• Clean Technology
• /
• v.25 no.3
• /
• pp.198-205
• /
• 2019

The adsorption equilibrium, kinetic, and thermodynamic parameters of brilliant green adsorbed by coconut based granular activated carbon were determined from various initial concentrations ($300{\sim}500mg\;L^{-1}$), contact time (1 ~ 12 h), and adsorption temperature (303 ~ 323 K) through batch experiments. The equilibrium adsorption data were analyzed by Langmuir, Freundlich, Temkin, Harkins-Jura, and Elovich isotherm models. The estimated Langmuir dimensionless separation factor ($R_L=0.018{\sim}0.040$) and Freundlich constant ($n^{-1}=0.176{\sim}0.206$) show that adsorption of brilliant green by activated carbon is an effective treatment process. Adsorption heat constants ($B=12.43{\sim}17.15J\;mol^{-1}$) estimated by the Temkin equation corresponded to physical adsorption. The isothermal parameter ($A_{HJ}$) by the Harkins-Jura equation showed that the heterogeneous pore distribution increased with increasing temperature. The maximum adsorption capacity by the Elovich equation was found to be much smaller than the experimental value. The adsorption process was best described by the pseudo second order model, and intraparticle diffusion was a rate limiting step in the adsorption process. The intraparticle diffusion rate constant increased because the dye activity increased with increases in the initial concentration. Also, as the initial concentration increased, the influence of the boundary layer also increased. Negative Gibbs free energy ($-10.3{\sim}-11.4kJ\;mol^{-1}$), positive enthalpy change ($18.63kJ\;mol^{-1}$), and activation energy ($26.28kJ\;mol^{-1}$) indicate respectively that the adsorption process is spontaneous, endothermic, and physical adsorption.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.9
• /
• pp.188-197
• /
• 2019

This study analyzed empirically the effects of the perception of outbound passengers, who flew from Korea to overseas tourist destinations, on the cabin service quality, tourist experience, and tourist satisfaction. For empirical analysis, a survey was given to Korean passengers using a national carrier of South Korea. Based on empirical analysis, the researchers judged that the analysis results and implications could be applied to inbound foreign passengers who visited Korea for the tourism purposes if researchers generated significant results from empirical analysis. This paper designed a research model that represented the meaningful relationship among, airline cabin-service quality, tourist experience, and tourist satisfaction following preceding research. According to the analysis, that factors that consisted of the cabin service quality had a significant effect on the tourist satisfaction with a mediating effect of both the cognitive and emotional tourist experience. Therefore, the perception on airline's cabin service quality of the national carrier would be a starting point that can help improve the tourist satisfaction.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.18 no.5
• /
• pp.126-141
• /
• 2019

One of the Cooperative Intelligent Transportation System(C-ITS) priority services is collision prevention support service. Several studies have considered V2I2V communication-based collision prevention support services using Artificial Neural Networks(ANN). However, such services still show some issues due to a low penetration of C-ITS devices and large delay, particularly when loading massive traffic data into the server in the C-ITS center. This study proposes the Artificial Neural Network-based Collision Warning Service(ACWS), which allows upstream vehicle to update pre-determined weights involved in the ANN by using real-time sectional traffic information. This research evaluates the proposed service with respect to various penetration rates and delays. The evaluation result shows the performance of the ACWS increases as the penetration rate of the C-ITS devices in the vehicles increases or the delay decreases. Furthermore, it reveals a better performance is observed in more advanced ANN model-based ACWS for any given set of conditions.

