• Journal of Mechanical Science and Technology
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• v.18 no.1
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• pp.132-144
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• 2004

This paper presents a new method driving multiple robots to their goal position without collision. To consider the movement of the robots in a work area, we adopt the concept of avoidability measure. The avoidability measure figures the degree of how easily a robot can avoid other robots considering the velocity of the robots. To implement the concept to avoid collision among multiple robots, relative distance between the robots is proposed. The relative distance is a virtual distance between robots indicating the threat of collision between the robots. Based on the relative distance, the method calculates repulsive force against a robot from the other robots. Also, attractive force toward the goal position is calculated in terms of the relative distance. These repulsive force and attractive force are added to form the driving force for robot motion. The proposed method is simulated for several cases. The results show that the proposed method steers robots to open space anticipating the approach of other robots. In contrast, since the usual potential field method initiates avoidance motion later than the proposed method, it sometimes fails preventing collision or causes hasty motion to avoid other robots. The proposed method works as a local collision-free motion coordination method in conjunction with higher level of task planning and path planning method for multiple robots to do a collaborative job.

• Journal of Distribution Science
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• v.17 no.9
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• pp.5-13
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• 2019

Purpose - This study investigates the key features of Quick Response as the fundamental form of supply chain collaboration by reviewing the selected past studies. Based on the findings from the literature review, this study provides the guideline for future researchers and business practitioners who search for more advanced collaboration programs. Research design, data, and methodology - This study conducts the literature review on the past studies that had researched Quick Response. The selected studies are analyzed in terms of how to represent Quick Response in the models and which issue to address. Results - This study finds that the past studies lack a unified concept of Quick Response, and they fail to provide the consistent guideline on how to run this program in practices. The literature review also shows that only a small number of research issues has been addressed by most researchers. Conclusions - On the purpose of figuring out the real value of Quick Response, this study suggests that future studies apply its extensive application to the entire supply chain system. This study also shed light on the potential of Quick Response to be a more advanced supply chain collaboration program with additional collaborative functions other than information sharing.

• Journal of Engineering Education Research
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• v.20 no.1
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• pp.53-62
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• 2017

This paper explored how university students viewed flipped learning from their own perspectives. Using qualitative research methods, 5 students from a Computer Graphics course at a mid-scale university in Seoul were interviewed for this purpose. Researchers collected data about their learning experiences, emotions, and reflections about flipped learning in general and its components such as online materials, in-class activities, and instructor guidance. Research findings indicated that students were not so much conscious about the unfamiliarity of the class, the increased work load, nor the online lectures. They rather prioritized 'what they could actually learn' from the course, and thus defined flipped learning as a method which enabled students to constantly check and fill in the gaps in their learning through team-based activities and prompt feedback from the professor. A combination of students' positive attitude and active participation in team-based activities, the overall atmosphere of the department which supported interactivity and collaboration, the professor's emphasis on learning-by-doing and student-centered learning appeared to form their notions of flipped learning. The use of technology did not appear to heavily impact students' conceptions of flipped learning. Researchers suggest that pedagogical beliefs of the professor, culture surrounding the learner, and the good match between the course content and instructional strategies are central for designing a successful flipped learning class.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.2
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• pp.556-563
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• 2008

One of the most important issues of managing a supply chain is to determine the inventory level whenever shortage is permitted and vendor is responsible fur management of the both buyer and supplier's inventory. We present two vendor managed inventory models in the form of two-echelon supply chain models for: 1) one buyer-one supplier problem, and 2) two buyers- one supplier problem. We assume that shortage is permitted. The proposed methods of this paper provides a simple condition, which makes it easy to decide when and how vendor managed inventory model costs less than traditional one. The paper is supported with some numerical examples to show the implementation of the proposed methods.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.2
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• pp.611-627
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• 2017

For enhancing the coverage of wireless networks and increasing the spectrum efficiency, small cell networks (SCNs) are considered to be one of the most prospective schemes. Most of the existing literature on resource allocation among non-cooperative small cell base stations (SBSs) has widely drawn close attention and there are only a small number of the cooperative ideas in SCNs. Based on the motivation, we further investigate the cooperative approach, which is formulated as a coalition formation game with power control algorithm (CFG-PC). First, we formulate the downlink sub-channel resource allocation problem in an SCN as a coalition formation game. Pareto order and utilitarian order are applied to form coalitions respectively. Second, to achieve more availability and efficiency power assignment, we expand and solve the power control using particle swarm optimization (PSO). Finally, with our proposed algorithm, each SBS can cooperatively work and eventually converge to a stable SBS partition. As far as the transmit rate of per SBS and the system rate are concerned respectively, simulation results indicate that our proposed CFG-PC has a significant advantage, relative to a classical coalition formation algorithm and the non-cooperative case.

• Human Ecology Research
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• v.57 no.1
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• pp.73-89
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• 2019

This study explores the social phenomenon of the universalization of one-person households through a literature analysis and text mining in order to explore a future direction for Home Economics Education(HEE) development in the one-person household era. From 2010 to 2018, texts from newspaper articles and book content of one-person households were analyzed through R program. The results of the study are as follows. In order to develop students' competency to live a happy life in the one-person household era, it is necessary to: (1) expand the preemptive and collaborative research of HEE, (2) develop and operate a curriculum to raise the living competency to live alone, (3) expand opportunities for secondary school students as well as off-campus youth, middle-aged, and elderly students, and (4) develop various HEE's elective curriculum focusing on the ability to live as one-person household. Also, (5) in order to overcome the psychological and social poverty and isolation of one-person households, HEE should strengthen the learner's ability to form relationships through self-esteem, care of others, community life, communication and conflict resolution education. In conclusion, HEE's independent living competency, relationship formation competency, and practical problem solving competency are all necessary competencies to live in one-person households. In this study, it is meaningful to suggest a future direction for HEE and to use new research methods such as word cloud techniques in the absence of HEE's previous research in relation to the increase of one-person households.

