• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.3
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• pp.581-586
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• 2017

The well-known Integral Pulse Frequency Modulation (IPFM) cardiac oscillator has been used to generate the heart beat fluctuations as a representation of the modulatory autonomic nervous activity in terms of sympathetic and parasympathetic state. The IPFM model produces heartbeats by integrating the modulated sinusoid signals and applying the threshold of unity or chaotic threshold levels. This study aims at evaluating the performance of IPFM model by analyzing the influence of the threshold level with comparatively applying preset threshold of unity and Logistic-map and Henon-map chaotic-threshold. Based on our simulated results with interpreting the spectral features of Heart Rate Variability (HRV), we can conclude that the IPFM model with preset threshold level of unity can generate the optimal heartbeat variations int the sense of clinically valid heartbeats.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.469-472
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• 2003

The computational cost of encryption is a barrier to wider application of a variety of data security protocols. Virtually all research on Elliptic Curve Cryptography(ECC) provides evidence to suggest that ECC can provide a family of encryption algorithms that implementation than do current widely used methods. This efficiency is obtained since ECC allows much shorter key lengths for equivalent levels of security. This paper suggests how improvements in execution of ECC algorithms can be obtained by changing the representation of the elements of the finite field of the ECC algorithm. Specifically, this research compares the time complexity of ECC computation eve. a variety of finite fields with elements expressed in the polynomial basis(PB) and normal basis(NB).

• The Korean Journal of Archival Studies
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• no.10
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• pp.27-62
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• 2004

As the penetration of information technology into everyday life is accelerated day by day, virtually all kinds of human representation of knowledge and arts are produced and distributed in the digital form. It is problematic, however, because digital objects are so volatile that it is not easy to keep them in fixed form. The fatal fragility makes it extremely tricky to preserve the digital heritage of our time for the next generation. The present paper aims to introduce current endeavors made at the international and the national levels and to provide with suggestions for Korean national strategy of digital preservation. It starts with reviewing the global trends of digital archiving and long-term preservation, focusing on standardization, preservation strategies and current experiments and projects being conducted for preserving various digital objects. It then sketches national strategies of several leading countries. Based on the sketch, twofold suggestions for Korean national strategy are proposed: establishing a central coordinating agency and accommodating the digital preservation issue in the legislative and regulatory framework for the information society. The paper concludes with the necessity of cooperation among heritage organizations, including libraries, archives, museums. They should cooperate with each other because they have traditionally been trusted with the custodianship of collective memory of humankind and the digital heritage cannot be passed onto the next generation without their endeavor. They should also work together because any single institution, or any single nation could cover what it takes to complete the task of long-term preservation of our digital heritage.

• Korean Management Science Review
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• v.18 no.1
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• pp.55-68
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• 2001

A virtual shopping mall is like a real-world mall, supports electronic shopping by selling products or services through Interne. Although increasing numbers of products are being marketed on the Web, little efforts has been spent on evaluating what mall is more suitable for marketing electronically and for protecting consumers. Evaluation of virtual shopping malls is regarded as a major task in business-to-consumer electronic commerce. This paper considers the Analytic Hierarchy Process(AHP) method in the evaluation of virtual shopping malls and provides its applications. The AHP is a systematic procedure for representing the elements of any problem, hierarchically. A series of pairwise comparison judgments is performed to express the relative strength or intensity of impact of the elements in the hierarchy. The AHP model hierarchy consists of the four following levels: decision maker, main criteria, sub-criteria, and virtual shopping malls. the main criteria include the state of physical firms, representation of information on the virtual shopping malls, product or service, convenience for shopping, consumer protection, and consumer service. The total number of sub-criteria in the third level is twenty-nine. All decision makers selected belong to virtual shopping mall enterprises, or universities. As a case study, we show the synthesized priority of the five virtual shopping malls that have acquired an E-Trust mark. Finally a sensitivity analysis shows how well each virtual shopping mall performs on each criterion by increasing or decreasing the importance of the main criteria.

