• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.4
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• pp.1-10
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• 2011

This study was conducted to compare the growth of Zoysia japonica depending on different soil treatments in Saemangeum sea dike, which is filled with dredged soil. Zoysia japonica was planted using sod-pitching method on the control plot. On plots which were treated with forest soil and soil improvement, Zoysia japonica seeds were sprayed mechanically. Sixteen months after planting, coverage rate, leaf length, leaf width, and root length were measured and analyzed. Also, three Zoysia japonica samples per plot were collected to analyze nutrient contents. Coverage rate was 100% in B treatment plot(dredged soil+$40kg/m^3$ soil improvement+forest soil), in C treatment plots (dredged soil+$60kg/m^3$ soil improvement+forest soil), and D treatment plots (dredged soil+$60kg/m^3$ soil improvement), while only 43% of the soil surface was covered with Zoysia japonica on control plots. The width of the leaf on C treatment plots (3.79mm) was the highest followed by D treatment (3.49mm), B treatment (2.40mm) and control plots (1.97mm). Leaf and root length of D treatment was 30.18cm and 13.18cm, which were highest among different treatments. The leaf length of D treatment was highest followed by C, B, and A treatments. The root length of D treatment was highest followed by C, A, and B treatments. The nitrogen and phosphate contents of the above ground part of Zoysia japonica were highest in C treatment, followed by D, B, and A treatments. The nitrogen and phosphate contents of the underground part of Zoysia japonica were highest in D treatment, followed by C, A, and B treatments. C and D treatments showed the best results in every aspect of grass growth. The results of this study could be used to identify the cost effective way to improve soil quality for soil surface fixation on reclaimed areas using grass species.

• The Korean Journal of Nuclear Medicine
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• v.36 no.4
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• pp.244-254
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• 2002

Purpose: This study investigated the differences between technetium-99m ethyl cysteinate dimer (Tc-99m ECD) and technetium-99m hexamethylpropylene amine oxime (Tc-99m HMPAO) uptake in the normal brain by means of statistical parametric mapping (SPM) analysis. Materials and Methods: We retrospectively analyzed age and sex matched 53 cases of normal brain SPECT. Thirty-two cases were obtained with Tc-99m ECD and 21 cases with Tc-99m HMPAO. There were no abnormal findings on brain MRIs. All of the SPECT images were spatially transformed to standard space, smoothed and globally normalized. The differences between the Tc-99m ECD and Tc-99m HMPAO SPECT images were statistically analyzed using statistical parametric mapping (SPM'99) software. The differences bgetween the two groups were considered significant ant a threshold of corrected P values less than 0.05. Results: SPM analysis revealed significantly different uptakes of Tc-99m ECD and Tc-99m HMPAO in the normal brains. On the Tc-99m ECD SPECT images, relatively higher uptake was observed in the frontal, parietal and occipital lobes, in the basal ganglia and thalamus, and in the superior region of the cerebellum. On the Tc-99m HMPAO SPECT images, relatively higher uptakes was observed in subcortical areas of the frontal region, temporal lobe, and posterior portion of inferior cerebellum. Conclusion: Uptake of Tc-99m ECD and Tc-99m HMPO in the normallooking brain was significantly different on SPM analysis. The selective use of Tc-99m ECD of Tc-99m HMPAO in brain SPECT imaging appears especially valuable for the interpretation of cerebral perfusion. Further investigation is necessary to determine which tracer is more accurate for diagnosing different clinical conditions.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.1
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• pp.17-23
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• 1976

