• Journal of radiological science and technology
• /
• v.36 no.3
• /
• pp.237-244
• /
• 2013

The purpose of this study is to compare method in the treatment of breast cancer using dose index. And, it is to find the optimized treatment technique to the patient. The phantom filled with tissue-equivalent material were used simulation and treatment as techniques of 3D-CRT, IMRT, VMAT was planned using Eclipse v10. By using HI(homogeneity index), CI(Conformity index), OED(Organ equivalent dose), EAR(Excess Absolute Risk), were assessed for each treatment plans. HI and CI of 3D-CRT, IMRT, VMAT were calculated 16.89, 11.21, 9.55 and 0.59, 0.61, 0.83. The organ average doses of Lt lung, Rt lung, liver, heart, esophagus, cord, Lt breast, trachea and stomach were 0.01 ~ 2.02 Gy, 0.36 ~ 5.01 Gy, 0.25 ~ 2.49 Gy, 0.14 ~ 6.92 Gy, 0.03 ~ 2.02 Gy, 0.01 ~ 1.06 Gy, 0.25 ~ 6.08 Gy, 0.08 ~ 0.59 Gy, 0.01 ~ 1.34 Gy, respectively. The OED, EAR of the IMRT and VMAT show higher than 3D-CRT. As the result of this study, we could confirm being higher dose index(HI, CI) in IMRT and VMAT than 3D-CRT, but doses of around normal organs was higher IMRT, VMAT than 3D-CRT.

• Korean journal of communication and information
• /
• v.43
• /
• pp.152-172
• /
• 2008

The convergence of media poses serious challenges to technologies, industries and policy makers. At the core of the challenges lies a socially and culturally problematic condition of 'media unlimited.' Under the circumstances, the idea of public interest of the media seems to lose its intervening leverage as it flounders in countering 'the media torrent' rushing from the exponential growth of ICTs that overwhelms contemporary life and society. It is an urgent task for the critical community to blaze fresh new thoughts about the idea to intervene in the current age of media excess. Beyond the conventional content-conduit-centered perspective on the media, this study suggests a media-environment concept based on media ecology as an engaging leverage to replenish the public interest idea. The environmental approach to the media means literally to conceptualize the media as environment--a cultural eco-system. This study explores the potential of ecological approach in enriching the conceptual terrain of policy discussions and policy-making processes concerning the public interest idea that hopefully enlightens all the media actors concerned.

• Journal of the Korea Convergence Society
• /
• v.7 no.6
• /
• pp.205-212
• /
• 2016

This study attempts to empirically investigate if value strategy and momentum strategy could be improved by using past financial data such as ROE and PER in the Korean stock market. The study observes that both strategies which are refined by the portfolios consisting of companies with higher ROE/PER ratio show higher positive excessive returns than the traditional value strategy and momentum strategy. The study discusses that the excessive returns could be due to investors' behavioral biases such as conservatism, anchoring, confirmation, and herding by using convergent approach based on psychology theory. The results are not consistent with the efficient market hypothesis insisting investors' rational behavior.

• Journal of the Korea society of information convergence
• /
• v.7 no.2
• /
• pp.41-48
• /
• 2014

Capitalism of altitude in modern society has brought a brilliant development of human civilization. But there is a side effect of capitalism. It is just such as alienation of labor, polarization. The need to consider the worker's equal rights to share profits of private companies in the first Korean Constitution of 1948 is to mitigate the adverse effects of this capitalism. It is considered that the present government aims at "economic democracy" slogan and also be matched. The worker's equal rights to share profits of private companies means the distribution rights of workers to receive excess profits of the company. The review of these worker's equal rights to share profits of private companies is thought very meaningful.

• Journal of the Institute of Convergence Signal Processing
• /
• v.7 no.4
• /
• pp.195-200
• /
• 2006

The conventional discrete circuit for ABS/TCS system was examined and the problems of the system were analyzed by computer simulation. In order to improve the performance of ABS/TCS system, interface IC which has error compensation, comparator and under voltage lock-out circuit was designed and their electrical characteristics were investigated. The voltage regulator was included to compensate the temperature variation in the temperature range from $-20^{\circ}C$ to $120^{\circ}C$ for automobile environment. ABS and brake signal were separated using the duty factor of same frequency or different frequencies. UVLO(Under Voltage Lock-Out) circuit and constant current circuit were applied for the elimination of noise, and protection circuit was applied to cut the excess current off. Layout for IC fabrication was designed to enhance the electrical performance of ABS/TCS system. Layout was consisted of 11 masks, arrayed effectively 8 pads to reduce the current loss. We can see that the result of layout simulation was better than the result of bread board.

• Journal of the Korea Convergence Society
• /
• v.10 no.11
• /
• pp.345-352
• /
• 2019

This paper examines the opportunistic behavior of corporate insiders and analyzes the relationship between equity change and the possibility of delisting. The findings are summarized as follows. First, the larger the stake reduction of insider, the greater the negative excess return after announcement. In the delisting firm group, there is a significant decrease in equity and statistically significant results in the difference test between the comparative groups. The logistic regression analysis showed that the regression coefficient of equity change was negatively statistically significant, indicating a significant correlation between insider share change and the possibility of delisting. These findings are expected not only to provide useful information for investors, but also to be evidence of capital market information asymmetry.

