• Resources Recycling
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• v.26 no.1
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• pp.43-50
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• 2017

In the present study, the multiple light scattering method was used for analysis of early hardening behavior of natural hydraulic lime (NHL) containing inorganic additives. In order to improve the properties of self-manufactured NHL, blast furnace slag and three types of gypsum were mixed with mixing ratio, and a water/solid ratio of fresh NHL paste was fixed 0.6. The fresh pastes in flat-bottomed cylindrical glass tubes were placed in the instrument. The backscattering flux (BS) of light from fresh pastes was then periodically measured at 10 minutes intervals the entire length of the sample (55mm) at $23^{\circ}C$ for 24 hours. The rate of increase of BS, slope of a linear equation to the mean value of BS (%) as a function of hydration time, was increased from 0.02 to 0.38 BS %/hour due to addition of blast furnace slag and gypsum. In the case of addition of hemi-hydrate, BS (%) and rate of increase in BS were highest.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.4.1-4.1
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• 2009

The dream of futurists andtechnologists is to build complex, multifunctional machines so small that theycan only be seen with the aid of a microscope. The unprecedented technologyadvancements in miniaturizing integrated circuits on semiconductors, and theresulting plethora of sophisticated, low cost electronic devices demonstratethe impact that micro/nano scale engineering can have when applied only to thearea of electrical and computer engineering. Emerging research efforts indeveloping organic and inorganic nano materials together with using micro/nanofabrication techniques for implementing integrated multifunctional devices hopeto yield similar revolutions in other engineering fields. By cross linking theindividual engineering fields through micro/nano technology, various organicand inorganic materials and miniaturized system devices can be developed thatwill have future impacts in the IT and life science applications. Yet to buildthe complex micromachines and nanomachine of the future, engineering will needto develop the technology capable of seamlessly integrating these materials andsubsystems together at the micro and nano scales. The micromachines of thefuture will be “integrated nanosystems,” complex devices requiring the integration of multiple materials,phenomena, technologies, and functions at the same platform. To develop thistechnology will require great efforts in materials science and engineering, infundamental and applied sciences. In this talk, we will first discuss thenature of micro and nanotechnology research for IT and life sciences, and thenintroduce selected current activities in micro and nanotechnology research fororganic and inorganic materials and devices. The newly developed micro/nanofabrication processes and devices, combined with in-depth scientificunderstandings of materials, can lead to rapid development of next generationsystems for applications in IT and life sciences.

• Journal of the Korean housing association
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• v.10 no.2
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• pp.223-234
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• 1999

The purpose of this study was to provide basic information for future residential flooring planning by identifying differences in preference for flooring materials of livingroom by characteristics of housewives living in apartment housing and by describing their perception of residential flooring materials and by analyzing their degree of satisfaction with the current flooring materials of livingroom. For this purpose, a survey was conducted by 281 housewives who lives in apartment, and analyzed by using frequency, percentage, mean, factor analysis, χ² test, t-test, one-way ANOVA and Duncan's Multiple Range test. The results of the study were obtained as follows: 1) The most preferred flooring materials was wood in the livingroom. Also, most of the reasons for preferred this flooring materials were good for health and good texture. 2) As a result of typifying housewives' perceptions of residential flooring materials, it was classified into fashoin-pursuit type, personality-expression type, beauty-pursuit type, health-pursuit type and practicality-pursuit type. 3) In the degree of satisfaction with the current flooring materials of livingroom, wood showed the highest level of satisfaction. 4) Differences in the degree of satisfaction with the current flooring materials of livingroom by personal characteristics of residents were analyzed. As results, it was found that the group who were later stage of family life cycle and experienced in replacing the flooring materials showed higher degree of satisfaction with the current flooring materials of livingroom.

• Tunnel and Underground Space
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• v.2 no.1
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• pp.164-176
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• 1992

The conical-ended borehole technique and hemispherical-ended borehole technique are proposed, for the accurate stress measurement within a rock mass. Theory of stress tensor determination and in situ measurement system are presented with successful case examples, and the characteristics of stress distribution within rock masses are examined by the multiple times measurement in a single borehole. Subsequently, the problem in relation to the numerical approach for cavern designing is discussed on the basis of the dependency of the stress discontinuity on the geological discontinuities and so on.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.217-220
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• 2004

본 논문에서는 다중 wedge와 방음벽에 의한 음파의 회절을 예측하는 공식을 다루었으며 BEM이나 다른 측정결과와 비교하여 정확성을 확인하였다. 여러 가지 경우의 회절경로가 있을 때 가장 적은 수의 회절경로를 따라 전파하는 음파가 가장 중요한 성분이며 회절수가 커질수록 크기는 줄어든다.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.317-320
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• 2004

본 논문에서는 2004 년도 춘계학회에 발표한 다중 wedge와 방음벽에 의한 음파의 회절 계산방법[1]을 여러가지 형태의 방음벽에 적용하였으며 BEM과 비교하여 정확성을 확인하였다. 상단 일부가 꺾인 방음벽에 대해 꺾는 각도, 길이변화에 따른 삽입손실을 계산하였으며 여러가지 높이의 수음점에 대해 회절을 계산하였다.

• Particle and aerosol research
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• v.14 no.3
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• pp.49-63
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• 2018

During the last decade, electrospray (ES) techniques have been used as potential methods for preparing of core-shell materials. Depending on the architecture of nozzle and design of devices, the ES techniques includes monoaxial, coaxial, multiple coaxial nozzle ES and microfluidic ES devices. ES operates based on a basic principle, in which a spray of monodisperse droplets is formed by dispensing an electrically conductive liquid through a capillary charged to a sufficiently high potential. In review of many recent research papers, we take a closer look at ES techniques and their applications for fabrication of core-shell materials. Several advantages of ES technique compared with other methods were emphasized and it may be regarded as a potential tool for fabrication of core-shell materials current and near future.

• Journal of Surface Science and Engineering
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• v.38 no.6
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• pp.212-215
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• 2005

Novel continuous electroforming process equipped with a rotating patterned mandrel, soluble/insoluble anode and multiple stage of rolling wheels was proposed to produce precision nickel mesh, which is known as a very efficient electromagnetic interference (EMI) shielding material. Continuously electroformed nickel deposits showed a tendency to form small-sized particles as the plating solution temperature increased and mandrel rotation speeded up and the applied current density decreased. Along the honeycomb patterns of mandrel, nickel was accurately electrodeposited on the surface of rotating mandrel, but quite different visual/structural characteristics were measured on both sides.

• Smart Structures and Systems
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• v.7 no.3
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• pp.223-228
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• 2011

An understanding of biomaterials' smart properties and how biocomposite materials are manufactured by cells provides not only bio-inspiration for new classes of smart actuators and sensors but also foundational technology for smart materials and their manufacture. In this case study, I examine the unique smart properties of bone, which are evident at multiple length scales and how they provide inspiration for novel classes of mechanoactive materials. I then review potential approaches to engineer and manufacture bioinspired smart materials that can be applied to solve currently intractable problems such as the need for "smart" body armor or decor cum personal safety devices.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.148-150
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• 2009

We have developed 15 inch, 130 blocks local dimming FEL using printed CNT emitters, in which multiple FE blocks were built with a common gate electrode. Cathode electrode formed by the double-metal technique, in which an insulator is interposed between the addressing bus and cathode electrode.