• KIEAE Journal
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• v.15 no.2
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• pp.61-67
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• 2015

Purpose: The balcony in the apartment is important space not only as a fire escape but also as a buffer for heat and sound insulation. However, with the legalization of balcony expansion for residential apartments in Korea in 2006, many households have eliminated the balcony space altogether to increase the inner space, often without sufficient consideration for the effects on the indoor environment. This study examined the sound insulation performance of exterior-facing windows in enclosed balconies and the changes in the indoor acoustic environment due to expansion to provide a basis for appropriate balcony expansion. The apartments for the field test were chosen where two balcony types can be compared, and the sound insulation performance for the eighteen balcony windows was measured. The windows installed were typical double window with thickness 16 mm or 22 mm. Measurements of the weighted standard sound pressure level difference showed a decrease of about 3 dB in sound insulation performance due to expansion. For common exterior noise levels of 70-85 dB(A), the indoor noise level can exceed 45 dB(A), the limit level regulated in Korea. However, it was found that the sound insulation performance of the window and the quality of the construction have more influence on indoor noise levels than balcony expansion itself.

• Korean Journal of Human Ecology
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• v.18 no.3
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• pp.729-740
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• 2009

This study is to research on the rate of expansion or contraction according to movement of the lower body of the man their twenties using Rapid Form software. And aim of this study is to get information of ease allowance in developing slacks pattern using 3D body surface scan data through comparison with existing slacks patterns. Considering on the contraction and expansion according to movement, it need to set the more ease allowance in hip circumference than waist circumference, and the more ease allowance in back hip width than front hip width in slacks. In crotch length, the length of front crotch is revealed contraction but the length of back crotch is revealed expansion. It is desirable lowering front waist line and raising back waist line to possess ease allowance in back crotch area. The length of side seam is revealed a little expansion but the length of inseam is showed a great expansion. To develop slacks pattern of scientific approach using 3D body surface scan data, it need to analysis the rate of expansion and contraction of the lower body based on the movement, shear deformation, slip in fabrics and skin, or in fabrics and fabrics, and slip down from waist line.

• Journal of the Korean Ceramic Society
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• v.46 no.5
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• pp.493-496
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• 2009

Phase stabilized leucite, which has high coefficient of thermal expansion, was synthesized, and its thermal expansion behavior was investigated. The homogeneous leucite phase was synthesized by solid state reaction from the mixture of $K_2CO_3-Al_2O_3-SiO_2$. and its stabilization from tetragonal to cubic phase was attempted by adding $Cs_2CO_3$ into starting materials. And fine powder with an average particle size of a few hundreds ${\mu}m$ were fabricated by planetary milling. During milling, amorphization of leucite was observed and recrystallized after heat treatment. The thermal expansion behavior of tetragonal and cubic leucite has measured and discussed. The average coefficient of thermal expansion of tetragonal and cubic phase leucite from room temperature to $750^{\circ}C$ was $21.4{\times}10^{-6}/^{\circ}C$ and $14.5{\times}10^{-6}/^{\circ}C$, respectively.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.77-77
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• 2003

Coculture of HSC with bone marrow-derived mesenchymal stem cells (BM-MSCs) is one of used methods to increase cell numbers before transplant to the patients. However, because of difficulties to purify HSCs after coculture with BM-MSCs, it needs to develop a method to overcome the problem. In the present study, we have examined whether a culture insert placed over a feeder layer might support the expansion of HSCs within the insert. $CD34^+/ $ cells isolated from the umbilical cord blood by using midiMACS were divided into three groups. A group of 1 $\times$ $10^5$ cells were grown on a culture insert without feeder layer (Direct). The same number of HSCs was directly cocultured with BM-MSCs (Contact). The third group was placed onto an insert below which BM-MSCs were grown (Insert). To distinguish feeder cells from HSCs, BM-MSCs was pre-labeled fluorescently with PKH26 and 1 $\times$ $10^5$ cells were seeded in the culture dishes. After culture for 13 days, the expansion factor (x) of HSCs that were grown without feeder layer (Direct) was $26.6 \pm 8.4.$ In contrast, the number of HSCs directly cocultured with feeder layer was 59.6 $\pm$ 0.5 and that of HSCs cultured onto an insert was $46.9 \pm 8.4.$ The percentage of BM-MSCs cells remained being fluorescent was $97.9 \pm 0.3%$ after culture. Immune-phenotypically large proportion of cultured cells were founded to be differentiated into myeloid/monocyte progenitor cells. The ability of BM-MSCs, fetal lung, cartilage and brain tissue cells to support ex vivo expansion of HSCs was also examined using the insert. After 11 days of coculture with each of these cells, the expansion factor of HSCs was 15.0, 39.0, 32.0 and 24.0, respectively. Based upon these observations, it is concluded that the coculture method using insert is very effective to support ex vivo expansion of HSCs and to eliminate the contamination of other cells used to coculture wth HSCs.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.535-539
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• 2011

This study was conducted to examine the bootstrap evaluation of the stem density and biomass expansion factor for Pinus rigida plantations in Korea. The stem density ($g/cm^3$) in less than 20 tree years were 0.460 while more than 21 tree years were 0.456 respectively. Biomass expansion factor of less than 20 years and more than 21 years were 2.013, 1.171, respectively. The results of 100 and 500 bootstrap iterations, stem density ($g/cm^3$) in less than 20 years were 0.456~0.462 while more than 21 years were 0.457~0.456 respectively. Biomass expansion factor of less than 20 years and more than 21 years were 1.990~2.039, 1.173~1.170, respectively. The mean differences between observed biomass factor and average parameter estimates showed within 5 percent differences. The split datasets of younger stands and old stands were compared to the results of bootstrap simulations. The stem density in less than 20 years of mean difference were 0.441~1.049% while more than 21years were 0.123~0.206% respectively. Biomass expansion factor in less than 20 years and more than 21 years were -1.102~1.340%, -0.024~0.215% respectively. Younger stand had relatively higher errors compared to the old stand. The results of stem density and biomass expansion factor using the bootstrap simulation method indicated approximately 1.1% and 1.4%, respectively.

