• Interaction and multiscale mechanics
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• v.7 no.1
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• pp.543-561
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• 2014

We present a full energy and force formulation of the quasicontinuum method with non-local and local transition elements. Non-local transition elements are developed to transmit inhomogeneity from the atomistic to the continuum regions. Local transition elements are developed to resolve the mathematical mismatch between non-local atoms and the local continuum. The rationale behind these transition elements is provided by analyzing the energy and force transitions between atoms and continuum under the Cauchy-Born rule. We show that breakdown of the Cauchy-Born rule occurs for slaved atoms of local elements within the cutoff of non-local atoms. The inadequacy of the Cauchy-Born rule at the transition region naturally leads to the need of atomistic treatment of transition slaved and transition representative atoms. Such an atomistic treatment together with a full or cutoff sampling allows non-local transition elements containing these transition entities to transmit inhomogeneity. Different force formulations for transition representative atoms and pure local representative atoms allow the local transition elements to resolve non-local and local mismatches. The method presented herein is validated by force calculations in an unstressed perfect crystal as well as an unrelaxed grain boundary model. A nanoindentation simulation in 3D is conducted to demonstrate the accuracy and efficiency of the proposed method.

• Environmental Engineering Research
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• v.18 no.1
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• pp.3-8
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• 2013

Collision cell technology-inductively coupled plasma-mass spectrometry (CCT-ICP-MS) was used to measure the concentrations of approximately 19 elements associated with airborne PM2.5 samples that were collected from a roadside sampling station in Daejeon, Korea. Standard reference material (SRM 2783, air particulate on filter media) of the National Institute of Standards and Technology was used for the quality assurance of CCT-ICP-MS. The elemental concentrations were compared statistically with the certified (or recommended) values. The patterns of distribution were clearly distinguished between elements with their concentrations ranging over four orders of magnitude. If compared in terms of enrichment factors, it was found that toxic trace elements (e.g., Sb, Se, Cd, As, Zn, Pb, and Cu) of anthropogenic origin are much more enriched in PM2.5 samples of the study site. To the contrary, the results of the correlation analysis showed that PM2.5 concentrations can exhibit more enhanced correlations with the elements (e.g., Fe, K, Si, and Ti) arising from earth's crust. The findings of strong correlations between PM2.5 and the elements of crustal origin may be directly comparable with the dominant role of those species by constituting a major fraction of even PM2.5 as well as PM10 at the roadside area.

• Animal cells and systems
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• v.5 no.2
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• pp.133-137
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• 2001

Long terminal repeats (LTRs) of the human endogenous retrovirus K family (HERV-K) have been found to be coexpressed with sequences of genes closely located nearby. We examined transcribed HERV-K LTR elements in human brain tissue. Using cDNA synthesized from mRNA of the human brain, we performed PCR amplification and identified ten HERV-K LTR elements. These LTR elements showed a high degree of sequence similarity (92.4-99.7%) with the human-specific LTR elements. A phylogenetic tree obtained by the neighbor-joining method revealed that HERV-K LTR elements could be divided into two groups through evolutionary divergence. Some HERV-K LTR elements (HKL-B7, HKL-B8, HKL-B10) belonging to the group II from human brain cDNA were closely related to the human-specific HERV-K LTR elements. Our data suggest that HERV-K LTR element are active in the human brain; they could conceivably play a pathogenic role in human diseases such as psychosis.

• Bulletin of the Korean Mathematical Society
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• v.56 no.1
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• pp.57-71
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• 2019

Let R be an associative ring with identity, M a t.u.p. monoid with only one unit and ${\omega}:M{\rightarrow}End(R)$ a monoid homomorphism. Let R be a reversible, M-compatible ring and ${\alpha}=a_1g_1+{\cdots}+a_ng_n$ a non-zero element in skew monoid ring $R{\ast}M$. It is proved that if there exists a non-zero element ${\beta}=b_1h_1+{\cdots}+b_mh_m$ in $R{\ast}M$ with ${\alpha}{\beta}=c$ is a constant, then there exist $1{\leq}i_0{\leq}n$, $1{\leq}j_0{\leq}m$ such that $g_{i_0}=e=h_{j_0}$ and $a_{i_0}b_{j_0}=c$ and there exist elements a, $0{\neq}r$ in R with ${\alpha}r=ca$. As a consequence, it is proved that ${\alpha}{\in}R*M$ is unit if and only if there exists $1{\leq}i_0{\leq}n$ such that $g_{i_0}=e$, $a_{i_0}$ is unit and aj is nilpotent for each $j{\neq}i_0$, where R is a reversible or right duo ring. Furthermore, we determine the relation between clean and nil clean elements of R and those elements in skew monoid ring $R{\ast}M$, where R is a reversible or right duo ring.

