• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권1호
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• pp.1-17
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• 2017

Mobile Cloud Computing has become a promising computing platform. It moves users' data to the centralized large data centers for users' mobile devices to conveniently access. Since the data storage service may not be fully trusted, many public verification algorithms are proposed to check the data integrity. However, these algorithms hardly consider the huge computational burden for the verifiers with resource-constrained mobile devices to execute the verification tasks. We propose an energy-efficient algorithm for assigning verification tasks (EEAVT) to optimize the energy consumption and assign the verification tasks by elastic and customizable ways. The algorithm prioritizes verification tasks according to the expected finish time of the verification, and assigns the number of checked blocks referring to devices' residual energy and available operation time. Theoretical analysis and experiment evaluation show that our algorithm not only shortens the verification finish time, but also decreases energy consumption, thus improving the efficiency and reliability of the verification.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권11호
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• pp.5269-5286
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• 2018

Task scheduling is one of the key issues in improving system performance and optimizing resource management in cloud computing environment. In order to provide appropriate services for heterogeneous users, we propose a novel task scheduling strategy with service differentiation, in which the delay sensitive tasks are assigned to the rapid cloud with high-speed processing, whereas the fault sensitive tasks are assigned to the reliable cloud with service restoration. Considering that a user can receive service from either local SaaS (Software as a Service) servers or public IaaS (Infrastructure as a Service) cloud, we establish a hybrid queueing network based system model. With the assumption of Poisson arriving process, we analyze the system model in steady state. Moreover, we derive the performance measures in terms of average response time of the delay sensitive tasks and utilization of VMs (Virtual Machines) in reliable cloud. We provide experimental results to validate the proposed strategy and the system model. Furthermore, we investigate the Nash equilibrium behavior and the social optimization behavior of the delay sensitive tasks. Finally, we carry out an improved intelligent searching algorithm to obtain the optimal arrival rate of total tasks and present a pricing policy for the delay sensitive tasks.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.784-791
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• 2007

Most operational organization and railway authority which conduct scheduled maintenance(SM) have carried out the preventive maintenance(PM) based on the information provided from supplier and manufacturer of railway system. However these activities are far away from reality and low the efficiency, it is because an appropriate methods for system selection didn't take into account for improving maintenance efficiency. Therefore, the current SM tasks and maintenance activities lead to lots of spend on the cost and time. To solve the above problem, this thesis presents new approach methodology. This proposes the criteria for reliability centered maintenance(RCM) system selection through level of quantification of each parameter, i.e, frequency, severity and maintenance cost, etc. To do this, the field operation data and information of maintenance cost are essential. As applying this methodology, we can look forward to improving efficiency of PM/SM, and reducing cost.

• 대한인간공학회지
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• 제34권2호
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• pp.135-143
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• 2015

Objective: The purposes of this study are to investigate ergonomic problems and to propose their improving measures in office environment of big general hospitals. Background: Office tasks have varying risk factors of work-related musculoskeletal disorders (WMSDs). The first symptom resulted from the office work was recognized as an occupational disease in Korea in 1986. Although the symptoms have increased since its first recognition, there has been few study on the effect of office work environment settings. Method: First, the author took pictures of working scenes performed in three big university hospitals. Next, the pictures were analyzed in view point of ergonomics. Based on the analysis, their improving measures were proposed for reducing work stress. Results: The results showed that most physical office environment settings such as dimensions of tables/desks and chairs, leg room, thigh, knee and foot clearances, and chairs used did not satisfy the ergonomically recommended design guidelines. In addition, some clerks placed personal belongings under their desks, put monitors in high position and did not lean against the backrest of chairs in seated tasks, which resulted in poor working postures of leg, back, neck etc. It is recommended that the hospital management should provide their clerks with ergonomically designed office furniture and continuously perform ergonomics training program for raising clerks' recognition for office ergonomics. Conclusion: Most office environment settings investigated in this study were not in good condition in view point of ergonomic design for the settings. Application: It would be useful as basic data for establishing ergonomically good office environment in hospitals.