In order to investigate the fate of nitrogen in the paddy soil, Suchang, Hwasoon and Susan soil which have different properties, were treated with several nitrogen fertilizers such as ammonium chloride, ammonium sulfate, urea and SCU (sulfur-coated urea), and incubated under water-logged condition in $30^{\circ}C$ incubator. $NH_4-N$, $NO_3-N$, $Fe^{++}$ and pH in soil and stagnant water, were determined at 10, 20, 30, 40 and 50 days after incubation. The obtained results were summarized as follows: 1. The effect of rising temperature was increased in order of Hwasoon>Suchang>Susan and the effect of air drying soil was risen in order of Susan>Hwasoon>Suchang, while the rate of ammonication was in order of Susan>Suchang>Hwasoon. 2. The changes of $NH_4-N$ in stagnant water was dependent upon the nitrogen concentration of $NH_4Cl$ and $(NH_4)SO_4$ plat was high and decreased after 30 days incubation, but increased after 40 days and then decreased again. In contrast with the above, $NH_4-N$ concentration of urea and SCU plot was low but the change showed slightly through the incubation period. 3. Accumulation of $NH_4-N$ in the oxidative layer of the $NH_4Cl$ and $(NH_4)_2SO_4$ plot was higher than that of urea and SCU plot and $NH_4-N$ content was decreased with the incubation period. The change of $NH_4-N$ in the reductive layer showed the same pattern. 4. The changes of $NO_3-N$ in the stagnant water were different according to soil properties and nitrogen fertilizer. $NO_3-N$ concentration in stagnant water of urea and SCU plot was higher than in the $NH_4-Cl$ $(NH_4)_2SO_4$ plot and nearly disappeared after 30 to 40 days incubation. 5. The $NO_3-N$ concentration in the oxidative layer of soil was higher than reductive layer. The pattern of change was different in accordance with soil properties and nitrogen fertilizers. In general, nitrification in urea and SCU plot was more increased than $(NH_4)_2SO_4$ plot. In reductive layer, the concentration of $NO_3-N$ was very low until 30 days incubation and thereafter increased slightly. 6. Upon the concentration of $NH_4-N$ and $NO_3-N$ in stagnant water and soil, it was assumed that denitification of urea and SCU plot was higher than $NH_4Cl$ and $(NH_4)_2SO_4$ plot and denitrified nitrogen in incubation period was above 50%.

• Korean Journal of Heritage: History & Science
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• v.51 no.2
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• pp.170-203
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• 2018

From the period of Japanese colonialism up to the present, the researchers of archaeology and ancient history in Korea and Japan have paid much attention to the Honam area. Recently the ruins and relics of Wae lineage are often discovered at archaeological excavation sites in this region. In particular, at least 17 keyhole-shaped mounds were confirmed. The fact that three mounds were built on one site was newly revealed. Haniwa, a representative earthenware object of the Kofun period in Japan, was discovered as well. Therefore, the study of a historical meaning of archaeological materials about Wae lineage in the Honam area thus far must be reexamined. The ruins and relics of Wae lineage in the Honam area have been studied by selecting only specific cases. I identified all the ruins and relics of Wae lineage in the Honam area and analyzed the process of their change in this paper. I reviewed the relationship between Wae and Mahan, and the purpose of their negotiation based on archaeological characteristics, changing processes, and historical records on a quarterly basis. The ruins and relics of Wae lineage have increased and widely spread since the early period of the 5th century in the Honam area. This tendency continued until the late period of the 6th century. Weapons of Wae lineage were introduced and tombs in the style of Wae were built from the late 4th century to the early period of the 5th century (TG232~TK216 period). Sueki was introduced from the middle to late period of the 5th century (TK208~TK23 period). Keyhole-shaped mounds and tombs in the style of Wae were built from the late period of the 5th century to the early period of the 6th century (TK47~MT15 period). Japanese weapons were introduced from the middle to late period of the 6th century (TK10~TK209 period). In other words, the archaeological appearance is different in each quarterly period. There was an intensive diplomatic relationship between Baekje and Wae in the TG232~TK216 period. The military might be included in a mission of Wae. The materials of Wae lineage of this period are likely to be related to this. Sueki spread to the inland part of the Honam area in the TK208~TK23 period. This Sueki tends to be excavated on advantageous sites for the accumulation and distribution of supplies. The main characters of the keyhole-shaped mounds are presumed to be a group of traders which were under the control of a certain influence in the north of Kyushu. The keyhole-shaped mounds were abruptly built at some distance from mounds of the leaders in the Honam area. Additionally, there was no special influence base to which the characters of the keyhole-shaped mounds belonged in the surroundings. However, it might have been impossible for the group of traders to build the keyhole-shaped mounds without the support from the residents at all because there was a big difference in the building technology of the keyhole-shaped mounds between Japan and the Honam area. The time of building some keyhole-shaped mounds is the same or almost the same with that of the mounds built for the regional leaders. This proves a close relationship with the residents as well. What do the archaeological materials of Wae lineage which have been used and buried mean over 200 years in the Honam area? Geumgwan Gaya, which had exported iron resources to Japan, perished in the early period of the 5th century. Instead of Gaya, the Honam area might have played an important role to supply the necessary resources to Japan. We assume that the Japanese (Wae) actively worked to acquire various resources focusing on the underground resources in the Honam area.

