• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.4
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• pp.50-56
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• 2012

Rotor system is a very important part which produce lift, thrust and control force in helicopter. Component of rotor system must have structural integrity for applied load. The estimation of structural integrity is regarded greatly as important in aerospace field. In this study, the process of structural analysis performed for bearingless main rotor system of helicopter. The composite flexbeam and torque tube of bearingless main rotor are very thick, so 3D layered soild elements of MSC.PATRAN were used to get the finite element analysis results. To estimate structural integrity, non-linear static analysis considering geometric non-linearity is performed. In addition, detailed finete element analysis and non-linear static analysis are performed to consider the stress concentration for fitting effect and contact surface. The estimation process of structural integrity for bearingless main rotor system of helicopter may help the design.

• Journal of the Korean Geographical Society
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• v.46 no.2
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• pp.212-232
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• 2011

The main objective of this study is to establish a population projection method based on the biregional cohort-component method and to apply it to population projections for Busan. Some drawbacks of using the net migration cohort-component method in a regional or local level population projection are demonstrated. A biregional cohort-component method, a variant of the interregional cohort-component method, is established as an alternative where in-migration and out-migration are separately considered and then are combined to produce a projection for the migration component. Predicated on the established method, population projections for Busan are undertaken for the period of 2005~2030 under three different scenarios. Considerably different projection results are obtained between the net migration and biregional methods; among others, the trend of population decline is more severe in the former than in the latter. An investigation of the temporal trend of the projected population shows that the proposed method is highly reasonable. In conclusion, the proposed method based on the biregional cohort-component method seems not only to be theoretically more robust than the net migration cohort-component method but also to be very effective in the real world application.

• Herbal Formula Science
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• v.23 no.1
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• pp.25-53
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• 2015

This report describes 90 prescriptions related to the use of Ostericum Radix(OR) blended as the main ingredient in the Dongeuibogam.

The following conclusions were reached through investigations on the prescriptions that use OR as a key component.

Prescriptions where OR was used as one of the monarch(drug) utilized for 27 therapeutic purposes in total.

It was searched that the frequency of prescriptions in the therapeutic purposes were as follows. The chapter of eyes is 22.2%, the wind is 13.4%, the child 11.1%, the cold is 8.9%, the head is 6.7%, the malaria disease 4.5% in the order.

Prescriptions that utilized OR as the main ingredient were most used for treating diplopia, facial nerve palsy, headache and a fever in the whole body. These were also used for treating 55 different types of diseases.

The dosage of OR in formulas was ranging from 2pun(about 0.75g) to 2don(about 7.5g). However, 1don(about 3.75g) was most used for clinical application.

We can find out that according to herbs or prescriptions blended with itself, OR made a variety of functions to eliminate cold with wind, humidity, pain, and convulsions from the body. And also, Bangpungtang was the most useful base prescription which used OR as the main component.

• 한국문화재보존과학회:학술대회논문집
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• 2004.10a
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• pp.137-153
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• 2004

We have analyzed the ingredients of 17 pieces of Bronze Age bronze ware, and an additional 22 pieces of Koryo and Chosun dynasty bronze ware. We have also conducted analysis of the extraction sites where these bronze ware items were found. For analyzing the main ingredient the bronze ware items have been divided into 3 groups - Cu-Sn(70?75:20), Cu-Pb-Sn(70:10:10), Cu-Pb-Sn(60:10:20) type respectively. In tile cases of the Cu-Pb-Sn groups the division comes down to differences in the Cu content as the main component, and elements such as Ni, Fe, Co contribute as a micro ingredient. The geographical and periodic characteristics of ancient bronze ware items show that theircompositional element changes from Cu:Sn to Cu:Pb:Sn and the Cu content decreases with the period,while the Pb content increases with the period. Bronze ware items from Suchon Ri, Gongju (that were used in 3 B.C.) form very different categories from 3rd ${\~}$ 2nd B.C.. They additionally formed very different categories from those bronze ware items analyzed in this research. These bronze ware itemsare shown to be geographically close and periodically overlapped, but made of a new elemental composition. This shows an inflow of a production technical culture present in the new bronze wares. The main component content of Cu is lower, and the Co and Fe contents (as microelements) are much higher than that of other bronze ware items. Such facts showthat those bronze ware items used completely different materials from bronze ware items in other cultural areas, or that there were differences in smelting techniques In the places where ancient bronze ware items have been extracted, it is presumed that the materials originated from the southern parts of Korea andnorthern parts and southern parts of China. .As more bronze ware scientific research is compiled one can conclude that that there will be enough scientific evidence to study the Bronze Age culture of Koreasystematically.

