• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.8
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• pp.790-796
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• 2002

In our country, historically beautiful and significant wooden architectures are preserved as the cultural properties. For a long time, however, the architectures are often exposed to rough environmental conditions, such as weathering, insect attack, etc. This may lead to deterioration of structural integrity of the architectures. Therefore, it is necessary to diagnose wooden architectures in advance. In this paper, the possibility of a subsurface-penetrating radar(SPR) fur non-destructive testing(NDT) of wooden architectures is investigated by using the three-dimensional finite-difference time-domain(FDTD) simulation and actual laboratory measurement.

• Proceedings of the Korean Reliability Society Conference
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• 2005.06a
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• pp.303-305
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• 2005

Recently, various plastics are used for improvement of reliability and thermal stability of electronic goods. But, it is difficult to choose suitable balance of grade resin to each other product property. Selection of high efficiency resin is becoming inescapable circumstance according to change of reflow temperature of product and development of product following to lead free. Using a inexpensive and reasonable resin, that sustain a uniform performance of product quality. It is make a robust product and increase a company's competitive power. Hereupon, I introduce example that use ESPI methods of thermal deformation analysis of product using in our company product. I try to refer to a structural weak point detection of real time measurement of electronic parts instead of mechanical and chemical measurement of specimen type.

• Journal of the Semiconductor & Display Technology
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• v.20 no.2
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• pp.103-108
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• 2021

The TCD is used as one of the indicators for determining whether TSV Hole is defective. If the TCD is not normal size, it can lead to contamination of the CMP equipment or failure to connect the upper and lower chips. We propose a deep learning model for measuring the TCD. To verify the performance of the proposed model, we compared the prediction results of the proposed model for 2461 via holes with the CD-SEM measurement data and the prediction results of the existing model. Although the number of trainable parameters in the proposed model was about one two-thousandth of the existing model, the results were comparable. The experiment showed that the correlation between CD-SEM and the prediction results of the proposed model measured 98%, the mean absolute difference was 0.051um, the standard deviation of the absolute difference was 0.045um, and the maximum absolute difference was 0.299um on average.

• Journal of the Korean Society of Visualization
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• v.21 no.1
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• pp.74-79
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• 2023

Thrombogenesis, which is the process of blood clot formation, can be initiated by platelet activation. Excessive formation of blood clot in the bloodstream can lead to thrombosis. Therefore, when dealing with patients with disseminated intravascular coagulation (DIC) or children, it is necessary to use small amounts of blood. Hence, it is important to develop methods for the rapid and accurate measurement of the platelet function using a small amount of blood. In this study, 3D printing technology was utilized to facilitate the production of micro channels. The amount of platelet adhesion in smokers and non-smokers was compared by repeatedly exposing the structure of the channel to adjust the number of blood injections and facilitate thrombosis attachment to simple stenosis structures.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.139-142
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• 2020

NB-IoT(Narrow Band Internet of Things) is an emerging LPWAN(Low Power Wide Area Network) radio technology. NB-IoT has many advantages like low power, low cost, and high coverage. However low bandwidth and low sampling rates also lead to poor positioning accuracy. This paper proposed a solution to optimize positioning accuracy under the OTDOA(Observed Time Difference of Arrival) approach by utilizing MLR(Multiple Linear Regression) models. Through the MLR model to predict the influence degree of weather(temperature, humidity, light intensity and air pressure) on the arrival time of signal transmission to improve the measurement accuracy. The improvement of measurement accuracy can greatly improve IoT applications based on NB-IoT.

• Analytical Science and Technology
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• v.16 no.2
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• pp.152-158
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• 2003

This study was conducted to evaluate two sample digestion procedures and instrumental determination parameters for analysis of lead in bone. Amputated human legs were treated by acid digestion or microwave dissolution prior to spectrometric analysis. Inductively coupled plasma mass spectrometry (ICP-MS) and graphite furnace atomic absorption spectrometry (GF-AAS) were used for determining bone lead levels. Recovery efficiencies using standard reference material from acid digestion measured by ICP-MS were in good agreement with those of the certified value, but in cases of acid digestion by GF-AAS and microwave digestion by both two methods, recovery underestimated and overestimated, respectively. For the bone samples, the lead concentrations obtained by ICP-MS after acid digestionwere in good agreement with those by GF-AAS (correlation coefficient = 0.983), but GF-AAS gave systematically higher values than ICP-MS. While a good agreement between two analytical methods after microwave digestion was also obtained (correlation coefficient = 0.950), bone lead concentrations from microwave were relatively higher than those from acid digestion. In conclusion, the use of the simple nitric acid digestion procedure at an ambient temperature coupled to ICP-MS seems to be efficient for the determination of lead in bone in consideration for both the convenience and validity.

