• Journal of Advanced Navigation Technology
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• v.13 no.3
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• pp.378-384
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• 2009

In this paper, we consider a cyclostationary-feature-detection based spectrum sensing algorithm for ATSC signal detection. One of the proposed algorithms for IEEE 802.22 standardization organization which meet the requirements of IEEE 802.22 is Thomson's algorithm based on cyclostationary feature detection. We propose an interpolation-based spectrum sensing algorithm for ATSC signal detection, which has less computation complexity than that of Thomson's algorithm and provides no performance loss compared to Thomson's algorithm. By using zero-padding in time domain and effective sensing scanning method, the proposed algorithm requires less computational complexity and shows no performance degradation compared to Thomson's algorithm.

• Journal of Preventive Medicine and Public Health
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• v.37 no.3
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• pp.282-291
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• 2004

Objectives : The aim of this study was to investigate the functional status variables related to the care time of health professionals for patients in long-term care facilities. Methods : The functional stati of 1001 patients in 8 long-term care hospitals were examined by the Resident Assessment Instrument for Long-term Care Facility Version 2.0. The care time of health professionals for patients was calculated using data from a self-reported task survey by nurses, auxiliary nurses, private aides, doctors, physiotherapists and social workers. Results : The average care time per diem was 240.6 minutes. The care time by doctors, nurses and private aides were 11.0, 71.0 and 139.5 minutes, respectively. The lower the function of activities of daily living (ADL) and the greater the symptoms of extensive services, special care and clinical complexity, the more care time was served. On the contrary, the greater the symptoms of nursing rehabilitation, depression, cognitive disorder, behavior problem and psychiatry/mood disorder, the less care time was served. Age and gender were not significantly related to the care time. Conclusions : Developing a case mix classification system for elderly long term care patients may be helpful for both of patients and health care providers. The ADL, extensive services, special care and clinical complexity of variables should be considered in the development of a case mix system for the long term care of patients in Korea.

• Journal of Korea Society of Digital Industry and Information Management
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• v.17 no.1
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• pp.57-73
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• 2021

The purpose of this study is to analyze the diffusion period and productivity of smartwork in an organization. Firms are increasingly interested in smartwork for non contact work and working from home because of the corona 19. The smartwork is a new technology that changes face-to-face work in an organization. It helps the work of individuals and organizations regardless of time and place. The theoretical background describes the complexity, system thinking, diffusion theory, smart work, organizational resistance, and productivity. This study analyzes the diffusion period and productivity of smart work through business simulation techniques. A simulation study progresses four stages. There are problem definition, hypothesis establishment and causal loop diagram, model construction and verification, and policy evaluation. The simulation models contain an individual's resistance variables organizational investment and leadership variables related to the operation of smartwork. The organizational investment variables include organizational culture, legal system, implement systems and technology investment. The individual resistance variables include cognitive, attitude, structure and technological resistance. The leadership includes leadership interest variables and performance linkage variables. The simulation executed the changes of a people number adopting smart work and the organizational productivity monthly. As a result of the simulation, many organization members have accepted the smart work innovation after 20 months. The organizational productivity through smart work showed very high value after 16 months. In scenario analysis, the individuals' awareness and attitude resistance showed very important variables to productivity and a personal change of smart work adoption. Meanwhile, The organizational investment showed that the high driving-force increased not productivity and the low driving-force showed decreased low productivity. Also, leadership variables showed a powerful driver for changing smart work productivity. The implication of the study has suggested extending complexity, diffusion theory and organization resistance theory based on simulation methods.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.4
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• pp.1594-1617
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• 2018

In this paper, we consider a spectrum access scenario which consists of two groups of users, namely Primary Users (PUs) and Secondary Users (SUs) in Cooperative Cognitive Radio Networks (CCRNs). SUs cooperatively relay PUs messages based on Amplify-and-Forward (AF) and Decode-and-Forward (DF) cooperative techniques, in exchange for accessing some of the spectrum for their secondary communications. From the literatures, we found that the Conventional Distributed Algorithm (CDA) and Pragmatic Distributed Algorithm (PDA) aim to maximize the PU sum-rate resulting in a lower sum-rate for the SU. In this contribution, we have investigated a suit of distributed matching algorithms. More specifically, we investigated SU-based CDA (CDA-SU) and SU-based PDA (PDA-SU) that maximize the SU sum-rate. We have also proposed the All User-based PDA (PDA-ALL), for maximizing the sum-rates of both PU and SU groups. A comparative study of CDA, PDA, CDA-SU, PDA-SU and PDA-ALL is conducted, and the strength of each scheme is highlighted. Different schemes may be suitable for different applications. All schemes are investigated under the idealistic scenario involving perfect coding and perfect modulation, as well as under practical scenario involving actual coding and actual modulation. Explicitly, our practical scenario considers the adaptive coded modulation based DF schemes for transmission flexibility and efficiency. More specifically, we have considered the Self-Concatenated Convolutional Code (SECCC), which exhibits low complexity, since it invokes only a single encoder and a single decoder. Furthermore, puncturing has been employed for enhancing the bandwidth efficiency of SECCC. As another enhancement, physical layer security has been applied to our system by introducing a unique Advanced Encryption Standard (AES) based puncturing to our SECCC scheme.

