• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.11
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• pp.1569-1574
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• 2011

In this study, the identification of the irradiated seafood cooking drips from Hizikia fusiformis, Enteroctopus dofleini and Thunnus thynnus was conducted. The physical detection methods used included photo-stimulated luminescence (PSL) and thermoluminescence (TL), and the chemical detection methods were hydrocarbons analysis. In the PSL study, all seafood cooking drip samples showed 260~510 photon counts; thus, the PSL method could not be used for the detection of irradiated seafood cooking drips. The TL method could be used for the detection of irradiated H. fusiformis and E. dofleini cooking drips. In both cooking drips, the shapes of the glow curves indicated a specific peak at 150$^{\circ}C$~250$^{\circ}C$, which made it possible to identify the irradiated samples. The hydrocarbons derived by gamma irradiation of T. thynnus cooking drip were not detected due to low concentration and inconsistent content of fatty acids in the untreated T. thynnus cooking drip.

• Journal of Radiation Industry
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• v.6 no.2
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• pp.119-123
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• 2012

The detection properties of gamma-irradiated (0~10 kGy) dried seaweed, dried shrimp, and seasoned dried filefish were investigated by photo-stimulated luminescence (PSL) and electron spin resonance (ESR). PSL could be used as a detection method on irradiated dried seaweed and dried shrimp as they showed photon counts greater than 5,000 counts/60 s (positive) in the irradiated samples with doses above l kGy. However, PSL could not be applied to detect irradiated seasoned dried filefish, because gamma-irradiated sample at 10 kGy even yielded photon counts less than 700 counts/60 s (negative). The ESR spectroscopy for only dried shrimp revealed specific signals derived from free radicals captured in the shell of shrimp. As a result, it is considered that PSL or ESR methods for detection of gamma-irradiated dried shrimp and only PSL can be used to detect gamma-irradiated seaweed. Furthermore, it is considered that hydrocarbon analysis of seasoned dried filefish containing fat by GC/MS and Thermo Luminance (TL) analysis of dried seaweed should be studied for detection of irradiation.

• Journal of the Mineralogical Society of Korea
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• v.28 no.3
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• pp.245-253
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• 2015

The performance of $TiO_2$ photo-catalytic oxidation process is significantly dependent on the amount of hydroxyl radicals produced during the process, and it is an essential prerequisite to quantify its production. However, precise and accurate methods for quantification of hydroxyl radicals have not been developed so far. For this reason, this study was initiated to compare existing methods for analysis of hydroxyl radicals produced by $TiO_2$ photo-catalytic oxidation and to propose a new method to overcome the limitation of established methods. To simulate $TiO_2$ photo-catalytic oxidation process, Degussa P25 which has been widely used as a standard $TiO_2$ photo-catalyst was used with the dose of 0.05 g/L. The light source of process was UVC mercury low-pressure lamp (11 W, $2,975mW/cm^2$). The results indicate that both potassium iodide (KI)/UV-vis spectrometer and terephthalic acid (TPA)/fluorescence spectrometer methods could be applied to qualitatively measure hydroxyl radicals via detection of triiodide ion ($I_3{^-}$) and 2-hydroxyterephthalic acid which are produced by reactions of iodine ion ($I^-$) and TPA with hydroxyl radicals, respectively. However, it was possible to quantitatively measure hydroxyl radicals using TPA method coupled with high-performance liquid chromatograph (HPLC). The analytical results using TPA/HPLC method show that hydroxyl radical of 0.013 M was produced after 8 hours operation of photo-catalytic oxidation under specific experimental conditions of this study. The proposed method is expected to contribute to precise the evaluation of the performance of photo-catalytic oxidation process.

• 한국지형공간정보학회:학술대회논문집
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• 2004.10a
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• pp.167-173
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• 2004

The erosion(or sediment) reaches very serious level due to the aftermath by the imprudent reclamation on the coast. Continuous studies for long on coastline erosion may be warranted and possible countermeasures proposed because the change of the coastline has been progressed slowly for a long period of time in a wide area. Many experts anticipate that the global sea level's average increase by 19-35 cm due to global warming may certainly have an effect on the coastal erosion throughout the world. Thus, a more rigorous study on the causes of changing coastlines is particularly proposed to find ways to counteract any possible threats against coastal environments. In this study, Ortho aerial photo and hydrographic survey datum were utilized to quantitatively analyze coastal erosion and sediment patterns. This paper also seeks to prove that a parcel under the sea occurred due to relatively significant changes to the coastline. We created Ortho aerial photo using aerial photos taken each decade ('81, '93, '00), overlaid them onto a cadastral registration map, and calculated each amount of erosion and sediment while accounting for the tide level and without considering it. As the result of this study, we could propose that the methods of Ortho aerial photo and the marine observation datum were the effective ways of change detection in erosion, sediment, and artificial reclamation of the coastline for a long time.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.1
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• pp.116-124
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• 2008

