• Journal of the Korean Society of Food Culture
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• v.8 no.1
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• pp.21-42
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• 1993

To understand the dietary culture in Poongki region which was established as Kamrokchon of a folk community, the transmission pattern of the traditional dietary life was investigated by questionnaire to 383 housewives, and the results are as follows : 1) Daily diet : Among 65 traditional main dishes of 6 areas including Kyungsangdo, D’cokguk of Kyungsangdo was consumed most frequently, 87%. General consumption rate based on origin of food was 33.3% of Kyungsangdo, 21.2% of Chungchongdo, 13.1% of Kangwondo, 11.9% of Hwanghaedo, 1.1% of Pyungando and Hamkyungdo, respectively. Among 243 traditional minor dishes, Doenjangjjigye and Kochuchang of Kyungsangdo were most consumed as rates of 91.6%, 89.3%, respectively. General consumption rate based on origin was in order of 38.4% of Kyungsangdo, 19.3% of Chungchongdo, 14.9% of Kwangwondo, 10.4% of Hamkyungdo, 8.7% of Hwanghaedo and 8.3% of Pyungando. 2) Special diet : Among 66 traditional D’ocks, Injeolmi of Hamkyungd was consumed most freguently, 58%. General consumption rate based on origin was in order of 26.3% of Hwanghaedo, 17.6% of Kyungsangdo, 16.1% of Kwangwondo, 16.0% of Hamkyungdo, 13.0% of Pyungando and 11.0% of Chungchongdo. Among 27 cookies, Kangjeong of Hamkyungdo was consumed most frequently 46.7%. General consumption rates based on origin was in order of 55.7% of Hamkyungdo, 22.7% of Kyungsangdo, 2.4% of Pyungando, 5.8% of Kwangwondo, 3.0% of Chungchongdo and 0.4% of Hwanghaedo. Among 19 refresh drinks, Kamju of Kyungsangdo was consumed most frequently, 76.0%. General consumption rate based on origin was in order of 74.3% of Kyungsangdo, 7.8% of Chungchongdo, 6.9% of Hamkyungdo, 5.9% of Hwanghaedo and 5.1% of Kwangwondo. 3) Ceremonial diet : Myyeogguk and Baeksulgi for the 100-Days ceremony and Hynbab and Baeksulgi for the First Birthday were used mainly. For birthday, noodle(59.5%) for lunch besides rice as main dish and Soojeoggwa(37.9%) were served and noodle(30.8%) was used for host. Thirty percent of the varieties used traditionally for Pyehak and 40-50% of the varieties for Jesa(Memorial day) are still prepared currently. 4) Seasonal diet : For Jeolsik(major seasonal diet), the usage rates are as follows : D’ockguk(87%) for Jeongwolchoharu, Ogokbab(77.6%) for Jeongwoldaeborum, Patjuk(72.6%) for Dongji, Samsaeknamul(54.1%) for Chusuk. Relatively high usage rates of Surichi-D’ock(40.5%) for Dano and Mandu(40.5%) for Suddalgumumnal are probably due to the immigrated people from this area and the geographical effect. The consumption rates of Sisik(minor seasonal diet) for Chunghwajeol, Samjinal, Youdooil, Chungyangjeol and Muoil are about 10% and the rates for Chopail and Chilsuk are followed. Gaejang and Nangmyon for Sambok used as a rate of 32%. 5) Others : Table pattern; Table for one person(4.7%), table for two(16.7%), table for several(64.2%), table with chair(14.4%) are used. Serving pattern; All-together style(69.7%), monopoly style(24.0%), personaldish style(6.3%) are used. Cooking ware; Among 95 varieties, Doma and Jangban are used most(62.7%) and Pulmae, Poonju and Budulgori are never used. Nine sorts besides Jeongoltle are used as a rate of less than 1%. About 25% of total subjects were the immigrants from other areas. Some of them were moved in due to Chunggamrok. In conclusion, the usage of the traditional food is thought to be maintained well despite of the rapid change to incustrialized society because the native Kyungsangdo foods are combined with foods from the neighboring Kwangwondo, Chungchongdo and northern area.

