• Journal of the Korea Society of Computer and Information
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• v.26 no.9
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• pp.213-221
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• 2021

In this study, an simulation app was developed as one of the methods to help learners better understand the eight process scheduling policies of multi-programming. In learning, an app in the form of a simulation should provide a realistic environment and allow learners to practice. To do this, the needs of the learners were investigated and analyzed, and the purpose was set, designed, and programmed based on the learners' understanding. And it was shown that the apps as a tool to simulate the created eight scheduling policies are performing well. In particular, it was shown that the problem of not having a step-by-step various diagram and explanation for step-by-step various inputs, which is a limitation of paper textbooks, can be solved using these tools.

• Journal of the Korea Society of Computer and Information
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• v.25 no.9
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• pp.193-201
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• 2020

In this study, we developed a simulation app that performs the Test-and-Set algorithm. The test-and-set algorithm is a highly difficult algorithm, so this simulation app was created for learners who have difficulty understanding it. Learners who want to understand the Test-and-Set algorithm gather to form a team, and use this simulation app to discuss and practice, and these teams can practice at the same time. The test-and-set, which is assumed to be a machine language, is not interrupted by using a queue, and it can be seen that the configured simulation app performs well in all three conditions of 'mutual exclusion', 'progress', and 'bounded waiting' that must be solved in the critical area problem.

• Molecules and Cells
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• v.27 no.6
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• pp.651-656
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• 2009

The formation of ${\beta}$-amyloid peptide ($A{\beta}$) is initiated from cleavage of amyloid precursor protein (APP) by a family of protease, ${\alpha}$-, ${\beta}$-, and ${\gamma}$-secretase. Sub W, a substrate peptide, consists of 10 amino acids, which are adjacent to the ${\beta}$-cleavage site of wild-type APP, and Sub M is Swedish mutant with double mutations on the left side of the ${\beta}$-cleavage site of APP. Sub W is a normal product of the metabolism of APP in the secretary pathway. Sub M is known to increase the efficiency of ${\beta}$-secretase activity, resulting in a more specific binding model compared to Sub W. Three-dimensional structures of Sub W and Sub M were studied by CD and NMR spectroscopy in water solution. On the basis of these structures, interaction models of ${\beta}$-secretase and substrate peptides were determined by molecular dynamics simulation. Four hydrogen bonds and one water-mediated interaction were formed in the docking models. In particular, the hydrogen bonding network of Sub M-BACE formed spread over the broad region of the active site of ${\beta}$-secretase (P5-P3'), and the side chain of P2- Asn formed a hydrogen bond specifically with the side chain of Arg235. These are more favorable to the cleavage of Sub M by ${\beta}$-secretase than Sub W. The two substrate peptides showed different tendency to bind to ${\beta}$-secretase and this information may useful for drug development to treat and prevent Alzheimer's disease.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.635-637
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• 2016

The purpose of this study was to apply other programming tools such as robots parish. The robot was utilized for Lego Mindstorms NXT. Programming tools were used to block generic programming tools were used in the NXT-G, was used as a simulation programming tools MSRDS, mobile App Inventor is a programming tool (App Inventor). It can lead to interesting effects of learning and learning based on three programming tool above.

• Journal of Information Technology Services
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• v.19 no.6
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• pp.161-175
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• 2020

The current study aimed to develop the design principles for maker programs using virtual reality and apply them in developing a simulation mobile application. First, through collecting and analyzing the relevant studies and cases eight design principles with four components were derived. Then, these initial design components and principles were revised and improved in accordance with evaluations of an expert panel composed of three professors/researchers, two teachers, and two IT industrial experts. Based on the revised design principles, a VR simulation app for maker education was developed and evaluated on whether the principles were properly applied to the app development by the expert panel. The finalized eight design principles, as a research outcome, can contribute to the design and development of various types of educational programs that can replace the actual making experience even in educational fields where it is difficult to build maker spaces or provide materials and equipment. In the near future, empirical studies are expected to develop customized maker programs considering the characteristics, levels, and needs of students and verify their educational effectiveness.

