• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.24-31
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• 2020

Centralized systems in computing environments have various problems, such as privacy infringement due to hacking, and the possibility of privacy violations in case of system failure. Blockchain, one of the core technologies for the next generation of converged information, is expected to be an alternative to the existing centralized system, which has had various problems. This paper proposes a blockchain-based user authentication system that can identify users using EID in an online environment. Existing identification (ID)/password (PW) authentication methods require users to store personal information in multiple sites, and receive and use their respective IDs. However, the proposed system can be used without users signing up at various sites after the issuing of an EID. The proposed system issues an EID with a minimum of information, such as an e-mail address and a telephone number. By comparing the stability and efficiency of a centralized system, the proposed integrated authentication system proved to be excellent. In order to compare stability against existing systems, we chose attack methods and encroachments on the computing environment. To verify efficiency, the total throughput between the user's app, the issuance and certification-authority's servers, and the service provider's servers was compared and analyzed based on processing time per transaction.

• Journal of Distribution Research
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• v.15 no.5
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• pp.195-215
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• 2010

Large-scale discount stores, that were in charge of leading role up to recently, reach the limit of growth because of increasing competition, saturation of domestic market, and shortened product life-cycle. As per the limit of domestic market, large-scale discount stores are trying to various global market entry strategy and global marketing strategy like new store entry, takeover of foreign distribution chain, and global sourcing strategy. In the past, global companies of advanced country have been entering to Asian market with leading position. But, as per the rapid growth of Asian economy in the late 1980's, East Asian distribution companies like Japanese company were trying to enter the Asian market. In Asian market, starting with China, that was relatively not advanced in comparison with economic development, not only western advanced countries but also East Asian countries like Japan and Korea are entering actively for overcome their limitations of domestic market. Many of distribution companies experienced success and failure for various reason already. Korean large-scale discount stores are relatively late starters in Asian market. So, this paper purposed to review global market entry strategy of Japanese large-scale discount stores, and find out strategic implications for successful global market entry strategy of Korean large-scale discount stores.

• KIPS Transactions on Computer and Communication Systems
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• v.10 no.8
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• pp.215-222
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• 2021

In order to alleviate the limited resource problem and interference problem in cellular networks, the dual connectivity technology has been introduced with the cooperation of small cell base stations. In this paper, we design a new efficient and fair resource allocation scheme for the dual connectivity technology. Based on two different bargaining solutions - Generalizing Tempered Aspiration bargaining solution and Gupta and Livne bargaining solution, we develop a two-stage radio resource allocation method. At the first stage, radio resource is divided into two groups, such as real-time and non-real-time data services, by using the Generalizing Tempered Aspiration bargaining solution. At the second stage, the minimum request processing speeds for users in both groups are guaranteed by using the Gupta and Livne bargaining solution. These two-step approach can allocate the 5G radio resource sequentially while maximizing the network system performance. Finally, the performance evaluation confirms that the proposed scheme can get a better performance than other existing protocols in terms of overall system throughput, fairness, and communication failure rate according to an increase in service requests.

• The Journal of the Korea Contents Association
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• v.22 no.4
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• pp.145-158
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• 2022

Although the rapid development of technology has led to a swift increase in the number of companies using social networking services (SNS), it will not be accurate to say that they have fully "utilized" the functionality of SNS simply by "using" these services. Therefore, this study aims to increase the convenience of using digital technology and help SNS users in extending the functionality of these services beyond their regular use and thus, revitalize the field by increasing the service providers' efficiency. In this study, the Facebook usage status of a graduate school newspaper from an undisclosed university in Seoul was analyzed from February to December, 2021 using the participant observation method. The results of the study revealed the following: First, it is necessary to diversify the subject and type of content to ensure a continuous supply of quality content; Second, there is a need to examine the user categories and characteristics by utilizing SNS functionalities such as, the target reports and insights, and based on this, supply content that meets the needs of the users; Third, to resolve the problem of low levels of user participation and an inactive Facebook account, it is necessary to mobilize new marketing tools like online events. The significance of this study is that it confronts the real problems faced by some companies that cannot keep pace with market changes in a digital environment, identifies failure factors, and proposes solutions to them.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.2
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• pp.149-159
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• 2011

