• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.4 s.310
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• pp.50-57
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• 2006

In Electronic Commerce, the latest most of the personalized recommender systems have applied to the collaborative filtering technique. This method calculates the weight of similarity among users who have a similar preference degree in order to predict and recommend the item which hits to propensity of users. In this case, we commonly use Pearson Correlation Coefficient. However, this method is feasible to calculate a correlation if only there are the items that two users evaluated a preference degree in common. Accordingly, the accuracy of prediction falls. The weight of similarity can affect not only the case which predicts the item which hits to propensity of users, but also the performance of the personalized recommender system. In this study, we verify the improvement of the prediction accuracy through an experiment after observing the rule of the weight of similarity applying Vector similarity, Entropy, Inverse user frequency, and Default voting of Information Retrieval field. The result shows that the method combining the weight of similarity using the Entropy with Default voting got the most efficient performance.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2009.04a
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• pp.23-28
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• 2009

The purpose of this study was to improve not only wet-end performances but also paper characteristics by the modification of various factors like molecular design and ionic characteristics of polyacrylamides First of all physical characteristics were observed after modify molecular design of the cationic polyacrylamides to linear, branched and cross-linked. In addition it was found analysis method to confirm branch degree of cationic polyacrylamides to combine ionic titration characteristics and spectroscopic behavior, After application of these structure modified polyacrylamides to the multiple retention systems with inorganic microparticles, it was found adjusting of branch degree of polyacrylamides was very important to optimize wet-end improvement. Second, After polymerization of amphoteric polyacrylamide to have both of cationic and anionic functional group in the polymer, we observed not only physical characteristics but also wet-end improvement to apply recycled pulp and found that the improvement of solution stability to prevent hydrolysis and increase of ash retention dramatically to compare traditional cationic polyacrylamide retention aid, Finally, After polymerization of anionic polyacrylamide, we observed not only wet-end improvement but also paper characteristics to apply preflocculation of PCC and it was found the improvements of flocculation efficiency, retention, ash retention, optical properties of the paper and bursting strength to compare traditional preflocculant of cationic polyacrylamide.

• Journal of Korean society of Dental Hygiene
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• v.13 no.2
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• pp.231-237
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• 2013

Objectives : The purpose of this study to provide preliminary data to effective halitosis control. Methods : A survey was carried out the self-perception of causative factors of halitosis in 98 female college students in Chungnam province. In addition, the levels of oral gas and breath gas were measured by use of the B&B checker, and an analysis was made of the correlation between halitosis and obsessive-compulsive disorder (OCD). Results : 1. Subjective halitosis awareness degree different degree of dryness, 'None', 'some', 'little' people who feel as the 'little fly' (68%), 78.3%, 70% was higher (p<0.05), halitosis interest 'very worried', 'worry', 'normal' person with a' not at all 'to 58.3% higher (p<0.01). 2. In regard to OCD severity, 49.0%, 34.7% and 16.3% were found to be mild, moderate and severe respectively. Halitosis tended to be severe in proportion to OCD severity, which was statistically significant (p<0.05). 3. Oral gas had a positively correlation with breath gas (r=0.329, p<0.01), but had a negative one with OCD severity (r=0.204, p<0.05). Conclusions : Symptoms of oral dryness and halitosis interest were associated with self-perception of halitosis. The levels of oral gas and breath gas were in inverse proportion to OCD severity. Hereat, it needs to analyze psychogenic factors properly as regards the diagnosis or treatment of halitosis.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.6
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• pp.63-74
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• 2005

In Electronic Commerce, the latest most of the personalized recommender systems have applied to the collaborative filtering technique. This method calculates the weight of similarity among users who have a similar preference degree in order to predict and recommend the item which hits to propensity of users. In this case, we commonly use Pearson Correlation Coefficient. However, this method is feasible to calculate a correlation if only there are the items that two users evaluated a preference degree in common. Accordingly, the accuracy of prediction falls. The weight of similarity can affect not only the case which predicts the item which hits to propensity of users, but also the performance of the personalized recommender system. In this study, we verify the improvement of the prediction accuracy through an experiment after observing the rule of the weight of similarity applying Vector similarity, Entropy, Inverse user frequency, and Default voting of Information Retrieval field. The result shows that the method combining the weight of similarity using the Entropy with Default voting got the most efficient performance.

• The Transactions of the Korea Information Processing Society
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• v.6 no.9
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• pp.2422-2430
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• 1999

In this paper, we propose a new method for automatic classification of web documents using the degree of correlation between words. First, we select keywords from term frequency and inverse document frequency (TF*IDF) and compute the degree of relevance between the keywords in the whole documents,, using the probability model word that was closely connected with them and create a profile that characterizes each class. Finally, if we repeat the above process until lower than threshold value, we will make several profiles which are in keeping with users concern. And, we classified each document with the profiles and compared these with those of other automatic classification methods.

