• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.364-365
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• 2006

Nanostructured or partially amorphous Al-and Zr-based alloys are attractive candidates for advanced high-strength lightweight materials. Such alloys can be prepared by quenching from the melt or by powder metallurgy using mechanical attrition techniques. This work focuses on mechanically attrited powders and their consolidation into bulk specimens. Selected examples of mechanical deformation behavior are presented, revealing that the properties can be tuned within a wide range of strength and ductility as a function of size and volume fraction of the different phases.

• 한국콘텐츠학회논문지
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• 제21권5호
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• pp.477-487
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• 2021

본 연구는 발달장애인을 위한 읽기쉬운자료 개발 교육 시 활용할 수 있는 교재를 개발하는 것을 목적으로 하였다. 교재는 국내외 읽기 쉬운 자료 제작 지침서 분석, 차시 확인 및 교재 내용 개발, 타당도 검증의 단계를 거쳐 개발하였다. 최종 개발된 자료는 독자 구분, 어휘, 상징, 레이아웃, 제작 실습을 포함하여 총 7차시의 교재로 개발하였다. 본 연구에서 개발된 교재의 중요한 특성은 첫째, 국내 최초로 읽기 쉬운 자료를 읽는 독자를 분류하여 보통 읽기(Plain Language) 독자, 읽기 쉬운(Easy to Read) 독자로 소개하였다. 둘째, 읽기 쉬운 자료를 개발하면서 참고할 수 있는 지침을 체크리스트로 개발하여 스스로 점검할 수 있도록 구성하였다. 셋째, 주제별 활동지와 워크북을 개발하여 활동 중심 교재로 활용할 수 있도록 구성하였다.

• 정보관리학회지
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• 제40권3호
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• pp.197-219
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• 2023

자료를 기술하기 위해 일반적으로 활용하는 AACR 계열의 목록규칙과 서지구조는 한국의 고문헌만이 지니고 있는 서지적 특성을 구체적으로 반영하는 것에 한계를 보이고 있다. 이에 본 연구에서는 고문헌의 서지적 측면을 분석하고 FRBR LRM 개념적 모형을 기반으로 기술항목 사이의 관계를 형성하여 고문헌의 고유한 특성에 최적화된 서지구조를 제안하였다. 이때 관계의 설정은 관련된 고문헌을 서지적으로 연결시켜 줄 수 있는 방향으로 이루어져야 하며, 이를 위해서는 고문헌, 특히 우리나라의 고문헌이 지닌 서지적 특성과 형태적, 내용적 변형을 충분하게 반영할 수 있는 관계의 형성이 설정되어야 한다. 단위저록 형태의 단편적인 서지레코드만을 생성하는 기존의 서지 환경에서 벗어나 LRM 구조를 적용함으로써 서지데이터 단위로 기술항목을 분리 및 통합하는 것이 가능해진다. 이를 통해 새로운 서지적 환경을 마련함으로써 고문헌의 조직, 관리, 활용을 보다 효율적으로 할 수 있게 되며, 향후 BIBFRAME 형식의 서지데이터 생성 기반을 마련할 수 있다.

• 한국안전학회지
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• 제31권6호
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• pp.32-38
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• 2016

In general, lots of containers including various dangerous materials are transported to the port located in big cities such as Busan where massive residents live. Thus, it's really important how to make the emergency response for the leak accidents of dangerous materials and evaluate the direct or indirect damages to adjacent areas. In this study, in order to make reasonable emergency plans, CA (Consequence Analysis) is employed after selecting a key hazardous and noxious material, hydrogen fluroide. This material accounts for the third largest portion of cargo volume among all dangerous materials and can cause a huge damage in case of leakages. As a case study, Busan North port is selected as a test port since the portion of dangerous materials is higher than that of other ports in Busan. It is assumed that 1 ton of hydrogen fluoride is spilled at Busan North port. CA is performed to assess the impact of this accident. Throughout CA, the ERPG-2 range of a leak accident can be evaluated and this result can be used for decision making tools for mitigating the impact of a leak accident. To mitigate the damage of this accident, suitable a protective equipment and resident evacuation procedures should be prepared. Finally, this study can provide a systematic approach to make the emergency plan for reducing economical and personal losses.

• 대한금속재료학회지
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• 제49권6호
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• pp.425-439
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• 2011

A review of the development history of interatomic potential models for ionic materials was carried out paying attention to the way of future development of an interatomic potential model that can cover ionic, covalent and metallic bonding materials simultaneously. Earlier pair potential models based on fixed point charges with and without considering the electronic polarization effect were found to satisfactorily describe the fundamental physical properties of crystalline oxides (Ti oxides, $SiO_2$, for example) and their polymorphs, However, pair potential models are limited in dealing with pure elements such as Ti or Si. Another limitation of the fixed point charge model is that it cannot describe the charge variation on individual atoms depending on the local atomic environment. Those limitations lead to the development of many-body potential models(EAM or Tersoff), a charge equilibration (Qeq) model, and a combination of a many-body potential model and the Qeq model. EAM+Qeq can be applied to metal oxides, while Tersoff+Qeq can be applied to Si oxides. As a means to describe reactions between Si oxides and metallic elements, the combination of 2NN MEAM that can describe both covalent and metallic elements and the Qeq model is proposed.

