• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2000.11a
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• pp.1-14
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• 2000

The Near Infrared region of the energy spectrum was first discovered by Hershel in the year 1800. The principles of NIR is based on light absorption of specific organic chemical bonds. The absorption at each wavelength is measured and a spectre is obtained. The spectre is then treated mathematically and with the absorption data is converted to absolute units via a calibration. In the last two decades it has developed dramatically. With the invention of computers and the ability to treat a large amount of data in a very short time the use of NIR for many different purposes has developed very fast. During the last decade with the aid of very powerful PC's the application of NIR technology has become even more widespread. Now or days development of very robust calibrations can be done in a relatively short time with a minimum of resources. The use of Near Infrared Spectroscopy (NIR) in the Meat industry is relatively new. The first installations were taken into operation in the 80ties. The Meat Industry in often referred to as rather conservative and slow to embrace new technologies, they stay with the old and proven methods. The first NIR instruments used by the Meat Industry, and most other industries, were multipurpose build, which means that the sample presentation was not well suited to this particular application, or many other applications for that sake. As the Meat Industry grows and develops to meet the demands of the modern markets, they realise the need for better control of processes and final products. From the early 90 ties and onward the demand for 'rear time' rapid results starts growing, and some suppliers of NIR instruments (and instruments based on other technologies, like X-ray) start to develop and manufacture instrumentation dedicated to the particular needs of the Meat Industry. Today it is estimated that there are approximately 2000 rapid instruments placed in the Meat industry world-wide. By far most of these are used as at-line or laboratory installations, but the trend and need is moving towards real on-line or in-line solutions. NIR is the most cost effective and reproducible analytical procedure available for the twenty first century.

• Journal of the Korean GEO-environmental Society
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• v.13 no.6
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• pp.73-81
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• 2012

Safety issue for offshore wind-turbine foundation becomes a crucial factor as offshore wind turbines have been scaled up. Correspondingly, there is a demand to understand the effect of soil-structure interaction on to system behavior in geotechnical engineering point of view. The p-y curve method researched in past few decades is one of the most appropriate methodology to analyze the problem. In this study, recently proposed p-y curve models for various rocks are calibrated to analyze the engineering characteristics of seabed of Jeju Island where it is known to be most suitable area for offshore wind energy farm. Step by step calibration process for p-y models is presented. Analysis results show that subgrade reaction generally increases as closer to seabed. It is also shown that the behavioral characteristics of foundation reflect well rock properties in terms of resultant moment, shear force, etc.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.11
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• pp.1133-1137
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• 2011

A novel technique for the fabrication of a glass micropipette-based thermal sensor was developed utilizing inexpensive thermocouple materials. Thermal fluctuation with a resolution of ${\pm}0.002$ K was measured using the fabricated thermal probe. The sensors comprise unleaded low-melting point solder alloy (Sn) as a core metal inside a borosilicate glass pipette coated with a thin film of Ni, creating a thermocouple junction at the tip. The sensor was calibrated using a thermally insulated calibration chamber, the temperature of which can be controlled with a precision of ${\pm}0.1$ K and the thermoelectric power (Seebeck coefficient) of the sensor was recorded from 8.46 to $8.86{\mu}V$/K. The sensor we have produced is both cost-effective and reliable for thermal conductivity measurements of micro-electromechanical systems (MEMS) and biological temperature sensing at the micron level.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.1
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• pp.43-54
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• 2008

Management and control of ammonia at the sources and ambient largely depend on sampling and measurement techniques. Good sampling and measurement techniques provide high quality data. The main purpose of the study is compare the analytical characteristics of the Indolphenol method which is one of the standard method in Korea with automatic analyzers for continued measuring gaseous ammonia. For comparison with other analytical methods, the verification test was designed to evaluate performance parameters; linearity, absorption efficiency, reproducibility and repeatability test, accuracy, and response time test. $R^2$ of calibration curve using IPM and CLM was very high (value is 1.000), but for EcSM $R^2$ value was estimated to be lower than IPM and CLM (as 0.991). The RSD of the CLM ranged from 0.1 to 2.3% over the nine concentration levels measured, %Ds was 0.1 to 10.7%, and average RA over all the measurements was 3.3%. The RSD of IPM and EcSM was ranged from 1.0 to 8.1, 3.9 to 14.0 respectively, and average RA were 8.71, 4.9% respectively. Rise in response times of EcSM was estimated to be 1 minute. It is found to be more sensitive than response time (which ranged from 2 to 9 minute) of CLM. For ammonia concentration measured using the IPM and the CLM from the same ammonia source, linear regression of IPM versus CLM show a slope of 0.805, an intercept of 637 ppb, and $R^2$ of 0.868.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.4
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• pp.691-698
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• 2008

