• Journal of the Korea Society of Computer and Information
• /
• v.17 no.3
• /
• pp.1-10
• /
• 2012

A low-complexity Multiplication over GF(2m) and multiplier circuit has been proposed by using cyclic-shift coefficients and the irreducible trinomial. The proposed circuit has the parallel input/output architecture and shows the lower-complexity than others with the characteristics of the cyclic-shift coefficients and the irreducible trinomial modular computation. The proposed multiplier is composed of $2m^2$ 2-input AND gates and m (m+2) 2-input XOR gates without the memories and switches. And the minimum propagation delay is $T_A+(2+{\lceil}log_2m{\rceil})T_X$. The Proposed circuit architecture is well suited to VLSI implementation because it is simple, regular and modular.

• The Korean Journal of Applied Statistics
• /
• v.26 no.1
• /
• pp.15-22
• /
• 2013

In clinical study or epidemic research, the $2{\times}2$ frequency table is useful to present a summary statistic The values of four cells in $2{\times}2$ table use to calculate the effect measures such as risk ratio, relative ris ratio or odds ratio. In this paper, we suggest that the improved visualization method using a radar diagram supported by MS-office Excel from the $2{\times}2$ frequency table is able to understand and draw easily betweendiagnosti measures such as sensitivity, specificity, predictivity, and likelihood ratio. We use some numerical example in order to show the usage of the proposed method.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.8 no.2
• /
• pp.70-81
• /
• 1998

This paper proposes an accurate and cost-effective COA defuzzifier of fuzzy logic controller (FLC). The accuracy of the proposed COA defuzzifier is obtained by involving both membership values and spans of membership functions in calculating a crisp value. The cost-effectiveness of the proposed COA defuzzifier is obtained by replacing the division in the COA defuzzifier by finding an equilibrium point of both the left and right moments. The proposed COA defuzzifier has two disadvantages that it ncreases the hardware complexity due to the additional multipliers and it takes a lot of computation time to find the moment equilibrium point. The first disadvantage is overcome by replacing the multipliers with the stochastic AND operations. The second disadvantage is alleviated by using a coarse-to-fine searching algorithm that accelerates the finding of moment equilibrium point. Application of the proposed COA defuzzifier to the truck backer-upper control problem is performed in the VHDL simulation and the control accuracy of the proposed COA defuzzifier is compared with that of the conventional COA defuzzifier in terms of average tracing distance.

• 한국디지털정책학회:학술대회논문집
• /
• 2006.12a
• /
• pp.327-336
• /
• 2006

The odds ratio is used for assessing the disease-exposure association, because epidemiological data for case-control of cohort studies are often summarized into 2 ${\times}$ 2 tables. In this paper we define the odds ratio function(ORF) that extends odds ratio used on discrete survival event data to continuous survival time data and propose estimation procedures with censored data. The first one is a nonparametric estimator based on the Nelson-Aalen estimator of comulative hazard function, and the others are obtained using the concept of empirical odds ratio. Asymptotic properties such as consistency and weak convergence results are also provided. The ORF provides a simple interpretation and is comparable to survival function or comulative hazard function in comparing two groups. The mean square errors are investigated via Monte Carlo simulation. The result are finally illustrated using the Melanoma data.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.9
• /
• pp.1538-1544
• /
• 2006

This paper proposes a non-systolic parallel $AB^2+C$ Computing unit based on irreducible AOP order m of $GF(2^m)$. Proposed circuit have only AND gates and EX-OR gates, composes of cyclic shift operation, multiplication operation power operation power-sum operation and addition operation using a merry irreducible AOP. Suggested operating a method have an advantage high speed data processing, low power and integration because of only needs AND gates and EX-OR gates. $AB^2+C$ computing unit has delay-time of $T_A+(1+[log^m_2])T_X$.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.37 no.1
• /
• pp.91-96
• /
• 2010

Many studies have shown that there is a strong relationship between the congenitally missing primary teeth and their succedaneous permanent teeth. However, especially in case of lower anterior region, we can observe the existence of permanent teeth even though their precedent primary teeth were missed at times. The purpose of this study was to reveal the relationship between the congenitally missing primary lower anterior teeth and their succedaneous permanent teeth in Korean children. Total of 14,307 children, under 6 years of age, who attended the department of pediatric dentistry, Seoul National University Dental Hospital, Seoul, Korea from January 1st 2005 to September 5th 2008 were radiologically examined using the panoramic x-ray in order to analyze the relationship between the congenitally missing primary lower anterior teeth and their succedaneous permanent teeth. The results were as follows : 1. The prevalence of congenitally missing lower anterior teeth in primary dentition was 0.24%. The odds ratio of both the primary and permanent anterior teeth being present was 7163.5 and only the permanent anterior teeth being present was 0.79. 2. The percentage of all succedaneous permanent teeth being present was 44.12% in cases of missing lower primary anteriors. The odds ratio of at least one succedaneous permanent teeth being present in cases of bilateral primary anterior teeth missing was 1.57 times more common than in cases of unilateral primary teeth missing. 3. The odds ratio of primary missing teeth being unilateral was 2.2 times higher in females. Moreover, the odds ratio of succedaneous permanent teeth being present in cases of primary teeth missing was 2.22 times higher in males.

