• Journal of KIISE:Computer Systems and Theory
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• v.30 no.7_8
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• pp.359-369
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• 2003

We present efficient generalized algorithms for all-to-all personalized communication operations in a 2D torus. All-to-all personalized communication, or complete exchange, is at the heart of numerous applications, such as matrix transposition, Fast Fourier Transform(FFT), and distributed table lookup. Some algorithms have been Presented when the number of nodes is power-of-2 or multiple-of-four form, but there has been no result for general cases yet. We first present complete exchange algorithm called multiple-Hop-2D when the number of nodes is in the form of multiple-of-two. Then by extending this algorithm, we present two algorithms for an arbitrary number of nodes. Split-and-Merge algorithm first splits the whole network into zones. After each zone performs complete exchange, merge is applied to finish the desired complete exchange. By handling extra steps in Double-Hop-2D algorithm, Modified Double-Hop-2D algorithm performs complete exchange operation for general cases. Finally, we compare the required start-up time for these algorithms.

• The Journal of the Convergence on Culture Technology
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• v.9 no.2
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• pp.307-312
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• 2023

North Korea has already been using underground space for military purposes for decades, and is currently developing it as a key base for operating asymmetric forces. Accordingly, the special operations teams need fighting methods, weapon systems, and organizational structures to carry out subterranean operations. This paper presents an unmanned system platform for subterranean operations that combines tilt-rotor type drones, high-tech sensors, communication repeaters, and small robots, and a system that can be operated by special operation teams. Based on this, the survivability of the special operations teams can be strengthened and operational utility can be maximized. Afterwards, if Special Warfare Command collects collective intelligence based on the ideas related to subterranean operations presented in this paper and further develops these, it will be possible to drive subterranean operations doctrines, weapon systems, and organizational structures optimized for the battlefield on the Korean Theater of Operations in the near future.

• Journal of Communications and Networks
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• v.16 no.4
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• pp.436-446
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• 2014

The high intensity of research and modeling in fields of mathematics, physics, biology and chemistry requires new computing resources. For the big computational complexity of such tasks computing time is large and costly. The most efficient way to increase efficiency is to adopt parallel principles. Purpose of this paper is to present the issue of parallel computing with emphasis on the analysis of parallel systems, the impact of communication delays on their efficiency and on overall execution time. Paper focuses is on finite algorithms for solving systems of linear equations, namely the matrix manipulation (Gauss elimination method, GEM). Algorithms are designed for architectures with shared memory (open multiprocessing, openMP), distributed-memory (message passing interface, MPI) and for their combination (MPI + openMP). The properties of the algorithms were analytically determined and they were experimentally verified. The conclusions are drawn for theory and practice.

• Journal of the FoodService Safety
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• v.2 no.2
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• pp.111-115
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• 2021

The purpose of this study is to evaluate the effectiveness of online and offline blended education for hygiene and safety management of children's foodservice operations in Eunpyeong-gu. For the teachers of the children's foodservice operations, two online sessions and one offline session were conducted with different educational themes each time. In terms of satisfaction with the education, the online program 'Mission Possible' scored 4.8 points and the collective education of teachers and staff scored 4.6 points, indicating that the training composition and communication with the person in charge were high. In other field opinions, it was found that online and offline education according to the situation was very helpful in the overall management of the children's foodservice operations. With fewer face-to-face opportunities, there were difficulties in on-site support and management. To supplement this, various programs were applied to help children's foodservice operations provide healthy and safe meals and snacks.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.3
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• pp.255-263
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• 2000

A multistage interconnection network is a suitable class of interconnection architecture for constructing large-scale multicomputers. Broadcast and multicast communication are fundamental in supporting collective communication operations such as reduction and barrier synchronization. In this paper, we propose a new multicast technique in wormhole-switched bidirectional multistage banyan networks for constructing large-scale multicomputers. To efficiently support broadcast and multicast with simple additional hardware without deadlock, we propose a two-phase multicast algorithm which takes only two transmissions to perform a broadcast and a multicast to an arbitrary number of desired destinations. We encode a header as a cube and adopt the most upper input link first scheme with periodic priority rotation as arbitration mechanism on contented output links. We coalesce the desired destination addresses into multiple number of cubes. And then, we evaluate the performance of the proposed algorithm by simulation. The proposed two-phase multicast algorithm makes a significant improvement in terms of latency. It is noticeable that the two-phase algorithm keeps broadcast latency as efficient as the multicast latency of fanout 2^m where m is the minimum integer satisfying $2^m{\geq} {\sqrt{N}}$ ( N is a network size).

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.5
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• pp.749-756
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• 2011

Recently, ever-growing land price has caused public projects to come to considerable deadlocks. Up to date, project principals have relied upon mandatory expropriation policy or other relevant policies in order to procure land sites required for public projects in a short period, but these policies have brought about collective resistances and civil appeals from land owners and cause land compensation price to rise, resulting in delayed progress of public projects. Therefore, land banking system is enforced to resolve these issues. Successful implementation of land banking system requires purchase of sufficient land sites at affordable price so as to execute public projects and control real estate market. However, current version of Land Banking Act reveals several questions as contrary to public expectations in the days of its introduction. This study sought to make further analysis on the whole content of current legal system concerning land banking system. And based on the analysis, this study explored possible solutions for problems that hinder land banking system from its stable operations, so that this land banking system could contribute to resolving land problems by active promotion of public projects as originally intended and by the stabilization of land market based on balance control between supply and demand of land.

• Journal of KIISE:Software and Applications
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• v.33 no.4
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• pp.378-387
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• 2006

A programming model for ubiquitous sensor network (USN) applications based on Nano-Qplus is proposed. USN applications mean programs of nodes which are components of sensor network such as sensor, router, sink and actuator. Developers can automatically generate programs of USN applications by setting attributes values of nodes using a script after they model a sensor network. A script for setting attributes values of a node is proposed in this paper. The algorithm of automatic code generation is also described. Developers can easily implement USN applications even if they do not know details of low-level communication, data sharing, and collective operations because the applications are automatically generated from a script. They set only attributes values of nodes using the script. Efforts for USN applications development also are reduced because of automatic code generation. Furthermore, developers can correct errors of applications in the early stage of development through ear]y test based on rapid code generation.