• Journal of the Korean Society of Radiology
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• v.16 no.6
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• pp.719-725
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• 2022

This study aimed to measure, quantitatively evaluate, and set the criteria for the minimum lead(Pb) shield thickness per level of clinically applied electron beam energy. The lead shield thickness per electron beam energy was measured using the primary field 95% reduction based on the open field at the depth of maximum dose (d_max) and depth from the surface as the reference depth of tissue dose(10 mm). The measured values were 1.906 mmPb and 1.992 mmPb at the d_max and 10 mm, respectively, regarding the lead shield thickness for 6 MeV electron beam; 2.746 mmPb and 3.743 mmPb for 9 MeV electron beam, 3.718 mmPb and 6.093 mmPb for 12 MeV electron beam, 7.300 mmPb and 15.270 mmPb for 16 MeV electron beam, and 16.825 mmPb and 25.090 mmPb for 20 MeV electron beam. Consequently, a thicker lead shield was required if the measurement was at 10 mm. The required lead shield thickness was also higher than that of the theoretical formula for electron beams of ≥ 16 MeV.

• Journal of the Korean Society of Radiology
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• v.16 no.6
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• pp.687-695
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• 2022

To find a 3D printer material that can replace lead used as a shield for high-energy electron beam treatment, the shielding composites were simulated by using MCNP6 programs. The Percent Depth Dose (PDD), Flatness, and Symmetry of linear accelerators emitting high-energy electron beams were measured, and the linear accelerator was compared with MCNP6 after simulation, confirming that the source term between the actual measurement and simulation was consistent. By simulating the lead shield, the appropriate thickness of the lead shield capable of shielding 95% or more of the absorbed dose was selected. Based on the absorption dose data for lead shield with a thickness of 3 mm, the shielding performance was analyzed by simulating 1, 5, 10, and 15 mm thicknesses of ABS+W (10%), ABS+Bi (10%), and PLA+Fe (10%). Each prototype was manufactured with a 3D printer, measured and analyzed under the same conditions as in the simulation, and found that when ABS+W (10%) material was formed to have a thickness of at least 10mm, it had a shielding performance that could replace lead with a thickness of 3mm. The surface morphology and atomic composition of the ABS+W (10%) material were evaluated using a scanning electron microscope (SEM) and an energy dispersive X-ray spectrometer (EDS). From these results, it was confirmed that replacing the commercialized lead shield with ABS+W (10%) material not only produces a shielding effect such as lead, but also can be customized to patients using a 3D printer, which can be very useful for high-energy electron beam treatment.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.4
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• pp.306-312
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• 2015

The measurement of histamine is to determine the degree of allergy because the allergic reaction can lead to the release of histamine. In general, the antigen-antibody reaction was quantified by measuring absorbance using a microplate reader. In this study, we compare the method using a general antigen-antibody reaction and the method using a high performance liquid chromatography mass spectrometer (HPLC-MS) of chemical analysis in the measurement of histamine secretion. The cell line used was RBL-2H3, an allergic reaction was induced by stimulation with C48/80 (compound 48/80). Allergy-induced cells degranulation rate was confirmed by measurement of ${\beta}$-hexosaminidase and cytotoxicity was performed for the validity of the experiment. The quantitative determination of histamine showed a significant difference, since the quantitative limit of the measurement by the antigen-antibody reaction was 10.257 ppm while the quantitative limit of the measurement by HPLC-MS was 0.020 ppm. Measurement of histamine in allergic activity and anti-allergy tests showed that the HPLC-MS analysis rather than the analysis of the antigen-antibody reaction is a more precise and accurate test.

• Journal of Information Technology Services
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• v.10 no.4
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• pp.171-189
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• 2011

KAs information and knowledge are increasingly becoming more important in the knowledge-driven society, knowledge management, as a very important management paradigm, is securing firm position in private and public sectors. Complying with this paradigm, government-funded research institutes in science-technology sector are actively utilizing knowledge management by employing knowledge management system and evaluating its applications' performance. The purpose of this study is to develop evaluation items and measurement indices to rationally measure knowledge management performance of the government-funded research institutes and to verify the feasibility of applying these evaluation items and indices. To achieve this research goal, the evaluation model of knowledge management performance was constructed by reviewing and integrating the existing studies, and subsequently, evaluation areas, evaluation items, measurement indices were derived from this evaluation model. Also, the feasibility analysis on the evaluation items and measurement indices was performed by means of FGI(Focus Group Interview) with the knowledge management experts belonging to Korean government-funded institutions in science-technology sector. The implications of this study are as follows : in theoretical perspective, this study has proposed a criterion frame to evaluate knowledge management performance, and has rationally drawn evaluation items and measurement indices from the criterion frame. And in practical perspective, this study has improved the validity and practicality of the measurement indices, which can lead to more reasonable and easier evaluation of knowledge management performance of the government-funded research institutes.