• Korean Journal of Heritage: History & Science
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• v.56 no.4
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• pp.72-92
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• 2023

As described above, the location of Jagiso eunchon in Goheung-hyeon and the nature of Undae-ri kiln site were examined. Goheung-hyeon's administrative agency was moved to Joyang-hyeon, which is now Joseong-myeon, Boseong-gun in 1395. Therefore, Goheung-hyeon Jagiso Eunchon in Sejongsillok Jiriji corresponding to 1424~1432 should be found in the west of Joseong-myeon, Boseong, where the administrative agency was moved in 1395. Among the four boundaries of Goheung-hyeon recorded in the 『Sejongsillok』 Jiriji, it is recorded as 2-ri by the sea in the south and 8-ri by Nakan in the east. If the current Goheung-hyeon is Goheung-hyeon's administrative agency in the Sejongsillok Jiriji Records Compilation Period, it cannot be the boundary the south and east mentioned above. This is because it cannot be 2-ri from the current Goheung-eup to the sea in the south, and Nakan is close to the north, not the east, as recorded. However, it has already been suggested that Joyanghyeonseong(朝陽縣城), located in Gonae Village, Ucheon-ri, Josung-myeon, Boseonggun is an Goheunghyeon's administrative agency. And if the four-way boundary of Goheung-hyeon was converted into the current distance unit based on this place(Joyanghyeonseong, 朝陽縣城), an approximate result could be obtained even if it did not exactly match. Therefore, it is highly likely that Goheung-hyeon's administrative agency, which was moved to Joyang-hyeon, Boseong in 1395, is Gonae Village, Ucheon-ri, JoSeong-myeon, Boseong. Jagiso eunchon(犾村) in Goheung-hyeon can be interpreted as a "dog-shouting village." It is thought to be a meaning structure of "animal + sound". A place name thought to have the same structure was identified in Jeongheung-ri, west of Ucheon-ri, Joseongmyeon, Boseong. It is the name of a village called Hoeum-dong(虎吟洞), and it is interpreted as the sound of a tiger or the bark of a tiger, which is the same as the meaning structure of Eunchon. However, there is Gaesan Village in the south of Hoeum-dong, and a Buncheong ware kiln site was identified around it. At this kiln site, a fragment of carved Buncheong ware engraved with the character "Eon", which corresponds to the right stroke of the character "Seom (贍)" in the name "Naeseom (內贍)" was identified. A small amount of Buncheong ware and Joseon celadon pieces were also identified. It can be seen that the Buncheong ware paid to the government was made by checking the Buncheong ware with the government name engraved on it. On the west side of Joyanghyeonseong Fortress in Ucheon-ri, joseong-myeon, Boseong, which was the administrative agency of Goheung-hyeon and the area around the Gaesan Buncheong ware kiln site in Jeongheung-ri, where the Buncheong ware paid to the government was, is thought to be Jagiso Eunchon, Goheung-hyeon. Jagiso and Dogiso are located in the four directions based on the administrative agency. Naturally, the location of Jagiso and Dogiso is also determined on where the administrative agency of Hyeon is. Since the Goheung-hyeon's administrative agency in the early Joseon Dynasty was moved to Ucheon-ri, joseong-myeon, Boseong-myeon, it is necessary to naturally find Jagiso and Dogiso in Boseong. In addition, regarding the nature of the kiln site in Undae-ri, the aspects of the excavated relics were considered. As a result, it is believed that the Undae-ri kiln site functioned as a jagiso in Heungyang-hyeon from February 1441 to the 1470s. If so, the "Ye" Buncheong ware, which was collected around Undae-ri kiln No. 7, could be naturally understood.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.1
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• pp.32-36
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• 2016

