• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.18-24
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• 2012

Purpose : Although lung ventilation SPECT (LV-SPECT) has a good sensitivity in detection of deep lung lesions, it is difficult to apply the LV-SPECT to patients having breathing problems due to limited examination time. In this study, we evaluated the usefulness of LEAP collimator, which provides high detection sensitivity and tolerable resolution, for the LV-SPECT in terms of diagnostic accuracy and examination time. Materials and Methods : Four volunteers inhaled Technegas (370 MBq) and the lung ventilation planar scan (LVPS, 300 counts/view (cpv)) with LEHR collimator was performed using Siemens E.cam scanner as a reference test. LV-SPECT scans were performed with three collimators, LEHR, LEUHR, and LEAP, in low (7 kcpv) and high (70 kcpv) counting modes. The count ratios of left (LT) and right (RT) lung segments were calculated on the geometric mean view of anterior and posterior images for LVPS and on the summed coronal images of LV-SPECT, respectively. Comparing to LVPS, the usefulness of three different collimators for LV-SPECT was evaluated through statistical analysis (paired t-test), on count ratios of lung segments. Results : The average LT:RT ratio in LVPS was 47:53. For LV-SPECT, there were negligible difference of the LT:RT ratios (48:52 on average) among three different collimators in low and high counting modes. Comparing to standard LVPS with LEHR, all LV-SPECTs with different collimators resulted in similar diagnostic accuracy through paired t-test (p>0.05). The scan time in LVPS (6 views) was 17.3 min. For LV-SPECT (128 views) in low counting mode, it took 18.7 (LEUHR), 15.0 (LEHR), and 12.3 min (LEAP), respectively. Conclusion : Comparing to standard LVPS, the LV-SPECT with LEAP in low counting mode provided the comparable diagnostic accuracy in addition to shortened scan time.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.12
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• pp.889-896
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• 2013

Advanced Oxidation Processes (AOP) have been interested for removing micropollutants in water. Most of water treatment plants (WTPs) located along the lower part of Nakdong River have adopted the $O_3/BAC$ process and have interesting in peroxone process a kind of AOP. This study evaluated the removal characteristics of residual hydrogen peroxide ($H_2O_2$) combining with the biofiltration process in the next BAC process when the hydrogen peroxide is applied for the WTP operating $O_3/BAC$ process. In the experiment, changing the temperature and the concentration of $H_2O_2$ of influent, the biofiltration process showed rapidly dropped the biodegradability when the $H_2O_2$ concentration was increased and lowered water temperature while BAC process maintained relatively stable efficiency. The influent fixed at $20^{\circ}C$ and the concentration of $H_2O_2$ at 300 mg/L was continuously input for 78 hours. Most of the $H_2O_2$ in the influent did not remove at the biofiltration process controlled 5 to 15 minutes EBCT condition after 24~71 hours operating time while BAC process controlled 5 to 15 minutes EBCT showed 38~91% removal efficiency condition after 78 hours operating time. Besides, after 78 hours continuously input experiment, the biomass and activity of attached bacterial on the biofilter and BAC were $6.0{\times}10^4CFU/g$, $0.54mg{\cdot}C/m^3{\cdot}hr$ and $0.4{\times}10^8CFU/g$, $1.42mg{\cdot}C/m^3{\cdot}hr$ respectively. These biomass and activity values were decreased 99% and 72% in biofilter and 68% and 53% in BAC compared with initial condition. The biodegradation rate constant ($k_{bio}$) and half-life ($t_{1/2}$) in BAC were decreased from $1.173min^{-1}$ to $0.183min^{-1}$ and 0.591 min to 3.787 min respectively according to increasing the $H_2O_2$ concentration from 10 mg/L to 300 mg/L at $5^{\circ}C$ water temperature and the $k_{bio}$ and $t_{1/2}$ were $1.510min^{-1}$ to $0.498min^{-1}$ and 0.459 min to 1.392 min at $25^{\circ}C$ water temperature. By increasing the water temperature from $5^{\circ}C$ to $15^{\circ}C$ or $25^{\circ}C$, the $k_{bio}$ were increased 1.1~2.1 times and 1.3~4.4 times. If a water treatment plant operating $O_3/BAC$ process is considering the hydrogen peroxide for the peroxone process, post BAC could effectively decrease the residual $H_2O_2$, moreover, in case of spilling the $H_2O_2$ into the water process line, these spilled $H_2O_2$ concentration can be able to decrease by increasing the EBCT at the BAC process.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.4
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• pp.218-227
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• 2006