• 패션비즈니스
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• 제14권1호
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• pp.184-197
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• 2010

This study was conducted by the questionnaires to 323 undergraduate students in fashion related departments. Questionnaires were designed to ask total 23 questions including possibility of halfway dropouts, establishment of goals, self-improvement, entrance motives, satisfaction ratings of academic subjects, job prospects and path planning, amelioration of ways to instruct, desires for the integrated lessons and intense academic courses, wishes of field project education carrying out tasks, desired lecturers, and others. Results in this research were summarized as follows. To begin with, it was appeared that respondents with possibility of halfway dropouts showed considerable percentage (25.4%) and the reasons left out were various including joining the army, the poor economic conditions in family, a major not corresponding with one's aptitude. Secondly, in the extent of establishing goals and improving oneself, there was the difference between people with possibility of halfway dropouts and people without that, and it was judged that the extent of establishing goals and improving oneself as good parameters could explain halfway omission. Thirdly, the ways to teach for getting classes interesting were to make instruction according to one's capabilities, to progress systematically, and to take lessons with specific goals. Fourth, many respondents answered to want the integrated lessons, intense academic courses, and field project education carrying out tasks. Fifth, an overwhelming majority of respondents hoped instructors with a outstanding ability in business. For improvement of the ways to instruct and the role of professors, it is suggested as follows. First, students are given intelligible lessons focused on fundamental subjects fitted to their levels and also need gradual intense academic courses classified by their way directions and interests. Second, creative and individualized teaching methods depending on the majors and levels are developed to help students have strong interest in schoolwork. Third, professors are constantly to learn practical techniques and skills related to industries in step with the education goals of college. Fourth, it is desirable to adopt instructors with practical business talents rather than theoretical capabilities.

• 한국안전학회지
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• 제34권1호
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• pp.82-89
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• 2019

The importance of aviation safety has been emphasized recently due to the development of aviation industry. Despite the efforts of each country and the improvement of screening equipment, screening tasks are still difficult and detection failures are frequent. The purpose of this study was to examine the effect of feedback on improving signal detection performance applying a Simulated Baggage Screening Program(SBSP) for improving aviation safety. SBSP consists of three parts: image combination, option setting and experiment. The experimental images were color-coded to reflect the items' transmittance of the x-rays and could be combined as researchers' need. In the option, the researcher could set up the information, incentive, and comments needed for training to be delivered on a number of tasks and times. Experiment was conducted using SBSP and participant's performance information (hit, missed, false alarms, correct rejection, reaction time, etc.) was automatically calculated and stored. A total of 50 participants participated and each participant was randomly assigned to feedback and non-feedback group. Participants performed a total of 200 tasks and 20(10%) contained target object(gun and knife). The results showed that when the feedback was provided, the hit, correct rejection ratio and d′ were increased, however, the false alarms and miss decreased. However, there was no significant difference in response criteria(${\beta}$). In addition, implications, limitations of this study and future research were discussed.

• 한국초등과학교육학회지:초등과학교육
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• 제31권4호
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• pp.463-480
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• 2012

This study is intended to investigate the frequency of scientific writing tasks in Korean and American science textbooks, to compare the differences in types of posing the writing tasks according to the level of the children's scientific cognition, and to analyze the differences in the organization and development of writing ones of each chapter and thus to propose an effective way of presenting scientific writing in science textbooks. Korean 'Science' and 'Experiment Observation Workbook'and Macmillan Mcgraw-Hill(MMH) Science for fourth graders were analyzed for the purpose. The results are as follows: First, Korean textbooks contain more science writing tasks per pages, and less per chapters than MMH one. Both text books provide balanced amount of science writing tasks, yet MMH especially does systematic exercises for each chapter. Second, the qualitative analysis of the textbooks' scientific writing shows that both textbooks contain a significant amount of "understanding" and "explanatory" writing, which reflects that the purpose of writing in science textbooks is leaning towards acquiring and verifying scientific concepts. In American textbooks, however, writings utilizing extensive cognition process and materials are also present. It is necessary for textbooks to present diverse and expressive writing assignments including personal opinions. Third, there are differences in organization and development of science writing tasks. Science writing tasks in Korean textbooks are present independently with lesson objectives of the chapters and practices, while those in MMH are systematically developed. Based on these results, it is necessary to systemize the textbooks' way of presenting writing tasks for effective teaching and learning. By organizing the writing materials and thus developing diverse materials, and by implementing extensive cognitive process in the writing activities, textbooks will be able to contribute in attracting the students' interests and in improving their scientific knowledge.

• 원예과학기술지
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• 제30권4호
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• pp.449-462
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• 2012

