• The KIPS Transactions:PartD
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• v.9D no.5
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• pp.745-754
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• 2002

The Google search site (http://www.google.com), which was introduced in 1998, implemented the PageRank algorithm for the first time. PageRank is a ranking method based on the link structure of the Web pages. Even though PageRank has been implemented and being used in various commercial search engines, implementation details did not get documented well, primarily due to business reasons. Implementation techniques introduced in [4,8] are not sufficient to produce PageRank values of Web pages. This paper explains the techniques[4,8], and suggests major data structure and four implementation techniques in order to apply the PageRank algorithm. The paper helps understand the methods of applying PageRank algorithm by means of showing a real system that produces PageRank values of Web pages.

• The Korean Journal of Applied Statistics
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• v.37 no.2
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• pp.239-253
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• 2024

This research applies both point-wise and pair-wise learning strategies within the learning-to-rank (LTR) framework to predict horse race rankings in Seoul. Specifically, for point-wise learning, we employ a linear model and random forest. In contrast, for pair-wise learning, we utilize tools such as RankNet, and LambdaMART (XGBoost Ranker, LightGBM Ranker, and CatBoost Ranker). Furthermore, to enhance predictions, race records are standardized based on race distance, and we integrate various datasets, including race information, jockey information, horse training records, and trainer information. Our results empirically demonstrate that pair-wise learning approaches that can reflect the order information between items generally outperform point-wise learning approaches. Notably, CatBoost Ranker is the top performer. Through Shapley value analysis, we identified that the important variables for CatBoost Ranker include the performance of a horse, its previous race records, the count of its starting trainings, the total number of starting trainings, and the instances of disease diagnoses for the horse.

• Journal of Korean Home Economics Education Association
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• v.7 no.2
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• pp.1-18
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• 1995

The purpose of this study was to investigate the teachers’attitudes toward the middle and high school student uniform. The questionnaire included independent variables about teacher themselves and school surroundings, and questions about teachers’attitudes toward school uniform. The participants were 316 middle and high school teachers in Chonbuk province. Means, standard deviations, frequencies, and percentages were calculated. ANOVA test was used for differences and scheffe-test was followed. The results were: 1. Teachers were content with “Students in uniform are upright and look more studentlkie.”“It’s easy to supervise students outdoors.”, and “There’s few efficiencies in coping with the temperature alternating.”, “Students in uniform hardly can reveal their originality.”and “It’s inconvenient for the students to be dynamic in uniform.” 2. Teachers in high schools and in private schools showed more positive attitudes toward uniform. And the male teachers, teachers graduated from general college, married teachers, and teachers who have a career of more than 20 years showed more positive attitudes toward uniform. More variables concerned about teacher themselves showed more significant differences than those about school surroundings. 3. Most of teachers showed positive attitudes toward uniform. The rank order of the reasons for the teacher’s positive attitudes were “Students in uniform are upright and look more studentlike.”, “It’s easy to supervise students outdoors.”, and “There’s no noticible distinction between the rich and the poor students.”The rank order of the reason for the teachers’negative at titudes were “Student in uniform could hardly reveal their originality.”, “It’s inconvenient for the student to be dynamic in uniform.”, and ”As they have to get the street clothes besides, economic burden becomes double in reality.”4. More than half of the teachers who are working at schools with uniform showed positive attitudes toward uniform. The rank order of reasons for the teachers’positive attitudes were “Students in uniform are upright and look more studentlike.”,“It’s easy to supervise students outdoors.”and “Economic burden could be decreased.”“The rank order of the reasons for the negative attitudes were “It’s inconvenient for the student to be dynamic in uniform.”, “Students in uniform could hardly reveal their originality.”, and “Students cannot feel free in mind with uniform.”5. Teachers overall showed positive attitudes toward uniform whether they work ar schools with uniform or without it.

• Journal of applied mathematics & informatics
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• v.14 no.1_2
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• pp.115-122
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• 2004

We characterize the additive operators preserving rank-additivity on symmetry matrix spaces. Let $S_{n}(F)$ be the space of all $n\;\times\;n$ symmetry matrices over a field F with 2, $3\;\in\;F^{*}$, then T is an additive injective operator preserving rank-additivity on $S_{n}(F)$ if and only if there exists an invertible matrix $U\;\in\;M_n(F)$ and an injective field homomorphism $\phi$ of F to itself such that $T(X)\;=\;cUX{\phi}U^{T},\;\forallX\;=\;(x_{ij)\;\in\;S_n(F)$ where $c\;\in;F^{*},\;X^{\phi}\;=\;(\phi(x_{ij}))$. As applications, we determine the additive operators preserving minus-order on $S_{n}(F)$ over the field F.

• Journal of Environmental Impact Assessment
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• v.6 no.1
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• pp.111-119
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• 1997

This study was carried out to suggest the best statistical test which may be used to quantify the change of water quality between two groups. Traditional t-test may not be used in cases where the normality of underlying population distribution is not assured. Three non-parametric tests which are based on the relative order of the measurements, were studied to find out the applicability in water quality data analysis. The sign test is based on the sign of the deviation of the measurement from the median value, and the binomial distribution table is used. The signed rank test utilizes not only the sign but also the magnitude of the deviation. The Wilcoxon rank-sum test which is basically same as Mann-Whitney test, tests the mean difference between two independent samples which may have missing data. Among the three non-parametric tests studied, the singed rank test was found out to be applicable in the quantification of the change of water quality between two samples.

