• Journal of Radiation Protection and Research
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• v.41 no.2
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• pp.161-165
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• 2016

Background: Radiation accidents having occurred in recent containing the accident in Fukushima nuclear power plants of Japan were resulted to the increase in some public concern, anxiety and confusion for radiation or nuclear safety. The public anxiety for radiation is not being decreased though the announcements done in radiation research institutes in Korea. Therefore, this study aims at providing an effective system for radiation publicity to the public members by the clipping analysis for the radiation articles reported in the media. And, the relation between those radiation issues and the radiation perception to the public members is analyzed. Materials and Methods: The radiation articles reported by them in 2013 and 2014 have been collected, and they are then classified with the article characteristic, field and tendency. Classified articles have been reviewed by dividing as two year. The 210 articles have been compared for their tendencies, characteristics and fields by year reported, and their characteristic comparison by reported year are then reviewed. Results and Discussion: Though the frequency that the radiological accidents have occurred in worldwide is far low compared to the accidental frequencies occurred in the general industrial fields, the radiation perception is being still deteriorated because of its special problem, which is defined as exposure, contamination or radioactivity, about radiation. The basic principles for radiation communication were suggested for preventing some unnecessary misunderstanding due to the variation of understanding for radiation issues. Conclusion: It is necessary to perform a variety of strategies for the publicity in improving the radiation perception, to build a relationship with the press or the media and then to consistently interact with them. Radiation communication must be performed by radiation experts or complete charge department, and must be consistently performed and be taken predictable patterns.

• Journal of Radiation Industry
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• v.5 no.4
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• pp.377-382
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• 2011

Poly(vinyl alcohol) (PVA) is an interesting material with good biocompatibility, high elasticity and hydrophilic chacrateristics. In this study, crosslinked hydrogels based on PVA, and poly(acrylic acid) (PAAc) were prepared by gamma-ray irradiation. PVA and PAAc powders were dissolved in deionized water, and then irradiated by a gamma-ray with a radiation dose of 50 kGy to make hydrogels. The hydrogels were then annealed in an oven at $120^{\circ}C$ for 10 min, 30 min and 50 min under nitrogen atmosphere. The properties of a hydrogel such as gel fraction, swelling behavior, thermogravimetric analysis (TGA) and adhesive strength as a function of PAAc content and annealing time were investigated. The gel fraction decreases with decreasing PAAc content and increasing annealing time. The thermal behaviors have shown different patterns according to the annealing time. The adhesive strength increases with increasing PAAc content.

• Radiation Oncology Journal
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• v.33 no.1
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• pp.29-35
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• 2015

Purpose: To analyze the prognostic factors for survivals and to evaluate the impact of postoperative whole pelvic radiotherapy (WPRT) on pelvic failure in patients with uterine sarcoma treated with radical surgery. Materials and Methods: We retrospectively analyzed 75 patients with uterine sarcoma who underwent radical surgery with (n = 22) or without (n = 53) radiotherapy between 1990 and 2010. There were 23 and 52 patients with carcinosarcoma and non-carcinosarcoma (leiomyosarcoma, 22; endometrial stromal sarcoma, 25; others, 5), respectively. The median follow-up period was 64 months (range, 17 to 269 months). Results: The 5-year overall survival (OS) and pelvic failure-free survival (PFFS) of total patients was 64.2% and 83.4%, respectively. Multivariate analysis revealed that mitotic count (p = 0.006) was a significant predictor of OS. However, factors were not found to be associated with PFFS. On analyzing each of the histologic subtypes separately, postoperative WPRT significantly reduced pelvic failure in patients with carcinosarcoma (10.0% vs. 53.7%; p = 0.046), but not in patients with non-carcinosarcoma (12.5% vs. 9.9%; p = 0.866). Among the patients with carcinosarcoma, 4 patients (17%) had recurrence within the pelvis and 3 patients (13%) had recurrence in other sites as an initial failure, whereas among the patients with non-carcinosarcoma, 3 patients (6%) experienced pelvic failure and 13 patients (25%) experienced distant failure. Conclusion: The most significant predictor of OS was mitotic count. Based on the improved PFFS after postoperative WPRT only in patients with carcinosarcoma and the difference in patterns of failure between histologic subtypes, optimal adjuvant treatment options should be offered to patients based on the risk of recurrence patterns.

• Radiation Oncology Journal
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• v.18 no.3
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• pp.167-176
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• 2000

The objective of recent radiation therapy is to improve the quality of treatment and the after treatment quality of life. In Korea, sharing the same objective, significant advancement was made due to the gradual increase of patient number and rapid increase of treatment facilities. The advancement includes generalization of three-dimensional conformal radiotherapy (3D-CRT), application of linac-based stereotactic radiosurgery (SRS), and furthermore, the introduction of intensity modulated radiation therapy (IMRT). Authors in this paper prospectively review the followings: the advancement of radiation oncology in Korea, the recent status of four-dimensional radiation therapy, IMRT, the concept of the treatment with biological conformity, the trend of combined chemoradiotherapy, the importance of internet and radiation oncology information management system as influenced by the revolution of information technology, and finally the global trend of telemedicine in radiation oncology. Additionally, we suggest the methods to improve radiotherapy treatment, which include improvement of quality assurance (QA) measures by developing Koreanized QA protocol and system, regional study about clinical protocol development for phase three clinical trial, suggestion of unified treatment protocol and guideline by academic or research societies, domestic generation of treatment equipment's or system, establishment of nationwide data base of radiation-oncology-related information, and finally patterns-of-care study about major cancers.

