• The Journal of the Korea Contents Association
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• v.5 no.5
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• pp.59-64
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• 2005

The biometrics of iris is a very accurate authentication method. The biometrics of iris can recognize and identify a person for shortly. But the image of iris is changed by transformation of body in the life. The existing iris authentication system has problem that can be mis-recognized. In this paper, we proposed and implemented Renewable Iris Authentication Algorithm(RIAA) for biometrics in authentication system. This algorithm tries to present a new way to people identification, we show contour line when shift take photograph in regular side. Namely, it generate iris code based on boundary of projection or submergence side and compared to original, so that it describes iris identification method to people identification.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.385-392
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• 2023

Caroli's disease is a fibrocystic liver disease. Autosomal recessive disorder is characterized by congenital multiple dilatation of the bile duct. Computerized tomography, magnetic resonance imaging, cholangiography and ultrasound are among the methods for diagnosing caroli disease. Computerized tomography is essential for detecting and distinguishing fibroplastic liver disease and is useful for determining intrahepatic bile duct dilatation. However, awareness of the possible side effects of using contrast mediums is necessary. A typical method of magnetic resonance cholangiography is used for magnetic resonance imaging. A non-invasive examination can reduce the pain of the patient, and the anatomical structure of the bile pancreatic duct and the presence or absence of lesions can be easily and quickly observed. Biliary contrast is an effective diagnostic method that can directly visualize various cystic dilatations throughout the enlarged bile duct. However, since this procedure is also an invasive procedure, it is recommended not for diagnosis but for treatment purposes. Ultrasonography can confirm similar findings to computerized tomography. The hepatic artery root is difficult to prove with conventional grayscale ultrasound. However, it is of clinical value in that it can not only describe dilated bile ducts with vascular roots in the tube but also easily identify color Doppler signals in the tube. With the development of video diagnostics, early diagnosis has become possible through computerized tomography, magnetic resonance imaging, cholangiography, and ultrasound. In order to further contribute to the development of video diagnostics so that long-term prognosis can be improved after treatment through early diagnosis, we examined what aspects of each test's caroli disease appear.

• Journal of the Korean Society of Radiology
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• v.7 no.1
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• pp.9-15
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• 2013

In this study, texture feature analysis (TFA) algorithm to automatic recognition of liver disease suggests by utilizing computed tomography (CT), by applying the algorithm computer-aided diagnosis (CAD) of hepatocellular carcinoma (HCC) design. Proposed the performance of each algorithm was to comparison and evaluation. In the HCC image, set up region of analysis (ROA, window size was $40{\times}40$ pixels) and by calculating the figures for TFA algorithm of the six parameters (average gray level, average contrast, measure of smoothness, skewness, measure of uniformity, entropy) HCC recognition rate were calculated. As a result, TFA was found to be significant as a measure of HCC recognition rate. Measure of uniformity was the most recognition. Average contrast, measure of smoothness, and skewness were relatively high, and average gray level, entropy showed a relatively low recognition rate of the parameters. In this regard, showed high recognition algorithms (a maximum of 97.14%, a minimum of 82.86%) use the determining HCC imaging lesions and assist early diagnosis of clinic. If this use to therapy, the diagnostic efficiency of clinical early diagnosis better than before. Later, after add the effective and quantitative analysis, criteria research for generalized of disease recognition is needed to be considered.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.11
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• pp.927-936
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• 2014

This paper presents development and verification of the progressive failure analysis upon the composite laminates. Strength and stiffness of the fiber-reinforced composite are analyzed by property degradation approach with emphasis on the material nonlinearity and continuum damage mechanics (CDM). Longitudinal and transverse tensile modes derived from Hashin's failure criterion are used to predict the thresholds for damage initiation and growth. The modified Newton-Raphson iterative procedure is implemented for determining nonlinear elastic and viscoelastic constitutive relations. Laminar properties of the composite are obtained by experiments. Prediction on the un-notched tensile (UNT) specimen is performed under the laminate level. Stress-strain curves and strength results are compared with the experimental measurement. It is concluded that the present nonlinear CDM approach is capable of predicting the strength and stiffness more accurately than the corresponding linear CDM one does.

