• Journal of KIISE:Information Networking
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• v.35 no.5
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• pp.453-463
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• 2008

The missing child problem is no more a personal problem. It became a social problem that all parents must consider. To this, this study applies USN/RFID technology integrated with GIS for the prevention of missing child. Although RFID is not designed for location sensing, but now it is regarded as a device to facilitate real time location awareness. Such advantages of RFID can be integrated with 4S(GIS/GPS/LBS/GNSS) achieving much synergy effects. In order to prevent kidnapping and missing child, it is necessary to provide a missing child preventing system using a ubiquitous computing system. Therefore, the missing child preventing system has been developed using high-tech such as RFID, GPS network, CCTV, and mobile communication. The effectiveness of the missing child prevention system can be improved through an accurate location tracking technology. This study propose and test a location sensing system using the active RFID tags. This study verifies technical applied service, and presents a system configuration model. Finally, this paper confirms missing child prevention system utilization possibility.

• Journal of Internet Computing and Services
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• v.12 no.2
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• pp.135-147
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• 2011

As the number of elderly people living alone has been increasing in the recent years, systems for their safety have been required, and some related services or pilot systems have been operating. These systems provide the monitoring service for the activities of the elderly people living alone with indoor location tracking technology using the various sensors. However, most systems provide services on expensive infrastructure such as attached tags and mobile devices. In this point, this paper attempts to suggest a system based on low cost sensors to collect event data in home environment. And a main characteristic of the system is that people can monitor the results of provided services through web browser in real time and the system can provide related context information to guardians and health care managers through SMS of mobile phone.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.29 no.5
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• pp.247-259
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• 2017

Numerical model with LPT (Lagrangian Particle Tracking) module was used to understand the variation of residence time in the outer sea of the Sihwa lake result operating from the Sihwa tidal power plant. Numerical model was composed in order to investigate the spatial distribution characteristics, the average residence time in each area was calculated by dividing the outer sea area of Sihwa lake into 4 areas. The average residence time of the areas appeared to be increase as it entered the areas located in the inner bay (13 days) from the area located in most outer sea (3 days) both before and during operation. Variation of average residence time by areas were increased in the area that was located in the most outer sea of during operation compared to before operation, and decreased in the other area. Artificial discharges from tidal power plant induces particle traps in the formation of vortex in the area located in the most outer seas, entrainment in the remaining areas, which affects variation in residence time. In other words, the jet flow generated during drainage and the change in the residence time due to the vortex and entrainment action indicate the increase horizontal mixing of water in the outer sea and in the inner bay.

• Journal of Science Education
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• v.42 no.2
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• pp.132-147
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• 2018

The goal of this research is to suggest a theoretical process-centered assessment model based on Learning Progressions of key competencies in the context of STEAM instructions. The "Process-Products Combined Module-type (P2CM) STEAM Assessment Model (P2CM STEAM Assessment Model, hereafter) can be used both as an instructional model and as an assesment model, applicable for various STEAM topics and instructional types. consists of 3 axes. The first X axis stands for 4C competencies that should be emphasized through STEAM instruction. The second Y axis stands for the types and the hierarchy of STEAM instructions. The third Z axis stands for the assessment standards based on LP. We also exemplified an assessment module combined creativity competency with creativity-based instruction based on . Based on the research results, we suggested elaboration of assessment models based on Korean LP research outcomes, development and supply of formative assessment models through field-based in-depth research, modification of formative assessment models with the participation of teacher communities and in-service teachers, and the necessity of further research on assessment models for tracking LP.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.05a
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• pp.246-247
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• 2018

Since the routes within VTS areas include harbour limit of major ports, there are sections where the traffic volume increases and the routes are normally narrow according to the geographical conditions. In the case of ports and VTS areas located on the west coast of Korea, it is affected by strong current due to large tidal differences. In this paper, we propose a method to produce useful information according to the change of navigation environment by analyzing the characteristics of ship's movement according to tidal stream or current. The SVR seaway model, support vector regression, and grid search were conducted in order to extract models.