• Journal of Periodontal and Implant Science
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• v.37 no.4
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• pp.849-857
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• 2007

Purpose: The purposes of this study were to compare and quantify the expressions of RANK and RANKL in the gingival tissues of non-periodontitis patient and patients with chronic periodontitis, in order to understand the contribution of these proteins to periodontal destruction. Material and methods: Gingival tissue samples were obtained during periodontal surgery or tooth extraction. According to the patient's systemic condition & clinical criteria of gingiva, each gingival sample was divided into two groups. Group 1 (n=8) is clinically healthy gingiva without bleeding and no evidence of bone resorption or periodontal pockets, obtained from non-periodontitis patients. Group 2 (n=8) is inflammed gingiva from patients with chronic periodontitis. Tissue samples were prepared and analyzed by Western blotting. The quantification of RANK and RANKL were performed using a densitometer and statistically analyzed by Student's t-Test. Results: The expression of RANK were similar in group 1 and 2. The difference between group 1 and 2 was not statistically significant. And the mean amount of RANKL was more increased in group 2 than group 1. The difference between group 1 and group 2 was statistically significant. Conclusion: The expression level RANK didn't show any significant difference between healthy tissue from non-periodontitis patients and inflamed tissue from chronic periodontitis, but the expression level of RANKL in inflammed tissue from chronic periodontitis showed significantly increased tendency compared to healthy gingiva from non-periodontitis patients. Therefore, characteristics of RANK and RANKL in progress of chronic periodontitis would be basis of further studies in diagnostic method and treatment index of the disease.

• Journal of Information Processing Systems
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• v.9 no.2
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• pp.217-236
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• 2013

Ranking thousands of web documents so that they are matched in response to a user query is really a challenging task. For this purpose, search engines use different ranking mechanisms on apparently related resultant web documents to decide the order in which documents should be displayed. Existing ranking mechanisms decide on the order of a web page based on the amount and popularity of the links pointed to and emerging from it. Sometime search engines result in placing less relevant documents in the top positions in response to a user query. There is a strong need to improve the ranking strategy. In this paper, a novel ranking mechanism is being proposed to rank the web documents that consider both the HTML structure of a page and the contextual senses of keywords that are present within it and its back-links. The approach has been tested on data sets of URLs and on their back-links in relation to different topics. The experimental result shows that the overall search results, in response to user queries, are improved. The ordering of the links that have been obtained is compared with the ordering that has been done by using the page rank score. The results obtained thereafter shows that the proposed mechanism contextually puts more related web pages in the top order, as compared to the page rank score.

• Journal of Korean Academy of Nursing
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• v.7 no.2
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• pp.117-127
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• 1977

Depressive status of the adolescence in 437 normal, 416 orphan, 133 physically handicapped and 109 deaf-mute children were compared with the Self- Rating Depression Scale developed by Zung, from April 26 to July 4, 1976. The subjects were divided into two groups, early adolescence for age of 10 to 14 and ate adolescence of age of 15 to 18. The results were as follows : 1. The depression score was higher in late adolesce co than in early adolescence except deaf - mutes, 2. The depression score was not different significantly between the sexes in all groups. 3. The depression score was significantly higher in the group of orphan, physically handicapped and deaf - mute children then in the normal. 4. The depression score was significantly higher in the orphans than in the physically handicapped children. It showed tendency to be higher in the deaf - mutes than in the physically handicapped children. 5. In comparison with the rank order of the Self - Rating Depression Scale items, normal group was inclined to have psychological symptoms in higher rank order, but orphan and deaf - mute group was inclined to have somatic symptoms in higher rank order.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.12
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• pp.4604-4623
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• 2014

Authentication mechanisms coupled with strong encryption techniques are used for network security purposes; however, given sufficient time, well-equipped intruders are successful for compromising system security. The authentication protocols often fail when they are analysed critically. Formal approaches have emerged to analyse protocol failures. In this study, Communicating Sequential Processes (CSP) which is an abstract language designed especially for the description of communication patterns is employed. Rank functions are also used for verification and analysis which are helpful to establish that some critical information is not available to the intruder. In order to establish this, by assigning a value or rank to each critical information, it is shown that all the critical information that can be generated within the network have a particular characterizing property. This paper presents an application of rank functions approach to an authentication protocol that combines delaying the decryption process with timed authentication while keys are dynamically renewed under pseudo-secure situations. The analysis and verification of authentication properties and results are presented and discussed.

• Journal of Internet Computing and Services
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• v.16 no.3
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• pp.105-116
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• 2015

The Sewol ferry catastrophe that took place on April 16 2014 was unprecedented in terms of its sociopolitical implications, which had reverberated throughout the Korean nation. Mindful of such distinct characteristics of the Sewol ferry catastrophe, this thesis looks into the salience of the agendas portrayed in Twitter and Portal News coverage on the disaster and the correlation between the attribute-specific agendas of the foregoing mediums by making use of the agenda rank order correlation method. Extraction and analysis of big data revealed that first, while the hypothesis that there were little difference in terms of salience among the main agendas between Twitter and Portal News was dismissed, the rank order correlation proved to be high as regards the main agendas on Twitter and Portal News. This signifies that Twitter agendas exert influence over those on Portal News. Next, and regarding the five main agendas on the incident, there existed differences in salience between the attribute-specific agendas of the two mediums, with low figures for corresponding rank order correlations. Such results signify that Twitter and Portal News have little influence over each other as regards their agenda rank order correlation.