• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.3
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• pp.20-38
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• 2014

Vegetation phenology is the most important indicator of ecosystem response to climate change. Therefore it is necessary to continuously monitor forest phenology. This paper analyzes the phenological characteristics of forests in South Korea using the MODIS vegetation index with error from clouds or other sources removed using the HANTS algorithm. After using the HANTS algorithm to reduce the noise of the satellite-based vegetation index data, we were able to confirm that phenological transition dates varied strongly with altitudinal gradients. The dates of the start of the growing season, end of the growing season and the length of the growing season were estimated to vary by +0.71day/100m, -1.33day/100m and -2.04day/100m in needleleaf forests, +1.50day/100m, -1.54day/100m and -3.04day/100m in broadleaf forests, +1.39day/100m, -2.04day/100m and -3.43day/100m in mixed forests. We found a linear pattern of variation in response to altitudinal gradients that was related to air temperature. We also found that broadleaf forests are more sensitive to temperature changes compared to needleleaf forests.

• Investigative Magnetic Resonance Imaging
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• v.8 no.1
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• pp.1-8
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• 2004

Purpose : Information about electrical activity inside the brain during fMRl scans is very useful in monitoring physiological function of the patient or locating the spatial position of the activated region in the brain. However, many additional noises appear in the EEG signal acquired during the MRI scan. Gradient induced noise is the biggest one among the noises. In this work, we propose a gradient noise reduction method using the independent component analysis (ICA) method. Materials and Methods : We used a 29-channel MR-compatible EEG measurement system and a 3.0 Tesla MRI system. We measured EEG signals on a subject lying inside the magnet during EPI scans. We selectively removed the gradient noise from the measured EEG signal using the ICA method. We compared the results with the ones obtained with conventional averaging method and PCA method. Results : All the noise reduction methods including the averaging and PCA methods were effective in removing the noise in some extent. However, the proposed ICA method was found to be superior to the other methods. Conclusion : Gradient noise in EEG signals acquired during fMRI scans can be effectively reduced by the ICA method. The noise-reduced EEG signal can be used in fMRI studies of epileptic patients or combinatory studies of fMRI and EEG.

• Cartoon and Animation Studies
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• s.10
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• pp.1-16
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• 2006

This thesis aims to recall the importance of language in comics by studying comic strips in Korean daily newspapers: the comic strips are analyzed for rhetorical puns in its language text as they representatively show the value and role of language in comics. Moreover, Korean comic strips, as they developed into current affairs comics, acquired a stronger media characteristic of communicating information compared to other genres of cartoons. As a result, comics strips have become a genre where language plays an important role and the words needing to be able to convey the meaning quickly and implicitly. Due to tight control of national authority, the language technique developed into an indirect expression rather than a stronger direct imaging technique. The political oppression of the comic strip paradoxically brought on the rhetorical development in the creative techniques. Based on this analysis, the writer studied the rhetorical puns of the texts Korean comic strips by implementing the classification techniques of rhetoric expressions. As a result, through quotes and analysis of actual comic strips, the writer confirmed that Korean comic strips do actually show tremendously vast rhetorical puns in its language application techniques. The writer was also able to conclude that the rhetorical puns in comics were the force entertaining and impressing the readers, and also acting as the creative principle. Concluding this study, the writer emphasizes that language, not only in comic strips, is a combination of words and images and is also an important factor in all cartoons in general. Thus the thesis proposes that the training of humanistic thoughts and linguistic sensitivity are as important as learning to draw in the creation of cartoons.

• Progress in Medical Physics
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• v.19 no.3
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• pp.178-185
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• 2008

Living donor liver transplantation is increasingly performed as an alternative to cadaveric transplantation. Preoperative screening of the donor candidates is very important. The quality, size, and vascular and biliary anatomy of the liver are best assessed with magnetic resonance (MR) imaging or computed tomography (CT). In particular, the volume of the potential graft must be measured to ensure sufficient liver function after surgery. Preoperative liver segmentation has proved useful for measuring the graft volume before living donor liver transplantations in previous studies. In these studies, the liver segments were manually delineated on each image section. The delineated areas were multiplied by the section thickness to obtain volumes and summed to obtain the total volume of the liver segments. This process is tedious and time consuming. To compensate for this problem, automatic segmentation techniques have been proposed with multiplanar CT images. These methods involve the use of sequences of thresholding, morphologic operations (ie, mathematic operations, such as image dilation, erosion, opening, and closing, that are based on shape), and 3D region growing methods. These techniques are complex but require a few computation times. We made a phantom for volume measurement with pig and evaluated actual volume of spleen and liver of phantom. The results represent that our semiautomatic volume measurement algorithm shows a good accuracy and repeatability with actual volume of phantom and possibility for clinical use to assist physician as a measuring tool.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.1
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• pp.48-54
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• 2009

