• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.281-282
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• 2023

본 논문에서는 안드로이드 앱 기반의 스마트폰에 내장된 GPS센서와 IoT 기반의 사고 감지 시스템을 융합하여 실시간 교통사고를 알려주는 자동화 시스템을 설계하고 구현한다. GPS 센서를 통해 사용자의 위치를 감지하고 사고 현장의 GPS와 정보를 무선 네트워크와 MQTT기반의 프로토콜로 전달받아 실시간으로 사고 현장을 알려주는 역할을 한다. 소방관이나 경찰관같은 업무 처리자의 경우 직접적인 신고가 아닌 자동화로 업무의 환경을 개선해 골든 타임을 확보를 용이하게 한다.

• Imaging Science in Dentistry
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• v.34 no.1
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• pp.31-34
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• 2004

Purpose: To compare the size of the masseter and lateral pterygoid muscle between the affected and the unaffected side of the patients who have the chief complaints of the mandibular asymmetry. Materials and Methods: Twenty two patients (male: 4, female: 18, average age: 21.3 year-old) were radiographed using posterior-anterior (P-A) cephalography and computed tomography (CT). On P-A cephalography, the degree of deviation was determined by the distance from the mentum to the vertical reference line through the crista galli and the anterior nasal spine. On the scanned tracing papers of the maximum cross-sectional area of the masseter and lateral pterygoid muscle using axial CT images, the pixel number was measured. The ratio of the affected : unaffected sides were obtained. For the masseter and lateral pterygoid muscle, the relationship between the muscular volume and degree of skeletal hypoplasia was studied. Results : The half cases showed no skeletal asymmetry. The lateral pterygoid muscle of the affected side was larger significantly than unaffected side (p<0.05). However, there was no significant difference between two sides in the cases of skeletal asymmetry. There was only significant difference in the cases without skeletal asymmetry (p<0.05). Conclusions : To some extent, the slight mandibular hypoplasia could affect the growth of some masticatory muscles.

• Imaging Science in Dentistry
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• v.36 no.1
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• pp.63-68
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• 2006

Desmoplastic ameloblastoma is a rare histologic variant of ameloblastoma. It shows important differences in anatomic distribution, histologic appearance, and radiographic findings compared with the general type of ameloblastoma. It is histologically characterized by an abundance of densely collagenous stroma and radiographically a mixed radiolucent-radiopaque lesion. We present three cases of desmoplastic ameloblastoma. All the patients complained on buccal swelling with or without pain and the sites of occurrence were the anterior and the premolar region. Plain radiographs showed mixed radiopaque-radiolucent lesion with ill-defined or diffuse sclerotic margin and no external root resorption. Additionally, CT scans revealetl buccal expansion and relatively well-defined margin of the lesions. The clinical and radiographic features of the presented cases were compared with those of the desmoplastic ameloblastoma in the previous literatures.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11C
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• pp.702-711
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• 2011

In this paper, we derived a closed-form equation of a Best Linear Unbiased Estimator (BLUE) and its Crammer-Rao Lower Bound (CRLB) for the estimation of the position of the emitter based on the Time Difference of Arrival (TDOA) teclmique. The BLUE and CRLB were derived for the case of estimating 2 dimensional position of the emitter with 3 base stations or sensors, and for this purpose, we nsed an approximated equation of the TDOA hyperbola equation obtained from the first order Taylor-series after setting the reference points of the position. The derived equation can be used for any kind of noises which are uncorrelated in each other in the TOA measurement noises and for a white Gaussian noise also.

• Journal of Environmental Health Sciences
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• v.42 no.5
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• pp.333-344
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• 2016

Objectives: This study aimed to examine risk-accepting personality traits and associated factors among farmers. Methods: Data were collected from farmers aged over 40 living in Goryeong, North Gyeongsang-do Province, Korea. Study participants were enrolled in the Korean Rural Cohort study from 2011 to 2014. Surveys for the risk perception of farming were made through face-to-face interviews. Chi-square tests and logistic regression analysis were conducted adjusting for gender, age, marital status, and education. Results: Several factors such as gender, age, marital status, age first worked as a farmer, duration of farming, and history of pesticide poisoning were associated with risk-accepting personality traits among farmers. Farmers with risk-accepting personalities tend to be older, less educated, and have self-employed health insurance. Farmers who started farming after the age of 50 are likely to be risk averse compared to farmers who started farming before the age of 20 (OR=0.41, 95% CI; 0.21, 0.82). Frequent spraying of pesticides was marginally associated with higher risk acceptance among female farmers (OR=1.61, 95% CI: 0.99, 2.64). Male farmers who had experienced pesticide poisoning in their lifetime showed higher odds of risk-accepting personality traits (OR=2.20, 95% CI: 1.03, 4.72) Conclusion: Risk-acceptors were more likely to spray pesticides frequently and to experience more pesticide poisoning compared to risk-averse individuals. This result suggests that farming hazards are to some degree driven by risk-accepting personality traits. Further investigation of how risk-accepting behaviors influence farming practices and pesticide poisoning is needed.

