• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.4
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• pp.605-610
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• 2013

A cryptography for enforcing hierarchic groups in a system where hierarchy is represented by a partially ordered set was introduced by Akl et al. But the key generation algorithm of Akl et al. is infeasible when there is a large number of users. To overcome this shortage, in 1985, MacKinnon et al. proposed a paper containing a condition which prevents cooperative attacks and optimizes the assignment. In 2005, Kim et al. proposed the key management systems for using one-way hash function, RSA algorithm, poset dimension and Clifford semigroup in the context of modern cryptography, the key management system using Clifford semigroup of imaginary quadratic non-maximal orders. We, in this paper, show that Kim et al. cryptosystem is insecure in some reasons and propose a revised cryptosystem.

• Journal of the Korean Institute of Landscape Architecture
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• v.23 no.1
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• pp.95-109
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• 1995

All human spatial behavior and psychological stress are affected by the 'Privacy'of each space. This Paper deals with the theoretical review of 'privacy'concept and establishment of 'Privacy Model' that can be a useful design tool. 'Privacy Index(Pl)' model of 10 point scale, which is based on 'Hierarchic system of Privacy' in urban spaces by Chermeyeff and Alexander(1963), was established as a hypothetical model in this study. And'Activity Suitability', based on each hierarchy of primacy level, was investigated at each site to construct the validity of 'Privacy Model'. Total 67 sites were investigated by on.-site questionnaire in 3 types of outdoor spaces, (Park), (Campus), and (Garden) respectively. The major results are as follows; 1. The P7rivacy level of earth spaces, distributed from to in and . and (Groun Private> spaces are dominant In , spaces are dondnant 2, Privacy level, based on , showed higher privacy level than that of . This means the criteria of each privacy level should be modified for more specific space. The . could be derived from the (Activity Suitability) of each space. 3.The cognition of privacy level. by user group, showed no significant difference in dach group by sex, age, education, and job, respectively.

• Journal of Gynecologic Oncology
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• v.29 no.6
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• pp.98.1-98.13
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• 2018

Objective: We describe a systematic review and meta-analysis of the performance of ${18}F$-fluorodeoxyglucose ($^{18}F-FDG$) positron emission tomography/computed tomography (PET/CT) for detecting metastasis in ovarian cancer. Methods: MEDLINE and Embase were searched for diagnostic accuracy studies that used $^{18}F-FDG$ PET or PET/CT for pre-treatment staging, using surgical findings as the reference standard. Sensitivities and specificities were pooled and plotted in a hierarchic summary receiver operating characteristic plot. Potential causes of heterogeneity were explored through sensitivity analyses. Results: Eight studies with 594 patients were included. The overall pooled sensitivity and specificity for metastasis were 0.72 (95% confidence interval [CI]=0.61-0.81) and 0.93 (95% CI=0.85-0.97), respectively. There was considerable heterogeneity in sensitivity ($I^2=97.57%$) and specificity ($I^2=96.74%$). In sensitivity analyses, studies that used laparotomy as the reference standard showed significantly higher sensitivity and specificity (0.77; 95% CI=0.67-0.87 and 0.96; 95% CI=0.92-0.99, respectively) than those including diagnostic laparoscopy (0.62; 95% CI=0.46-0.77 and 0.84; 95% CI=0.69-0.99, respectively). Higher specificity was shown in studies that confirmed surgical findings by pathologic evaluation (0.95; 95% CI=0.90-0.99) than in a study without pathologic confirmation (0.69; 95% CI=0.24-1.00). Studies with a lower prevalence of the FDG-avid subtype showed higher specificity (0.97; 95% CI=0.94-1.00) than those with a greater prevalence (0.89; 95% CI=0.80-0.97). Conclusion: Pre-treatment $^{18}F-FDG$ PET/CT shows moderate sensitivity and high specificity for detecting metastasis in ovarian cancer. With its low false-positive rate, it can help select surgical approaches or alternative treatment options.

• Korean Journal of Environment and Ecology
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• v.29 no.3
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• pp.454-461
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• 2015

This study aims to classify the biotope types based on the vegetation community in built-up areas by different land use and to map the plant communities. By classifying biotopes according to a taxonomic system, the characteristics of a biological community can be well-represented. The biotope classification indexes for the target area include human behavioral factors such as land use intensity, land-use patterns and land-cover types. The type classification was divided into four hierarchic ranks starting with Biotope Class, next by Biotope Group and Biotope Type and lastly by Biotope Sub-Type. The Biotope Class was first divided into two areas: the areas improved by humans and the areas unimproved by humans. The improved areas were again divided into permeable and non-permeable regions on the Biotope Group level. In the Biotope Type level, permeable paving areas were divided into areas with wide gap pavers and those with narrow gap pavers. The differential species of each biotope type are Lindera glauca, Conyza canadensis, Mazus pumilus, Vicia tetrasperma, Crepidiastrum sonchifolium, Zoysis japonica, Potentilla supina and Festuca arundinacea. The results of this study suggest that the biotope classification methodology, using a subjective phytosociological approach, is a useful and valuable tool and the results also suggest the possibility of applying more objective and scientific methods in mapping and classifying various environments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.2156-2169
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• 2012

This study was performed to find out the relationship between farmer's syndrome and self-conscious fatigue symptoms in farmers of suburban area. The questionnaire was prepared to survey the socio-demographic characteristics, health-related behaviors, farming activities, farmer's syndrome, and self-conscious fatigue symptoms of the farmers, and the survey was carried out from April 1 to June 30, 2011 by interviewing 296 farmers residing suburban area of Daejeon city. As a results, the ratio of farmers who had positive farmer's syndrome, doubtful syndrome, and no syndrome were 34.1%, 47.6%, and 18.2%, respectively. The farmer's syndrome was positively correlated with the self-conscious fatigue symptoms, and farmers with self-conscious fatigue symptoms in high risk group were at higher risk of having farmer's syndrome. The results of hierarchic multiple regression analysis indicated that sex, education, health, and self-conscious fatigue symptom were correlated with the farmer's syndrome. Among the affective factors variables, independently self-conscious fatigue symptom was the most influential. As a conclusion, the occurrence of farmer's syndrome was influenced by the socio-demographic characteristics, health-related behaviors, and self-conscious fatigue symptoms of the farmers. Especially, self-conscious fatigue symptom was independently influenced the occurrence of farmer's syndrome.