• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.5075-5079
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• 2015

Background: Adverse effects of treatment prolongation beyond 8 weeks with radiotherapy for cervical cancer have been established. Clinical data also show that cisplatin increases the biologically effective dose of radiotherapy. However, there are no data on the effect of overall treatment time in patients with locally advanced cervical cancer treated with concomitant chemo-radiotherapy (CCRT) in an Indian population. The present study concerned the feasibility of concurrent chemotherapy and interspacing brachytherapy during the course of external radiotherapy to reduce the overall treatment time and compare the normal tissue toxicity and loco-regional control with a conventional schedule. Materials and Methods: Between January 2009 and March 2012 fifty patients registered in the Gynaecologic Oncology Clinic of Institute Rotary Cancer Hospital with locally advanced cervical cancer (FIGO stage IIB-IIIB) were enrolled. The patients were randomly allocated to treatment arms based on a computer generated random number. Arm I (n=25) treatment consisted of irradiation of the whole pelvis to a dose of 50 Gy in 27 fractions, and weekly cisplatin $40mg/m^2$. High dose rate intra-cavitary brachytherapy (HDR-ICBT) was performed after one week of completion of external beam radiotherapy (EBRT). The prescribed dose for each session was 7Gy to point A for three insertions at one week intervals. Arm II (n=25) treatment consisted of irradiation of the whole pelvis to a dose of 50 Gy in 27 fractions. Mention HDR-ICBT ICRT was performed after 40Gy and 7Gy was delivered to point A for three insertions (days 23, 30, 37) at one week intervals. Cisplatin $20mg/m^2/day$ was administered from D1-5 and D24-28. Overall treatment time was taken from first day of EBRT to last day of HDR brachytherapy. The overall loco-regional response rate (ORR) was determined at 3 and 6 months. Results: A total of 46 patients completed the planned treatment. The overall treatment times in arm I and arm II were $65{\pm}12$ and $48{\pm}4$ days, respectively (p=0.001). At three and six months of follow-up the ORR for arm I was 96% while that for arm II was 88%. No statistically significant difference was apparent between the two arms. The overall rate of grade ${\geq}3$ toxicity was numerically higher in arm I (n=7) than in arm II (n=4) though statistical significance was not reached. None of the predefined prognostic factors like age, performance status, baseline haemoglobin level, tumour size, lymph node involvement, stage or histopathological subtype showed any impact on outcome. Conclusions: In the setting of concurrent chemoradiotherapy a shorter treatment schedule of 48 days may be feasible by interspacing brachytherapy during external irradiation. The response rates and toxicities were comparable.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.12
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• pp.1245-1254
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• 2008

Proposing a method for the estimation of the social cost for global warming impact (external cost) is the aim of this paper. Both the endpoint approach and conjoint analysis were applied to estimating the social cost for global warming. The endpoint approach was used to assess the damage on the safeguard subjects by global warming due to the emission of greenhouse gases into the atmosphere. The conjoint analysis was used to estimate the economic values for safeguard subjects which measure the social preferences and willingness to pay (WTP) on safeguard subjects. The economic values of human health and social asset were estimated at 62,261,700 Won / DALY (yr) and 10,000 Won / 10,000 Won, respectively. Moreover, cost factors of GHGs were calculated by multiplying the damage factor which is quantified the unit damage on safeguard subject and the economic value. In the case of CO$_2$, the cost factor was calculated at 13.52 Won / kg (13,520 Won / ton). External cost of products or services can be calculated by multiplying the GHG inventory result of products or services by the cost factor of each GHG. inventory.

• Journal of Radiation Protection and Research
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• v.33 no.2
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• pp.67-76
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• 2008