• Journal of the Korea Convergence Society
• /
• v.10 no.9
• /
• pp.199-207
• /
• 2019

This study aims to analyze the profitability of Robo-Advisors portfolio combined with the analysts' forecasts on the Korean stock prices. Sample stocks are 8 blue-chips and sample period is from 2003 to 2019. Robo-Advisor portfolio was suggested using the Black-Litterman model combined with the analysts' forecasts and its profitability was analyzed. Empirical result showed the suggested Robo-Advisor algorithm produced 1% annual excess return more than that of the benchmark. The study documented that the analysts' forecasts had an economic value when applied in the Robo-Advisor portfolio despite the prevalent blames from investors. The profitability on small or medium-sized stocks will need to be analyzed in the Robo-Advisor context because their information is relatively less known to investors and as such is expected to be strongly influenced by the analysts' forecasts.

• Journal of Environmental Health Sciences
• /
• v.48 no.1
• /
• pp.44-51
• /
• 2022

Background: Air pollution is increasing together with industrialization and urbanization. In order to reduce air pollution, public transportation is recommended rather than private cars, and the number of passengers using public transportation is increasing accordingly. This study observes the concentration of indoor pollutants in city buses over time. Through this means, we intend to suggest a plan to manage the indoor air quality in city buses. Objectives: The concentration of indoor pollution in public transportation was investigated from April 2021 to January 2022. Based on this, we evaluated the exposure to indoor pollutants. Methods: Six city bus lines in an industrial city were selected for the research, and indoor pollution was measured through IoT (Internet of Things)-based sensor-type measuring devices. The concentration of pollutants was measured every minute, and statistical data were constructed based on the measurement results. Results: In all the city buses studied, the average concentration of pollutants were below the guidelines. However, some measurement results showed cases of exceeding the guidelines. As a result of the analysis by time zone, there were more cases in which pollutants exceeded the standard value during rush hour compared to at other times. A risk assessment for PM₁₀ was performed by evaluating the excess mortality risk from exposure and the risk from inhalation exposure. Conclusions: All measured indoor pollutants in the city buses did not exceed the guidelines. Also, the risk assessment results were found to be within the level of safety. However, if a city bus is used for a long time, there is a possibility that there may be an impact on the human body due to inhalation exposure, so additional management is required.

• Journal of the Korean Society of Industry Convergence
• /
• v.26 no.5
• /
• pp.915-923
• /
• 2023

As environmental regulations on carbon emissions are strengthened worldwide, the existing internal combustion engine-centered automobile industry is being reformed. In particular, large buses and large cargo trucks are pointed out as one of the main causes of environmental destruction due to excessive carbon emissions. The E-Highway power collection system, which has recently been proposed as a solution, uses the vehicle's battery as a backup power source or regenerative braking, depending on whether the pan head of the pentograph installed in the vehicle is in contact with the overhead line. It is used to store the excess energy generated. However, wear through contact due to continuous contact reduces the current collection effect and causes failure. In this paper, by using the current difference, the horizontal position information of the panhead in contact with the overhead line is acquired, thereby reducing the abrasion of the conductor and the panhead Make it possible to follow the overhead line. The position estimation method proposed in this paper simply configures a device that can detect the position of the overhead line of the pantograph by the difference in resistance. It is economical and has the advantage of reducing the volume. The characteristics of the pantograph estimating the location of overhead lines were analyzed using the difference between the two currents of the current collector, the feasibility of the positioning estimation system was verified through simulations and experiments.

• Carbon letters
• /
• v.22
• /
• pp.36-41
• /
• 2017

Biodegradable epoxy (B-epoxy) was prepared from diglycidyl ether of bisphenol A and epoxidized linseed oil. The mechanical properties of B-epoxy composites reinforced with multi-walled carbon nanotubes (MWCNTs/B-epoxy) were examined by employing dynamic mechanical analysis, critical stress intensity factor ($K_{IC}$) tests, and impact strength tests. The electromagnetic interference shielding effectiveness (EMI-SE) of the composites was evaluated using reflection and absorption methods. Mechanical properties of MWCNTs/B-epoxy were enhanced with an increase in the MWCNT content, whereas they deteriorated when the MWCNT content was >5 parts per hundred resin (phr). This can likely be attributed to the entanglement of MWCNTs with each other in the B-epoxy due to the presence of an excess amount of MWCNTs. The highest EMI-SE obtained was ~16 dB for the MWCNTs/B-epoxy composites with a MWCNT content of 13 phr at 1.4 GHz. The composites (13 phr) exhibited the minimum EMI-SE (90%) when used as shielding materials at 1.4 GHz. The EMI-SE of the MWCNTs/B-epoxy also increased with an increase in the MWCNT content, which is a key factor affecting the EMI-SE.