Purpose: The HSV1-tk reporter gene system is the most widely used system because of its advantage that direct monitoring is possible without the introduction of a separate reporter gene in case of HSV1-tk suicide gene therapy. In this study, we investigate the usefulness of the reporter probe (substrate), $9-(4-[^{18}F]Fluoro-3-hydroxymethylbutyl)$guanine ($[^{18}F]FHBG$) for non-invasive reporter gene imaging using PET in HSV1-tk expressing hepatoma model. Materials and Methods: Radiolabeled FHBG was prepared in 8 steps from a commercially available triester. The labeling reaction was carried out by NCA nucleophilic substitution with $K[^{18}F]/K2.2.2.$ in acetonitrile using N2-monomethoxytrityl-9-14-(tosyl)-3-monomethoxytritylmethylbutyl]guanine as a precursor, followed by deprotection with 1 N HCl. Preliminary biological properties of the probe were evaluated with MCA cells and MCA-tk cells transduced with HSV1-tk reporter gene. In vitro uptake and release-out studies of $[^{18}F]FHBG$ were performed, and was analyzed correlation between $[^{18}F]FHBG$ uptake ratio according to increasing numeric count of MCA-tk cells and degree of gene expression. MicroPET scan image was obtained with MCA and MCA-tk tumor bearing Balb/c-nude mouse model. Results: $[^{18}F]FHBG$ was purified by reverse phase semi-HPLC system and collected at around 16-18 min. Radiothemical yield was about 20-25%) (corrected for decay), radiochemical purity was >95% and specific activity was around >55.5 $GBq/{\mu}\;mol$. Specific accumulation of $[^{18}F]FHBG$ was observed in HSV1-tk gene transduced MCA-tk cells but not in MCA cells, and consecutive 1 hour release-out results showed more than 86% of uptaked $[^{18}F]FHBG$ was retained inside of cells. The uptake of $[^{18}F]FHBG$ was showed a highly significant linear correlation ($R^2=0.995$) with increasing percentage of MCA-tk numeric cell count. In microPET scan images, remarkable difference of accumulation was observed for the two type of tumors. Conclusion: $[^{18}F]FHBG$ appears to be a useful as non-invasive PET imaging substrate in HSV1-tk expressing hepatoma model.

• Journal of radiological science and technology
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• v.33 no.1
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• pp.37-44
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• 2010

We sought to confirm an independent factor about in-stent restenosis (ISR) in the patients who underwent drug-eluting stent (DES) and know a possibility as a predictor of measured coronary artery calcium score by MDCT. A total of 178 patients (159 men, $61.7{\pm}10.0$ years of age) with 190 coronary artery lesions were included in this study out of 1,131 patients who underwent percutaneous coronary intervention (PCI) with DES implantation for significant stenosis on MDCT at Chonnam National University Hospital between May 2006 and May 2009. All lesions were divided into two groups with the presence of ISR : group I (re ISR, N = 57) and group II (no ISR, N = 133). Compared to group II, group I was more likely to be older ($65.8{\pm}9.0$ vs. $60.2{\pm}9.9$ years, p = 0.0001), diabetic (21.8% vs. 52.6%, p = 0.0001), have old myocardial infarction (8.8% vs. 2.3%, p = 0.040), left main stem disease (5.3% vs. 0.8%, p = 0.047), and smaller stent size ($3.1{\pm}0.3\;mm$ vs. $3.3{\pm}0.4\;mm$, p = 0.004). Group II was more likely to be smokers (19.3% vs. 42.1%, p = 0.003), have dyslipidemia (8.8% vs. 23.3%, p = 0.019). Left ventricular ejection fraction, lesion complexity, and stent length were not different between the two groups. Total CAC score was $389.3{\pm}458.3$ in group I and $371.2{\pm}500.8$ in group II (p = 0.185). No statistical difference was observed between the groups in CAC score in the culprit vessel, left main stem, left anterior descending artery, left circumflex artery, and right coronary artery. On multivariate logistic regression analysis, left main stem disease (OR = 168.0, 95% CI = 7.83-3,604.3, p = 0.001), male sex (OR = 36.5, 95% CI = 5.89-2,226.9, p = 0.0001), and the presence of diabetes (OR = 2.62, 95% CI = 1.071-6.450, p = 0.035) were independent predictors of ISR after DES implantation. In patients who underwent DES implantation for significant coronary stenosis on MDCT, ISR was associated with left main stem disease, male sex, and the presence of diabetes. However, CAC score by MDCT was not a predictor of ISR in this study population.