Purpose In nuclear medicine examination, $^{131}I$ is widely used in nuclear medicine examination such as diagnosis, treatment, and others of thyroid cancer and other diseases. $^{131}I$ conducts examination and treatment through emission of ${\gamma}$ ray and ${\beta}^-$ ray. Since $^{131}I$ (364 keV) contains more energy compared to $^{99m}Tc$ (140 keV) although it displays high integrated rate and enables quick discharge through kidney, the objective of this study lies in comparing the difference in exposure dose of $^{131}I$ before and after wearing apron when handling $^{131}I$ with focus on 3 elements of external exposure protection that are distance, time, and shield in order to reduce the exposure to technicians in comparison with $^{99m}Tc$ during the handling and administration process. When wearing apron (in general, Pb 0.5 mm), $^{99m}Tc$ presents shield of over 90% but shielding effect of $^{131}I$ is relatively low as it is of high energy and there may be even more exposure due to influence of scattered ray (secondary) and bremsstrahlung in case of high dose. However, there is no special report or guideline for low dose (74 MBq) high energy thus quantitative analysis on exposure dose of technicians will be conducted based on apron wearing during the handling of $^{131}I$. Materials and Methods With patients who visited Department of Nuclear Medicine of our hospital for low dose $^{131}I$ administration for thyroid cancer and diagnosis for 7 months from Jun 2014 to Dec 2014 as its subject, total 6 pieces of TLD was attached to interior and exterior of apron placed on thyroid, chest, and testicle from preparation to administration. Then, radiation exposure dose from $^{131}I$ examination to administration was measured. Total procedure time was set as within 5 min per person including 3 min of explanation, 1 min of distribution, and 1 min of administration. In regards to TLD location selection, chest at which exposure dose is generally measured and thyroid and testicle with high sensitivity were selected. For preparation, 74 MBq of $^{131}I$ shall be distributed with the use of $2m{\ell}$ syringe and then it shall be distributed after making it into dose of $2m{\ell}$ though dilution with normal saline. When distributing $^{131}I$ and administering it to the patient, $100m{\ell}$ of water shall be put into a cup, distributed $^{131}I$ shall be diluted, and then oral administration to patients shall be conducted with the distance of 1m from the patient. The process of withdrawing $2m{\ell}$ syringe and cup used for oral administration was conducted while wearing apron and TLD. Apron and TLD were stored at storage room without influence of radiation exposure and the exposure dose was measured with request to Seoul Radiology Services. Results With the result of monthly accumulated exposure dose of TLD worn inside and outside of apron placed on thyroid, chest, and testicle during low dose $^{131}I$ examination during the research period divided by number of people, statistics processing was conducted with Wilcoxon Signed Rank Test using SPSS Version. 12.0K. As a result, it was revealed that there was no significant difference since all of thyroid (p = 0.345), chest (p = 0.686), and testicle (p = 0.715) were presented to be p > 0.05. Also, when converting the change in total exposure dose during research period into percentage, it was revealed to be -23.5%, -8.3%, and 19.0% for thyroid, chest, and testicle respectively. Conclusion As a result of conducting Wilcoxon Signed Rank Test, it was revealed that there is no statistically significant difference (p > 0.05). Also, in case of calculating shielding rate with accumulate exposure dose during 7 months, it was revealed that there is irregular change in exposure dose for inside and outside of apron. Although the degree of change seems to be high when it is expressed in percentage, it cannot be considered a big change since the unit of accumulated exposure dose is in decimal points. Therefore, regardless of wearing apron during high energy low dose $^{131}I$ administration, placing certain distance and terminating the administration as soon as possible would be of great assistance in reducing the exposure dose. Although this study restricted $^{131}I$ administration time to be within 5 min per person and distance for oral administration to be 1m, there was a shortcoming to acquire accurate result as there was insufficient number of N for statistics and it could be processed only through non-parametric method. Also, exposure dose per person during lose dose $^{131}I$ administration was measured with accumulated exposure dose using TLD rather than through direct-reading exposure dose thus more accurate result could be acquired when measurement is conducted using electronic dosimeter and pocket dosimeter.

