• Korean Journal of Environment and Ecology
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• v.24 no.2
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• pp.166-177
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• 2010

This study is to identify potential factors to impact on appearance of wildbirds which live in the core forest around urban area in Gangdong-gu, Seoul. As a result of analysis of, studies on biotope showed most of urbanization biotope was biotope of residential areas with high green coverage and biotope of residential and business areas with low green coverage while most of biotope of green and openspace was core green biotope. The research area was divided into several blocks based on biotope types in the urbanization areas excluding green and openspace. As a result of research on wildbirds, total 51 species 3,419 individuals appeared in spring and total 35 species 4,213 individuals appeared in winter. 24 wild bird species were selected as subjects of this study among 31 species seen in urbanization areas, since urban birds, rapacious birds, waterside birds were excluded from the study for the proper consideration. Then this study looked at how many species and individuals of the subjects were observed at each research block in urbanization areas during spring and winter separately. Landuse structure and green structure in each block were examined to see whether these structures affect the number of wild birds observed in urbanization areas of Gangdong-gu. Furthermore, the distance between these blocks and green was assessed. While studying the potential links between the landuse structure and the number of wild birds observed in urbanization areas of Gangdong-gu, block area, green coverage, and building-to-land ratio were believed to affect the number of types and species of wild birds in the research area. In terms of correlation analysis of whether green structure affected the number of wild birds observed in urbanization areas of Gangdong-gu, crown volume of layers, the average green patch area, the average height of canopy layer were found to have an impact not only on the number of types but also species of wild birds in the research area.

• Journal of Intelligence and Information Systems
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• v.21 no.3
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• pp.19-36
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• 2015

Social media is an emerging issue in content services and in current business environment. YouTube is the most representative social media service in the world. YouTube is different from other conventional content services in its open user participation and contents creation methods. To promote a content in YouTube, it is important to understand the diffusion phenomena of contents and the network structural characteristics. Most previous studies analyzed impact factors of contents diffusion from the view point of general behavioral factors. Currently some researchers use network structure factors. However, these two approaches have been used separately. However this study tries to analyze the general impact factors on the view count and content based network structures all together. In addition, when building a content based network, this study forms the network structure by analyzing user comments on 22,370 contents of YouTube not based on the individual user based network. From this study, we re-proved statistically the causal relations between view count and not only general factors but also network factors. Moreover by analyzing this integrated research model, we found that these factors affect the view count of YouTube according to the following order; Uploader Followers, Video Age, Betweenness Centrality, Comments, Closeness Centrality, Clustering Coefficient and Rating. However Degree Centrality and Eigenvector Centrality affect the view count negatively. From this research some strategic points for the utilizing of contents diffusion are as followings. First, it is needed to manage general factors such as the number of uploader followers or subscribers, the video age, the number of comments, average rating points, and etc. The impact of average rating points is not so much important as we thought before. However, it is needed to increase the number of uploader followers strategically and sustain the contents in the service as long as possible. Second, we need to pay attention to the impacts of betweenness centrality and closeness centrality among other network factors. Users seems to search the related subject or similar contents after watching a content. It is needed to shorten the distance between other popular contents in the service. Namely, this study showed that it is beneficial for increasing view counts by decreasing the number of search attempts and increasing similarity with many other contents. This is consistent with the result of the clustering coefficient impact analysis. Third, it is important to notice the negative impact of degree centrality and eigenvector centrality on the view count. If the number of connections with other contents is too much increased it means there are many similar contents and eventually it might distribute the view counts. Moreover, too high eigenvector centrality means that there are connections with popular contents around the content, and it might lose the view count because of the impact of the popular contents. It would be better to avoid connections with too powerful popular contents. From this study we analyzed the phenomenon and verified diffusion factors of Youtube contents by using an integrated model consisting of general factors and network structure factors. From the viewpoints of social contribution, this study might provide useful information to music or movie industry or other contents vendors for their effective contents services. This research provides basic schemes that can be applied strategically in online contents marketing. One of the limitations of this study is that this study formed a contents based network for the network structure analysis. It might be an indirect method to see the content network structure. We can use more various methods to establish direct content network. Further researches include more detailed researches like an analysis according to the types of contents or domains or characteristics of the contents or users, and etc.