• Smart Structures and Systems
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• v.31 no.3
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• pp.283-299
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• 2023

Structural stability of floating platforms has long since been a crucial issue in the field of marine engineering. Excessive motions would not only deteriorate the operating conditions but also seriously impact the safety, service life, and production efficiency. In recent decades, several control devices have been proposed to reduce unwanted motions, and an attractive one is the tuned heave plate (THP). However, the THP system may reduce or even lose its effectiveness when it is mistuned due to the shift of dominant wave frequency. In the present study, a novel adaptive tuned heave plate (ATHP) is proposed based on inerter by adjusting its inertance, which allows to overcome the limitation of the conventional THP and realize adaptations to the dominant wave frequencies in real time. Specifically, the analytical model of a representative semisubmersible platform (SSP) equipped with an ATHP is created, and the equations of motion are formulated accordingly. Two optimization strategies (i.e., J₁ and J₂ optimizations) are developed to determine the optimum design parameters of ATHP. The control effectiveness of the optimized ATHP is then examined in the frequency domain by comparing to those without control and controlled by the conventional THP. Moreover, parametric analyses are systematically performed to evaluate the influences of the pre-specified frequency ratio, damping ratio, heave plate sizes, peak periods and wave heights on the performance of ATHP. Furthermore, a Simulink model is also developed to examine the control performance of ATHP in the time domain. It is demonstrated that the proposed ATHP could adaptively adjust the optimum inertance-to-mass ratio by tracking the dominant wave frequencies in real time, and the proposed system shows better control performance than the conventional THP.

• Journal of the Korea Convergence Society
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• v.7 no.5
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• pp.29-34
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• 2016

Recently, with the development of high-tech industry, the use of the drones in various aspects of daily life is rapidly advancing. With technical and functional advancements, drones have an advantage of being easy to be utilized in the areas of use according to various lifestyles. In addition, through the diversification of the drone service converged with image processing medium such as camera and CCTV, an automated security system that can replace humans is expected to be introduced. By designing these unmanned security technology, a new convergence security drone service techniques that can strengthen the previous drone application technology will be proposed. In the proposed techniques, a biometric authentication technology will be designed as additional authentication methods that can determine the safety incorporated with security by selecting the search and areas of an object focusing on the objects in the initial windows and search windows through OpenCV technology and CAM-Shift algorithm which are an object tracking algorithm. Through such, a highly efficient security drone convergence service model will be proposed for performing unmanned security by using the drones that can continuously increase the analysis of technology on the mobility and real-time image processing.

• Asia pacific journal of information systems
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• v.22 no.4
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• pp.7-29
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• 2012