• Journal for History of Mathematics
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• v.34 no.1
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• pp.1-20
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• 2021

Logic and intuition are considered as the opposite extremes of teaching geometry, and any teaching method of geometry is to be placed between these extremes. The purpose of this study is to identify the characteristics of logical and intuitive approaches for teaching geometry and to derive didactical implications by taking Euclid's Elements and Clairaut's Elements respectively representing the extremes. To this end, comparing the composition and contents of each book, we analyze which propositions Clairaut chose from Euclid's Elements, how their approaches differ in definitions, proofs, and geometrical constructions, and what unique approaches Clairaut took. The results reveal that Clairaut mainly chose propositions from Euclid's books 1, 3, 6, 11, and 12 to provide the contexts that show why such ideas were needed, rather than the sudden appearance of abstract and formal propositions, and omitted or modified the process of justification according to learners' levels. These propose a variety of intuitive strategies in line with trends of teaching geometry towards emphasis on conceptual understanding and different levels of justification. Specifically, such as the general principle of similarity and the infinite geometric approach shown in Clairaut's Elements, we could confirm that intuition-based geometry does not necessarily aim for tasks with low cognitive demand, but must be taught in a way that learners can understand.

• Architectural research
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• v.24 no.2
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• pp.29-40
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• 2022

The transition from manufacturing to service-based economies in highly developed societies during the post-industrial period resulted in the decline of the industrial landscape, leaving it abandoned or underutilized. In pursuit of revitalizing the obsolete industrial space, innovative design techniques based on adaptive reuse are applied to retrofit modern functions to create a new cultural space and preserve the historical, symbolic, and cultural importance of the abandoned industrial facilities. Design considerations based on facade redesign have proven to be one of the most adopted techniques that can help in recreating a new function for the vacant industrial buildings and integrating them into the present-day urban fabric. This paper examines the facade renovation elements used for the adaptive reuse of 15 abandoned industrial buildings presently used as multi-purpose facilities in South Korea. Through a questionnaire survey, this study analyzes the respondents' preference for different facade renovation elements in the 15 sites according to age and gender. The study found that both genders showed similar preference patterns between most elements. But on some elements, females were keener and expressed a stronger opinion than males. There were much more females than males who perceived color and material as the most important exterior elements. The findings of this study can be used for the adaptive reuse of industrial buildings according to user preferences for different facade renovation elements.

• Structural Engineering and Mechanics
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• v.85 no.3
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• pp.315-335
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• 2023

Limited studies are available on the mathematical estimates of the compressive strength (CS) of glass fiber-embedded polymer (glass-FRP) compressive elements. The present study has endeavored to estimate the CS of glass-FRP normal strength concrete (NSTC) compression elements (glass-FRP-NSTC) employing two various methodologies; mathematical modeling and artificial neural networks (ANNs). The dataset of 288 glass-FRP-NSTC compression elements was constructed from the various testing investigations available in the literature. Diverse equations for CS of glass-FRP-NSTC compression elements suggested in the previous research studies were evaluated employing the constructed dataset to examine their correctness. A new mathematical equation for the CS of glass-FRP-NSTC compression elements was put forwarded employing the procedures of curve-fitting and general regression in MATLAB. The newly suggested ANN equation was calibrated for various hidden layers and neurons to secure the optimized estimates. The suggested equations reported a good correlation among themselves and presented precise estimates compared with the estimates of the equations available in the literature with R²= 0.769, and R² =0.9702 for the mathematical and ANN equations, respectively. The statistical comparison of diverse factors for the estimates of the projected equations also authenticated their high correctness for apprehending the CS of glass-FRP-NSTC compression elements. A broad parametric examination employing the projected ANN equation was also performed to examine the effect of diverse factors of the glass-FRP-NSTC compression elements.

