa L.), were grown under drought stress for 8 days. Analysis of chlorophyll fluorescence reaction (OJIP) and parameters, were performed to evaluate photochemical fluctuation in nursery seedlings under drought stress. Chlorophyll fluorescence reaction analysis showed maximal recorded fluorescence (P) decreased from the 5 day after treatment in tomato seedlings, while an amount of chlorophyll fluorescence increased at the J-I step. Thus, physiological activity was reduced. In cucumber seedlings, maximal recorded fluorescence (P) and maximal variable fluorescence ($F_V$) lowered from the 4 day after treatment, and chlorophyll fluorescence intensity of J-I step increased. Chlorophyll fluorescence parameter analysis showed electron transfer efficiency of PSII and PSI were significantly inhibited with decreasing $ET2_O/RC$ and $RE1_O/RC$ from the 5 day after treatment, in tomato seedlings and from the 4 day after treatment, in cucumber seedlings. $ET2_O/RC$ and $PI_{ABS}$ significantly changed. In conclusion, 6 indices such as $F_V/F_M$, $DI_O/RC$, $ET2_O/RC$, $RE1_O/RC$, $PI_{ABS}$ and $PI_{TOTAL}ABS$ were selected for determining drought stress in nursery seedlings. Drought stress factor index (DFI) was used to evaluate whether the crop was healthy or not, under drought stress. Cucumber seedlings were less resistant to drought stress than tomato seedlings, in the process of drought stress.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.1
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• pp.1-10
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• 2019

Purpose: The aim of this study was to evaluate the influence of polishing methods on the color stability of composite resins. Materials and Methods: Two bulk-fill and four conventional resin composites were filled in cylindrical molds (6 mm diameter, 4 mm height) and light-cured. The specimens were stored in $34^{\circ}C$ distilled water for 24 h. Spectrophotometer was used to determine the color value according to the CIE $L^*a^*b^*$ color space. Each group was divided into three groups according to polishing methods (n = 5). Group 1 was control group (Mylar strip group), group 2 was polished with PoGo, and group 3 was polished with Sof-Lex Spiral wheels. Color evaluation was performed weekly for 4 weeks after immersion in $34^{\circ}C$ distilled water. The results were analyzed by generalized least squares method (P < 0.05). Results: Generalized least squares analysis revealed that Sof-Lex Spiral wheels group showed the significantly lower ${\Delta}E$ values compared to PoGo and control group (P < 0.05). The ${\Delta}E$ values of polished group showed the significantly lower than the ${\Delta}E$ values of unpolished group (P < 0.05). Regarding color changes of composite resins, there was no significant difference between the ${\Delta}E$ values of Filtek Z250 and Filtek Z350 XT Universal restorative in all time intervals (P < 0.05). Tetric N-Ceram Bulk Fill showed the significantly lower ${\Delta}E$ values compared to other composite resins in 1, 2, 3 weeks (P < 0.05). Conclusion: Within the limitations of this study, polishing methods influence the color stabilities of composite resins. The group polished with Sof-Lex Spiral Wheels showed more resistance to discoloration than group polished with PoGo.

• Korean Journal of Labor Studies
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• v.23 no.1
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• pp.1-45
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• 2017

The aim of this study is to analyze the process of the struggle and bargaining for the change of the employment position of the irregular (in-house subcontracted) workers being at work in the Hyundai Motor Company (HMC) plants into the status of the regular employee of the company, and evaluate the results and limitation of the irregular workers' movement. Since the unionization of irregular workers in 2003, they have carried on the struggle against and the bargaining with the HMC, over the past 10 years and more, making claims for abolishing 'illegal temporary agency work' and for converting their positions into the regular ones. The HMC have gradually altered a confrontational stance against the workers' claim at the early stage, into the bargaining relationship with irregular workers' union. Eventually, the collective agreement on the 'special hiring' of about six thousands irregular workers by the HMC was reached in 2016. We attempt to analyze in depth the overall process by dividing three phases of the movement, according to the criteria of the relationship between the alliance and conflict system, and the cycle of protests of irregular workers. Furthermore, we try to trace the long and winding path of the movement, focusing on the cooperation/conflict relationship within the movement's alliance system, the confrontation/bargaining relationship between the movement and the conflict system, and the critical roles played by mediators (or third parties) between two systems. In the conclusion of the paper, we evaluate the results and limitation of the irregular workers' movement upon the basis of the following points; the convergence of the workers' demands into the prime goal of 'becoming HMC's regular employee,' the breakaway of regular workers' union from the movement's alliance system, and a virtual extinction of irregular workers' union after the final labor-management agreement of 2016.

