• KIPS Transactions on Computer and Communication Systems
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• v.3 no.10
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• pp.337-350
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• 2014

Internet-of-Things(IoT) is the computing paradigm converged with different technologies, where diverse devices are connected via the wireless network, acquire environmental information from their equipped sensors, and are actuated. IoT applications provide smart services to users by interacting with multiple devices connected to the network. IoT devices provide the simple set of the information and also offer smart services by collaborating with other devices. That is, IoT applications always interact with IoT devices which are becoming very popular at a fast pace. However, due to this fact, developing IoT application results in unconventional technical challenges which have not been observed in typical software applications. Moreover, since IoT computing has its own characteristics which are distinguished from other former paradigms such as embedded computing and mobile computing, IoT applications also reveal their own technical challenges. Therefore, we analyze technical challenges occurring in developing IoT applications and present effective solutions to overcome the challenges. To verify identified issues and presented solutions, we present the result of performing a case study of developing an IoT application. Through the case study, we verify how the unconventional technical issues are raised in a real domain and analyze effectiveness of applying the solutions to the application.

• Journal of the Korean Chemical Society
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• v.36 no.1
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• pp.87-94
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• 1992

The elution behavior of polystyrenes(PS), polymethylmethacrylates (PMMA), polybutadienes(PB), PS-PMMA(SM) block copolymers and PS-PB star shaped copolymers on the cross-linked polystyrene gels was studied. An interpretation was proposed for the plots of log hydrodynamic volume versus retention volume of solutes in the mobile phases such as tetrahydrofuran, toluene, chloroform, methylene chloride and tetrahydrofuran-cyclohexane mixture. In order to predict the retention of solutes from their physical properties, multiple stepwise regression analysis was applied to obtain the correlation. The distribution coefficients($K_p$) of solute-gel interactions in GPC for homopolymers and PS copolymers were also obtained in terms of network-limited separation mechanism. In the cases of PS and PB, $K_p$ values approach unity, while $K_p$ values for PMMA decrease as MW increase in the good solvent, but in poor solvent, $K_p$ values increase as MW increase. $K_p$ values of PS copolymers are dependent on their MW and composition, therefore, morohology of SM block copolymer is predicted to be random phase. A single universal plot of log[η]M vs. $(V_r-V_o)/K_p$

• Convergence Security Journal
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• v.20 no.4
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• pp.143-151
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• 2020

The cyber battlefield called the fifth battlefield, is not based on geological information unlike the existing traditional battlefiels in the land, sea, air and space, and has a characteristics that all information has tightly coupled correlation to be anlayized. Because the cyber battlefield has created by the network connection of computers located on the physical battlefield, it is not completely seperated from the geolocational information but it has dependency on network topology and software's vulnerabilities. Therefore, the analysis for cyber battlefield should be provided in a form that can recognize information from multiple domains at a glance, rather than a single geographical or logical aspect. In this paper, we describe a study on the development of the cyber operation COP(Common Operational Picture), which is essential for command and control in the cyber warfare. In particular, we propose an architecure for cyber operation COP to intuitively display information based on visualization techniques applying the multi-layering concept from multiple domains that need to be correlated such as cyber assets, threats, and missions. With this proposed cyber operation COP with multi-layered visualization that helps to describe correlated information among cyber factors, we expect the commanders actually perfcrm cyber command and control in the very complex and unclear cyber battlefield.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.1
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• pp.150-163
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• 2022

Recently, the gated community has been increasing due to various reasons such as demand for differentiated areas and security, but various problems have been raised, including regional conflicts, traffic restrictions and disconnection of surrounding areas. Therefore, this study empirically considered what kind of spatial effect the gated community has on the surrounding area by analyzing the vitality using floating population big data and analyzing pedestrian accessibility using network analysis and social network analysis. As a result, it was found that the overall vitality in the study area was greatly affected by the land use and the building use. However, focusing on apartment complexes, even in the same land use, when the form of the complex is open to the outside, there is a lot of floating population, so the vitality is high. In terms of accessibility, assuming that the gated community is open, it was found that as the physical connectivity improved, there were more roads for pedestrians to choose from, and the accessibility improved as traffic and exchanges occurred in the disconnected space. The value of improving property rights and residential environment is also precious, but it is necessary to review how to reflect the improvement of local permeability in enhancing the publicness of cities and the value and direction of communities that can coexist with the region.