This study presents the application of multi-temporal and multi-scale panchromatic aerial photos for change detection in a small urban area. For aerial photos of the scale of 1:20,000 taken in 1987 and 1996 and the scale of 1:37,500 taken in 2000. Pre-processing that make the same conditions to all of the aerial photos was carried out through geometric correction, registration, contrasting, resamplimg, and mosaicking and then change detection were carried out respectively by image differencing and image ratio techniques. As a result, the change of urban features and landcover were able to be detected from panchromatic aerial photos that is single-band images and then the detected change results were compared between both techniques.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.5
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• pp.488-493
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• 2005

This paper presents a method of detecting rotor position for single phase Switched Reluctance Motors(SRMs) using a search coil. In the single phase SRM, mainly Hall effect sensors or photo interrupters have been used to detect the rotor position. But these sensors have many disadvantages. In this paper, low cost and robust characteristics of rotor position detection method are focused in order to compensate for disadvantage of existing sensors. Search coils wound around the stator pole are used for detection of the rotor position in single phase SRM. Rotor position detection is achieved through electromotive force patterns induced by time-varying flux linkage in the search coil. The simulation and experimental results are presented to verify the performance of the proposed method in this paper.

• Journal of Sensor Science and Technology
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• v.10 no.2
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• pp.91-100
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• 2001

A $8{\times}8$ foveated (log-polar) retina chip for edge detection has been designed and fabricated using CMOS technology. Retina chip performs photo-input sensing, edge extraction and motion detection and we focused edge extraction. The pixel distribution follows the log-polar transform having more resolution in the center than in the periphery and can reduce image information selectively. This kind of structure has been already employed in simple image sensors for normal cameras, but never in edge detection retina chip. A scaling mechanism is needed due to the different pixel size from circumference to circumference. A mechanism for current scaling in this research is channel width scaling of MOS transistor. The designed chip has been fabricated using standard $1.5{\mu}m$ single-poly double-metal CMOS technology.

• Transactions of the Society of Information Storage Systems
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• v.1 no.2
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• pp.115-120
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• 2005

As a popularity of a portable digital device such as a cellular phone, a digital camera and a MP3 player is spreading, the demand of the mobile storage device increases rapidly. A bluray technology using 405nm laser diode and objective lens having high NA(Numerical Aperture), 0.85, satisfies a miniaturization and a high capacity which are the requirements of the portable device. To develop SFFOP(small form factor optical pickup), it is prerequisite to minimize the number of optical components and establish evaluation and assembly method of micro optical pickup system as well as mass production method of micro optical component. To minimize optical elements of optical pickup, there have been many researches to use P-HOE(Polarized Holographic Optical Element) due to its extremely small size and versatile function. However, P-HOE is handled and assembled very accurately in SFFOP. In this paper, static error signal detection method is developed for an alignment of P-HOE in SFFOP. Using developed static error signal detection method, P-HOE can be aligned very accurately with real time result of static error signals of pickup such as FES(focusing error signal) and TES(Tracking Error Signal). The developed static error signal detection method is verified by the evaluation of commercialized DVD Pickup. And finally. developed static error signal detection method is applied for the assembly of P-HOE in SFFOP system satisfies specification of BD(Blu-ray Disk).

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.334.2-334.2
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• 2016

Silicon nitride (SiNx:H) films are generally used as passivation layer on solar cell and they are usually made by plasma enhanced chemical vapor deposition (PECVD). In this study, we investigated the properties of silicon nitride (SiNx:H) films made by PECVD. Effects of mixture ratio of process gases with silane (SiH4) and ammonia (NH3) on the passivation qualities of silicon nitride film are evaluated. Passivation properties of SiNx:H are focused by making antireflection properties identical with thickness and refractive index controlled. The absorption coefficient of each film was evaluated by spectrometric ellipsometery and the minority carrier lifetimes were evaluated by quasi-steady-state photo-conductance (QSSPC) measurement. The optical properties were obtained by UV-visible spectrophotometer. The interface properties were measured by capacitance-voltage (C-V) measurement and the film components were identified by Fourier transform infrared spectroscopy (FT-IR) and Rutherford backscattering spectroscopy detection (RBS) - elastic recoil detection (ERD).

• Food Science and Biotechnology
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• v.17 no.5
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• pp.1038-1046
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• 2008

This study was carried out to develop a small-sized biosensor based on surface plasmon resonance (SPR) for the rapid identification of insecticide residues for food safety. The SPR biosensor module consists of a single 770 nm-light emitting diodes (LED) light source, several optical lenses for transferring light, a hemisphere sensor chip, photo detector, A/D converter, power source, and software for signal processing using a computer. Except for the computer, the size and weight of the sensor module are 150 (L)$\times$70 (W)$\times$120 (H) mm and 828 g, respectively. Validation and application procedures were designed to assess refractive index analysis, affinity properties, sensitivity, linearity, limits of detection, and robustness which includes an analysis of baseline stability and reproducibility of ligand immobilization using carbamate (carbofuran and carbaryl) and organophosphate (cadusafos, ethoprofos, and chlorpyrifos) insecticide residues. With direct binding analysis, insecticide residues were detected at less than the minimum 0.01 ppm and analyzed in less than 100 sec with a good linear relationship. Based on these results, we find that the binding interaction with active target groups in enzymes using the miniaturized SPR biosensor could detect low concentrations which satisfy the maximum residue limits for pesticide tolerance in Korea, Japan, and the USA.