• Journal of Distribution Science
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• v.22 no.1
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• pp.79-94
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• 2024

Purpose: The popularity of social media has altered how customers interact with businesses, and an increasing number of customers prefer to voice their complaints on social media. Bystanders can observe the customer complaint process on social media, but the impact of transparency on bystanders remains uncertain. Therefore, this study established and verified a model for defining the effect of transparency and service recovery types on bystanders. Research Design and Methodology: In this study, we used the internet survey platform "So Jump" to collect data. And we validated three studies with SPSS 26.0 and Smart PLS 4.0. Result: First, we showed that the transparency process (vs. result) is more likely to increase customer forgiveness and E-loyalty and reduce E-NWOM intention among bystanders. Second, customer forgiveness also plays a complementary mediating role between transparency and E-loyalty, as well as between transparency and E-NWOM intention. Finally, we found a modest interaction effect between transparency (process vs. result) and service recovery types (psychological vs. tangible vs. hybrid) on bystanders' customer forgiveness and E-loyalty. Conclusions: This study provides actionable recommendations for how service managers can effectively employ social media as a means for distributing feedback information to manage service recovery in the future.

• Journal of the Korean Society of Systems Engineering
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• v.19 no.2
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• pp.46-58
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• 2023

Deterministic safety analysis is a crucial part of safety assessment, particularly when it comes to demonstrating the safety of nuclear power plant designs. The traditional approach to deterministic safety analysis models is to model the nuclear core using point kinetics. However, this simplified approach does not fully reflect the real core behavior with proper moderator and fuel reactivity feedbacks during the transient. The use of Multi-Physics approach allows more precise simulation reflecting the inherent three-dimensionality (3D) of the problem by representing the detailed 3D core, with instantaneous updates of feedback mechanisms due to changes of important reactivity parameters like fuel temperature coefficient (FTC) and moderator temperature coefficient (MTC). This paper addresses a CEA ejection accident at hot full power (HFP), in which the underlying strong and un-symmetric feedback between thermal-hydraulics and reactor kinetics exist. For this purpose, a multi-physics analysis tool has been selected with the nodal kinetics code, 3DKIN, implicitly coupled to the thermal-hydraulic code, RELAP5, for real-time communication and data exchange. This coupled approach enables high fidelity three-dimensional simulation and is therefore especially relevant to reactivity initiated accident (RIA) scenarios and power distribution anomalies with strong feedback mechanisms and/or un-symmetrical characteristics as in the CEA ejection accident. The Systems Engineering approach is employed to provide guidance in developing the work in a systematic and efficient fashion.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.12
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• pp.1585-1591
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• 2011

In this paper, we present a new exoskeleton-type data glove that can sense the movement of the human finger and reflect the force to the finger. The data glove is designed on the basis of the skeletal structure of the human hand, and the finger module has 1 degree-of-freedom because it includes three four-bar mechanism joints in series and a wire-coupling mechanism. In addition, the transmission ratio of the finger module is maintained at 1:1.4:1 over the entire movement range, and hence, the module can perform both extension and flexion. In addition, to enable adduction/abduction motion of the human hand, a unique MCP joint is designed by using two universal joints. To validate the feasibility of the data glove, master-slave control experiments based on force-position control between the data glove and the robot hand are conducted.

• Database Research
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• v.34 no.3
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• pp.86-98
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• 2018

Point-of-Interest(POI) recommendation systems suggest the most interesting POIs to users considering the current location and time. With the rapid development of smartphones, internet-of-things, and location-based social networks, it has become feasible to accumulate huge amounts of user POI visits. Therefore, instant recommendation of interesting POIs at a given time is being widely recognized as important. To increase the performance of POI recommendation systems, several studies extracting users' POI sequential preference from POI check-in data, which is intended for implicit feedback, have been suggested. However, when constructing a model utilizing sequential preference, the model encounters possibility of data distortion because of a low number of observed check-ins which is attributed to intensified data sparsity. This paper suggests refinement of temporal intervals based on data confidence. When building a POI recommendation system using temporal intervals to model the POI sequential preference of users, our methodology reduces potential data distortion in the dataset and thus increases the performance of the recommendation system. We verify our model's effectiveness through the evaluation with the Foursquare and Gowalla dataset.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.10
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• pp.42-51
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• 1998

This paper suggests a congestion control scheme for CL (ConnectionLess) overlay network using the feedback loops between CL user and CL server, between CL servers, and between end-to-end CL users, and the header translation table of CL server. The CL overlay network for CBDS(Connectionless Broadhand Data Service) defined by ITU-T((International Telecommunication Union-Telecommunication) consists of CL servers which route frames and links which connect between CL user and CL server or between CL servers. In the CL overlay network, two kinds of congestion, CL link congestion and CL server congestion, may occur. We considered the schemes to solve the congestion. link-by-link method[18] has used the ABR feedback loops of ATM layer between CL user and CL server or between CL servers, and the congestion table using header translation table of CL server. As in congestion of output virtual channel this method has an effect on all the traffic transmitting through the link, then it has an effect on the traffic that has not caused the congestion. As a result, the link utilization of output virtual channel that does not bring the congestion and outputs the traffic is decreased. To overcome this drawback of link-by-link, we proposed the hybrid method that are using the ABR feedback loops of link-by-link method, the feedback loop between CL users in end-to-end, the congestion table using and the header translation table. This scheme deals with teh congestion immediately by link-by-link loops and the header translation table, and then regulates the sending rate of CL user that causes the congestion by end-to-end loop.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.7
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• pp.1287-1294
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• 2006