• Journal of the Mineralogical Society of Korea
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• v.31 no.1
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• pp.47-55
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• 2018

Talc, hydrous magnesium phyllosilicate, is one of the most popular industrial minerals due to their chemical stability and adsorptivity. While micro-sized talc has long been used as a filler and coating, nano-sized talc recently is attracting attention as additives for improving the stability of nanocomposites. In this study, we produced the nano-sized talc powder by mechanical method using high energy ball mill and investigated the changes in particle size and crystallinity with increasing milling time up to 720 minutes. X-ray diffraction results show that the peak width of talc gradually as the milling proceeded, and after 720 minutes of pulverization, the talc showed an amorphous-like X-ray diffraction pattern. Lase diffraction particle size analysis presents that particle size of talc which was ${\sim}12{\mu}m$ decreased to ${\sim}0.45{\mu}m$ as the milling progressed, but no significant reduction of particle size was observed even after grinding for 120 minutes or more. BET specific surface area, however, steadily increases up to the milling time of 720 minutes, indicating that the particle size and morphology change steadily as the milling progressed. Scanning electron microscope and transmission electron microscope images shows that layered particles of about 100 to 300 nm was aggregated as micro-sized particles after pulverization for 720 minutes. As the grinding time increases, the particle size and morphology of talc continuously change, but the nano-sized talc particles form micro sized agglomerates. These results suggest that there is a critical size along the a, b axes in which the size of plates is reduced even though the grinding proceeds, and the reduction of plate thickness along the c axis leads the increase in specific surface area with further grinding. This study could enhance the understanding of the mechanism of the formation of nano-sized talc by mechanical grinding.

• Economic and Environmental Geology
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• v.41 no.2
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• pp.225-242
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• 2008

The site effect for 23 broadband seismic stations in the southern Korean Peninsula was estimated by using the spectral ratio of coda waves. In principle, the site effect means the pure amplification below the station excluding effects of seismic source and attenuation in the wave transmission. However, the site effect determined in this study is equivalent with the relative site amplification factor to the mean amplification for all stations. A total of 500 three-component seismograms from 35 earthquakes, of which magnitude ranged from 2.5 to 5.1 occurred from January, 2001 to January, 2007 was used to obtain the site amplification factor. The site amplification factors were estimated for the frequency bands centered at 0.2, 0.5, 1, 2, 5, 10, 15, and 20 Hz. It was found that the factors for two horizontal components of transverse and radial records were concordant with each other in the all frequency bands. However, the factor for the vertical component was found to be systematically lower than those for two horizontal components. The factors obtained in the low frequency band below 2 Hz ranged from 0.5 to 1.5 in all seismic stations except for KMA and KIGAM stations in Bagryeongdo (BRD1 and BRD2) of which factor showed high value above 1.5. Some stations such as SEO, SNU, HKU, NPR, and GKPI showed high value above 1.5 in the high frequency band from 5 to 20 Hz. Especially, the factors of GKP1 station represented extremely high value ranging from 1.8 to 7.8. Also, the factors for stations of KWJ, SND, and ULJ showed low value below 0.5. The spatial distribution for the relative amplification factor represented a tendency of being approximately lower in north-eastern area than south-western area in the southern Korean Peninsula.

• Applied Microscopy
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• v.37 no.2
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• pp.83-91
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• 2007

The present study examined the epidermal changes of adhesive disks which occur during attachment in Parthenocissus tricuspidata using scanning and transmission electron microscopy. Several adhesive disks, each covered with a bract, develop from the shoot apical meristem during early development. In the initial stage, the adhesive disks are club-shaped and their upper and lower epidermis are indistinguishable. However, in the actively growing stage, they become spherical and both epidermis are clearly differentiated into the adventitious roots. Prior to wall attachment, the adhesive disks exhibit adaxial convex and abaxial concave shapes, and electron-dense substances are abundant in the vacuoles of epidermal cells. The peripheral area of the adhesive disk is adhered first to the wall surface, while the central area is drawn inward in a vacuum-like state during attachment. As the attachment progresses and the electron-dense substances continue to discharge, the upper and lower epidermis rapidly undergo deterioration and the disks shrink considerably. At this stage, structural changes of the lower epidermis occur much faster than in the upper one. The discharged substance is accumulated on the wall surface, and this aids the attachment of adhesive disks on the wall for long periods. In this manner, the shape and structure of the adhesive disk epidermis change drastically from initial growth to the mature stage. Further, the role of electron-dense substance and shrinkage of the disk during attachment has been discussed in Parthenocissus tricuspidata.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.4
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• pp.253-264
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• 2022