As the first comprehensive attempt at a national implementation, this study aims at assessing the external costs of major electricity generation technologies in Korea, particularly an evaluation of the impacts on human health resulting from exposures to atmospheric radiological emissions from nuclear power plants, and a monetary quantification of their damages. The methodology used for the assessment of the externalities of the selected fuel cycles has been developed by the International Atomic Energy Agency (IAEA), namely the SimPacts Model Package. The model is internationally recognized as a tool which can be applied to a wide range of fuels, different technologies and locations, for an externalities study. In this study, the relevant emissions are quantified first and then their impacts on human health are evaluated and compared. The study focused on all the nuclear power plants for the last 6 years ($2001{\sim}2006$) in Korea. With respect to nuclear power, the impact analysis only focuses on a power generation, however the front- and back-end nuclear fuel cycles are not included, namely uranium mining, conversion, enrichment, reprocessing, conditioning, etc., because these facilities are not present in Korea. The analysis results show that nuclear power in general, generates low external costs. The highest damage costs from the nuclear power plants among the 4 sites in Korea were estimated to be 3.9 mills/MWh, which is about 1/20th of the result for a similar case study conducted in the U.K., implemented through the ExternE project. This difference is largely due to the number of radionuclides included in the study and the amount of released radioactive emissions based on up-to-date information in Korea. In this study, the sensitivities of the major factors for nuclear power plants were also calculated. The analysis indicates that there was around a ${\pm}3%$ damage costs variation to a ${\pm}15%$ change of the reference population density and a ${\pm}1%$ damage cost variation to a $1{\sim}30$ meters change of the effective release height, respectively. These sensitive calculations show that there is only a minor difference when the reference costs are compared.

• Korean small business review
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• v.41 no.3
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• pp.23-47
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• 2019

This study investigates the effects of three types of person-environment fit, i.e. POF, PJF(ability) and PJF(needs), on effectiveness variables and the mediating effect of work motivation in SMEs. The data were collected from 211 employees who work for SMEs. Results of structural equation modeling(SEM) analyses demonstrated that PJF(ability) was significantly associated with task performance and turnover intention, while POF and PJF(needs) were significantly associated with turnover intention only. PJF(needs) and PJF(ability) have the positive impact on intrinsic motivation, PJF(ability) also has the positive impact on external and identified motivation. We also analysed mediating effects using Process macro. Results demonstrated that intrinsic motivation mediated the relationship between POF, PJF(needs), PJF(ability) and task performance. The relationship between PJF(ability) and task performance was mediated by external motivation. Based on the results, theoretical and practical implications are derived. Also suggested are methodological limitations and future research directions.

• Journal of Industrial Convergence
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• v.21 no.8
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• pp.1-12
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• 2023

The purpose of the study is to analyze the impact of blended learning's external classroom formats and internal teaching strategies, which has been implemented in university classes due to COVID-19, on students' academic achievement and learners' perceptions, as well as to provide insights into the desirable direction of online education. The study was conducted during the 1st semester of 2022 at G University, targeting students taking Calculus I. The experimental group consisted of 117 students, while the control group consisted of 707 students. Blended learning, involving a combination of face-to-face classes, online classes, and mixed teaching methods, was implemented, and academic achievement and learner perceptions were assessed. The research findings indicate that compared to solely online classes, adopting a blended learning approach with online classes before the midterm and face-to-face classes afterwards resulted in a decline in academic achievement. The unprepared and simplistic external format of blended learning was found to be ineffective, however, a blended learning model consisting solely of online classes, incorporating a mix of asynchronous and synchronous instruction, demonstrated positive learner perceptions. Additionally, utilizing technology in the teaching strategies yielded positive outcome.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.709-713
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• 2017

In urgent situations such as crashes, the integrity of an aircraft's fuel tank is directly related to the survivability of the crew. Thus, an external auxiliary fuel tank should be robust against bird strikes. In this study, a numerical analysis was carried out using impact analysis software to analyze the influence of bird strike on a composite container for an external auxiliary fuel tank. The structure was modeled as a shell element, and the fluid and bird were modeled by the particle method. The behavior of the internal fluid was also examined. The maximum stress, deformation, and strain of the composite container were also calculated.

• Journal of Periodontal and Implant Science
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• v.46 no.5
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• pp.329-336
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• 2016