• The Korean Journal of Health Service Management
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• v.5 no.2
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• pp.187-197
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• 2011

The purpose of this study is to analyze factors related to the job stress experienced by call center employees at public institutions, so as to provide basic data to relieve work-related stress and enhance the job satisfaction of such employees. To promote objectivity and representation, the study was conducted by way of survey, the subjects being call center employees in 8 public institutions that operate call centers, which are located in the Busan and Seoul areas. Of the 240 surveys distributed, 196 were collected and 173 of those were used for analysis after eliminating 25 with insufficient responses. The results of this study are as follows. First, in terms of general properties, it was determined that employees with higher levels of education and families to support had greater job stress. second, in terms of job-related properties, employees who were unsatisfied with the job, HR policies, and their relationship with superiors and/or colleagues had greater job stress. In terms of the group that was satisfied compared with the group that was unsatisfied with the job, HR policies, and their relationship with superiors and/or colleagues, regular workers had less job stress than irregular workers.

• The Journal of Korean Association of Computer Education
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• v.18 no.5
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• pp.25-34
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• 2015

The purpose of this research is to suggest the method of code analysis for evaluating learners' projects in computational thinking(CT) education. Recently, block programming tools are applied to K-12 SW education, this study considered the assessment method for evaluating students' levels and learning about CT concepts through analyzing codes of the Scratch projects that students created. As a result from the analysis of 45 projects of novices, it showed the bad coding patterns of novices and verified that it is possible to evaluate students' learning about CT concepts through the analysis of their codes. The higher learner's level, the greater scores of logical thinking, synchronization, flow control, and data representation. This result is able to apply to student assessment of CT concepts in K-12 SW education.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.11
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• pp.169-178
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• 2021

Motivating employee work engagement, which has emerged as one of the most significant drivers of high performance and achievement in today's dynamic environment, has become essential in gaining a sustainable competitive advantage. As widely known, leadership is a primary factor affecting work engagement. This is also directly related to a specific style of leadership exercised. Leadership styles affect the work engagement levels of the employees. The distracting nature of leadership type can have adverse impacts on individuals' behaviors. To provide a comprehensive understanding of the phenomenon, this article draws on social interaction theory and social exchange theory to investigate the potential effects of inclusive leadership on work engagement within the workplace, and the mediating role of psychological safety on the relationship between inclusive leadership and the work engagement. Here, psychological safety is needed by employees to avoid and manage negative feelings. SPSS and AMOS software was applied to survey data obtained from (n = 373) employees. Results revealed that inclusive leadership is a strong predictor for work engagement, and psychological safety partially mediates the link between inclusive leadership and work engagement. Implications for theory and practice alongside limitations are discussed.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.5 no.1
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• pp.19-24
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• 1993

With the use of Supercomputer and engineering workstations, high quality computer graphic representation of the modeling of marine process is feasible. In this wort major tsunami events occurred during recent years were simulated by numerical models and the computed water levels were viewed as three-dimensional surfaces in an animated sequence. Photorealistic images are constructed by advanced rendering technique with light reflection and shadows. It has demonstrated that video animation of numerical results reproduced the behaviour of propagation of real tsunami events remarkably well.

• Science of Emotion and Sensibility
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• v.5 no.1
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• pp.79-90
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• 2002

The role of memory is viewed as central to developing and maintaining flight situation awareness (SA). The present research examines constituent memory processes that underlie flight SA sensitivity as a function of pilot expertise. In Experiment 1, pilot memory for different forms (spatial or verbal) of cockpit situational information was tested immediately after presentation of the information (immediate recall) or after 30-s delay filled with an intervening task (delayed recall). In Experiment 2, pilot SA sensitivity was examined and correlated with memory measures obtained in Experiment 1. Results suggest that an expertise effect occurs in delayed recall but not in immediate recall and that memory representation of situational information required to develop high levels of SA sensitivity varies as a function of expertise. Theoretical accounts of results are discussed in the context of psychological theories of expertise.

• Journal of Ocean Engineering and Technology
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• v.22 no.3
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• pp.18-23
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• 2008

This study investigated interactions between the internal-external wave field of a permeable coastal structure consisting of rubble. The study examined the application criteria of an existing numerical model (CADMAS-SURF V.4.0) and proposed a modified method to provide reasonable results. In particular, the study focused on and emphasized the water surface profiles in front of a structure, wave run-up/run-down on a slope, and internal water level fluctuations due to the drag coefficient and porosity of a rubble mound structure. In conclusion, the result show that when the vertical fluctuations of the internal water levels in permeable coastal structures exhibited high-quality representation. Sane responses can be seen for wave run-up/run-down characteristics on its slopes.