• Journal of Fisheries and Marine Sciences Education
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• v.4 no.1
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• pp.30-46
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• 1992

Korea's first exploratory tuna fishing was done with a used longliner in 1957. Then the commercial fishing has been made steady headway since the 1960's and grown up to one of major tuna fishing countries in 1970's. The tuna fishing aimed primarily at acquiring foreign currency, then tuna was exported directly from the overseas fishing base. Tuna, however, has been gradually favored by Koreans as high-proteined foods according to the growth of GNP since the 1970's. In 1980, the canned tuna began to be produced and sold at home. And so the demand of raw tuna for cannaries has steeply increased not only for home but also for abroad, and stimulated the development of tuna purse seine fishery. The author carried out a study on the development of tuna purse seine fishery in Korea and countries concerned-the United States and Japan-because it is recognized to be significant for the further development of this fishery. Just as purse seining was originated in the United States, so tuna purse seining was also pioneered by Californian fishermen in the west coastal waters of the United States (Eastern Pacific Ocean). They started to produce the canned tuna in the early 1900's, and the demand for raw tuna began to be increased rapidly. In those days, tuna was mostly caught by pole-and-line, but the catch amount was far away from the demand. To satisfy this demand, they began to try out fishing tuna by the use of purse seine which had been born in the eastern waters in the 1820's and applied to catch white fishes in the western waters of the United States in those days. Even though their trial was technically successful through severe trial and error, a new problem was raised on the management of tuna resource and the preservation of porpoise which was occassionally caught with tuna. Then the Inter-American Tropical Tuna Commission (IATTC) was established by countries neighboring to the United States in 1950 and they set up the Commission's Yellowfin Regulatory Area (CYRA) and regulated the annual quota for yellowfin. Then, American owners tried to send their seiners to the Western African waters to expand the fishing ground in 1967 and to the Centeral-Western Pacfic in 1974, and the fishing ground was widely expanded. The number of the United States' purse seiners amounted to about 150 in 1980, but the enthusiasm was gradually cooled thereafter and the number of seiner was decreased to 67 in 1986. The landing of tuna by purse seiners in the United States after 1980 maintains 200 thousands M/T or so with a little increase despite the decreasing of domestic seiners. This shows that the landing by foreign seiners are increasing, compared with the landing by domestic seiners are decreasing. In Japan, even though purse seining was introduced in 1880, they had fished tuna by longline and pole-and -line until the tuna purse seining was introduced from the United States again. In the 1960's, Japanese tuna seiners made the exploratory fishing in the South-western Pacific and West African waters with a limited success. In 1971, the government-funded research center "JARMRAC" conducted the exploratory fishing which extended to the Central American waters, the Asia-Pacific Region and the South-western Pacific. It had also much difficulties, till they improved the fishing gear adaptable to the new fishing condition in the South-western Pacific. Japanese government has begun to licence 32 single seiners and 7 group seiners since 1980 and their standard has lasted up to now. The catch in the Pacific Islands Region amounted to 160 thousands M/T in 1986. Korea's tuna purse seine fishery was originated in 1971 by Jedong Industrial Co., Ltd. with three used tuna purse seiners purchased from the United States, and they began to fish in the Eastern Pacific, but failed owing to the superannuation of vessel and the infancy of fishing technique. The second challenge was done by Dongwon Industrial Co., Ltd. in 1979, with one used seiner purchased from the United States, and started to fish in the Eastern Pacific. Even though the first trial was almost unsuccessful but they could obtain the noticeable success by removing the vessel to the South-western Pacific in 1980. This success stimulated the Korean entherprisers to take part in this fishery, and the number of Korean tuna purse seiners has been increased rapidly in accordance with the increased demand for raw tuna. The number of vessels actually at work amounted to 36 in 1990 and they operate in the South-western Pacific. The annual catch of tuna by purse seiners amounted to 170 thousands M/T in 1990 and ranked to one of the major tuna purse seining countries in the world.