• Applied Chemistry for Engineering
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• v.32 no.1
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• pp.117-123
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• 2021

In this study, the composite was prepared by mixing SiOx, soft carbon, and carbon black and the electrochemical properties of lithium ion battery were investigated. The content of SiOx added to improve the capacity of the soft carbon anode material was varied to 0, 6, 8, 10, 20 wt%, and carbon black was added as a structural stabilizer for reducing the volume expansion of SiOx. The physical properties of prepared CB/SiOx/C composite were investigated through XRD, SEM, EDS and powder resistance analysis. In addition, the electrochemical properties of prepared composite were observed through the charge/discharge capacity, rate and impedance analysis of the lithium ion battery. The prepared CB/SiOx/C composite had an inner cavity capable of mitigating the volume expansion of SiOx by adding carbon black. The formed internal cavity showed a low initial efficiency when the SiOx content was less than 8 wt%, and low cycle stability when the content of SiOx was less than 20 wt%. The CB/SiOx/C composite containing 10 wt% of SiOx showed an initial discharge capacity of 537 mAh/g, a capacity retention rate of 88%, and a rate of 79 at 2C/0.1C. SiOx was added to improve the capacity of the soft carbon anode material, and carbon black was added as a structural stabilizer to buffer the volume change of SiOx. In order to use the CB/SiOx/C composite as a high-efficiency anode material, the mechanism of the optimal SiOx and the use of carbon black as a structural stabilizer was discussed.

• Journal of the Korean Applied Science and Technology
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• v.38 no.3
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• pp.771-785
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• 2021

This study was performed to provide detailed and comprehensive information on inflammation-related blood indicators, joint range of motion, pain scale, and psychological indicators by patient characteristics by performing a 12-week home-based exercise program for ankylosing spondylitis patients. For the purpose of this study, 10 patients with ankylosing spondylitis were selected by age (30s vs. 40s vs. 50s), gender (male vs. female), and duration (less than 5 years vs. 5 years or more). The home-based exercise program was a combination of aerobic exercise and Pilates-based resistance exercise, and was performed 4 times a week for 12 weeks at an intensity of 50-70% of maximal heart rate (MHR). As a result, after 12 weeks of home-based exercise intervention, the blood C-reactive protein (CRP) concentration of patients with ankylosing spondylitis decreased (-35.6%, p=.002), and the blood inflammation level was improved, and each joint (hip, lumbar, cervical) improved mobility (p<.05). In addition, the bath ankylosing spondylitis disease activity index (BASDAI) was decreased by -67% (p=.001) and the visual analogue scale (VAS) was decreased by -64.8% (p=.001), stiffness and pain has been alleviated. In particular, as the degree of depression decreased by -65.5% (p=.001) and the degree of anxiety by -55.2% (p=.003), 12 weeks of home-based exercise improved not only physical changes but also psychological factors. On the other hand, there was no difference in exercise effect according to age, gender, and disease duration in ankylosing spondylitis patients (p>.05). These results suggest that the 12-week home-based exercise applied in this study can be an effective exercise program that can be universally used for ankylosing spondylitis patients regardless of patient characteristics.

• Journal of Plant Biotechnology
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• v.49 no.2
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• pp.118-123
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• 2022

To obtain information on the molecular mechanism underlying the low temperature tolerance of sweet potato [Ipomoea batatas (L.) Lam], the proteome expressed in the sweet potato cultivar Xushu 15-1 with high cold storage tolerance and in the cultivar Xushu 15-4 with low cold storage tolerance was analyzed using 2-D and MALDI-TOF/TOF analyses. Compared with the control (without cold treatment), four protein spots were newly expressed in Xushu 15-1. The expression level of one protein spot was higher in Xushu 15-4 than in Xushu 15-1. Spot 2, which was newly expressed in Xushu 15-1, was identified as sporamin. Assessment of the change in protein expression levels over 8 weeks in the storage roots of the two cultivars treated at 4℃ revealed no significant difference in the expression levels in Xushu 15-1 over time. However, in Xushu 15-4, the expression level of one protein spot increased, while those of four spots decreased. Of the proteins with reduced expression levels, spots 7 and 8 were identified as actin and spots 9 and 10 were identified as fructokinase-like proteins. The present results are expected to enhance the understanding of the complex mechanism underlying the low temperature tolerance of sweet potatoes during storage and can be used to identify candidate genes for the development of new varieties of sweet potatoes with improved low temperature tolerance during cold storage in the future.

