• Proceedings of the Korean Society for Emotion and Sensibility Conference
• /
• 2012.05a
• /
• pp.36-37
• /
• 2012

• Journal of Computing Science and Engineering
• /
• v.5 no.1
• /
• pp.85-110
• /
• 2011

Achieving situation awareness is especially challenging for real-time data stream applications because they i) operate on continuous unbounded streams of data, and ii) have inherent realtime requirements. In this paper we showed how formal data stream modeling and analysis can be used to better understand stream behavior, evaluate query costs, and improve application performance. We used MEDAL, a formal specification language based on Petri nets, to model the data stream queries and the quality-of-service management mechanisms of RT-STREAM, a prototype system for data stream management. MEDAL's ability to combine query logic and data admission control in one model allows us to design a single comprehensive model of the system. This model can be used to perform a large set of analyses to help improve the application's performance and quality of service.

• The Journal of the Korea Contents Association
• /
• v.6 no.3
• /
• pp.55-62
• /
• 2006

After the advent of the Ubiquitous environment, the movement for effective information management is progressing vividly. According to this situation, this paper conducts individualized context structure for individual service and also suggests 5W1H and HFC modeling which apply using priority to manage vast context data. Thus this modeling will function as a base model to embody Ubiquitous environment and offer context based service.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.8 no.4
• /
• pp.167-175
• /
• 2012

Service-oriented Architecture(SOA) is one of the most recent trends in IT solutions. SOA is a paradigm for organizing and utilizing distributed capabilities that may be under the control of different ownership domains and implemented using various technology stacks. From a technical perspective SOA, can be considered a method for designing and developing IT systems where applications are constructed from loosely coupled and autonomous building blocks. And SOA is a very effective response to the problems faced by companies in terms of reusability, interoperability and reduce coupling between systems that implement their information systems. To exploit these advantages many organizations have decided to evolve their legacy systems towards this architecture. This paper proposes a modeling for SOA based business process generation and testing, and introduces its implementation in the BPEL. And we analyze business process between enterprises, modeling the service-oriented business process with BPEL to realization level. Also, we suggests that UML is used from high-level business problems to the process of low-level problem for Visual and effectively.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.66 no.2
• /
• pp.76-81
• /
• 2017

In this paper, the risk analysis of smart home services was implemented by applying threat modeling. Identified possible threats for safe deployment of smart home services and identified threats through the STRIDE model. Through the creation of the Attack Tree, the attackable risk was analyzed and the risk was measured by applying the DREAD model. The derived results can be used to protect assets and mitigate risk by preventing security vulnerabilities from compromising and identifying threats from adversely affecting services. In addition, the modeled result of the derived threat can be utilized as a basis for performing the security check of the smart home service.

• Korean Journal of Organic Agriculture
• /
• v.18 no.3
• /
• pp.315-329
• /
• 2010

This study focused on analysis of the satisfaction level of specialty shops for environment-friendly agricultural products (EFAP). To analyze the satisfaction level of EF AP, a series of household surveys were conducted. Questionnaire was prepared on the basis of the SERVQUAL model and the structural equation modeling was made on the basis of the contents surveyed. The main results of this study are summarized as follows. Firstly, tangibles structured with store clearance, neat uniform, information and others is the factor of service quality satisfaction. Secondly, reliability structured with service practice, problem solving, and service in accurate time is the factor of service quality satisfaction. Thirdly, assurance structured with the reliability of employees, sufficient knowledge of employees, courteous and good manner is the factor of service quality satisfaction. Fourthly, responsiveness structured with prompt service, voluntary help, customer response service and the like is the factor of service quality satisfaction. Fifthly, the sympathy structured in interest for each customer, provision of service in time convenient to use, encountering the customers with genuine feeling are the factors of service quality satisfaction. And sixthly, the service satisfaction factors would influence on the consumer behavior factors.

• Journal of Information Processing Systems
• /
• v.7 no.2
• /
• pp.287-298
• /
• 2011

Efficient service description and modeling methodologies are essential for dynamic service composition to provide autonomous services for users in ubiquitous computing environments. In our previous research, we proposed a 'u-service' ontology which is an abstract and structured concept for device operations in ubiquitous environments. One of the problems that we faced during the design process was that there are not enough standards to analyze the effectiveness of a u-service ontology. In this paper, we propose a quality evaluation model to facilitate the design process of a uservice ontology. We extract modeling goals and evaluation indicators based on the uservice description specification. We also present quality metrics to quantify each of the design properties. The experiment result of the proposed quality model shows that we can use it to analyze the design of u-service ontology from various angles. Also, it shows that the model can provide a guideline, and offer appropriate recommendations for improvements.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.6 no.6
• /
• pp.1522-1545
• /
• 2012