• Radiation Oncology Journal
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• v.20 no.4
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• pp.343-352
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• 2002

Purpose : Radiotherapy is the main treatment modality for uterine cervix cancer. Since the rectum is in the radiation target volume, rectal bleeding is a common late side effect. This study evaluates the risk factors of radiation induced rectal bleeding and discusses its optimal management. Materials and Methods : total of 213 patients who completed external beam radiation therapy (EBRT) and intracavitary radiation (ICR) between September 1994 and December 1999 were included in this study. No patient had undergone concurrent chemo-radiotherapy. Ninety patients received radiotherapy according to a modified hyperfractionated schedule. A midline block was placed at a pelvic dose of between 30.6 Gy to 39.6 Gy. The total parametrial dose from the EBRT was 51 to 59 Gy depending on the extent of their disease. The Point A dose from the HDR brachytherapy was 28 Gy to 30 Gy $(4\;Gy\times7,\;or\;5\;Gy\times6)$. The rectal point dose was calculated either by the ICRU 38 guideline, or by anterior rectal wall point seen on radiographs, with barium contrast. Rectal bleeding was scored by the LENT/SOMA criteria. For the management of rectal bleeding, we opted for observation, sucralfate enema or coagulation based on the frequency or amount of bleeding. The median follow-up period was 39 months $(12\~86\;months)$. Results : The incidence of rectal bleeding was $12.7\%$ (27/213); graded as 1 in 9 patients, grade 2 in 16 and grade 3 in 2. The overall moderate and severe rectal complication rate was $8.5\%$. Most complications $(92.6\%)$ developed within 2 years following completion of radiotherapy (median 16 months). No patient progressed to rectal fistula or obstruction during the follow-up period. In the univariate analysis, three factors correlated with a high incidence of bleeding an icruCRBED greater than 100 Gy $(19.7\%\;vs.\;4.2\%)$, an EBRT dose to the parametrium over 55 Gy $(22.1\%\;vs.\;5.1\%)$ and higher stages of III and IV $(31.8\%\;vs.\;10.5\%)$. In the multivariate analysis, the icruCRBED was the only significant factor (p>0.0432). The total parametrial dose from the EBRT had borderline significance (p=0.0546). Grade 1 bleeding was controlled without further management (3 patients), or with sucralfate enema 1 to 2 months after treatment. For grade 2 bleeding, sucralfate enema for 1 to 2 months reduced the frequency or amount of bleeding but for residual bleeding, additional coagulation was peformed, where immediate cessation of bleeding was achieved (symptom duration of 3 to 10 months). Grade 3 bleeding lasted for 1 year even with multiple transfusions and coagulations. Conclusion : Moderate and several rectal bleeding occurred in $8.5\%$ of patients, which is comparable with other reports. The most significant risk factor for rectal bleeding was the accumulated dose to the rectum (icruCRBED), which corrected with consideration to biological equivalence. Prompt management of rectal bleeding, with a combination of sucralfate enema and coagulation, reduced the duration of the symptom, and minimized the anxiety/discomfort of patients.