• Korean Journal of Environment and Ecology
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• v.35 no.2
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• pp.164-180
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• 2021

Plants Social Network(PSN) analysis combines the plant sociological method and the social network analysis to understand plant society focusing on environmental-to-plant and plant-to-plant relationships. PSN is at an early stage of research and require comparing plant society analyses in various environments and existing interspecies binding analysis. This study conducted a vegetation structural analysis of Mudeungsan National Park and compared the existing interspecies connection analysis with the PSN. A total of 60 plots were established for a survey on the Old Trail. The TWINSPAN and DCA analysis showed that the 60 survey plots were divided into the Quercus serrata-Pinus densiflora community (Community I) and the Quercus mongolica community (Community II) based on an altitude of 800 meters. We performed the interspecies correlation with more than 30% emergence frequency and the DCA analysis and compared the results with a focus on the major species in each colony. The results showed that Quercus serrata had a correlation of -0.450^** and -0.375^** with Pinus densiflora and Quercus mongolica, respectively. The DCA analysis also confirmed that Quercus serrata was located close to Pinus densiflora and far from Quercus mongolica along one axis. For the PSN analysis of PSN, 40 survey plots were added to investigate the species appearing in a total of 100 survey plots. The network structural analysis showed 378 links and a species having an average of 6 interspecies bindings. The density was 0.097, the diameter was 7, and the average path distance was 2.788, similar to the PSN analysis results of the Busan Metropolitan City. The plant social network analysis showed similar results to the existing interspecies combination analysis, enabling analyzing more data than the existing methods and observing the structure of plant society.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.604-617
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• 2018

As the depletion of forests became more widespread due to the increase in the number of roads, the research was conducted on the relationship between temperature and humidity in the forests, assuming that the forests around the roads were affected. Through the forest monitoring, the temperature and humidity of coniferous forests and broadleaf forests in Sedong and Gongju areas were observed at three point of 10m, 20m and 30m from the road boundary to the inside of the forest, respectively. In Yeongdong area, for more reliable results, it was observed from the point of 0m, 10m, and 20m. During the study period, so it was expected the change in tree growth was small, the change of temperature and humidity inside the forest by the road was compared with the temperature and humidity from the road to the inside of the forest from September 2017 to January 2018, the changes of temperature and humidity inside the forest due to linear development such as roads were quantitatively analyzed. Using the HOBO data logger (MX2301, Onset Corp.), the temperature and humidity changes of each site were measured, and the average of the changes have been analyzed monthly. In the case of Gongju coniferous forests in September 2017, the average weekly temperature is $0.57^{\circ}C$ higher than the forest outside from the forest boundary and $1.23^{\circ}C$ higher than the inside of the forest, at night in November 2017, in Sedong broadleaf forests. That is, the ability to control the temperature and humidity of the forests along the road was larger and less variable as the distance from the road boundary to the inside of the forest increased. In this study, it is considered that the high degree of change in temperature and humidity of the forest and the surrounding area due to artificial linear development such as roads will affect the growth of trees. This results could serve as a basis for studying the quantitative scope of linear development affecting forest growth and for managing forest change caused by linear development.

• The Journal of Korean Society for Radiation Therapy
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• v.31 no.1
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• pp.7-15
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• 2019

