• 접착 및 계면
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• 제4권3호
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• pp.9-13
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• 2003

본 연구에서는 점착제의 유지력 개선과 pH 조절을 위해 각각 첨가해 주는 가교제와 pH 조절제의 종류 및 첨가량이 수용성 아크릴 점착제의 점착 물성 및 수용성에 미치는 효과를 알아보기 위하여 중합된 점착 시료에 여러 가지의 가교제와 pH 조절를 첨가해 준 후 초기점착력, 유지력 및 점착력 등의 점착 물성과 수용성을 측정하였다. 가교제를 0.2 wt% 미만 첨가해 주었을 때, 초기 점착력은 감소하였고 유지력과 점착력은 증가하였다. 그러나 0.2 wt% 이상 첨가해 주었을 때는 초기 점착력은 증가하였지만 유지력과 점착력은 감소하는 결과를 보였다. 또한 pH 조절제를 첨가해 주었을 때 pH 조절제의 농도가 증가함에 따라 초기점착력과 수용성은 감소하였고 점착력과 유지력은 증가하였으며, LiOH, KOH, NaOH 순으로 점착 물성과 수용성에 미치는 영향이 큰 것으로 나타났다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.413-416
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• 2005

The super early hardening cement is widely used for reducing construction period. But there are some problems with handling the cement because the loss of workability is so big to control. In this study, the fluidity properties of super early hardening cement paste was evaluated at early age of hydration by using gel-time determination method. 4 types of set controlling agent were selected and combinations of them were used for gel-time test. As a result, the gel-time of super early hardening cement paste was extended up to 20 minutes by using the combinations of several types set controlling agent.

• Journal of the Korean Data and Information Science Society
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• 제23권4호
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• pp.859-866
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• 2012

Some switching properties of multivariate control charts are investigated when the interval between two consecutive sample selections is not fixed but changes according to the result of the previous sample observation. Many articles showed that the performances of variable sampling interval control charts are more efficient than those of fixed sampling interval control charts in terms of average run length (ARL) and average time to signal (ATS). Unfortunately, the ARL and the ATS do not provide any information on how frequent a switch is being made. We evaluate several switching properties of two sampling interval Shewhart and CUSUM procedures for controlling mean vector of correlated quality variables.

• 가정과삶의질연구
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• 제7권1호
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• pp.1-14
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• 1989

The purpose of this study was to identify the problems in the consumption life of household over the family life cycle so that they would support to select the consumer education subjects and the establish the long-term household plan. For these purposes, a survey was conducted using questionnaire. The data used in this study included 562 homemakers living in Seoul. Statistics used for data analysis were frequency distribution, Mean, Percentile, One-way Anova, Scheffie-test, Multiple Classification Analysis. Major findings were as follows; 1) In the level of the problems in the consumption life of household, housing problem, durable goods problem, healthy-medical problem and child education problem area were in the low level. Leisure problem and properties management problem area were in the high level. 2) The problems in the consumption life of household differed significantly over the family life cycle. 3) When controlling family monthly income and education level of husband was compared with not-controlling them, the influences of family life cycle on the problems in the consumption life were as follows. (1)At housing problem area, the effect of the FLC was higher in controlling them than not-controlling them. (2) At other problems the effects of the FLC was lower or same in controlling them than not-controlling them.

• 한국표면공학회지
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• 제57권4호
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• pp.306-316
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• 2024

We conducted experiments to control the hydrophilic/hydrophobic properties by adjusting line and grid patterns on the surface of medical bone fixation plates using a femtosecond laser. Basic experiments were conducted using pure titanium and titanium alloy (6% alumina, 4% vanadium). The spacing of the line and grid patterns was adjusted, and surface properties were confirmed using contact angle measurement equipment. We demonstrated the feasibility of controlling hydrophilic/hydrophobic properties through the patterns of lines and grids. Based on the results of the basic experiments, surface treatment was applied to medical bone fixation plates currently used in clinical practice. Through laser processing, we confirmed a contact angle of approximately 9.18° for hydrophilicity and approximately 101.07° for hydrophobicity. We confirmed that easy control of hydrophilic/hydrophobic properties is achievable using laser processing technology and anticipate its application in various medical component fields.

