• Journal of the Korea Society of Computer and Information
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• v.24 no.11
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• pp.11-19
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• 2019

Recently, hybrid CDN/P2P video streaming architecture is specially designed and deployed to achieve the scalability of P2P networks and the desired low delay and high throughput of CDNs. In this paper, we propose a cooperative video streaming and active node buffer management technique in hybrid CDN/P2P architecture. The key idea of this streaming strategy is to minimize network latency such as jitter and packet loss and to maximize the QoS(quality of service) by effectively and efficiently utilizing the information sharing of file location in CDN's proxy server which is an end node located close to a user and P2P network. Through simulation, we show that the proposed cooperative video streaming and active node buffer management technique based on CDN and P2P network improves the performance of realtime video streaming compared to previous methods.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1286-1294
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• 2011

This paper reviews the future directions and perspectives on the soil environmental researches in the 21 century. Previously, the principal emphasis of soil environmental researches had put on the enhancement of food and fiber productions. Beside the basic function of soil, however, the societal needs on soil resources in the 21st century have demands for several environmental and social challenges, occurring regionally or globally. Typical global issues with which soil science should deal include food security with increasing agronomic production to meet the exploding world population growth, adaptation and mitigation of climate change, increase of the carbon sequestration, supply of the biomass and bioenergy, securing the water resource and quality, protection of environmental pollution, enhancing the biodiversity and ecosystem health, and developing the sustainable farming/cropping system that improve the use efficiency of water and agricultural resources. These challenges can be solved through the sustainable crop production intensification (SCPI) or plant welfare concept in which soil plays a key role in solving the abovementioned global issues. Through implementation of either concept, soil science can fulfill the goal of the modern agriculture which is the sustainable production of crops while maintaining or enhancing the ecosystem function, quality and health. Therefore, directions of the future soil environmental researches should lie on valuing soil as an ecosystem services, translating research across both temporal and spatial scales, sharing and using data already available for other purposes, incorporating existing and new technologies from other disciplines, collaborating across discipline, and translating soil research into information for stakeholders and end users. Through the outcomes of these approaches, soil can enhance the productivity from the same confined land, increase profitability, conserve natural resource, reduce the negative impact on environment, enhance human nutrition and health, and enhance natural capital and the flow of ecosystem services. Soil is the central dogma, final frontier and new engine for the era of sustainability development in the $21^{st}$ century and thus soil environmental researches should be carried according to this main theme.

• Korean Medical Education Review
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• v.23 no.3
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• pp.160-167
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• 2021

Rapid developments in technology as part of the Fourth Industrial Revolution have created a demand for educational technology (EdTech) and a gradual transition from traditional teaching and learning to EdTech-assisted learning in medical education. EdTech is a portmanteau (blended word) combining the concepts of education and technology, and it refers to various attempts to solve education-related problems through information and communication technology. The aim of this study was to explore the use of key EdTech applications in medical education programs. A scoping review was conducted by searching three databases (PubMed, CINAHL, and Educational Sources) for articles published from 2000 to June 2021. Twenty-one studies were found that presented relevant descriptions of the effectiveness of EdTech in medical education programs. Studies on the application and effectiveness of EdTech were categorized as follows: (1) artificial intelligence with learner-adaptive evaluation and feedback, (2) augmented/virtual reality for improving learning participation and academic achievement through immersive learning, and (3) social media/social networking services with learner-directed knowledge generation, sharing, and dissemination in medical communities. Although this review reports the effectiveness of EdTech in various medical education programs, the number of studies and the validity of the identified research designs are insufficient to confirm the educational effects of EdTech. Future studies should utilize suitable research designs and examine the instructional objectives achievable by EdTech-based applications to strengthen the evidence base supporting the application of EdTech by medical educators and institutions.

• Journal of Convergence for Information Technology
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• v.9 no.2
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• pp.100-107
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• 2019

The purpose of this study is to develop an evaluation model to measure the core competences of actual play workers by exploring what competences are necessary for them to provide quality play. Based on literature review, we selected five core competences : knowledge of play, program development, understanding play culture, creativity, and information sharing & applying. In order to achieve the research purpose end, a two-round Delphi survey was conducted on 10 play and education experts. The findings drew scholarly consensus on the competences of play workers to have and proposed basic data by developing competences evaluation model to measure them. Each of the key competences has three sub-conpetences, each of which included two behavior elements. Furthermore, this study presented future research directions so that play can be voluntarily planned and supported in a social and cultural context.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.4
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• pp.719-728
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• 2019

