• Geomechanics and Engineering
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• 제8권5호
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• pp.631-647
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• 2015

Engineers may encounter unpredictable cavities, sinkholes and karst conduits while tunneling in karst area, and water inrush disaster frequently occurs and endanger the construction safety, resulting in huge casualties and economic loss. Therefore, an optimal classification method based on grey system theory (GST) is established and applied to accurately predict the occurrence probability of water inrush. Considering the weights of evaluation indices, an improved formula is applied to calculate the grey relational grade. Two evaluation indices systems are proposed for risk assessment of water inrush in design stage and construction stage, respectively, and the evaluation indices are quantitatively graded according to four risk grades. To verify the accuracy and feasibility of optimal classification method, comparisons of the evaluation results derived from the aforementioned method and attribute synthetic evaluation system are made. Furthermore, evaluation of engineering practice is carried through with the Xiakou Tunnel as a case study, and the evaluation result is generally in good agreement with the field-observed result. This risk assessment methodology provides a powerful tool with which engineers can systematically evaluate the risk of water inrush in karst tunnels.

• 터널과지하공간
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• 제15권6호
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• pp.441-451
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• 2005

RMR 암반분류법은 구간별 RMR값 산정시 일정 범위의 값을 채택함으로 인해 불확정성을 피할 수 없다. 이에 본 연구에서는 각 파라미터별로 연속적인 RMR 값을 평가하여 확률밀도함수그래프를 산정하고 모든 경우의 수에 대한 몬테카를로 시뮬레이션과 통계추론을 통해 RMR 산정의 불확정성을 정량적으로 평가하였다. 또한 RMR 산정의 불확정성을 실무에 적용하기 위하여 신뢰수준별 수정 RMR 암반등급 산정표를 제시하였으며, 이를 근간으로 RMR 암반분류의 표준지보패턴 및 지보재 설계 수행절차를 제안하였다.

• Journal of Korean Neurosurgical Society
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• 제58권1호
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• pp.36-42
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• 2015

Objective : Complete sellar floor reconstruction is critical to avoid postoperative cerebrospinal fluid (CSF) leakage during transsphenoidal surgery. Recently, the pedicled nasoseptal flap has undergone many modifications and eventually proved to be valuable and efficient. However, using these nasoseptal flaps in all patients who undergo transsphenoidal surgery, including those who had none or only minor CSF leakage, appears to be overly invasive and time-consuming. Methods : Patients undergoing endoscopic endonasal transsphenoidal tumor surgery within a 5 year-period were reviewed. Since 2009, we classified the intraoperative CSF leakage into grades from 0 to 3. Sellar floor reconstruction was tailored to each leak grade. We did not use any tissue grafts such as abdominal fat and did not include any procedures of CSF diversions such as lumbar drainage. Results : Among 200 cases in 188 patients (147 pituitary adenoma and 41 other pathologies), intraoperative CSF leakage was observed in 27.4% of 197 cases : 14.7% Grade 1, 4.6% Grade 2a, 3.0% Grade 2b, and 5.1% Grade 3. Postoperative CSF leakage was observed in none of the cases. Septal bone buttress was used for Grade 1 to 3 leakages instead of any other foreign materials. Pedicled nasoseptal flap was used for Grades 2b and 3 leakages. Unused septal bones and nasoseptal flaps were repositioned. Conclusion : Modified classification of intraoperative CSF leaks and tailored repair technique in a multilayered fashion using an en-bloc harvested septal bone and vascularized nasoseptal flaps is an effective and reliable method for the prevention of postoperative CSF leaks.

• Asian Pacific Journal of Cancer Prevention
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• 제15권3호
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• pp.1447-1451
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• 2014

Purpose: To compare histopathologic findings of patients who underwent transurethral resection of a bladder tumor (TUR-B) between groups with and without the metabolic syndrome. Materials and Methods: We retrospectively analyzed data of 535 patients who underwent TUR-B in our department between October 2005 and March 2011. All patients had primary urethelial cell carcinoma (UCB). Histologic stage, grade, the presence of hypertension, diabetes mellitus, body mass index (BMI), waist circumference, HDL and trigliseride levels were evaluated. The TNM classification was used, with Ta tumor accepted as lower stage and T1 and T2 tumors as higher stage bladder cancers. Also, the pathological grading adopted by the 2004 World Health Organization grading system were applied. Non-invasive papillary urothelial neoplasms of low malignant potential were regarded as low grade. Results: Among the total of 509 patients analyzed in our study, there were 439 males (86.2%) and 70 females (13.8%). Metabolic syndrome was significantly associated with high histologic grade, and high pathologic stage (p<0.001). Conclusions: The patients with metabolic syndrome were found to have statistically significant higher T stage and grade of bladder cancer. Further studies with more patients are needed to confirm our study.

