• Analytical Science and Technology
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• v.19 no.6
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• pp.460-467
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• 2006

Carbon-coated $TiO_2$ was prepared by $CCl_4$ solvent mixing method with different heat treatment temperature (HTT). Since the carbon layers derived from pitch on the $TiO_2$ particles were porous, the carbon-coated $TiO_2$ sample series showed a good adsorptivity and photo decomposition activity. The BET surface area was decreased by the increasing of the heat treatment temperature. The SEM results present to the characterization of surface texture on the carbon-coated $TiO_2$ sample and carbon distributions on the surfaces for all the materials used. The main elements of C, O and Ti were shown from EDX spectra. And the quantity of these elements is very rich in the samples. From XRD data, the pristine anatase peaks were observed in the X-ray diffraction patterns for the carbon-coated $TiO_2$ at the different HTTs. However, the rutile peaks were observed for the carbon-coated $TiO_2$ at HTT of 1073 K and 1123 K. Finally, the excellent photocatalytic activity of carbon-coated $TiO_2$ with UV-vis spectra between absorbance and time could be attributed to the homogeneous coated carbon on the external surface and structural phase transform, and the photocatalytic activity was decreased by the increasing of the HTT.

• Journal of Radiation Protection and Research
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• v.32 no.3
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• pp.123-133
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• 2007

Z-axis automatic tube current modulation technique automatically adjusts tube current based on size of body region scanned. The purpose of the current study was to compare noise, and radiation dose of multi-detector row CT (MDCT) of lower extremity performed with Z-axis modulation technique of automatic tube current modulation with manual selection fixed tube current. Fifty consecutive underwent MDCT venography of lower extremity with use of a MDCT scanner fixed tube current and Z-axis automatic tube current modulation technique (10, 11 and 12 HU noise index, $70{\sim}450\;mA$). Scanning parameters included 120 kVp, 0.5 second gantry rotation time, 1.35:1 beam pitch, and 1 mm reconstructed section thickness. For each subject, images obtained with Z-axis modulation were compared with previous images obtained with fixed tube current (200, 250, 300 mA) and with other parameters identical. Images were compared for noise at five levels: iliac, femoral, popliteal, tibial, and peroneal vein of lower extremity. Tube current and gantry rotation time used for acquisitions at these levels were recorded. All CT examinations of study and control groups were diagnostically acceptable, though objective noise was significantly more with Z-axis automatic tube current modulation. Compared with fixed tube current, 2-axis modulation resulted in reduction of CTDIvol (range, $-6.5%{\sim}-35.6%$) and DLP (range, $-0.2%{\sim}-20.2%$). Compared with manually selected fixed tube current, 2-axis automatic tube current modulation resulted in reduced radiation dose at MDCT of lower extremity venography.

• Journal of radiological science and technology
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• v.28 no.4
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• pp.279-286
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• 2005

Purpose : There are two modalities, those are small bowel series(SBS) and abdominal pelvic computed tomography(CT), for diagnosis of small bowel disease. The aim of this study is to lend radiological technologists who are doing the two modalities assistance in the understanding characteristic of disease by comparing the two results. Meterials and method : 284 patients were examined the two SBS and abdominal pelvic CT together from 1999 to 2003. 250 ml $BaSO_4$ suspension 40 w/v% and 600ml carboxy methyl cellulose 0.5 w/v% were used for SBS. Abdominal Pelvic CT was examined in one hour before taking 450 ml $BaSO_4$ suspension 1.5 w/v%. The CT scan was done in 72 sec after 150 ml contrast media injection. the used protocol was helical mode 5:5 mm pitch 1.375:1, speed 27.50, exposure 120 kv, 240 mA, tube rotation time 0.5 sec. the statistic analysis was conducted with statistical program SPSS 10 version with frequency and crossing analysis. P-value less than 0.05 were considered significant. Results : In the results of SBS, normal findings were 131 patients(46.1%), inflammatory bowel disease(IBD) 64(22.9%), ischemia+ileocolitis+vasculitis 22(7.7%), Obstruction+stricture 21(7.7%) and Others 45(15.9%). In the results of abdominal pelvic CT, normal findings were 103 patients(36.3%), inflammatory bowel disease 65(22.9%), wall thickening+lymphadenopathy 42(14.8%), Fluid collection 17(6%), and Others 57case(20%). The same results of the two were 130patients(45.8%). 30patients(10.6%) of normal finding in SBS were diagnosed as wall thickening+lymphadenopathy and IBD in CT, and 15patients(5.3%) of normal finding in CT were diagnosed as ischemia+ileocolitis+vasculitis, mass and IBD in SBS(p<0.05). Transit time delay was diagnosed in 10patients(3.5%) on only SBS, wall thickening+lymphadenopathy was diagnosed in 20patients(7%) in only CT(p<0.05). Conclusion : We think that proper examination method will be selected in the small bowel disease, if we understand the characteristics of the disease and method.