• The Journal of the Korea Contents Association
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• v.22 no.6
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• pp.319-328
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• 2022

The purpose of this study was to investigate the relationship between depression due to the COVID-19 pandemic and park use behaviors using on line posts. During the period of the pandemic prevention activities, text data containing both 'park' and 'depression' were collected from blogs and cafes in the search engine of Naver and Daum, then analyzed using Text Mining and Social Network techniques. As a result, the main usage behaviors of park users who mentioned depression were 'look', 'stroll(walk)' and 'eat'. Other types of behaviors were connected centering around 'look', one of the communication behaviors. Also, from CONCOR analysis, as the cluster referred from communication behavior and dynamic behavior was formed as a single behavior type, it was considered park users with depression perceived the park as the space for communication and physical activities. As the spread of COVID-19 caused the restriction of communication activities, the users might consider parks as one of the solutions. In addition, it was considered that passive usage behaviors have prevailed rather than active ones due to the depression. Resulting outcomes would be useful to plan helpful urban park for citizens. It is necessary to further analyze the park use behavior of users in relation to the period of before/after the COVID-19 pandemic and the existence/nonexistence of depression.

• Journal of the Korea Institute of Building Construction
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• v.21 no.3
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• pp.231-239
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• 2021

Entering the era of the fourth industrial revolution, information and communication technologies such as CCTV, home network systems and equipment are being used in the construction industry. In particular, in order to increase the autonomy of information and communication technologies in apartments, the government has announced an administrative revision of information and communication-related laws, and companies are focusing on developing technologies such as smart home services. In addition, most domestic and foreign studies on the information and communication work were mainly conducted on technology and management. However there is a lack of research on physical defects affecting the quality of ICT. Therefore, this study collected the defect data registered in the project management system of three domestic construction companies and classified them according to the standards of the Enforcement Decree of the Apartment House Management Act. According to the analysis of the frequency of defects work type, 88.10% of defects occurred in home network equipment work. In addition, analysis of defects type in the four detailed works showed the highest number of operation error. The cause was analyzed and prevention measures and countermeasures were presented in parts of design, construction, and maintenance. The results of this study will improve the quality of apartment housing and be used as basic data for future research on practical defect minimization and prevention measures.

• International Journal of Computer Science & Network Security
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• v.22 no.9
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• pp.35-42
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• 2022

The article deals with the role of extra-curricular work by means of multimedia technologies in order to improve the quality of training of future specialists. An important condition for achieving high results in training specialists is the optimal combination of classroom and independent extra-curricular work of students by means of multimedia technologies. Very significant is the development of student independence, the formation of skills of independent search activity, the ability to take responsibility, independently solve a problem, find constructive solutions, a way out of a crisis situation, and so on. Extra-curricular work forms students' ability to master the techniques of analysis, synthesis, generalization, comparison; develops flexibility of thinking; opens up opportunities for the development and stabilization of positive learning motives to activate the process of mastering knowledge by means of multimedia technologies as a means of forming the personality of a highly qualified specialist. The concept of multimedia as one of the priority areas of Information Technology, which plays a particularly important role in the process of informatization of education, is revealed, and its advantages in education are shown. The advent of multimedia systems optimizes transformations in education, in many areas of professional activity, science, art, etc. The necessity of distance learning to improve the quality of training of future specialists using multimedia technologies in extra-curricular work is justified. The effectiveness of pedagogical support in the process of distance learning is achieved by the following conditions, which is revealed in the article. Various forms and types of extra-curricular work of students that are used in the modern practice of the educational environment of a higher education institution are described. Scientific and informational activity is considered a key area of information activity. The analysis of scientific and information activities in the field of education allows us to identify its main functions, which emphasize the growing role of scientific information in the education system, in particular, extra-curricular work using multimedia technologies. Operational, complete, accurate, targeted information that meets objective and subjective needs becomes an important link between the field of management, science and practice.

• International Journal of Computer Science & Network Security
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• v.21 no.11
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• pp.345-353
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• 2021

