• Journal of the Korean Geotechnical Society
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• v.39 no.1
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• pp.15-25
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• 2023

Recent weather changes have led to an increase in heavy rainfall resulting in frequent large-scale slope failures. To minimize damage to life and property, a measurement system is used in slope failure warning systems. However, understanding the slope failure behavior is difficult as the measurement system only measures a specific point. Therefore, numerical analysis must be p erformed with the measurement system. The soil water characteristic curve (SWCC) drying curve and boundary conditions that consider evapotranspiration and precipitation have been applied to numerical analysis, but the hysteresis of SWCC affects the numerical analysis results. To address this, a new evapotranspiration calculation method is proposed and applied to boundary conditions, and the measurement data are compared with the results of the numerical analysis. This method takes into account the different infiltration behaviors on evapotranspiration according to the drying and wetting curves of the SWCC, and allows for a more rational prediction of water movement on unsaturated slopes.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.200-201
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• 2023

Digital twin technology is used in various fields as a method of creating a virtual world to minimize the cost of solving problems in the real world, and is also actively used in the maritime field, such as large-scale systems such as ships and offshore plants. In this paper, we tried to build a digital twin of coastal waters using a ship-handling simulator. The digital twin of the coastal waters developed in this way can be used to safely manage Korea's coastal waters, where maritime traffic is complicated, by providing a actual maritime traffic data. It can be usefully used to develop and advance technologies related to maritime autonomous surface ships and intelligent maritime traffic information services in coastal waters. In addition, it can be used as a 3D-based monitoring equipment for areas where physical monitoring is difficult but real-time maritime traffic monitoring is necessary, and can provide functions to safely manage maritime traffic situations such as aerial views of ports/control areas, bridge views/blind sector views of ships in operation.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.4
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• pp.199-208
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• 2023

Taguchi method is one of the most popular approaches for design optimization such that performance characteristics become robust to uncontrollable noise variables. However, most previous Taguchi method applications have addressed a single-characteristic problem. Problems with multiple characteristics are more common in practice. The multi-criteria decision making(MCDM) problem is to select the optimal one among multiple alternatives by integrating a number of criteria that may conflict with each other. Representative MCDM methods include TOPSIS(Technique for Order of Preference by Similarity to Ideal Solution), GRA(Grey Relational Analysis), PCA(Principal Component Analysis), fuzzy logic system, and so on. Therefore, numerous approaches have been conducted to deal with the multi-characteristic design problem by combining original Taguchi method and MCDM methods. In the MCDM problem, multiple criteria generally have different measurement units, which means that there may be a large difference in the physical value of the criteria and ultimately makes it difficult to integrate the measurements for the criteria. Therefore, the normalization technique is usually utilized to convert different units of criteria into one identical unit. There are four normalization techniques commonly used in MCDM problems, including vector normalization, linear scale transformation(max-min, max, or sum). However, the normalization techniques have several shortcomings and do not adequately incorporate the practical matters. For example, if certain alternative has maximum value of data for certain criterion, this alternative is considered as the solution in original process. However, if the maximum value of data does not satisfy the required degree of fulfillment of designer or customer, the alternative may not be considered as the solution. To solve this problem, this paper employs the desirability function that has been proposed in our previous research. The desirability function uses upper limit and lower limit in normalization process. The threshold points for establishing upper or lower limits let us know what degree of fulfillment of designer or customer is. This paper proposes a new design optimization technique for multi-characteristic design problem by integrating the Taguchi method and our desirability functions. Finally, the proposed technique is able to obtain the optimal solution that is robust to multi-characteristic performances.

• KIPS Transactions on Computer and Communication Systems
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• v.12 no.10
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• pp.291-298
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• 2023

In this paper, we study whether the programming questions of the Informatics·Computer recruitment tests were suitable for selecting teachers with required programming skills. The average points of the programming questions constituted 38%(20.8 points) of the total scores for the entire curriculum based on the results from analyzing the previous questions in the past 5 years. Moreover, the distribution of points for each evaluation criteria within programming and data structure, two exam subjects which have a high proportion of programming questions, demonstrated a large deviation ranging from 0% to 47% and 0% to 53% respectively. In this study, a questionnaire survey was conducted on 31 teachers to examine if the previous programming questions were suitable for measuring teachers' competency in programming abilities required in the actual teaching experience. Computational thinking ability was ranked the highest at 58% in response to the area that needs to be evaluated in the recruitment test. In response to the relevance of previous questions, problem solving ability was ranked the highest at 2.84 on a 5-point scale, but the overall appropriateness was deemed low. C language and Python were regarded as the computer languages suitable to be tested for programming questions with each ranked 55% and 45%. The finding confirms that teachers preferred Python and the incumbent C language to others. Based on the results of the questionnaire, we recommend changes in the programming questions to improve the selection criteria.

