• Land and Housing Review
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• v.4 no.2
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• pp.193-200
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• 2013

Construction duration in construction project is an important factor which affects project cost. Advanced countries have reduced project cost by time shortening. Even though domestic construction companies have tried to time shortening, they yet failed to find systematic method for time shortening. Typically, duration of structural framework is affected by stripping time of form. Therefore, it need to shorten the stripping time of form for time shortening of structural framework. In this study, specimens of high-early-strength concrete were manufactured with variety conditions and compressive strength was tested. This study proposed stripping time of side and slab forms using test results. The stripping time of form was shortened when using high-early-strength concrete in structural framework by the test results. The result of this study will be useful for time shortening of structural framework.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.203-204
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• 2014

Unlike other members, beams have various cross-sections and they have an important role of delivering the load of slabs. A beam form neighbors the columns and slabs, which makes it difficult to be installed. In a conventional way to exclusively use the form after concrete pouring, the form and a support should be both removed. Then, the support should reinstalled to sustain the stripping time of form, resulting in a structural issue. To solve such structural problem, the study proposes SMART beam form that uses filler panels and supports for filler. The floor filler panels and supports for filler are not removed after concrete curing, to conform to the stripping time of supports. Thus, any structural problem such as cracks and reduction of compressive strength owing to the gap of load bearing capacity can be prevented. The study results will be used as cases for studies on productivity analyses.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.1219-1224
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• 2001

In this study, concrete what plenty of fly ash used as binder is left in three condition humid condition($35^{\circ}C$), normal condition($20^{\circ}C$) and cold condition($5^{\circ}C$). Fly ash concrete is tested in fresh properties and early strength. The result of tests could give the decisive factor of form side's stripping time. The purpose of this study is presenting the stripping time data to help the construction work. The result of this study is below. 1. The plain concrete specimen in humid condition developed high strength before 5 days, then strength development is declined. 10 day strength of plain specimen is smaller than the normal condition specimen's. 2. The strength of the concrete which plenty of fly ash used is more developed than the concrete in normal condition. It says that fly ash concrete is useful in the humid condition. 3. As fly ash substitution rate is downsizing and outdoor temperature degree is low, form stripping times is getting shorter.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.3
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• pp.475-480
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• 1992

The effect of mechanical factors and season of the year on milking characteristics (milk yield, time of milking, rate of milk flow, stripping time and tripping milk) were studied on 26 Holstein Friesian cows, raised under Saudi Arabia environmental conditions. Cows were in the third and fourth lactation and reached the peak. Cows milked twice a day with equal intervals. Three vacuum levels (34, 38 and 42 cfm) and two pulsation ratios were used to form six vacuum-pulsation combinations. The study was carried during two seasons Autumn-Winter (S1) and Spring-Summer (S2). After absorbing the cow equations least square analysis was used to analyze the data. Vacuum level 38 cfm and pulsation ratio 70:30 was the best among all combinations of vacuum level-pulsation ratio. No significant effect (p < .01) for season, up to the seventh half minute, on the rate of milk flow. However, season of the year has a significant effect on total milk yield, stripping time and stripping milk.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.1
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• pp.119-125
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• 1999

Conventional interproximal stripping using abrasive strips is normally limited to the anterior teeth. The strips must be forced between the contact points of the teeth creating patient discomfort and the risk of cutting gingival tissue. Air-rotor stripping(ARS) with Essix anterior anchor enables the clinician to remove a precise amount of interproximal enamel to create space, primarily in the buccal quadrants, for aligning or retracting teeth. In selected cases, ARS can resolve significant differences in ratios of tooth site to arch length, and the technique can become an alternative to extraction or expansion. ARS can create substantially more space than that is usually obtained by conventional interproximal stripping, and it can be done at any time during treatment without discomfort to the patient and without adversely affecting the function of the dentition, interocclusal relations, or tooth form.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.2
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• pp.59-66
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• 2008

In the construction site, to improve the man-dependent form work, non-stripping form has been studied but the developed non-stripping form was hard to applied with respect to the cost, form size and performance. This study is for evaluating the adaptability of the developed non-stripping form named as high performance permanent form (HPPF). To do this, the analytical approach and parametric study were performed based on the research for fundamental material characteristic of the HPPF. The target concrete structure is a wall structure because of its effectiveness of HPPF. To evaluate the structural efficiency of the HPPF applied wall structure, FEM analysis was performed to decide the maximum placing height at one time then it was applied to design the wall structure. In the result of the analysis, the HPPF applied wall structure showed the lots of advantages that it can reduce the cost resulted from reducing concrete and steel rebar even if it has same structural performance to the conventional concrete wall structure with same dimension. With this analysis result, it can be evaluated that the HPPF applied concrete structure can be a concrete structure with the long term durability in site.

