• Journal of Information Processing Systems
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• 제17권5호
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• pp.905-917
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• 2021

In recent years, edge computing technology consists of several Internet of Things (IoT) devices with embedded sensors that have improved significantly for monitoring, detection, and management in an environment where big data is commercialized. The main focus of edge computing is data optimization or task offloading due to data and task-intensive application development. However, existing offloading approaches do not consider correlations and associations between data and tasks involving edge computing. The extent of collaborative offloading segmented without considering the interaction between data and task can lead to data loss and delays when moving from edge to edge. This article proposes a range segmentation of dynamic offloading (RSDO) algorithm that isolates the offload range and collaborative edge node around the edge node function to address the offloading issue.The RSDO algorithm groups highly correlated data and tasks according to the cause of the overload and dynamically distributes offloading ranges according to the state of cooperating nodes. The segmentation improves the overall performance of edge nodes, balances edge computing, and solves data loss and average latency.

• 대한통합의학회지
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• 제7권3호
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• pp.117-125
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• 2019

Purpose : The purpose of this study was to determine the effects of simultaneous application of focal vibration stimulation and task-oriented training on the improvement in upper extremity motor function after stroke. Methods : The study period was from January to April 2019; 23 patients who fulfilled the study eligibility criteria were enrolled. The participants were divided into two groups: the experimental group with vibration stimulation and task-oriented training and the control group with only task-oriented training. Training was conducted in a total of 20 sessions, 5 times a week for 30 minutes a day for 4 weeks. The amount of use of the affected and unaffected side by accelerometers, and Box and Block test (BBT), Action Research Arm Test (ARAT) was measured with a pre-test, a post-test. Wilcoxon Signed Rank Test and Analysis of Covariance were used to compare and analyze the changes within and between the groups. Results : Both the groups showed statistically significant changes in the results of the BBT and the ARAT, as well as the amount of use of the affected and unaffected side. Regarding the use of the affected side, BBT results, and the grasp and gross movement item of the ARAT showed significant changes in the experimental group compared with the control group. Conclusion : We found that simultaneous application of focal vibration stimulation and task-oriented training was more effective than task-oriented training alone. A large-scale comparative study involving a group that is only given vibration stimulation should be conducted for more generalizable results.

• 한국안전학회지
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• 제21권5호
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• pp.103-111
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• 2006

The purpose of this study was to analyse the relationships between cognitive abilities and driving characteristics of elderly drivers. Driving characteristics of elderly and younger drivers who were driving a fixed base driving simulator vehicle were examined. Participants consisted of 12 drivers over age 65 (the 'older' group) and 12 drivers between the ages of 25 and 55 (the "younger" group). As indices of cognitive ability, critical flicker fusion frequency (CFF) tests and cognitive reaction tests were given before the driving task. CFF was also tested after the simulated driving task for both groups. Cognitive reaction tests, which were composed of speed estimation tests, multiple choice reaction tests and obstacle avoidance tests, were developed by the Korean Road Traffic Safety Authority in 2003. CFF values between the two groups exhibited significant differences both before and after the task, with a p-value less than 0.01 and a t-value of -3.01 before the test and a p-value less than 0.031 and a t-value of -2.35 after the test. Older drivers' CFF values were lower than those of the younger. However, there was no difference in older or younger driver CFF values before and after the task within the same group. Except for the multiple choice reaction test, there was no difference in cognitive reaction test results between the two groups. The elderly drivers made more errors though they did not differ from the younger drivers in reaction times. At the simulated driving task the reaction time of the elderly driver was longer than that of the younger; however, the driving speed of the elderly was lower and the number of collisions greater. There was a positive correlation (r=.496) between the number of errors in the multiple choice reaction test and the number of collisions in the driving task. Therefore, it was identified that critical attributes contributing to automobile crashes involving elderly drivers included cognitive difficulty in judging and responding to complex situations.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1997년도 추계학술대회논문집
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• pp.437-440
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• 1997

The association of poor body postures with pains or symptoms of musculoskeletal discorders has been reported by many researchers. An ergonomic evaluation of postural stresses as well as biomechanical stresses is also important especially when a job involves highly repetitive or prolonged poor body postures. The human body is divided into five parts: shoulder/upper arm, lower arm/wrist, back, neck, lower extremities. A work-sampling based macropostural classification system was developed to characterize various postures in this study. Application of the posture classification schema developed in this study to 7 automobile assembly tasks showed that the schema can be used as a tool to didntify the operation and tasks involving highly stressful body postures. This posture classification schema can also be applied as a basis for quantitive evaluating the workload of manual task.

• 한국멀티미디어학회논문지
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• 제7권5호
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• pp.755-765
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• 2004

최근에 많은 유휴 상태의 호스트 자원들을 이용한 인터넷 기반 분산/병렬 컴퓨팅은 대용량 작업처리와 여러 중요 논제들에 대해 그 유용성이 증명되고 있다. 대용량 작업이 수행되는 동안, 작업에 참여하는 호스트의 성능과 상태 변화에 대처하기 위한 실시간 모니터링 기능이 요구된다. 본 연구에서는 글로벌 컴퓨팅 (global computing) 인트라스트럭처(infrastructure)로 구축된 인터넷 기반 분산/병렬 처리 프레임워크인 PDP(Parallel Distributed Processing)상의 실시간 모니터링 및 시각화에 대한 내용을 소개한다.

