• Journal of the Korean Data and Information Science Society
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• v.6 no.1
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• pp.97-103
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• 1995

In this paper, we propose estimators of Gini index of the exponential distribution. We also obtain the distribution and the moments of the proposed estimators. The moments of the proposed estimators are derived by special function. We compare the maximum likelihood estimator (MLE) of Gini index with the proposed estimator of Gini index in the sense of MSE through Monte Carlo Method.

• Journal of Korean society of Dental Hygiene
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• v.13 no.1
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• pp.13-20
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• 2013

Objectives : This research is performed to arrange oral health improvement program and improve the quality of life by raising total health index of male workers. The relationship between the oral health, oral health index and total health index of workers are investigated through the direct or indirect effects based on structural equational modeling. Methods : Total 272 people who work in Gyeong-Nam province participated in this survey. Results : Oral health knowledge has an meaningful direct effects on the oral health practice with ${\gamma}$=.259 and dietary pattern with ${\gamma}$=.224. Total health index has indirect relationship with the oral health index with ${\beta}$=.141 and dietary pattern has direct relationship with the oral health index with ${\beta}$=.315. The oral health index has direct relationship with total health index with ${\beta}$=.454. Conclusions : Our research shows that there is meaningful relationship between the oral health, oral health index and total health index of workers. The systematic and continuous programs for oral health should be transferred to workers for the raise of oral health and the quality of the life.

• Journal of Periodontal and Implant Science
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• v.38 no.4
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• pp.699-708
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• 2008

Purpose: The aim of this study was to investigate the effect of tongue cleaner-equipped manual toothbrush on tooth cleanness, tongue cleanness and malodor index. Materials and methods: 504 subjects were included in this study. At 1st visit, basic information such as age, sex, smoking amount and alcohol consumption was recorded. Self assessment by individual subjects was performed regarding satisfaction to old toothbrush and toothbrushing habit. Tooth cleanness, tongue cleanness and malodor index was assessed by professional researcher. Tongue cleaner-equipped manual toothbrush was given to each subject with proper toothbrushing instruction. After 1 month passed, self assessment and researcher assessment regarding the same index were performed and analyzed statistically by chi-square test. Results: At 1st visit subjects seem to ignore tongue cleansing and showed poor tooth cleanness index, tongue cleanness index and malodor index, however the same subjects were motivated to clean their tongue and teeth and presented statistically improved distribution pattern in tooth cleanness index, tongue cleanness index and malodor index after using tongue cleaner-equipped manual toothbrush(p<0.01). Satisfaction to tongue cleaner-equipped manual toothbrush was 98%. Conclusion: Tongue cleaner-equipped manual toothbrush would be an effective tool for maintaining good oral hygiene through improving tooth and tongue cleanness and preventing malodor formation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.8
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• pp.2913-2929
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• 2014

Traditional vector quantization (VQ) schemes encode image blocks as VQ indices, in which there is significant similarity between the image block and the codeword of the VQ index. Thus, the method can compress an image and maintain good image quality. This paper proposes a novel lossless VQ indices compression algorithm to further compress the VQ index table. Our scheme exploits the high correlation of adjacent image blocks to search for the same VQ index with the current encoding index from the neighboring indices. To increase compression efficiency, codewords in the codebook are sorted according to the degree of similarity of adjacent VQ indices to generate a state codebook to find the same index with the current encoding index. Note that the repetition indices both on the search path and in the state codebooks are excluded to increase the possibility for matching the current encoding index. Experimental results illustrated the superiority of our scheme over other compression schemes in the index domain.

• Journal of Korean Society for Quality Management
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• v.40 no.3
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• pp.234-244
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• 2012

Purpose: In the private sector, many Customer Satisfaction Index Models have already been developed and are being applied in a variety of industries. In spite of continuously increasing of quality for military goods, measuring tools of Quality Satisfaction have not been developed yet. Method: In 2004, Defense Quality Assurance Agency and Seoul National University jointly developed MCSI(Military Customer Satisfaction Index) as a benchmark NCSI(National Customer Satisfaction Index), but it is limited to aply to military goods. We focused on product quality and developed MQSI(Military Quality Satisfaction Index) Model. Result: We propose a new Satisfaction Index Model(MQSI, Military Quality Satisfaction Index) that can be applied to military goods. Conclusion: In this study, configuration and variables of MQSI Model are described. Also the result of preliminary survey is briefly explained.