• Journal of Preventive Medicine and Public Health
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• 제10권1호
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• pp.52-58
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• 1977

By evaluating the health status by Cornell Medical Index in conjunction with their academic grade, we attempted to find out whether any health condition may affect on their academic carrier. CMI health questionnaire was filled out by student and matched with one's own academic score if the previous year. Academic score was classified into 5 grades: excellent, very good, good, fair and poor. Difference in number of questions between sections was corrected by standard score method with means of 50 and standard deviation of 10. Differences in number of 'yes' answers between sections and between groups of students in each grade were statistically tested by two-way variance analysis method. On the other hand, influence of neuropsychiatric factors (section M-R) on the academic carrier was analyzed by $X^2-test$ with Fukamachi's classification. The following were the results obtained in this study: 1) Number of 'yes' answers in sections related to mood and feeling patterns (sections M-R) were appeared to be influential to academic carrier in male students, but not in female students. 2) Generally speaking, in groups of higher academic grade, number of 'yes' answers in each section was on an averege 50 or less, and in groups of lower academic grade, the number was 50 or more depending on sections. 3) Number of 'yes' answers between sections and between groups in each academic grade were significantly different both in male and female college students. 4) It was noteworthy that data obtained from CMI questionnaire might be variable subjectively by examinees with some factors at the time of administration.

• Asian Pacific Journal of Cancer Prevention
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• 제16권10호
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• pp.4377-4381
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• 2015

Background: Gastroenteropancreatic neuroendocrine tumors (GNs) are slow growing and although their incidence has increased in recent years, they are relatively rarely seen. Somatostatin analogues are used in the treatment of GNs that express somatostatin receptor (SR). We aimed to investigate the expression of SR2 and SR5 in GNs. Materials and Methods: In this study the expression of SR2 and SR5 was investigated immunohistochemically in 49 cases (26 males, 23 females) diagnosed and graded with GN according to the World Health Organization classification 2010. Results: The percentage of SR2 staining was 91.0% in grade 1, 82.8% in grade 2 and 100% in grade 3. On the other hand, the percentage of SR5 staining was 81.8% % in grade 1, 60.0% in grade 2 and 0% in grade 3. According to the tumor localization, the percentages of SR2 expression were as follows: pancreas 85.7%, stomach 100%, small bowel 70%, appendix 85.7% and rectum 100%. The percentages of SR5 expression were: pancreas 61,9%, stomach 37.5%, small bowel 70%, appendix 71.5% and rectum 66.6%. There was a significant negative correlation between ki67 percentage and SR5 expression (r=-0.341, p=0.016). Conclusions: In this study, GNs were found to highly express SR2 and SR5. Although the expression of SR2 and SR5 changed according to tumor localization, the expression of SR2 was higher than the expression of SR5 in GN. There was a significant negative correlation between ki67 and SR5. Accordingly, SR5 may be a prognostic indicator of GN.

• Journal of Korean Neurosurgical Society
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• 제30권7호
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• pp.855-860
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• 2001