• Korean Journal of Remote Sensing
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• v.39 no.5_2
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• pp.743-754
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• 2023

The global occurrence of myriad natural disasters and incidents, catalyzed by climate change and extreme meteorological conditions, has engendered substantial human and material losses. International organizations such as the International Charter have established an enduring collaborative framework for real-time coordination to provide high-resolution satellite imagery and geospatial information. These resources are instrumental in the management of large-scale disaster scenarios and the expeditious execution of recovery operations. At the national level, the operational deployment of advanced National Earth Observation Satellites, controlled by National Geographic Information Institute, has not only catalyzed the advancement of geospatial data but has also contributed to the provisioning of damage analysis data for significant domestic and international disaster events. This special edition of the National Disaster Management Research Institute delineates the contemporary landscape of major disaster incidents in the year 2023 and elucidates the strategic blueprint of the government's national disaster safety system reform. Additionally, it encapsulates the most recent research accomplishments in the domains of artificial satellite systems, information and communication technology, and spatial information utilization, which are paramount in the institution's disaster situation management and analysis efforts. Furthermore, the publication encompasses the most recent research findings relevant to data collection, processing, and analysis pertaining to disaster cause and damage extent. These findings are especially pertinent to the institute's on-site investigation initiatives and are informed by cutting-edge technologies, including drone-based mapping and LiDAR observation, as evidenced by a case study involving the 2023 landslide damage resulting from concentrated heavy rainfall.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.1173-1178
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• 2023

In modern society, there is a tendency to emphasize efficiency and lead to detailed planning of team projects and individual tasks within organizations. In a 24-hour routine, the ability to use time effectively is considered an indicator of conscientiousness, and people try to imitate planned and organized people and utilize various systems to manage their daily lives. The reason why you want to perform a given task efficiently is because it affects the success or failure of the project by completing the task within a set period of time. Neglecting the project schedule is considered a major risk that threatens a successful outcome. This applies not only to large-scale organizational projects but also to individual life, and utilizes a variety of schedule management tools that emphasize time-based efficient management. In project management, it is necessary to carefully understand the detailed work progress rather than simply based on Today. In this paper, we propose an Android application that can manage schedules by accessing the user's project in units of tasks rather than dates, and introduce its implementation. The application we implemented in this paper can manage the project's goals and schedule by registering the project to which the user belongs. In addition, it provides the ability to approach work efficiently by visualizing the progress of the entire project or individual goals. As a result, users can use the application we propose in this paper to focus on their projects and manage schedules by task, thereby improving the overall efficiency of the project.

• KIPS Transactions on Computer and Communication Systems
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• v.12 no.9
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• pp.263-272
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• 2023

Industrial Internet of Things (IIoT) is an important factor in increasing production efficiency in industrial sectors, along with data collection, exchange and analysis through large-scale connectivity. However, as traffic increases explosively due to the recent spread of IIoT, an allocation method that can efficiently process traffic is required. In this thesis, I propose a two-stage task offloading decision method to increase successful task throughput in an IIoT environment. In addition, I consider a hybrid offloading system that can offload compute-intensive tasks to a mobile edge computing server via a cellular link or to a nearby IIoT device via a Device to Device (D2D) link. The first stage is to design an incentive mechanism to prevent devices participating in task offloading from acting selfishly and giving difficulties in improving task throughput. Among the mechanism design, McAfee's mechanism is used to control the selfish behavior of the devices that process the task and to increase the overall system throughput. After that, in stage 2, I propose a multi-armed bandit (MAB)-based task offloading decision method in a non-stationary environment by considering the irregular movement of the IIoT device. Experimental results show that the proposed method can obtain better performance in terms of overall system throughput, communication failure rate and regret compared to other existing methods.

• Journal of Intelligence and Information Systems
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• v.29 no.4
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• pp.51-68
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• 2023

With the emergence of the internet and the increasing use of online communities for over 20 years, the age range of users has also been rising. This study explores the linguistic changes that have occurred as the user age in online communities has increased. To do this, data was collected and analyzed from an online community that has been actively operating, despite new member registrations being closed nine years ago. By comparing the posts over an 11-year period from 2012 to 2022, changes such as an increase in average comments, a decrease in interrogative sentences, and a decrease in imperative statements were observed. The study also proposed loneliness due to aging and a decline in curiosity and confidence as potential causes of these changes. In South Korea, which is rapidly entering an aging society unprecedentedly fast on a global scale, the increase in single-person households has evolved loneliness from a personal issue to a social problem, manifested in an increase in solitary deaths and reclusive individuals. This research sheds light on one aspect of these social phenomena through the analysis of data from a large online community.

