• Journal of Information Technology Applications and Management
• /
• v.27 no.6
• /
• pp.31-51
• /
• 2020

During the last decade, social live streaming service like Periscope, Ustream, and YouNow has developed from a niche market into a mainstream activity. In this media environment, social live streaming service has a tremendous impact on the social behaviors of users. Despite the rapid development, there are a lack of studies to make better understand the media environment changes through social live streaming service. This study adopted an affordances approach that leads us to identify six distinctive social affordances (visibility, accessibility, information sharing, social interaction, role-taking, interactive revenue) for user engagement in social live streaming service. Specifically, this study explores the impact of social affordances on perceived flow, followed by user engagement including passive and active engagement. Empirical data analysis with 258 questionnaires suggests that social affordances affected users' flow perception, and flow has an effect on active as well as passive engagement. Contrary to the expectation in a hypothesized research model, only the impact of accessibility on flow was rejected.

• Educational Technology International
• /
• v.23 no.2
• /
• pp.129-155
• /
• 2022

This study sought to design and develop an interactive video player (IVP) capable of promoting student engagement through the use of online video content. We designed features built upon interactive, constructive, active, passive (ICAP), and crowd learning frameworks. In the development stage of this study, we integrated numerous interactive features into the IVP intended to help learners shift from passive to interactive learning activities. We then explored the effectiveness and usability of the developed IVP by conducting an experiment in which we evaluated students' exam scores after using either our IVP or a conventional video player. There were 158 college students who participated in the study; 76 students in the treatment group used the IVP and 82 students in the control group used a conventional video player. Results indicate that the participants in the experiment group demonstrated better achievement than the participants in the control group. We further discuss the implications of this study based on an additional survey that was administered to disclose how usable the participants perceived the IVP to be.

• Educational Technology International
• /
• v.24 no.1
• /
• pp.81-114
• /
• 2023

The study aimed to qualitatively examine middle school students' engagement in distance instruction during the COVID-19 pandemic. The participants comprised 119 students from a girls' middle school in Seoul, South Korea. To gain an in-depth understanding of the students' experiences, we collected their reflective journals, which included structured items about their learning engagement at three timepoints in 2020: April, July, and December. The following are the results: 10 themes and 18 concepts were derived, and they were integrated into causal conditions (sudden transition due to COVID-19), contextual condition (technology readiness, school education context), central phenomena (high level of behavioral engagement, low emotional engagement), interventional conditions (recognizing the potential of online learning, situational awareness about COVID-19 and online learning), action/interaction phenomena (development and use of self-regulated learning strategies), and consequences (changes in practices and perception towards online learning). Based on the findings, engagement patterns of the participants were classified into five types: proactive, conservative, receptive, reactive, passive learners. The present study demonstrated important findings that are essential for the improvement and development of engaging online learning strategies in the future.

• Knowledge Management Research
• /
• v.23 no.2
• /
• pp.211-228
• /
• 2022

As social media marketing becomes prevalent, it is necessary to understand the administrative role of managers in promoting user engagement. However, little is known about how community managers enhance user engagement in social media. In this research, we study how managers can boost online user participation, including clicking likes and writing comments. Using the SUR (Seemingly Unrelated Regression) model, we find out that the active participation of managers increases user engagement of both passive (likes) and active (comments) ones. In addition, we find that the number of emotional words included in posts has a positive effect on the passive engagement whereas it negatively affects the active engagement. Lastly, the congruency between posts and comments positively affects users' passive engagement. This study contributes to prior literature related to online community management and text analyses. Furthermore, our findings offer managerial insights for practitioners and social media managers to further facilitate user engagement.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.351-354
• /
• 1996

A new target adaptive guidance (TAG) algorithm is proposed to engage the aim point formed by adding a bias to the information from an infrared (IR) seeker for improving passive homing guidance effectiveness. The TAG algorithm utilizes an observability enhancing mid-course guidance algorithm to obtain convergent estimates of state variables involved particularly in range channel otherwise unavailable from passive sensors. Simulation results indicate that the TAG algorithm provides improved terminal effectiveness without computational complexities.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.5 no.2
• /
• pp.185-194
• /
• 2002