Purpose: The purpose of this study is to evaluate beam delivery accuracy for small sized lung SBRT through experiment. In order to assess the accuracy, Eclipse TPS(Treatment planning system) equipped Acuros XB and radiochromic film were used for the dose distribution. Comparing calculated and measured dose distribution, evaluated the margin for PTV(Planning target volume) in lung tissue. Materials and Methods : Acquiring CT images for Rando phantom, planned virtual target volume by size(diameter 2, 3, 4, 5 cm) in right lung. All plans were normalized to the target Volume=prescribed 95 % with 6MV FFF VMAT 2 Arc. To compare with calculated and measured dose distribution, film was inserted in rando phantom and irradiated in axial direction. The indexes of evaluation are percentage difference(%Diff) for absolute dose, RMSE(Root-mean-square-error) value for relative dose, coverage ratio and average dose in PTV. Results: The maximum difference at center point was -4.65 % in diameter 2 cm size. And the RMSE value between the calculated and measured off-axis dose distribution indicated that the measured dose distribution in diameter 2 cm was different from calculated and inaccurate compare to diameter 5 cm. In addition, Distance prescribed 95 % dose($D_{95}$) in diameter 2 cm was not covered in PTV and average dose value was lowest in all sizes. Conclusion: This study demonstrated that small sized PTV was not enough covered with prescribed dose in low density lung tissue. All indexes of experimental results in diameter 2 cm were much different from other sizes. It is showed that minimized PTV is not accurate and affects the results of radiation therapy. It is considered that extended margin at small PTV in low density lung tissue for enhancing target center dose is necessary and don't need to constraint Maximum dose in optimization.

• The Transactions of the Korea Information Processing Society
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• v.13 no.4
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• pp.189-198
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• 2024

Lipreading is one of the important parts of speech recognition, and several studies have been conducted to improve the performance of lipreading in lipreading systems for speech recognition. Recent studies have used method to modify the model architecture of lipreading system to improve recognition performance. Unlike previous research that improve recognition performance by modifying model architecture, we aim to improve recognition performance without any change in model architecture. In order to improve the recognition performance without modifying the model architecture, we refer to the cues used in human lipreading and set other regions such as chin and cheeks as regions of interest along with the lip region, which is the existing region of interest of lipreading systems, and compare the recognition rate of each region of interest to propose the highest performing region of interest In addition, assuming that the difference in normalization results caused by the difference in interpolation method during the process of normalizing the size of the region of interest affects the recognition performance, we interpolate the same region of interest using nearest neighbor interpolation, bilinear interpolation, and bicubic interpolation, and compare the recognition rate of each interpolation method to propose the best performing interpolation method. Each region of interest was detected by training an object detection neural network, and dynamic time warping templates were generated by normalizing each region of interest, extracting and combining features, and mapping the dimensionality reduction of the combined features into a low-dimensional space. The recognition rate was evaluated by comparing the distance between the generated dynamic time warping templates and the data mapped to the low-dimensional space. In the comparison of regions of interest, the result of the region of interest containing only the lip region showed an average recognition rate of 97.36%, which is 3.44% higher than the average recognition rate of 93.92% in the previous study, and in the comparison of interpolation methods, the bilinear interpolation method performed 97.36%, which is 14.65% higher than the nearest neighbor interpolation method and 5.55% higher than the bicubic interpolation method. The code used in this study can be found a https://github.com/haraisi2/Lipreading-Systems.

• The Korean Journal of Pain
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• v.1 no.1
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• pp.34-46
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• 1988

