• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1995.10a
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• pp.48-50
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• 1995

The use of acoustics to measure the concentration profile of suspended sediment become increasing common. Field studies have shown the usefulness of remotely measuring the suspended sediment concentration with high spatial and temporal resolution. Techniques that allow for the conversion of the backscattered acoustic intensity into suspended sediment concentration have been developed concurrent with instrumentation. (omitted)

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.11a
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• pp.201-205
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• 1998

Leakage of hydrocarbon compound from underground storage tank has been a significant issue to the hazard of environmental contaminants. It is therefore necessary to develop the measurement technique of hydrocarbon compound concentration. In this study, the possibility of TDR application to measure concentration of hydrocarbon compound, especially diesel, in a sandy soil was investigated. Experiments were conducted in two different conditions. The first one was to measure the resistances of the soil columns packed according to the various ratios of tab water and diesel content in the total voids. The other was to measure the resistance of the soil under the flow condition where diesel oil was allowed to infiltrate into the KCl-saturated soil column. The experimental results showed that there exists a significant relationship between oil% and TDR-measured resistance. This suggests that TDR can be an effective device to measure the concentration of hydrocarbon compound in a soil.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.254-254
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• 2004

Final disposal of radioactive waste generated from Nuclear Power Plant (NPP) requires the detailed information about the characteristics and the quantities of radionuclides in waste package. Most radionuclides are difficult to measure and expensive to assay. Thus it is suggested to the indirect method by which the concentration of the Difficult-to-Measure (DTM) nuclide is estimated using the correlations of concentration-it is called the scaling factor-between Easy-to-Measure (Key) nuclides and DTM nuclides with the measured concentration of the Key nuclide.(omitted)

• Journal of environmental and Sanitary engineering
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• v.10 no.1
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• pp.66-75
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• 1995

This survey is executed about the water quality and improvement measure of Imjin- river. The results are summarized as follows; 1 ) Ammonia nitrogen concentration in tap water was two times higher than drinking water standard. 2) The concentration of BOD in textile wastewater was 235ppm which is higher than wastewater distribution standard and leather wastewater showed high nitrogen concentration. 3) Water quality of the Imjin- river upstream was not in problem but that of Shin- stream showed somewhat high concentration in BOD, COD, and ammonia nitrogen. Especially the detected Cynide compound on the lower of Shin- stream implied seriously polluted condition. 4) The heavy metal in soil of the river bed was not detected but iron, zinc was detected to high concentration. 5) It Is urgently suggested to build more municipal sewage and sanitary treatment plants, and run dredging and river bed rearrangement project. 6) The Construction of the wastewater treatment complexes of relevant industries shall be propelled as soon as possible.

• Journal of Biosystems Engineering
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• v.28 no.5
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• pp.465-468
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• 2003

A microdialysis coupled flow injection amperometric biosensor was calibrated to measure the concentration of glucose using 7 standard samples from 10ml to 70ml of glucose solution. The output of the sensor increased linearly with an increase in the glucose concentration with an $R^2$ correlation of 0.99. The amperometric biosensor was then applied to measure the. glucose concentration of 2 commercial samples(Orange and Pineapple juice) and the results compared with HPLC. Around 12% error was observed in glucose concentration measurements of the samples analyzed. The sensor has potential in rapid measurement once the calibration is done. Potential for on-line sensing is also discussed.

• Journal of Biosystems Engineering
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• v.29 no.6 s.107
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• pp.553-557
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• 2004

A microdialysis coupled flow injection amperometric $({\mu}FIA)$ biosensor was calibrated to measure the concentration of sucrose using 11 standard samples from 2 ml to 70 ml of sucrose solution. The output of the sensor increased linearly with an increase in the sucrose concentration with an $r^2$ correlation of 0.99. The amperometric biosensor was then applied to measure the sucrose concentration of 4 commercial samples (Orange and Pineapple juices, Pepsi, Sprite) and the results compared with those by HPLC. Around $20\~30\%$ error was observed in sucrose concentration measurements of the samples analyzed. The sensor has potential in rapid measurement once the calibration is done. Potential for on-line sensing is also discussed.

