• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.5-8
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• 2003

This paper presents a methodology to be able to select an appropriate RP system that suits the end use of a part. Evaluation factors used in process selection include major attributes such as accuracy, roughness, strength, elongation, part cost and build time that greatly affect the performance of RP systems. Crisp values such as accuracy and surface roughness are obtained with a new test part developed. The test part is designed with conjoint analysis to reflect users' preference. The part cost and build time that have approximate ranges due to cost and many variable parameters are presented by linguistic values that can be described with triangular fuzzy numbers. Based on the evaluation values obtained, an appropriate RP process for a specific part application is selected by using the modified TOPSIS(Technique of Order Preference by Similarity to Ideal Solution) method. It uses crisp data as well as linguistic variables, and each weight on the alternatives is assigned by using pair-wise comparison matrix. The ranking order helps the decision making of the selection of RP systems.

• Journal of Energy Engineering
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• v.15 no.1 s.45
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• pp.74-81
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• 2006

In this study, on the basis of an analytic hierarchy process (AHP) method and through a questionnaire on subjective preference and importance, various power supply systems were comprehensively compared with multiple decision criteria such as environmental, social, healthy, and economic viewpoints and then overall priority was assessed. When a decision-making problem is modelled by a hierarchy structure, the AHP method is regarded as a useful tool for extracting subjective opinions via the aforementioned questionnaire. Here, the overall preferences were obtained by linearly aggregating weighting vector and preference matrix. The energy systems such as nuclear, coal, and LNG power plants were selected because they took share over 90% of domestic electricity supply in Korea. Furthermore, wind power and photovoltaic solar systems were included as representative renewable energy systems in Korea. According to the results of this demonstration study, the following comprehensive comparison indicators were yielded: 1) weighting factors for 4 types of main criteria as well as for 11 types of sub-criteria; 2) preference valuation for 7 types of energy systems under consideration; 3) overall score for each energy systems.

• Archives of design research
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• v.19 no.2 s.64
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• pp.81-90
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• 2006

Pedestrians perceive differently from the sideway views or the exteriors of the buildings on the way to their destinations. Therefore, the navigation experience can become much different when the path was chosen based on the individual's preference from it is not. By focusing on the effects of the individual pedestrian' path choice on their navigation, this paper presents an algorithm designed for pedestrians to be able to explore their preferred path and proposes a prototype of navigation system based on the algorithm. The navigation support system searches for the best path upon their individual preferences and information of the destination. The system provides the process of retrieving the final path via the pedestrian-support system interaction. The path retrieval is peformed with the combinational matrix of keywords that are formulates Fuzzy theory from the correlations between the terms describing preferences used in the path preference survey. This paper presents the potentials of the path finding method tailored to pedestrians' preferences by a simulation of the proposed path retrieval algorithm.

• Journal of Intelligence and Information Systems
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• v.9 no.2
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• pp.51-63
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• 2003

Collaborative filtering is one of the methodologies that are most widely used for recommendation system. It is based on a data matrix of each customer's preferences of products. There could be a lot of missing values in such preference data matrix. This incomplete data is one of the reasons to deteriorate the accuracy of recommendation system. There are several treatments to deal with the incomplete data problem such as case deletion and single imputation. Those approaches are simple and easy to implement but they may provide biased results. Multiple imputation method imputes m values for each missing value. It overcomes flaws of single imputation approaches through considering the uncertainty of missing values. The objective of this paper is to suggest multiple imputation-based collaborative filtering approach for recommendation system to improve the accuracy in prediction performance. The experimental works show that the proposed approach provides better performance than the traditional Collaborative filtering approach, especially in case that there are a lot of missing values in dataset used for recommendation system.

• Journal of Korea Society of Digital Industry and Information Management
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• v.19 no.3
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• pp.221-232
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• 2023

In this paper, we propose a recommendation system based on the latent factor model using matrix factorization, which is one of the most commonly used collaborative filtering algorithms for recommendation systems. In particular, by introducing the concept of creating a list of recommended content and a list of non-preferred recommended content, and removing the non-preferred recommended content from the list of recommended content, we propose a method to ultimately increase the satisfaction. The experiment confirmed that using a separate list of non-preferred content to find non-preferred content increased precision by 135%, accuracy by 149%, and F1 score by 72% compared to using the existing recommendation list. In addition, assuming that users do not view non-preferred content through the proposed algorithm, the average evaluation score of a specific user used in the experiment increased by about 35%, from 2.55 to 3.44, thereby increasing user satisfaction. It has been confirmed that this algorithm is more effective than the algorithms used in existing recommendation systems.