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.1
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• pp.19-28
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• 2020

This study was conducted to compare the agronomic characteristics and productivity according to the species and varieties of winter forage crops in reclaimed land. Winter forage crops used in this study were developed in National Institute of Crop Science, RDA. Oats ('Samhan', 'Jopung', 'Taehan', 'Dakyung' and 'Hi-early'), forage barley ('Yeongyang', 'Yuyeon', 'Yujin', 'Dacheng' and 'Yeonho'), rye ('Gogu', 'Jogreen' and 'Daegokgreen') and triticale ('Shinyoung', 'Saeyoung', 'Choyoung', 'Sinseong', 'Minpung' and 'Gwangyoung') were planted in the reclaimed land of Sihwa district in Hwaseong, Gyeonggi-do in the autumn of 2018 and cultivated using each standard cultivation method, and harvested in May 2019(oat and rye: 8 May, barley and triticale: 20 May.) The emergency rate was the lowest in rye (84.4%), and forage barley, oat and triticale were in similar levels (92.8 to 98.8%). Triticale was the lowest (416 tiller/㎡) and oat was the highest (603 tiller/㎡) in tiller number. Rye was the earliest in the heading date (April 21), triticale was April 26, and oat and forage barley were in early May (May 2 and May 5). The plant height was the highest in rye (95.6 cm), and triticale and forage barley was similar (76.3 and 68.3cm) and oat was the lowest (54.2 cm). Dry matter(DM) content of rye was the highest in the average of 46.04% and the others were similar at 35.09~37.54%. Productivity was different among species and varieties, with the highest dry matter yield of forage barley (4,344 kg/ha), oat was similar to barley, and rye and triticale were lowest. 'Dakyoung' and 'Hi-early' were higher in DM yield (4,283 and 5,490 kg/ha), and forage barley were higher in 'Yeonho', 'Yujin' and 'Dacheng' varieties (4,888, 5,433 and 5,582 kg/ha). Crude protein content of oat (6.58%) tended to be the highest, and TDN(total digectible nutrient) content (63.61%) was higher than other varieties. In the RFV(relative feed value), oats averaged 119, while the other three species averaged 92~105. The weight of 1,000 grain was the highest in triticale (43.03 g) and the lowest in rye (31.61 g). In the evaluation of germination rate according to the salt concentration (salinity), the germination rate was maintained at about 80% from 0.2 to 0.4% salinity. The correlation coefficient between germination and salt concentration was high in oat and barley (-0.91 and -0.92) and lowest in rye (-0.66). In conclusion, forage barley and oats showed good productivity in reclaimed land. Adaptability is also different among varieties of forage crops. When growing forage crops in reclaimed land, the selection of highly adaptable species and varieties was recommended.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.108-118
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• 2009

Statement of problem: Volume stability, microstructure reproducibility and fluidity along with compatibility with dental stone must be in consideration in order to use tissue conditioner as a material for functional impression. There are few studies concerning the influence of time factor in oral condition on surface roughness of the stone and optimal retention period in the oral cavity considering such changes in surface roughness. Purpose: The purpose of this study was to find out the influence of various kinds of tissue conditioner, its powder/liquid ratio and immersion time on surface roughness of the stone. Material and methods: Materials used in this study were the three kinds of tissue conditioners(Coe-Comfort, Visco-Gel, Soft-Liner) and were grouped into three: group R-mixed with standard powder/liquid ratio that was recommended by the manufacturers, group M-mixed with 20% more powder, group L-mixed with 20% less powder. Specimens were made with the size of 20 mm diameter and 2 mm width. Each tissue conditioner specimens were subdivided into 5 groups according to the immersion time(0 hour, 1 day, 3 days, 5 days, 7 days), completely immersed into artificial saliva and were stored under $37^{\circ}C$. Specimens of which the given immersion time elapsed were taken out and were poured with improved stone, making the stone specimens. Surface roughness of the stone specimens was measured by a profilometer. Results: Within the limitation of this study, the following results were drawn. 1. Major influencing factor on surface roughness of the stone model made from tissue conditioner was the retention period(contribution ratio($\rho$)=62.86%, P<.05) of the tissue conditioner in oral cavity to make functional impression. 2. In case of Coe-Comfort, higher mean surface roughness value of the stone model with statistical significance was observed compared to that of Soft-Liner and Visco-Gel as immersion time changes(P<.05). 3. In case of group L(less), higher mean surface roughness value of the stone model with statistical significance was observed compared to that of R(recommended) and M(more) group as immersion time changes(P<.05). Conclusion: We may conclude that as the retention period of time in oral cavity influences surface roughness of the stone model the most and as the kind of tissue conditioner and its P/L ratio may influence also, clinician should well understand the optimal retention period in oral cavity and choose the right tissue conditioner for the functional impression, thus making the functional impression with tissue conditioner usefully.