Smartphone and its applications (i.e. apps) are increasingly penetrating consumer markets. According to a recent report from Korea Communications Commission, nearly 50% of mobile subscribers in South Korea are smartphone users that accounts for over 25 million people. In particular, the importance of smartphone has risen as a geospatially-aware device that provides various location-based services (LBS) equipped with GPS capability. The popular LBS include map and navigation, traffic and transportation updates, shopping and coupon services, and location-sensitive social network services. Overall, the emerging location-based smartphone apps (LBA) offer significant value by providing greater connectivity, personalization, and information and entertainment in a location-specific context. Conversely, the rapid growth of LBA and their benefits have been accompanied by concerns over the collection and dissemination of individual users' personal information through ongoing tracking of their location, identity, preferences, and social behaviors. The majority of LBA users tend to agree and consent to the LBA provider's terms and privacy policy on use of location data to get the immediate services. This tendency further increases the potential risks of unprotected exposure of personal information and serious invasion and breaches of individual privacy. To address the complex issues surrounding LBA particularly from the user's behavioral perspective, this study applied the privacy calculus model (PCM) to explore the factors that influence the adoption of LBA. According to PCM, consumers are engaged in a dynamic adjustment process in which privacy risks are weighted against benefits of information disclosure. Consistent with the principal notion of PCM, we investigated how individual users make a risk-benefit assessment under which personalized service and locatability act as benefit-side factors and information privacy risks act as a risk-side factor accompanying LBA adoption. In addition, we consider the moderating role of trust on the service providers in the prohibiting effects of privacy risks on user intention to adopt LBA. Further we include perceived ease of use and usefulness as additional constructs to examine whether the technology acceptance model (TAM) can be applied in the context of LBA adoption. The research model with ten (10) hypotheses was tested using data gathered from 98 respondents through a quasi-experimental survey method. During the survey, each participant was asked to navigate the website where the experimental simulation of a LBA allows the participant to purchase time-and-location sensitive discounted tickets for nearby stores. Structural equations modeling using partial least square validated the instrument and the proposed model. The results showed that six (6) out of ten (10) hypotheses were supported. On the subject of the core PCM, H2 (locatability ${\rightarrow}$ intention to use LBA) and H3 (privacy risks ${\rightarrow}$ intention to use LBA) were supported, while H1 (personalization ${\rightarrow}$ intention to use LBA) was not supported. Further, we could not any interaction effects (personalization X privacy risks, H4 & locatability X privacy risks, H5) on the intention to use LBA. In terms of privacy risks and trust, as mentioned above we found the significant negative influence from privacy risks on intention to use (H3), but positive influence from trust, which supported H6 (trust ${\rightarrow}$ intention to use LBA). The moderating effect of trust on the negative relationship between privacy risks and intention to use LBA was tested and confirmed by supporting H7 (privacy risks X trust ${\rightarrow}$ intention to use LBA). The two hypotheses regarding to the TAM, including H8 (perceived ease of use ${\rightarrow}$ perceived usefulness) and H9 (perceived ease of use ${\rightarrow}$ intention to use LBA) were supported; however, H10 (perceived effectiveness ${\rightarrow}$ intention to use LBA) was not supported. Results of this study offer the following key findings and implications. First the application of PCM was found to be a good analysis framework in the context of LBA adoption. Many of the hypotheses in the model were confirmed and the high value of $R^2$ (i.,e., 51%) indicated a good fit of the model. In particular, locatability and privacy risks are found to be the appropriate PCM-based antecedent variables. Second, the existence of moderating effect of trust on service provider suggests that the same marginal change in the level of privacy risks may differentially influence the intention to use LBA. That is, while the privacy risks increasingly become important social issues and will negatively influence the intention to use LBA, it is critical for LBA providers to build consumer trust and confidence to successfully mitigate this negative impact. Lastly, we could not find sufficient evidence that the intention to use LBA is influenced by perceived usefulness, which has been very well supported in most previous TAM research. This may suggest that more future research should examine the validity of applying TAM and further extend or modify it in the context of LBA or other similar smartphone apps.

• The KIPS Transactions:PartD
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• v.11D no.5
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• pp.1167-1176
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• 2004

Along the advent of Internet technology, the computing environment has been considerably changed in many application domains. Especially, a lot of researches for e-Logistics have been done for the last 3 years. The e-Logistics means the virtual business activity and service architecture among the logistics companies based on the Internet technology. To construct effectively the e-Logistics framework, researches on the development of the Moving Object Technology(MOT) including GPS and GIS with spatiotemporal databases technique so far has been done The Moving Object Technology stands for the efficient management for the spatiotemporal objects such as vehicles, airplanes, and vessels which change continuously their spatial location along with time flows. However, most systems manage just only the location information detected lately by many reasons so that the uncertainty processing for the past and future location of the moving objects is still very hard. In this paper, we propose the moving object uncertainty model and system design for e-Logistics applications. The MOMS architecture in e-Logistics is suggested and the detailed explain of sub-systems including the uncertainty processor of moving objects is described. We also explain the comprehensive examples of MOMS and uncertainty processing in Delivery Parcel Application that is one of major application of e-Logistics domain.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.9-16
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• 2016

Wireless sensor networks (WSN) are composed of sensor nodes and a base station. The sensor nodes deploy a non-accessible area, receive critical information, and transmit it to the base station. The information received is applied to real-time monitoring, distribution, medical service, etc.. Recently, the WSN was extended to mobile wireless sensor networks (MWSN). The MWSN has been applied to wild animal tracking, marine ecology, etc.. The important issues are mobility and energy consumption in MWSN. Because of the limited energy of the sensor nodes, the energy consumption for data transmission affects the lifetime of the network. Therefore, efficient data transmission from the sensor nodes to the base station is necessary for sensing data. This paper, proposes an energy consumption model using two-tier clustering in mobile sensor networks (TTCM). This method divides the entire network into two layers. The mobility problem was considered, whole energy consumption was decreased and clustering methods of recent researches were analyzed for the proposed energy consumption model. Through analysis and simulation, the proposed TTCM was found to be better than the previous clustering method in mobile sensor networks at point of the network energy efficiency.