• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.1
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• pp.135-140
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• 2020

Recently, due to the rapid diffusion of intelligent systems and IoT technologies, power saving techniques in real-time embedded systems has become important. In this paper, we propose P-GA (Parallel Genetic Algorithm), a scheduling algorithm aims at reducing the power consumption of real-time systems in multi-core hybrid memory environments. P-GA improves the Proportional-Fairness (PF) algorithm devised for multi-core environments by combining the dynamic voltage/frequency scaling of the processor with the nonvolatile memory technologies. Specifically, P-GA applies genetic algorithms for optimizing the voltage and frequency modes of processors and the memory types, thereby minimizing the power consumptions of the task set. Simulation experiments show that the power consumption of P-GA is reduced by 2.85 times compared to the conventional schemes.

• KIISE Transactions on Computing Practices
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• v.23 no.10
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• pp.579-587
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• 2017

Cyber Mission Impact Assessment is one of the essential tasks which many militaries and industrial major companies should perform to effectively achieve their mission. The unexpected damage to an organization's assets results in damage to the whole system's performance of the organizations. In order to minimize the damage, it is necessary to quantify the available capacity of the mission, which can be achieved only with the remaining assets, and to immediately prepare a new second best plan in a moment. We therefore need to estimate the exact cyber attack's impact to the mission when the unwanted damage occurs by modeling the relationship between the assets and the missions. In this paper, we propose a new model which deals with the dependencies between assets and missions for obtaining the exact impact of a cyber attack. The proposed model distinguishes task management from asset management for an efficient process, and it is implemented to be optimized using a vectorized operation for parallel processing and using a buffer to reduce the computation time.

• KIISE Transactions on Computing Practices
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• v.23 no.8
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• pp.498-503
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• 2017

SIMD (Single Instruction Multiple Data) is a representative parallelization architecture that processes multiple data loaded in a SIMD register with a single instruction. Quicksort is a sorting algorithm that picks an element as a pivot from the array and reorders the array such that all elements having the values less than the pivot value are located in the left side on the pivot as well as all elements having the value greater than the pivot value are located in the right side on the pivot and then the algorithm performs the same task on both sublist recursively. In this paper, we propose an efficient Quicksort algorithm applying the SIMD instructions which minimally invokes conditional branches to avoid the performance degradation incurred by branch misprediction in a pipeline architecture. In addition, we improve the performance of the Quicksort algorithm by fetching data into a SIMD register as a byte unit to apply VBP (Vertical Bit Parallel) and the early pruning technique.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.1
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• pp.173-183
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• 2018

It is a very difficult task to establish a collaborative procedure in a new business that requires multilateral collaboration or to revise the regulation by analyzing and proving objectively the problems in the collaborative process conducted already by multilateral collaboration. In this paper, we proposed an optimization model for collaborative process to establish the operation procedure between collaborative parties using PERT/CPM network diagram which allows us to calculate the processing time. In order to verify the effectiveness and usefulness of our model for the collaboration process optimization developed in this study, we applied the developed collaborative procedure to student selection of the work-and-study-in-parallel course associated with a degree executed by Ministry of Employment and Labor. This study can be useful not only for newly establishing or reconfiguring collaborative procedures but also for standardizing the business procedures for building information systems between collaborative organizations.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.1_2
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• pp.1-14
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• 2006

Sort-last parallel rendering using a cluster of GPUs has been widely used as an efficient method for visualizing large- scale volume datasets. The performance of this method is constrained by load balancing when data parallelism is included. In previous works static partitioning could lead to self-balance when only task level parallelism is included. In this paper, we present a load balancing scheme that adapts to the characteristic of volume dataset when data parallelism is also employed. We effectively combine the hierarchical data structures (octree and BSP tree) in order to skip empty regions and distribute workload to corresponding rendering nodes. Moreover, we also exploit a 3D clustering method to determine visibility order and save the AGP bandwidths on each rendering node. Experimental results show that our scheme can achieve significant performance gains compared with traditional static load distribution schemes.

• The KIPS Transactions:PartA
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• v.15A no.2
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• pp.87-94
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• 2008

Message races should be detected for debugging effectively message-passing programs because they can cause non-deterministic executions of a program. Previous tools for detecting message races report that message races occur in every receive operation which is expected to receive any messages. However message races might not occur in the receive operation if each of messages is transmitted through a different logical communication channel so that their incorrect detection makes it a difficult task for programmers to debug programs. In this paper we suggest a tool, MPIRace-Check, which can exactly detect message races by checking the concurrency between send/receive operations, and by inspecting the logical communication channels of the messages. To detect message races, this tool uses the vector timestamp to check if send and receive operations are concurrent during an execution of a program and it also uses the message envelop to inspect if the logical communication channels of transmitted messages are the same. In our experiment, we show that our tool can exactly detect message races with efficiency using MPI_RTED and a benchmark program. By detecting message races exactly, therefore, our tool enables programmers to develop reliable parallel programs reducing the burden of debugging.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.9_10
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• pp.429-440
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• 2008