In this study, we investigated the occurrence of viral diseases in the early growth stage of soybean to establish management practices. We collected 83 soybean samples showing abnormal symptoms, approximately 3-4 weeks after seeding in the breeding field of the National Institute of Crop Science. Viruses were detected in the collected samples using reverse transcription polymerase chain reaction (RT-PCR) and metatranscriptome analysis of all those samples. The incidence of viral diseases in the field was less than 1% overall and up to 50% in certain cultivars and lines. RT-PCR and metatranscriptome analysis detected Soybean yellow mottle mosaic virus (SYMMV), Soybean mosaic virus (SMV), Soybean yellow common mosaic virus, Peanut stunt virus, and soybean geminivirus A (SGVA). Among these detected viruses, SYMMV and SMV were identified as major viruses causing infection in the early growth stage of soybean, with detection rates of 53.7% and 42.6%, respectively. Soybeans infected with SYMMV showed typical mosaic symptoms, whereas those infected with SMV showed a variety of symptoms such as mosaic, mottle, stunt, and chlorotic spots. Transmission characteristics of these viruses are variable, such that SMV is primarily transmitted by seeds, whereas SYMMV could be transmitted by insects, soil, and seeds. In this study, SGVA was detected in the early growth stage of soybean, and research on the current status and its effects on soybean after the early growth stage should be conducted.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.2
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• pp.36-40
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• 2011

Purpose: $^{18}F$-FDG injected dose to the patient is quite different between the recommended dose from manufacturer and the actual dose applied to each of hospitals. injection of inappropriate $^{18}F$-FDG dose may not only increase the exposed dose to patients but also reduce the image quality. we thus evaluated the proper $^{18}F$-FDG injected dose to decrease the exposed dose to patients considering the image quality. Materials And Methods: NEMA Nu2-1994 phantom was filled with $^{18}F$-FDG increasing hot cylinder radioactivity concentration to 1, 3, 5, 7, 9 MBq/kg based on the ratio of 4:1 between the hot cylinder and background activity. after completing the transmission scan using ct, emission scan was acquired in 3D mode for 2 minutes 30 seconds/bed. ROI was set up on hot cylinder and background radioactivity region. after measuring $SUV_{max}$ those regions, then analyzed SNR at the points. clinical experiment has been conducted the object of patients who have came to smc from november 2009 to august 2010, 97 patients without having a hepatic lesions were selected. ROI was set up in the liver and thigh area. after measuring $SUV_{max}$, the image quality was compared following the injected dose. Results: in phantom study, as the injected radioactivity concentration per unit mass was 1, 3, 5, 7, 9 MBq/kg, $SUV_{max}$ was 23.1, 24.1, 24.3, 22.8, 23.6 and SNR was shown 0.48, 0.54, 0.56, 0.55, 0.55. according to increment of the injected dose, $SUV_{max}$ and SNR was increased under 5 MBq/kg but they were decreased over 7 MBq/kg. in case of clinical experiment, as increased the injected radioactivity concentration per unit mass was 4.72, 5.34, 6.16, 7.41, 8.68 MBq/kg, $SUV_{max}$ was 2.68, 2.67, 2.26, 1.88, 1.95 and SNR was shown 0.52, 0.53, 0.46, 0.46, 0.44. if the injected dose exceeds 5 MBq/kg, showed a decrease pattern as phantom study. Conclusion: increasing $^{18}F$-FDG injected dose considered patient's body weight improve image quality within a certain range. if it exceeds the range, it can be reduced image quality due to random and scatter coincidences. this study indicates that the optimal injected dose was 5 MBq/kg per unit mass the injected radioactivity concentration in 3d wb pet/ct.

