• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
• /
• pp.671-674
• /
• 2005

In this study, it is examined the properties of early strength of concrete mixed with polycarboxylate superplasticizer. For this experiment, it is analyzed that the slump and strength properties according to the mixture factors, compared with cements and superplasticizers of each company and curing temperature($15,\;20^{\circ}C$). (1) The slump loss of concrete used polycarboxylate superplasticizer(rapid strength type) showed $0.5\~1.5cm$, it is judged that slump loss according to the time lapse can be minimized. (2) The performance of polycarboxylate superplasticizer kept up consistency and accelerated strength development. it is possible to reveal 12MPa within $18\~20$hours at $20^{\circ}C$ curing, but impossible within 24hours at $15^{\circ}C$. (3) It is necessary to studies about rapid strength development in the low temperature.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2006년도 춘계 학술발표회 논문집
• /
• pp.1155-1158
• /
• 2006

This paper presents a study on the construction condition and environmental effect of deep soil mixing. Construction condition means the difference in unconfined compressive strength with respect to the depth and location of samples. Environmental effect means alkalinity diffused from soil stabilizer. The experimental results indicate that the unconfined compressive strength vary with respect to the depth, and doesn't show consistency pattern. So, in field application we must decide a mixing ratio enough to satisfy the least unconfined compressive strength. The difference in unconfined compressive strength with respect to the location of samples is negligible. The generation of alkalinity from soil stabilizer is reduced by permeating in non-improved soil and it is expected that the diffusion of alkalinity has no environmental effect on soil and ground water.

• Geomechanics and Engineering
• /
• 제20권6호
• /
• pp.505-516
• /
• 2020

In recent years, Nano-technology significantly invaded the field of Geotechnical engineering, particularly in soil stabilisation techniques. Stabilisation of weak soil is envisioned to modify various soil characteristics by the addition of natural or synthetic materials into the virgin soil. In the present study, laboratory experiments were executed to investigate the influence of nano-silica particles in the consistency limits, compressive strength of the soft clay blended with cement. The results revealed that the high compressibility behaviour of soft clay modified to medium-stiff condition with fewer dosages of cement and nano-silica. The mechanism behind the strength development is verified with the previous researches as well as from Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction test (XRD) and Scanning Electron Microscopy (SEM) analysis. Based on the results, the presence of nano-silica in soft clay blended with cement has a positive effect on the behaviour of soil. This technique proves to be very economical and less detrimental to the environment.

• Journal of Mechanical Science and Technology
• /
• 제19권5호
• /
• pp.1131-1137
• /
• 2005

Methods for measuring surface roughness based on light reflectivity have advantages over methods based on light interference or diffraction, especially in in-situ, on-the-machine and in-process applications. However, measurement inconsistencies caused by changes in the specimen are still a drawback for field applications. In this study, we propose a new feedback-based algorithm to enhance the consistency against changes in the specimen. The algorithm is deduced from simulations based on light reflectance theory with typical modeled surfaces. The proposed method is similar to a digital controller and regulates the power of reflected light. Experiments varying heights and materials, verified the improvements in robustness of the method against measurement disturbances caused by specimen changes.

• Advances in Energy Research
• /
• 제3권1호
• /
• pp.59-70
• /
• 2015

In India, continuous production of electricity and sweet/potable water from Solar power and desalination plant plays a major role in the industries. Particularly in Copper industry, Solar power adopts Solar field collector combined with thermal storage system and steam Boiler, Turbine & Generator (BTG) for electricity production and desalination plant adopts Reverse osmosis (RO) for sweet/potable water production which cannot be used for long hours of power generation and consistency of energy supply for industrial processes and power generation cannot be ensured. This paper presents an overview of enhanced technology for Solar power and Desalination plant for Copper industry making it continuous production of electricity and sweet/potable water. The conventional technology can be replaced with this proposed technique in the existing and upcoming industries.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2013년도 춘계 학술논문 발표대회
• /
• pp.232-233
• /
• 2013

The unit-water content in fresh concrete determines consistency, and play an important role in condensing the structure of concrete and enhancing the durability of concrete. The capacitance measurement method measure quickly unit-water content and is the best way to apply to construction site. In this study, the unit-water content of capacitance measurement method is estimated according to types and replacemment ratio of admixture. and the field application of capacitance measurement method is reviewed.

• Journal of Mechanical Science and Technology
• /
• 제20권8호
• /
• pp.1169-1182
• /
• 2006

Robust design technology has been applied to versatile engineering problems to ensure consistency in product performance. Since 1980s, the concept of robust design has been introduced to numerical optimization field, which is called the robust optimization. The robustness in the robust optimization is determined by a measure of insensitiveness with respect to the variation of a response. However, there are significant difficulties associated with the calculation of variations represented as its mean and variance. To overcome the current limitation, this research presents an implementation of the approximate statistical moment method based on kriging metamodel. Two sampling methods are simultaneously utilized to obtain the sequential surrogate model of a response. The statistics such as mean and variance are obtained based on the reliable kriging model and the second-order statistical approximation method. Then, the simulated annealing algorithm of global optimization methods is adopted to find the global robust optimum. The mathematical problem and the two-bar design problem are investigated to show the validity of the proposed method.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
• /
• pp.93-94
• /
• 2006

The $I_c$ degradation behavior of YBCO CC tapes due to torsional deformation has been investigated. Particularly, the influence of torsion angle on the $I_c$ in HTS tapes was examined at 77K (self-field). At low torsional angles or shear strains, the $I_c$ degradation was small and gradual. Also, a good consistency of the $I_c$ degradation behaviors was found along the longitudinal direction under torsion when multiple voltage terminals were adopted for investigating the homogeneity of the $I_c$ degradation.

• 한국정밀공학회지
• /
• 제25권6호
• /
• pp.150-158
• /
• 2008

This research considered that the significance of the NT(Nano Technology) which gradually increased the importance of it and investigated the technology development current situation of the Korea, U.S.A, Japanese, Europe. Therefore, in domestic and foreign, this research was widely used. It includes the tendency of the technology about processing methods using the ion beam and electron beam among the In-line system related technique field for the high efficiency energy beam application nano scale manufacturing components. The technique level of Korea, the international trend of technology and cooperation research present condition are dealt in. The information about the checked out of business of research and development of the country consistency and policy establishment try to be provided.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2004년도 추계학술대회논문집
• /
• pp.513-516
• /
• 2004

Consistency in design, manufacture, installation and performance test of expansion joints is insufficient for guarantee of reliability because they are imported from various foreign countries as America, Japan and Europe. In addition to that, the regulations or codes of expansion joint should be revised and established for levels of vibration and noise generated from riding vehicles especially. Regulation on the noise neighboring traffic roads is established by ministry of environment. Therefore, Field tests on the vibration and the noise at expansion Joints, especially rail-type and finger-type joints which are typical ones in bridge with short or middle span, are performed and performance of expansion joints are analyzed. And so, the results of the investigation will be utilized as basic data for the regulation on the vibration and the noise.