• Journal of the Ergonomics Society of Korea
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• v.32 no.5
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• pp.413-420
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• 2013

Objective: The objective of this study was to compare one-hand and two-hands lowering activity in terms of biomechanical stress for the range of lowering heights from knuckle height to 10cm above floor level. Background: Even though two-hands lifting/lowering activity of manual materials handling tasks are prevalent at the industrial site, many manual materials handling tasks which require the worker to perform one-hand lifting/lowering are also very common at the industrial site and forestry and farming. Method: Eight male subjects were asked to perform lowering tasks using both a one-handed as well as a two-handed lowering technique. Trunk muscle electromyographic activity was recorded while the subjects performed the lowering tasks. This information was used as input to an EMG-assisted free-dynamic biomechanical model that predicted spinal loading in three dimensions. Results: It was shown that for the left-hand lowering tasks, the values of moment, lateral shear force, A-P shear force, and compressive force were increased by the average 6%, as the workload was increased twice from 7.5kg to 15kg. For the right-hand lowering task, these were increased by the average 17%. For the two-hands lowering tasks, these were increased by the average 14%. Conclusion: Even though the effect of workload on the biomechanical stress for both one-hand and two-hands lowering tasks is not so significant for the workload less than 15kg, it can be claimed that the biomechanical stress for one-hand lowering is greater than for two-hands lowering tasks. Therefore, it can be concluded that asymmetrical lowering posture would give greater influence on the biomechanical stress than the workload effect for one-hand lowering activity. Application: The result of this study may be used to provide guidelines of recommended safe weights for tasks involved in one-hand lowering activity.

• Journal of dental hygiene science
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• v.20 no.4
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• pp.187-199
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• 2020

Background: Korean dental hygienists perform various tasks under the supervision of dentists in addition to the tasks listed in the law. Many meaningful studies have been conducted to determine the actual tasks of dental hygienists, but these studies did not show common results due to the differences in research methods or designs. Hence, this study aimed to review the reported data on the tasks of dental hygienists in Korea and to clarify them based on a systematic literature review. Methods: For the literature search, the COre, Standard, and Ideal model presented by the National Library of Medicine was referenced. Seven databases were searched for literatures published in Korea, including PubMed, and Google Scholar. Of the 352 studies found using key words, titles, and abstracts, 46 were finally extracted based on the first and second exclusion criteria. After confirming the tasks of Korean dental hygienists in 46 literatures, 136 tasks were listed and calculated as appearance rate in the literature. Results: The most common tasks in 46 studies were fluoride application (67.2%), radiography (65.4%), scaling (65.4%), sealant (60.7%), patient management and counseling (56.7%), tooth-brushing education (52.2%), impression taking with alginate (50.1%), and making temporary crowns (47.9%). The most mentioned tasks of dental hygienists in public health centers were fluoride application (100%), sealant (100%), oral health education (71.4%), public oral health program evaluation (71.4%), school fluoride mouth-rinsing program (71.4%), water fluoridation (57.1%), tooth-brushing education (57.1%), school oral health programs (57.1%), and public elderly oral health programs (57.1%). Conclusion: This study showed that Korean dental hygienists had 136 tasks by reviewing 46 related studies and that the main job of Korean dental hygienists was oral disease prevention including scaling, sealant, and fluoride application.

• Proceedings of the ESK Conference
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• 1998.04a
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• pp.31-35
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• 1998

Many reaearchers have reproted that poor body postures are associated with pains or symptoms of musculoskeletal dissoders. Therefore, the ergonomic evaluation of postural stresses as well as biomechanical stresses is important when a job such as automobile assembly tasks involves highly repetitive and/or prolonged poor body postures. A macropostural classification shema was developed to characterise various body postures occurring in automobile assembly tasks in the study. To specify a postural code and stress level to each body posture, perceived joint discomforts were subjectively evaluated in the lab experiments for the full range of motion in five human body joints. Based on the reaults, a postural classification scheme was developed where the full range of motion in each body joint was classified into several codes repressenting different stress levels. The automobile tasks were clustered into 12 types based on the result walk-in-surveillance and the possible posture codes for each task type are defined. I was exposed that the poor postural problems in automobile assembly tasks were concerned in most part with arms, trunk and neck. Application of te developed schema to seven operations in automobile assembly tasks showed that the schema can be used as a tool to identify the operations and tasks involving highly stressful body postures. The schema can also be utilised as a basis to prioritise the candidate assembly operations for redesign of work methods.

• ETRI Journal
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• v.29 no.3
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• pp.270-280
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• 2007

In Linux, real-time tasks are supported by separating real-time task priorities from non-real-time task priorities. However, this separation of priority ranges may not be effective when real-time tasks make the system calls that are taken care of by the kernel threads. Thus, Linux is considered a soft real-time system. Moreover, kernel threads are configured to have static priorities for throughputs. The static assignment of priorities to kernel threads causes trouble for real-time tasks when real-time tasks require kernel threads to be invoked to handle the system calls because kernel threads do not discriminate between real-time and non-real-time tasks. We present a dynamic kernel thread scheduling mechanism with weighted average priority inheritance protocol (PIP), a variation of the PIP. The scheduling algorithm assigns proper priorities to kernel threads at runtime by monitoring the activities of user-level real-time tasks. Experimental results show that the algorithms can greatly improve the unexpected execution latency of real-time tasks.