• Progress in Medical Physics
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• v.22 no.4
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• pp.206-215
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• 2011

The purpose of this was to investigate the measurement of fluence dose map for the specific patient quality assurance. The measurement of fluence map was performed using 2D matrixx detector. The absorbed dose was measured by a glass detector, Gafchromic film and ion chamber in Hybrid Optimized VMAT Phantom (HOVP). For 2D Matrixx, the results of comparison were average passing rate $85.22%{\pm}1.7$ (RT_Target), $89.96%{\pm}2.15$ (LT_Target) and $95.14%{\pm}1.18$ (G4). The dose difference was $11.72%{\pm}0.531$, $-11.47%{\pm}0.991$, $7.81%{\pm}0.857$, $-4.14%{\pm}0.761$ at the G1, G2, G3, G4. In HOVP, the results of comparison for film were average passing rate (3%, 3 mm) $93.64%{\pm}3.87$, $90.82%{\pm}0.99$. We were measured an absolute dose in steep gradient area G1, G2, G3, G4 using the glass detector. The difference between the measurement and calculation are 8.3% (G1), -5.4% (G2), 6.1% (G3), 7.2% (G4). The using an Ion-chamber were an average relative dose error $-1.02%{\pm}0.222$ (Rt_target), $0.96%{\pm}0.294$ (Lt_target). Though we need a more study using a transmission detector. However, a measurement of real-time fluence map will be predicting a dose for real-time specific patient quality assurance in volume modulated arc therapy.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.174-175
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• 2012

(In, Ga) N-based III-nitride semiconductor materials have been viewed as the most promising materials for the applications of blue and green light emitting devices such as light-emitting diodes (LEDs) and laser diodes. Although the InGaN alloy can have wide range of visible wavelength by changing the In composition, it is very hard to grow high quality epilayers of In-rich InGaN because of the thermal instability as well as the large lattice and thermal mismatches. In order to avoid phase separation of InGaN, various kinds of structures of InGaN have been studied. If high-quality In-rich InGaN/GaN multiple quantum well (MQW) structures are available, it is expected to achieve highly efficient phosphor-free white LEDs. In this study, we proposed a novel InGaN double hetero-structure grown on GaN nano-pyramids to generate broad-band red-color emission with high quantum efficiency. In this work, we systematically studied the optical properties of the InGaN pyramid structures. The nano-sized hexagonal pyramid structures were grown on the n-type GaN template by metalorganic chemical vapor deposition. SiNx mask was formed on the n-type GaN template with uniformly patterned circle pattern by laser holography. GaN pyramid structures were selectively grown on the opening area of mask by lateral over-growth followed by growth of InGaN/GaN double hetero-structure. The bird's eye-view scanning electron microscope (SEM) image shows that uniform hexagonal pyramid structures are well arranged. We showed that the pyramid structures have high crystal quality and the thickness of InGaN is varied along the height of pyramids via transmission electron microscope. Because the InGaN/GaN double hetero-structure was grown on the nano-pyramid GaN and on the planar GaN, simultaneously, we investigated the comparative study of the optical properties. Photoluminescence (PL) spectra of nano-pyramid sample and planar sample measured at 10 K. Although the growth condition were exactly the same for two samples, the nano-pyramid sample have much lower energy emission centered at 615 nm, compared to 438 nm for planar sample. Moreover, nano-pyramid sample shows broad-band spectrum, which is originate from structural properties of nano-pyramid structure. To study thermal activation energy and potential fluctuation, we measured PL with changing temperature from 10 K to 300 K. We also measured PL with changing the excitation power from 48 ${\mu}W$ to 48 mW. We can discriminate the origin of the broad-band spectra from the defect-related yellow luminescence of GaN by carrying out PL excitation experiments. The nano-pyramid structure provided highly efficient broad-band red-color emission for the future applications of phosphor-free white LEDs.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.284-284
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• 2016