Intractable pain from advanced carcinoma of the upper abdomen is difficult to manage. One method used to control pain associated with these malignancies is to block off the splanchnic nerve. In 1919 Kappis described a technique by which the splanchnic nerve of the upper abdomen could be anesthetized, using a percutaneous injection. This method has been used for the relief of upper abdominal pain due to hematoma and cancer of the pancreas, stomach, gall bladder, bile duct, and colon. During the Period from November 1968 to January 1986, this method was used in 208 cases of malignancy at Severance Hospital and clinically evaluated. Patients were retroactively grouped according to the stage of development of technique used. Twelve patients who received the treatment in the period from November 1968 to March 1977 were designate4i as group 1, 26 patients from April 1977 to April 1979 as group 2, and 170 from May 1979 to January 1986 as group 3. The results are as follows: 1) The number of patients receiving splanchnic nerve block has been increasing since 1977. 2) A total of 208 patients, including 133 males and 75 females, ranging in age from 18 to 84 and averaging 51. 3) The causes of pain were stomach cancer 90, pancreatic cancer 69, and miscellaneous cancer 49 cases respectively. 4) There were 57.7% who had surgery. and 3.7% of whom had chemotherapy before the splanchnic nerve block was done. 5) These blocks were carried out with the patient in the prone position as described by Dr. Moore. For group 2 and 3, C-arm image intensifier was used. In group 1, a 22 gauze loom long needle was inserted at the lower border of the 12th rib on each aide about 7\;cm from the midline. The average distance from the midline was $6.60{\pm}0.61\;cm$ on the left side and $6.60{\pm}0.83\;cm$ on the right side in group 2, and $5.46{\pm}0.76\;cm$ on the left side and $5.49{\pm}0.69\;cm$ on the right side in group 3. The average depth to which the needle was inserted was $8.60{\pm}0.52\;cm$ on the left side and $8.74{\pm}0.60\;cm$ on the right side in group 2, and $8.96{\pm}0.63\;cm$ on the left side and $9.18{\pm}0.57\;cm$ on the right side in group 3. 6) The points of the inserted needles were positioned in the upper quarter anteriorly, 51.8% on the left side and 54.4% n the right side of the L1 vertebra by lateral roentgenogram in group 3. The inserted needle points were located in the upper and anterolateral part, of the L1 vertebra 68.5% on the left side and 60.6won the right side, on the anteroposterior rentgenogram in group 3. The needle tip was not advanced beyond the anterior margin of the vertebral body. 7) In some case of group 3, contrast media was injected before the block was done. It shows, the spread upward along the anterior mal gin of the vertebral body. 8) The concentration and the average amount of drug used in each group was as follows: In group 1, $39.17{\pm}6.69\;ml$ of 0.5% -l% lidocaine or 0.25% bupivacaine were injected for the test block and one to three days after the test block $40.00{\pm}4.26\;ml$ of 50% alcohol was injected for the semipermanent block. In group 2, $13.75{\pm}4.88\;ml$ of 1% lidocaine were used as the test block and followed by $46.17{\pm}4.37\;ml$ of 50% alcohol was injected as the semipermanent block. In group 3, $15.63{\pm}1.19\;ml$ of 1% lidocaine for test block followed by $15.62{\pm}1.20\;ml$ of pure alcohol and $16.05{\pm}2.58\;ml$ of 50% alcohol for semipermanent block were injected. 9) The result of the test block was satisfactory in all cases. However the semipermanent block was 83.3 percent of the patients in group 1 who received relief from pain for at least 2 weeks after the block, 73.1% in group 2, and 91.8% in group 3. In these unsuccessful cases, 2 cases in group 1 were controlled by narcotics but 7 cases in group 2 and 14 cases in group 3 received the same splanchnic nerve block 1 or 2 times again within 2 weeks. But, in some cases it was 3 to i months before the 2nd block and in 1 cases even 7 years. 10) The most common complications of splanchnic nerve block were hypotensino(25.5%) occasional flushing of the face, nausea, vomiting, and chest discomfort. 11) For the patients in group 3, the supplemental block most commonly used was a continuous epidural block; it was used as a diagnostic block and to afford relief from pain before the splanchnic nerve block was done. 12) The interval between the receiving of the alcohol block and discharge was from 5 to 8 days in 61 cases(31.1%) and from 1 to 2 days in 48 cases(24.5%). From the above results, it can be concluded that the splanchnic nerve block done in the prone position with pure and 50% alcohol immediately after an effective test block with 1% lidocaine under C-arm fluoroscopic control is satisfactory and reliable. How to minimize the repeat block is still a problem to be solved.