• Composites Research
• /
• v.32 no.5
• /
• pp.284-289
• /
• 2019

In the present paper, the dynamic force-moment equilibrium equations, driving power and energy equations are analyzed to formulate the equation for fuel economy(km/liter) equivalent to the driving distance (km) divided by the fuel volume (liter) of the vehicle, a selected model of gasoline powered KIA K3 (1.6v). In addition, the effects of the dynamic parameters such as speed of vehicle (V), vehicle total weight(M), rolling resistance ($C_r$) between tires and road surface, inclined angle of road (${\theta}$), as well as the aerodynamic parameters such as drag coefficient ($C_d$) of vehicle, air density(${\rho}$), cross-sectional area (A) of vehicle, wind speed ($V_w$) have been analyzed. And the possibility of alternative materials such as lightweight metal alloys, fiber reinforced plastic composite materials to replace the conventional steel and casting iron materials and to reduce the weight of the vehicle has been investigated by Ashby's material index method. Through studies, the following results were obtained. The most influencing parameters on the fuel economy at high speed zone (100 km/h) were V, the aerodynamic parameters such as $C_d$, A, ${\rho}$, and $C_r$ and M. While at low speed zone (60 km/h), they are, in magnitude order, dynamic parameters such as V, M, $C_r$ and aerodynamic ones such as $C_d$, A, and ${\rho}$, respectively.

• Convergence Security Journal
• /
• v.18 no.1
• /
• pp.117-128
• /
• 2018

The purpose of this paper is to analyze the behavior of North Korea's cyber attack against South Korea since 2009 based on major international security theories and suggest South Korea's policy option. For this purpose, this paper applied the behavioral domain and characteristics of 'cyber power' and 'coercion dynamics' model, which are attracting attention in international security studies. The types of cyber attacks from North Korea are classified into the following categories: power-based incarceration, leadership attacks and intrusions, military operations interference, and social anxiety and confusion. In terms of types and means of cyber power, North Korean GPS disturbance, the Ministry of Defense server hacking and EMP are hard power with high retaliation and threat and cyber money cashing and ransomware are analyzed by force in the act of persuasion and incentive in the point of robbing or asking for a large amount of money with software pawns. North Korea 's cyber attack has the character of escape from realistic sanctions based on the second nuclear test. It is important for South Korea to clearly recognize that the aggressive cyberpower of North Korea is changing in its methods and capabilities, and to ensure that North Korea's actions result in far greater losses than can be achieved. To do this, it is necessary to strengthen the cyber security and competence to simultaneously attack and defend through institutional supplement and new establishment such as cyber psychological warfare, EMP attack preparation, and enhancement of security expertise against hacking.

• Journal of Life Science
• /
• v.29 no.8
• /
• pp.888-894
• /
• 2019

Cartilage diseases, such as rheumatoid arthritis (RA) and osteoarthritis (OA), are associated with the loss of chondrocytes and degradation of articular cartilage. Recent studies revealed that inflammatory reactive oxygen species (ROS) and age-related oxidative stress can affect chondrocyte activity and cartilage homeostasis. We investigated changes in the levels of intracellular antioxidants during cellular senescence of primary chondrocytes from rat articular cartilages. Cellular senescence was induced by serial subculture (passages 0, 2, 4, and 8) of chondrocytes and measured using specific senescence-associated ${\beta}$-galactosidase ($SA-{\beta}-gal$) staining. ROS production increased significantly in the senescent chondrocytes. In addition, total glutathione (GSSG/GSH) and superoxide dismutase (SOD) levels and heme oxygenase-1 (HO-1) expression increased in senescent chondrocytes induced by serial subculture. Analysis of changes in intracellular antioxidant levels in articular cartilage from rats of different ages (5, 25, 40, and 72 wk) revealed that total glutathione levels were highest after 40 wk and slightly decreased after 72 wk as compared with those after 25 wk. SOD and HO-1 expression levels increased in accordance with age. Based on these results, we conclude that intracellular antioxidants may be associated with cartilage protection against excessive oxidative stress in the process of chondrocyte senescence and age-related cartilage degeneration in an animal model.