Purpose: There are few studies evaluating the usefulness of dedicated high-resolution scintimammography and no studies using delayed washout with this dedicated high resolution scintimammography for the evaluation of breast lesions. We underwent this study to evaluate the clinical usefulness of Tc-99m MIBI in evaluating patients with palpable breast lesions using dedicated high-resolution scintimammography. Materials and Methods: This study included 19 patients with 23 palpable breast lesions who underwent mammography. Tc-99m MIBI was taken to further characterize these lesions. Scintimammography images were acquired with standard craniocaudal and mediolateral oblique views and delayed images were additionally taken. Final conclusions were based on histopathology, either by biopsy or mastectomy results. Results: Eighteen lesions were malignant and five were benign. Mammography was indeterminate for thirteen lesions, nine of those were malignant. Mammography also categorized one lesion as benign in a dense breast, but scintimammography and pathology results showed malignancy. Of the five benign lesions, two were visible on scintimammography, but delayed images showed washout. Conclusion: Based on our preliminary results, dedicated high resolution scintimammography seems to be very useful in characterizing palpable lesions that were indeterminate or negative on mammography.

• Journal of Gifted/Talented Education
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• v.23 no.5
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• pp.637-648
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• 2013

The relationship between the cerebral cortex and human intelligence has been studied using various methods, and related brain areas involved in intellectual manifestation have been discovered individually. Such studies have also shown the cerebellum is closely involved in various cognitive functions such as language, memory, and information processing. However, studies showing an activity difference between the cerebral cortex and cerebellum when performing specific tasks are hard to find. This study searched and analyzed the active regions of the cerebral cortex and cerebellum seen while performing the inference of geometrical figures. A WAIS intelligence test was conducted using 81 healthy boys (16.3 years of age on average), and five categories were classified. While performing the inference of shapes, their brain images were taken using functional magnetic resonance imaging (fMRI). As a result, the activity in 12 brain regions was observed, including in the cerebral cortex, the bilateral inferior parietal, the visual cortex, bilateral superior parietal, frontal-Inf-Tri-R, and bilateral caudate, while activities in 5 discrete areas were seen in the cerebellum. In particular, the higher the intelligence (IQ) of the subject, the stronger their activity. Among those with the most superior intelligence, subjects with an IQ of 140-147 showed significantly higher activity compared to the other groups. Such results seem to represent a very high utilization of intelligence in a highly gifted group, and we can expect to use this to determine the super gifted.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6705-6709
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• 2015

Background: Venous thromboembolisms (VTEs) constitute a group of diseases including deep vein thrombosis (DVT) and pulmonary embolism (PE). They regarded as the second leading cause of death in cancer patients and several studies have confirmed that VTEs have a negative impact on survival and recurrent rate in both ovarian and endometrial cancer cases. The incidence of VTEs differs worldwide and depends on several risk factors including race, underlying disease, lifestyle, body weight, BMI and genetic risk factors. There is heterogeneity of DVT rates between Asian and Western countries. This study was conducted in order to evaluate the character and incidence of VTEs in gynecologic oncology patients in King Chulalongkorn Memorial Hospital over a 10 year period. Materials and Methods: A retrospective chart review was performed with VTEs defined as objective diagnosis of acute DVT or PE with typical symptoms and signs. Diagnoses were approved byan internist and/or confirmed with imaging studies. Data from both outpatient and inpatient sessions of the affected cases from January 2004 to December 2013 were extracted. General characteristics of the patients were collected with details of the diseases, types of cancer, stage, date of diagnosis of cancer, operative data, treatment outcome, progression free survival and overall survival. Results: Thirty cases of VTEs were identified in a total 2,316 gynecologic oncology cases. The incidence of symptomatic VTEs in total gynecologic oncology patients in our institution is 1.295%. The incidence of VTEs in ovarian cancer patients in our institution was 5.9%. Duration for VTE detection ranged from 13 months before diagnosis of cancer to 33 months after diagnosis of cancer. Most of the VTE cases were detected in ovarian cancer patients (60%). The most common cell type was adenocarcinoma (moderately to poorly differentiated) which accounted for 26.7% of the cases. The second most common cell type was clear cell carcinoma with 23.3% of the cases. Thirty percent of VTE cases developed before cancer was diagnosed, 20% were diagnosed at the same time as cancer detection and fifty percent developed after cancer was diagnosed. Median disease free survival of the gynecologic oncology patients with VTE was 7.5 months. Median overall survival (OS) was 12 months. Median progession free survivals of DVT and PE groups were 11.5 and 5.5 months, respectively. OS of DVT and PE was 12.0 and 11.5 months respectively. Conclusions: The incidence of VTE in Asian countries is believed to be lower than in European or Western countries. From our retrospective review, the incidence of VTEs in all types of gynecologic oncology was 1.295%, much lower than reported in the West. The reason for the lower incidence may genetic differences. Another factor is that VTE in this review was symptomatic, which is less than asymptomatic VTE. More than half of VTEs in this study developed in ovarian cancer patients. The results are compatible with earlier reports that among gynecologic malignancies, the incidence of VTE is highest in ovarian cancer.

