• Radiation Oncology Journal
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• v.28 no.1
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• pp.16-22
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• 2010

Purpose: We analyzed the incidence and related factors of radiation dermatitis; at first, to recognize whether a decrease in radiation dermatitis is possible or not in breast cancer patients who received radiation therapy. Materials and Methods: Of 338 patients, 284 with invasive breast cancer who received breast conservation surgery with radiotherapy at Chonbuk National University Hospital from January 2007 to June 2009 were evaluated. Patients who also underwent bolus, previous contralateral breast irradiation and irradiation on both breasts were excluded. For patients who appeared to have greater than moderate radiation dermatitis, the incidence and relating factors for radiation dermatitis were analyzed retrospectively. Results: A total of 207 and 77 patients appeared to have RTOG grade 0/1 or above RTOG grade 2 radiation dermatitis, respectively. The factors found to be statistically significant for the 77 patients who appeared to have greater than moderate radiation dermatitis include the presence of lymphocele due to the stasis of lymph and lymph edema which affect the healing disturbance of radiation dermatitis (p=0.003, p=0.001). Moreover, an allergic reaction to plaster due to the immune cells of skin and the activation of cytokine and concomitant hormonal therapy were also statistically significant factors (p=0.001, p=0.025). Conclusion: Most of the breast cancer patients who received radiation therapy appeared to have a greater than mild case of radiation dermatitis. Lymphocele, lymphedema, an allergy to plaster and concomitant hormonal therapy which affect radiation dermatitis were found to be significant factors. Consequently, we should eliminate lymphocele prior to radiation treatment for patients who appear to have an allergic reaction to plaster. We should also instruct patients of methods to maintain skin moisture if they appear to have a greater than moderate case of radiation dermatitis.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1981.05a
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• pp.12.1-12
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• 1981

The dentigerous cyst originates through alteration of the reduced enamel epithelium after the crown of the tooth has been completely formed, with accumulation of fluid between the reduced enamel epithelium and the tooth crown. The dentigerous or follicular cyst comprises about 20% of all dental cysts. It usually occurs between 20 and 30 years of age but is occasionally seen in children or in old people. The most common sites of this cyst are the mandibular third molar and maxillary cuspid areas, since these are the most commonly impacted teeth. Many of these cysts give no clinical symptoms until noticeable asymmetry of the face develops. Rarely it develops to an ameloblastoma, epidermoid carcinoma and mucoepidermoid carcinoma, so early removal leads to better result. Roentgenographic examination of the jaw involved by a dentigerous cyst will reveal a radiolucent area. Recently the authors have experienced a giant dentigerous cyst which produced the bony deformity of the maxillary and hard palate bone. The cyst was completely removed under the local anesthesia by Caldwell-Luc approach.

• Economic and Environmental Geology
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• v.53 no.4
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• pp.479-489
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• 2020

A fault is a geological structure that can be a migration path or a cap rock of hydrocarbon such as oil and gas, formed from source rock. The fault is one of the main targets of seismic exploration to find reservoirs in which hydrocarbon have accumulated. However, conventional fault detection methods using lateral discontinuity in seismic data such as semblance, coherence, variance, gradient magnitude and fault likelihood, have problem that professional interpreters have to invest lots of time and computational costs. Therefore, many researchers are conducting various studies to save computational costs and time for fault interpretation, and machine learning technologies attracted attention recently. Among various machine learning technologies, many researchers are conducting fault interpretation studies using the support vector machine, multi-layer perceptron, deep neural networks and convolutional neural networks algorithms. Especially, researchers use not only their own convolution networks but also proven networks in image processing to predict fault locations and fault information such as strike and dip. In this paper, by investigating and analyzing these studies, we found that the convolutional neural networks based on the U-Net from image processing is the most effective one for fault detection and interpretation. Further studies can expect better results from fault detection and interpretation using the convolutional neural networks along with transfer learning and data augmentation.

• The Korean Journal of Petroleum Geology
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• v.5 no.1_2 s.6
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• pp.9-15
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• 1997

The study area is located in the Central Bransfield Basin, Antarctica. To analyze the morphology of seafloor, structure of basement, and seismic stratigraphy of the sedimentary layers, we have acquired, processed, and interpreted the multi-channel seismic data. The northwest-southeastern back-arc extension dramatically changes seafloor morphology, volcanic and fault distribution, and basin structure along the spreading ridges. The northern continental shelf shows a narrow, steep topography. In contrast, the continental shelf or slope in the south, which is connected to the Antarctic Peninsula, has a gentle gradient. Volcanic activities resulted in the formation of large volcanos and basement highs near the spreading center, and small-scale volcanic diapirs on the shelf. A very long, continuous normal fault characterizes the northern shelf, whereas several basinward synthetic faults probably detach into the master fault in the south. Four transfer faults, the northwest-southeastern deep-parallel structures, controlled the complex distributions of the volcanos, normal faults, depocenters, and possibly hydrocarbon provinces in the study area. They have also deformed the basement structure and depositional pattern. Even though the Bransfield Basin was believed to be formed in the Late Cenozoic (about 4 Ma), the hydrocarbon potential may be very high due to thick sediment accumulation, high organic contents, high heat flow resulted from the active tectonics, and adequate traps.