• Journal of radiological science and technology
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• v.32 no.3
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• pp.299-306
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• 2009

Purpose : To compare radiation dose for coronary CT angiography (CTA) obtained with 6 examination protocols such as a retrospectively ECG gated helical scan, a prospectively ECG gated sequential scan, low kVp technique, and cardiac dose modulation technique. Materials and Methods : Coronary CTA was performed by using 6 current clinical protocols to evaluate effective dose and organ dose in primary beam area with anthropomorphic female phantom and glass dosimetric system in 64 channel multi-detector CT. After acquiring topograms of frontal and lateral projection with 80 kVp and 10 mA, main coronary scan was done with 0.35 sec tube rotation time, 40 mm collimation ($0.625\;mm{\times}64\;ea$), small scan field of view (32 cm diameter), 105 mm scan length. Heart beat rate of phantom was maintained 60 bpm in ECG gating. In constant mAs technique 120 kVp, 600 mA was used, and 100 kVp for low kVp technique. In a retrospectively ECG gated helical CT technique 0.22 pitch was used, peak mA (600 mA) was adopted in range of $40{\sim}80%$ of R-R interval and 120mA(80% reduction) in others with cardiac dose modulation. And 210 mAs was used without cardiac dose modulation. In a prospectively ECG gated sequential CT technique data were acquired at 75% R-R interval (middle diastolic phase in cardiac cycle), and 120 msec additional padding of the tube-on time was used. For effective dose calculation region specific conversion factor of dose length product in thorax was used, which was recommended by EUR 16262. Results : The mean effective dose for conventional coronary CTA without cardiac dose modulation in a retrospectively ECG gated helical scan was 17.8 mSv, and mean organ dose of heart was 103.8 mGy. With low kVp and cardiac dose modulation the mean effective dose showed 54.5% reduction, and heart dose showed 52.3% reduction, compared with that of conventional coronary CTA. And at the sequential scan(SnapShot pulse mode) under prospective ECG gating the mean effective dose was 4.9 mSv, this represents an 72.5% reduction compared with that of conventional coronary CTA. And heart dose was 33.8 mGy, this represents 67.4% reduction. In the sequential scan technique under prospective ECG gating with low kVp the mean effective dose was 3.0 mSv, this represents an 83.2% reduction compared with that of conventional coronary CTA. And heart dose was 17.7 mGy, this represents an 82.9% reduction. Conclusion : In coronary CTA at retrospectively ECG gated helical scan, cardiac dose modulation technique using low kVp reduced dose to 50% above compared with the conventional helical scan. And the prospectively ECG gated sequential scan offers substantially reduced dose compared with the traditional retrospectively ECG gated helical scan.