• Journal of Digital Convergence
• /
• v.17 no.9
• /
• pp.23-30
• /
• 2019

The development of content for language education using AR/VR technology is a necessary task to be pursued in line with commercialization of 5G. Research on service platform for systematic management and service is currently being carried out by global companies competitively, The unique language education service model for unique areas of culture has the right to pursue R & D jointly with Korea and China. In this study, we applied the developed "Korean language education service platform for Chinese people based on e-learning" to improve the acceptance of AR/VR contents and applied AR/VR technology to video-based language education contents. And to present a new paradigm of language education. Contents development is to develop AR-based vocabulary learning services, develop experiential learning contents for VR-based step-by-step situations, and gradually develop contents to enable beginner / intermediate / advanced language education services. The service platform enables management of learning management and learning contents, and complies with metadata attributes to complete a platform capable of accommodating large capacity AR/VR contents. In the future, systematic research will be carried out in order to develop as a portal for educational services through development of various contents using mixed reality technology.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.12
• /
• pp.872-877
• /
• 2018

STEAM is an acronym for Science, Technology, Engineering, Arts, and Mathematics. It is considered important to equip students with a creative thinking ability and the core competences required in future society, helping them devise new ideas emerging from branches of study. This study is about the convergence of instructional design in private finance for the life sciences, which aims to foster talent through problem-based learning (PBL). Skills like collaboration, creativity, critical thinking, and problem solving are part of any STEAM PBL, and are needed for students to be effective. STEAM projects give students a chance to problem-solve in unique ways, because they are forced to use a variety of methods to solve problems that pop up during these types of activities. The results of this study are as follows. First is the structured process of convergence lessons. Second is the convergence lesson process. Third is the development of problems in the introduction of private finance and the life sciences for a convergence lesson at Dornod University. Learning motivation shows the following results: understanding of learning content (66.6%), effectiveness (63.3%), self-directed learning (59.9%), motivation (63.2%), and confidence (63.3%). To make an effective model, studies applying this instructional design are to be implemented.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.6
• /
• pp.38-47
• /
• 2019

The purpose of this study was to identify latent classes in executive function difficulty of first graders depends on evaluations from their mother and teacher and to investigate how its related with their school adaption and academic performance in second grade. Based on the model of the latent profile analysis, the 8th and 9th wave data from Korean Children and Youth Panel Survey were analyzed. The results of this study were as following. First, results showed that there were three types of latent classes in the executive function difficulty depend on evaluations from their mother and teacher: 'low executive function,' 'students who were highly evaluated by mother,' and 'students who were highly evaluated by teacher.' Second, students' executive function difficulty had a direct effect on the students' school adaption and academic performance in their second year of school. Especially students who were evaluated as having the lowest executive function difficulty showed significant higher means than students who were evaluated higher by mother and teacher. This study emphasized the importance of multiple evaluation in students' executive function difficulty to provide an educational intervention.

• Journal of Digital Convergence
• /
• v.17 no.4
• /
• pp.159-166
• /
• 2019

This paper investigated convergent factors to turnover intention among some Administrative Staff in Medical Institutions(ASMI). The survey used self-administered questionnaires for 320 administrative staffs of 27 medical institutions in the J region, selected arbitrarily from July 2, 2018 to July 27, 2018. The hierarchical multiple regression analysis shows the following results. The turnover intention of respondents turned out to be significantly higher in following groups: a group in which organizational commitment is lower, a group in which organizational loyalty is higher, a group in which exhaustion, cynicism, reduced professional efficacy, sub-areas of job burnout are higher. The results show explanatory power of 50.9%. The results of the study indicate that the efforts, to increase organizational commitment and organizational loyalty, and to decrease exhaustion, cynicism, reduced professional efficacy, sub-areas of job burnout, are required to improve the turnover intention among ASMI. These results could be used in hospital organization personnel management and industrial health education to lower the level of turnover intention in ASMI, vocational aptitude education of health care college students. In following studies, it is necessary to present and analyze the structural model affecting the turnover intention of ASMI.