• Journal of KIISE
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• v.44 no.11
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• pp.1178-1193
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• 2017

It is very important to understand system behaviors in collective pattern for each knowledge domain. However, there are structural limitations to represent collective behaviors because of the size of system components and the complexity of their interactions, causing the state explosion problem. Further composition with other systems is mostly impractical because of exponential growth of their size and complexity. This paper presents a practical method to model the collective behaviors, based on a new concept of domain engineering: behavior ontology. Firstly, the ontology defines each collective behavior of a system from active ontology. Secondly, the behaviors are formed in a quantifiably abstract lattice, called common regular expression. Thirdly, a lattice can be composed with other lattices based on quantifiably common elements. The method can be one of the most innovative approaches in representing system behaviors in collective pattern, as well as in minimization of system states to reduce system complexity. For implementation, a prototype tool, called PRISM, has been developed on ADOxx Meta-Modelling Platform.

• The KIPS Transactions:PartA
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• v.9A no.2
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• pp.197-206
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• 2002

Many researchers have been interested in the optimization of parallel programs through the latency hiding by overlapping the communication with the computation. We ana1yzed overlapping effects in the circular shift communication which is one of the collective communications being frequently used In many data parallel programs. We measured the time which can be possibly overlapped and the time which cannot be overlapped in over all circular shift communication period on an Ethernet switch-based clustered system. The result from each platform nay be used for the input of optimizing compilers. The previous performance models usually have two kinds of drawbacks one is only based on point-to-point communication, so it is not appropriate for analyzing the overall effects of collective communications. The other provides the performance of collective communication, but no overlapping effect. In this paper we extended the previous models and analyzed the experimental results of the extended model.

• Safety and Health at Work
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• v.14 no.1
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• pp.85-92
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• 2023

Background: Presenteeism is closely related to work performance, work quality and quantity, and productivity at work. According to the job demand-control-support model, job demand, job control, and support play important roles in presenteeism. The present study investigated job characteristics profiles based on the job demand-control-support model and identify the association between job characteristics profiles and presenteeism. Methods: This secondary data analysis used the Sixth Korean Working Condition Survey, a nationwide cross-sectional dataset. The study included 25,361 Korean wage workers employed in the workplace with two or more workers. Participants were classified into four job characteristics profiles based on the job demand-control-support model, using latent profile analysis, and logistic regression was performed to examine the association between study variables. Results: Overall, 11.0 % of study participants reported experience of presenteeism in the past 12 months. Age, sex, location, monthly income, shift work, work hours, health problems, and sleep disturbances were significantly associated with presenteeism. The rate of presenteeism was the highest in the passive isolate group. The passive collective, active collective, and low-stain collective groups had a 23.0%, 21.0%, and 29.0% lower likelihood of experiencing presenteeism, respectively, than the passive isolate group. Conclusions: The job demand-control-support profiles and the risk of presenteeism were significantly associated. The most significant group that lowered the experience of presenteeism was the low-strain collective group, which had a low level of demand and high levels of control and support. Therefore, we need a policy to reduce job demand and increase job control and support at the organizational and national levels.

• Journal of the Korean Mathematical Society
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• v.61 no.3
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• pp.565-602
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• 2024

We study the collective behaviors of two second-order nonlinear consensus models with a bonding force, namely the Kuramoto model and the Cucker-Smale model with inter-particle bonding force. The proposed models contain feedback control terms which induce collision avoidance and emergent consensus dynamics in a suitable framework. Through the cooperative interplays between feedback controls, initial state configuration tends to an ordered configuration asymptotically under suitable frameworks which are formulated in terms of system parameters and initial configurations. For a two-particle system on the real line, we show that the relative state tends to the preassigned value asymptotically, and we also provide several numerical examples to analyze the possible nonlinear dynamics of the proposed models, and compare them with analytical results.

• Journal of The Korean Association For Science Education
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• v.34 no.6
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• pp.523-534
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• 2014

This study aimed to develop collective intelligence (CI) based instructional models for teaching socioscientific issues on the basis of intimate collaboration with science teachers, and to investigate the participating teachers' perceptions on the effectiveness of the instructional models. Adapting the ADDIE model, we suggested three types of SSI instructional models (i.e. generative model, exploratory model, and decision-making model). Generative models emphasized the process of brainstorming ideas or possible solutions for SSI. Exploratory models focused on providing students opportunities to explore various SSI cases and diverse perspectives to understand its controversial nature and complexity. Decision-making models encouraged students to negotiate or develop a group-consensus on SSI through the dialogical process. After implementing the instructional models in the science classroom, the teachers reported that CI-based SSI instructional models contributed to encouraging students' active participation and collaboration as well as to improving the quality of their argument or discourses on SSI. They also supported the importance of developing collective consciousness on the issues in the beginning of the SSI class, providing independent time and space for reflecting on their personal values and opinions with scientific evidence, and formulating an atmosphere where they freely exchanged opinions and feedback for constructing better collective ideas.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.8B
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• pp.668-676
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• 2012