To extract relative ranges from LOS(line of sight) information, we propose a passive ranging filter which is suitable for anti-ship missiles in HOJ(home on jam) mode. The proposed filter is devised to cope with the case that a passive ranging filter may include a large initial range estimation error since modem jammers are capable of very long range jamming. In addition, under the assumption that the missile motion is dominant over the HOJ engagement situation, the engagement geometry is modeled by a second order system. A new passive ranging filter is proposed by constructing an extended Kalman filter(EKF) based on the model. And then a least square initial state error estimation algorithm is attached to the EKF. Simulation results show that the proposed filter has a good range estimation performance with small computational load.

• Ocean Systems Engineering
• /
• v.7 no.3
• /
• pp.247-273
• /
• 2017

Many different engagement situations require naval ships to achieve some level of effectiveness. The performance of the naval ships is very important for such effectiveness. There have been many studies that analyze the effectiveness and the performance. The former are largely related to engagement level simulations, while the latter are largely related to engineering level simulations. However, there have been few studies that consider both the engagement level and the engineering level at the same time. Therefore, this study presents three case studies using engagement simulation of the engineering level to check the performance of the related parameters. First, detection performance simulations are carried out by changing the specifications of the passive sonars of a submarine in different scenarios. Maneuvering performance simulations are carried out by changing the specification of the hydroplanes of a submarine in different scenarios. Lastly, in order to check whether or not our forces would succeed in attacking enemy forces, we perform an engagement simulation with various naval ship models that consist of several engineering level models, such as command systems, weapon systems, detection systems, and maneuver systems. As a result, the performance according to the specifications of the naval ships and weapons is evaluated.

• Korean Journal of Child Studies
• /
• v.28 no.5
• /
• pp.297-307
• /
• 2007

This study investigated relationships between engagement in joint attention and the early language development in infancy. Subjects were 12 infants and their mothers. At 20 and 25 months of age, each child's spontaneous natural speech during interaction with his/her caregiver was videotaped for about 30 minutes. The EJA(Episodes of joint attention) focus between mother and child were identified and coded by Tomasello and Todd's(1983) and Bakeman and Adamson's(1984) including person engagement, object engagement, looking engagement, passive joint attention, coordinated joint attention. Results showed that a significant difference in infant's language development between within and outside EJA at 20 and 25 months of age; that is, during periods of EJA children talked more inside than outside EJA.

• The Journal of the Acoustical Society of Korea
• /
• v.18 no.6
• /
• pp.9-16
• /
• 1999

As a part of target motion analysis(TMA) with highly noisy bearings-only measurements from a passive sonar system, a nonlinear batch estimator is proposed to provide the initial estimates to a sequential estimator called the modified gain extended Kalman filter(MGEKF). Based on the system observability analysis of passive target tracking, a practical and effective method is suggested to determine the observer maneuvers for improved TMA performance through system observability enhancing. Also suggested is a method to determine observer location for enhanced system observability at the initial phase of TMA from various engagement boundaries which represent the relationship between observer-target relative geometrical data and system observability. The proposed TMA methods are tested by a series of computer simulation runs.

• Journal of Ocean Engineering and Technology
• /
• v.35 no.3
• /
• pp.238-246
• /
• 2021

The survivability of a naval ship is the ability of the ship and its onboard systems to remain functional and continue a designated mission in man-made hostile environments. A passive decoy system is primarily used as a weapon system for improving the survivability of a naval ship. In this study, an engagement scenario-based simulation program was developed for decoy effectiveness assessments against an anti-ship missile (ASM), which tracks a target with sea-skimming and active radar homing. The program can explain the characteristics of a target ship, such as the radar cross section and evasive maneuvers, as well as the operational performance of the onboard decoy system, the guidance method of the ASM, and the engagement environment's wind speed and direction. This paper describes the theory and formulations, configuration, and user interface of the developed program. Numerical examples of a decoy effect assessment of a virtual naval ship against an ASM are presented.