• Reproductive and Developmental Biology
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• v.30 no.4
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• pp.287-291
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• 2006

We have developed a new passaging technique for the expansion of human embryonic stem cells (hESCs) that involves simply pipetting portions of hESCs acquired from colonies, reducing the laborious and time-consuming steps in the expansion of hESCs. Compared to general mechanical methods of passaging, our pipetting method allowed hESCs colonies to be broken into small fragments, which showed significantly higher attachment rates onto feeder cell layers. This technique produced three times the number of hESCs colonies than conventional mechanical methods. In addition, this pipetting method allowed us to distinguish differentiated hESCs from undifferentiated hESCs during hESCs colony pipetting. The hESCs cultured by pipetting method displayed normal human chromosomes for over 60 passages. According to RT-PCR and immunohistochemical analysis, the hESCs successfully maintained their undifferentiated state and pluripotency which was also confirmed by teratoma formation in viva Therefore, the pipetting method described in this study is a useful tool to efficiently and quickly expand hESCs on a large scale without enzyme treatment.

• The korean journal of orthodontics
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• v.34 no.1 s.102
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• pp.23-31
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• 2004

As a research method that weighs and combines evidence, meta analysis produces evidence that is more powerful than the original studies. The purpose of this study was to compare the jntercanine/intermolar expansion and rapid/slow expansion in the maxillary expansion treatment using meta analysis. Medline was searched from 1979 to 2000 for all studies examining the stability of transverse expansion of the human maxilla, and 388 articles were found. Then these articles were reduced to 7 based on the defined inclusion and exclusion criteria, and a cumulative Meta evaluation score was computed for each study. The results were as follows; 1. The mean expansion in intermolar width was 6.0mm. of the 6.0mm, 4.8mm was retained and $20.0\%(1.2mm)$ was relapsed while wearing retainers. 2. In intercanines width, the mean expansion was 3.7mm. of the 3.7mm, 2.6mm was retained and $29.7\%(1.1mm)$ was relapsed while wearing retainers. 3. The differences In the amount of expansion and relapse between rapid expansion group and slow expansion group were less than $6\%(0.1-0.3mm)$. But, there might be differences in the skeletal/dental exapnsion ratios according to the expansion method.

• Journal of the Korean Geosynthetics Society
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• v.17 no.1
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• pp.75-83
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• 2018

This paper described a results of dynamic stability by using wheel tracking test and unconfined compression test, in order to evaluate behavior characteristics on the developed pocketable expansion material for emergency restoration of ground cavity. The wheel tracking test result showed that the settlement increment ratio of the recovered ground by the expansion material was decreased compared to the sandy ground in high load condition. That is, it was confirmed that the expansion material was able to restrain the settlement due to the material stiffness, and the same results were obtained for the dynamic stability evaluation results. From the results of unconfined compression test, the pocketable expansion material was found to be able to fully support load on the restored cavity.

• Journal of the Korean Institute of Educational Facilities
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• v.22 no.1
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• pp.25-36
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• 2015

Historically, college campuses have played a role of a city, and the development pattern of various forms and functions of cities was found in the growth stages of campuses as well. In this way, campuses developed in close relationships with our lives and such a characteristic can be confirmed in a number of cases in and out of the country. The strategic concept of such expansion is shown in the strategic classification through a master plan. This research examines concepts of major universities in the metropolitan area of Korea for promoting campus expansion and proposes implications through them. The results drawn from the research are as follows. Firstly, various developmental directions should be sought in aspects of planning, programming and economics for campus expansion with the complex application of such factors. Secondly, the multi-campus strategy of past localization era is changing into the concept of forming a global campus materializing itself as the planning strategy of internal campus. Thirdly, the physical barrier is being dissolved as a way to promote the relationship with local communities, and particularly, the management strategy of constructing new buildings in connection with local communities is the leading measure of materialization. Lastly, the development of underground space is actively carried out due to the limitation of ground physical space through which a role of establishing new campus order along with securing space is pursued.

• The Journal of Engineering Research
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• v.6 no.2
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• pp.141-151
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• 2004

The physical properties of gold investment materials are depending on it's thermal expansion coefficients, compressive strength, and particles size distributions. Normally the gold investment materials are consisted of cristobalite, quartz and plaster. Since the thermal expansion coefficient of cristobalite and quartz are $2.6\times10^{-6}/^\circC$, $2.32\times10^{-6}/^\circC$, respectively, the composition ratio of each components influence the thermal and clinical properties of gold investment materials. Recently are imported from overseas and the commercial market is expected to expand. Thus it is necessary to develop the optimum strength and compressive strength of gold investment materials which the an homogeneous size distribution and thermal expansion coefficients. Therefore two different experiments has been done. Firstly the homogeneous cristobalite and quartz are made by pulverizing milling. Secondly the compressive strength and thermal expansion coefficients are analysed by the composition ratio of cristobalite and quartz. As a results of experiments, homogeneous distribution of cristobalite and quartz are observed by pulverizing and milling. The optimum compressive strength was obtained at the ratio of 45:25 cristobalite, quartz respectively.