Purpose: The aim of this study was to clinically assess the impact of a prefabricated implant-retained stent clipped over healing abutments on the preservation of keratinized mucosa around implants after implant surgery, and to compare it with horizontal external mattress sutures. Methods: A total of 50 patients were enrolled in this study. In the test group, a prefabricated implant-retained stent was clipped on the healing abutment after implant surgery to replace the keratinized tissue bucco-apically. In the control group, horizontal external mattress sutures were applied instead of using a stent. After the surgical procedure, the width of the buccal keratinized mucosa was measured at the mesial, middle, and distal aspects of the healing abutment. The change in the width of the buccal keratinized mucosa was assessed at 1 and 3 months. Results: Healing was uneventful in both groups. The difference of width between baseline and 1 month was $-0.26{\pm}0.85mm$ in the test group, without any statistical significance (P=0.137). Meanwhile, the corresponding difference in the control group was $-0.74{\pm}0.73mm$ and it showed statistical significance (P<0.001). The difference of width between baseline and 3 months was $-0.57{\pm}0.97mm$ in the test group and $-0.86{\pm}0.71mm$ in the control group. These reductions were statistically significant (P<0.05); however, there was no difference between the 2 groups. Conclusions: Using a prefabricated implant-retained stent was shown to be effective in the preservation of the keratinized mucosa around implants and it was simple and straightforward in comparison to the horizontal external mattress suture technique.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.11
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• pp.5642-5670
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• 2017

Antivirus is an important issue to the security of virtual machine (VM). According to where the antivirus system resides, the existing approaches can be categorized into three classes: internal approach, external approach and hybrid approach. However, for the internal approach, it is susceptible to attacks and may cause antivirus storm and rollback vulnerability problems. On the other hand, for the external approach, the antivirus systems built upon virtual machine introspection (VMI) technology cannot find and prohibit viruses promptly. Although the hybrid approach performs virus scanning out of the virtual machine, it is still vulnerable to attacks since it completely depends on the agent and hooks to deliver events in the guest operating system. To solve the aforementioned problems, based on in-memory signature scanning, we propose an agentless runtime antivirus system VirtAV, which scans each piece of binary codes to execute in guest VMs on the VMM side to detect and prevent viruses. As an external approach, VirtAV does not rely on any hooks or agents in the guest OS, and exposes no attack surface to the outside world, so it guarantees the security of itself to the greatest extent. In addition, it solves the antivirus storm problem and the rollback vulnerability problem in virtualization environment. We implemented a prototype based on Qemu/KVM hypervisor and ClamAV antivirus engine. Experimental results demonstrate that VirtAV is able to detect both user-level and kernel-level virus programs inside Windows and Linux guest, no matter whether they are packed or not. From the performance aspect, the overhead of VirtAV on guest performance is acceptable. Especially, VirtAV has little impact on the performance of common desktop applications, such as video playing, web browsing and Microsoft Office series.

• The Journal of the Korea Contents Association
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• v.15 no.11
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• pp.534-549
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• 2015

This study was conducted in 2014 with Osong International Bio Industry Expo volunteers as the subjects of the study. The study has analyzed whether their participation motivation, participation satisfaction, and educational training have moderating effects between their motivation and satisfaction. The purpose is to offer implications for successfully holding large events in the future. The findings are as follows. First, the internal reward, a sub-factor of participation motivation, had statistically significant effects on the six elements of volunteering satisfaction. Second, the external reward, a sub-factor of volunteering motivation, had statistically significant effects on the four elements of volunteering satisfaction: self-satisfaction about their abilities; satisfaction in pursuing changes; satisfaction in the event and satisfying interests. However, their satisfaction in self-growth and in interactions were excluded from the volunteering satisfaction elements that were critically affected by the external reward. Third, the training had moderating effects between their internal reward and satisfaction in the event. Forth, the training had moderating effects between their external reward and satisfaction in the event.

• Journal of the Society of Naval Architects of Korea
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• v.57 no.4
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• pp.213-220
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• 2020

In the present paper, implosion responses of two adjacent cylindrical tubes under external hydrostatic pressure were experimentally investigated. The cylinder models were fabricated of aluminium alloy 6061-T6 commercial tubes. In the experiment, a pair of two-cylinders were placed inside of a support frame in a medium-size pressure chamber, whose design pressure was 6.0MPa. The distance between the two-cylinders was 30 millimeter measured from outer shell at the mid-length. The implosion tests were performed with water and compressed nitrogen gas as the pressurizing media. The ambient static pressure of the chamber and local dynamic pressure near the two-imploded models were measured simultaneously. It was found that the energy released during an implosion from the first, weaker cylinder triggered the instability of the second, stronger cylinders. In other words, the resulting shock wave of the first implosive impact from the weaker cylinder could cause the premature failure of the neighboring stronger cylinders. The non-contact implosion phenomena from the two-cylindrical tube were clearly observed.