• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.5
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• pp.875-880
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• 2008

In this paper, a novel method to determine the optimal checkpoint interval for real-time control task is proposed considering its performance degradation according to tasks's execution time. The control task in this paper has a specific sampling period shorter than its deadline. Control performance is degraded as the control task execution time is prolonged across the sampling period and eventually zero when reached to the deadline. A new performance index is defined to represent the performance variation due to the extension of task execution time accompanying rollback fault recovery. The procedure to find the optimal checkpoint interval is addressed and several simulation examples are presented.

• International Journal of Computer Science & Network Security
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• v.22 no.4
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• pp.89-100
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• 2022

With the advancement in the Internet of things Technology (IoT) cloud computing, billions of physical devices have been interconnected for sharing and collecting data in different applications. Despite many advancements, some latency - specific application in the real world is not feasible due to existing constraints of IoT devices and distance between cloud and IoT devices. In order to address issues of latency sensitive applications, fog computing has been developed that involves the availability of computing and storage resources at the edge of the network near the IoT devices. However, fog computing suffers from many limitations such as heterogeneity, storage capabilities, processing capability, memory limitations etc. Therefore, it requires an adequate task scheduling method for utilizing computing resources optimally at the fog layer. This work presents a comprehensive review of different task scheduling methods in fog computing. It analyses different task scheduling methods developed for a fog computing environment in multiple dimensions and compares them to highlight the advantages and disadvantages of methods. Finally, it presents promising research directions for fellow researchers in the fog computing environment.

• Journal of the Korean Dietetic Association
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• v.21 no.1
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• pp.37-56
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• 2015

This study was conducted to develop job standards for clinical dietitian administering clinical nutrition therapy to diabetic patients in hospitals. Based on DACUM (Developing A Curriculum) analysis of 17 members including clinical dietitians, professors majoring in clinical nutrition and researchers, information on duties, tasks and task elements of clinical dietitians for diabetes care were derived and applied to diabetes mellitus-specific clinical nutrition care in hospitals for evaluation. The final developed job standards for clinical dietitians for diabetes care included four duties, 19 tasks and 56 task elements. The duties consisted of nutrition assessment, nutrition diagnosis, nutrition intervention, and nutrition monitoring evaluation. For application of diabetes mellitus-specific job standards in clinical nutrition care, 108 work activities were developed and classified into 90 basic and 18 recommended types. Performance rates of standardized jobs were 80.2% at nutrition assessment, 99.6% at nutrition diagnosis, 78.5% at nutrition intervention, and 32.9% at nutrition monitoring evaluation. These results can be applied as guidelines to implement jobs for diabetes mellitus-specific clinical nutrition services in clinical settings. In addition, they would be useful for education standards in educational institutions for education and training of clinical dietitian.

• Journal of The Korean Society of Integrative Medicine
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• v.5 no.1
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• pp.1-9
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• 2017

Purpose : This study is to examine the effects of different task-related circuit training by types of tasks on the depression and quality of life in stroke patients. Method : Forty-four chronic stroke patients were divided into a dual motor circuit task training group, a dual cognitive circuit task training group and a simple task training group. Over the course of eight weeks, before training, all the patients were identically encouraged to receive conservative physical therapy for 30 minutes, five times a week for a total of eight weeks with individual additional tasks. The dual motor circuit tasks training consisted of continuous circuit training motor tasks and additional motor tasks and the dual cognitive circuit task training consisted of tasks combining the same circuit training motor tasks and additional cognitive tasks. The simple task training consisted of natural walks on a flat terrain to the front, rear and lateral sides of the terrain. Result : As for the Stroke-Specific Quality of Life(SS-QOL) that showed significant diffe rences in comparison between the groups over the training period, the dual motor circuit task training group showed statistically significant differences in both different types of tasks at 8 weeks(p<.05). The score of Hospital Anxiety and Depression Scale(HADS) decreased in three groups, in the HADS showed significant changes over the training time in the three training groups(p<.05). Conclusion : It could be seen that the practical and continuous dual circuit task training was more effective than simple task training on quality of life. In comparison between the types of dual tasks, the dual motor circuit task training group showed more effects than the dual cognitive circuit task training group. This researcher hopes that the results of this study will be actively applied as rehabilitation methods for chronic stroke patients.

