• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.5
• /
• pp.394-405
• /
• 2019

The purpose of this study is to clarify the concept of the frail elderly and to obtain theoretical evidence. The research method was conducted using the basic principles for conceptual analysis of Walker and Avant(2005). As a Result of a review of the literature about how to utilize the concept of a frail elderly, frail elderly might be in the intermediate state of health and disease. They can be defined as physically vulnerable in the sarcopenia, inflammation, insulin resistance, and preceding advanced disease, lead to hospitalization, falls, disability, and death. The attributes were physiological, psychological, and socio-environmental and economic factors, so they had multidimensional factors. They were required the assist daily living of another person. Also, their attributes had decreased the amount of recovery time and degree, and exhaustion. The attributes of frail elderly consisted of these facts: dynamic process, multidimensional factors, dependency, vulnerability. The frail elderly was a dynamic process that involves the possibility of change to health and disease, and include physical, mental, cognitive, and social environmental factors. In addition, the frail elderly was difficulty in daily life, physical vulnerability and difficulty in adaption. In conclusion, frail elderly as defined by the results of this study will contribute to the foundation of health care systems, including community visiting nursing to understand the level of frail elderly and systemic management to do not go into long term care.

• Journal of Navigation and Port Research
• /
• v.43 no.1
• /
• pp.23-32
• /
• 2019

In this paper, we proposed a multi-chain Time of Arrival (ToA) positioning method to estimate positions using all received Loran-C signals from multiple chains without constraining to a single chain. Conventionally, we have to choose only one chain among several available chains for position estimation using Loran-C. Therefore, the number of signals to be used for positioning is limited to three to five. In general, if more signals are used for positioning estimation, its performance tends to be improved in terms of accuracy and availability. To validate the proposed method for multi-chain Loran-C, we firstly carried out a static positioning test in land. By analyzing the test results, we confirmed that the proposed method works well under a multi-chain Loran-C scenario. Subsequently, another mobile positioning test was conducted on board a vessel under a practical application scenario. From this second test, we successfully demonstrated that the multi-chain ToA positioning method even in situations where the conventional single-chain Loran-C approach fails for positioning.

• Journal of the Korean Society for Environmental Technology
• /
• v.19 no.6
• /
• pp.576-585
• /
• 2018

Systematic management during the whole life cycle from construction to operation and maintenance is very important for the seven underground pipelines (waterworks, sewerage, electricity, telecommunications, gas, heating, oil including waterworks and sewerage). Especially, it is the construction process that affects the whole life cycle of underground buried pipeline. In order to construct a new city or to maintain different underground pipes, it is always necessary to dig the ground and carry out construction and related work. There is a possibility that secondary and tertiary breaks frequently occur in the pipeline construction process after the piping constructed first in this process. To solve this problem, a system is needed which can monitor damage in real time. However, the supply of electric power for continuous operation of the system is limited according to the environment of underground buried pipelines, so it is necessary to develop a stable electric power supply system using natural energy rather than existing electric power. In this study, we developed a system that can operate the pipeline monitoring system for long time (24 hours and 15 days) using natural energy using wind and solar light.

• The Journal of the Korea Contents Association
• /
• v.21 no.10
• /
• pp.115-126
• /
• 2021

The purpose of this study is to closely analyze the case of blended-learning in order to provide a diverse and flexible learning environment while maintaining the nature of face-to-face classes, and to identify the learning environment that supports blended-learning in each class step and the educational experience of students. The experience and satisfaction of blended learning were investigated in various ways: course evaluation, LMS activity evaluation, and questionnaire before and after the class. As a result, the blended-learning is better than the traditional face-to-face classes, in providing real-time feedback, opportunities for various interactions, and textual conversations, anytime and anywhere. In addition, as a result of the preliminary survey, as a measure to solve the opinion that concentration was reduced due to problems such as networks and felt uncomfortable in the communication part, the theory and lectures of the design practice class were conducted non-face-to-face. The individual Q&A and feedback were conducted face-to-face and non-face-to-face. As a result of the follow-up survey, it was found that concentration and efficiency could be improved. This opens up possibilities for active use of the online environment in design practice classes.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.1
• /
• pp.759-767
• /
• 2021

Most weapons systems that are Force Integration are expensive equipment that reflects the latest technology, and the operation and maintenance cost is increasing continuously. Factors that efficiently operate and maintain these weapon systems include maintenance plans, economic costs, and repair part requirements. Among them, predicting the repair parts requirements during the life cycle in advance is an important way to increase operation and maintenance cost efficiency and operating availability. The start of requirement analysis for repair parts is a calculation of the CSP (CSP: Concurrent Spare parts, CSP hereafter) that is distributed when the weapon system is deployed. The CSP is an essential component of achieving the operating availability during this period because the weapon system aims to successfully perform a given operation mission without resupply for an initial set period. In the present study, the CSP calculation method was analyzed, reflecting the failure rate and operating time of items, but the analyzed CSP was aimed at preparing for technical failure, but in the initial operating environment, it is limited in coping with unexpected failures caused by human error. The failure is not included in the scope of free maintenance and is a serious factor in making the weapon system inoperable during the initial operation period. To prevent the inoperable status of a weapon system, CSP that considers human error is required in the initial operating environment, and the calculation criteria and measures are proposed.

