• Journal of the Korean Ceramic Society
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• v.39 no.7
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• pp.675-679
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• 2002

To produce a strengthened glass, single ion exchange properties such as three-point bend strength and residual stress were investigated in soda-lime-silicate substrate glass for display use. The present work showed that the maximum value of strength was 62.5${\times}$10$\sub$6/ kg/㎡ after, the two-step single ion exchange process at 470$^{\circ}C$ for 1 h and 450$^{\circ}C$ for 24 h. As the result of the fracture analysis after bending test, the residual stress on the fractured surface of the strengthened glass increased the flexibility by means of absorbing the elastic deformation energy in the glass. Also, the effects of absorbing the elastic deformation energy were analysed by curvature change, number of multiple crack branches and brittleness.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.5
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• pp.533-543
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• 2016

Supplying clean and safe water to people is facing both quantitative and qualitative challenges. Due to climate change, access to freshwater becomes increasingly difficult, while pollution from various sources decreases the public trust in water quality. Managed aquifer recharge (MAR) which stores and uses surface water in aquifer is receiving attention as a new technology to secure freshwater. Recently, there is a global expansion in the attempt to combine general purification plants and hazard analysis and critical control point (HACCP) which manages all the process from raw material to consumer for food safety. This research is about an attempt to apply HACCP to the drinking water supply process using MAR to secure both quantity and quality of drinking water. The study site is a MAR plant being constructed in the downstream area of the Nakdong River Basin, South Korea. The incorporation of HACCP with MAR-based water supply system is expected to enhance the safety and reliability of drinking water.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.1013-1014
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• 2006

Mobilecomputer offers more fundamental role than role assistance enemy of modern technology equipment and new Information Technology can reconsider, and reconstruct creatively accuracy of physiological concept. That military register symptoms are developed of disease, before far before rehalibitation, offer possibility that can intervene in process that motive change of military register symptoms after rehalibitation. But, that many parameters become analysis target and mathematical settlement and equalization system of neted data of that is huge, same time collection of all datas can lift difficulty etc.. These main weakness puts in structural relation between elements that compose system. Therefore, dynamics research that time urea of systematic adjustment has selected method code Tuesday nerve dynamics enemy who groping of approach that become analysis point is proper and do with recycling bioelectricity signal. Nature model of do living body signal digital analysis chapter as research result could be developed and scientific foundation groping could apply HSS (Hardware-software system) by rehalibitation purpose. Special quality that is done radish form Tuesday of bioelectricity signal formation furthermore studied, and by the result, fundamental process of bodysignal in do structure circuit form of analog - digital water supply height modelling do can

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.5
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• pp.514-520
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• 2009

Titanium is one of the most attractive materials due to their superior properties of high specific strength and excellent corrosion resistance. The applications in aerospace and medical industries demand machining process more frequently to obtain more precise products. Machining of titanium is faced with strong challenges such as increased component complexity i.e. airframe components manufacturing processes. The machining cost on titanium have traditionally demanded high cutting tool consumable cost and slow machining cycle times. Similarly, the high wear of the cutting tools restricts the cutting process capabilities. Titanium screws applied to fasten parts In the several corrosion environment. In the thread cutting of titanium alloys, the key point for successful work is to select proper cutting methods and tool materials. This study suggests a guidance fur selecting the cutting methods and the tool materials to improve thread quality and productivity. Some experiments investigate surface roughnesses, cutting forces and tool wear with change of various cutting parameters including tool materials, cutting methods, cutting speed. As the results, the P10 type insert tip was assured of the best for thread cutting of Ti-6Al-4V titanium alloy. Also the initial depth of infeed was desirable to use the value below 0.5mm as the uniform cutting area method is applied.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.4
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• pp.577-588
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• 1995

A numerical study is made on the melting process of an unconstrained ice inside an isothermal ice-ball capsule. The unmelted ice core is continuously ascending on account of buoyancy forces. Such a buoyancy-assisted melting is commonly characterized by the existence of a thin liquid film above the ice core. The present study is motivated to present a full-equation-based analysis of the influences of the initial subcooling and the natural convection on the fluid flow associated with the buoyancy-assisted melting. In the light of the solution strategy, the present study is substantially distinguished from the existing works in that the complete set of governing equations in both the melted and unmelted regions are resolved in one domain. Numerical results are obtained by varying the wall temperature and initial temperature. The present results reported the transition of the flow pattern in a spherical capsule, as the wall temperature was increased over the density inversion point. In addition, time wise variation of the shapes for the liquid film and the lower ice surface, the time rate of change in the melt volume fraction and the melting distance at symmetric line is analyzed and is presented.