• International Journal of Computer Science & Network Security
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• 제22권4호
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• pp.310-328
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• 2022

Internet of things (IoT) has emerged as the most popular technique that facilitates enhancing humans' quality of life. However, most time sensitive IoT applications require quick response time. So, processing these IoT applications in cloud servers may not be effective. Therefore, fog computing has emerged as a promising solution that addresses the problem of managing large data bandwidth requirements of devices and quick response time. This technology has resulted in processing a large amount of data near the data source compared to the cloud. However, efficient management of computing resources involving balancing workload, allocating resources, provisioning resources, and scheduling tasks is one primary consideration for effective computing-based solutions, specifically for time-sensitive applications. This paper provides a comprehensive review of the source management strategies considering resource limitations, heterogeneity, unpredicted traffic in the fog computing environment. It presents recent developments in the resource management field of the fog computing environment. It also presents significant management issues such as resource allocation, resource provisioning, resource scheduling, task offloading, etc. Related studies are compared indifferent mentions to provide promising directions of future research by fellow researchers in the field.

• International Journal of Control, Automation, and Systems
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• 제6권6호
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• pp.904-914
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• 2008

An action-selection-mechanism(ASM) has been proposed to work as a fully connected finite state machine to deal with sequential behaviors as well as to allow a state in the task program to migrate to any state in the task, in which a primitive node in association with a state and its transitional conditions can be easily inserted/deleted. Also, such a primitive node can be learned by a shortest path-finding-based reinforcement learning technique. Specifically, we define a behavioral motivation as having state-dependent value as a primitive node for action selection, and then sequentially construct a network of behavioral motivations in such a way that the value of a parent node is allowed to flow into a child node by a releasing mechanism. A vertical path in a network represents a behavioral sequence. Here, such a tree for our proposed ASM can be newly generated and/or updated whenever a new behavior sequence is learned. To show the validity of our proposed ASM, experimental results of a mobile robot performing the task of pushing- a- box-in to- a-goal(PBIG) will be illustrated.

• Journal of applied mathematics & informatics
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• 제8권3호
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• pp.829-840
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• 2001

Generally it is not easy task whether the stable systems governed by nonlinear ordinary differential equations are asymptotically stable or not. This problem often appears in studying a collision and avoidance control problem based on the stability theory. In this paper we devoted to finding conditions that the stable system obtained from the collision and avoidance control problem is asymptotically stable.

• 한국초등수학교육학회지
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• 제16권2호
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• pp.253-267
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• 2012

본 연구는 창의성이 발현되는 인지적 과정이 무엇인지에 대한 관점을 이론적으로 고찰한 후, 이를 토대로 수학적 창의성을 계발하고 측정하는데 바람직한 과제와 수업 방향을 제시하는 것을 목적으로 한다. 먼저, 창의성에 대한 영역-특수적 관점과 영역-일반적 관점을 이론적으로 고찰하였다. 창의성 발현에 대한 이 두 관점은 이론적 논의에 그치지 않고 수학적 창의성을 계발하고 신장시키기 위해 고안된 과제와 프로그램에 영향을 미친다. 창의성에 대한 교육학적 고찰에서는 수학적 창의성을 검사하고 계발하기 위한 과제와 수업 프로그램이 구비해야할 조건을 이론적으로 탐색한 후, 이를 바탕으로 실제 수학 수업에서 활용가능한 과제와 수업 사례를 제시하였다. 이 연구의 핵심적인 결론은 창의성의 발현되는 과정에 대한 연구는 수학적 창의성 연구의 핵심이 되어야 하며, 아울러 확산적 사고는 수학적 창의성 계발을 위한 필요조건이지만 충분조건은 될 수 없으므로, 수학적 창의성을 계발하기 위해서는 일반화, 추상화 등 다양한 수학적 추론과 수학적 지식을 고려할 필요가 있다.

• 한국과학교육학회지
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• 제22권2호
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• pp.314-335
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• 2002

The purpose of this study was to investigate the effects of students' prior knowledge on scientific reasoning process performing a task of controlling variables with computer simulation and to identify a number of problems that students encounter in scientific discovery. Subjects for this study included 60 Korean students: 27 fifth-grade students from an elementary school; 33 seventh-grade students from a middle school. The sinking objects task involving multivariable causal inference was used. The task was presented as computer simulation. The fifth and seventh-grade students participated individually. A subject was interviewed individually while the investigating a scientific reasoning task. Interviews were videotaped for subsequent analysis. The results of this study indicated that students' prior knowledge had a strong effect on students' experimental intent; the majority of participants focused largely on demonstrating their prior knowledge or their current hypothesis. In addition, studnets' theories that were part of one's prior knowledge had significant impact on formulating hypotheses, testing hypothesis, evaluating evidence, and revising hypothesis. This study suggested that students' performance was characterized by tendencies to generate uninformative experiments, to make conclusion based on inconclusive or insufficient evidence, to ignore, reject, or reinterpret data inconsistent with their prior knowledge, to focus on causal factors and ignore noncausal factors, to have difficulty disconfirming prior knowledge, to have confirmation bias and inference bias (anchoring bias).