• Korean Journal of Agricultural Science
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• v.13 no.1
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• pp.1-16
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• 1986

This experiment was carried out to obtain genetic information for future corn breeding. The materials used for the study were obtained from the nationwide collection of Korean local corn lines. A total of 262 lines were used for the study of morphological characters and for the classification of lines. Results obtained are summarized as follows; 1. The days to flowering of lines ranged from 57 days to 87 days. Most lines had an average of 67 days of flowering days. 2. The number of tillers of lines showed a lot of variation among lines with 49.2% of coefficient of variation. 3. The coefficients of variation computed based on the phenotypic observation or measurement of each line were 36.1%, 27.2%, 20.0%, 16.4% and 16.3% for kernel weight per ear, 100 kernel weight, ear height, plant height and ear length, respectively. 4. Ear height, ear length, ear diameter, tiller number and days to flowering were highly and positively correlation with the plant height. Kernel size, ear size, and plant height were highly correlated with 100 kernel weight and kernel weight per ear. 5. The 262 corn lines were possibly classified into four major groups by the Euclidean distance. Group I comprised 110 lines, group II 74 lines, group III 66 lines and group IV 12 lines, respectively. Group I was characterized as having early maturity, medium plant height large kernel size and large ear size. Group II had medium maturity, short plant height, medium kernel size and small ear size. Group III had medium maturity, medium plant height, large kernel size and medium ear size. Group IV had late maturity, long plant height, small kernel size, small ear size and many tillering. 6. The plant height showed significant difference between group I and II, II and III, and II and IV group. No statistical differences were observed between group III and IV. The ear size of group I was significantly different from those of group II, III and IV. Also difference of ear size between group II and III was significant. The kernel size, 100 kernel weight and kernel weight per ear were all significantly different among all groups classified. The row number was different between group I and II. The row number of lines in group IV was significantly different with group I, II, III respectively. The number of tillers and flowering days of lines in group IV were greatly different from those of group I, II and III. 7. The corn lines collected from northwest plain regions and middle hilly regions in Korea had medium maturity, medium plant height, large ear and large kernels. The corn lines from middle eastern hilly regions had medium size of ear kernels. The corn lines from middle southern hilly regions had late maturity, small kernel size and many tillers. The corn lines from southwest plain areas had late maturity, long plant height and many tillers.

• Journal of Radiation Protection and Research
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• v.27 no.1
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• pp.1-10
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• 2002

High energy photon beams from medical linear accelerators produce large scattered radiation by various components of the treatment head, collimator and walls or objects in the treatment room including the patient. These scattered radiation do not provide therapeutic dose and are considered a hazard from the radiation safety perspective. Scattered dose of therapeutic high energy radiation beams are contributed significant unwanted dose to the patient. ICRP take the position that a dose of 500mGy may cause abortion at any stage of pregnancy and that radiation detriment to the fetus includes risk of mental retardation with a possible threshold in the dose response relationship around 100 mGy for the gestational period. The ICRP principle of as low as reasonably achievable (ALARA) was recommended for protection of occupation upon the linear no-threshold dose response hypothesis for cancer induction. We suggest this ALARA principle be applied to the fetus and testicle in therapeutic treatment. Radiation dose outside a photon treatment filed is mostly due to scattered photons. This scattered dose is a function of the distance from the beam edge, treatment geometry, primary photon energy, and depth in the patient. The need for effective shielding of the fetus and testicle is reinforced when young patients ate treated with external beam radiation therapy and then shielding designed to reduce the scattered photon dose to normal organs have to considered. Irradiation was performed in phantom using high energy photon beams produced by a Varian 2100C/D medical linear accelerator (Varian Oncology Systems, Palo Alto, CA) located at the Yonsei Cancer Center. The composite phantom used was comprised of a commercially available anthropomorphic Rando phantom (Phantom Laboratory Inc., Salem, YN) and a rectangular solid polystyrene phantom of dimensions $30cm{\times}30cm{\times}20cm$. the anthropomorphic Rando phantom represents an average man made from tissue equivalent materials that is transected into transverse 36 slices of 2.5cm thickness. Photon dose was measured using a Capintec PR-06C ionization chamber with Capintec 192 electrometer (Capintec Inc., Ramsey, NJ), TLD( VICTOREEN 5000. LiF) and film dosimetry V-Omat, Kodak). In case of fetus, the dosimeter was placed at a depth of loom in this phantom at 100cm source to axis distance and located centrally 15cm from the inferior edge of the $30cm{\times}30cm^2$ x-ray beam irradiating the Rando phantom chest wall. A acryl bridge of size $40cm{\times}40cm^2$ and a clear space of about 20 cm was fabricated and placed on top of the rectangular polystyrene phantom representing the abdomen of the patient. The leaf pot for testicle shielding was made as various shape, sizes, thickness and supporting stand. The scattered photon with and without shielding were measured at the representative position of the fetus and testicle. Measurement of radiation scattered dose outside fields and critical organs, like fetus position and testicle region, from chest or pelvic irradiation by large fie]d of high energy radiation beam was performed using an ionization chamber and film dosimetry. The scattered doses outside field were measured 5 - 10% of maximum doses in fields and exponentially decrease from field margins. The scattered photon dose received the fetus and testicle from thorax field irradiation was measured about 1 mGy/Gy of photon treatment dose. Shielding construction to reduce this scattered dose was investigated using lead sheet and blocks. Lead pot shield for testicle reduced the scatter dose under 10 mGy when photon beam of 60 Gy was irradiated in abdomen region. The scattered photon dose is reduced when the lead shield was used while the no significant reduction of scattered photon dose was observed and 2-3 mm lead sheets refuted the skin dose under 80% and almost electron contamination. The results indicate that it was possible to improve shielding to reduce scattered photon for fetus and testicle when a young patients were treated with a high energy photon beam.