• The Korean Journal of Petroleum Geology
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• v.12 no.1
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• pp.27-33
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• 2006

The possibility of oil reserve has been conformed because the oil has been produced by 450 barrel per day in the West Korea Bay basin of the North Korea. There is also possibility of giant oil reserve since it is geographically close to one of the biggest oil fields of Bohai Basin, China. Based on the on-going oil exploration and the present condition of investment, the areas of ongoing oil exploration are three: West Korea Bay B&C prospect explored by Swedish Taurus, the north of West Korea Bay and Anju basin explored by Canadian SOCO, and East Korea Bay explored by Australian Beach Petroleum. However, there is little or no possibility of oil reserve in the rest sea areas of three. Even though oil reserves were discovered in the some parts of land areas such as Kilju and Myungcheon, it was presumed to have no economical efficiency. Geology in West Korea Bay off the North Korea is similar to that in Bohai Bay off China. The basement consists of thick carbonate rock of the Late Proterozoic and Early Paleozoic overlain by Mesozoic ($6,000{\sim}10,000\;m$) and Cenozoic ($4,000{\sim}5,000\;m$) units. Source rocks are Jurassic black shale (3,000 m or more), Cretaceous black shale ($1,000{\sim}2,000\;m$), and pre-Mesozoic carbonates (several thousand meters). Reservoir rocks are Mesozoic-Cenozoic sandstone with high porosity and pre-Mesozoic fractured carbonate rocks. Petroleum raps are of the anticline, fault sealed, buried hill, and stratigraphic types. It absolutely needs to take up a positive attitude, the activation of ocean science and technology exchange, and the joint research and development of modern MT (Marine Technology) considering the state of establishing new international ocean order forcing on building up 200 nautical mile EEZ (exclusive economic zone) among coastal nations. Both South and North Koreas should extend the ocean jurisdiction and contiguity, and MT development dealing with the same sea areas. It is more urgent problem to find a way to have the North Korea participated in, and then to develop ocean management and ocean industry individually.

• Geophysics and Geophysical Exploration
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• v.7 no.3
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• pp.164-173
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• 2004

To delineate geothermal water movement at the Pohang geothermal development site, Self-Potential (SP) survey and monitoring were carried out during pumping tests. Before drilling, background SP data have been gathered to figure out overall potential distribution of the site. The pumping test was performed in two separate periods: 24 hours in December 2003 and 72 hours in March 2004. SP monitoring started several days before the pumping tests with a 128-channel automatic recording system. The background SP survey showed a clear positive anomaly at the northern part of the boreholes, which may be interpreted as an up-flow Bone of the deep geothermal water due to electrokinetic potential generated by hydrothermal circulation. The first and second SP monitoring during the pumping tests performed to figure out the fluid flow in the geothermal reservoir but it was not easy to see clear variations of SP due to pumping and pumping stop. Since the area is covered by some 360 m-thick tertiary sediments with very low electrical resistivity (less than 10 ohm-m), the electrokinetic potential due to deep groundwater flow resulted in being seriously attenuated on the surface. However, when we compared the variation of SP with that of groundwater level and temperature of pumping water, we could identify some areas responsible to the pumping. Dominant SP changes are observed in the south-west part of the boreholes during both the preliminary and long-term pumping periods, where 3-D magnetotelluric survey showed low-resistivity anomaly at the depth of $600m\~1,000m$. Overall analysis suggests that there exist hydraulic connection through the southwestern part to the pumping well.

• Economic and Environmental Geology
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• v.53 no.3
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• pp.245-258
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• 2020

In this study, a data-driven response surface method using the results acquired from the numerical simulation is developed to evaluate the potential storage capacity of groundwater due to the construction of a groundwater dam. The hydraulic conductivities of alluvium and basement rock, depth and slope of the channel are considered as the natural conditions of the location for groundwater dam construction. In particular, the probability models of the hydraulic conductivities and the various types of geometry of the channel are considered to ensure the reliability of the numerical simulation and the generality of the developed estimation model. As the results of multiple simulations, it can be seen that the hydraulic conductivity of basement rock and the depth of the channel greatly influence to the groundwater storage capacity. In contrast, the slope of the channel along the groundwater flow direction shows a relatively lower impact on the storage capacity. Based on the considered natural conditions and the corresponding numerical simulation results, the storage capacity estimation model is developed applying an artificial neural network as the nonlinear regression model for training. The developed estimation model shows a high correlation coefficient (>0.9) between the simulated and the estimated storage amount. This result indicates the superiority of the developed model in evaluating the storage capacity of the potential location for groundwater dam construction without the numerical simulation. Therefore, a more objective and efficient comparison for the storage capacity between the different potential locations can be possibly made based on the developed estimation model. In line with this, the proposed method can be an effective tool to assess the optimal location of groundwater dam construction across Korea.

