• Composites Research
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• v.31 no.5
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• pp.177-185
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• 2018

Fiber metal laminate (FML) is a type of hybrid composites which consist of metallic and fiber-reinforced plastic sheets. As the FML has a drawback of the delamination that is a failure of the interfacial adhesive layer, the nominal stresses and the energy release rates should be determined to identify the delamination behavior. However, it is difficult to derive the nominal stresses and the energy release rates since the operating temperature of the equipment is restricted. For this reason, the objective of this paper is to predict the mode-I nominal stress and the mode-I energy release rate of the adhesive layer using the inverse analysis based on the Levenberg-Marquardt method. First, the mode-I nominal stress was assumed as the tensile strength of the adhesive layer, and the mode-I energy release rate was obtained from the double cantilever beam test. Next, the finite element method was applied to predict the mode-I delamination behavior. Finally, the mode-I nominal stress and the mode-I energy release rate were predicted by the inverse analysis. In addition, the convergence of the parameters was validated by trying to input two cases of the initial parameters. Consequently, it is noted that the inverse analysis can predict the mode-I delamination behavior, and the two input parameters were converged to similar values.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.3
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• pp.226-232
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• 1982

The measurements of the jerking force and the tail beat by hooked carp were carried out using a strain gauge at a fish pond from July to August 1981. The maximum jerking force was sustained for a while in the initial state after a carp was hooked, but the jerking force was gradually decreased as a function of the time elapsed until the fish was utterly exhausted, and it converged to the body weight at last. The results are as follows : 1. The maximum jerking force $F_m(g)$ can be expressed with empirical formula : $$F_m=3.23W+105$$ where W (g) is the body weight. 2. Dynamic change of the maximum jerking force $F_n(g)$ by one tail beat with time $t_{n}(-10T/2{\leq}\;t_n{\leq}10T/2)$ can he induced with the equation as follows : $$F_n=(0.27W-6.52)(|t_n|+C)^{-2.10}$$ where the period T (sec) is given by the following equation with the body weight : T=0.000385W+0.193 3. The jerking force at each of the peak points $F_p$ (g) varies with the time elapsed t (sec) as following equation : $$F_{p}=(2.23W+105)e^{-{\beta}t}+W$$. The value of durability index $\beta$ was nearly zero in the initial state and about 1.7 in the exhausted state at last. 4. It was clearly shown that the change of jerking force by hooked carp was closely related to the tail beat from a paired difference T-test.

• Korean Journal of Crystallography
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• v.2 no.1
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• pp.17-22
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• 1991

The crystal structure of an acetylene sorption complex of vacuum dehydrated fully Cda+ _exchanged zeolite A has been determined from three-dimensional X-ray diffraction data gathered by counter method. The structure was solved and refined in the cubic space group Pm3m at 294(1) K, a=12.202(3) A and Z=1. We crystal was prepared by dehydration at 723 K and 2.67×104 Pa for 2 days, followed by exposure to 1.60×104 Pa of acetylene gas at 298(1) K. All six Cd2+ions per unit cell are associated with 6-oxgen rings of the aluminosilicate framework. They are distributed over two distinguished threefold axes of unit cell; two of these Cd2+ ions are recessed 0.694 into the sodalite unit from (111) plane of three 0(3)'s and each approaches three framework oxides; the other four Cd2+ ions extend approximately 0.586A into the large cavity. The four Cd2+ ions are in a near tetrahedral environment, 2.220(9)A from·three framework oxide ions and 2.74(7) A from each carbon atom of an acetylene molecule(which is here counted as a monodentate ligand). Full matrix least squares refinement converged to the final error indices R1=0.093 and R2=0.105 using the 292 independent reflections for which I>3σ(I).