• 한국세라믹학회지
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• 제48권5호
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• pp.404-411
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• 2011

The humidity controlling ceramic materials was developed by applying the phenomena of dew condensation in the capillary. It is said that the humidity range which human feels comfortable is from 40 to 70% in relative humidity. In this study, the ceramic tile using natural soils such as diatomite for interior wall was investigated. In particular, we had introduced novel processing routes for fabricating microcellular ceramics tile using hollow microsphere as a pore former. The microcellular pores in the humidity controlling ceramic materials showed the superior properties such as light-weight, heat insulation. The cell density was ${\sim}1.0{\times}10^9$ cells/$cm^3$ and density of sample was 0.65 g/$cm^3$ in the case of 1.71 wt% hollow microsphere content. Also, it is observed that the BET surface area and the pore volume of the sintered diatomite tile have the values of 40.92 $m^2$/g and 0.173 $cm^3$/g.

• 대한수학회지
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• 제35권3호
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• pp.727-740
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• 1998

Controlling traffic lights at a bottleneck, in [5] a time of open passage is called optimal, if it minimizes the first moment of the asymptotic distribution of the queue length. The discussion of the first moment as function of the time of open passage is based on an analysis of the behavior of a fixed point when varying control parameters and delivers theoretical and computational aspects of the traffic problem.

• Journal of the Korean Wood Science and Technology
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• 제25권4호
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• pp.10-16
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• 1997

This study was carried out to improve coating structure by controlling the electrostatic interaction of coating components and by changing the coating structure of coated paper prepared with amphoteric and anionic latices. The results indicated that amphoteric latex copolymerized with carboxylic and amine groups had stronger interaction with other coating components than anionic latex with branched carboxylic group by controlling pH. These properties of amphoteric latex showed positive effects on viscosity rheology, and supernatant sediment of coating color. The coated paper using amphoteric latex had also produced more porous and smoother coverage of the coating layer than that using anionic latex. This porous and smooth coating layer showed better optical properties and printability than those of anionic latex such as opacity, porosity, ink set-off, and wet ink receptivity.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.818-821
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• 2003

Sn-doped $In_{2}O_{3}$ (ITO) thin film is one of the materials widely on research not only in the academic fields but also in industrial fields because of their transparency, high conductivity and good adhesion characteristics on substrate. ITO thin films are usually preferred oriented to one of the (222), (400), and (440) planes during crystallization process, which is dependent on processing variables. The preferred orientation affects electrical, optical and etching properties of the films. In this study, thin films of preferred oriented in different orientation were fabricated by controlling processing variables. The crystallization behavior, grain size, surface roughness, transparency and electrical properties of the thin films in different orientation were examined.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2016년도 추계학술대회 논문집
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• pp.118.1-118.1
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• 2016

The laser surface modification has been reported for its functional applications for improving tribological performance, wear resistance, hardness, and corrosion property. In most of these applications, continuous wave lasers and pulsed lasers were used for surface melting, cladding, alloying. Since flexibility in processing, refinement of microstructure and controlling the surface properties, technology utilizing lasers has been used in a number of fields. Especially, femtosecond laser has great benefits compared with other lasers because its pulsed width is much shorter than characteristic time of thermal diffusion, which leads to diminish heat affected zone. Moreover, laser surface engineering has been highlighted as an effective tool for micro/nano structuring of materials in the bio application field. In this study, we applied femtosecond and nanosecond pulsed laser to treat biometals, such as Mg, Mg alloy, and NiTi alloy, by heating to improve corrosion properties and functionalize their surface controlling cell response as implantable biomedical devices.