• Journal of Korea Society of Industrial Information Systems
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• v.18 no.1
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• pp.47-58
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• 2013

This study offers a $3{\times}2$ matrix on the development method pursuant to the level of readiness and necessity for IS of SMEs, and the Delphi method survey through the assistance of a panel of IT experts was employed. Upon analyzing the results, in all rounds, the 1st quadrant and 2nd quadrant resulted in a preference for leasing methods (ASP/SaaS) and the other quadrants resulted in a preference for outsourcing. Quadrants closer to the 1st quadrant showed a preference for leasing methods (ASP/SaaS) and quadrants closer to the 6th quadrant showed a preference for outsourcing. In the case of the IS implementation for the entire company, all three levels of readiness resulted in a preference for outsourcing. The point in which the implementation method changed depending on the level of readiness was when unit systems were implemented, and among the implementation methods, in-house development showed the lowest results.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.2
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• pp.164-171
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• 2006

Recently Digital multimedia broadcasting (DMB) has been available as a commercial service. The users sometimes have difficulty in finding their preferred multimedia contents and need to spend a lot of searching time finding them. They are even very likely to miss their preferred contents while searching for them. In order to solve the problem, we need a method for recommendation users preferred only minimum information. We propose an algorithm and a system for recommending users' preferred contents using preference transition probability from user's usage history. The system includes four agents: a client manager agent, a monitoring agent, a learning agent, and a recommendation agent. The client manager agent interacts and coordinates with the other modules, the monitoring agent gathers usage data for analyzing the user's preference of the contents, the learning agent cleans the gathered usage data and modeling with state transition matrix over time, and the recommendation agent recommends the user's preferred contents by analyzing the cleaned usage data. In the recommendation agent, we developed the recommendation algorithm using a user's preference transition probability for the contents. The prototype of the proposed system is designed and implemented on the WIPI(Wireless Internet Platform for Interoperability). The experimental results show that the recommendation algorithm using a user's preference transition probability can provide better performances than a conventional method.

• Phonetics and Speech Sciences
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• v.14 no.2
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• pp.1-10
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• 2022

A wh-phrase positioned in an embedded clause can be interpreted as having a matrix scope if the sentence is produced with proper prosodic structures such as the wh-intonation. In a previous experiment, a sentence with a wh-phrase in an embedded clause was given to 40 speakers of Gyeongsang Korean. A script containing the sentence was provided to induce a matrix scope interpretation for the wh-phrase. These 40 utterances were prepared as stimuli for a perception test to verify whether the wh-phrases in the stimuli were perceived as having matrix scopes. Each utterance was played thrice to 24 subjects. The results showed that more than half of the 72 responses indicated a preference for an embedded scope rather than a matrix scope in 20 of the utterances. A multiple linear regression analysis showed that the matrix scope responses were best predicted by the magnitude of the pitch prominence in a prosodic word consisting of an embedded verb and a complementizer. The pitch prominence was calculated by subtracting the fundamental frequency (F0) at the right edge of the prosodic word from the peak F0 in the same prosodic word. The smaller the magnitude, the more matrix responses there were. These results suggest that the categorical perception of wh-scopes is based on the magnitude of pitch prominence.

• Journal of the Korea Society of Computer and Information
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• v.20 no.5
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• pp.107-112
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• 2015

This paper proposes a simplified algorithm devised to obtain optimal solution to the marriage problem. In solving this problem, the most widely resorted to is the Gale-Shapley algorithm with the time complexity of $O({\mid}V{\mid}^2{\mid}E{\mid})$. The proposed algorithm on the other hand firstly constructs a $p_{ij}$ matrix of inter-preference sum both sexes' preference over the opposite sex. Secondly, it selects $_{min}p_i$ from each row to establish ${\mid}p_{.j}{\mid}{\geq}2,j{\in}S$, ${\mid}p_{.j}{\mid}=1$, $j{\in}H$, ${\mid}p_{.j}{\mid}=0$, $j{\in}T$. Finally, it shifts $_{min}\{_{min}p_{ST},p_{SH}+p_{HT\}$ for $_{min}P_{ST}$ of $S{\rightarrow}T$ and $p_{SH}+p_{HT}$, $p_{HT}<_{min}p_{ST}$ of $S{\rightarrow}H$, $H{\rightarrow}T$. The proposed algorithm has not only improved the Gale-Shapley's algorithm's complexity of $O({\mid}V{\mid}^2{\mid}E{\mid})$ to $O({\mid}V{\mid}^2)$ but also proved its extendable use on unbalanced marriage problems.

• Journal of Forest and Environmental Science
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• v.30 no.4
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• pp.342-350
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• 2014

Rural people of Sudan are endowed with a deep knowledge concerning the utilization of different tree species. However research on the local knowledge related to tree species utilization still lacks adequate attention. The study objectives were to identify the existing local knowledge related to the utilization of the tree species and the existing threats to the availability of the trees. A total of 300 respondents were selected randomly from Rashad district in Nuba Mountains in 2011. Semi-structured interview, direct observation, group discussion, preference ranking and direct matrix ranking were used to collect the data. The study results revealed that people of Nuba Mountains utilize different tree species for food, medicinal purposes, fodder, firewood, construction and cultural ceremonies. The study results also indicated that the availability of trees is negatively influenced by firewood collection, agricultural expansion, drought, overgrazing and charcoal production. The study concluded that local knowledge has crucial role in tree species utilization in Nuba Mountains. Further researches to document and substantiate the local knowledge on useful tree species are highly recommended.