• Journal of Service Research and Studies
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• v.9 no.2
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• pp.31-40
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• 2019

In this paper, we have studied the improvement of operational control for the enhancement of business continuity of information system becoming more important with the development of information technology such as big data, Iot, and artificial intelligence. The operational management and audit guidance of the current information system, which is coming in the fourth industrial age, where various services, data and industries are converged, is based on the existing general information system pattern and needs to be improved. The provision of services at fixed times is linked to the survival of enterprises and countries and serves as a key element. Therefore, it is necessary to study the application of optimized check items of the operation audits to minimize the service interruption damage of the information system and to provide the stable service in terms of business continuity management. To accomplish this, the check items presented in the operational control of the information system were derived by combining the PDCA step contents and 8 resource requirements provided in ISO 22301. From the point of view of increasing the business continuity according to the derivation criteria of the inspection items, the operational inspection check items were derived by exemplifying the improved check items and review items of the information system operation audit and the products to be checked during the operational audit. The check items were divided into management audit improvement check items for service continuity management, and operational audit improvement check items for performance and availability management. The average score of the IT professionals' survey on the suitability of the proposed checklist was 4.63, which was concluded to be appropriate.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.5
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• pp.525-534
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• 2005

A column experiment was performed to investigate the influence of the sludge cake development on the riverbed and the hydraulic gradient imposed by the drawdown at the well on the filtrate quality in order to offer a guideline in the design and operation of the riverbed filtration. Results show that the sludge cake on the riverbed plays an important role in the removal of the organic matter. Under the conditions of this study the COD removal rate increased from 17% to 50% along with the sludge cake development, which was equivalent to the BCOD removal of 22% and 67%, respectively. The active removal of the organic matter took place in the sludge cake and the upper 40 cm of the riverbed. As the flow rate increased owing to the increase in the head difference imposed on the column, the slope of the COD profile near the column inlet decreased, however, the profiles converged in about 40 cm from the inlet. In 10 days of sludge cake formation the dissolved oxygen was depleted at the depth of 70 cm, which suggests the denitrification can take place beyond the depth. This depth was further reduced to $20{\sim}40\; cm$ as the sludge cake developed. From this study the removal of organic matter can be expected through the riverbed filtration even with the depth of as shallow as 3 m, which is frequently met in Korea, while the removal of nitrogen through denitrification is not expected to be active under the condition.

• Journal of Convergence for Information Technology
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• v.10 no.11
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• pp.55-63
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• 2020

The IoT technology is a field that applies and converges the technologies in the existing industrial environment, instead of new technologies. The IoT technology is releasing various application services converged with other industries such as smart home, healthcare, construction, and automobile, and it is also possible to secure the work efficiency and convenience of users of IoT-based technologies. However, the security threats occurring in the IoT-based technology environment are succeeding to the vulnerability of the existing wireless network environment. And the occurrence of new and variant attacks in the combination with the ICT convergence environment, is causing damages. Thus, in the IoT technology-based environment, it would be necessary to have researches on the safe transmission of messages in the communication environment between user and device, and device and device. This thesis aims to design a safe communication protocol in the IoT-based technology environment. Regarding the suggested communication protocol, this thesis performed the safety analysis on the attack techniques occurring in the IoT technology-based environment. And through the performance evaluation of the existing PKI-based certificate issuance system and the suggested communication protocol, this thesis verified the high efficiency(about 23%) of communication procedure. Also, this thesis verified the reduced figure(about 65%) of the issued quantity of certificate compared to the existing issuance system and the certificate management technique.

• Journal of the Korea Convergence Society
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• v.8 no.3
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• pp.101-114
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• 2017

This is the study of descriptive research to look into influence factors about how married middle-aged male' job stress, job security, depression, family bond, subjective health status and social support have an effect on the quality life. We collected data by giving questionnaires to 149 middle-aged males between the ages of 40 to 49, living B & D metropolitan city and J city, and used the SPSS/WIN18.0 version to analyze. The correlated factors of quality of life included job stress(r=-.544, p<.001), depression(r=-748, p<.001), job security(r=.566, p<.001), subjective health status(r=.537, p<.001), family bond(r=.712, p<.001) and social support(r=.739, p<.001). Factors influencing quality of life are depression, social support, family bond, subjective health status, current employment period and regular exercise. Therefore, a good quality middle-aged life, it will be needed to lower the depression, expand the social support system, improve family bond and subjective health status, increase employment period.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.2
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• pp.86-100
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• 2015