• Progress in Medical Physics
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• v.21 no.1
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• pp.93-98
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• 2010

The aim of this work was to establish the methodology for event positioning by measuring depth of interaction (DOI) information and to evaluate the system sensitivity and spatial resolution of the new detector for I-125 and Tc-99m imaging. For this purpose, a Monte Carlo simulation tool, DETECT2000 and GATE were used to model the energy deposition and light distribution in the detector and to validate this approach. Our proposed detector module consists of a monolithic CsI(Tl) crystal with dimensions of $50.0{\times}50.0{\times}3.0\;mm^3$. The results of simulation demonstrated that the resolution is less than 1.5 mm for both I-125 and Tc-99m. The main advantage of the proposed detector module is that by using 3 mm thick CsI(Tl) with maximum-likelihood position-estimation (MLPE) method, high resolution I-125 imaging and high sensitivity Tc-99m imaging are possible. In this paper, we proved that our new detector to be a reliable design as a detector for a multi-energy SPECT.

• Geophysics and Geophysical Exploration
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• v.16 no.1
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• pp.6-17
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• 2013

Multicomponent seismic data including both P- and PS-waves have advantages in discriminating the type of pore fluid, characterizing the lithologic attributes and producing the high resolution image. However, multicomponent seismic data recorded at the vertical and horizontal component receivers contain both P- and PS-waves which have different features, simultaneously. Therefore, the wavefield separation of P- and PS-waves as a preprocessing is inevitable in order to use the multicomponent seismic data successfully. In this study, we analyzed the previous study of the wavefield separation method suggested by Jeong and Byun in 2011, where the approximated reflection angle calculated only from one refernce depth is used in rotation transform, and showed its limitation for seismic data containing various reflected events from the multi-layered structure. In order to overcome its limitation, we suggested a new effective wavefield separation method of P- and PS-waves. In new method, we calculate the reflection angles with various reference depths and apply rotation transforms to the data with those reflection angles. Then we stack all results to obtain the final separated data. To verify our new method, we applied it to the synthetic data sets from a multi-layered model, a fault model, and the Marmousi-2 model. The results showed that the proposed method separated successfully P- and PS-reflection events from the multicomponent data from mild dipping layered model as long as the dip is not too steep.

• Journal of the Korean GEO-environmental Society
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• v.23 no.3
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• pp.15-22
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• 2022

This study aims to observe the swelling representative rocks in Korea and to suggest improvements in the use of test methods and prior analysis in relation to the weathering of rocks. The swelling test and analysis were performed on the drilling cores obtained for the ground investigation at the domestic highway construction site. For the method of determining the absorption expansion index of rocks, the method proposed in "Standard Methods for Sample Collection and Specimen Preparation" of ISRM and Korean Rock Engineers Standard Rock Test Method was used. The specimen for the measurement of the expansion displacement was cylindrical with a height of 10 cm and a diameter of 5 cm. The existing swelling analysis method evaluates the sensitivity to weathering by using the maximum expansion displacement, but since the classification by bedrock grade is unclear, it is reasonable to use the rate of change of the expansion displacement according to the immersion time. It is necessary to conduct an experiment to distinguish between weathering and fault deterioration. In addition, long-term weathering prediction technology for each cancer type is needed through the expansion displacement analysis of the chemical weathering stage.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.2
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• pp.9-13
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• 2016

Purpose PET-CT examinations using $^{18}F-FDG$ to treat urinary system cancer are limited in terms of anatomical structure and excretion route of $^{18}F-FDG$. But one of the ongoing examinations utilizing $^{11}C-Acetate$ can compensate for such defects. We would like to introduce a clinical application of $^{11}C-Acetate$ PET-CT in urinary cancer patients. Materials and Methods We conducted a clinical survey of 22 patients diagnosed with urinary cancer at our hospital, 10 prostate cancer patients, 10 renal cell carcinoma patients, and 2 bladder cancer patients. All patients were performed $^{18}F-FDG$ PET-CT examinations, $^{11}C-Acetate$ examinations were performed after two weeks on average. The equipment used to D-710 PET-CT in GE Company and we performed PET-CT procedures 15 minutes after injecting $^{11}C-Acetate$, and a medical doctor from the department of nuclear medicine appraised and compared images between $^{18}F-FDG$ and $^{11}C-Acetate$. Results According to our survey, prostate cancer patients generally had lower uptake of $^{18}F-FDG$ than other cancer patients did. In 2 out of 10 prostate cancer patients, metastasized cancer showed greater uptake in $^{11}C-Acetate$ than $^{18}F-FDG$. In renal cell carcinoma cases, 8 out of 10 patients displayed evidently greater uptake in $^{11}C-Acetate$ than $^{18}F-FDG$. We excluded bladder cancer cases in this study because uptake of $^{18}F-FDG$ in the bladder was too hot, the number of patients was insufficient, and the cases did not meet criteria such as the use of diuretics. Conclusion It is too premature to draw solid conclusions from the survey, since it involved only a small number of participants. However, there are a number of studies conducted abroad that prove the effectiveness of the $^{11}C-Acetate$ PET-CT examinations in treating urinary system cancer, and this study is still ongoing at our hospital. If the tests were to be conducted on a larger number of participants, this study could lead to numerous other potential research topics, such as the correlation between Prostatic specific antigen (PSA) values and $^{11}C-Acetate$ PET-CT, Gleason sum values from biopsy before surgery, Specificity, sensitivity, positive predictive value (PPV), negative predictive value (NPV) between $^{18}F-FDG$ PET-CT examinations and $^{11}C-Acetate$ PET-CT examinations in other urinary system cancers.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.11 no.1
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• pp.110-123
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• 2000