• Journal of Communications and Networks
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• v.10 no.1
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• pp.44-54
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• 2008

In this paper, an iterative multiple symbol differential detection for turbo coded differential unitary space-time modulation using a posteriori probability (APP) demodulator is investigated. Two approaches of different complexity based on linear prediction are presented to utilize the temporal correlation of fading for the APP demodulator. The first approach intends to take account of all possible previous symbols for linear prediction, thus requiring an increase of the number of trellis states of the APP demodulator. In contrast, the second approach applies Viterbi algorithm to assist the APP demodulator in estimating the previous symbols, hence allowing much reduced decoding complexity. These two approaches are found to provide a trade-off between performance and complexity. It is shown through simulation that both approaches can offer significant BER performance improvement over the conventional differential detection under both correlated slow and fast Rayleigh flat-fading channels. In addition, when comparing the first approach to a modified bit-interleaved turbo coded differential space-time modulation counterpart of comparable decoding complexity, the proposed decoding structure can offer performance gain over 3 dB at BER of $10^{-5}$.

• The Journal of Korean Institute of Information Technology
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• v.17 no.4
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• pp.87-97
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• 2019

SRS was proposed for immediate processing of the meaning of sensor data on mobile devices independent from specific sensor networks and sensor type. However, each time new sensor data is received, sensor data inspection operations are performed repeatedly, and it cause resulting in low performance. App profile-based SRS has been proposed to resolve the problem. The app profile-based SRS has improved the SRS problem through the profile, but has been tested in a virtual simulation environment. After that the test was experimented in a real-time environment, but has not been tested with a variety of dynamic factors. Therefore, this paper experiment considering such as user mobility and sensor density in real-time environment. And this paper also evaluate performance of the App profile-based through analysis of the results of the experiment. As a result, app profile-based SRS is high influence by density and sensor type, and the number of sensor node is not influence.

• Journal of Korea Game Society
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• v.11 no.6
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• pp.139-148
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• 2011

Various types of games have been published in a smart phone game market. However, there are little serious simulation games among them. In this study, parking simulation game has been developed and published on the Apple app store and Android market, to analyze the usability and prospects of the smart phone based serious simulation game. Developed game was designed to give users realistic simulation experience with immersion in the smart phone environment. In case of Apple app store, more than 300 thousands download have been recorded. This means serious simulation games have much more potential for commercial value, even though there are constrains with small display and user interface.

• Computers and Concrete
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• v.13 no.2
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• pp.187-207
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• 2014

This paper mainly discusses the influence of the aggregate properties including grading, shape, content and distribution on the chloride diffusion coefficient, as well as the initiation time of steel corrosion from a probabilistic point of view. Towards this goal, a simulation method of random aggregate structure (RAS) based on elliptical particles and a procedure of finite element analysis (FEA) at meso-scale are firstly developed to perform the analysis. Next, the chloride diffusion coefficient ratio between concrete and cement paste $D_{app}/D_{cp}$ is chosen as the index to represent the effect of aggregates on the chloride diffusion process. Identification of the random distribution of this index demonstrates that it can be viewed as actually having a normal distribution. After that, the effect of aggregates on $D_{app}/D_{cp}$ is comprehensively studied, showing that the appropriate properties of aggregates should be decided by both of the average and the deviation of $D_{app}/D_{cp}$. Finally, a case study is conducted to demonstrate the application of this mesoscopic method in predicting the initiation time of steel corrosion in reinforced concrete (RC) structures. The mesoscopic probabilistic method developed in this paper can not only provide more reliable evidences on the proper grading and shape of aggregates, but also play an important role in the probability-based design method.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.5
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• pp.135-142
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• 2013

With a rapid growth of hardware and product material industries, evolution of handheld terminal technologies is progressed. Various applications using mobile phone are the major trend in recent smart applications. Especially, interesting applications using camera module in a smartphone are developed continuously, mobile users are able to use various useful mobile applications nowadays. In this paper, we design and implement smartphone app for measuring real size of the shooting object in the image taken by a camera module in a smartphone precisely. We implement 4 different shooting modes for precise measurement of objects and 0 point control module is developed to minimize the differences of shooting images taken by different types and systems of various smartphones. The smartphone app proposed and implemented in this paper is analyzed and evaluated by a simulation study.