• Journal of Industrial Convergence
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• v.8 no.2
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• pp.27-39
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• 2010

After reviewing the existing literature on team coaching, I propose a new model with two distinguishing features. The model (1) focuses on the functions that coaching serves for a team, rather than on either specific leader behaviors or leadership styles, (2) identifies the specific times in the task performance process when coaching inventions are most likely to have their intended effects.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2008.10b
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• pp.479-491
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• 2008

A "task network" is a type of social network that consists of experts who exchange professional help and advice regarding executing tasks. In this study, we investigate the task network used within the IS department of a national bank in Korea. We identify how this network moderates the influence of computer-mediated communication (CMC) technology on an individual s task performance. Size, density, and centrality were measured as the characteristics of a personal task networks. Size equates to the total number of colleagues who work with a specific member for a certain project. Density is the ratio of the number of actual relationships to the total number of available relationships. Centrality defines whether an individual s position is in the exact center of whole network, and is measured by betweenness centrality, meaning the position one member holds between others in a network. Our findings conclude that the conditions - the larger the size of the task network, the smaller its density and the higher its level of centrality - lead to more benefits of using CMC media. Further, this positive effect of CMC is more noticeable when it provides synchronicity.

• The Journal of Korean Academic Society of Nursing Education
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• v.20 no.4
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• pp.577-586
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• 2014

Purpose: This study investigates patterns of small group interaction and examines the influence among graduate nursing students of online collaborative learning strategies on small group interaction patterns, task performance and learning attitude in web-based team learning environments. Method: To analyze patterns of small group interaction, group discussion dialogues were reviewed by two instructors. Groups were divided into two categories depending on the type of feedback given (passive or active). For task performance, evaluation of learning processes and numbers of postings were examined. Learning attitude toward group study and coursework were measured via scales. Results: Explorative interactions were still low among graduate nursing students. Among the students given active feedback, considerable individual variability in interaction frequency was revealed and some students did not show any specific type of interaction pattern. Whether given active or passive feedback, groups exhibited no significant differences in terms of task performance and learning attitude. Also, frequent group interaction was significantly related to greater task performance. Conclusion: Active feedback strategies should be modified to improve task performance and learning attitude among graduate nursing students.

• The KIPS Transactions:PartB
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• v.8B no.6
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• pp.601-608
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• 2001

The automated assignment of multiple tasks to executing agents is a key problem in the area of multi-agent systems. In many domains, significant savings can be achieved by reallocating tasks among agents with different costs for handling tasks. The automation of task reallocation among self-interested agents requires that the individual agents use a common negotiation protocol that prescribes how they have to interact in order to come to an agreement on "who does what". In this paper, we introduce the multi-agent Traveling Salesman Problem(TSP) as an example of task reallocation problem, and suggest the Vickery auction as an interagent negotiation protocol for solving this problem. In general, auction-based protocols show several advantageous features: they are easily implementable, they enforce an efficient assignment process, and they guarantce an agreement even in scenarios in which the agents possess only very little domain-specific Knowledge. Furthermore Vickrey auctions have the additional advantage that each interested agent bids only once and that the dominant strategy is to bid one′s true valuation. In order to apply this market-based protocol into task reallocation among self-interested agents, we define the profit of each agent, the goal of negotiation, tasks to be traded out through auctions, the bidding strategy, and the sequence of auctions. Through several experiments with sample multi-agent TSPs, we show that the task allocation can improve monotonically at each step and then finally an optimal task allocation can be found with this protocol.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.11
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• pp.3638-3657
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• 2022

In urban vehicular edge computing (VEC) environments, one edge server always serves many task requests in its coverage which results in the resource-constrained problem. To resolve the problem and improve system utilization, we first design a general hierarchical resource management framework based on typical VEC network structures. Following the framework, a specific interacting protocol is also designed for our decision algorithm. Secondly, a greedy bidding-based multi-hop task scheduling decision algorithm is proposed to realize effective task scheduling in resource-constrained VEC environments. In this algorithm, the goal of maximizing system utility is modeled as an optimization problem with the constraints of task deadlines and available computing resources. Then, an auction mechanism named greedy bidding is used to match task requests to edge servers in the case of multiple hops to maximize the system utility. Simulation results show that our proposal can maximize the number of tasks served in resource constrained VEC networks and improve the system utility.

• Korean Journal of Construction Engineering and Management
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• v.5 no.2 s.18
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• pp.64-71
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• 2004

A daily report is one of the critical documents in construction projects, since it helps them keep track of various as-built information. Despite the important role in progress management, the daily reporting process is time-consuming, and the representation of task information on daily reports are not effective enough to accumulate daily as-built information for further use in project management. Task information is composed of a specific work type and a location where the task is performed, which means that the same type of work is repeated over the locations. However, in many cases the task locations are described differently depending on a reporter's preference or experience. Without representing task location information effectively, it is difficult to accumulate and to reuse as-built information. The objective of this research is to build a framework for generating task information which can be efficiently accumulated and reused for progress management. To do so, this research built a task information model with focusing on the representation of task location associated with a work type, and developed an information system that supports automated and interactive generation of task information.