• Applied Chemistry for Engineering
• /
• v.33 no.5
• /
• pp.459-465
• /
• 2022

A pitch coating method was proposed for the purpose of improving the electrochemical properties of natural graphite. The synthesis conditions of pitch coating were optimized via measuring electrochemical properties of pitch-coated graphite anodes. As the synthesis temperature increased, the thermal stability was improved in addition to an increase in the softening point and residual carbon weight. However, the synthesis temperature of 430 ℃ resulted in the synthesis of a large amount of NI (NMP Insoluble) due to excessive condensation reaction. As the surface uniformity and coating thickness increased due to high thermal stability, the initial coulombic efficiency and rate capability of the pitch-coated graphite were improved. However, the graphite coated with the pitch containing excessive NI showed lower electrochemical properties than the uncoated graphite. NI had low dispersibility and formed spheres after heat treatment, so it formed the heterogeneous and thicker SEI layer. The optimum conditions for forming a uniform surface and an appropriate coating layer were investigated.

• Korean Journal of Ecology and Environment
• /
• v.55 no.4
• /
• pp.376-389
• /
• 2022

Despite the consumption of disinfectants have been increased by COVID-19 pandemic, the fate of the chemicals in aquatic food webs are still unclear. In order to understand the trophic transfer of the chemicals, the concentration of disinfectants including six benzalkonium chloride (BACs) and five didecyldimethylammonium chlorides(DDACs) were measured at the Geum (2020), Han (2021), and Yeongsan River (2021), before and after rainfall. The highest concentration of ∑BACs (mainly C12 and C14) and ∑DDACs (mainly C10 and C14) were observed in the Han River, followed by Yeongsan River, Geum River Estuary, and Gapcheon. After rainfalls, both concentration and detection frequency were decreased in all sites. Although the BAC and DDAC seems to be accumulated in organisms, they were bio-diluted rather than magnified in the aquatic food web with the biomagnification factor(BMF) of less than 1, trophic magnification slope (TMS) from -0.236 to 0.001, and trophic magnification factor(TMF) from 0.85 to 1.01.

• Korean journal of communication and information
• /
• v.55
• /
• pp.164-183
• /
• 2011

Technology innovation of digital convergence in recent years of the media sector has produced a series of significant changes in journalist labor. This study analyzes how recent introduction of convergent newsroom changed the nature of journalist labor and what strategy the management used to control journalists within the technologically innovated working condition with case of CBS. As the labor process theory tells us, the analysis found that technological innovation in the newsroom has encouraged a couple of aspects regarding labor process. First, losing control over their own labor journalists have undergone the process of significant deskilling. Second, the management have made a constant effort to introduce ideological and political apparatuses with twofold purposes, effective control over workers on one hand and concealing oppressive labor conditions on the other. The effort generated journalists' acceptance of new news-making routine and their consent on labor-management culture founded upon naive familism, which at last resulted in reinforcement of corporate power and isolation of labor society by separating internal labor market.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.7 no.5
• /
• pp.1180-1197
• /
• 2013

Network coding is one of the most promising techniques to increase the reliability and reduce the energy consumption for wireless sensor networks (WSNs). However, most of the previous works mainly focus on the network coding for multicast or unicast in WSNs, in spite of the fact that the converge-cast is the most common communication style in WSNs. In this paper, we investigate, for the first time as far as we know, the feasibility of acquiring network coding benefits in converge-cast, and we present that with the ubiquitous convergent structures self-organized during converge-casting in the network, the reliability benefits can be obtained by applying linear network coding. We theoretically derive the network coding benefits obtained in a general convergent structure, and simulations are conducted to validate our theoretical analysis. The results reveal that the network coding can improve the network reliability considerably, and hence reduce number of retransmissions and improve energy-efficiency.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.23 no.8
• /
• pp.543-548
• /
• 2011

New concept of wind energy conversion system is proposed to increase the energy density at a given working space. The quality of wind for wind power generation is depend on its direction and speed. However, the quality is not good on land because wind direction is changeable all the time and the speed as well. The most popularly operated wind turbine system is an axial-flow free turbine. But its conversion efficiency is less than 30% and even less than 20% considering the operating time. In this research, a cross-flow type wind turbine system is proposed with a convergent-divergent duct system to accelerate the low speed wind at the inlet of the wind turbine. Inlet guide vane is also introduced to the wind turbine system to have continuous power generation under the change of wind direction. In here, the availability of wind energy generation is evaluated with the change of the size of the inlet guide vane and the optimum geometry of the turbine impeller blade was found for the innovative wind power generation system.

• Polymer Science and Technology
• /
• v.21 no.5
• /
• pp.447-458
• /
• 2010

• Journal of Mechanical Science and Technology
• /
• v.15 no.12
• /
• pp.1829-1834
• /
• 2001

The choking of dual subsonic streams flowing through a convergent duct in contact has been investigated experimentally and theoretically. The experiment was conducted by using blow-down wind tunnel. The condition, when the dual stream flow chocking (compound choking) occurs at the nozzle exit, was explained by one-dimensional analysis of compound sound wave propagation. The experimental results for the condition of compound choking were compared with the prediction from theoretical analysis, and the schlieren optical method using the spark light source has been used to visualize the flowfield.

• Structural Engineering and Mechanics
• /
• v.9 no.2
• /
• pp.153-168
• /
• 2000

This paper presents four incompatible but convergent Rational quadrilateral elements, two four-node elements (RQ4Z and RQ4B) and two five-node elements (RQ5Z and RQ5B). The difference between the so-called Rational Finite Element (Zhong and Zeng 1996) and the Free Formulation (Bergan and Nygard 1984) are discussed and compared. The importance of the mode completeness in these formulations is emphasized. Numerical results for several benchmark problems show the good performance of these elements. The two five-nodes elements RQ5Z and RQ5B, which can be viewed as complete quadratic mode elements (with seven stress modes), always give better results than the four nodes elements RQ4Z and RQ4B.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
• /
• v.5 no.4
• /
• pp.683-691
• /
• 2015

The purpose of this paper is to determine the actual strategies used in Inventory Management in the field of Distribution phenomenon. In the first part of the research, theoretical backgrounds will be reviewed in order to provide better understanding the importance of Inventory Management in Distribution Management. The qualitative data were gathered by face to face interviews and a phone interview from four selected intermediaries. The study finds intermediaries practicing JIT in the sales and distribution and maximizing the sales activities and minimizing the inventory cost by giving up on an opportunity cost.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
• /
• v.8 no.11
• /
• pp.31-40
• /
• 2018

This paper studies how marriage migrants are being depicted in Korean Cinema. In the recent years, the foreign population in South Korea has been increasing and so has done the presence of migrant minorities in media, including cinema. This study discusses that korean cinema shows dominant ideologies of power in Korean society where marriage migrants are located at the bottom. Five films were analyzed and from this analysis five frames were extracted. Marriage migrants are frequently depicted as subordinated or powerless, they are usually women in the role of wives, mothers, and daughters-in-law, they are treated as ethnic others, sexualized others or commodities. Consequently, their relationships with Korean nationals are formed by power relations. Moreover, Korean national who do establish some sort of intimate relationship with the marriage migrants are represented as people in the margins of Korean society. In this way, it is reinforced the social position of marriage migrants as outsiders in the Korean society.