Recently, there has been a growing market for shared mobility businesses that share 'transport' such as cars and bikes, and many operators offer a variety of services. However, if the fare can not be charged normally because of security vulnerability, the operator can not continue the business. So there should be no security loopholes. However, there is a lack of awareness and research on shared mobility security. In this paper, we analyzed security vulnerabilities exposed in application log of shared bike service in Korea. We could easily obtain the password of the bike lock and the encryption key of the AES-128 algorithm through the log, and confirmed the data generation process for unlocking using software reverse engineering. It is shown that the service can be used without charge with a success rate of 100%. This implies that the importance of security in shared mobility business and new security measures are needed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.589-592
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• 2016

The period of the previous multi-core could be helped to improve program performance, based on the development of the hardware. However, one of the core performance enhancements for this encounter limitations and become the common way of multi-core with multiple cores. Modern programming concurrency that improves the conventional method for using threads of the kernel level in order to use the multi-core come to the fore. Using modern lightweight thread concurrency programming is to optimize the benefits of multi-core. Also sharing the absence of available data that can change is a major consideration when writing concurrent code. This paper describes the key considerations when creating a discussion concurrent code, and these issues are being supported in any way in the language of one 'go' of technologies that support the modern concurrency, and even how to write better code concurrency.

• Journal of IKEEE
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• v.23 no.2
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• pp.388-394
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• 2019

This paper describes a design of security system-on-chip (SoC) that integrates a Cortex-M0 CPU with an AAW (ARIA-AES- Whirlpool) crypto-core which implements two block cipher algorithms of ARIA and AES and a hash function Whirlpool into an unified hardware architecture. The AAW crypto-core was implemented in a small area through hardware sharing based on algorithmic characteristics of ARIA, AES and Whirlpool, and it supports key sizes of 128-bit and 256-bit. The designed security SoC was implemented on FPGA device and verified by hardware-software co-operation. The AAW crypto-core occupied 5,911 slices, and the AHB_Slave including the AAW crypto-core was implemented with 6,366 slices. The maximum clock frequency of the AHB_Slave was estimated at 36 MHz, the estimated throughputs of the ARIA-128 and the AES-128 was 83 Mbps and 78 Mbps respectively, and the throughput of the Whirlpool hash function of 512-bit block was 156 Mbps.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.3
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• pp.61-69
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• 2019

The concept of carsharing involves sharing a small number of reserved cars to be used individually by a larger number of people as required. This study examines the operating parameters of one-way carsharing systems in order to determine the appropriate operating conditions that minimizes the lost sales rate. Five operating parameters are tested in this study: the number of stations, the average number of vehicles per station, the rate of one-way trip, the average number of staffs per station, and the relocation policy. The performance of round-trip carsharing systems is also compared to that of one-way carsharing systems. A simulation model is developed and simulations are performed to determine the appropriate combination of operating parameter and levels. The simulation results show that the average number of vehicles per station is the most critical parameter. Other key findings obtained from this research are as follows. First, applying the appropriate relocation policy to one-way carsharing systems can allow more customers to rent vehicles than the traditional round-trip carsharing systems. Second, the appropriate relocation policy should be selected based on the average number of vehicles per station in order to minimize the lost sales rate. Third, the number of stations does not affect the lost sales rate. This study findings will provide tools to understand impact of the carsharing system parameters on the efficiency of the carsharing operations.

• Journal of Digital Convergence
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• v.17 no.8
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• pp.81-88
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• 2019

This study suggests the ways to promote the technology startups founded by professor, who differs from student or researcher in social status, risk-taking tendency, and motivation. Literatures were reviewed to understand the advantage of faculty's tech start-up, foreign cases, and related researches. In addition, key stakeholders were interviewed. The study shows that domestic faculty entrepreneurship is currently in infant stage while facing obstacles in institutional, financial and practical aspects. In order to promote faculty entrepreneurship, the study suggests that university and professor set up the benefit sharing structure in advance, that the public sector establishes a holding company or investment fund dedicated to support a faculty startup, that proactive effort be made to attract passive professors to the startup world, and that private companies join faculty startups in the process of concept proofing and product commercialization. The study is expected to provide government, university, and industry with practical implication in promoting faculty startup.

• Journal of Digital Convergence
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• v.17 no.1
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• pp.91-98
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• 2019

The present study was performed to investigate the general research trends of dyslexia and learning disability to explore the centrality of related variables though analysis of keyword networks. Data were collected from ten years articles research information sharing service(RISS) which is provided by korea education and research information service(KERIS). The research subjects selected for the analysis were keyword cleansing work, extraction major keyword using KrKwic program and using NodeXL program to Visualize the center of connection between keyword. The results of this were as follows. First, totally 72 of keyword were extracted from keyword cleansing process and among those keyword. major keywords included learning disability, dyslexia, RTI. Second, analysis of the betweenness centrality of dyslexia and learing disabilities shows that learning disabilities are a key word that has been addressed in the study of dyslexia and learning disabilities in korea. The results of these studies suggest a method of analyzing trends in qualitative and qualitative analysis in relation to dyslexia and learning disorder.