• Journal of Information Science Theory and Practice
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• v.10 no.1
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• pp.18-29
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• 2022

This study aimed at overviewing the situation of information literacy education and research in the Association of Southeast Asian Nations (ASEAN) region, and developing an ASEAN network model on information literacy. This research used documentary and qualitative research methods. Key resources consisted of twenty bibliometric studies and related documents and two groups of key persons. The first group consisted of twenty-seven purposive key persons from eight countries, and the second group consisted of seven key persons from five countries. The research instruments comprised a data collection form and focus group/ interviewing forms. Data was collected by focus group discussion and online interviews, and qualitative content analysis was used in data analysis and presented descriptively. Research findings showed that: 1) information literacy education and research in the ASEAN region varied across countries and placed importance on the educational context. Singapore was found to be the most leading and productive country in ASEAN in information literacy with the highest number of journal articles on the international scale, and was among the most contributing groups at the regional and global level; 2) the ASEAN Network on Information Literacy (ASEAN-NIL) has been developed as a model with its principles, objectives, management system, activities, and promotion strategies. Its strengths are an integrated scope, multidimensional orientation, and interdisciplinary and collaborative partnerships at the national, regional, and international level, suitable for the ASEAN context, the online environment, and the digital educational ecosystem.

• Journal of the Korean Society of Clothing and Textiles
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• v.48 no.2
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• pp.367-381
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• 2024

The sharing economy (SE) describes an economic system in which consumers share a product or service via collaborative consumption. Reasonably, the SE receives much attention in the fashion industry as a sustainable form of consumption. However, a systematic review of the antecedents and outcomes of consumer participation in SE is limited by researchers' and practitioners' hindered understanding of what consumers expect and gain from the SE. This study offers a systematic review of the SE research conducted from January 2016 to July 2021 and proposes a conceptual model. In terms of antecedents, three factors, composed of nine categories and 153 variables, were identified: 1) consumer factors (80 variables), 2) platform/product factors (69 variables), and 3) environmental factors (4 variables). The outcomes included 14 variables divided into two categories: 1) positive outcomes (8 variables) and 2) negative outcomes (6 variables). The results provide recommendations for future research on applying the SE to the fashion sector. First, to more thoroughly investigating antecedents of consumer participation in fashion sharing, the research must focus on barriers and environmental factors, in addition to demographic and psychological variables. Secondly, research on the outcomes of participating in fashion sharing, including economic and social benefits, is needed.

• Nuclear Engineering and Technology
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• v.56 no.4
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• pp.1480-1489
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• 2024

Displacement cascade behaviors of Ti-6Al-4V alloys are investigated using molecular dynamics (MD) simulation. The embedded atom method (EAM) potential including Ti, Al and V elements is modified by adding Ziegler-Biersack-Littmark (ZBL) potential to describe the short-range interaction among different atoms. The time evolution of displacement cascades at the atomic scale is quantitatively evaluated with the energy of primary knock-on atom (PKA) ranging from 0.5 keV to 15 keV, and that for pure Ti is also computed as a comparison. The effects of temperature and incident direction of PKA are studied in detail. The results show that the temperature reduces the number of surviving Frenkel pairs (FPs), and the incident direction of PKA shows little correlation with them. Furthermore, the increasing temperature promotes the point defects to form clusters but reduces the number of defects due to the accelerated recombination of vacancies and interstitial atoms at relatively high temperature. The cluster fractions of interstitials and vacancies both increase with the PKA energy, whereas the increase of interstitial cluster is slightly larger due to their higher mobility. Compared to pure Ti, the presence of Al and V is beneficial to the formation of interstitial clusters and indirectly hinders the production of vacancy clusters.

• Journal of The Korean Association For Science Education
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• v.30 no.8
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• pp.953-970
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• 2010

The purpose of this study was to investigate the change of teacher-student interaction in a beginner secondary science teachers' class through collaborative mentoring program. Three experienced science teachers as mentors and three beginner science teachers as mentees were participated in this study. Mentors have been teaching science secondary school for more than 13 years with specialty in science education, and mentees have been teaching less than three years in secondary schools. They were matched one-toone on grounded characteristics that were revealed from pre-interview. Data collection consisted of lesson plans of mentees' classes, videotaped lessons of mentees, consultation meetings between mentors and mentees, and interviews with mentees as well as mentors. The consultation meetings and interviews were audiotaped and then transcribed with the videotaped lessons. To examine the change in teacher-student interactions, the lesson observed after four sessions of mentoring was compared to the lesson before mentoring on the basis of the analytical framework that was developed based on the interpretative approach. The analytical framework addresses the four aspects of teacher-student interaction, which include beginner of interaction (initiation), the types of the question, the student response and the feedback. After four sessions of collaborative mentoring, the beginner science teacher's classroom interactions were initiated by students more often. Teachers' questions increasingly turned into thought-provoking queries that required higherorder thinking. The students responded in the form of statements instead of asking question more frequently. Also, teachers provided more delayed feedback than immediate feedback. These changes of interaction patterns showed that students took a leading role in classroom interaction and they were encouraged to think. From this result, we argue that the beginner science teachers developed the ability to make students think and to support them in coming to an understanding of knowledge through a collaborative mentoring program.