• International Journal of Precision Engineering and Manufacturing
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• v.1 no.1
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• pp.106-110
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• 2000

The researches classifying the artificial flaws in welding parts are performed using the pattern recognition technology. For this purpose the signal pattern recognition package including user defined function is developed and the total procedure is made up the digital signal processing, feature extraction, feature selection, classfier design. Specially it is composed with and discussed using the ststistical classfier such as the linear discriminant function classfier, the empirical Bayesian classfier.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1960-1963
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• 2002

Transmit diversity schemes we an effective capacity improvement method for down link of wideband code division multiple access (W-CDMA) systems. In this paper, we propose to use transmit antenna subset selection scheme in conjunction with closed loop transmit adaptive array (TxAA). The proposed scheme selects N$\_$s/ optimum antennas among N$\_$${\gamma}$/(>N$\_$s/) transmit antennas in order to maximize diversity gain from selected antennas, and also reduces the cost of RE chains by employing two different types of RF modules fur the selected and the unselected antenna group, respectively. Computer simulation results show performance improvement by the proposed scheme over the conventional TxAA when considering up link control information feedback.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.249-251
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• 2014

This paper proposes a channel diversity based load-balancing cross-layer routing scheme for Wireless Mesh Networks (WMNs). The proposed scheme deals with channel diversity phase and load balancing phase in WMNs. Channel diversity factor $metric_{ch-d}$ and load balancing factor $f_{load}$ are defined and employed cooperatively as a combined path selection policy.

• Structural Engineering and Mechanics
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• v.70 no.5
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• pp.513-524
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• 2019

This study proposed an improved particle swarm optimization (IPSO) method ensemble with kriging model for model updating. By introducing genetic algorithm (GA) and grouping strategy together with elite selection into standard particle optimization (PSO), the IPSO is obtained. Kriging metamodel serves for predicting the structural responses to avoid complex computation via finite element model. The combination of IPSO and kriging model shall provide more accurate searching results and obtain global optimal solution for model updating compared with the PSO, Simulate Annealing PSO (SimuAPSO), BreedPSO and PSOGA. A plane truss structure and ASCE Benchmark frame structure are adopted to verify the proposed approach. The results indicated that the hybrid of kriging model and IPSO could serve for model updating effectively and efficiently. The updating results further illustrated that IPSO can provide superior convergent solutions compared with PSO, SimuAPSO, BreedPSO and PSOGA.

• Journal of the Korean Society for information Management
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• v.33 no.3
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• pp.239-262
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• 2016

This study aims to explore ways to improve self-censorship tendency in teacher librarians by identifying factors that influence the self-censorship which appears during collection development in elementary school libraries. For this purpose, first, we examined the concept of self-censorship through a review of related literature, then carried out a series of in-depth interviews as a pilot study to develop a questionnaire, which was used for a questionnaire survey. Finally, the survey data was analyzed statistically with SPSS 21.0, a statistical package. As a result, we have discovered statistically significant relationships between self-censorship and the characteristics in collection development policies, school library committees, and the complaints related with the library collections. Based on these results, the factors on the self-censorship were identified in the perception of the school librarians. Based on these results, we suggest to reinforce the function of review and approval of book selection in the school library committee, developed and approved a collection development policy include guidelines for dealing with users' complaints related to library collection, and stipulated a regulation for school library operation to remove inappropriate books from the library collection.

• Journal of the Korean Society for information Management
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• v.30 no.3
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• pp.7-21
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• 2013

The study examines two aspects that relate to undergraduates' selection and use of information sources for their academic assignments: (1) sources perceived useful vs. sources frequently used, and (2) source characteristics considered important as selection criteria vs. selection criteria used as reflected in characteristics of frequently used sources. A survey of 251 undergraduate students attempted to address the gaps between what students think they should do and what they actually do with regard to source selection. Characteristics of frequently used sources were analyzed to find out the criteria used for source selection. Friends/family were among the frequently used sources although they were not perceived as useful. Unlike other sources suffering gaps between the perceived usefulness and the use behavior, Web sources were the ones not only perceived most useful but also used most frequently. When the important selection criteria were compared with the characteristic of sources used often, students did not seem to actually use the selection criteria they thought important. While students considered some characteristics related to information quality (e.g., accuracy, comprehensiveness) as important criteria for source selection, the actual criteria they applied for choosing information sources could be described as 'convenient' or 'accessible' (e.g., efficient/time saving, easy to use, familiar, accessible). Based on the findings, suggestions were made to help bridge such gaps through information literacy programs and information systems design.

• Proceedings of the Zoological Society Korea Conference
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• 2000.10a
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• pp.261.2-262
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• 2000

No Abstract, See Full Text

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.510-516
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• 2008

In ubiquitous environment, there are no limits to utilize networks whenever and wherever you are. That pervasive networks are combined with the information devices and then create various services such as car navigation of LBS(location based service) and DMB(Digital Multimedia Broadcasting). As these kinds of services are getting more various, the complexity is also getting higher and ultimately the convergence will make people feel frustrated. One of the solutions is Context-Awareness[1] technology. User interface with context-awareness filters unnecessary information and prevents users from being blocked due to the massive information. In this paper, we describe the seamless service system based on location-awareness, which is a type of context-awareness. We developed the system based on UPnP AV Framework. This system provides the automatic terminal device selection for the nomadic user. The system establishes new connections for the ongoing streaming playback session with the new AV devices without substantial loss of playback so that the user can enjoy the seamless service. The AV device selection based on the user's location needs no user's intervention or notification so it achieves the improvement of usability and complexity.

• Korean Management Science Review
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• v.32 no.1
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• pp.15-33
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• 2015

Under complete information, introducing additional constraints to a portfolio will have a negative impact on performance. However, real-life investments inevitably involve use of error-prone estimations, such as expected stock returns. In addition to the reality of incomplete data, investments of most Korean domestic equity funds are regulated externally by the government, as well as internally, resulting in limited maximum investment allocation to single stocks and risk free assets. This paper presents an investment framework, which takes such real-life situations into account, based on a newly developed portfolio selection model considering realistic constraints under incomplete information. Additionally, we examined the effects of additional constraints on portfolio's performance under incomplete information, taking the well-known Samsung and SK group stocks as performance benchmarks during the period beginning from the launch of each commercial fund, 2005 and 2007 respectively, up to 2013. The empirical study shows that an investment model, built under incomplete information with additional constraints, outperformed a model built without any constraints, and benchmarks, in terms of rate of return, standard deviation of returns, and Sharpe ratio.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.3
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• pp.1425-1440
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• 2017

In wireless communications, antenna selection (AS) is a widely used method for reducing comparable cost of multiple RF chains in MIMO systems. As is well known, most of literatures on combining AS with MIMO techniques concern linear modulations such as phase shift keying (PSK) and quadrature amplitude modulation (QAM). The combination of CPM and MIMO has been considered an optimal choice that can improve its capacity without loss of power and spectrum efficiency. The aim of this paper is to investigate joint transmit and receive antenna selection (JTRAS) in CPM MIMO systems. Specifically, modified incremental and decremental JTRAS algorithms are proposed to adapt to arbitrary number of selected transmit or receive antennas. The computational complexity of several JTRAS algorithms is analyzed from the perspective of channel capacity. As a comparison, the performances of bit error rate (BER) and spectral efficiency are evaluated via simulations. Moreover, computational complexity of the JTRAS algorithms is simulated in the end. It is inferred from discussions that both incremental JTRAS and decremental JTRAS perform close to optimal JTRAS in BER and spectral efficiency. In the sense of practical scenarios, adaptive JTRAS can be employed to well tradeoff performance and computational complexity.