• Journal of Preventive Medicine and Public Health
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• v.32 no.3
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• pp.347-354
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• 1999

Objective: This paper examines the possible toxicity to immune system in farmers chronically exposed to pesticides. Methods : We compared 43 male farmers exposed to pesticides with 29 male residents who had neither past nor current pesticides exposure. The selected variables for studying immunotoxicity were WBC, CD3, CD4, CD8, CD19, CD56, IgG, IgA, IgM, and IL-2. As part of the baseline questionnaires for the immunotoxicity, subjects were asked about kinds of farming, posticides exposure and medical history. Results : None of the variables for studying immunotoxicity showed statistically significant difference between the two groups. Although the results were not statistically significant, CD4 and the CD4/CD8 ratio decreased and CD8 increased. These effects showed a dose response change with exposure level. In the exposed group, the values of CD3, CD4, CD4/CD8 and CD19 decreased and those of the CD8 and CD56 increased compared to the non-exposed group. Also there was higher prevalence of self-reported disease in the exposed group compared to the non-exposed group. Conclusions: Although statistically significant differences in indices of immunotoxicity in farmers exposed to pesticides were not shown, the results suggest that pesticides may decrease immune function. More advanced test methods for immunotoxicity need to be developed and tested in larger population to detect immunotoxic effects of pesticides.

• Imaging Science in Dentistry
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• v.35 no.3
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• pp.167-173
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• 2005

Purpose : To investigate the relationship between three-dimensional (3D) bone imaging parameters and trabecular strength in the mandible. Materials and Methods : Bone specimens were obtained from the mandibles of five male pigs weighing around 110 kg each. Of those, 43 samples were selected for 3D analysis and measured by micro-computed tomography. The five morphometric parameters were trabecular thickness (Tb.Th), bone specific surface (BS/BV), percent bone volume (BV/TV), structure model index (SMI) and degree of anisotropy (DA). Through destructive mechanical testing, strength parameters were obtained. Results : BV/TV, SMI, BS/BV, and Tb.Th showed significant correlations with strength parameters. DA did not show any correlation with the other parameters. In multiple linear regression analysis, BV/TV alone explained $43\%$ of the variance in Young's modulus. By stepwise inclusion of SMI, the variance in the Young's modulus was better explained up to $52\%$. Conclusions : Predicting trabecular strength in the mandible through architectural analysis would be possible. Further study is needed to establish the tendency and variety of trabecular architecture and strength according to the locations within the mandible.

• Journal of Periodontal and Implant Science
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• v.38 no.4
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• pp.589-594
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• 2008

Purpose: Osseointegration of implants in patients with pneumatized maxillary sinuses is difficult to achieve due to the deficiency of available bone in the posterior maxilla after loss of teeth. Maxillary sinus elevation is a method to overcome this problem. In this study, we evaluated the implant survival rate and the relationship between implant survival in patients with sinus elevation by the lateral approach. Materials and Methods: A total of 48 patients were consecutively treated with sinus elevation by the lateral approach between February 2003 & August 2006 at the dental hospital of Chonbuk National university. A total of 113 implants were placed. The mean healing period was 7.1 months and implants were placed after a mean period of 5.6 months. The mean observation period was 21.8 months. Results: Out of the 113 implants placed, fifteen failed, resulting in a survival rate of 86.7%, 18 cases of sinus membrane perforation were observed out of 65 sinuses treated. 33 implants were placed in a perforated site and 10 failed, representing a 60.7% implant survival. 80 implants were placed in a nonperforated site and 5 failed, representing a 92.6% implant survival. Conclusions: Implant placement with sinus elevation is an acceptable treatment for short term results. Sinus membrane perforation and postoperative complications, however, may have an effect on implant failure.

• Korean Journal of Social Welfare
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• v.64 no.2
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• pp.185-212
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• 2012

This study examines changes in income inequality and income mobility associated with a transition to old age. In understanding the dynamics of income distribution over the later life course, it is important to explore the changes in income dispersion and the changes in relative income positions jointly. Data come from Korean Labor and Income Panel Study(KLIPS) 2nd, 7th, 12th wave. The results are as follows. First, a transition to old age is associated with an increase in income inequality. The Gini index of inequality increased steadily over the life course. Second, a transition to old age is associated with substantial income mobility. The Spearman's rank correlation coefficient between two periods was the lowest at the time of the transition. Increasing income dispersion and significant income mobility can be conceptualized as "income insecurity", since the older population are less likely to cope with income fluctuations. Third, in explaining such changes over time, changes in work life during old age and a subsequent decrease in earnings seem to be the most influential factor.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.1
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• pp.1-9
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• 2011

The objective of this paper is to improve the accuracy of the 3D geopositioning extracted from Rational Polynomial Coefficient(RPC) provide in the KOMPSAT-2 metadata files. In this paper, we developed the algorithm to adjust a RFM(Rational Functional Model), and could improve the accuracy of a RFM with this algorithm. Furthermore, when a RFM was adjusted with this algorithm, the effects of the number of GCPs on the accuracy of the adjusted RFM was tested. For accuracy assessment using adjusted RFM, 9 ground control points(GCPs) and 24 check points could be used. Results indicated that the root mean squared errors(RMSEs) of horizontal residual errors calculated 24 check points were 2.20(m). The achieved accuracy of three dimensional object-point determination was 1.72(m) in the X-dimension and 1.37(m) in the Y-dimension and 2.20(m) in the Z-dimension.