• Korean Management Science Review
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• v.16 no.2
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• pp.125-135
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• 1999

This paper presents a framework for the hierarchical PPC(Production Planning and Control) in make-to-order environment with job shop. The characteristics of the environment are described as : 1) project with non-repetitive and individual production, 2) short delivery date, 3) process layout with large scales manufacturing. 4) job shops. The PPC in a make-to-order typically are organized along hierarchical fashions. A model is proposed for the hierarchical job shop scheduling based on new concepts of production system, work and worker organization. Then, a new integrated hierarchical framework is also developed for the PPC based on concepts of the proposed job shops scheduling model. Finally, the proposed framework has been implemented in the Electric Motor Manufacturing and the results showed good performance.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.1
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• pp.88-95
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• 1998

In this paper, we introduce a new DCT based hierarchical finite state vector quantization. Our proposed scheme uses difference of DCT coefficients to find a representative vector, and classifies image blocks into different hierarchical levels depending on their structural characteristics, and uses different coding rates and different number os state codebooks at each hierarchical levels. As a result, we obtained reconstructed images having satisfiable quality objectively.

• Journal of Advanced Navigation Technology
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• v.16 no.6
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• pp.975-981
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• 2012

The SNR estimation performance of hierarchical 16QAM system, which is adopted to simultaneous transmission or efficient image transmission system, is analyzed. Hierarchical 16QAM is modulation system which has different constellation shape from conventional QAM and can provide users with high quality and low quality of data services simultaneously by controlling hierarchical modulation parameter. Assuming AWGN channel, SNR estimation performance characteristics are investigated considering hierarchical modulation parameter and type of constellation points. From simulation results, it is found that constellation point showing superior SNR estimation performance relative to other points is exist. Also, it is known that according to hierarchical modulation parameter, SNR estimation range with more accurate estimation performance is divided.

• Journal of the Society of Disaster Information
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• v.14 no.2
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• pp.182-193
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• 2018

Purpose: The purpose of the study is to analyze the relationship between travel behavior and urban spatial characteristics in a hierarchical manner. Method: This study analyzed the relationship between traffic patterns and urban spatial characteristics for 83 cities in Korea by using a hierarchical linear model. Results: It was found that the urban spatial characteristics influenced the choice of transportation mode and travel time with personal attributes. However, the degree of influence on the choice of the means and the time required is relatively low through the policy of changing the city attribute, so the policy effect of mobilizing the land use policy for the traffic is theoretically, but the scale is not bigger than expected. Conclusion: In high density or the bigger scale of the city, the mass transportation system is widely supplied and used, but it does not overcome the drawback that it takes more time than the autos.

• Korean Journal of Childcare and Education
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• v.14 no.3
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• pp.97-115
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• 2018

Objective: This study aimed to analyse the influence of young children's playfulness at home and class characteristics on their playfulness at kindergarten. Methods: Twenty eight classes of 3, 4 and 5 year olds in Gyeonggi and Chungbuk provinces were recruited. Participants of this study were mothers and head teachers of the children of recruited classes. Analyses was implemented using hierarchical linear modeling with HLM 7.0. Results: Differences were found in children's playfulness at kindergarten according to their classes. Individual characteristics including, gender, age and playfulness at home were shown to have significant influences on playfulness at kindergarten, while relevance of variable class characteristics to playfulness at kindergarten was not observed. Conclusion/Implications: It is concluded that playfulness of children is more related to playfulness at home rather than class characteristics, implying the strong characteristic of playfulness as an individual trait.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.46
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• pp.173-180
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• 1998

In conventional probability-based quality evaluation of products with qualitative characteristics, many factors that affect the evaluation are not easily represented quantitatively, because the relation between reliability of human evaluator and each of these factors is not clear. In order to evaluate the quality of product with qualitative characteristics quantitatively, in this paper, the relation is represented as the shape of possibility distribution function of fuzzy set on the interval [0,1]. Furthermore, fuzzy reasoning is used to obtain the estimates of quality characteristics. And, it is supposed that many quality characteristics affected by the above factors are connected with the final characteristic through hierarchical structures. Finally, using the estimates gained from the final evaluation, qualitative characteristics are evaluated by use of concept of pattern recognition.

• Journal of Korean Port Research
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• v.13 no.1
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• pp.79-86
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• 1999

This paper deals with the evaluation problem of complex systems by introducing a fuzzy approach. The authors are functionally supposing a hierarchical structure model of a complex system and give light on the following problems. First for the purpose of clarifying the characteristics of measures the property and differences between two method such as linear and fuzzy viewpoint are discussed through two level-down evaluation process. Second the integrated evaluation process which keeps reversibility between hierarchical levels is discussed and obtained some necessary conditions for reversibility of fuzzy evaluation. From these results it is expected that the fuzzy approach overcomes partly the limitation of reductionism at the hierarchical evaluation of complex systems.

• Proceedings of the Korean Society for Language and Information Conference
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• 2007.11a
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• pp.321-329
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• 2007

This paper reports on the application of network analysis approaches to investigate the characteristics of graph representations of Japanese word associations. Two semantic networks are constructed from two separate Japanese word association databases. The basic statistical features of the networks indicate that they have scale-free and small-world properties and that they exhibit hierarchical organization. A graph clustering method is also applied to the networks with the objective of generating hierarchical structures within the semantic networks. The method is shown to be an efficient tool for analyzing large-scale structures within corpora. As a utilization of the network clustering results, we briefly introduce two web-based applications: the first is a search system that highlights various possible relations between words according to association type, while the second is to present the hierarchical architecture of a semantic network. The systems realize dynamic representations of network structures based on the relationships between words and concepts.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.2901-2905
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• 2014

The hierarchical-structured $LiFePO_4$ cathode materials were synthesized by one-step microwave synthesis, and their electrochemical properties were investigated. Addition of citric acid during the reaction lead to the formation of hierarchical structured $LiFePO_4$, which has both nano- and micron-characteristics advantageous for energy density and electrode fabrication. Adjusting the molar ratio of Fe to citric acid enhanced the electrochemical properties of $LiFePO_4$.

• Korean Journal of Childcare and Education
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• v.20 no.2
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• pp.83-103
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• 2024

Objective: This study aimed to investigate the effects of children's characteristics and childcare teachers' attributes on the frequency and level of imaginative play in two-year-old classrooms. Methods: The study involved 191 toddlers, their mothers, and 32 teachers from childcare centers. Toddler characteristics encompassed temperament along with demographic variables such as gender and age. Teacher' attributes related to play included playfulness, play-support belief, and interactions with toddlers. Data analysis was conducted using SPSS 22.0 and HLM 8.2 software, employing basic analysis, hierarchical linear analysis, and hierarchical regression analysis. Results: First, as toddlers' age increased, both the frequency and level of their imaginative play increased. Second, individual-level model analysis revealed a positive effect of toddlers' extroversion on the level of imaginative play. Third, the class-level model results indicated that teachers' emotions had a negative effect, whereas their encouragement positively influenced the level of imaginative play. Conclusion/Implications: The significance of this study lies in its utilization of a multilayered model analysis, which offers a more robust examination of variable influences by accounting for hierarchical data structures.