• Journal of Educational Research in Mathematics
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• v.27 no.3
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• pp.491-510
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• 2017

This study analyzes on conjecturing tasks in elementary mathematics textbook. We adopted Peircean semiotic perspective and variation theory to analyze conjecturing tasks in elementary mathematics textbook. We specifically analyzed mathematical tasks designed to support students' inquiries into definitions and properties of quardrilaterals. As a result, we found that conjecturing tasks in textbooks do not focus on supporting students' diagrammatic reasoning and inductive verification on provisional abductions. These tasks were mainly designed to support students' conjecturing on commonalities of mathematical objects rather than differences between objects.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.10
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• pp.2277-2282
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• 2010

O(1) time synthetic utilization is not considered periodic tasks, except scheduling methods for aperiodic tasks where one of the aperiodic tasks is a scheduling method. But really aperiodic tasks scheduling method is composed of mixed task types. Aperiodic task scheduling method guarantee an analysis of the schedualibility of aperiodic task. The set of mixed tasks periodic and aperiodic tasks scheduling method uses synthetic utilization that is presented in this paper. The new method shows that schedulability increases 20% aperiodic server method.

• English Language & Literature Teaching
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• v.16 no.4
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• pp.267-290
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• 2010

The purpose of this study is to analyze the writing tasks included in the newly developed high school English textbooks in the aspects of genre, rhetorical structure, task type, and authenticity in order to find out whether these tasks could contribute to improving Korean EFL students' writing skills. A total of nine textbooks were selected for the study and every writing task in each textbook was analyzed. The results show that various types of genres were incorporated in the tasks, but very few opportunities were provided for students to acquire characteristics of specific genres. In terms of rhetorical structure of text, narration, illustration, and transaction were required most, whereas not a single writing task asked students to use classification or cause and effect. Many of the writing tasks analyzed offered linguistic and/or content support through the use of models, which displays traces of the product-based approach to teaching writing. Lastly, most of the tasks lacked authenticity represented by explicit discussion of purpose and audience. Implications for L2 writing task development and writing instruction in the Korean EFL context are discussed.

• Journal of the Korean School Mathematics Society
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• v.2 no.1
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• pp.157-166
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• 1999

Compared with other subjects, mathematics has great differences in achieve-ment. In hope of solving this problems, most schools try the level-movement learning. Although they say it may have some effect because of its homogeneous group, the level groups still have differences in achievement in their students abilities. So, this study aims to present an appropriate tasks for the advanced, intermediate and beginner groups and to help self-directed learning by selecting an appropriate tasks for the students' own level. To achieve thiese goals, a great deal of level tasks were developed and given to the students. After lettins them an select appropriate tasks for their own level and perform self-directed learning, the tasks were measured carefully for their interest, attitude and achievement in learning. Consequently, we tried a new method to improve uniformity and to turn teacher-centered learning into student-centered learning. The following is the conclusion to this study. First, self-directed learning based on the selection of level tasks has meaningful effects on learning achievement in mathematics, especially for the beginner group. Second, though the above method did not improve an interest for mathematics, but was very effective in the improvement of learning attitudes.

• Journal of Family Resource Management and Policy Review
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• v.8 no.2
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• pp.15-26
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• 2004

This research evaluated counseling tasks performed by consumer counselors between Korea and Japan. Results of this research could be summarized as follows. First, not only female but also male counselors occupied counseling tasks in Korea, in Japan, all counselors were female, most of whom were married and older than in Korea. The average number of counselors in Korea was large than those in Japan, but income of counselors was higher in Japan. Average numbers of counseling were large, the level of perception on the significance of counseling tasks was lower in Korea, but degree of job satisfaction was higher in Korea than their Japanese counterparts. Second, evaluation scores of Korean counselors were higher than those in their Japanese counterparts in the light of objectiveness and fairness of counseling. On the other hand, the degree of job satisfaction among counselors and their perceptions on the significance of counseling tasks affected the evaluation scores. In contrast, both degree of job satisfaction and hours of job-training education generated those impacts. finally, Korean counselors highly evaluated their agencies' counseling tasks than their Japanese counterparts. In sum, this study showed that the overall performance of consumer counseling tasks was more positive in Korea than in Japan.

• Education of Primary School Mathematics
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• v.10 no.2
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• pp.77-110
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• 2007

This study attempted to investigate how to students show high-level mathematical thinking in math classes. This paper describes how to setup the task for lead to a high - level of thinking out students and what efforts are required while a teacher tried to maintaining students's high-level cognition during the tasks implemented. The researcher as teacher analyzed the tasks of length measurement unit in 2-Ga elementary math textbooks, modified and created math tasks demanded students' high-level cognition, made instruction plans, and implemented those tasks maintaining the levels of cognitive demand of tasks. After that, the researcher reflected and analyzed the levels of cognitive demand of tasks of instruction and factors that cause to change intended high-level cognitive demand. After reflection, second roof of action research was conducted to 2-Na length measurement unit. This paper includes those results and reflections of practitioner.