• Korean Journal of Construction Engineering and Management
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• v.5 no.5 s.21
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• pp.101-108
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• 2004

A construction process consists of value adding activities and non-value adding activities, necessary or unnecessary. If construction personnel can eliminate inefficient and/or unnecessary activities within the process, they may have a great opportunity to improve their construction process. The Product Process Analysis (PPA) technique, which was developed in the manufacturing industry, can be applied for identifying wastes in the construction process and ultimately improving the process itself. It provides useful tools, such as a process chart worksheet and flow diagram, for mapping the flow of construction activities with predetermined standardized symbols. These tools make people understand the flow of activities more easily, identify value adding/non-value adding activities within the process, and areas where the process can be improved. The example applications of PPA are demonstrated in the paper through the case studies implemented on the construction process of structural steel. The results of case studies indicate that PPA technique was effective at identifying and removing wastes in the steel construction process. It is also found that PPA technique is more effective for improving highly repetitive construction processes.

• Journal of the Korean Applied Science and Technology
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• v.17 no.3
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• pp.167-173
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• 2000

The process variables for the manufacture of translucent microemulsion prepared with 2-octyl dodecanol, 12-hydroxy stearic acid cholesteryl , POE(40)HCO and 1,3-butandiol were examined initially (primary emulsion) and following aging for three months. The techniques empolyed in this study were particle size, turbidity, interfacial tension and microfluidizer. Particle size analysis and turbidity measurement to evaluate the emulsion stability were used. It was concluded that the process of the emulsification was an important indicator of the stability of the translucent microemulsion. From the particle size and and turbidity measurement of translucent microemulsion, adding the surfactant to the oil phase before the emulsification was found to be the most important factor for the stability of emulsions. We found that interfacial tension of the adding the surfactant to the oil phase is lower than that of the adding the surfactant to aqueous phase. In spite of hydrophilic surfactant, adding the surfactant to aqueous phase produced inferior emulsion to that to oil phase.

• Fashion & Textile Research Journal
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• v.10 no.6
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• pp.822-826
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• 2008

The data for application of mordanting is shown in this experiment by researching dying properties of iron-dye process and concentration changes using persimmon. The strength of persimmon-dying fabrics was controlled by diluting persimmon dye with water and iron mordanting showed the possibility of textile design. The experiments were performed with various conditions processed with iron mordanting liquid by adding water to persimmon-dying liquid and drying well. The most dark color of fabric is observed with the pure persimmon dying without adding water. As the adding water is increased, the color of the fabric is getting lighter with the amount of adding water. After process of iron mordanting, dark color of the fabric turns into dark grey and light color turns into light grey. The possibility of persimmon dying with fabric can be applied in the design of textile with deepened color.

• Journal of the Korean Ceramic Society
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• v.21 no.2
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• pp.143-148
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• 1984

In this study we mainly dealt with the effects of organic retarder(calcium lignosulfate) on the early hydration process of clinker minerals. From a consideration of the hydration process of tricalcium silicate $(C_3S)$ tricalcium silicate $(C_3S)$-tricalcium aluminate $(C_3A)$ tricalcium silicate $(C_3S)$-tetracalcium aluminof-errite $(C_4AF)$ systems with calcium lignosulfate the following results were obtained. 1. when 0.25wt% of CLS was added to $C_3S$ the hydration process was progressed normally but adding of 0.5wt% its hydration was greatly retarded. 2. The hydration of $C_3S$-$C_3A$ system was progressed normally up to 0.5wt% but by adding gypsum its hydration was retarded slightly. 3. The hydration of $C_3S$-$C_4AF$ system was greatly retarded even with 0.25wt% of CLS but by adding gypsum its hydration process was recovered normally.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.416-421
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• 2001

The domestic reinforcement concrete works have mainly worked the process of re-bar fabrication/assembly on site and re-bar works affected by structural safety, durability, and schedule with form work. Accordingly, This study analyzes the process of re-bar fabrication/assembly on site to apply lean production principles to construction Value Stream Analysis(VSA) is analyzed into value-adding activity and non-value-adding activity on construction process through value analysis and Value Stream Mapping(VSM). In the results, non-value-adding activity generates waste such as the activity steps, labors, equipments, materials, time, and so on. Additionally, push-driven production is investigated making low productivity from the overproduction and so on. To resolve the problems in the process, The purpose of this paper eliminates waste factor through maximizing the value-adding activity generating value added and minimizing non-value adding activity. Particularly, it makes flow production and pull-driven production through minimizing work-in-process(WIP ).