Restoring and replacing teeth with fixed prostheses commonly used in dental practice. Because of improper oral hygiene care and inaccurate laboratory procedure, complication of fixed prostheses was found in the mouth of patient. Although many efforts have been continually made to obtain the data of long term prognosis of fixed prostheses, it was difficult to do it. The purpose of this study was to evaluate the clinical status of fixed prostheses to improve the quality of dental care. In order to assess the clinical status of fixed prostheses, a total of 154 individuals (aged 22-82, 88 women and 66 men loaded with 578 unit of fixed prostheses, and 423 abutments) who visited the Department of Prosthodontics, Pusan National University Hospital, between January 2009 to December 2009 and removed old fixed prostheses were examined. The results of this study were as follows: 1. Length of service of fixed prostheses was $10.3{\pm}05.5$ years (mean), 10.0 years (median). 2. Location of fixed prostheses was found to have statistically significant influence on longevity of fixed prostheses (P<.05). The longevity of fixed prostheses was high in anterior-posterior combination region (mean:13.1, median:13.5) than anterior and posterior region. 3. Longevity of fixed prostheses made of metal was longest (mean:13.3, median:12.3). 4. Number of units in fixed prostheses was found to have no statistically significant influence on longevity of fixed prostheses (P>.05). 5. Condition of opposing dentition was found to have statistically significant influence on longevity of fixed prostheses (P>.05). The fixed prostheses lasted longest when opposed by complete denture (mean:17.1, median:19.7), removable partial denture, fixed prosthesis and natural dentition trailing behind (P<.05) 6. Periodontal disease (37.5%), dental caries (19.0%), defective margin (18.4%) were frequent complications. In 33.1% of the cases, abutment state after removing fixed prostheses was needed to be extracted.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.27 no.4
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• pp.246-257
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• 2015

The progressive degradation paths of structures have quantitatively been tracked by using stochastic processes, such as Wiener process, gamma process and compound Poisson process, in order to consider both the sampling uncertainty due to the usual lack of damage data and the temporal uncertainty associated with the deterioration evolution. Several important features of stochastic processes which should carefully be considered in application of the stochastic processes to practical problems have been figured out through assessing cumulative damage and lifetime distribution as a function of time. Especially, the Wiener process and the gamma process have straightforwardly been applied to armors of rubble-mound breakwaters by the aid of a sample path method based on Melby's formula which can estimate cumulative damage levels of armors over time. The sample path method have been developed to calibrate the related-parameters required in the stochastic modelling of armors of rubble-mound breakwaters. From the analyses, it is found that cumulative damage levels of armors have surely been saturated with time. Also, the exponent of power law in time, that plays a significant role in predicting the cumulative damage levels over time, can easily be determined, which makes the stochastic models possible to track the cumulative damage levels of armors of rubble-mound breakwaters over time. Finally, failure probabilities with respect to various critical limits have been analyzed throughout its anticipated service life.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.5893-5900
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• 2012

It is very critical to promptly maintain airway of cardiac arrest cases or serious traumatic cases. The purpose of this study is to compare intubation rate, successful rate and pre-/post-education self-confidence between laryngeal tube (LTS) and proseal laryngeal mask (PLMA), so that it may contribute to improving the ability of 119 emergency team - a pivotal role in pre-hospitalization process - to carry out advanced airway management. In order to achieve the purpose, total 60 paramedics (Class I) who worked for incumbent 119 emergency team were asked to join a practical experiment and were also divided into two groups (LTS group: 30 people, PLMA group: 30 people). In details, they were all asked to take 3 sessions of practice (5 minutes per session) using dummy model to quantitatively measure the time and success/failure of intubation and the change of their self-confidence. As a result, it was found that there were statistically significant differences in the time of intubation between LTS and PLMA group (p=.000), but there was no significant difference in the rate of successful intubation between these two groups, and self-confidence of two groups tended to significantly increase after experiment (p=.000). Conclusively, if it is necessary to promptly apply intubation to traumatic cases with immobilized cervical vertebral and lingual edema, LTS can be useful as an effective means of intubation. And it is expected that continuing intubation training using LTS will improve the ability of emergency team to perform advanced airway management for traumatic cases.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.4
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• pp.22-32
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• 2014