• Journal of the Korean Geotechnical Society
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• v.31 no.5
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• pp.5-21
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• 2015

An energy pile is a novel type of ground heat exchangers (GHEX's) which sets up heat exchange pipes inside a pile foundation, and allows to circulate a working fluid through the pipe for exchanging thermal energy with the surrounding ground stratum. Using existing foundation structure, the energy pile can function not only as a structural foundation but also as a GHEX. In this paper, six full-scale energy piles were constructed in a test bed with various configurations of the heat exchange pipe inside large-diameter cast-in-place piles, that is, three parallel U-type heat exchangers (5, 8 and 10 pairs), two coil type heat exchangers (with a 500 mm and 200 mm pitch), and one S-type heat exchanger. During constructing the energy piles, the constructability of each energy pile was evaluated with consideration of the installation time, the number of workers and any difficulty for installing. In order to evaluate the thermal performance of energy piles, the thermal performance tests were carried out by applying intermittent (8 hours operating-16 hours pause) artificial cooling operation to simulate a cooling load for commercial buildings. Through the thermal performance tests, the heat exchange rates of the six energy piles were evaluated in terms of the heat exchange amount normalized with the length of energy pile and/or the length of heat exchange pipe. Finally, the economic feasibility of energy pile was evaluated according to the various types of heat exchange pipe by calculating demanded expenses per 1 W/m based on the thermal performance test results along with the market value of heat exchange pipes and labor cost.

• (The) Research of the performance art and culture
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• no.36
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• pp.415-440
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• 2018

On September 23, 2015, the Ministry of Education announced the 2015 revision of educational curriculum which aimed at 'cultivating creative talents' based on the Article 23, Section 2 of the Elementary and Secondary Education Law. As a result, music curriculum have also been partially revised, which seems to maintain the 2009 revision of music curriculum. Although Jeongganbo 井間譜 is already exposed in the music curriculum for the third and forth grades of elementary school, the learning content about how to read Jeongganbo and how to express the pitch and length of sound including the origin of its name and the background of its invention are dealt with specifically in the fifth and sixth grades. Jeongganbo is known as the oldest mensural notation in the Orient created by King Sejong of the Joseon Dynasty in the middle of the $15^{th}$ century, and it was used for the first time in Sejong sillok akbo 世宗實錄樂譜 (Scores in the Annals of King Sejong), the oldest musical score still in existence. However, in the music textbooks as well as the most of specialized books related to the Korean traditional music, it is uncritically accepted without providing clear grounds that Sejong invented Jeongganbo himself. If so, it is necessary to investigate on which grounds it is claimed that Sejong invented Jeongganbo. This paper first examined the grounds of the proposition that "Sejong invented Jeongganbo," which is introduced in the music textbooks for the fifth and sixth grades of elementary school, by separating it into Sejong's creation of Sinak 新樂 (new music), Sejo's invention of Jeongganbo and Sejong's invention of Hangeul. Next, this paper examined how the subject of the invention of Jeongganbo has been described in the textbooks for the fifth and sixth grades in elementary school based on the 2009 revision of music curriculum, and suggested the direction of a desirable music education by pointing out the related problems. According to historical records and circumstances such as Sejong's creation of Sinak, Sejo's invention of Jeongganbo with 16 Jeonggan (square) in one vertical line, Sejong's invention of Hangeul and so on, it seems to be the most reasonable that Sejong is the subject of the invention of Jeongganbo as of now. However, the attitude of the musical academy to accept and educate the unclear thing as if it is a fact does not seem desirable. Therefore, I suggest that it should be described "Jeongganbo was invented in the period of Sejong" or "it is supposed that Jeongganbo was invented by Sejong" rather than presenting "Sejong made Jeongganbo" or "created" until revealing the clear evidence about the subject of Jeongganbo.

• (The) Research of the performance art and culture
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• no.43
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• pp.79-120
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• 2021