Call admission control (CAC) plays an important role in mobile cellular network to guarantee the quality of service (QoS). In this paper, a dynamic hybrid CAC scheme with integrated cutoff priority and handoff queue for mobile cellular network is proposed and some performance metrics are derived. The unique characteristic of the proposed CAC scheme is that it can support any number of service types and that the cutoff thresholds for handoff calls are dynamically adjusted according to the number of service types and service priority index. Moreover, timeouts of handoff calls in queues are also considered in our scheme. By modeling the proposed CAC scheme with a one-dimensional Markov chain (1DMC), some performance metrics are derived, which include new call blocking probability ($P_{nb}$), forced termination probability (PF), average queue length, average waiting time in queue, offered traffic utilization, wireless channel utilization and system performance which is defined as the ratio of channel utilization to Grade of Service (GoS) cost function. In order to validate the correctness of the derived analytical performance metrics, simulation is performed. It is shown that simulation results match closely with the derived analytic results in terms of $P_{nb}$ and PF. And then, to show the advantage of 1DMC modeling for the performance analysis of our proposed CAC scheme, the computing complexity of multi-dimensional Markov chain (MDMC) modeling in performance analysis is analyzed in detail. It is indicated that state-space cardinality, which reflects the computing complexity of MDMC, increases exponentially with the number of service types and total channels in a cell. However, the state-space cardinality of our 1DMC model for performance analysis is unrelated to the number of service types and is determined by total number of channels and queue capacity of the highest priority service in a cell. At last, the performance comparison between our CAC scheme and Mahmoud ASH's scheme is carried out. The results show that our CAC scheme performs well to some extend.

• Journal of the Korean Society of Industry Convergence
• /
• v.27 no.2_2
• /
• pp.445-456
• /
• 2024

This study aims to suggest service improvement opportunities by analyzing user review data of the top three OTT service apps(Netflix, Coupang Play, and TVING) on Google Play Store. To achieve this objective, we proposed a framework for uncovering service opportunities through the analysis of negative user reviews from OTT service providers. The framework involves automating the labeling of identified topics and generating service improvement opportunities using topic modeling and prompt engineering, leveraging GPT-4, a generative AI model. Consequently, we pinpointed five dissatisfaction topics for Netflix and TVING, and nine for Coupang Play. Common issues include "video playback errors", "app installation and update errors", "subscription and payment" problems, and concerns regarding "content quality". The commonly identified service enhancement opportunities include "enhancing and diversifying content quality". "optimizing video quality and data usage", "ensuring compatibility with external devices", and "streamlining payment and cancellation processes". In contrast to prior research, this study introduces a novel research framework leveraging generative AI to label topics and propose improvement strategies based on the derived topics. This is noteworthy as it identifies actionable service opportunities aimed at enhancing service competitiveness and satisfaction, instead of merely outlining topics.

• The Mathematical Education
• /
• v.62 no.3
• /
• pp.381-400
• /
• 2023

As the era of solving various and complex problems in the real world using artificial intelligence and big data appears, problem-solving competencies that can solve realistic problems through a mathematical approach are required. In fact, the 2015 revised mathematics curriculum and the 2022 revised mathematics curriculum emphasize mathematical modeling as an activity and competency to solve real-world problems. However, the real-world problems presented in domestic and international textbooks have a high proportion of artificial problems that rarely occur in real-world. Accordingly, domestic and international countries are paying attention to the reality of mathematical modeling tasks and suggesting the need for authentic tasks that reflect students' daily lives. However, not only did previous studies focus on theoretical proposals for reality, but studies analyzing teachers' perceptions of reality and their competency to reflect reality in the task are insufficient. Accordingly, this study aims to analyze in-service mathematics teachers' perception of reality among the characteristics of tasks for mathematical modeling and the in-service mathematics teachers' competency for designing the mathematical modeling tasks. First of all, five criteria for satisfying the reality were established by analyzing literatures. Afterward, teacher training was conducted under the theme of mathematical modeling. Pre- and post-surveys for 41 in-service mathematics teachers who participated in the teacher training was conducted to confirm changes in perception of reality. The pre- and post- surveys provided a task that did not reflect reality, and in-service mathematics teachers determined whether the task given in surveys reflected reality and selected one reason for the judgment among five criteria for reality. Afterwards, frequency analysis was conducted by coding the results of the survey answered by in-service mathematics teachers in the pre- and post- survey, and frequencies were compared to confirm in-service mathematics teachers' perception changes on reality. In addition, the mathematical modeling tasks designed by in-service teachers were evaluated with the criteria for reality to confirm the teachers' competency for designing mathematical modeling tasks reflecting the reality. As a result, it was shown that in-service mathematics teachers changed from insufficient perception that only considers fragmentary criterion for reality to perceptions that consider all the five criteria of reality. In particular, as a result of analyzing the basis for judgment among in-service mathematics teachers whose judgment on reality was reversed in the pre- and post-survey, changes in the perception of in-service mathematics teachers was confirmed, who did not consider certain criteria as a criterion for reality in the pre-survey, but considered them as a criterion for reality in the post-survey. In addition, as a result of evaluating the tasks designed by in-service mathematics teachers for mathematical modeling, in-service mathematics teachers showed the competency to reflect reality in their tasks. However, among the five criteria for reality, the criterion for "situations that can occur in students' daily lives," "need to solve the task," and "require conclusions in a real-world situation" were relatively less reflected. In addition, it was found that the proportion of teachers with low task development competencies was higher in the teacher group who could not make the right judgment than in the teacher group who could make the right judgment on the reality of the task. Based on the results of these studies, this study provides implications for teacher education to enable mathematics teachers to apply mathematical modeling lesson in their classes.