• Journal of Chest Surgery
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• v.39 no.4 s.261
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• pp.289-297
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• 2006

Background: Surgery for Stanford type A aortic dissection shows a high operative mortality rate and frequent postoperative brain injury. This study was designed to find out the risk factors leading to operative mortality and brain injury after surgical repair in patients with type A aortic dissection. Material and Method: One hundred and eleven patients with type A aortic dissection who underwent surgical repair between February, 1995 and January 2005 were reviewed retrospectively. There were 99 acute dissections and 12 chronic dissections. Univariate and multivariate analysis were performed to identify risk factors of operative mortality and brain injury. Resuit: Hospital mortality occurred in 6 patients (5.4%). Permanent neurologic deficit occurred in 8 patients (7.2%) and transient neurologic deficit in 4 (3.6%). Overall 1, 5, 7 year survival rate was 94.4, 86.3, and 81.5%, respectively. Univariate analysis revealed 4 risk factors to be statistically significant as predictors of mortality: previous chronic type III dissection, emergency operation, intimal tear in aortic arch, and deep hypothemic circulatory arrest (DHCA) for more than 45 minutes. Multivariate analysis revealed previous chronic type III aortic dissection (odds ratio (OR) 52.2), and DHCA for more than 45 minutes (OR 12.0) as risk factors of operative mortality. Pathological obesity (OR 12.9) and total arch replacement (OR 8.5) were statistically significant risk factors of brain injury in multivariate analysis. Conclusion: The result of surgical repair for Stanford type A aortic dissection was good when we took into account the mortality rate, the incidence of neurologic injury, and the long-term survival rate. Surgery of type A aortic dissection in patients with a history of chronic type III dissection may increase the risk of operative mortality. Special care should be taken and efforts to reduce the hypothermic circulatory arrest time should alway: be kept in mind. Surgeons who are planning to operate on patients with pathological obesity, or total arch replacement should be seriously consider for there is a higher risk of brain injury.

• Journal of Korean Society of Forest Science
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• v.12 no.1
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• pp.31-43
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• 1971

In order to examine the taxonomic difference between the type of Pinus parviflora S. et Z. native to the Dagelet Island and the type of the species introduced to a number of places of the inland of South Korea, investigations on principal characters of needle, cone and seed were made with a hope to obtain informations on the evaluation of the species for possible use in the reforestation program in Korea in the future. Pinus parviflora is belonged to the Sub-genus Haploxylon of Genus Pinus and it has been speculated among dendrologists that this speoies is not monotypic. 308 rendomly selected trees from 8 different elevations of a natural stand of P. parviflora in the Dagelet Island, and 168 trees of P. parviflora growing at 15 different locations of the inland of South Korea were employed as samples along with 300 trees of P. koraiensis as control. The results obtained are summarized as follows: 1. The needle length of the Pinus parviflora of the Dagelet Island is longer than that of the species growing in the inland by 21-35 percent with statistical significancy. (Table 2) 2. In the cross section of needle, no resin canal was observed in about 50-70 percent of the sample trees of the Dagelet Island, whereas the resin canals appearing at external in most cases were observed in all sample trees from the inland. Consequently, the number of resin canals per needle was 0.4-0.9 with the Dagelet Island type and 2.0-2.7 with the inland type and these differences were statistically significant. (Table 3, Fig.2) 3. The Pinus parvviflora type of the Dagelet Island bas yellowish brown cones, and the Pinus parviflora type of Suwon and Kwangyang has redish brown cones. In both the length of cone and the number of cone scale, the difference between the type of the Dagelet Island and the type of the inland was also statistically significant. The cone scales of the Dagelet Island type are slightly opened, whereas the cone scales are widely opened with both of Suwon and Kwangyang type. (Table 4, Fig. 3) 4. the seed color, of the Dagelet Island type is yellowish brown, while it is greyish brown with Kwangyang and Suwon type. In the length and width of seed, the Dagelet Island type showed significantly larger values than that of the inland type. The length of seed was longest with the Kwangyang type being followed by Suwon and the Dagelet Island type in ordar. The seed wing of the Kwangyang type are longer than the seed, while that of the Dagelet Island type is degenerated to be shorter than the seed. (Table 5, Fig. 4) 5. The Pinus parviflora type of the Dagelat Island is similar in many respects to the southern type of Pinus parviflora of Japan except that many has no resin canals in the needle. 6. On the basis of the results obtained in this study, it may be concluded that the type of Pinus parviflora of the Dagelet Island is significantly different from the type of the species introduced to the inland and that there is no recognizable variation between the population of the different altitude of the Dagelet Island and the individual variation within population is also negligible. In the light of the high value of the tree not only as an ornamental tree but as an economical tree, The type of Pinus parviflora of the Dagelet Island is considered to be recommendable to be used for the future reforestation program of Korea.