As embedded system becomes more complex, software development becomes more important in the entire design process. Most embedded applications consist of multi -tasks, that are executed in parallel. So, dataflow model that expresses concurrency naturally is preferred than sequential programming language to develop multitask software. For the execution of multitasking codes, operating system is essential to schedule multi-tasks and to deal with the communication between tasks. But, it is needed to execute multitasking code without as when the target hardware platform cannot execute as or target platforms are candidates of design space exploration, because it is very costly to port as for all candidate platforms of DSE. For this reason, we propose the serialized multitasking code generation technique from dataflow specification. In the proposed technique, a task is specified with dataflow model, and generated as a C code. Code generation consists of two steps: First, a block in a task is generated as a separate function. Second, generated functions are scheduled by a multitasking scheduler that is also generated automatically. To make it easy to write customized scheduler manually, the data structure and information of each task are defined. With the preliminary experiment of DivX player, it is confirmed that the generated code from the proposed framework is efficiently and correctly executed on the target system.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.6-6
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• 2022

Prolonged Russia-Ukraine war, and unstable situation of supply and demand of global crops including the COVID-19 pandemic have raised awareness regarding food crisis, and in addition to this situation, export restriction measures imposed by some countries have accelerated the rise in the prices. Since the Republic of Korea depends annual crop consumption (21.32 million tons) mostly on the imports (food self-sufficiency rate in 2020 was 45.8%, crop self-sufficiency rate was 20.2%), our main task is to stably secure food. Now we need to put focus on building capacity to secure stable food supply, and actively manage and respond to risks. To overcome this condition, the Korean government set robust food sovereignty as its policy task, and has been focusing on the policy capacity by providing financial and policy support in parallel. We need to implement mid- to long-term measures to strengthen food security as well as to ensure domestic price stability. While increasing the domestic capacity to supply food in the mid- to long-term perspective, we are implementing projects to bring in crops which are inevitable to be imported by private companies. Specifically, we are making efforts to expand infrastructure for the public reserve and domestic production of wheat and beans which have low self-sufficiency rate, and to secure food sovereignty by providing support to secure global crop supply chain to private companies. The Ministry of Agriculture, Food and Rural Affairs plans to set a target for food self-sufficiency rate and prepare a policy to strengthen mid- to long-term food security by establishing a task force to strengthen mid- to long-term food security in the Ministry. Especially, although wheat is the second staple food, domestic wheat production and the foundation for the industry is poor. Compared to the wheat imports, domestic production of wheat is 30 thousand tons (self-sufficiency rate of 1%), leading to a vulnerable status against internal and external shocks. Through the establishment of the Wheat Industry Promotion Act (Feb. 2020) and the First Master Plan for Wheat Industry Promotion (Nov. 2020), the Korean government has developed a policy basis, and has been providing financial support in overall across the production, distribution and consumption process. In addition, the government established a production complex for Korean wheat and beans in order to supply affordable government-supplied commodities, provide education and consulting services, and create a high-quality stable production system, including facilities and equipment. We are also continuing to increase the public reserve for wheat and beans with the purpose of stable supply and demand as well as food security. The Korean government will establish and implement mid- to long-term measures to strengthen the foundation for domestic production across production, distribution and consumption process, and to stably secure global supply chain including through diversified import channels.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.01a
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• pp.78-82
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• 2001

Most of current Internet auction systems are simple server programs that partly automated the function of the conventional auction house. These system do not provide sufficient independence, distribution and parallelism between the functions of the conventional auction house. In there are automated by server program, but still users need to execute a repetitive task to monitor the dynamic progress of a certain auction, decide proper bid price, and submit the bid. Another problem is that they support only single as English auction and Dutch auction, but they do not support the double auctions are superior to the single auction with respect to speed., efficiency, and the fair distribution of profit. In this paper, we present design and implement of an agent-based continuous double auction system, called CoDABot, in order to mitigate the limitations of current auctions system. CoDABot supports continuous double auction, provides various bidding agent for users to select, and has been implemented into a multi-agent system that realize more independent, distributed, and parallel subsystems.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.1 s.94
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• pp.211-218
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• 1999

The traditional robot manipulators are actuated by continuous range of motion actuators such as motors or hydraulic cylinders. However, there are many applications of mechanisms and robotic manipulators where only a finite number of locations need to be reached, and the robot’s trajectory is not important as long as it is bounded. Binary manipulator uses actuators which have only two stable states. As a result, binary manipulators have a finite number of states. The number of states of a binary manipulator grows exponentially with the number of actuators. This kind of robot manipulator has some advantage compared to a traditional one. Feedback control is not required, task repeatability can be very high, and finite state actuators are generally inexpensive. And this kind of robot manipulator has a fault tolerant mechanism because of kinematic redundancy. In this paper, we solve the inverse kinematic problem of a binary parallel robot manipulator using neural network and test the validity of this structure using some arbitrary points m the workspace of the robot manipulator. As a result, we can show that the neural network can find the nearest feasible points and corresponding binary states of the joints of the robot manipulator