• Environmental and Resource Economics Review
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• v.28 no.4
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• pp.497-526
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• 2019

The importance of "decoupling" to maintain economic growth and reduce greenhouse gases is emerging as the world has been mandated to reduce greenhouse gases since the 2015 Paris Agreement. This study covered 63 countries from 1980 to 2014 and analyzed the main characteristics and causes of decoupling phenomenon between economic growth and carbon emissions. In this study, the degree of decoupling was measured every five years. The analysis found that the decoupling rate of OECD countries and countries with large incomes was high, and that the decoupling phenomenon has accelerated worldwide since the 2000s. However, the degree of decoupling was different depending on the national characteristics. According to the results of dynamic panel model, the growth rate of manufacturing and the proportion of exports hampered decoupling, while the proportion of human capital and renewable energy had a positive effect on decoupling. Also income had a inverse U-shape non-linear effect on decoupling.

• Journal of Advanced Navigation Technology
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• v.23 no.3
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• pp.258-263
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• 2019

OFDM is popular digital communication method due to its immunity to multipath fading and capability of high speed data transmission, but it has disadvantage of high PAPR in transmission signal when many subcarrier modulated signal are added to the same phase. When frequency domain high amplitude impulse is inserted before IFFT in OFDM transmitter, the PAPR of OFDM signal in tme domain can be effectively reduced. In this paper, the degree of PAPR improvement of OFDM communication system with CQAM subcarrier modulation is analysed by adopting impulse insertion technique before IFFT of transmitter. Furthermore, it is verified that additional PAPR performance improvement can be obtained by finding optimum position of impulse insertion for maximizing PAPR reduction. Through computer simulation, the degree of PAPR improvement according to amplitude and position of inserted impulse is superior to conventional technique in OFDM-CQAM system.

• Journal of Korea Society of Industrial Information Systems
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• v.14 no.4
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• pp.16-29
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• 2009

This paper investigates the kinematic and dynamic analysis of a spherical three degree of freedom parallel joint module, which is used in the exercise equipment for balance and leg-strength improvement of aged people. The joint module has three dyads which consist of two links and three revolute joints, and their all joints intersect at the global point located at the module's center. The paper shows the explicit mathematical procedure for deriving the closed form solutions in the inverse and forward position analysis of this parallel joint module. In velocity and acceleration analysis, we derived relations for joint velocities and accelerations of dyads and rotational velocity and acceleration of the top plate. For applying this module to rehabilitation exercise, we determined the dynamic model of the Korean males in their 50s and examined the model's results by dynamic model simulation.

• Asia Marketing Journal
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• v.14 no.4
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• pp.167-188
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• 2013

In today's society with its emphasis on unlimited information access, control of available information about high-technology products is often vital to their success. When a product is released, consumers may initially be attracted through information about its remarkable internal and external features. They may also perceive a degree of congruence between their own personalities and the product image as more information becomes available over time. Consumers' changing impressions of the product may influence personality congruence negatively or positively. These changes and their effects on preference for high-technology products are the focus of this paper. A survey was given to a sample of 206 students at K University to investigate the degree to which consumer behavior can be influenced by personality congruence. The need for clear and definite product knowledge in this process and the effect of product information on preference were also investigated. Three analyses were conducted. The results of Analysis 1 showed the influence of personality congruence on preference for high-technology products. Judgments about personality congruence were based on non-compensatory rather than compensatory information processing. The respondents considered certain aspects of a product's personality rather than the product as a whole when making preference decisions. The results of Analysis 2 indicated that when less information was available about a product, consumers who perceived high personality congruence with the product tended to have higher preference for it compared to those who perceived low personality congruence with the product. On the other hand, when consumers were given more information, no difference was observed in the impact of personality on preference between perceived high and low personality congruence. Lastly, the results of Analysis 3 showed that when consumers with high need for closure (NFC) perceived high congruence between their own personalities and a product, objective information regarding the product was not used in decision-making: instead, judgments about the product were based on perceived personality congruence. On the other hand, high-NFC consumers who perceived low personality congruence between themselves and the product tended to require more information about the product in order to give it a positive evaluation. In contrast, low-NFC consumers who perceived high personality congruence felt comfortable with large amounts of information. For low-NFC consumers who perceived low congruence, the level of information had no influence on preference.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.26 no.1
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• pp.31-39
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• 2022

In patients with neuroendocrine tumors with liver metastases (NETLMs), complete resection of both the primary and liver metastases is a potentially curative option. When complete resection is not possible, debulking of the tumour burden has been proposed to prolong survival. The objective of this systematic review was to evaluate the effect of curative surgery (R0-R1) and debulking surgery (R2) on overall survival (OS) in NETLMs. For the subgroup of R2 resections, outcomes were compared by the degree of hepatic debulking (≥ 90% or ≥ 70%). A systematic review of the literature was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines using PubMed, Medline, CINAHL, Cochrane, and Embase databases. Hazard ratios (HRs) were estimated for each study and pooled using a random-effects inverse-variance meta-analysis model. Of 538 articles retrieved, 11 studies (1,729 patients) reported comparisons between curative and debulking surgeries. After pooling these studies, OS was found to be significantly shorter in debulking resections, with an HR of 3.49 (95% confidence interval, 2.70-4.51; p < 0.001). Five studies (654 patients) compared outcomes between ≥ 90% and ≥ 70% hepatic debulking approaches. Whilst these studies reported a tendency for OS and progression-free survival to be shorter in those with a lower degree of debulking, they did not report sufficient data for this to be assessed in a formal meta-analysis. In patients with NETLM, OS following surgical resection is the best to achieve R0-R1 resection. There is also evidence for a progressive reduction in survival benefit with lesser debulking of tumour load.