The short-term music therapy was performed for adolescents with conduct disorder admitted to Seoul National Mental Hospital for 3 months from Jun to September, 1998. This case study focused mainly on two female patients who participated regularly in the group music therapy. The music therapy process was divided into three phases；beginning, opening up, and closing. This music therapy session consisted of three parts；hello song as beginning, various musical activities, and sound & movement activity as closing. Free musical improvisation, song discussion, musical monodrama, and sound & movement were the mainly applied techniques. Free improvisation was used to enhance, motivate, identify and contain the adolescents' feelings and ideas. Song discussion was used to convey their thoughts and to support each other. Musical monodrama was used to make them have insights into interpersonal relationships. Sound & movement was used to enhance spontaneity. It made them explore their body and voice as an expressive medium. Throughout three months period of music therapy, patient A's communication skill, socialization, and behavior areas were assessed with improvement. She could use music as a symbolic form and was able to share her feelings about herself and her family. Patient B's self-expression and cognitive areas were assessed with improvement. She became more spontaneous and could verbalize her emotions during the group session. Music as a non-verbal and therefore often a non-threatening medium wherein so much can be expressed provided two female patients an atmosphere where a sense of trust may be regained.

• Economic and Environmental Geology
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• v.51 no.3
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• pp.213-222
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• 2018

Metasediment-hosted Pb-Zn mineralized zone has been found in Dyusembay of Kazakhstan. Its petrological properties, metal index, alteration index and redox-sensitivity are compared with those of SEDEX type deposit. Mineralization is developed along foliation of host rock (graphitic phyllite) and controlled by folds and faults; major ore minerals including pyrite, pyrrhotite, sphalerite, and galena are disseminated or interlayered with fine-grained quartz. The margin of the mineralized zone is metamorphosed accompanying sericite and chlorite. Hydrothermal brecciation and Pb-Zn mineralization formed in quartz-calcite stockworks are confirmed at the around of Maytyubin granitoid intrusions. The mineralization is classified into three types according to those of occurrence, paragenesis, chemical composition and isotopic characteristics. Type 1 whose fine-grained pyrite, pyrrhotite and sphalerite are formed in parallel yet discontinuous to well-developed foliations of the host rock; its geochemistry is similar to those of the earlier stage in SEDEX-type mineralization. In case of type 2, the ore minerals of which are concentrated being parallel to a foliation by regional metamorphism, and most of them associated with quartz and muscovite (${\pm}$ biotite) paragenetically. Type 3 is formed in the hydrothermal breccia zone whose ore minerals are controlled by foliation and breccia and developed in quartz ${\pm}$ calcite veins having a form such as stratification, stockwork or veinlets. Host rocks in the mineralized zone indicate homogeneous metamorphic grade and there is no specific alteration zonation. Also, all types (type 1, type 2, and type 3) represent similar REEs patterns, it can be interpreted that these are originated from a same source. Sulphides occurred in mineralized zone indicate a limited range of sulphur isotope values (type 2, ${\delta}^{34}S=-13.3{\sim}-11.7$‰; type 3, ${\delta}^{34}S=-13.9{\sim}-8.2$‰), and a result of geothermometry presents different temperature ranges: type 2($251{\pm}38^{\circ}C{\sim}277{\pm}40^{\circ}C$); type 3($360{\pm}2^{\circ}C$ to $537{\pm}29^{\circ}C$). It is estimated to be due to the effect of metamorphism and Maytyubin granitoid intrusions, respectively. In addition, ternary chart of thorium, scandium, and zircon for discrimination of tectonic setting and redox sensitivity using V/Mo values indicate that hydrothermal sediments put on reduction environment after precipitation, before being affected by metamorphism and intrusion activity. Geochemical data are plotted on a distal trend of SEDEX-type with discrimination plot using SEDEX index. As a result, petrological-geochemical properties demonstrate that Dyusembay Pb-Zn mineralized zone is comparable to distal-type of SEDEX deposit.