본 연구는 신체재활을 위해 다양한 꽃꽂이 작업들을 이용하기 위해서 꽃꽂이 작업 시 주로 사용되는 작업들을 분류하고, 각 작업 수행 시 사용되는 상지의 관절가동범위와 근육 활성도를 측정하였다. 또한 꽃꽂이 작업 시 상지의 관절 가동범위와 근육활성도 측정결과를 근거로 뇌졸중 환자의 상지기능 향상을 위한 꽃꽂이 프로그램을 개발하여, 실제 임상현장에서 적용하여 그 효과를 조사하였다. 상지 움직임을 정량적으로 분석하기 위해 주요한 꽃꽂이 작업을 분류한 다음, 작업 분석을 토대로 8가지 꽃꽂이 기본 작업(자르기 1, 굵은 줄기; 자르기 2, 가는 줄기; 꽂기 1, 긴 줄기; 꽂기 2, 짧은 줄기; 말기; 관엽 이용; 휘기 1, 굵은 줄기; 휘기 2, 가는 줄기; 감기, 절화용 와이어 이용)을 재분류하였다. 강원도 소재 대학의 8명의 남학생(평균 연령 $24.1{\pm}2.5$세)들이 8가지 꽃꽂이 작업을 수행하는 동안 삼차원 실시간 동작 분석 시스템과 근 전도 측정기를 이용하여 상지의 관절가동범위와 각 근육부위별 활성도를 각각 측정하였다. 이 측정결과를 토대로 상지기능 향상을 위한 꽃꽃이 프로그램을 개발하여, 서울시 소재 재활병원에 입원한 뇌졸중 환자들을 대상으로 실시하였다. 참여대상자들의 의사에 따라 4명은 원예치료군에 나머지 4명은 작업치료군에 배정되었다. 원예치료는 1일 2회(총 33회기)로 실시되었으며, 프로그램 전과 후에 뇌졸중 환자들의 상지기능 평가를 위해서 관절가동범위와 장악력 및 전반적인 상지기능평가가 수행되었다. 꽃꽂이 작업 수행 시 어깨관절은 자르기 1 작업에서 관절가동범위의 변화가 가장 큰 것으로 나타났고, 팔꿈치 관절은 감기 작업에서, 손목부위 관절은 휘기 1 작업에서 가장 큰 관절가동 범위를 나타냈다(P < 0.001). 수행된 꽃꽂이 작업에 따라 상지 근육의 부위별 근육 활성도는 다양한 변화를 보였으며, 한 가지 작업에 대해 여러 부위의 근육들이 동시에 사용되었다(P < 0.001). 또한 같은 방법으로 수행하는 작업일지라도 재료의 굵기나 길이에 따라 관절가동범위와 근수축의 차이가 나타났다(P < 0.001). 뇌졸중 환자의 상지기능 향상을 위해 실시된 꽃꽂이 작업을 이용한 원예치료 프로그램은 뇌졸중 환자들의 상지(어깨, 팔꿈치, 손목관절)의 가동범위와 장악력 및 전반적인 상지 기능에 긍정적인 영향을 미치는 것으로 나타났다. 따라서 본 연구는 꽃꽂이의 주요 작업을 이용하여 특정 신체부위의 기능향상이 필요한 대상자의 재활치료를 위한 프로그램 개발에 유용한 기초자료를 제시하였다. 추가적으로 실제 재활환자의 상태에 따라 효율적인 맞춤형 원예치료 프로그램을 개발하여 그 효과를 규명하는 연구가 필요할 것이다.

• 한국영어학회지:영어학
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• 제1권1호
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• pp.163-185
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• 2001

Listening comprehension is an integrative and creative process of interaction through which listeners receive speakers' production of linguistic or non-linguistic knowledge. Improving listening comprehension requires continual attentiveness and interest. .Listening skill can be extended systematically only when students are frequently exposed to a wide range of listening materials with an affective, cultural, social, and psycholinguistic approach. Therefore, teachers should help students learn how to comprehend intactly the overall meaning of intended messages. Practical classroom teaching necessitates a systematic procedure in which students should take part in meaningful tasks and activities. This study purposes to investigate the effects of task-based listening comprehension instruction on improvement of EFL learners' listening comprehension and their attitude and interest. 74 freshmen who enrolled in College English conversation classes in Kongju National University participated in this study. The participants were administered listening comprehension tests and questionnaires. The results show that the listening comprehension instruction through tasks and activities has a positive impact on EFL learners' improvement of listening comprehension and their attitude and interest toward the target language as well.

• 한국생활과학회지
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• 제11권1호
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• pp.1-11
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• 2002

This paper was written to present the recent trend of juvenile delinquency within the context of family system and to provide the role and tasks of Family Science in the area of Probation and Parole System in Korea. Since Family Science provides knowledges and skills to help for both adolescents and their families by improving interactional functions, the role of Family Science was focusing more on comprehensive and integrated perspectives. The tasks of Family Science, especially, in family life education, family therapy, and family policy, were as follows: 1) to prevent recurrence of misbehavior by family life education. 2) to draw the cooperation with the judicial system. 3) to provide the advanced course for volunteers. 4) to perform crime prevention education for normal adolescents. 5) to join the official education for civil service personnel. 6) to manage group-homes after the completion of the probation period.