This paper describes a 3.3V 10 bit CMOS digital-to-analog converter with a divided architecture of a 7 MSB and a 3 LSB, which uses an optimal Thermal-to-Binary Decoding method with monotonicity, glitch energy. The output stage utilizes here implements a return-to-zero circuit to obtain the dynamic performance. Most of D/A converters in decoding circuit is complicated, occupies a large chip area. For these problems, this paper describes a D/A converter using an optimal Thermal-to-Binary Decoding method. the designed D/A converter using the CMOS n-well $0.35{\mu}m$ process0. The experimental data shows that the rise/fall time, settling time, and INL/DNL are 1.90ns/2.0ns, 12.79ns, and a less than ${\pm}2.5/{\pm}0.7\;LSB$, respectively. The power dissipation of the D/A converter with a single power supply of 3.3V is about 250mW.

• Journal of Powder Materials
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• v.28 no.3
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• pp.208-215
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• 2021

Metal three-dimensional (3D) printing is an important emerging processing method in powder metallurgy. There are many successful applications of additive manufacturing. However, processing parameters such as laser power and scan speed must be manually optimized despite the development of artificial intelligence. Automatic calibration using information in an additive manufacturing database is desirable. In this study, 15 commercial pure titanium samples are processed under different conditions, and the 3D pore structures are characterized by X-ray tomography. These samples are easily classified into three categories, unmelted, well melted, or overmelted, depending on the laser energy density. Using more than 10,000 projected images for each category, convolutional neural networks are applied, and almost perfect classification of these samples is obtained. This result demonstrates that machine learning methods based on X-ray tomography can be helpful to automatically identify more suitable processing parameters.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.5
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• pp.459-465
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• 2022

This paper reports a method to use a wireless sensor network deployed in the field to real-time monitor soil moisture, warning when the moisture level reaches a specific value, and wirelessly controlling an additional device (LED or water supply system, etc.). In addition, we report all processes related to wireless irrigation system, including field deployment of sensors, real-time monitoring using a smartphone, data calibration, and control of additional devices deployed in the field by smartphone. A commercially available open-source Internet of Things (IoT) platform, NodeMCU, was used, which was combined with a 9V battery, LED and soil humidity sensor to be integrated into a portable prototype. The IoT-based soil humidity sensor prototype deployed in the field was installed next to a tree for on-site demonstration for the measurement of soil humidity in real-time for about 30 hours, and the measured data was successfully transmitted to a smartphone via Wifi. The measurement data were automatically transmitted via e-mail in the form of a text file, stored on the web, followed by analyses and calibrations. The user can check the humidity of the soil real-time through a personal smartphone. When the humidity of a soil reached a specific value, an additional device, an LED device, placed in the field was successfully controlled through the smartphone. This LED can be easily replaced by other electronic devices such as water supplies, which can also be controlled by smartphones. These results show that farmers can not only monitor the condition of the field real-time through a sensor monitoring system manufactured simply at a low cost but also control additional devices such as irrigation facilities from a distance, thereby reducing unnecessary energy consumption and helping improve agricultural productivity.

• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3795-3802
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• 2022

NaI(Tl) scintillation materials are considered to be one of many materials that are used exclusively for γ-ray detection and spectroscopy. The gamma-ray spectrometer is not an easy-to-use device, and the accuracy of the numerical values must be carefully checked based on the rules of the calibration technique. Therefore, accurate information about the detection system and its effectiveness is of greater importance. The purpose of this study is to estimate, using an analytical-numerical formula (ANF), the purely geometric solid angle, geometric efficiency, and total efficiency of a cylindrical NaI(Tl) γ-ray detector with a side-through hole. This type of detector is ideal for scanning fuel rods and pipelines, as well as for performing radio-immunoassays. The study included the calculation of the complex solid angle, in combination with the use of various points like gamma sources, located axially and non-axially inside the through detector side hole, which can be applied in a hypothetical method for calibrating the facility. An extended γ-ray energy range, the detector, source dimensions, "source-to-detector" geometry inside the side-through hole, path lengths of γ-quanta photons crossing the facility, besides the photon average path length inside the detector medium itself, were studied and considered. This study is very important for an expanded future article where the radioactive point source can be replaced by a volume source located inside the side-trough hole of the detector, or by a radioactive pipeline passing through the well. The results provide a good and useful approach to a new generation of detectors that can be used for low-level radiation that needs to be measured efficiently.

• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2725-2732
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• 2020

This paper presents the neutronics benchmark analysis of the first core of the Indonesian multipurpose research reactor RSG-GAS (Reaktor Serba Guna G.A. Siwabessy) calculated by the Serpent Monte Carlo code and the newly released ENDF/B-VIII.0 nuclear data library. RSG-GAS is a 30 MWth pool-type material testing research reactor loaded with plate-type low-enriched uranium fuel using light water as a coolant and moderator and beryllium as a reflector. Two groups of critical benchmark problems are derived on the basis of the criticality and control rod calibration experiments of the first core of RSG-GAS. The calculated results, such as the neutron effective multiplication factor (k) value and the control rod worth are compared with the experimental data. Moreover, additional calculated results, including the neutron spectra in the core, fission rate distribution, burnup calculation, sensitivity coefficients, and kinetics parameters of the first core will be compared with the previous nuclear data libraries (interlibrary comparison) such as ENDF/B-VII.1 and JENDL-4.0. The C/E values of ENDF/B-VIII.0 tend to be slightly higher compared with other nuclear data libraries. Furthermore, the neutron reaction cross-sections of ¹⁶O, ⁹Be, ²³⁵U, ²³⁸U, and S(𝛼,𝛽) of ¹H in H₂O from ENDF/B-VIII.0 have substantial updates; hence, the k sensitivities against these cross-section changes are relatively higher than other isotopes in RSG-GAS. Other important neutronics parameters such as kinetics parameters, control rod worth, and fission rate distribution are similar and consistent among the nuclear data libraries.

• Nuclear Engineering and Technology
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• v.54 no.4
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• pp.1421-1430
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• 2022

The computation of the solid angle and the detector efficiency is considering to be one of the most important factors during the measuring process for the radioactivity, especially the cylindrical γ-ray NaI(Tl) detectors nowadays have applications in several fields such as industry, hazardous for health, the gamma-ray radiation detectors grow to be the main essential instruments in radiation protection sector. In the present work, a generic numerical simulation method (NSM) for calculating the efficiency of the γ-ray spectrometry setup is established. The formulas are suitable for any type of source-to-detector shape and can be valuable to determine the full-energy peak and the total efficiencies and P/T ratio of cylindrical γ-ray NaI(Tl) detector setup concerning the truncated conical radioactive source. This methodology is based on estimate the path length of γ-ray radiation inside the detector active medium, inside the source itself, and the self-attenuation correction factors, which typically use to correct the sample attenuation of the original geometry source. The calculations can be completed in general by using extra reasonable and complicate analytical and numerical techniques than the standard models; especially the effective solid angle, and the detector efficiency have to be calculated in case of the truncated conical radioactive source studied condition. Moreover, the (NSM) can be used for the straight calculations of the γ-ray detector efficiency after the computation of improvement that need in the case of γ-γ coincidence summing (CS). The (NSM) confirmation of the development created by the efficiency transfer method has been achieved by comparing the results of the measuring truncated conical radioactive source with certified nuclide activities with the γ-ray NaI(Tl) detector, and a good agreement was obtained after corrections of (CS). The methodology can be unlimited to find the theoretical efficiencies and modifications equivalent to any geometry by essential sufficiently the physical selective considered situation.