• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.1
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• pp.89-96
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• 2022

In this paper, to evaluate the output quality of the cementitious composite mixture for printing with the ME method for construction 3D printer, visual inspection of the output appearance and the dimensional error rate, compressive strength and flexural strength of the output were measured. As a result of the test, the mixing design with excellent output appearance was P1-2, P1-4, P2-5, P2-6, and the mixing design with good output appearance was P0-1, P1-1, P1-3, P1-6, P1-7 and P2-4. Of these mixing designs, P0-1 and P2-6 had the lowest dimensional error rates As a result of evaluating the compressive strength and flexural strength of the various mixing designs, the Mixing design with excellent output designs showed good mechnical properties. However, mixing designs with excellent mechanical properties does not necessarily have excellent output quality. Therefore, in order to accurately evaluate the output quality, it is judged that visual inspection and dimensional error rate inspection should be performed first, and then the mechanical characteristics should be reviewed.

• Journal of the Korean GEO-environmental Society
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• v.23 no.8
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• pp.11-16
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• 2022

The compaction process using vibrating rollers in road construction is essential to increase soil stiffness in earthworks. Currently, there is no clear standard for the operation method of the compaction roller during compaction. Although simple quality inspection techniques have been developed, plate load test (PLT) and field density test (FDT) are the most frequently used test methods to evaluate the degree of compaction during road construction as the most frequently used quality inspection methods. However, both inspection methods are inefficient because they cannot perform quality inspection in all sections due to time and cost reasons. In this study, we analyzed how the operating conditions of vibrating rollers affect the compaction quality. An intelligent quality management system, which is a currently developed and commercialized technology, was used to obtain quality inspection results in all sections. As a result of the test, it was analyzed that the speed and vibration direction of the compaction roller had an effect on the compaction degree, and it was found that the compaction direction had no effect on the compaction degree.

• Korean journal of food and cookery science
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• v.11 no.2
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• pp.93-97
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• 1995

Effects of added ginger juice in Yackwa on the sensory quality and the lipid oxidation were studied. Also effects of soaking on the lipid oxidation were examined. There were no significant differences between Yackwa without adding ginger juice and ones with adding ginger juice on texture, shape, color. However, Yackwa, with ginger juice more than 1 tea spoon(1.5) of ginger juice per 1 cup of flour, was better than one without ginger juice on taste, flavor and overall acceptibility. Added ginger juice showed the antioxidant effect during frying in oil and storage at room temperature. The higher the amount of ginger juice was added, the slower of lipid oxidation was resulted in Yackwa. Yackwa soaked in syrup or in honey showed lower lipid oxidation than one without soaking during storage at room temperature. The antioxidant effect of soaking in honey was higher than one of soaking In syrup.

• Journal of Korean Society of Steel Construction
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• v.11 no.1 s.38
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• pp.1-11
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• 1999

The aim of this study is to construct a machine vision monitoring system for an automatic visual inspection of weld joint in steel structure. An image processing algorithm for a visual weld defects detection on weld bead is developed using the intensity image. An optic system for getting four intensity images was set as a fixed camera position and four different illumination directions. The input images were thresholded and segmented after a suitable preprocessing and the features of each region were defined and calculated. The features were used in the detection and the classification of the visual weld defects. It is confirmed that the developed algorithm can detect weld defects that could not be detected by previously developed techniques. The recognized results were evaluated and compared to expert inspectors' results.

• Journal of the Korean Solar Energy Society
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• v.32 no.5
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• pp.1-10
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• 2012

This paper proposes a modeling and controller design approach for a wind-diesel hybrid system including dump load. Wind turbine depends on nature such as wind speed. It causes power fluctuations of wind turbine. Excessive power fluctuation at stand-alone power grid is even worse than large-scale power grid. The proposed control scheme for power quality is fuzzy PI controller. This controller has advantages of PI and fuzzy controller. The proposed model is carried out by using Matlab/Simulink simulation program. In the simulation study, the proposed controller is compared with a conventional PI controller. Simulation results show that the proposed controller is more effective against disturbances caused by wind speed and load variation than the PI controller, and thus it contributes to a better quality wind-diesel hybrid power system.