• Korean Journal of Heritage: History & Science
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• v.53 no.4
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• pp.150-169
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• 2020

Surveys of Buddhist ruins at Namsan in Gyeongju began in earnest during the Japanese colonial era, undertaken by Japanese scholars. These surveys of Buddhist remains in Namsan made during the colonial period should be seen as previous research which cannot be ignored in any in-depth study of Buddhist ruins in Gyeongju. Full-scale surveys of Buddhist ruins at Namsan began in the 1920s. Previous surveys conducted around the time of the Japanese annexation of Korea in 1910 are generally viewed as only representing preliminary investigations and, thus, have not received much attention. However, these early surveys are significant in that they led to the Buddhist ruins on Namsan becoming widely known in the 1910s and served as the foundations for later studies. The removal of the Seated Medicine Buddha from Samneung Valley in Gyeongju in 1915 and its subsequent exhibition at the Joseon Local Products Expo, which marked the fifth anniversary of the Japanese administration of Korea, was especially important in garnering attention for Namsan's wealth of Buddhist artifacts, as the statue was placed in the main hall of the art museum and attracted a great deal of interest from visitors. It is typically thought that this Seated Medicine Buddha was exhibited in 1915 because it was the most beautiful and well-preserved statue from Namsan. However, the removal of this statue was closely related to the proposed move of the Seokguram statue to Seoul around the time of Korea's annexation. The plan to move Seokguram to Seoul was primarily devised by Terauchi Masatake, and the plan, based on Ilseontongjo-ron ('日鮮同祖論'), a historical theory that prehistoric Korean and Japanese people were of the same blood, and Joseon Jeongcheasoeng-ron ('朝鮮停滯性論'), a historical theory arguing that development had stagnated in Korea, was intended to be a visual demonstration of a new era for Korea. This new era was to proceed under the rule of the Japanese Empire through the dissolution of Gyeongbokgung, the symbol of the Joseon Dynasty, which would be replaced with past glories as symbolized by the statue of Buddha. However, as the plan floundered, the replacement for Seokguram in Seoul ended up being none other than the Seated Medicine Buddha of Samneung Valley. Surveys of the Seated Medicine Buddha began in 1911, administered by Sekino Tadashi, but he likely learned of the statue's location from Moroga Hideo or Kodaira Ryozo, Japanese residents of Gyeongju. It is also probable that these Japanese residents received a request from the Japanese Government General of Korea to find a Buddha statue that was worthy of being displayed at exhibitions. In this way, we can say that the transfer of the Seated Medicine Buddha to Seoul was the result of close cooperation between the Government General, Sekino Tadashi, and Japanese residents of Gyeongju. This also had the effect of removing the magical veil which had shrouded the Buddhist ruins of Namsan. In other words, while the early surveys of Buddhist ruins on Namsan are significant, it is difficult to argue that the surveys were undertaken for purely academic purposes, as they were deeply related to the imperial ambitions of Governor-General Terauchi which encompassed the plans to move Seokguram to Seoul and the successful hosting of the 1915 Expo. It should also be pointed out that the failure of the plan to move Seokguram to Seoul and the preservation of the Seated Stone Buddha of Mireuggok at Namsan was in no small part due to resistance from Korean residents in Gyeongju. Although it is not described in detail in the paper, research is needed which shows that the Korean residents of Gyeongju were not simple bystanders, but agents of history.