Nagyangchun is a Dangak that has been handed down to the present time with Boheoja as a Saak of the Song Dynasty which was introduced in the Goryeo Dynasty. The title and lyrics of Nagyangchun are conveyed in the Dangakjo of Goryeosa-akji and the Jeungbomunheonbigo. The remaining scores containing Nagyangchun include Akjangyoram, Sogagwonbo Vol.4 and Vol.6 of the Joseon Dynasty and Aakbu-akbo, the 6th Aaksaeng-gyogwacheol, Leewangjikaakbu-oseonakbo during the Japanese colonial period. Besides, the current melody of Nagyangchun is based on Hangugeumak and Gugakjeonjib published by the National Gugak Center. This paper aims to examine how Nagyangchun, which is currently being performed at the National Gugak Center, went through the process of change to have the same structure and form as it is now using these scores as a research subject. The study results are summarized as follows. First, the song of Nagyangchun, which was originally Saak but transmitted as an instrumental piece without lyrics, first appeared in the Hangugeumak Vol.16 and Gugakjeonjib Vol.7 published by the National Gugak Center in 1978 and 1979. In this process, the Janggu added by Kim Ki-soo is now disappearing and is replaced by Jwago. Second, though the five notes of 黃, 太, 仲, 林, and 南 have been maintained unchanged since the Akjangyoram, the pitch of 無/應 and 夾/姑, which appear once each, gradually rises and is unified into 應 and 姑 during the period of Aaksaeng-gyogwacheol or at the latest Leewangjikaakbu-oseonakbo, and reached the present. Third, the current melody of Nagyangchun consists of a structure in which the tones and range of each phrase rises within the form of Mijeonsa (a·b·c·d) and Mihusa (e·b'·c'·d'). Particularly, except for the a-type and e-type melodies, which are the introduction for the Mijeonsa and Mihusa, the remaining melodic types show a gradually descending structure within the corresponding phrase, so the structure of ascending and descending is generally in harmony. Forth, the Ganeum that appeared from Aakbu-akbo are currently classified into seven types, and they appear in ascending pitches of 2nd, 3rd, 4th, and 5th and play a role in smoothly or fluently connecting melodic progression. Fifth, after Akjangyoram, Nagyangchun, which had been handed down as an instrumental piece without lyrics, was restored in 1960 by Lee Hye-gu, and is being passed down as the form of male and female vocals added to the instrumental accompaniment. As a result of examining the current Nagyangchun, which was formed through the process of change after Akjangyoram, it was found that there were tasks that required reconsideration of the current Nagyangchun, which is being played at the National Gugak Center, such as the arrangement of Janggu, the identification of the key, and the investigation of the lyrics. When follow-up studies are continued in the future, it will be able to contribute to the cultural transmission of Nagyangchun.

• (The) Research of the performance art and culture
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• no.43
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• pp.325-356
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• 2021

This study is to analyze the current status of transmission and musical characteristics of Naeseo-deulilsori in Changwon, and the purpose of this study is to illuminate the value of deulilsori in Naeseo region, so that it can be continuously inherited. Naeseo-deulsori consists of the Mosimgi-sori, Nonmaegi-sori, and Chingchingi-sori. Mosimgi-sori, which is called when planting a seedling, is divided into 6 types according to the order and situation of work. ① rice planting sound, ② rice planting sound called in the morning, ③ rice planting sound called at lunch time, ④ rice planting sound called after lunch, ⑤ rice planting sound called when it is raining or cloudy, ⑥ rice planting sound called at sunset. Mosimgi-sori, which is called when planting a seedling, is based on Menali-tori, but partly influenced by Yugjabaegi-tori. However, it was typical Menali-tori in the slow The sound of rice planting in the nearby Haman region, but as the speed increased in the fast The sound of rice planting, the characteristics of Menali-tori faded and la↘mi perfect fourth descending frequently appeared. In the sound of rice planting in Goseong, both slow and fast sounds were strongly influenced by Yugjabaegi-tori. In the end, the sound of rice planting in the Naeseo region is less Yugjabaegi-tori than in the Goseong region and stronger than in Haman region. This combination of tori is a musical bargaining phenomenon that appears in the border region, and it can be said to be a geographical and regional characteristic of the Naeseo region. Nonmaegi-sori has the same sound as 'Sangsadeio' throughout the nearby Goseong and Haman regions. However, in Nonmaegi-sori in the Naeseo region, a strong Gyeong-tori tendency is found in the sound received. Looking at the flow of the melody of Nonmaegi-sori, it seems that the pitch has been changed by the intestines in recent years, and this modified melodic form has continued as it is. In order to guarantee locality, this part seems to need to be corrected in the future.