• Journal of radiological science and technology
• /
• v.45 no.4
• /
• pp.355-363
• /
• 2022

This study was to investigate the prevalence rate of musculoskeletal disorders in relation to general characteristic factors, living environment factors, and work environment factors for sonographer's. For the response questions, the guidelines for musculoskeletal burden work were used. For statistical analysis, SPSS 26.0 version was used. For the common body parts of the sonographer's who responded, the prevalence was investigated by dividing the group into a group with high pain or discomfort and a group with low pain or discomfort according to the degree to which they experienced symptoms during the past 12 months. Multiple logistic regression analysis was used to determine the variance inflation factor(VIF), odds ratio (OR) and corresponding 95% confidence interval (CI). A p-value of <0.05 was considered statistically significant. As a result, housework hours, examination history, regular physical activity, number of patient examinations per day, and sitting posture were investigated as variables for rate musculoskeletal disorders. The sonographer's occupational group was found to have a high prevalence rate of musculoskeletal disorders like various other occupational groups. Based on the results of this study, it is judged that musculoskeletal disorders can be reduced by recognizing musculoskeletal disorders and improving work environment factors.

• The Journal of Korean Orthopaedic Ultrasound Society
• /
• v.7 no.2
• /
• pp.77-83
• /
• 2014

Purpose: The purpose of current study was to evaluate the validity of the existing radiological classifications as a diagnostic modality for predicting characteristics of calcific deposition in calcific tendinitis of the shoulder joint. For that purpose, we determined the inter-observer reliability for evaluating diagnostic precisions of the classification and also evaluated diagnostic accuracy of predicting the toothpaste type calcific deposition. Materials and Methods: We performed retrospective study with total 26 patients surgically treated with calcific tendinitis of the shoulder joint from March 2010 to October 2013. Two independent observers reviewed preoperative radiographs of shoulder joints, and classified the characteristics of calcific depositions according to the criteria of Gartner, DePalma and Patte. Cohen's kappa were calculated for each classifications to evaluate inter-observer reliability. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio were determined for type of calcific depositions with Gartner type III, DePalma type I, and Patte type II for predicting toothpaste type calcific deposition. Results: The values of Cohen's kappa were the highest in the classification of Patte, 0.62, and the values for the classifications of DePalma and Gartner were 0.56 and 0.36, respectively. The sensitivities for predicting toothpaste type calcific deposition in Gartner Type III, DePalma type I and Patte type II were 83.3%, 91.7%, and 58.3%, respectively. Specificities were 85.7% 50.0% and 64%, positive likelihood ratios were 5.833, 1.833 and 1.633, negative likelihood ratios were 0.194, 0.167 and 0.648, and diagnostic odds ratios were 30.00, 11.00 and 2.52, respectively. Conclusion: There were no radiologic classifications of calcific tendinitis which has both high precision and accuracy. Further studies with other diagnostic modalities such as ultrasonography are needed for predicting characteristics of calcific deposition in calcific tendinitis of the shoulder joint.

• Digital Contents
• /
• no.10 s.137
• /
• pp.92-95
• /
• 2004

모바일게임에 대한 장밋빛 미래를 이야기하던 게 불과 몇 개월 전 일이었다. 잘 만든 모바일게임 하나로 몇 억원 정도의 수익을 거둬들이고,해외 수출에 있어서도 국내 기술이 충분히 승산 있게 판매되며, 모바일 전문 게임업체로 코스닥 등록을 추진하는 업체까지 생겼다. 모바일게 임은 관련 분야 종사업체들의 희망이기도 했다. 개발 기간이 다른 소프트웨어에 비해 길지 않으며, 약간의 기간은 있지만 현금결제가 매월 깔끔하게 정산되고, 생산라인만 요령껏 갖추면 양산 모델로까지 운영이 가능한 괜찮은 사업모델이었다. 변덕이 심해서일까? 요즘 언론에서는 입장을 바꿔서 모바일게임 콘텐츠 위기론을 이야기하곤 한다. 몇몇 대표적인 업체를 제외하고는, 심지어는 그러한 업체에 속하는 업체들 조차도 모바일게임 시장이 쉽지만은 않다고 한다(먹고살기 어렵다 내지 힘들어 죽겠다는 표현이 오히려 정확하긴 하다).

• Journal of the Korean Data and Information Science Society
• /
• v.25 no.2
• /
• pp.403-410
• /
• 2014

Binary logistic regression analysis is a statistical technique that explains binary response variable by quantitative or qualitative explanatory variables. In the binary logistic regression model, the probability that the response variable equals, say 1, one of the binary values is to be explained as a transformation of linear combination of explanatory variables. This is one of big barriers that non-statisticians have to overcome in order to understand the model. In this study, an educational tool is developed that explains the need of the binary logistic regression analysis using Excel VBA. More precisely, this tool explains the problems related to modeling the probability of the response variable equal to 1 as a linear combination of explanatory variables and then shows how these problems can be solved through some transformations of the linear combination.