• Korean Journal of Environment and Ecology
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• v.33 no.4
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• pp.378-401
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• 2019

This study generated a list of plants in eight sections from the Baekdansa ticket office (874m) to Cheonjedan (1,560m) divided in the interval of 100m above sea level to examine the species diversity patterns and distribution changes of the vascular plants at different altitudes in Taebaeksan National Park. Four site surveys found a total of 385 taxa: 89 families, 240 genera, 345 species, 5 subspecies, 34 varieties, and 1 form. A result of analyzing the change of species diversity along elevational gradients showed that it decreased with increasing elevation and then increased from a certain section. A result of analyzing habitat affinity types showed that the proportion of forest species increased with increasing elevation. On the other hand, the ruderal species appeared at a high rate in the artificial interference section. A result of comparing the proportion of woody and herb plants showed that the woody plants gradually increased with elevation and rapidly decreased in the artificial interference section. On the other hand, the herb plants showed the opposite trend. A result of analyzing the change of distribution of species according to altitude with the DCA technique showed that the vascular plants were divided into three groups according to the elevation in order on the I axis with the boundaries at 900m and 1,300m above sea level. The arrangement of each stand from right to left along the altitude on the I axis with a significant correlation with warmth index (WI) confirmed that the temperature change along the altitude could affect the distribution of vascular plants, composition, and diversity. Therefore, the continuous monitoring is necessary to confirm ecological and environmental characteristics of vegetation, distribution ranges, changes of habitat. We expect that the results of this study will be used as the basic data for establishing the measurement measures related to the preservation of biodiversity and climate change.

• Journal of Gastric Cancer
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• v.8 no.3
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• pp.129-135
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• 2008

Purpose: The usefulness of serum tumor markers for assessing gastric carcinoma is very limited compared to that for neoplasms in other digestive organs. Many reports have shown that serum tumor markers are closely associated with the prognosis and tumor recurrence in gastric cancer patients. However, little is known about the usefulness of serum tumor markers as a predictor of distant metastasis for gastric carcinoma. Materials and Methods: With excluding the non-specific causes of elevated tumor markers, a total of 788 patients with gastric carcinoma and who were seen at our hospitals between 2004 and 2006 were included in this study. The correlation between the preoperative level of tumor makers and the clinicopathological features was analyzed. Results: CEA was significantly correlated with age, gender and nodal metastasis, but not with the depth of tumor. The CEA level was not correlated with distant metastasis, such as peritoneal or hematogenous metastasis. In contrast, the CA 19-9 level was significantly correlated not only with the depth of tumor and nodal metastasis, but also with peritoneal metastasis. Especially, the patients with over 500% elevation of the CA 19-9 level had a significant risk of peritoneal metastasis. Conclusion: CA 19-9 is useful for predicting peritoneal metastasis in gastric cancer patients. It can be used efficiently in making the diagnostic and the treatment plan, in combination with other diagnostic tools, for gastric cancer patients.

• Sleep Medicine and Psychophysiology
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• v.28 no.2
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• pp.78-85
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• 2021

