• MALSORI
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• no.21_24
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• pp.144-175
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• 1992

This paper aims to discuss determining factors of Korean allophones and to formulate and classify Korean allophonic rules systematically. The relationship between allophones and coarticulation, the most. influential factor of allophonic variation, is thoroughly investigated. Other factors -- speech tempo and style, dialect, and social factors such as age, set, class etc. -- are also briefly discussed. Allophonic rules are classified into two groups -- 3) those relevant to coarticulation and 2) those irrelevant to coarticulation. Rules of the first group are further classified into four subgroups according to the directionality of the coarticulation. Each allophonic nile formulation is explained and discussed in detai1. The allophonic rules formulated and classified in this paper are 1) Devoicing of Voiced Consonants, 2) Devoicing of Vowels, 3) Nasal Approach and Lateral Approach, 4) Uvularization, 5) Palatalization, 6) Voicing of Voiceless Lax Consonants, 7) Frication, 8) Labialization, 9) Nasalization, 10) Release Withholding and Release Masking, 11) Glottalization, 12) Flap Rule, 13) Vowel Weakening, and 14) Allophones of /ㅚ, ㅟ, ㅢ/ (which are realized as diphthongs or as monophthongs depending on phonetic contexts).

• Journal of KSNVE
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• v.4 no.2
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• pp.187-198
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• 1994

This study is to describe the effects of the duct termination conditions conditions upon the active noise attenuation system. The adaptive filtering algorithm using FIR filter is implemented for duct noise attenuation. To avoid the instability caused by the acoustic feedback, two methods are considered. One is to use a compensating FIR filter. The other is to utilize uni-directional detecting microphone and uni-directional control speaker. Experimental results show that the reflections of sound from duct terminations greatly reduce the performance of ANC system. The directionality of detecting microphone and control speaker is a major factor to decide ANC performance. When there are some reflections from both duct terminations, the noise attenuation using finite FIR filter is not enough to model the duct plant. Especially, the reflection from the upstream termination reduces the noise attenuation in the frequencies related to the distance between control speaker and upstream termination. The performance of the noise attenuation is found to be largely enhanced by using uni-directional coupler, both on detecting microphone and control speaker, even if the duct system has an arbitrary termination conditions.

• Journal of Information Technology Applications and Management
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• v.22 no.4
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• pp.39-57
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• 2015

Online marketplace represents the triad relationship among the consumer, the intermediary, and the seller community. However there have been a limited number of studies conducted with the view of the triad relationship, which have produced contradictory and mixed results. The purpose of this study is (1) to find trust factors affecting consumers' transaction intention-trust in intermediary and trust in community of sellers, and (2) to investigate the directionality of trust transfer between those factors. To do this, the study sets and tests a bidirectional model. Based on the study results, the study discusses that both trust in intermediary and trust in community of sellers are important to consumers' transaction decision in online marketplace, and trust transfer in online marketplace flows from intermediary to community of sellers.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.46-49
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• 2000

An iterative deblocking algorithm for DCT-compressed images using two-dimensional FIR filters adapted for local directionality of each block, is proposed. First, we introduce a set of simple lowpass filters, which are adapted for edges of different angles. In conventional deblocking methods based on lowpass-filtering and convex projections, a single filter is applied to a whole image. In the proposed method, on the other hand, a suitable filter is chosen out of the directional filters designed previously in every subimage (typically $8{\times}8$ block). Experimental results indicate that adaptive filtering improves PSNR at each iteration.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.76-77
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• 2019

Currently, there is a lack of studies on the directionality of architectural engineering education. This study has analyzed the opening and operation of courses relating to building construction in Korea universities. It was researched that the most common building construction courses opened in universities were 'building construction' and 'materials.' Courses are also being opened in universities by reflecting social demands. Upon analysis of the operation of the educational process of building construction, it was displayed that projects and examinations were conducted as the methods of assessment in courses at many universities. Additionally, there were universities that included quizzes and discussions in their methods of assessment. This study is expected to be used as data for studying an innovative means of educating architecture.

• Smart Structures and Systems
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• v.17 no.6
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• pp.1055-1065
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• 2016

An anisotropic ultrasonic transducer is proposed for Lamb wave applications, such as passive damage or impact localization based on ultrasonic guided wave theory. This transducer is made from a PMNPT single crystal, and has different piezoelectric coefficients $d_{31}$ and $d_{32}$, which are the same for the conventional piezoelectric materials, such as Lead zirconate titanate (PZT). Different piezoelectric coefficients result in directionality of guided wave generated by this transducer, in other words, it is an anisotropic ultrasonic transducer. And thus, it has different sensitivity in comparison with conventional ultrasonic transducer. The anisotropic one can provide more information related to the direction when it is used as sensors. This paper first shows its detailed properties, including analytical formulae and finite elements simulations. Then, its application is described.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.406-411
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• 2003

This paper deals with the effect of laser material processing on the EMU production technique. Material processing with lasers takes advantage of all the characteristics of laser light. The high energy density and directionality achieved with lasers permits strong localized heat- or photo-treatment of materials with spatial resolution below one micrometer. The pulsed and mono-chromatic light allows the control of depth of heat treatment or selective excitation. The laser beam can be moved to process large areas, is a sterile tool and is no subject to wear and tear. Using laser processing have taken more interests in EMU production for improving the rigidity, weight reduction, crash durability, and cost savings so that their application to auto-bodies has been increased.

• Korean Journal of Materials Research
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• v.24 no.1
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• pp.1-5
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• 2014

This study is experimentally investigated whether or not a relationship exists between the mechanical properties and damping capacity of cold-rolled 316 L stainless steel. Deformation-induced martensite was formed with surface relief and directionality. With the increasing degree of deformation, the volume fraction of ${\varepsilon}$-martensite increased, and then decreased, while ${\alpha}^{\prime}$-martensite increased rapidly. With an increasing degree of deformation, tensile strength was increased, and elongation was decreased; however, damping capacity was increased, and then decreased. Tensile strength and elongation were affected in the ${\alpha}^{\prime}$-martensite; hence, damping capacity was influenced greatly by ${\varepsilon}$-martensite. Thus, there was no proportional relationship between strength, elongation, and damping capacity.

• Journal of Communications and Networks
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• v.18 no.3
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• pp.446-459
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• 2016

In this paper, we propose virtual direction multicast (VDM) for video multicast applications on peer-to-peer overlay networks. It locates the end hosts relative to each other based on a virtualized orientation scheme using real-time measurements. It builds multicast tree by connecting the nodes, which are estimated to be in the same virtual direction. By using the concept of directionality, we target to use minimal resources in the underlying network while satisfying users' quality expectations. We compare VDM against host multicast tree protocol.We simulated the protocol in a network simulator and implemented in PlanetLab. Results both from simulation and PlanetLab implementation show that our proposed technique exhibits good performance in terms of defined metrics.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3086-3088
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• 1999

An ultrasonic sensor is one of most popular sensor used to navigate mobile robots within environments containing obstacles. But many navigation algorithm have studied because of the drawback of ultrasonic sensor such that poor directionality, frequent misreadings, specular reflections. Also, the most crucial drawback of this algorithm, that is VFF, VFM, EDM, PFM, WFM, GFM etc. has been that the mobile robot may become trapped in a local minimum. In this paper, we present a theoretical study of a navigation algorithm which integrals a heuristic-search local minimum (or trap) recovery method with a vector-field based method to maneuver cylindric mobile robots in unknown of unstructured environments. Also, an autonomous mobile robot uses dead-reckoning to estimate the current position and orientation of a mobile robot.