• Journal of Radiation Protection and Research
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• v.23 no.3
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• pp.139-147
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• 1998

Purpose: Tissue inhomogeneity such as lung affects tumor dose as well as transmission dose in new concept of on-line dosimetry which estimates tumor dose from transmission dose using the new algorithm. This study was carried out to confirm accuracy of correction by tissue density in tumor dose estimation utilizing transmission dose. Methods: Cork phantom (CP, density $0.202\;gm/cm^3$) having similar density with lung parenchyme and polystyrene phantom (PP, density $1.040\;gm/cm^3$) having similar density with soft tissue were used. Dose measurement was carried out under condition simulating human chest. On simulating AP-PA irradiation, PPs with 3 cm thickness were placed above and below CP, which had thickness of 5, 10, and 20 cm. On simulating lateral irradiation, 6 cm thickness of PP was placed between two 10 cm thickness CPs additional 3 cm thick PP was placed to both lateral sides. 4, 6, and 10 MV x-ray were used. Field size was in the range of $3{\times}3$ cm through $20{\times}20$ cm, and phantom-chamber distance (PCD) was 10 to 50 cm. Above result was compared with another sets of data with equivalent thickness of PP which was corrected by density. Result: When transmission dose of PP was compared with equivalent thickness of CP which was corrected with density, the average error was 0.18 (${\pm}0.27$) % for 4 MV, 0.10 (${\pm}0.43$) % for 6 MV, and 0.33 (${\pm}0.30$) % for 10 MV with CP having thickness of 5 cm. When CP was 10 cm thick, the error was 0.23 (${\pm}0.73$) %, 0.05 (${\pm}0.57$) %, and 0.04 (${\pm}0.40$) %, while for 20 cm, error was 0.55 (${\pm}0.36$) %, 0.34 (${\pm}0.27$) %, and 0.34 (${\pm}0.18$) % for corresponding energy. With lateral irradiation model, difference was 1.15 (${\pm}1.86$) %, 0.90 (${\pm}1.43$) %, and 0.86 (${\pm}1.01$) % for corresponding energy. Relatively large difference was found in case of PCD having value of 10 cm. Omitting PCD with 10 cm, the difference was reduced to 0.47 (${\pm}$1.17) %, 0.42 (${\pm}$0.96) %, and 0.55 (${\pm}$0.77) % for corresponding energy. Conclusion When tissue inhomogeneity such as lung is in tract of x-ray beam, tumor dose could be calculated from transmission dose after correction utilizing tissue density.