• Nuclear Engineering and Technology
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• v.54 no.7
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• pp.2720-2727
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• 2022

The Generation IV Lead-cooled fast reactor (LFR) take the liquid lead or lead-bismuth eutectic alloy (LBE) as the coolant of the primary cooling circuit. Combined with the natural characteristics of lead alloy and the design features of LFR, the system is the simplest and the number of equipment is the least, which reflects the inherent safety characteristics of LFR. The nuclear main coolant pump (MCP) is the only power component and the only rotating component in the primary circuit of the reactor, so the various operating characteristics of the MCP are directly related to the safety of the nuclear reactor. In this paper, various working conditions that may occur in the normal rotation (positive rotating) of the MCP and the corresponding internal flow characteristics are analyzed and studied, including the normal pump condition, the positive-flow braking condition and the negative-flow braking condition. Since the corrosiveness of LBE is proportional to the fluid velocity, the distribution of flow velocity in the pump channel will be the focus of this study. It is found that under the normal pump condition and positive-flow braking conditions, the high velocity region of the impeller domain appears at the inlet and outlet of the blade. At the same radius, the pressure surface is lower than the back surface, and with the increase of flow rate, the flow separation phenomenon is obvious, and the turbulent kinetic energy distribution in impeller and diffuser domain shows obvious near-wall property. Under the negative-flow braking condition, there is obvious flow separation in the impeller channel.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.5
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• pp.373-379
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• 2020

In this study, TiN-coated cBN (cubic-structure boron nitride) powders were successfully synthesized by a sol-gel method using titanium (IV) isopropoxide (TTIP) and by controlling the heat treatment conditions. After the sol-gel process, amorphous nano-sized TiO_x was uniformly coated on the surface of cBN powder particles. The obtained TiO_x-coated cBN powders were heated at 1,000~1,300℃ for 1 or 6 h in a flow of 95%N₂-5%H₂ mixed gas. With increasing temperature, the chemical composition of the TiO_x coating layer changed in the order of TiO₂→Ti₆O₁₁→Ti₄O₇→TiN due to reduction of the Ti ions. The TiN coating layer was observable in the samples heated at 1,200℃ and appeared as the main phase in the sample heated at 1,300℃. The resulting thickness of the TiN coating layer of the sample heated at 1,300℃ was approximately 45~50 nm.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.695-701
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• 2014

The main objective of palliative treatment for cancer patients has been to maintain, if not improve, the quality of life (QoL). There is a lack of local data on satisfaction and QoL among cancer patients receiving palliative treatment in Malaysia. This study covers patients with incurable, progressive cancer disease receiving palliative treatment in a teaching hospital in Kuala Lumpur, comparing the different components of QoL and correlations with patient satisfaction. A cross-sectional survey using Malay validated SF36 QoL and PSQ-18 (Short Form) tools was carried out between July 2012 -January 2013 with 120 cancer patients receiving palliative treatment, recruited into the study after informed consent using convenient sampling. Results showed that highest satisfaction were observed in Communication Aspect ($50.6{\pm}9.07$) and the least in General Satisfaction ($26.4{\pm}5.90$). The Mental Component Summary ($44.9{\pm}6.84$) scored higher when compared with the Physical Component Summary ($42.2{\pm}7.91$). In this study, we found that patient satisfaction was strongly associated with good quality of life among cancer patients from a general satisfaction aspect (r=0.232). A poor significant negative correlation was found in Physical Component (technical quality, r=-0.312). The Mental Component showed there was a poor negative correlation between time spent with doctor (r=-0.192) and accessibility, (r=-0.279). We found that feeling at peace and having a sense of meaning in life were more important to patients than being active or achieving good physical comfort. More studyis needed to investigate patients who score poorly on physical and mental component aspects to understand their needs in order to achieve better cancer care.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.8
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• pp.1973-1980
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• 2015

The combat system has a different purpose depending on its mission. All functions of combat system are important, but, the components that related main functions for the purpose, are important than other components. Also, the hit probability of component is proportional to area of the component. Therefore, when we analyze vulnerability of combat system, to consider the importance and hit probability of component. Thus to improve reliability of combat system, we apply the analyzed result to design combat system. In this paper, we develop a vulnerability analysis program based on criticality which calculated from importance and hit probability of components by related researches. To do this, we propose a methodology to apply criticality of components, and define classification rates for calculating criticality based on FMECA. Additionally, we propose a technique of vulnerability analysis using criticality of components, and apply the proposed technique to develop and test the vulnerability analysis program for automation of analysis.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.4
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• pp.396-403
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• 2016

This study is based on the evaluation of a single component injection type adhesive repair material and a new 2 component type used in leakage of underground concrete structures. The studies showed that based on different mix ratio of the 2 component type adhesive sealant comprised of an asphalt main and latex mixture agent the viscosity of the material compound differed significantly. Based on a permeability testing, injection and economic efficiency, and performance, the appropriate ratio was determined to be 6:1 and was proceeded to the KS F 4935 evaluation method. The 2 component type adhesive sealant uses a static mixer and a cartridge type container for the injection procedure and was able to satisfy the evaluation criteria outlined in the KS F 4935 standard.

• The KIPS Transactions:PartD
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• v.8D no.6
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• pp.673-680
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• 2001

When the developers develop the software, the cost and time of the software development can be reduced by using blocks that are implemented previously. We call these implemented blocks components. In the early stage of Web-based Instruction, it didn't gain preference in spite of it's benefit of convenience. The main reason is, I think, the lack of generality at the education system which eventually results in unsatisfactory facilities compared with the requirement of teachers and students. And the early systems don't make good use of the plenty data in distributed environment, and don't show so good reliablity due to lack of systematic design and development. In this paper, we suggest WBI developing technology using the concept of WBSE. WBI developing is consist of component of pre-developed education software, integration of component using its reusability, and production of more requirement-satisfactory education software.