• 대한기계학회논문집A
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• 제32권11호
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• pp.918-923
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• 2008

Since crack detection for laminated composites in-service is effective to improve the structural reliability of laminated composites, it have been tried to detect cracks of laminated composites by various nondestructive methods. An electric potential method is one of the widely used approaches for detection of cracks for carbon fiber composites, since the electric potential method adopts the electric conductive carbon fibers as reinforcements and sensors and the adoption of carbon fibers as sensors does not bring strength reduction induced by embedding sensors into the structures such as optical fibers. However, the application of the electric method is limited only to electrically conductive composite materials. Recently, a piezoelectric method using piezoelectric characteristics of epoxy adhesives has been successfully developed for the adhesive joints because it can monitor continuously the damage of adhesively bonded structures without producing any defects. Polymeric materials for the matrix of composite materials have piezoelectric characteristics similarly to adhesive materials, and the fracture of composite materials should lead to the fracture of polymeric matrix. Therefore, it seems to be valid that the piezoelectric method can be applied to monitoring the damage of composite materials. In this research, therefore, the feasibility study of the damage monitoring for composite materials by piezoelectric method was conducted. Using carbon fiber epoxy composite and glass fiber composite, charge output signals were measured and analyzed during the static and fatigue tests, and the effect of fiber materials on the damage monitoring of composite materials by the piezoelectric method was investigated.

• Corrosion Science and Technology
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• 제5권3호
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• pp.106-111
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• 2006

Painting has protected metallic stack but the paint films may be degraded and corrosion problem can be arisen. To protect the painted metal stack, cathodic protection can be applied. If cathodic protection is applied to bare metal, only small area may be protected. However, if cathodic protection is applied to painted metal surface, large area can be protected and the lifetime of paint films can be extended. High corrosion resistant alloys were corroded at a Flue Gas Desulfurization (FGD) facility of power plant within a short period and thus cathodic protection can be used to protect these metals. On the base of computer simulation, if cathodic protection is applied to bare metal in a FGD environment, it was estimated that applied current could almost be spent to protect area near the anode. However, if cathodic protection is applied to high resistant-coated metal, the much larger area from the anode could be effectively protected.

• 한국입자에어로졸학회지
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• 제12권3호
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• pp.73-80
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• 2016

Bioaerosol inactivation becomes important as people recognize the significance on the health effects of bioaerosols. There are several ways to inactivate such bioaerosols such as antimicrobial filters, UV, etc. For the on-filter-inactivation, proper antimicrobial materials coating should be applied. Recently, air ions are adopted to effectively reduce germ and virus activity. Limitations arise when each method is applied separately. Coating materials can experience chemical instability over time and temperature. Ionizers can generate ozone to prepare high ion concentrations. Combinations of developed techniques to enhance the inactivation efficiency were suggested. Researches on the air sterilization are reviewed and outlook is highlighted. Proper techniques such as combinations of filter material coating and air ion generation can be used to make air quality better for human living.

• Korean Chemical Engineering Research
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• 제45권6호
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• pp.536-546
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• 2007

나노 미립자는 부피대비 높은 표면적을 가지고 있기 때문에 벌크 상태에서는 볼 수 없는 여러 흥미로운 성질들을 가지고 있다. 나노 미립자들은 나노 구조체 재료, 산업용 재료 혹은 촉매 재료 등을 제조하는데 사용될 수 있다. 기상공정에 의해 높은 단분산성을 갖는 다양한 크기의 나노 미립자를 제조할 수 있으며 제조된 미립자는 각종 첨단 기능성 재료의 원료로 이용될 수 있다. 본고에서는 기상공정을 통하여 나노 미립자 제조에 이용되는 에어로솔 반응기들을 소개하였으며 각 반응기의 특성을 분석하였고 기상 공정에 의한 미립자 제조에 관련된 최근 흥미 있는 연구들을 소개하도록 하였다.

• 한국재료학회지
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• 제32권3호
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• pp.115-124
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• 2022

Porous basalt aggregate is commonly used in roadbed engineering, but its application in concrete has rarely been studied. This paper studies the application of porous basalt in concrete. Porous basalt aggregate is assessed for its effects on mechanical strength and durability of prepared C50 concrete; because it has a hole structure, porous basalt aggregate is known for its porosity, and porous basalt aggregates can be made full of water through changing the content of saturated basalt; after full-water condition is achieved in porous basalt aggregate mixture of C50 concrete, we discuss its mechanical properties and durability. The effects of C50 concrete prepared with basalt aggregate on the compressive strength, water absorption, and electric flux of concrete specimens of different ages were studied through experiments, and the effects of different replacement rates of saturated porous basalt aggregate on the properties of concrete were also studied. The results show that porous basalt aggregate can be prepared as C50 concrete. For early saturated porous basalt aggregate concrete, its compressive strength decreases with the increase of the replacement rate of saturated aggregate; this occurs up to concrete curing at 28 d, when the replacement rate of saturated basalt aggregate is greater than or equal to 40 %. The compressive strength of concrete increases with the increase of the replacement rate of saturated aggregate. The 28 d electric flux decreases with the increase of the replacement rate of saturated aggregate, indicating that saturated porous basalt aggregate can improve the chloride ion permeability resistance of concrete in later stages.