• 한국노년학
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• v.29 no.2
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• pp.645-656
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• 2009

The purpose of this study was to address the current status of hospital-based home care(HBHC). We analyzed the data on HBHC from national electronic data information of Health Insurance Review Agency. Beside, we surveyed 75 hospital-based home care agency. In 2006, 20,343 elderly(64.0% from all HBHC user) used 333,889 visits(76.8%from all visits). Medical diagnosis was composed of circulatory disease including cerebrovascular diseases 41.3%, endocrine system disease including Diabetes mellitus 10.4%, neoplasm 9.7%. Some of subjects used HBHC in excess of maximum covered 8 visits a month by National Health Insurance, decubitus 7.0%, the cancer 5.4%, the diabetes 2.5%, the hypertension 1.1%, and the stroke 0.9%. This results will contribute to expand the coverage of hospital-based home care by National Health Insurance. There was distribution difference in medical diagnosis and nursing intervention between HBHC and Public health center-based home care(PBHC) subjects. Therefore, HBHC subjects had more severe medical diagnosis, and were intervened more injections, examinations, than PBHC subjects. These differences must be considered to set up functional role among the three types of home visit care.

• Journal of Gastric Cancer
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• v.9 no.4
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• pp.215-222
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• 2009

Purpose: Billroth II gastroenterostomy is a typical reconstruction method after distal gastrectomy for gastric carcinoma, but it has problems, especially frequent reflux esophagitis. Various methods have been tried to address this problem. Among them are Braun enteroenterostomy and Roux-en-Y gastroenterostomy, which are performed separately according to the size of the gastric remnant. The aim of our study was to determine whether these applications are compatible. Materials and Methods: Between September 2003 and April 2007, we performed Roux-en-Y gastroenterostomy operations (14 patients) when the size of the gastric remnant was <10%, Braun enteroenterostomy (17 patients) when the size was between 10 and 20%, and Billroth II gastroenterostomy (14 patients) when the size was between 20 and 40% after subtotal gastrectomy for gastric cancer by a single surgeon at our hospital. We analyzed the results of each treatment. We evaluated the symptoms and endoscopic findings using questionnaires and hospital records. To evaluate nutritional states, we reviewed albumin and hemoglobin levels and body weight changes. Results: All operations were performed safely mortality was 0% and postoperative complications were 8.9%. On endoscopy, reflux gastritis was observed to occur in 7.63%, 18.65% and 40.0%, respectively, of patients who had undergone Roux-en-Y, Braun and Billroth II operations (P=0.13). Reflux esophagitis was observed in 1 patient in the Roux-en-Y group and 1 patient in the Braun group. Endoscopic gastrostasis was observed in 2 patients in the Roux-en-Y group, one of which was thought to cause reflux esophagitis. Patients in the Roux-en-Y group and Braun groups ingested a lower volume of food than did those in the Billroth II group (respectively, 7.1%, 0.0% and 28.7%) and complained less of postprandial discomforts (respectively, 14.3%, 23.5% and 57.1%) and reflux symptoms (respectively 0.0%, 11.8% and 42.9%). Conclusion: The application of Braun enteroenterostomy and Roux-en-Y gastroenterostomy to the small gastric remnant may be effective for reducing reflux symptoms and abdominal discomfort after distal gastric resection. We recommend Roux-en-Y gastroenterostomy when the size of the gastric remnant is <10%, and Braun anastomosis in the others. It will need to be determined which reconstructive procedure is better for many different conditions.

• Economic and Environmental Geology
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• v.48 no.4
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• pp.301-312
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• 2015

A commercial gas field was found in the southwestern continental shelf of the Ulleung Basin, East Sea in the late 1990s. To develop additional gas field, an exploration well was drilled through the coarse infill of submarine canyon near the gas field, but it was uneconomic to develop hydrocarbons. Using newly acquired deep seismic reflection and previous well data, we have identified additional geological structure which has hydrocarbon potentials below submarine canyons in the southwestern margin of the basin. Based on the interpretation of the deep seismic reflection and well data, the sequences of the study area can be classified into the syn-rift megasequence(MS1), post-rift megasequence(MS2), syn-compressional megasequence(MS3), and post-compressional megasequence(MS4) in relation to the tectonic events. MS1, deposited simultaneously with the basin formation before the middle Miocene, is characterized by chaotic seismic facies with low- to moderate-amplitude and low frequency reflections. MS2 comprises laterally continuous, low- to moderate-amplitude reflections, showing progradational stacking patterns due to high rates of sediment supply during basin expansion in the middle Miocene. MS3 is mainly composed of continuous reflections with high amplitude and moderate- to high-frequency which are interpreted as coarse-grained sediments. The coarse-grained sediments of MS3 sequence is widely truncated by several submarine canyons which filled with fine-grained sediment of MS4 to form a stratigraphic trap of hydrocarbon. Therefore, the reservoir and seal of the hydrocarbon trap in the study area are coarse-grained sediment of MS3 and submarine canyon filled with fine-grained sediment of MS4, respectively. A flat-spot seismic anomaly, which may indicate the presence of hydrocarbon, is observed within the stratigraphic trap.