• Journal of radiological science and technology
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• v.41 no.6
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• pp.567-572
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• 2018

Radiation therapy is one of the beneficial choices in the treatment of cancer. This is a comparison of TPS(Treatment Planning System) and GEANT4-DICOM, which should be preceded by the best radiation therapy. A treatment plan for prostate cancer was established with Eclipse and the point doses 366.1 cGy, 189.1 cGy, 213.4 cGy, 127 cGy, 105.7 cGy of any five prostate, bladder, rectum, right femoral head and left femoral head were identified. GEANT4-DICOM simulation showed that the results of Eclipse and ${\pm}2%$ dose error were confirmed. The monthly X-ray output agreement management value recommended by TG-142 is ${\pm}2%$, which means that the experimental results can be meaningful. In conclusion, GEANT4-DICOM is an infinite way to obtain more extended dose information once the time constraints are overcome in the simulation.

• Journal of Korean Society of Rural Planning
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• v.24 no.4
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• pp.47-55
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• 2018

Currently in the drought evaluation, which is a supplier-oriented standard that applies storage rates of reservoirs, evaluation for users that use agricultural water is not done. Therefore, this study established drought evaluation items for drought evaluation based on farmers' judgement, conducted a survey on farmers and experts, compared and analyzed weighted value between two groups, and then classified the evaluation standards per each evaluation item. The agricultural drought evaluation items are 5 major items of water supply lapse rate, agricultural weather, agricultural irrigation facility, crop and soil, and 12 subsections for regional characteristics and opinions of consumers that use water to be reflected. The result of analyzing weighted value of farmers and experts' major items shows that farmers is agricultural irrigation facility(0.219), water supply lapse rate(0.211), agricultural weather(0.204), crop(0.183) and soil(0.183). Experts is agricultural weather(0.297), agricultural irrigation facility(0.202), water supply lapse rate(0.189), crop(0.162) and soil(0.150), which displays difference between the two groups. The agricultural drought criteria standards are established based on precedent studies and cases, and grades of evaluation items are 1st grade(extreme stage), 2nd grade(warning stage), 3rd grade(alert stage) and 4th grade(attention stage). The above analysis per each consumer-oriented agricultural drought evaluation item and the analysis on the standards of evaluation grades are expected to be used as a basic resource for establishing agriculture drought policy and selecting drought area in the future.

• Journal of Aerospace System Engineering
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• v.13 no.1
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• pp.29-37
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• 2019

The objective of this study was to investigate the influence of the blade shape on the impeller performance, for design optimizing of the high airflow impeller. First, the quantity, angle, and length of blades, which are considered to have a large influence on the impeller performance, were selected as design variables. Then, 27 cases of impeller shapes were selected according to the design of experiment (DOE). To predict the conduct of the blower based on the selected impeller shape, flow analysis was performed using the immersed solid method of ANSYS CFX. In the CFD results, the highest airflow was expected in the impeller having a combination of 50 EA, $6^{\circ}$ and 5 mm. Finally, a blower with the original impeller shape and the optimized impeller shape was fabricated using a 3D printer, and the analysis tendency and experimental tendency were verified through experiments.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.30 no.2
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• pp.211-243
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• 2019

According to article 11 of the Public Records Management Act of Korea, metropolitan city, special self-governing city, province or special self-governing province should establish archival institutions for permanent preservation and management of records. As a result, the establishment and operation of archival institutions in Korea has been increase, but since it is still in the stage of introduction, the mission and role of these archives have not been specified by archives act. Therefore, we need to establish a proper legal basis to support it. To do this, it explores the archives act in China, Russia and Germany in terms of basic operational policy, collection and transfer of records, management of records, and service of records. As a result, the study presents some implications for the archives act for the management of archives in Korea.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.15 no.1
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• pp.1-6
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• 2019

There are increasing number of patients having dental treatment under outpatient general anesthesia. There were researches that studied patients treated under outpatient general anesthesia in Chonbuk National University Dental hospital between 2005~2013. However, there has been an absence of research since 2013. Therefore, the aim of this research is to study cases regarding outpatient general anesthesia visiting Chonbuk National University hospital between 2014~2017 and analyze the trends of these patients. The medical records of 409 cases from January, 2014 to December, 2017 were reviewed. From the patients' charts, data on sex, residence, visiting dates, disability status, and types and number of treatments was collected and investigated. The number of cases has increased from 86 in 2014 to 140 in 2017. Among 409 cases, 275 cases(67.2%) had disabilities, with mental disabilities consisting most of the disabilities. 192 cases were aged under 20 years old mostly with no disabilities, 142 cases were 20~39 years old mostly with mental disabilities, and 75 cases were 40 years old or more mostly with physical disabilities. The conservative treatment was performed most frequently in both disabled and non-disabled patient groups. There was an increasing trend in the number of patients treated under outpatient general anesthesia, and more than half were disabled patients. In order to meet this demand, Chonbuk National University Dental Hospital increased the number of general anesthesia pracrice. To follow this trends, the implementation of safe outpatient general anesthesia system and cooperation among teams is needed to improve the quality of treatments.

