• Journal of the Korean Ceramic Society
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• v.11 no.2
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• pp.11-16
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• 1974

Korean Yung-il bentonite was treated with potassium chloride, zinc chloride, calcium chloride, ferric chloride, or chromic chloride solutions respectively varying their concentration, treating temperature and treating time. The adsorbabilities of methylene blue on these pretreated bentonite were investigated. In the case of treatment with potassium chloride solution, the improvement of the adsorbahility of methylene blue on the products was observed, and in the best result the adsorbability was 1.6 times better than that on the original bentonite. With zinc chloride solution, the optimum adsorbability was a value of 1.7 times better than that on the original bentonite. With ferric chloride, chromic chloride or calcium chloride solution, slight improvement of the adsorbability was observed.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.2270-2277
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• 2010

Recently the role of a railroad is emphasized as the imprortant part for growth for the low carbon green growth and the social consensus about the railroad investment is actively progressed. The various social economic value in which the travel demand change over of the environment-friendly railroad system can bring becomes with public debate as much as a discussion is not any more necessary. In this research, the influence that it recognized that the travel time improvement by the high speed rail was the most important element among many method that it can increase the railroad use efficiency in which it connects the interregional major cities and the railway travel time improvement reaches to the rate of railway and road travel time, and the environment like the carbon emission quantity was comprehensively inquired.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.120-121
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• 2017

Generally, slump of plain concrete slab is about 120~150mm and slump loss is easy to occur. So, water is added to concrete because this method is convenient for Placing. In order to solve this problem, performance evaluation of concrete using improvement type PC admixture was carried out. Target slump is 210mm and compressive strength is 18MPa. As a result, slump reference value was satisfied 60 minutes after placing and 7-day compressive strength was 21~25MPa.

• Environmental and Resource Economics Review
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• v.11 no.1
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• pp.1-29
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• 2002

Faced with large scale of outdoor recreation resources and variety of demanders' desire, it would be necessary for the managers to estimate the values of individual attributes rather than a bundle of characteristics of outdoor recreation sites. By extending the Brown and Mendelsohn's (1984) approach we are able to estimate the beneficial effects of the improvement of individual attributes. Sampling 208 fishermen who visited 11 free fishing sites located in Daegu and Gyeongbuk, the functions of marginal willingness to pay for scenery and non-crowdedness were estimated. If 1 unit of scenery could be improved from its average value a fisherman, on average, would receive benefit of as much as 3,840 won. The average beneficial effect of the non-crowdedness improvement would amount to 2,220 won.

• Journal of the Korean Society of Safety
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• v.21 no.1 s.73
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• pp.41-47
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• 2006

This paper introduces stress monitoring system for buried gas pipeline in poor ground. During the six months of improvement construction of poor ground, maximum settlement of gas pipeline is about 40 cm. This value represents relative small compared to the initial settlement estimation of ground improvement construction plan, 90 cm. Also, this paper includes the result of finite element analysis of gas pipeline to confirm safety of pipelines in poor ground. The stress monitoring system for gas pipeline was developed to guarantee the safety of buried gas pipeline in poor ground. Eventually, the ground improvement workings are ended safely and it is proved that the pipeline has no safety problem.

• Journal of the Korean Professional Engineers Association
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• v.30 no.5
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• pp.82-95
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• 1997

A Study of Improvement in Reactor Thermal Power Measurement Method using Kalman Filter. The objectives of the safety analysis of nuclear power plants are to maintain the surface temperature of fuel and fuel cladding within limit value in case of Loss of Coolant accident (LOCA) so that it ensures the safety and reliability of nuclear power plants. The new technique evaluating the reactor power and improvement of existing plant system increase the safety margin of nuclear power plant operation, and accordingly, economic effect will be anticipated. Hereby, 1 would like to introduce reactor power measurement method using Kalman filter that enables to calculate the reactor power more precisely combining the parameters, for example, turbine output as the 1 st stage pressure of high pressure turbine, and reactor power using energy equilibrium relation. It is expected that the new technique will enhance the accuracy of measurement of reactor power and maintain the reliability of nuclear power operation by increasing operational safety margin, and gain the economic benefit

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.562-567
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• 2003

This paper presents the method of Rate of Loading(ROL) improvement for the Motor Operated Gate Valve operating in high differential pressure condition. The character of ROL and Stem Factor is analyzed. Static test and dynamic test were performed and acquired the diagnosis signal for the valve closing stroke. The result of this study is the modification of stem factor is very important factor for the ROL improvement. In order to obtain the same value of dynamic test thread friction coefficient stem and stem nut should be combined appropriately.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.4
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• pp.1-7
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• 2003

In this study, fiber mechanical pretreatment before refining was executed with the addition of papermaking addiditives to find synergistic effects on fiber property improvement. Three fiber furnishes (SwBKP, KOCC, and BCTMP), and five different additives (CMC, CPAM, PEO, NaOH, $Na_2O_2$) were used. It was confirmed again that fiber mechanical pretreatment using Hobart mixer was a special way to modify fiber properties, where fiber WRV (water retention value) increases without losing fiber length. For SwBKP, addition of small amount of CMC (0.2％ OD basis), and for KOCC, PEO (0.2％ OD basis) caused additional significant improvement of the fiber furnish properties, respectively. Other additives did not cause adverse effects on the mechanical pretreatment, or better. For BCTMP, NaOH addition followed by mechanical pretreatment caused more than 20％ improvement in tensile and tear strength simultaneously, compared to the control. The yellowing caused by the treatment of NaOH on BCTMP could be minimized by using $Na_2O_2$ without losing the positive effect of NaOH.

• Journal of the Korea Safety Management & Science
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• v.18 no.4
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• pp.131-137
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• 2016

In unlimited competition era changed rapidly, productivity improvement and raw cost reduction by working improvement are very important for the survival of middle and small-sized companies. At this moment, middle and small-sized companies are cleary important in domestic industry. Therefore, this researcher applied TPS(Toyota production system) 7 wastes by experiment planning method for wastes of lots of working processes at the manufacturing site of automobile assembly manufacturing company, D company, analyzed current system of D company applied so as to verify if value creation works and factors were minimized during the production and drew results by analyzing experimental planning for analyzing waste elimination.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.1D
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• pp.61-69
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• 2012

The purpose of this study is to draw the development direction of subway adjacent area by distance through an analysis on influence factors of land value by urban spatial constitution. The method of this study is analyzing influence factors of land value by the distance of subway adjacent area by using regression analysis method with urban spatial constitution variables from advanced research and drew the difference and extent of land value influence factors by distance of subway adjacent area. The result of analyzed the influence factors of land value by distance to draw the purpose of this study, which is the direction of development by distance of subway adjacent area, the connected area has shown the development direction as high density development centrally on commercial and improvement of accessibility and decrepit status, the directly influence area shows as complexity with high density centrally on commercial and business and lastly, the in directly influence area has shown the development direction as complexity of residential and commercial, improvement of accessibility and decrepit status. This study has used land value as a dependent variable to verify the speculation of this study based on the contents, the results of the analyze and the critical points of precedent studies to draw the development direction of subway adjacent influence area by using autonomous variables from advanced research. Upon this, drew a conclusion of this study as analyze of influence factors of land value could be a reference material for development of subway adjacent area.