• Journal of Ginseng Research
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• v.40 no.2
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• pp.160-168
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• 2016

Background: Ginseng (Panax ginseng Meyer) is a well-characterized medicinal herb listed in the classic oriental herbal dictionary as "Shin-nong-bon-cho-kyung." Ginseng has diverse pharmacologic and therapeutic properties. Black ginseng (BG, Ginseng Radix nigra) is produced by repeatedly steaming fresh ginseng nine times. Studies of BG have shown that prolonged heat treatment enhances the antioxidant activity with increased radical scavenging activity. Several recent studies have showed the effects of BG on increased lipid profiles in mice. In this study report the effects of water and ethanol extracts of BG on hypercholesterolemia in rats. To our knowledge, this is the first time such an effect has been reported. Methods: Experiments were conducted on male Sprague Dawley rats fed with a high-cholesterol diet supplemented with the water and ethanol extracts of BG (200 mg/kg). Their blood cholesterol levels, serum white blood cell levels, and cholesterol-metabolizing marker genes messenger RNA (mRNA) expression were determined. Liver and adipose tissues were histologically analyzed. Results: We found that BG extracts efficiently reduced the total serum cholesterol levels, low-density lipoprotein (LDL) levels with increased food efficiency ratio and increased number of neutrophil cells. It also attenuated the key genes responsible for lipogenesis, that is, acetyl-coenzyme A (CoA) acetyltransferase 2, 3-hydroxy-3-methyl-glutaryl-CoA reductase, and sterol regulatory element-binding protein 2, at the mRNA level inside liver cells. Furthermore, the BG extract also reduced the accumulation of fat in adipose tissues, and inhibited the neutral fat content in liver cells stained with hematoxylin and eosin and oil red O. Conclusion: Administration of BG extracts to Sprague Dawley rats fed with high-cholesterol diet ameliorated hypercholesterolemia, which was mediated via modulation of cholesterol-metabolizing marker genes. This data throw a light on BG's cardioprotective effects.

• Journal of Yeungnam Medical Science
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• v.23 no.2
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• pp.171-181
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• 2006

Background: $Clonorchis$ $sinensis$ is an important human parasite that is usually found in the biliary tract. It is widely distributed in East Asia in Taiwan, Japan, China and Korea. About 2 million people are estimated to be infected with $C.$ $sinensis$ in Korea. This study was conducted to evaluate the state of infestation and clinical aspects of $C.$ $sinensis$. Material and Methods: We evaluate 1,063 patients with clonorchiasis retrospectively at Yeungnam University Hospital and Health Promotion Center from January 2001 to December 2003. All patients were diagnosed by a positive stool test for $C.$ $sinensis$ eggs. Clinical features, laboratory data and imaging studies were evaluated. Results: The ratio between affected males and females was 3.6 : 1. The highest infection rate was noted in the 40-60 age groups regardless of sex. The infection rate of $C.$ $sinensis$ among the residents of urban areas was higher than in rural areas. There were 813 (76.5%) patients who were asymptomatic. Common symptoms included right upper abdominal pain in 7.6% and epigastric pain in 7.2%. For the laboratory studies, serum ALP and GGT levels were within normal limits in 85.2% and 56.0% respectively. Peripheral eosinophilia was noted in 66.1% of cases. Of the 83 cases undergoing ERCP, 27 cases (32.5%) showed peripheral dilatation of the intrahepatic duct. Conclusion: This study suggests that $C.$ $sinensis$ infection is still endemic even in rural areas of Korea and that asymptomatic infections are common. Further work should be focused on the early diagnosis and treatment of patients with subclinical infection.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3525-3531
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• 2014

Objective: Fluorine-18-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) is a new technique for identifying different malignant tumors using different uptake values between tumor cells and normal tissues. Here we assessed the diagnostic accuracy of 18F-FDG-PET in patients with testicular cancer by pooling data of existing trials in a meta-analysis. Methods: PubMed/MEDLINE, Embase and Cochrane Central Trials databases were searched and studies published in English relating to the diagnostic value of FDG-PET for testicular cancer were collected. The summary receiver operating characteristic (SROC) curve was used to examine the FDG-PET accuracy. Results: A total of 16 studies which included 957 examinations in 807 patients (median age, 31.1 years) were analyzed. A meta-analysis was performed to combine the sensitivity and specificity and their 95% confidence intervals (CIs), from diagnostic odds ratio (DOR), positive likelihood ratios (PLR), negative likelihood ratio (NLR). SROC were derived to demonstrate the diagnostic accuracy of FDG-PET for testicular cancer. The pooled sensitivity and specificity were 0.75 (95% confidence interval (CI), 0.70-0.80) and 0.87 (95% CI, 0.84-0.89), respectively. The pooled DOR was 35.6 (95% CI, 12.9-98.3). The area under the curve (AUC) was 0.88. The pooled PLR and pooled NLR were 7.80 (95% CI, 3.73-16.3) and 0.31 (95% CI, 0.23-0.43), respectively. Conclusion: In patients with testicular cancer, 18F-FDG-PET demonstrated a high SROC area, and could be a potentially useful tool if combined with other imaging methods such as MRI and CT. Nevertheless, the literature focusing on the use of 18F-FDG-PET in this setting still remains limited.