Objectives: When elderly patients show depressive symptoms, discrimination between depressive disorder and prodromal phase of Alzheimer's disease is important. We tested whether a quantitative electroencephalogram (qEEG) marker was associated with cerebral amyloid-β (Aβ) deposition in older adults with depression. Methods: Non-demented older individuals (≥ 55years) diagnosed with depression were included in the analyses (n = 63; 76.2% female; mean age ± standard deviation 73.7 ± 6.87 years). The participants were divided into Aβ+ (n = 32) and Aβ- (n = 31) groups based on amyloid PET assessment. EEG was recorded during the 7min eye-closed (EC) phase and 3min eye-open (EO) phase, and all EEG data were analyzed using Fourier transform spectral analysis. We tested interaction effects among Aβ positivity, condition (EC vs. EO), laterality (left, midline, or right), and polarity (frontal, central, or posterior) for EEG alpha band power. Then, the EC-to-EO alpha reactivity index (ARI) was examined as a neurophysiological marker for predicting Aβ+ in depressed older adults. Results: The mean power spectral density of the alpha band in EO phase showed a significant difference between the Aβ+ and Aβ- groups (F = 6.258, p = 0.015). A significant 3-way interaction was observed among Aβ positivity, condition, and laterality on alpha-band power after adjusting for age, sex, educational years, global cognitive function, medication use, and white matter hyperintensities on MRI (F = 3.720, p = 0.030). However, post-hoc analyses showed no significant difference in ARI according to Aβ status in any regions of interest. Conclusion: Among older adults with depression, increased power in EO phase alpha band was associated with Aβ positivity. However, EC-to-EO ARI was not confirmed as a predictor for Aβ+ in depressed older individuals. Future studies with larger samples are needed to confirm our results.

• Journal of Intelligence and Information Systems
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• v.29 no.2
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• pp.101-114
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• 2023

In the wartime, aircraft carrying out a mission to strike the enemy deep in the depth are exposed to the risk of being shoot down. As a key combat force in mordern warfare, it takes a lot of time, effot and national budget to train military flight personnel who operate high-tech weapon systems. Therefore, this study studied the path problem of predicting the route of emergency escape from enemy territory to the target point to avoid obstacles, and through this, the possibility of safe recovery of emergency escape military flight personnel was increased. based problem, transforming the problem into a TSP, VRP, and Dijkstra algorithm, and approaching it with an optimization technique. However, if this problem is approached in a network problem, it is difficult to reflect the dynamic factors and uncertainties of the battlefield environment that military flight personnel in distress will face. So, MDP suitable for modeling dynamic environments was applied and studied. In addition, GIS was used to obtain topographic information data, and in the process of designing the reward structure of MDP, topographic information was reflected in more detail so that the model could be more realistic than previous studies. In this study, value iteration algorithms and deterministic methods were used to derive a path that allows the military flight personnel in distress to move to the shortest distance while making the most of the topographical advantages. In addition, it was intended to add the reality of the model by adding actual topographic information and obstacles that the military flight personnel in distress can meet in the process of escape and escape. Through this, it was possible to predict through which route the military flight personnel would escape and escape in the actual situation. The model presented in this study can be applied to various operational situations through redesign of the reward structure. In actual situations, decision support based on scientific techniques that reflect various factors in predicting the escape route of the military flight personnel in distress and conducting combat search and rescue operations will be possible.

• Clinical and Experimental Pediatrics
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• v.48 no.3
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• pp.266-275
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• 2005

Purpose : Acute respiratory tract infections are the most common illnesses in children. The great majority of these infections involving lower respiratory tracts infections(LRTIs) are caused by respiratory viruses such as respiratory syncytial virus(RSV), parainfluenza virus(PIV), influenza virus (Flu), and adenovirus(ADV), etc. Our purpose was to determine seasonal epidemiology and clinical characteristic features of each viral infection. Methods : Nasopharyngeal aspirate(NPA)s were collected from 4,554 hospitalized children diagnosed as LRTIs on the first day of admission. The study period was from September 1998(Autumn) through May 2003(Spring). Respiratory viruses were detected in 881(19 percent) cases by isolation of the virus or by antigen detection method using indirect immunofluorescent staining. We reviewed the medical records of 837 cases retrospectively. Results : The identified pathogens were RSV in 485 cases(55 percent), PIV in 152 cases(17 percent), FluA in 114 cases(13 percent), ADV in 79 cases(9 percent) and FluB in 51 cases(6 percent). Outbreaks of RSV occurred every year, mostly in the November through December period and of PIV in the April through June period. LRTIs by FluA reached the highest level in January, 2002. FluB infection showed an outbreak in April, 2002. The clinical diagnoses of viral LRTIs were bronchiolitis in 395 cases(47 percent), pneumonia in 305 cases(36 percent), croup in 73 cases(9 percent) and tracheobronchitis in 64 cases(8 percent). Conclusion : Viruses are one of the major etiologic agents of acute LRTIs in chidren. Therefore, we must continue to study their seasonal occurrence and clinical features to focus on management, and also for reasons of prevention.