• Korean Institute of Interior Design Journal
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• v.25 no.1
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• pp.201-212
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• 2016

This study is a literature study aimed to derive the evaluation factors for the survey of housing satisfaction of the physically handicapped. To attain the objective, the present study compared the influential factors of housing satisfaction for normal people and those for the physically handicapped found in the precedent researches, and analyzed them to draw out the evaluation factors for housing satisfaction of the physically handicapped. And then it drew out sub-factors and elements for the housing satisfaction of the physically handicapped. The evaluation factors for housing satisfaction of the physically handicapped are divided mainly into physical, social-psychological and economic factors. First, physical factor consists of 'functionality (usability)', 'safety', 'convenience', 'comfort', 'aesthetics', 'accessibility (mobility)', 'identifiability (recognition)'. Of them, 'functionality (usability)' factor consists of 3 sub-factors and 8 elements. 'Safety' was subdivided into securing safety and public order/crime prevention. and structural safety, and 7 elements were drawn out from 'safety'. 'Convenience' is sub-categorized into convenient usage and simple operation, and 9 elements were derived. 'Comfort' was classified into 2 sub-factors and 9 elements. 'Aesthetics' was classified into 2 sub-factors and elements. 'Accessibility (mobility)' was divided into 2 sub-factors and elements. 'Identifiability (recognition)' was classified into 2 sub-factors and 5 elements. Second, social-psychological factor includes 'sociality' and 'independence' factor. One sub-factor and one element were drawn from each of both factors. Third, 'economic factor' consists of 'economy'. One sub-factor and elements were drawn out from the factor. It is expected that the 10 evaluation factors, their sub-factors and elements that have been derived from this study can be used as the basic data and/or reference in designing residential space for the physically handicapped and making policy for it after verifying them in following studies. The present study finds itself significance in that the findings here can ultimately improve the housing welfare and life quality of the physically handicapped.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3964-3973
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• 2010

The main purpose of this study is the vertical circulation elements(stairs, elevator, ramp) in a Museum. The first is numerically analyzed in the study. And museum of Korea was limited to the case. The result of the study can be summarized as follows. 1. 50% of cases have 3~4 vertical circulation elements.; (1) ~8 elements: 1(3%), (2) 7 elements: 2(5%), (3) 6 elements: 5(13%), (4) 5 elements: 6(16%), (5) 4 elements: 8(21%), (6) 3 elements: 11(29%), (7) 2 elements: 4(11%), (8) 1 element: 1(3%). 2. There was "stairs alone", "elevator + stairs", "elevator + stairs + ramp", "stairs + ramp" in museum of Korea. Cases of "elevator alone", "ramp alone", elevator + ramp", "stairs + elevator + ramp" was not.; (1) stairs alone: 8(21%), (2) elevator + stairs: 21(55%), (3) elevator + stairs + ramp: 8(21%), (4) stairs + ramp: 1(3%).

• Korean Institute of Interior Design Journal
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• v.17 no.6
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• pp.143-151
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• 2008

This paper inquires the elements of emotional design and the current conditions of its application in order to examine the particularities arise when planning emotional interior design for a women's clinic. Research was done by studying plans for elements of emotional interior design while site investigation was done to find out the status of women's clinic lobby. Six women's clinic in Ulsan were chosen as subjects while survey was done based on the studied emotional plan elements. The data evaluation was classified by the installed properties and substituted with image scale using emotional mensuration. The outcome is as follows; First, elements of emotional interior design was composed of elements making up the space's comfort and aesthetic appreciation, and elements stimulating human's five senses leading to psychological treatment. Therefore, the plan for interior design should merge the design elements that stimulate senses and social elements into one unified concept. Second, the composited elements within the plan should strive to stimulate sights by contracts and changes and add symbolic or meaningful elements based on the principles of design. In so doing, the plan should incorporate an aesthetic orderliness and a coherent image. Third, the interior of women's clinics should not only have psychological comfort but also liveliness and ease that suits 20-30 old women. To conclude, Color, form, finishing materials and texture should be selected with a unified style in mind and the plan itself should strive to generate playfulness though harmonious coordination.