• Journal of environmental and Sanitary engineering
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• v.13 no.2
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• pp.95-105
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• 1998

This research was investigated which denitrification of wastewater containing nitrate, using upflow anaerobic sludge blanket process. The upflow anaerobic sludge blanket process is also used for both artifical and industrial wastewater. Main ingredients investigated in the artifical and industrial wastewater experiment were the determination of optimum organism/nitrate ratios, nitrate removal efficiency by various hydrogen donor addition and characteristics of granular sludge and gas production in case of various hydrogen donor addition. From the experimental results the following conclusions were made: In case of adding methanol, ethanol and sodium acetate as hydrogen donor granular sludge was formed 50 days after seeding. Average diameter of granular sludge was 4.0 mm and settling velocity was 37 cm/min. Production rate of gas 3.3 L/d in case of adding methanol as hydrogen donor in wastewater containing 150mg/L nitrate. However adding ethanol and sodium acetate as hydrogen donor, gas production rate were 2.2-2.7L/d respectively. In case of adding methanol as hydrogen donor treatability of artifical wastewater contained 150mg/L as nitrate was about 93%. But in addition of sodium acetate in wastewater contained 40mg.L as nitrate, nitrate removal efficiency was 80%.

• Korean Journal of Construction Engineering and Management
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• v.3 no.4 s.12
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• pp.93-103
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• 2002

The reinforcement concrete work is the work affected by structural safety, durability, and schedule with form work. The domestic reinforcement concrete works have mainly worked the process of re-barfabrication/assembly on site. Finally it have low productivity. Then this paper analyzed waste factors and the process of re-bar fabrication/assembly on site for the productivity improvement and value-added productivity improvement. Waste factor analysis aims at maximizing value-added by the value analysis of re-bar fabrication and assembly on site. Finally, Value-AddingActivity(VAA)ismuchlessthan non-value adding activity. Especially, Non-Value-Adding Activity(NVAA) generates waste such as the activity steps, labors, equipments, materials, time, and soon. And it was non-flow production, over production, and analyzed into having to shift value. This paper aimsat maximizing value-addingactivity and minimizingnon value-addingactivity through waste factor analysis in process for the improvement of value added productivity.

• Journal of the Korean Ceramic Society
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• v.32 no.6
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• pp.719-725
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• 1995

ZST powders were synthesized by coprecipitation of (Zr4+, Ti4+)-hydroxide in the presence of SnO2 particles. Zn(NO3)2 was used as a sintering additive, and according to the adding sequence, sintering and dielectric properties were investigated. Sintered densities of ZST prepared by adding Zn(NO3)2 before calcination were a little higher than those added after calcination, and dielectric properties of the specimen added by Zn(NO3)2 after calcination were better (sintered at 125$0^{\circ}C$/2 h ; Q$\times$f(GHz)=49, 000, $\varepsilon$r=41) than before calcination (Q$\times$f(GHz)=42, 000, $\varepsilon$r=39.5). Through the observation of TEM, it was identified that the cause was due to the difference of the degree of Zn2+ diffusion into grains. With increasing sintering time from 2 to 8 hrs, grain size was doubled and dielectric properties were somewhat deteriorated.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.3
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• pp.373-378
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• 2008

The pH & alkalinity adjustment method by lime and carbon dioxide($CO_2$) for corrosion control in water distribution system was investigated to determine the optimum operational condition in lime adding process in water treatment plant(WTP). The mixing time at dissolution tank and sedimentation time at saturator for maintaining optimal turbidity condition of lime supernatant were 60~75 minutes and 75~95 minutes, respectively. There was no difference according to $CO_2$ adding methods such as $CO_2$ saturated water or $CO_2$ gas. But, $CO_2$ saturated water could be convenience at WTP in terms of pH control and quantitative dosing. To minimize generation of calcium carbonate products, the short time interval between adding of lime and $CO_2$ is most important. The lime should be added below 32 mg/l for preventing pH rising and generation of calcium carbonate products at the heating condition.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.6
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• pp.465-470
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• 2003

The chemical mechanical polishing (CMP) process has been widely used for the global planarization of multi-layer structures in semiconductor manufacturing. The CMP process can be optimized by several parameters such as equipment, consumables (pad, backing film and slurry), process variables and post-CMP cleaning. However, the COO(cost of ownership) is very high, because of high consumable cost. Especially, among the consumables, the slurry dominates more than 40 %. In this paper, we have studied the CMP characteristics of diluted silica slurry by adding of raw alumina abrasives and annealed alumina abrasives. As an experimental result, we obtained the comparable slurry characteristics compared with original silica slurry in the view-point of high removal rate and low non-uniformity. Therefore, we can reduce the cost of consumables(COC) of CMP process for ULSI applications.