Cloud computing is a computing term that evolved in the late 2000s, based on utility and consumption of computer resources. Google say that "Cloud computing involves deploying groups of remote servers and software networks that allow different kinds of data sources be uploaded for real time processing to generate computing results without the need to store processed data on the cloud. Cloud computing relies on sharing of resources to achieve coherence and economies of scale, similar to a utility (like the electricity grid) over a network. At the foundation of cloud computing is the broader concept of converged infrastructure and shared services. Cloud computing, or in simpler shorthand just "the cloud", also focuses on maximizing the effectiveness of the shared resources." The cloud service is a smart and/or intelligent service to save private files in any device, anytime, anywhere. Dropbox, OAuth, PAClous are required that the accumulated user's data are archives with cloud service. Currently we suggest an implementation technique to process many tasks to the cloud server with a thread pooling. Thread pooling is one of efficient implementating technique for client and service environment. In this paper, to present the implementation technique we suggest three diagrams in the consideration of software engineering.

• Journal of Internet of Things and Convergence
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• v.10 no.2
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• pp.85-91
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• 2024

In this paper, we studied projection mapping, which is being utilized as a digital canvas beyond space and time for theme parks, mega events, and exhibition performances. Since the existing projection technology used for fixed objects has the limitation that it is difficult to map moving objects in terms of utilization, it is urgent to develop a technology that can track and map moving objects and a real-time dynamic projection mapping system based on dynamically moving objects so that it can respond to various markets such as performances, exhibitions, and theme parks. In this paper, we propose a system that can track real-time objects in real time and eliminate the delay phenomenon by developing hardware and performing high-speed image processing. Specifically, we develop a real-time object image analysis and projection focusing control unit, an integrated operating system for a real-time object tracking system, and an image processing library for projection mapping. This research is expected to have a wide range of applications in the technology-intensive industry that utilizes real-time vision machine-based detection technology, as well as in the industry where cutting-edge science and technology are converged and produced.

• Journal of Distribution Science
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• v.15 no.5
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• pp.75-83
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• 2017

Purpose - With the rise of the fourth industrial revolution, it has converged with the existing industrial revolution to give shape to increased accessibility of knowledge and information. As a result, it has become easier for scholars to actively persue and compile research in various fields. This current study aims to focus and assess the current standing of KODISA: the Journal of Distribution Science (JDS), International Journal of Industrial Distribution & Business(IJIDB), the East Asian Journal of Business Management (EAJBM), the Journal of Asian Finance, Economics and Business (JAFEB) in a rapidly evolving era. Novel strategies for creating the future vision of KODISA 2020 will also be examined. Research design, data, and methodology - The current research will analyze published journals of KODISA in order to offer a vision for the KODISA 2020 future. In part 1, this paper will observe the current address of the KODISA journal and its overview of past achievements. Next, part 2 will discuss the activities that will be needed for journals of KODISA, JDS, IJIDB, EAJBM, JAFEB to branch out internationally and significant journals will be statistically analyzed in part 3. The last part 4 will offer strategies for the continued growth of KODISA and visions for KODISA 2020. Results - Among the KODISA publications, IJIDB was second, JDS was 23rd (in economic publications of 54 journals), and EAJBM was 22nd (out of 79 publications in management field journals). This shows the high quality of the KODISA publication journals. According to 2016 publication analysis, JDS, IJIDB, etc. each had 157 publications, 15 publications, 16 publications, and 28 publications. In the case of JDS, it showed an increase of 14% compared to last year. Additionally, JAFEB showed a significant increase of 68%. This shows that compared to other journals, it had a higher rate of paper submission. IJIDB and EAJBM did not show any significant increases. In JDS, it showed many studies related to the distribution, management of distribution, and consumer behavior. In order to increase the status of the KODISA journal to a SCI status, many more international conferences will open to increase its international recognition levels. Second, the systematic functions of the journal will be developed further to increase its stability. Third, future graduate schools will open to foster future potential leaders in this field and build a platform for innovators and leaders. Conclusions - In KODISA, JDS was first published in 1999, and has been registered in SCOPUS February 2017. Other sister publications within the KODISA are preparing for SCOPUS registration as well. KODISA journals will prepare to be an innovative journal for 2020 and the future beyond.