Durability is one of the most important and attractive subjects in concrete research field because not only durability of concrete is reduced by various degradation factors but also its reduction adversely influences the structural performance and service life of concrete structure. For this reason, a considerable amount of papers associated with concrete durability have been published and those researches were mainly focused on the changes of intrinsic properties of concrete due to chemicophysical degradations. However, the relationship between durability of concrete and structural behavior of concrete member has not been well established yet. In this study, calcium leaching degradation, a cause of concrete strength reduction, was dealt with. The experiments of compressive and flexural behavior of degraded concrete member were performed to evaluate the characteristics of structural behavior according to degradation level. Finally, the results from the experiments were compared with those obtained from nonlinear FEM analysis. The results from this study clearly showed that leaching degradation leads to decrease in compressive strength and compressive behavior evolves from brittle to ductile failure pattern during the degradation process. Load capacity and flexible rigidity of the degraded RC member decreased when the degradation level increased, in compressive zone. Additionally, it was found that the values from nonlinear FEM analysis, CDP model in ABAQUS, coincided well with the experimental results.

• Journal of the Korea Concrete Institute
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• v.17 no.4 s.88
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• pp.587-594
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• 2005

The purpose of seismic design is to ensure the serviceability of buildings against earthquake, which might be occurred during the service life of buildings, and to minimize the loss of life by preventing their failure under strong earthquake. The lack resistance of walls resulting from a tendency toward high-rise apartment buildings with shear walls and use of piloti would lead to a concentration of inelastic behaviors in their weak story. In this study, the seismic performance of reinforced concrete shear wall buildings haying piloti was analyzed by using the evaluation techniques which was proposed by FEMA 273 and ATC-40. The results from comparison with these two techniques are summarized as follows.; The results of elastic analysis method for seismic performance evaluation show that the effect of piloti and building height decrease performance index. In case of shear wall building, the state of insufficient shear stress governs their overall performance and it becomes evident in the case of the buildings with more than 25 stories. For the buildings of piloti, the change of mass, weak story, as well as insufficient shear stress, decrease the performance index rapidly compared with the performance index of the buildings without piloti. The results, obtained from the nonlinear static analysis using capacity spectrum method, indicate that the performance Point increases for the structure having Piloti and high story. Also, deformation limits of buildings satisfy the allowable criteria at the life safety level, but the immediate occupancy level is exceeded in buildings which have more than 25 stories.

• KIPS Transactions on Computer and Communication Systems
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• v.6 no.8
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• pp.359-368
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• 2017

What is the term "intelligence information society", which is a term that has been continuously discussed recently? This means that the automation beyond the limits of human ability in the whole societies based on intelligent information technology is a universalized social future. In particular, it is a concept that minimizes human intervention and continuously pursues evolution to data (or big data) -based automation. For example, autonomous automation is constantly aiming at unmanned vehicles with artificial intelligence as a key element. However, until now, intelligent information research has focused on the intelligence itself and has made an effort to improve intelligence logic and replace human brain and intelligence. On the other hand, in order to replace the human labor force, we have continued to make efforts to replace workers with robots by analyzing the working principles of workers and developing optimized simple logic. This study proposes important strategies and directions to implement intelligent information education policy and intelligent information technology research strategy by suggesting access strategy, education method and detailed policy road map for intelligent information technology research strategy and educational service. In particular, we propose a phased approach to intelligent information education such as basic intelligence education, intelligent content education, and intelligent application education. In addition, we propose education policy plan for the improvement of intelligent information technology, intelligent education contents, and intelligent education system as an important factor for success and failure of the 4th industrial revolution, which is centered on intelligence and automation.