• Korean Journal of Cognitive Science
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• v.28 no.4
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• pp.223-243
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• 2017

A Hangul input method consists of two core components: key layout for primitive units (Natja), and binding rules to form more complex, composite units from primitive ones. However, careless design and implementation of an input method may result in ambiguity and inability of contiguous typing, when it comes to handle composite Hangul units. This is due to the collective nature of Hangul, namely, existence of implicit boundaries between units and syllables. This issue gets more challenging for the context-dependent 2-beolsik method, mobile environment having significantly fewer keys, and yet addition of the support for Old Hangul. For the sake of the management of complexity, we devised a system in which the binding rule is divided into two layers rather than one. Based on this concept, we implemented a tool program that, given the primitive units and their binding rules, generates input details of every composite unit and detects any potential ambiguity and conflicts. We presented the actual analysis result for Samsung Cheonji-in and KT Naratgeul, two of the most popular mobile Hangul input methods used in Korea.

• Korean Journal of Cognitive Science
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• v.12 no.4
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• pp.11-27
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• 2001

Machine translation (MT) quality assessment is an outstanding problem. In the present situation in which the quality of machine-translated products are far from the user\\`s satisfaction objective evaluation of MT system is a prerequisite to building mutual trust between the users and the vendors stimulating constructive competition among the developers and finally leading to improve the quality of MT systems. Especially there emerges a need for an intensive study on how to evaluate the quality of MT systems from both linguistic and data processing aspects and to secure a steady improvement of the translation quality. With due regard to such points we in this paper present a linguistic evaluation of English-to-Korean machine translation based on a test suite composed of 3.373 sentences that were classified into their linguistic phenomena and complexity levels and report the experimental results made from several commercial MT systems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.2
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• pp.520-541
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• 2023

In CRNs, SS is of utmost significance. Every CR user generates a sensing report during the training phase beneath various circumstances, and depending on a collective process, either communicates or remains silent. In the training stage, the fusion centre combines the local judgments made by CR users by a majority vote, and then returns a final conclusion to every CR user. Enough data regarding the environment, including the activity of PU and every CR's response to that activity, is acquired and sensing classes are created during the training stage. Every CR user compares their most recent sensing report to the previous sensing classes during the classification stage, and distance vectors are generated. The posterior probability of every sensing class is derived on the basis of quantitative data, and the sensing report is then classified as either signifying the presence or absence of PU. The ISVM technique is utilized to compute the quantitative variables necessary to compute the posterior probability. Here, the iterations of SVM are tuned by novel GO-PSA by combining GOA and PSO. Novel GO-PSA is developed since it overcomes the problem of computational complexity, returns minimum error, and also saves time when compared with various state-of-the-art algorithms. The dependability of every CR user is taken into consideration as these local choices are then integrated at the fusion centre utilizing an innovative decision combination technique. Depending on the collective choice, the CR users will then communicate or remain silent.

• The Mathematical Education
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• v.62 no.3
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• pp.363-380
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• 2023

This study analyzed the difficulties and mathematical modeling knowledge improvement that an elementary school teacher experienced in modifying a mathematics textbook task to a mathematical modeling task. To this end, an elementary school teacher with 10 years of experience participated in teacher-researcher community's repeated discussions and modified the average task in the data and pattern domain of the 5th grade. The results are as followings. First, in the process of task modification, the teacher had difficulties in reflecting reality, setting the appropriate cognitive level of mathematical modeling tasks, and presenting detailed tasks according to the mathematical modeling process. Second, through repeated task modifications, the teacher was able to develop realistic tasks considering the mathematical content knowledge and students' cognitive level, set the cognitive level of the task by adjusting the complexity and openness of the task, and present detailed tasks through thought experiments on students' task-solving process, which shows that teachers' mathematical modeling knowledge, including the concept of mathematical modeling and the characteristics of the mathematical modeling task, has improved. The findings of this study suggest that, in terms of the mathematical modeling teacher education, it is necessary to provide teachers with opportunities to improve their mathematical modeling task development competency through textbook task modification rather than direct provision of mathematical modeling tasks, experience mathematical modeling theory and practice together, and participate in teacher-researcher communities.

• Journal of the Ergonomics Society of Korea
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• v.26 no.1
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• pp.1-10
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• 2007

As drivers spend more time in their cars, perception of driving a vehicle turns from utilizing a transportation means into residing in a personal space or even in moving office. Such a perception renders automobile manufacturers incorporate more vehicle functions, especially in-vehicle information systems As the number of system functions increases, the complexity of control and 2 types of display menus were designed after a literature review and a market analysis. With these controls and display menus, the experiment was performed to look into the difference of driver performance and preference on the integrated vehicle control type. Finally, the study suggests the integrated vehicle control type to minimize driver's cognitive load, and to use various functions efficiently. The study also discusses the practical use of the final integrated vehicle control type.

• World Technopolis Review
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• v.5 no.2
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• pp.108-118
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• 2016

There are very few studies on governance structure for the collaboration between HEIs and science and technology parks until today. Major activities between science parks and HEIs are R&D activities, collaborative researches, technology transfer, space provision for BIs and Technology BIs in the science parks, provision of technical, legal and financial services for start-ups and venture firms. Governance structure for the collaboration of high education institutes with science and technology parks is the handling of complexity and management of dynamic flows of collaboration between two groups. Three models on the governance structure for the collaboration are suggested in this study. The first model is a governance structure that links R&D system such as universities, public research institutes and private research institutes with industrial production cluster such as a group of companies and industrial parks. The second model is a governance structure that has four layers of hierarchy. This hierarchical governance model is composed of four levels of organizations such as central government, three actors, one center for collaboration and many individual research performers. The third model is a governance structure that networks all the stakeholders horizontally. Under this structure, governance is conducted by the network members with no separate and unique governance entity.