• Applied Chemistry for Engineering
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• v.34 no.2
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• pp.131-136
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• 2023

We developed a method to measure the concentration of highly concentrated colored samples using color coordinates. We present a color analysis to estimate the concentration of highly concentrated binary solutions with an empirical function and apply it to estimate the kinetics of a catalytic irreversible reaction of resazurin to resorufin. The developed method enabled one to measure the concentration of solutions whose range of concentrations is nonlinear and beyond the limit of UV-vis spectroscopic measurement directly without dilution.

• Journal of Korea Trade
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• v.25 no.5
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• pp.93-109
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• 2021

Purpose - The logistics industry is often featured by its location relevance and industrial concentration. Industrial concentration is conducive to the effective transmission of information by reducing transaction costs and improving transaction efficiency, thus promoting the development of trade. The main purpose of this paper is to measure the spatial total factor productivity and location quotient of the logistics industry in Korea, and to study the impact of the logistics industry efficiency and agglomeration effect on import and export trade in Korea. Design/methodology - First, used the spatial stochastic frontier method to measure the spatial total factor productivity of the logistics industry in Korea, this serves as the efficiency index of the logistics industry in various regions of Korea. Second, calculated the location quotient (LQ) of the logistics industry to measure the industry's concentration degree. Third, employed a spatial econometric model to analyze the impacts of factors such as the efficiency and concentration levels of the logistics industry on import and export trade in Korea. Findings - This study's main findings can be summarized as follows: this study found that the overall efficiency of the logistics industry in Korea needs to be improved, even though it showed an upward trend in all regions of the country; Moreover, the agglomeration level of Korea's logistics industry needs to be improved; Finally, the positive spatial correlation and industrial agglomeration effect of Korea's logistics industry had a positive impact on the country's import and export trade. Originality/value - This study is innovative in terms of research perspective and methods. Most of the previous studies have measured the development level of the logistics industry using the logistics performance index (LPI), Fewer studies have assessed through the spatial total factor productivity and location quotient of the logistics industry in Korea to measure the efficiency index of the logistics industry in various regions of Korea and concentration degree, as well as there was almost no study on the impact of logistics industry efficiency and agglomeration effect on import and export trade in Korea. This study addresses this limitation by analyzing the impacts of the efficiency and agglomeration effect of the logistics industry on import and export trade in Korea.

• Journal of the Korean Society of Visualization
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• v.9 no.1
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• pp.36-41
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• 2011

It is highly needed to measure the dissolved oxygen (DO) concentration field in water for a variety of purposes such as biological, industrial, environmental monitoring and medical application. Application of PSP (Pressure Sensitive Paint) which is sensitive to oxygen concentration has been carried out to measure DO concentration field using PtOEP/PS film and intensity based method under the UV-LEDs illumination. A micro round water jet having 100% of DO was obliquely impinged on to a PtOEP/PS film coated plate placed in a 0% of DO water container. DO concentration fields on the impinging plate were quantitatively visualized with a $2.94\;{\mu}m$ of spatial resolution. Through pixel-by-pixel calibration, uncertainty of each pixel by different sensitivity, different dye concentration and non-uniformity of illumination was removed. It is demonstrated that the high DO concentration region was coincided with the impingement area. The DO concentration gradient due to DO diffusion was affected by Reynolds number.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.1
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• pp.31-37
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• 1999

In order to predict thermodynamic performance of refrigeration system, it is required to know the oil concentration of the refrigerant/oil mixture. The current method to measure the oil concentration is to extract the working mixture and then to measure the oil weight. However, it is Quite necessary to estimate oil concentration without any extraction of the working fluid. In this study a new method and working equation is presented as follows. It is based on the measurement of spedific gravity and temperature : $$C=a+b{\times}t+c{\times}t^2+(d+e{\times}t+f{\times}t^2){\times}SG$$ C is oil concentration, t is temperature($^{\circ}C$), SG is specific gravity of mixture and a~f is coefficients. The oil concentration ranges over 0~12 wt% and the temperature ranges over $20{\sim}50^{\circ}C$. The specific gravity and temperature are measured using the on-line densimeter and thermometer. This working equation enables to predict the oil concentration without any extraction of the mixture. This equation can be applied for R-12/Naphthenic oil and R-134a/POE oil oiquid mixtures.