Cloud computing represent a new era of computing that's forms through the combination of service-oriented architecture (SOA), Internet and grid computing with virtualization technology. Virtualization is a concept through which every cloud is enable to provide on-demand services to the users. Most IT service provider adopt cloud based services for their users to meet the high demand of computation, as it is most flexible, reliable and scalable technology. Energy based performance tradeoff become the main challenge in cloud computing, as its acceptance and popularity increases day by day. Cloud data centers required a huge amount of power supply to the virtualization of servers for maintain on- demand high computing. High power demand increase the energy cost of service providers as well as it also harm the environment through the emission of CO₂. An optimization of cloud computing based on energy-performance tradeoff is required to obtain the balance between energy saving and QoS (quality of services) policies of cloud. A study about power usage of resources in cloud data centers based on workload assign to them, says that an idle server consume near about 50% of its peak utilization power [1]. Therefore, more number of underutilized servers in any cloud data center is responsible to reduce the energy performance tradeoff. To handle this issue, a lots of research proposed as energy efficient algorithms for minimize the consumption of energy and also maintain the SLA (service level agreement) at a satisfactory level. VM (virtual machine) consolidation is one such technique that ensured about the balance of energy based SLA. In the scope of this paper, we explore reinforcement with fuzzy logic (RFL) for VM consolidation to achieve energy based SLA. In this proposed RFL based active VM consolidation, the primary objective is to manage physical server (PS) nodes in order to avoid over-utilized and under-utilized, and to optimize the placement of VMs. A dynamic threshold (based on RFL) is proposed for over-utilized PS detection. For over-utilized PS, a VM selection policy based on fuzzy logic is proposed, which selects VM for migration to maintain the balance of SLA. Additionally, it incorporate VM placement policy through categorization of non-overutilized servers as- balanced, under-utilized and critical. CloudSim toolkit is used to simulate the proposed work on real-world work load traces of CoMon Project define by PlanetLab. Simulation results shows that the proposed policies is most energy efficient compared to others in terms of reduction in both electricity usage and SLA violation.

• International Journal of Computer Science & Network Security
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• v.22 no.8
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• pp.153-162
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• 2022

Relevance. Innovative activities in education should be aimed at ensuring the comprehensive development of the individual and professional development of students. The main idea of modular technology is that the student should learn by himself, and the teacher manages his learning activities. The advantage of modular technology is the ability of the teacher to design the study of the material in the most interesting and accessible forms for this part of the study group and at the same time achieve the best learning results. Innovative Moodle technology. it is gaining popularity every day, significantly expanding the space of teaching and learning, allowing students to study inter-faculty university programs in depth. The purpose of this study is to assess the quality of implementation of the e-learning system Moodle. The study was conducted at the South Ukrainian National Pedagogical University named after K. D. Ushinsky in order to identify barriers to the effective implementation of innovative distance learning technologies Moodle and introduce a new model that will have a positive impact on the development of e-learning. Methodology. The paper used a combination of theoretical and empirical research methods. These include: scientific analysis of sources on this issue, which allowed us to formulate the initial provisions of the study; analysis of the results of students 'educational activities; pedagogical experiment; questionnaires; monitoring of students' activities in practical classes. Results. This article evaluates the implementation of the principles of distance learning in the process of teaching and learning at the University in terms of quality. The experiment involved 1,250 students studying at the South Ukrainian National Pedagogical University named after K. D. Ushinsky. The survey helped to identify the main barriers to the effective implementation of modern distance learning technologies in the educational process of the University: the lack of readiness of teachers and parents, the lack of necessary skills in applying computer systems of online learning, the inability to interact with the teaching staff and teachers, the lack of a sufficient number of academic consultants online. In addition, internal problems are investigated: limited resources, unevenly distributed marketing advantages, inappropriate administrative structure, and lack of innovative physical capabilities. The article allows us to solve these problems by gradually implementing a distance learning model that is suitable for any university, regardless of its specialization. The Moodle-based e-learning system proposed in this paper was designed to eliminate the identified barriers. Models for implementing distance learning in the learning process were built according to the CAPDM methodology, which helps universities and other educational service providers develop and manage world-class online distance learning programs. Prospects for further research focus on evaluating students' knowledge and abilities over the next six months after the introduction of the proposed Moodle-based program.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.34 no.6
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• pp.315-324
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• 2022

The experimental data obtained in a wave flume were analyzed using machine learning techniques to establish a model that predicts the input wave height of the wavemaker based on the waves that have experienced wave shoaling and to verify the performance of the established model. For this purpose, artificial neural network (NN), the most representative machine learning technique, and Gaussian process regression (GPR), one of the non-parametric regression analysis methods, were applied respectively. Then, the predictive performance of the two models was compared. The analysis was performed independently for the case of using all the data at once and for the case by classifying the data with a criterion related to the occurrence of wave breaking. When the data were not classified, the error between the input wave height at the wavemaker and the measured value was relatively large for both the NN and GPR models. On the other hand, if the data were divided into non-breaking and breaking conditions, the accuracy of predicting the input wave height was greatly improved. Among the two models, the overall performance of the GPR model was better than that of the NN model.