• Journal of The Korean Association For Science Education
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• v.23 no.3
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• pp.286-298
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• 2003

The purpose of this study was to analyze scientific thinking types and processes generated in inductive inquiry by college students. Subjects were three college student. Three inductive tasks were developed: Caminalcules set I which is a task consisted of 6 imaginary animals, a potato task which is a task about the interaction between juiced potato and $H_2O_2$, and Caminalcules set 2. Subjects' thinking types and processes were investigated through thinking-aloud method and interview. Subjects' performances were recorded on videotapes and analyzed. Subjects have shown 5 types of inductive thinking in the first task; observing, discovering commonness, discovering pattern, classifying, discovering hierarchy. The processes of inductive thinking shown by students are followed; observing $\rightarrow$discovering commonness $\rightarrow$classifying $\rightarrow$discovering pattern $\rightarrow$discovering hierachy. The subtypes of inductive thinking on observing were investigated by the analysis of subjects' performance on the second task. In analysis of protocol, student' thinking types on observing have been classified as simple observing and operational observing. Operational observing has been categorized conjectural observing and predictive observing. The subtypes of inductive thinking on classification and hierarchy were investigated by the analysis of subjects' performance on the third task. In analysis of protocol, students' thinking types on classification have been searching criteria for classifying and selecting criteria for classifying. Subtypes of discovering hierarchy have been classifying groups and hierarchical ordering by students. Processes of classifying groups proceeded from searching criteria for classifying to selecting criteria for classifying.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.6
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• pp.444-450
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• 2008

Purpose: The aim of this study was to evaluate the usefulness of whole body positron emission tomography (PET) using $^{18}F-fluorodeoxyglucose$ ($^{18}F-FDG$) for cancer screening in asymptomatic subjects. Materials and Methods: The subjects were 1,762 men and 259 women who voluntarily underwent $^{18}F-FDG$ PET for cancer screening as a part of a routine health examination. Final diagnosis was decided by other diagnostic studies, pathological results or clinical follow-up for 1 year. Results: Of 2,021 subjects, 40 (2.0%) were finally proved to have cancer. Abnormal focal $^{18}F-FDG$ uptake suggesting malignancy was found in 102 subjects (5.0%). Among them, 21 subjects (1.0%) were proved to have cancer. Other tests in the routine health examination could not find 9 of 21 cancers (42.9%) detected by PET. The sensitivity, specificity, positive predictive value, and negative predictive value of PET for cancer screening were 52.5%, 95.9%, 20.6%, and 99.0%, respectively. Pathologies of cancers missed on PET were adenocarcinoma (n = 9; 3 colon cancers, 3 prostate cancers, 2 stomach cancers, and 1 rectal cancer), differentiated thyroid carcinoma (n = 6), bronchioalveolar cell carcinoma (n = 2), urinary bladder cancer (n = 1), and melanoma (n = 1). More than half of cancers which were not detected by PET were smaller than 1 cm in diameter. Conclusion: $^{18}F-FDG$ PET might be useful for cancer screening in asymptomatic subjects due to its high specificity and negative predictive value and playa supplementary role to the conventional health check-up, but it could not replace due to limited sensitivity for urological cancers, small-sized tumors and some hypometaboic cancers.