• Journal of the Korea Institute of Building Construction
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• v.3 no.1
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• pp.115-122
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• 2003

In order to analyze liquidity change according to increasing the charge of superplasticizer, we inputted charges by dividing into six steps, 0% through 1.25%; at the same time, to observe liquidity change according to the change of charge-time, we carried out the experiment applying 30-minute intervals, i.e. at beginning of mixing, 30, 60 and 90 minutes. The results are below. 1) According to increasing the charge of superplasticizer, the liquidity of concrete was enhanced, however, when inputted 1.25%, a little segregation was occurred, which allowed us to make a conclusion that concrete performance would be deteriorated due to this segregation. 2) When we inputted 1.25% of superplsticizer, steady liquidity features were shown regardless of the charge-time of concrete, which allowed us to make a conclusion that this input would be the best for liquidity performance considering only liquidity features. 3) After analyzing the dynamical features of liquid concrete, the result showed that there was not significant effect on revelation of compressive strength. We concluded form this result that there was no influence on the stripping-time of a mold form. 4) When we charge superplasticizer in concrete more than 1%, we, in advance, should clearly judge the concrete performance required during constructing in site, as it were, the compressive strength or liquidity etc.; furthermore, we had better decide a charge and input-time of superplasticizer to meet the required performance.

• Journal of the Korea Concrete Institute
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• v.16 no.3 s.81
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• pp.327-334
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• 2004

In this paper, method for the determination of removal time of the side forms in high strength concrete are discussed using the estimation model of compressive strength development, the development of bond strength and rebound number of P type Schmidt hammer in order to review the validity of existing regulation as to side form removal and offer effective quality control method. According to the results, as W/B increases by $10\%$, the setting time is shortened by about 2 hours. In the scope of the paper, required time to gain 8MPa of compressive strength is determined about 17 ${\~}$20 hours of age and $21{\~}25^{\circ}D{\cdot}D$ of maturity. Bond strength between form and concrete shows the highest value around final setting time, but decreases drastically after that. Amount of concrete sticking on the form is large before setting completed, but after that, its amount shows decline tendency. The rebound value test with P type schmidt hammer can be started faster by 2${\~}$3 hours than compressive strength test. It is also confirmed that the removal of forms is possible when the rebound value of P type schmidt hammer is more than 32. It is found from the results that existing regulation regarding removal time of the side form of high strength concrete provided in KCI needs no revision because required time to gain the strength provided in KCI has no adverse effect on strength development at early age and surface condition during stripping the side form. Effective procedure to decide the removal time of side form can be performed by applying P type Schmidt hammer.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.560-563
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• 2004

This study reports the site application of concrete using AE Water Reducing Agent of Early-Strength Type. According to the lab test results, we have made plans of batch plant pilot test, and we have analyzed the erly aged compressive strength and workability of the concrete. We applied the early-strength development concrete to the construction site. We accomplished the slump test in order to evaluate the workablity and air contents, we made site curing mold to evaluate the early strength of members. As a result, we judgeed the superior property of early strength development of the concrete, and thought that we can reduce the time of form stripping more $40\%$ than ordinary strength concrete. We thought that we can reduce the term of works and finally we can accomplish the economical construction.

• Journal of The Korean Astronomical Society
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• v.37 no.5
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• pp.575-578
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• 2004

High resolution observations of cluster of galaxies by Chandra have revealed the existence of an X-ray emitting comet-like galaxy C153 in the core of cluster of galaxies A2125. The galaxy C153 moving fast in the cluster core has a distinct X-ray tail on one side, obviously due to ram pressure stripping, since the galaxy C153 crossed the central region of A2125. The X-ray emitting plasma in the tail is substantially cooler than the ambient plasma. We present results of two-dimensional magnetohydrodynamic simulations of the time evolution of a sub clump like C153 moving in magnetized intergalactic matter. Anisotropic heat conduction is included. We found that the magnetic fields are essential for the existence of the cool X-ray tail, because in non-magnetized plasma the cooler sub clump tail is heated up by isotropic heat conduction from the hot ambient plasma and does not form such a comet-like tail.