• Korean Journal of Metals and Materials
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• v.49 no.2
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• pp.161-166
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• 2011

The aim of this study was to determine the effect of high-energy mechanical milling (HEMM) time and sintering temperature on microstructure and mechanical properties of the TiAl composite fabricated by pulse current activated sintering. TiAl intermetallic powders were milled by HEMM for 1h, 4h, and 8h respectively. Thermal analysis was used to observe the phase transformation of the milled TiAl powders. The sintering time decreased with increase of milling time. The hardness and fracture toughness of the sintered specimens also was improved with increasing milling time. The grain size of the sintered specimens which was milled for 4h was in the range of 50~100 nm.

• Korean Journal of Metals and Materials
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• v.48 no.4
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• pp.369-375
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• 2010

Ti-6Al-4V ELI alloy, which is commonly used as a biomaterial, is associated with a high elastic modulus and poor biocompatibility. This alloy presents a variety of problems on several areas. Therefore, the development of good non-toxic biocompatible biomaterials with a low elastic modulus is necessary. Particularly, hydroxyapatite (HA) is an attractive material for human tissue implantation. This material is widely used as artificial bone due to its good biocompatibility and similar composition to human bone. Many scientists have studied the fabrication of HA as a biomaterial. However, applications of bulk HA compact are hindered by the low strength of HA when it is sintered. Therefore, HA has been coated on Ti or Ti alloy to facilitate good bonding between tissue and the HA surface. However, there are many problems when doing this, such as the low bonding strength between HA and Ti due to the different thermal expansion coefficients and mechanical properties. In this study, a Ti-HA composite with a porous surface was successfully fabricated by pulse current activated sintering (PCAS) and a subsequent leaching process.

• Korean Journal of Metals and Materials
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• v.47 no.8
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• pp.508-515
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• 2009

Ti-6Al-4V biomaterial is widely used as a bone alternative. However, Ti-6Al-4V ELI alloy suffers from numerous problems such as a high elastic modulus and high toxicity. Therefore, non-toxic biomaterials with low elastic moduli need to be developed. Ti-HA(hydroxyapatite) composites were fabricated in the present work by pulsed current activated sintering (PCAS) at $1000^{\circ}C$ under 60 MPa using mixed Ti and HA powders. The effects of HA content on the physical and mechanical properties of the sintered Ti-HA composites have been investigated. X-ray diffraction(XRD) analysis of the Ti-HA composites, including Ti-40 wt%HA in particular, revealed new phases, $Ti_{2}O$, CaO, $CaTiO_3$, and TixPy, formed by chemical reactions between Ti and HA during sintering. The hardness of the Ti-HA composites decreased with an increase in HA content. The corrosion resistance of these composites was observed to be an excellent candidate as a commercial Ti-6Al-4 V ELI alloy. A Ti-5 wt%HA composite fabricated by PCAS is recommended as a new biomaterial, because it offers good corrosion resistance, compressive strength, wear resistance, and biocompatibility, and a low Young's modulus.

• Korean Journal of Metals and Materials
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• v.46 no.4
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• pp.223-226
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• 2008

The comparison of sintering behavior and mechanical properties of ultra-fine WC-10wt.%Co and WC-10wt.%Fe hard materials produced by high-frequency induction heated sintering (HFIHS) was accomplished using ultra fine powder of WC and binders(Co, Fe). The advantage of this process allows very quick densification to near theoretical density and prohibition of grain growth in nano-structured materials. Highly dense WC-10Co and WC-10Fe with a relative density of up to 99% could be obtained with simultaneous application of 60 MPa pressure and induced current within 1 minute without significant change in grain size. The hardness and fracture toughness of the dense WC-10Co and WC-10Fe composites produced by HFIHS were investigated.

• Journal of radiological science and technology
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• v.43 no.6
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• pp.443-451
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• 2020

This study is to evaluate absorbed dose from right lung for brachytherapy and to estimate the effects of tissue heterogeneities on dose distribution for Iridium-192 source using Monte Carlo simulation. The study employed Geant4 code as Monte Carlo simulation to calculate the dosimetry parameters. The dose distribution of Iridium-192 source in solid water equivalent phantom including aluminium plate or steel plate inserted was calculated and compared with the measured dose by the ion chamber at various distances. And the simulation was used to evaluate the dose of gamma radiation absorbed in the lung organ and other organs around it. The dose distribution embedded in right lung was calculated due to the presence of heart, thymus, spine, stomach as well as left lung. The geometry of the human body was made up of adult male MIRD type of the computational human phantom. The dosimetric characteristics obtained for aluminium plate inserted were in good agreement with experimental results within 4%. The simulation results of steel plate inserted agreed well with a maximum difference 2.75%. Target organ considered to receive a dose of 100%, the surrounding organs were left the left lung of 3.93%, heart of 10.04%, thymus of 11.19%, spine of 12.64% and stomach of 0.95%. When the statistical error is performed for the computational human phantom, the statistical error of value is under 1%.