• Economic and Environmental Geology
• /
• v.53 no.6
• /
• pp.703-713
• /
• 2020

In many geological fields, including hydrogeology, it is of great importance to determine the heterogeneity of the subsurface media. This study briefly introduces the concept and theory of the method that can estimate the hydraulic properties of the media constituting the aquifer, which was recently introduced by Park (2020). After the introduction, the method was applied to the synthetic aquifer to demonstrate the practicality, from which various implications were drawn. The introduced technique uses a global optimization technique called the covariance matrix adaptation evolution strategy (CMA-ES). Conceptually, it is a methodology to characterize the aquifer heterogeneity by assimilating the groundwater level time-series data due to the imposed hydraulic stress. As a result of applying the developed technique to estimate the hydraulic conductivity of a hypothetical aquifer, it was confirmed that a total of 40000 unknown values were estimated in an affordable computational time. In addition, the results of the estimates showed a close numerical and structural similarity to the reference hydraulic conductivity field, confirming that the quality of the estimation by the proposed method is high. In this study, the developed method was applied to a limited case, but it is expected that it can be applied to a wider variety of cases through additional development of the method. The development technique has the potential to be applied not only to the field of hydrogeology, but also to various fields of geology and geophysics. Further development of the method is currently underway.

• The Journal of the Korea Contents Association
• /
• v.21 no.5
• /
• pp.1-10
• /
• 2021

This study empirically confirmed 'the political bias of the YouTube recommendation algorithm' and 'the selective exposure of user' to verify the Filter Bubble phenomenon of YouTube. For the experiment, two new YouTube accounts were opened and each account was trained simultaneously in a conservative and a liberal account for a week, and the "Recommended" videos were collected from each account every two days. Subsequently, through the text mining method, the goal of the research was to investigate whether conservative videos are more recommended in a righties account or lefties videos are more recommended in a lefties account. And then, this study examined if users who consumed political news videos via YouTube showed "selective exposure" received selected information according to their political orientation through a survey. As a result of the Text Mining, conservative videos are more recommended in the righties account, and liberal videos are more recommended in the lefties account. Additionally, most of the videos recommended in the righties/lefties account dealt with politically biased topics, and the topics covered in each account showed markedly definitive differences. And about 77% of the respondents showed selective exposure.

• (The) Korean Journal of Educational Psychology
• /
• v.22 no.2
• /
• pp.461-478
• /
• 2008

This study attempted to test whether or not students' collaborative argumentation and explanation activity while using concept mapping did improve understanding on texts. Total of 52 college students participated in this study. They were randomly assigned to one of four experimental conditions. The experiment lasted for two or three weeks and students were tested on comprehension level of a text material that they have studied over the period. As a result, with two independent factors of explanation and collaboration, there was a significant interaction effect without main effects. That is, individual did better when they did have to explain what they were doing. However, this is not the case when students collaborate. Students in the paired condition, they did better when they do not have to explain what they were doing with concept maps. This study showed efficiency with using computerized software does not always guarantee higher understanding on text materials. Instructional contexts and variables, collaboration and explanation, needs to be considered. Collaborating with others and explaining their own learning processes should be carefully designed when they are combined with concept mapping contexts. How to minimize learning obstacles from discussing ideas with others are a critical issue for future research.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.12 no.2
• /
• pp.111-122
• /
• 2002

Malicious attackers generally attempt to intrude the target systems by taking advantage of existing system vulnerabilities and executing readily available code designed to exploit blown vulnerabilities. To the network security administrators, the rat and minimal step in providing adequate network security is to identify existing system vulnerabilities and patch them as soon as possible. Network-based vulnerability analysis scanners (NVAS), although widely used by network security engineers, have shortcomings in that they depend on limited information that is available and generally do not have access to hast-specific information. Host-based vulnerability analysis scanner (HVAS) can serve as an effective complement to NVAS. However, implementations of HVAS differ from one platform to another and from one version to another. Therefore, to security engineers who often have to maintain a large number of heterogeneous network of hosts, it is impractical to develop and manage a large number of HVAS. In this paper, we propose an agent-based architecture named ISMAEL and describe its prototype implementation. Manager process provides various agent processes with descriptiom on vulnerabilities to check, and an agent process automatically generates, compiles, and executes an Java code to determine if the target system is vulnerable or not. The result is sent back to the manager process, and data exchange occurs in % format. Such architecture provides maximal portability when managing a group of heterogeneous hosts and vulnerability database needs to be kept current because the manager process need not be modified, and much of agent process remains unchanged. We have applied the prototype implementation of ISMAEL and found it to be effective.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.21 no.6
• /
• pp.119-132
• /
• 2011

Mobile devices such as smart phones have brought big changes to be called as 'mobile big bang' against which we can't go. Mobile banking service and MTS(Mobile Trading System) are freely available at any time, anywhere and we are able to activate communications between financial company staffs out of the office and take care of business works even remotely by using mobile devices. Mobile devices are approaching as 'smart mobile innovation' to improve an enterprise productivity and competitiveness, but threats which engaged in unfair trading behaviors or unwholesome business works in finance companies are increasing and the customer's information can be leaked out by using the nonpublic official information and mobile devices. Therefore, we have to analyze the potential problems and take the necessary countermeasures with preemptive steps to protect the customer's information and improve the financial trading soundness and fairness. In this paper, we would like to suggest countermeasures and threats against using the financial company's mobile devices focusing on the financial investment companies by 'Capital Market and Financial Investment Business Act'.