In this paper, on the assumption that MPI collective communication function is converted into a group of point-to-point communication functions in the transaction level, an algorithm that optimizes broadcast, scatter and gather function among MPI collective communication is proposed. The MPI hardware engine that operates the proposed algorithm was designed, and it was named the OCC-MPE (Optimized Collective Communication Message Passing Engine). The OCC-MPE operates point-to-point communication by using the standard send mode. The transmission order is arranged according to the algorithm that proposes the most frequently used broadcast, scatter and gather functions among the collective communications, so the whole communication time is reduced. To measure the performance of the proposed algorithm, the OCC-MPE with the Bus Functional Model (BFM) based on SystemC was designed. After evaluating the performance through the BFM based on SystemC, the proposed OCC-MPE is designed by using VerilogHDL. As a result of synthesizing with the TSMC $0.18{\mu}m$, the gate count of each OCC-MPE is approximately 1978.95 with four processing nodes. That occupies approximately 4.15% in the whole system, which means it takes up a relatively small amount. Improved performance is expected with relatively small amounts of area increase if the OCC-MPE operated by the proposed algorithm is added to the MPSoC (Multi-Processor System on a Chip).

• Environmental and Resource Economics Review
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• v.30 no.4
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• pp.557-579
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• 2021

Collective energy is an intermediate stage in energy conversion and has a great influence on the power structure as a distributed power source. However, the problem of the collective energy business has recently emerged due to the worsening profitability of some collective energy operators. This study measured the technical efficiency of major operators through the estimation of the production efficiency of Korean collective energy operators, and based on this, we looked at ways to improve the profit structure of operators. After collecting detailed data from 16 collective energy operators between 2016 and 2019, the production efficiency of operators was estimated using the panel stochastic frontier model. As a result of the estimation, combined steam power operators showed the highest production efficiency and reverse CHP operators showed the lowest efficiency. Furthermore, as a result of examining the factors influencing profitability, it was confirmed that production efficiency has a positive effect on overall profitability. However, businesses with a high proportion of heat production, such as small district electricity operators, profitability was lower. This phenomenon is due to the structural limitations of the current heat sales market. Hence, the adjustment of the heat sales unit price is necessary to improve profitability of collective energy operators.

• Journal of Radiation Protection and Research
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• v.27 no.2
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• pp.77-80
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• 2002

A more practice approach for the determination of monetary values of the unit collective dose for intervention against long-term exposure following a nuclear accident was proposed. In addition, she monetary values of the unit collective dose estimated from the proposed approach were compared with those estimated from the previous model, which are derived from assumptions of routine exposure and the same values are applied in a nuclear accident without modification, using Korean economic data. The monetary values based on the proposed approach showed a distinct difference depending on inequity in the distribution of individual doses. The discounting rate was also an important factor in determination of monetary values of the unit collective dose.

• Management & Information Systems Review
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• v.33 no.4
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• pp.63-75
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• 2014

The paper investigates empirically the determinants of standardization activity at the industry level, focusing on market structure. The enactments or amendments of collective standards is used as the proxy variable for standardization activity. The independent variables, in addition to market structure, are technological opportunity, factor intensity, export ratio, and industry characteristics(assembly). We estimated the logistic regression model(so-called Logit), using the pooling data for 9 Korean industries, including foods, textiles, chemicals, nonmetallic minerals, metals, electronics and electrics, machinery, automobiles, and shipbuilding, over 2006-2009. The empirical finding shows that market structure has no any effects on the enactments or amendments of collective standards in Korea. This might infer that oligopolistic firms devote themselves to de facto standards determined by market rather than de jure standards such as collective standards and Korean Standards(KS). Besides market structure variable, whereas technological opportunity and assembly characteristics are likely to relate positively with the enactments or amendments of collective standards, capital intensity and export ratio have no any relationship with industrial standardization, respectively.

• Korean Journal of Legislative Studies
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• v.15 no.1
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• pp.93-118
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• 2009

Why the National Assembly of Korea shows the serious disagreements or arguments in its operation? Regarding the question, this study pays attention to the perceptual differences among the parties for the structure of collective decision-making in the National Assembly of Korea. In addition, this study asserts that deepens the conflicts and the distrust in it. To be more specific, this study discusses about the optimal model for collective decision-making in legislative politics based on Buchanan and Tullock's opinion about it. And then, the trust in legislature forms the basis that makes it possible to respect the will of majority and protect the right of minority. The main reason that can't make the collective decision-making optimally in the National Assembly of Korea is to fight each other without the consensus about it. In this vein, making the collective decision-making optimally and recovering the trust among the parties are necessary to adopt a more consensual system. It will be helpful to prevent the use of noninstitutional means like the outside struggles or physical resistances in the National Assembly of Korea.