• Journal of Internet Computing and Services
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• v.21 no.1
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• pp.169-178
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• 2020

The reductions of troops/human resources, and improvement in combat power have made Korean Department of Defense actively adapt 4th Industrial Revolution technology (Artificial Intelligence, Big Data). The defense information system has been developed in various ways according to the task and the uniqueness of each military. In order to take full advantage of the 4th Industrial Revolution technology, it is necessary to improve the closed defense datamanagement system.However, the establishment and usage of data standards in all information systems for the utilization of defense big data and artificial intelligence has limitations due to security issues, business characteristics of each military, anddifficulty in standardizing large-scale systems. Based on the interworking requirements of each system, data sharing is limited through direct linkage through interoperability agreement between systems. In order to implement smart defense using the 4th Industrial Revolution technology, it is urgent to prepare a system that can share defense data and make good use of it. To technically support the defense, it is critical to develop Multi Repository Meta-Data Management (MRMM) that supports systematic standard management of defense data that manages enterprise standard and standard mapping for each system and promotes data interoperability through linkage between standards which obeys the Defense Interoperability Management Development Guidelines. We introduced MRMM, and implemented by using vocabulary similarity using machine learning and statistical approach. Based on MRMM, We expect to simplify the standardization integration of all military databases using artificial intelligence and bigdata. This will lead to huge reduction of defense budget while increasing combat power for implementing smart defense.

• Asia pacific journal of information systems
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• v.18 no.1
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• pp.53-77
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• 2008

In recent years, although numbers of corporations are bringing in PMO, they seem to be indifferent to PMO performance measurement. This demonstrates that there are also other reasons beside performance measurement of information systems (IS) project being ambiguous by introducing PMO; the lack of acknowledging the concrete function of PMO, and the scarcity of empirical study about the effect of PMO on the project members and project performance. In this sense, this study is aimed at proposing a new research model in which project success factors (i.e., standardization, management advocacy, and staff expertise) affect PMO capability (i.e., knowledge management, resources management, and problem solving competency) positively, leading to project performance (i.e., task outcomes, psychological outcomes, and organizational outcomes) eventually. To empirically test the research model, data are surveyed from PMO department and IS department. To prove the validity of the proposed research model, PLS analysis is applied with valid 132 questionnaires. By employing PLS technique, the measurement reliability and validity of research variables are tested and the path analysis is conducted to do the hypothesis testing. The path analysis results can be organized into 7 ways in large scale. First, standardization of project success factors has a positive association with knowledge management, resources management, and problem solving competency of PMO capabilities. The findings of this result indicate that the multiple or single project management should satisfy standardization in order to operate an effective PMO. Second, management advocacy of project success factors has a positive association with knowledge management, resources management, and problem solving competency. Management advocacy refers to the willingness of management to provide the required resources and authority for project success. There is agreement among researchers regarding the importance of management advocacy for favorable PMO capability. Third, staff expertise of project success factors has a positive association with knowledge management, resources management, and problem solving competency. The findings of this result indicate that the formation of an exceptional consultant or members with a proficient knowledge for staff expertise of project member is the key factor to elevate the PMO capability. Past research suggests that experience and knowledge and the resultant familiarity with the problem faced can be an important determinant of PMO capability. A capable project with appropriate staff expertise means that it enjoys a diversity of abilities and experiences. Fourth, knowledge management competency of PMO capabilities has a positive impact on psychological outcomes but has no direct effect on task outcomes and organizational outcomes. In domestic case of S. Korea, PMO was finally introduced to many other corporations in 2005 though it started bringing in 2000. Therefore, it had neither a significant impact on the task outcomes nor organizational outcomes by lacking the contents and the infrastructure of the knowledge management because the knowledge consolidation and management period of PMO is comparatively shorter by terms than other foreign nations. Fifth, resources management competency of PMO capabilities has a positive association with task outcomes, psychological outcomes, and organizational outcomes. In addition, problem solving competency of PMO capabilities has a positive association with task outcomes, psychological outcomes, and organizational outcomes. Therefore, the findings of this results stress that PMO capabilities has a positive impact on project performance. Sixth, according to the path analysis of the hypothesis, which suggested in this research, problem solving competency is the PMO capability which is the key success factor for task, psychological, and organizational outcomes as an integrated performance model. Further, the analysis reveals that problem solving competency is an important factor for integrated performance model. The finding is in line with past IS research, which affirms that the work of IS projects is essentially a problem solving endeavor. Seventh, in the path analysis of the hypothesis in this research, the path of the management advocacy $\rightarrow$ problem solving competency $\rightarrow$ organizational outcomes appears to be the most important and strongest path. In brief, the finding of this study suggests that project success factors influence PMO capability positively, and project performance as well. From the results, it can be concluded that PMO helped great improve the project success rate and project performance. This study advances research on PMO capability in three important aspects. First, the findings of our study have implications for IS theory and future research. Our study contributes to IS theory by synthesizing concepts from PMO research and project management research with those in IS research. We proposed and tested PMO capability of IS projects and the findings of our investigation provided some preliminary answers to some of the questions raised. Secondly, this thesis does not only help depicting the concept of IT governance but also approaches empirically. It makes a gradual approach to the main content, step by step, in contrary of simple standard, scholastic way of thinking. Finally, we argued that this task-oriented(technical) view is not sufficient to adequately conceptualize IS project performance. Hence, we applied that the research on organization teams, which provides a flip viewpoint to that of project management research in that it gives more weight for psychological outcomes of organizational work groups, can be very helpful in reconceptualizing the IS project performance construct. The limitations of this study are also discussed to provide research directions for future research.