Introduction : It has been reported that the survival of low-grade glioma patients depends upon the time of malignant transformation. The authors presents the clinical analysis of histologically proven trasformed gliomas. Materials and Method : A total 92 patients who were consecutively treated and histologically confirmed hemispheric low-grade gliomas between 1980 and 1998 were analyzed and followed. All cases meet the criteria of WHO glioma classification of grade II. Results : The mean follow-up period was 73 months. Twenty two among 92 cases(24%) were histologically proven to be transformed into malignant ones. The mean time to transformation was 56 months. The 5-year and 10-year survival rates of the transformed group were 66% and 30% respectively and significantly different from the survival rates of the non-transformed group(p=0.0018). Among clinical factors at presentation, the initial tumor volume had a tendency to be larger in the transformed group than that of the non-transformed group and became significant when it was divided into more than $30cm^3$ or not(p=0.02). Among therapeutic factors, the extent of removal had no influence on the rate of malignant transformation. But postoperative radiation therapy were more frequently given to the pre-transformed group than the non-transformed group and the frequency was significantly different(p=0.02). Conclusions : The authors had found that the initial tumor volume and radiation therapy could be clinical prognostic factors for the malignant transformation of low-grade gliomas.

• East Asian mathematical journal
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• 제34권4호
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• pp.371-402
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• 2018

The researchers set up a research question to find out how to teach the concept of a right triangle through classification activities after listening to the conversations of fellow teachers about the recently revised textbooks. First, a questionnaire was created to confirm the objectivity of the research problem, data were collected through online and offline, and interviews were conducted with some of the respondents. As a result, it confirmed that there was a considerable difference in the perception of the research study about the direction of revising the curriculum called 'student participation centered' and 'the possibility of achieving the learning objective'. Then, we analyzed the critical interpretations used in the third grade math textbook Lesson 2. 'Plane Figure' part 4 and 5. Finally, by analyzing the results of the recognition analysis and textbook analysis, we proposed two learning methods which can link the triangle classification activity and the right triangle concept. Based on the results of the research, we obtained suggestions that a teaching should be made regarding that the classification process may be changed according to the student's prior knowledge and the process of classification activities may be different according to the viewpoint and classification criteria.

• 한국초등과학교육학회지:초등과학교육
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• 제26권1호
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• pp.41-48
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• 2007

The purpose of this study is to examine how many plant names elementary school children how, and what kind of criteria they use for classifying these plants. The sample involved 926 students from the 2nd, the 4th, and the 6th grades dwelling in one urban, three suburban, and six rural areas. Their level of perception on the name of plants increased in correlation to the elevation of the grade level. However, different patterns of increases were shown depending on the local environments in which they live. The most well-known plant names for students were the rose of Sharon, the rose and the pine tree. The students mostly classified the plants using the following criteria such as 'with or without flower' and 'edible or inedible' regardless as to whether they had prior loaming experience of plant classification. 65.3% of the 6th graders correctly grouped 5 kinds of plants into the flowering and the non-flowering plant categories at the 1st level of classification. However, only 17.9% and 7.7% correctly divided the flowering and the non-flowering plants into two subgroups at the 2nd level of classification respectively. Therefore, their abilities in plant classification was shown overall to be poor. The students living in suburban areas appeared to be harmonized with both the natural and urbanized surroundings and classified the plants more scientifically than those from the urban or rural areas were able to. This suggests that the conception of plant classification by children is affected by the environment in which they live. If children have more opportunities to observe plants in surroundings such as their classrooms and school gardens, it will help them to form the relevant scientific concepts as well as to correct any alternative conceptions related to classification.

• 정보처리학회논문지B
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• 제11B권2호
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• pp.159-168
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• 2004

본 논문에서는 위성영상의 분류에 대한 성능 개선을 위하여 ISODATA 클러스터링, 퍼지 C-Means 알고리즘, 베이시안 최대우도 분류기법을 통합한 하이브리드 분류기법을 제안하였다. 본 연구에서는 분석자에 의하여 분류항목별 학습 데이터를 선정한 후 이를 ISODATA 클러스터링을 이용하여 각각의 분류항목별로 분광특징에 따라 학습 데이터를 세분화하여 새로운 학습 데이터를 선정하였다. 새롭게 선정된 학습 데이터를 이용하여 퍼지 C-Means 알고리즘을 이용하여 분류를 수행하고 그 결과를 베이시안 최대우도 분류기의 사전확률로 적용하여 분류를 수행하였다. 그 결과 분석자가 선정한 분류항목별 훈련데이터의 분광적인 특징에 관계없이 분류를 수행할 수 있었으며 위성영상의 분류의 성능을 개선할 수 있었다. 제안된 기법은 Landsat TM 위성영상을 이용하여 그 적용성을 시험하였다.