• Journal of the Korean Society of Tobacco Science
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• v.26 no.2 s.52
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• pp.126-134
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• 2004

Tobacco dust samples were collected for two times in primary and secondary process at 4 cigarette manufacturing factories(Shintanzin, Youngju, Wonju, Kwangju) and analyzed to evaluate usage as a raw material in production of reconstituted tobacco. The chemical constituents and HWS of tobacco dust were analyzed. Tobacco dust samples were partitioned by particle size using a series of screens ranging from 20 to 200 mesh. The amount of material retained in each fraction was quantified and sand content was also determined. Appreciable average amounts$(40-65\%)$ material at 4 locations were found to be larger than 60 mesh. Although the amount of material in each fraction increased to a maximum at 100 mesh and then decreased, the $\%$ sand continually increased with decreasing particle size. The chemical constituents and HWS content of tobacco dust have similar values in secondary process of 4 cigarette manufacturing factories but the those of primary process have different values according to the site of occurrence and manufacturing factories.

• Journal of Digital Convergence
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• v.16 no.4
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• pp.321-327
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• 2018

Applications have evolved with the evolution of smartphones, and the search structure is changing as well. In this study, we searched through various cases of cross platform and found out the search pattern and suggested correct usage method accordingly. As a result, the search structure for cross platform can be divided into persistent navigation, temporary navigation, and auxiliary navigation. Persistent navigation is available in a hierarchical structure using springboards, lists, galleries, and top menus. Temporary navigation can take advantage of drawers, toggle menus, and pie menus, while secondary navigation can provide the same experience across platforms using an accordion menu or scrolling.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.7
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• pp.2231-2245
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• 2014

Cognitive Radio (CR) has very promising potential to improve spectrum utilization by allowing unlicensed Secondary Users (SUs) to access the spectrum dynamically without disturbing licensed Primary Users (PUs). Mitigating interference is a fundamental problem in CR scenarios. This is particularly problematic for deploying CR in cellular networks, when users are located at the cell edge, as the inter-cell interference mitigation and frequency reuse are critical requirements for both PUs and SUs. Further cellular networks require higher cell edge performance, then SUs will meet more challenges than PUs. To solve the performance decrease for SUs at the cell edge, a novel Dynamic Spectrum Allocation (DSA) scheme based on Game Theory is proposed in this paper. Full frequency reuse can be realized as well as inter-cell interference mitigated according to SUs' sensing, measurement and interaction in this scheme. A joint power/channel allocation algorithm is proposed to improve both cell-edge user experience and network performance through distributed pricing calculation and exchange based on game theory. Analytical proof is presented and simulation results show that the proposed scheme achieves high efficiency of spectrum usage and improvement of cell edge SUs' performance.

• KSTLE International Journal
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• v.3 no.1
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• pp.1-6
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• 2002

The purpose of this paper is to investigate the effects of design parameters on the friction loss in piston skirt. An analytical model to describe the friction characteristics of piston skirt has been presented, which is based on the secondary motion of piston and mixed lubrication theory, It could be shown that the skirt friction closely depends on the side force acted on the piston pin. The side force is inf1uenced by cylinder pressure at low engine speed, but by inertia force at high engine speed. The usage of extensive skirt area and low weight piston is effective to reduce the friction loss at high speed. The low viscosity oil considerably decreases viscous friction as engine speed increases, but it increases boundary friction at low engine speed. From the parametric study, it is found that the skirt axial profile is the most important design parameter related to the reduction of skirt friction.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.1
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• pp.73-77
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• 2005

Plant-derived natural products have been and will continue to be valuable sources. Elicitors have been employed to modify cell metabolism in order to enhance the productivity of useful metabolites in plant cell/tissue cultures. In this study, several elicitors were used to improve the productivity of useful metabolites and to reduce culture time for archiving high concentration in P. ginseng hairy root cultures. The addition of chitosan, chitosan oligosaccharide and alginate oligosaccharide to the culture of P. ginseng hairy roots caused growth to be inhibited with the increase in elicitor concentration. The usage of the chitosan elicitor and D-glucosamine caused a slight decrease in hairy root growth, whereas total ginseng saponin accumulated slightly with the increase in elicitor concentration. When gel beads were added to the culture medium at the initial period, hairy root growth was enhanced. The maximum growth was 1.35 times higher than that of the control at $1\%$ (w/v). Total ginseng saponin content decreased due to the addition of alginate beads. This would result in consistent diffusion of lower levels of calcium ions during the culture period that promotes biomass growth.

• International Journal of Computer Science & Network Security
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• v.21 no.8
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• pp.360-368
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• 2021

This study aims at knowing both the level of information security awareness in the use of social media among female secondary school students in Makkah Al-Mukarramah, and the procedures that students follow when exposed to hacking or other security problems. The study relied on the descriptive survey approach. The results showed a high percentage of social media use among the study sample, and the most used applications by the students are snapchat and Instagram applications successively. In fact, 48% of the study sample have awareness of information security, the majority of the students memorize the password in the devices, most of them do not change them, and they have knowledge of fake gates and social engineering. However, their knowledge of electronic hacking is weak, and students do not share passwords with anyone at a rate of 67%. At the same time, they do not update passwords. Moreover, most of the procedures followed by students when exposed to theft and hacking is to change the e-mail data and the password, and the results varied apart from that, which reflects the weak awareness of the students and the weakness of procedures related to information security. The study recommends the necessity to raise awareness and education of the importance of information security and safety, especially in light of what the world faces from data electronic attacks and hackings of electronic applications.