• Radiation Oncology Journal
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• v.11 no.2
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• pp.285-294
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• 1993

A total of forty patients with resected N2 stage non-small cell lung cancer treated with postoperative adjuvant radiation therapy between Jan. 1975 and Dec. 1990 at the Department of Radiation Oncology, Yonsei University College of Medicine, Yonsei Cancer Center were retrospectively analysed to evaluate whether postoperative radiation therapy improves survival. Patterns of failure and prognostic factors affecting survival were also analysed. The 5 year overall and disease free survival rate were $26.3\%,\;27.3\%$ and median survival 23.5 months. The 5 year survival rates by T-stage were $T1\;66.7\%,\;T2\;25.6\%\;and\;T3\;12.5\%.$ Loco-regional failure rate was $14.3\%$ and distant metastasis rate was $42.9\%$ and both $2.9\%.$ Statistically significant factor affecting distant failure rate was number of postitive lymph nodes(>=4). This retrospective study suggests that postoperative radiation therapy in resected N2 stage non-small cell lung cancer can reduce loco-regional recurrence and may improve survival rate as compared with other studies which were treated by surgery alone. Further study of systemic control is also needed due to high rate of distant metastasis.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.10
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• pp.63-71
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• 2009

The patch antennas with an array of pins with excellent radiation characteristics are investigated for several substrate thicknesses. The patch length of a pin array patch antenna for the maximum suppression of radiation in the horizontal plane decreases as the substrate thickness increases. The radiation in the horizontal plane of a pin array patch antenna is very small compared to that of a conventional patch antenna. The increase of forward radiation and the decrease of backward radiation of a pin array patch are obtained compared to those of a conventional patch antenna. The half-power beamwidth of E-plane radiation pattern of a pin array patch antenna is narrow compared to that of a conventional patch antenna so that the directivity is improved.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.2
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• pp.24-29
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• 2015

In this paper, a microstrip antenna with isoflux radiation patterns is presented for Low Earth Orbit(LEO) medium-sized satellites. Because of making isoflux patterns, the ground of proposed antenna under the patch was transform into a trapezoid for adjusting fringing field between the patch and ground. Next, the cavity walls were located at end of the ground for reducing back radiation. The proposed antenna was designed to receive S-band uplink(2.025 ~ 2.110 GHz) and the dimensions of the designed antenna with the ground are $160mm{\times}160mm{\times}40mm$ ($1.1{\lambda}{\times}1.1{\lambda}{\times}0.3{\lambda}$, ${\lambda}$ is the free-space wavelength at 2.068 GHz). Measured -10 dB bandwidth was 90 MHz(4.4 %) and it covers the required system bandwidth. Also, measured 3 dB axial ratio was 18 MHz(0.9 %). On the other hand, measured radiation patterns were isoflux patterns and its measured gain was 5.31 dBi at E-plane $46^{\circ}$ in the y-axis pol.

• Korean Journal of Optics and Photonics
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• v.18 no.4
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• pp.264-269
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• 2007

Today's research has been focused on changing the light source from filament to LED for luminarie illumination to overcome the shortcoming of a filament. The purpose of this research is to make an appropriate high power LED package structure for luminarie. We simulated radiation patterns of the various structures by the ray tracing simulator (Light Tools), and also analyzed the radiation patterns using an LED test system (OL770). As we increased an inner reflector angle, the radiation pattern split into two peaks and the angle between two peaks became larger. In addition, when we increased an outer reflector angle, the angle between side peaks gradually decreased, while it increased again when the angle reach $50^{\circ}$. These results could be understood from the ray tracing of the light reflected from two reflectors. We made the high power LED package for luminarie on the condition of the optimized structure which was made by ray tracing simulation results, and we measured the radiation patterns by using an LED test system, and these results were well matched to the simulation results.

• Journal of Chest Surgery
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• v.26 no.9
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• pp.686-695
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• 1993

A total of eighty one patients with resected stage II and IIIA non-small cell lung cancer treated with postoperative adjuvant radiation therapy between Jan. 1971 and Dec. 1990 were retrospectively analysed to evaluate whether postoperative radiation therapy improves survival. Patterns of failure and prognostic factors were also analysed. The 5 year overall and disease free survival rate were 40.5%, 43.4% and median survival 30 months. The 5 year actuarial survival rates by stage II and IIIA were 53.9% and 36.2%. Loco-regional failure rate was 14.7% and distant metastasis rate was 33.3% and both 4%. Statistically significant prognostic factor affecting survival was presence of mediastinal lymph node metastasis[N2]. This retrospective study suggests that postoperative radiation therapy in resected stage II and IIIA non-small cell lung cancer can reduce loco-regional recurrence and may improve survival rate as compared with other studies which were treated by surgery alone.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.1
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• pp.33-37
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• 2009

In this paper, a printed small Ultra-Wideband (UWB) antenna with directive radiation characteristics based on combination of electric-magnetic radiators is presented. The combinations of the electric and magnetic type antennas result in the directive radiation patterns for all observed UWB frequency band. Simple combination of dipole antenna and loop antenna is also presented to show that proper configuration of electric radiator and magnetic radiator can produces directive radiation characteristics. The target frequency is from 3.1 GHz to 10.6 GHz with size of $15\;mm{\times}31\;mm$. A proto-type of the combined antenna is simulated, fabricated and measured. Simulation and experimental results of input impedance and gain characteristics of the proposed antenna are presented. There are good agreements between the simulated and measured VSWR curves. Also, the results show the directive radiation characteristics with small antenna form factor over the target frequency range.