• Journal of Food Hygiene and Safety
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• v.32 no.1
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• pp.8-13
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• 2017

This study was conducted to develop an agent-based computing platform enabling simulation of on-farm produce contamination by enteric foodborne pathogens, which is herein called PPMCS (Preharvest Produce Microbial Contamination Simulator). Also, fecal contamination of preharvest produce was simulated using PPMCS. Although Agent-based Modeling and Simulation, the tool applied in this study, is rather popular in where socio-economical human behaviors or ecological fate of animals in their niche are to be predicted, the incidence of on-farm produce contamination which are thought to be sporadic has never been simulated using this tool. The agents in PPMCS including crop, animal as a source of fecal contamination, and fly as a vector spreading the fecal contamination are given their intrinsic behaviors that are set to be executed at certain probability. Once all these agents are on-set following the intrinsic behavioral rules, consequences as the sum of all the behaviors in the system can be monitored real-time. When fecal contamination of preharvest produce was simulated in PPMCS as numbers of animals, flies, and initially contaminated plants change, the number of animals intruding cropping area affected most on the number of contaminated plants at harvest. For further application, the behaviors and variables of the agents are adjustable depending on user's own scenario of interest. This feature allows PPMCS to be utilized in where different simulating conditions are tested.

• Investigative Magnetic Resonance Imaging
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• v.18 no.2
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• pp.133-143
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• 2014

Purpose : The aim of this study was to determine the magnetic resonance imaging (MRI) features associated with re-excision due to the presence of a positive margin after breast conserving therapy (BCT) in breast cancer patients. Materials and Methods: We reviewed the records of 286 consecutive breast cancer patients who received BCT between January 2006 and December 2007. Among 246 patients who had undergone BCT, 38 (15.4%) underwent immediate further surgery due to positive margin status. We analyzed the MRI findings using ${\chi}^2$ test, Fisher's exact test and t tests. Multivariate logistic regression was conducted for prediction of re-excision. Results: Tumor size (p < 0.001), lesion multiplicity (p = 0.003), and non-mass-like enhancement (NMLE) type on MRI (p < 0.001) were associated with margin involvement in BCT. On preoperative MRI, larger size (${\geq}5cm$) (odds ratio = 2.96), NMLE (odds ratio = 3.81), and multifocal lesions (odds ratio = 2.54) were positively associated with re-excision. In cases involving NMLE, segmental distribution was associated with a greater likelihood of immediate re-excision. Conclusion: Larger size, multiplicity, and NMLE on MRI are significantly associated with re-excision after BCT in breast cancer patients. For NMLE lesions, the segmental distribution pattern was predictive of re-excision.

• Journal of Chest Surgery
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• v.37 no.8
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• pp.672-683
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• 2004

Background: The treatment results of the advanced lung carcinoma is not satisfactory with the present therapeutic modalities: surgical resection, anti-cancer chemotherapy, and radiotherapy or combination therapy. To predict the prognosis of the non-small-cell lung carcinoma, TNM classification has been was as the basic categorization; however, it has been not satisfactory. It is necessary to consider the causes and the prognosis of the lung carcinoma from another points of view rather the conventional methods. We intended to find out the relationship between the major apoptotic factor, p53 gene and the prognosis of the patient with lung carcinoma. Material and Method: Three hundreds and fifty-nine patients with lung carcinoma who underwent surgery were analysed. We observed p53 protein accumulated in the cellular nuclei. The p53 protein was detected by immuno-histo-chemical method. We collected information of the patient retrospectively. Result: p53 protein densities were observed in 40% in average as a whole. The protein density was 44 percent in man, 25 percent in woman, 49 percent in the squamous cell carcinoma, and 38 percent in the adenocarcinoma. There were significant correlations between the p53 protein density and the mortality in the squamous cell carcinoma (p=0.025), follow-up duration in TNM stage I group (p=0.010), and follow-up duration in the lobectomy patient group (p=0.043), and tumor cell differentiation (p=0.009). p53 protein densities were significantly different between the lobectomy and the pneumonectomy group (p=0.044). Conclusion: The authors found that p53 protein had some correlations with the prognosis of the lung cancer partially in some factors. We suggest the p53 protein density could be used as a marker of prognosis in the non-small-cell lung carcinoma.