• Journal of the Korean Solar Energy Society
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• v.29 no.4
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• pp.41-47
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• 2009

Wind/diesel hybrid operation can be one of the most effective option for electrical power production at a remote area such as Antarctica. The king Sejong station at Antarctica relies its power production on diesel engines and diesel oil is supplied every other year by ships. However, the oil transportation processes are liable to potential oil spillage caused by the floating ice around the King George island. The long-term storage of the oil at the station can also contaminate the surrounding soils. A l0kW wind turbine has been installed to save oil consumption and operated in connection with the diesel generators since 2006. The diesel engine that operated poorly during the first year of installation was replaced in 2008 to enhance power production an recent measurements indicate that both diesel power quality and the wind turbine availability have been dramatically improved by the replacement. This report discusses electrical power qualities of wind/diesel hybrid system operating at an isolated micro gird located in the king Sejong station. Our experience reveals that the similar technologies can be applied to domestic islands, for example, in the south sea.

• Journal of the Korean GEO-environmental Society
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• v.13 no.6
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• pp.41-50
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• 2012

In general, it is critical that grout consistency permit the complete filling of void space without segregation of ingredients. Recently, the antiwashout agent is used on underwater grout materials for preventing the grout from the segregation in water. This study introduces a new type of antiwashout underwater and flowable grout material using viscous modifiers and its characteristics comparing with conventional grout materials in fresh and sea water. It is found that the antiwashout underwater grout both in fresh and sea water has enough strength and good resistance to segregation.

• Journal of the Korean Solar Energy Society
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• v.27 no.1
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• pp.19-27
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• 2007

The Data quality management system(DQMS) organizes and helps manage and process time sequence data usually collected in monitoring networks and programs. DQMS places particular emphasis on data qualify while maintaining a highly organized and convenient structure for data. It operates with in a flexible and powerful commercial relational data base environment which can readily link to other software platforms from local spreadsheets to network server. The Korea Institute of Energy Research(KIER) has been solar radiation data since May, 1991 for 16 different locations. KIER's new data is expected to be extensively used by designer and researchers of solar systems in lieu of unreliable old ones. Unfortunately, the quality of the data has not always been properly mentioned. The purpose of this study is to systematically identify errors in such data set using DQMS in an effort to rehabilitate error-ridden old data. DET successfully uncovered solar radiation data that had questionable quality.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.7B
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• pp.565-577
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• 2012

Recently, cable operators are providing broadcast and IP based services using Hybrid Fiber Coaxial(HFC) networks while securing frequency band for video contents and convergence services are becoming an important issue. But, HFC networks have difficulty of securing frequency band, because they are used for broadcasting service based on MPEG. Therefore, it is necessary to find out a method to go broadband. Radio Frequency over Glass(RFoG), one of the methods to go broadband, is advantageous in the sense that it can overcome bandwidth limit and simplifies the structure. In this paper, we find characteristic and standard of RFoG and services. And we also find advantage of RFoG by evaluating performance.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.11a
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• pp.109-110
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• 2003

본 시험은 스테비아 부산물의 사료적 가치를 구명하기 위하여 산란계 사료에 첨가하여 산란계의 생산성, 난 품질, 계란의 지방산에 미치는 영향을 고찰하였다. 공시계는 78주령 하이라인 360수로 강제환우후 5％ 산란시기에 시행하여 총 20주 동안 사양시험을 시행하였다. 스테비아 부산물을 산란계 사료에 0, 2, 4, 8 ％를 첨가하여 동일한 에너지(2,800 kcal/kg)와 단백질(16 ％) 수준으로 급여하였으며, 처리구당 5반복, 반복당 18수씩 총 360수를 공시하였다. 시험기간 20주 동안, 총 산란율, 난중, 산란량, 사료요구율은 스테비아 부산물 급여구와 대조구 사이에 유의적인 차이는 없었다. 스테비아 부산물의 급여가 계란의 난 품질에 미치는 영향에서 난각강도, 난각두께, 난백고 및 Haugh Unit는 대조구와 차이가 없었지만, 난황색도는 스테비아 부산물의 급여수준이 증가할수록 높은 수치를 보여 스테비아 4 ％와 8 ％ 급여구는 대조구에 비하여 유의적으로 증가하였다. 계란의 당 전이도 시험에서는 스테비아 부산물을 급여하여 생산된 계란과 대조구 사이에 차이가 없었다. 계란의 지방산 함량은 스테비아 부산물 2 ％와 4 % 급여구가 포화지방산은 감소하였고, 단가 불포화지방산은 유의적으로 증가하였다. 이러한 결과 산란계 사료에서 스테비아 부산물은 원료사료로서 8 ％까지 가능하였다.