• Journal of the Korean Ceramic Society
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• v.47 no.5
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• pp.439-444
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• 2010

The usual ceramic process of mixing and milling in state of oxide of $ZrO_2$ and $CeO_2$ was adopted in wet process to manufacture Ce-TZP in this study. The maximum dispersion point of every slurry manufactured with mixture of $ZrO_2$ and $CeO_2$ was neat at pH10. The stable slurry in average particle size of 90 nm can be manufactured when it is dispersed with use of ammonia water and polycarboxylic acid ammonium. The sintered Ce-TZP ceramics manufactured with addition of $CeO_2$ less than 10 mol% was progressed to the fracture of specimen due to the monoclinic phase existence more than 30% at the room temperature. More than 99% of tetragonal phase was created for the sintered body with addition of $CeO_2$ beyond 18 mol%, but the mechanical property degrade on the entire specimen was brought due to the $CeO_2$ existing above 3%. Consequently, the optimal Ce-TZP combined in oxide state was identified in 16 mol% of $CeO_2$ contents.

• Korean Institute of Interior Design Journal
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• v.19 no.1
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• pp.75-84
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• 2010

This study will establish the transformal characteristics of architectural visual information by investigating: how contemporary architects perceive and process multifaceted architectural information via the expression media since 1970s. The purposes and results of this study are summarized as follows: This study established the contemporary transformal characteristics by comparing the expression methods of traditional architects with the transformal characteristics of visual information derived from the contemporary architectural expression media. In a pluralistic information society, the expression methods of the past, which recognize space as a stationary, unidimensional visual point on a drawing surface, is now changing to the mixed, multidimensional expression methods that connect various visual points on a limited drawing surface. Furthermore, the rapid advancement of digital media is changing, from a method which simply arranges visual information, to a flexible visual tool which can process architecture sequentially and simultaneously. As the communication structure of architecture is moving toward an individual-centered two-way communication type, the information delivery method is used to visualize conceptual, inferential information, rather than visualizing realistic information which simply records facts. In the past, multidimensional, non-linear forms could not be processed by the conventional design processes and sketch work, but now they can be expressed via digital media.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.221-223
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• 1999

In this work, samples were manufactured variously by changing conventional calcining and sintering conditions and we tried the utilization by making the heat treatment time, which is demanded to high-Tc phase formation, much shorter. We found out optimal heat treatment conditions with the analysis on formation process at superconducting phase in term of the change of calcining and sintering time and then, examined X-ray diffraction(XRD) patterns, scanning electron microscope(SEM) measurement and energy dispersive X-ray spectrometer(EDX) of the samples manufactured under heat treatment conditions which we suggest here. As a result, 2223 high-$T_c$, phase of (Bi,Pb)SrCaCuO superconductor starting with ($Bi_l$ xPbx,)$_2$$Sr_2$$Ca_2$$Cu_3$$O_y$, composition was formed from 1 hr sintering sample at temperature nearby melting point and also the completed sample with calcining and sintering time of 9 hr was formed high-$T_c$.low-$T_c$ phase appearing in sight above the critical temperature of liquid $N_2$.

• Korean Journal of Materials Research
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• v.30 no.7
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• pp.338-342
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• 2020

Tin oxide (SnO₂) nanocrystals are synthesized by a thermal evaporation method using a mixture of SnO₂ and Mg powders. The synthesis process is performed in air at atmospheric pressure, which makes the process very simple. Nanocrystals with a belt shape start to form at 900 ℃ lower than the melting point of SnO₂. As the synthesis temperature increases to 1,100 ℃, the quantity of nanocrystals increases. The size of the nanocrystals did not change with increasing temperature. When SnO₂ powder without Mg powder is used as the source material, no nanocrystals are synthesized even at 1,100 ℃, indicating that Mg plays an important role in the formation of the SnO₂ nanocrystals at temperatures as low as 900 ℃. X-ray diffraction analysis shows that the SnO₂ nanocrystals have a rutile crystal structure. The belt-shaped SnO₂ nanocrystals have a width of 300~800 nm, a thickness of 50 nm, and a length of several tens of micrometers. A strong blue emission peak centered at 410 nm is observed in the cathodoluminescence spectra of the belt-shaped SnO₂ nanocrystals.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.686-693
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• 2022

Construction is a collaborative endeavor. The complexity in delivering construction projects successfully is impacted by the effective collaboration needs of a multitude of stakeholders throughout the project life-cycle. Technologies such as Building Information Modelling and relational project delivery approaches such as Alliancing and Integrated Project Delivery have developed to address this conundrum. However, with the onset of the pandemic, the digital economy has surged world-wide and advances in technology such as in the areas of machine learning (ML) and Artificial Intelligence (AI) have grown deep roots across specializations and domains to the point of matching its capabilities to the human mind. Several recent studies have both explored the role of AI in the construction process and highlighted its benefits. In contrast, literature in the organization studies field has highlighted the fear that tasks currently done by humans will be done by AI in future. Motivated by these insights and with the understanding that construction is a labour intensive sector where knowledge is both fragmented and predominantly tacit in nature, this paper explores the integration of AI in construction processes across project phases from planning, scheduling, execution and maintenance operations using literary evidence and experiential insights. The findings show that AI can complement human skills rather than provide a substitute for them. This preliminary study is expected to be a stepping stone for further research and implementation in practice.