• International Journal of Railway
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• v.5 no.1
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• pp.29-37
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• 2012

The rail sector, despite its potential for curtailing the present chaotic transport situation in Lagos, remains inefficient and underutilized. In spite of past initiatives and the current attempt by the Lagos State Government to provide a mass transit rail service in Lagos, the share of rail mode in the transport sector has not been encouraging and the railway plays an insignificant role in urban mass transit in Lagos at present. This paper sets out to assess the usage of the Lagos mass transit trains. Hence, the paper determines the passenger traffic flow along the rail route in Lagos and the number of passengers carried between 2000 and 2009 by the Lagos Mass Transit Trains (LMTT) with a view to assessing the usage of the present LMTT. This paper also discusses the historical development of Nigerian railway and describes rail transport in Lagos. Data were obtained through secondary sources coupled with review of literature. The result of this study shows that for a period of 10 years (2000-2009), Lagos mass transit trains carried a total of 9,870,101 passengers, which gives an average of 987,010 passengers annually. This suggests that the service of the Lagos mass transit train is grossly underutilized. However, LMTT contributes enormously to NRC by carrying 68.5% of the total passenger traffic of NRC between 2000 and 2009. In terms of passenger traffic flow along the route of LMTT, for a period of 1 year, Agbado station recorded the largest number of passengers (393,811), followed by Ijoko (163,652) and Iddo (120,787), while Iganmu station has the lowest number of rail commuters (16,919). This study also discloses that the major commodities hauled by Lagos district of NRC from Lagos to the northern parts of the country in 2007 are Cars, Cement, Billet and Wheat.

• Journal of Environmental Science International
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• v.22 no.5
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• pp.599-608
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• 2013

Jeju island, which is located along the moving path of typhoon, suffers from flooding and overflow by torrential rain. So abrupt runoff occurring, damages of downstream farm field and shore culturing farms are increasing. In this study, Oaedo stream, one of the mountainous streams on Jeju island, was selected as the basin of study subject and was classified into 3 sub-basins, and after the characteristics of subject basin, the soil erosion amount and the sediment delivery of the stream by land usage distribution were estimated with the use of SATEEC ArcView GIS, the sediment yield amount of 2000 and 2005 was analyzed comparatively. As a result of estimating the sediment yield amount of 2000, the three sub-basins were respectively 12,572.7, 14,080 and 157,761 tons/year. and sediment yield amounts were estimated as 35,172.9, 5,266 and 258,535 tons/year respectively in 2005. The soil erosion and sediment yield amount of 2005 using single storm rainfall were estimated high compared with 2000, but for sub-basin 2, the values rather decreased due to changes in land use, and the land coverage of 2005, since there are many classifications of land usage compared with 2000, enabling to reflect more accurate land usage condition, could deduce appropriate results. It is anticipated that such study results can be utilized as basic data to propose a direction to predict the amount of sediment yield that causes secondary flooding damage and deteriorates water quality within detention pond and grit chamber, and take action against damages in the downstream farm field and shore culturing farms.

• The Journal of the Korea Contents Association
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• v.19 no.10
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• pp.306-314
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• 2019

Based on the secondary data of the 2018 news media audience conducted by the Korean Press Foundation, this study examines how the credibility of news on web portals and from news media outlets affects the types of web portal usage. The web portal usage was categorized into the two types: paying attention to news edited by the web portals and paying attention to news media outlets. These were named "portal site centered" and "news media outlet centered," respectively. This study found that the credibility of news from the web portals showed positive relationships with both portal site centered and news media outlet centered. The credibility of news from news media outlets had statistically significant relationships with the two types of web portal usage, but it differed depending on the audiences' preferences toward news media outlets. In other words, the credibility of news from news media outlets that are usually preferred or frequently used showed a positive relationship with the portal site centered, but has a negative relationship with the news media outlet centered. On the other hand, the credibility of news from news media outlets that are not preferred or not frequently used had a negative relationship with the portal site centered, but had a positive relationship with the news media outlet centered.

• Journal of the Korean Data Analysis Society
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• v.20 no.6
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• pp.3201-3209
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• 2018

The purpose of this study was to explore the factors predicting increased usage hours of smartphone among adolescents. Secondary data was analyzed to be collected from a nationally representative sample of 2017 Korean adolescents. This study sample included 54,601 students in middle or high schools of Korea. The collected data were analyzed SPSS version 23.0 program for frequency, percentage, mean, standard deviation, t-test, ANOVA, Pearson's correlation coefficient and binary logistic regression analysis. In the results, the mean usage hour of smartphone among the adolescents was 28.42 (SD 23.30) per week. Analyses of the differences in usage hours of smartphone according to research variables were found that the groups of lower level of study (F=1361.067, p<.001) and sociality content type (F=761.549, p<.001) spent more time, as compared to the other groups. The logistic analysis showed the predictive factors for increased hour of using smartphone were smartphone usage for sociality (OR: 2.44, 95% CI: 2.26-2.64) and peer group counselor (OR: 1.49, 95% CI: 1.49). Conclusionally, the findings of this study suggests that it needs to understand cause or purpose of smartphone using of adolescent and to cope and educate on the cause.