Topological insulator (TI) is a bulk-insulating material with topologically protected Dirac surface states in the band gap. In particular, $Bi_2Se_3$ attracted great attention as a model three-dimensional TI due to its simple electronic structure of the surface states in a relatively large band gap (~0.3 eV). However, experimental efforts using $Bi_2Se_3$ have been difficult due to the abundance of structural defects, which frequently results in the bulk conduction being dominant over the surface conduction in transport due to the bulk doping effects of the defect sites. One promising approach in avoiding this problem is to reduce the structural defects by heteroepitaxially grow $Bi_2Se_3$ on a substrate with a compatible lattice structure, while also preventing surface degradation by encapsulating the pristine interface between $Bi_2Se_3$ and the substrate in a clean growth environment. A particularly promising choice of substrate for the heteroepitaxial growth is hexagonal boron nitride (h-BN), which has the same two-dimensional (2D) van der Waals (vdW) layered structure and hexagonal lattice symmetry as $Bi_2Se_3$. Moreover, since h-BN is a dielectric insulator with a large bandgap energy of 5.97 eV and chemically inert surfaces, it is well suited as a substrate for high mobility electronic transport studies of vdW material systems. Here we report the heteroepitaxial growth and characterization of high quality topological insulator $Bi_2Se_3$ thin films prepared on h-BN layers. Especially, we used molecular beam epitaxy to achieve high quality TI thin films with extremely low defect concentrations and an ideal interface between the films and substrates. To optimize the morphology and microstructural quality of the films, a two-step growth was performed on h-BN layers transferred on transmission electron microscopy (TEM) compatible substrates. The resulting $Bi_2Se_3$ thin films were highly crystalline with atomically smooth terraces over a large area, and the $Bi_2Se_3$ and h-BN exhibited a clear heteroepitaxial relationship with an atomically abrupt and clean interface, as examined by high-resolution TEM. Magnetotransport characterizations revealed that this interface supports a high quality topological surface state devoid of bulk contribution, as evidenced by Hall, Shubnikov-de Haas, and weak anti-localization measurements. We believe that the experimental scheme demonstrated in this talk can serve as a promising method for the preparation of high quality TI thin films as well as many other heterostructures based on 2D vdW layered materials.

• Applied Microscopy
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• v.25 no.2
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• pp.53-64
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• 1995

This study was designed to investigate the morphological alterations of zonula occludens, macula adherences and gap junctions between the hepatocytes in the fasting conditions. Animals (Sprague Dawley, $250{\sim}280g$) were divided into two groups: normal and fasting. The latter were fasted for eight days prior to sampling. Liver tissues were sectioned and replicated after freeze fracturing for the transmission electron microscopy. In the normal rat liver, the interhepatocellular space at the area of some zonula occludens appeared to be widened in thin sections. On the freeze fracture replicas., the zonula occludens appeared as an anastomosing network of $2{\sim}4$ strands or grooves on P or E faces. Free ends and fragments of the strands were observed. In the rat fasted for eight days, the hepatocytes were diminished in size and the organelles were decreased in number and size. The intercellular space was wide at many areas of zonula occludens in thin section. On the freeze fracture replicas, the zonula occludens showed diminution or disappearence of anastomosing network of strands or grooves. Free ends and small fragments of the strands or grooves were frequently encountered. The macula adherens was markedly increased in number in thin sections, although they could not be found on the freeze fracture replicas. The gap junctions were increased in number in thin sections. Small aggregations of the intramembranous particles appeared with larger ones on the freeze fracture replica. The evidences may suggest the followings: (1) The disassembly of zonula occludens in the fasting states is led from the diminished mechanical stress on the luminal surface of bile canaliculus with the impaired secretion of bile components from the hepatocytes. (2) The increase of macula adherens is necessary to maintain the liver parenchyma integrity in the fasting state which leads the hepatocyte to be diminished and finally the intercellular space to be separated. (3) The rise in both number and size of gap junctions is owing to the need of increasing intercellular communication between the hepatocytes during the fasting. (4) The alteration of zonula occludens is easily led by the physiological condition of hepatocytes even in the normal ones.