In many current wireless packet data system, the short-burst transmissions are used, and training overhead is very significant for such short burst formats. So, the availability of the short training sequence and the fast converging algorithm is essential in the adaptive equalizer. In this paper, the new equalizer algorithm is proposed to improve the performance of a MTLMS (multiple-training least mean square) based DFE (decision feedback equalizer)using the short training sequence. In the proposed method, the output of the DFE is fed back to the LMS (least mean square) based adaptive DEF loop iteratively and used as an extended training sequence. Instead of the block operation using ML (maximum likelihood) estimator, the low-complexity adaptive LMS operation is used for overall processing. Simulation results show that the perfonnance of the proposed equalizer is improved with a linear computational increase as the iterations parameter in creases and can give the more robustness to the time-varying fading.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.3
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• pp.28-35
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• 2011

Cooperative ARQ scheme is effective for better QoS guarantee for the next generation mobile communication systems where multimedia data transmission highly increases. In this paper, we propose a cooperative ARQ strategy in ad hoc cognitive relays for mobile multimedia communication for supporting instantaneous cooperation in MANET environment. In the proposed strategy, to support real time, delay-sensitive services, whenever a frame is transmitted from the source, each relay actively senses the SINR of the signal transmitted from the source, and determine whether to propose retransmission or not before the destination transmits feedback signal. To minimize the false retransmission decision or needless retransmission, we propose an adaptive sensing threshold optimization algorithm to maintain suboptimal sensing thresholds for each relay. By computer simulation, it is shown that the proposed cooperative ARQ retransmission scheme outperforms the conventional schemes with respect to frame transmission delay and frame loss probability in real time multimedia data transmission system.

• Journal of Advanced Navigation Technology
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• v.23 no.6
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• pp.548-553
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• 2019

Along with advanced vehicle to vehicle (V2V) communication technologies, platooning is regarded as one of the most promising form of autonomous driving solutions in order to increase road capacity. In this paper, we propose a novel V2V transmission scheme for safety message dissemination in platooning. The proposed scheme enhances the efficiency of channel access and multi-vehicle orthogonal frequency division multiple access (OFDMA) transmission by taking advantage of triggered uplink access technique and null data packet feedback report protocol introduced in the sixth generation WLAN standard, IEEE 802.11ax. The simulation results prove that the proposed scheme outperforms the conventional IEEE 802.11 transmission scheme throughout all measured vehicle density range.

• The Journal of the Korea Contents Association
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• v.15 no.10
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• pp.669-678
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• 2015

This study aims at investigating students' perceptions and peer feedback to practicum for teaching English in the English Department at a Korean university. The participants were forty-two students at an elective course, 'Method for teaching English', and the data comprised questionnaire, 12 teams of practicum, and 15 sets of PF. A 'Word Count System (WCS)' was adopted to analyze the data. The findings show that students regarded 'practicum' (52.4%) as more important than 'teacher's lectures' (42.8%), and most students (80%) applied more than 70% of lesson plans to their practicums. The practicum gave them experience of a teacher, development of confidence, recognition on their weaknesses and values of teaching. While the strengths shown in PF were mainly 'teaching methods and technique', 'use of multimedia', and 'teaching materials', the weaknesses were 'classroom interactions', 'teaching methods and techniques' and 'use of blackboard'. Overall praises were 1.8 times more than the matters which needed to be developed. The conclusion suggest that the students had their own insights toward teaching practices and how learners can be motivated.

• Journal of Digital Convergence
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• v.19 no.9
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• pp.1-8
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• 2021

The purpose of this study is to identify the influence of users' satisfaction with the Automatic Writing Evaluation(AWE) on learners' sense of learning achievement through self efficacy in English writing class. AWE is a tool that automatically provides feedback on writing outputs by AI technology. College students were asked to write essays for each topic and use AWE to get feedback on their drafts, and finally revise them referring to the feedback. A questionnaire survey was conducted for the data collection. The data was analyzed using SPSS, and smart PLS-SEM along with bootstrapping techniques, The results of the study reveal the followings: 1) the convenience and usefulness of AWE had a positive effect on the willingness to reuse it; 2) the satisfaction with AWE had a positive effect on self-efficacy; 3) self-efficacy had a positive effect on learning achievement in terms of emotional and linguistic aspects. With the development of the 4th industry and A.I. technology, it is recommended to introduce new materials or programs such as AWE in English education.