• Korean Journal of Ecology and Environment
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• v.44 no.2
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• pp.155-171
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• 2011

The research assessed water quality using physico-chemical factors, trophic status index and attached diatom index in 10 reservoirs located in Chungcheongnam-do from October 2007 to June 2008. The physico-chemical water quality assessments revealed that Dangjin-gun (St. 1~5), which displayed a high chemical oxygen demand (V and VI) and chlorophyll-${\alpha}$ (Eutrophic-Hypereutrophic), was more polluted than Yesan and Cheongyang-gun. The sample were also hypereutrophic [trophic status index (TSI) 74.6] and ${\beta}$-mesosaprobic [diatom assemblage index to the organic water pollution (DAIpo) 44.47]. Yesan and Cheongyang-gun. Which were mid-level in their pollution status, were eutrophic (TSI 56.9) and ${\alpha}$-oligosaprobic (DAIpo 60.11). TSI correlated strongly with the attached diatom index (of DAIpo 0.60~0.62, and trophic diatom index of 0.72~0.74). Hence, the attached diatom index can be used with the trophic status assessment of lakes using TSI, and lake trophic status index (LTSI).

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.5
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• pp.328-334
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• 2020

Objectives: This study aimed to validate the effectiveness of a recently proposed difficulty index for removal of impacted mandibular third molars based on extraction time and suggest a modified difficulty index including the presence of pathologic conditions associated with third molars. Materials and Methods: This retrospective study enrolled 65 male patients younger than 25 years with third molars. Extraction time was calculated from start of the incision to the last suture. The difficulty scores for third molars were based on spatial relationship (1-5 points), depth (1-4 points), and ramus relationship (1-3 points) using cone-beam computed tomography. The difficulty index was defined as follows: I (3-4 points), II (5-7 points), III (8-10 points), and IV (11-12 points). The modified difficulty score was calculated by adding one point to the difficulty score if the third molar was associated with a pathologic condition. Two modified difficulty indices, based on the presence of pathologic conditions, were as follows: the half-level up difficulty index (HDI) and the one-level up difficulty index (ODI) from the recently proposed difficulty index. Results: The correlations between extraction time and difficulty index and or modified difficulty indices were significant (P<0.001). The correlation coefficient between extraction time and difficulty index was 0.584. The correlation coefficients between extraction time and HDI and ODI were 0.728 and 0.764, respectively. Conclusion: Extraction time of impacted third molars exhibited a moderate correlation with difficulty index and was strongly correlated with the modified indices. Considering the clinical implications, the difficulty index of surgical extraction should take into consideration the pathologic conditions associated with third molars.

• Journal of the Korean Mathematical Society
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• v.42 no.5
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• pp.1003-1015
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• 2005

Klein proved that polynomial rings over nil rings of bounded index are also nil of bounded index; while Puczylowski and Smoktunowicz described the nilradical of a power series ring with an indeterminate. We extend these results to those with any set of commuting indeterminates. We also study prime radicals of power series rings over some class of rings containing the case of bounded index, finding some examples which elaborate our arguments; and we prove that R is a PI ring of bounded index then the power series ring R[[X]], with X any set of indeterminates over R, is also a PI ring of bounded index, obtaining the Klein's result for polynomial rings as a corollary.

• Journal of the Korean Mathematical Society
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• v.52 no.6
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• pp.1305-1321
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• 2015

We dene new link invariants which are called the quasitoric braid index and the cyclic length of a link and show that the quasitoric braid index of link with k components is the product of k and the cycle length of link. Also, we give bounds of Gordian distance between the (p,q)-torus knot and the closure of a braid of two specific quasitoric braids which are called an alternating quasitoric braid and a blockwise alternating quasitoric braid. We give a method of modication which makes a quasitoric presentation from its braid presentation for a knot with braid index 3. By using a quasitoric presentation of $10_{139}$ and $10_{124}$, we can prove that $u(10_{139})=4$ and $d^{\times}(10_{124},K(3,13))=8$.

• International Journal of Contents
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• v.1 no.1
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• pp.50-58
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• 2005

Generally, multidimensional data such as image and spatial data require large amount of storage space. There is a limit to store and manage those large amounts of data in single workstation. If we manage the data on parallel computing environment which is being actively researched these days, we can get highly improved performance. In this paper, we propose a parallel multidimensional index structure that exploits the parallelism of the parallel computing environment. The proposed index structure is nP(processor)-nxmD(disk) architecture which is the hybrid type of nP-nD and 1P-nD. Its node structure in-creases fan-out and reduces the height of an index. Also, a range search algorithm that maximizes I/O parallelism is devised, and it is applied to k-nearest neighbor queries. Through various experiments, it is shown that the proposed method outperforms other parallel index structures.