• Journal of Korea Entertainment Industry Association
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• v.15 no.6
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• pp.35-54
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• 2021

This study examines the characteristics of CBS's Kim Hyun-Jung's News Show(hearafter News Show) and the change to transmedia. The distinguishing characteristics of News Show compared to radio-based current affairs programs are as follows. First, despite its time limit, it adopts the form of investigative reports or investigative documentaries to uncover the truth of the events through 'Detective Son Su-Ho', etc. Second, News show's interviews have avoided biased stance in the reporting of minority issues by interviewing the affected parties anonymously including people involved in incidents and accidents, bereaved families, and other victims. News Show has been producing a transmedia content called 'That Honey Show' (a show that reads comments as fun as honey) since November 2018. 'That Honey Show' is broadcast in real time on YouTube right after the News Show radio broadcast ends. As a form of spin-off content, 'That Honey Show' breaks down the boundaries among staff, MCs, and guests, as well as shifting roles by using 'vice characters'. The female host, Kim conducts interviews with the main characters related to various issues and extends the fixed identity of current affairs shows to the everyday politics and cultural realms. Thus she draws active participation and responses audience. This paper analyzes two representative broadcast cases of 'That Honey Show'-first, the case of resistance and activity of the BTS fandom ARMY in the US presidential election, and, second, the case of reporting on the Nth room incident. This analysis considers the critical participation of digital citizens and the effect of fostering a sense of community in the current affairs show in the transmedia era.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.2
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• pp.224-233
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• 1987

Most of the japonica rice varieties preferred for high eating quality are liable to lodging even under moderate rate of nitrogen application. This lodging liability has been a critical limit even for proper evaluation of physio-logical characteristics of those varieties exhibitable under higher nitrogen levels. Use of recent inhibitors of gibberellin biosynthesis such as ‘Pac1obutrazol’ may allow us to overcome this barrier. The responses of four high eating quality varieties to nitrogen application to the level of 150kg N per ha were evaluated with and without use of Paclobutrazol in comparison with a non-lodging, improved short japonica, Dongjin and a non-lodging, high yielding indica x japonica Milyang 23. The four were Damageum (the best eating quality in the 1930s), Nongrim 6 (the best in the 1960s), Chuchung (the best since 1970s), Koshihikari (the best in Japan since 1960s). As expected increased application of nitrogen increased plant height, length of the 3rd internode, and lodg-ing liability, being measured as culm breaking load, in all varieties tested and caused actual lodging in the fiel from the 50kg Nfha level in Damageum and Koshihikari and at the level of l50kg Nfha in Nongrim 6. Applica-tion of Pac1obutrazol (0.6%G) 15 days before heading reduced plant height, length of the 3rd internode and lodging liability being measured as culm breaking load in all varieties tested. However, the application of Pac1obutrazol during active tillering stage resulted in decreased culm breaking load in Damageum, Nongrim 6, and Koshihikari in spite of the decreased plant height and culm length as in the other varieties. Maximum yield was obtained with 100kg Nand 30kg Pac1obutrazol at 15 days before heading in Nongrim 6, 150kg N and 30kg Pac1obutrazol at 15 days before heading in Damageum, and 150kg N and 20kg Paclobutrazol at 20 days after transplanting plus 30kg Paclobutrazol at 15 days before heading in the variety Koshinhikari and Chuchung. Under a sensory evaluation of cooked rice, the four high eating quality varieties were not different in rank and Paclobutrazol treated rice was not distinguished from the untreated in eating quality.

• The Journal of Korean Philosophical History
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• no.27
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• pp.223-254
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• 2009

This thesis is aimed at researching the formation of democracy in socialist China. Due to a sense of cultural superiority on the basis of their developed civilization, they already formed a strong cultural nationalism, which has come to firm up into "Sinocentrism" through long periods of time. However, there arose a sense of crisis due to the Western invasion after the Opium War and the intellectuals in China happened to seek the solution to rescuing their mother land from ruin; in the midst of this process, the theory of social evolution of the West was introduced and accepted. The acceptance of this theory of social evolution gradually transformed in confrontation with a logical limit that China defeated in international competition could not but be plundered by imperialism after all, but it contributed to Chinese intellectuals' forming the concept of the modern state nationalism of the West deviating from cultural Sinocentrism. After the Russian Revolution, a large number of Chinese progressive intellectuals developed their socialist movement with the recognition that Marxism was a practicable alternative to rescue China from its crisis. The Chinese Communist Party was under guidance of the Comintern from the early process of its formation, in which they emphasized the fact the national liberation struggle in colonialized countries was an indispensable element in the world communist movement under the condition of the control of the world by imperialist capital at that time and subsequently, Marxism characterized by resistant nationalism in China gained its cause. Afterwards, the People's Republic of China was established by the Chinese Communists which came to get widespread support from the Chinese through anti-imperialism &feudalism in the process of the Sino-Japanese War, and thus China equipped with a full-blown socialism system set sails. However, with the relations with the Soviet Union getting worse under the international conditions of a cold war, the development of the Chinese socialism couldn't but resort to the concentrated power of its people, which was linked to the boost of continuous patriotism of the Chinese Communists. Particularly, due to the newly-emerging contradictions after reform & opening [gig kifng], China underwent disruption; thus, as an ideology to integrate such disruptive elements, Sinocentrism based on China's cultural pride re-appeared. Recently, a very strong form of Sinocentrism has come to the fore as their superiority of traditional cultures is emphasized in China whose international position as an economic power has been raised.