• Journal of the Korean Institute of Gas
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• v.27 no.2
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• pp.71-78
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• 2023

In general, electric submersible pumps (ESPs), which have an average life of 1.0 to 1.5 years, experience a decrease in performance and a reduction in life of the pump depending on oil and gas reservoir characteristics and operating conditions in wells. As the result, the failure of ESP causes high well workover costs due to retrieval and installation, and additional costs due to shut down. In this study, a flow loop system was designed and established to predict the life of ESP in long­term operation of oil and gas wells, and the life cycle data of ESP from the time of installation to the time of failure was acquired and analyzed. Among the data acquired from the system, flow rate, inlet and outlet temperature and pressure, and the data of the vibrator installed on the outside of ESP were analyzed, and then the performance status according to long-term operation was classified into five stages: normal, advice I, advice II, maintenance, and failed. Through the experiments, it was found that there was a difference in the data trend by stage during the long­term operation of the ESP, and then the condition of the ESP was diagnosed and the failure of the pump was predicted according to the operating time. The results derived from this study can be used to develop a failure prediction program and data analysis algorithm for monitoring the condition of ESPs operated in oil and gas wells.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.3
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• pp.511-525
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• 2023

As awareness of personal data protection increases, various Full Disk Encryption (FDE)-based applications are being developed that real-time encryption or use virtual drive volumes to protect data on user's PC. FDE-based applications encrypt and protect the volume containing user's data. However, as disk encryption technology advances, some users are abusing FDE-based applications to encrypt evidence associated with criminal activities, which makes difficulties in digital forensic investigations. Thus, it is necessary to analyze the encryption process used in FDE-based applications and decrypt the encrypted data. In this paper, we analyze Cryptomator and Norton Ghost, which provide volume encryption and backup functions. We analyze the encrypted data structure and encryption process to classify the main data of each application and identify the encryption algorithm used for data decryption. The encryption algorithms of these applications are recently emergin gor customized encryption algorithms which are analyzed to decrypt data. User password is essential to generate a data encryption key used for decryption, and a password acquisition method is suggested using the function of each application. This supplemented the limitations of password investigation, and identifies user data by decrypting encrypted data based on the acquired password.

• 한국체육학회지인문사회과학편
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• v.54 no.3
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• pp.421-437
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• 2015

This study aims to examine what made leisure activities of citizens activated and to evaluate their importance and thereby to present basic data for governments at all levels via analysis of characteristics of activated leisure activities by area. To attain the objectives of the study, for a qualitative and empirical analysis to develop measuring tools, a total of 400 copies of the questionnaire, 100 copies for each of the four areas - Incheon, Daejeon, Gwangju, and Busan- were distributed and collected for a quantitative analysis such as technical statistical analysis, exploratory factor analysis and reliability analysis using a SPSS 18.0 program, with the following results: First, the qualitative analysis generated 15 factors via interviews of experts, and six factors of facilities, programs, organization and experts, promotion, policies, and other were extracted via open-end questions, comments of experts, and findings from existing literature. Second, based on the six factors extracted from the qualitative analysis, the 400 copies of the questionnaire were analyzed and, through factor analysis, the six factors were classified into four factors for facilities, two factors for leisure policies and other, respectively. In addition, questions on the promotion factor were all deleted, as they were lack in validity and reliability, resulting in 10 factors extracted in total. Third, Importance of the questions was five points or over on average, in most cases.

• Economic and Environmental Geology
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• v.56 no.3
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• pp.229-238
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• 2023

Bentonite is a type of rock that has been used as a traditional mineral medicine. It has a variety of pharmacological activities, and is used in traditional Korean medicine to treat jaundice, diarrhea, and hemostasis. In modern medicine, it is used as a raw material and additive for medicines such as antacids, gastrointestinal protective agents, and laxatives. Bentonite produced in Korea was produced through diagenesis or hydrothermal alteration of tertiary volcanic debris distributed in the Pohang and Gyeongju areas. It is mainly used for industrial purposes such as papermaking, paint, civil engineering, casting, and animal feed. Recently, technology is being developed to use it in cosmetics and pharmaceuticals. In this study, the geochemical characteristics of bentonite were identified by analyzing the main components and trace elements of 40 and 21 types of bentonite produced in the Gampo Gyeongju and Yeonil Pohang area. Also it were classifed by formation envrionment of bentonite deposits in the Gampo and Yeonil. As a result of the study, bentonite from the reserch area may be cased by argillic alteraton that alkali elements are removed form basaltic rocks by hydrothermal fluids and AI-CCPI alteration indices wrere also indentified argillic alteraton. It was found that there is a correlation between the behavior characteristics of heavy metal elements (P b, Cr, As) and the hydrothermal alteration of bentonite in the reserch area.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.582-583
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• 2021

As the production of new and renewable energy such as solar and wind power has diversified, microgrid systems that can simultaneously produce and consume have been introduced. . In general, a decrease in electricity prices through solar power is expected in summer, so producer protection is required. In this paper, we propose a transparent and safe gift power transaction system between users using blockchain in a microgrid environment. A futures is simply a contract in which the buyer is obligated to buy electricity or the seller is obliged to sell electricity at a fixed price and a predetermined futures price. This system proposes a futures trading algorithm that searches for futures prices and concludes power transactions with automated operations without user intervention by using a smart contract, a reliable executable code within the blockchain network. If a power producer thinks that the price during the peak production period (Hajj) is likely to decrease during production planning, it sells futures first in the futures market and buys back futures during the peak production period (Haj) to make a profit in the spot market. losses can be compensated. In addition, if there is a risk that the price of electricity will rise when a sales contract is concluded, a broker can compensate for a loss in the spot market by first buying futures in the futures market and liquidating futures when the sales contract is fulfilled.

• The Journal of Bigdata
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• v.7 no.2
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• pp.153-172
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• 2022

Online shopping has transformed and rapidly grown the entire market at the forefront of wholesale and retail services as an effective solution to issues such as digital transformation and social distancing policy (COVID-19 pandemic). Small business owners, who form the majority at the center of the online shopping industry, are constantly collecting policy changes and market trend information to overcome these problems and use them for marketing and other sales activities in order to overcome these problems and continue to grow. Objective and refined information that is more closely related to the business is also needed. Therefore, in this paper, through the collection and analysis of big data information, which is the core technology of digital transformation, key variables are set in product classification, sales trends, consumer preferences, and review information of online shopping malls, and a method of using them for competitor comparison analysis and business sustainability evaluation has been prepared and we would like to propose it as a service. If small and medium-sized businesses can benchmark competitors or excellent businesses based on big data and identify market trends and consumer tendencies, they will clearly recognize their level and position in business and voluntarily strive to secure higher competitiveness. In addition, if the sustainable growth of the online shopping mall operator can be confirmed as an indicator, more efficient policy establishment and risk management can be expected because it has an improved measurement method.

• Journal of Service Research and Studies
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• v.11 no.3
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• pp.98-116
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• 2021

With the advent of the era of the 4th industrial revolution, various factors such as economy, management, and culture are changing in modern society, unlike in the past. Among them, the main characteristic of management is the change from intangible goods to tangible goods, and companies are trying to pursue innovation such as introducing a new management method, converting from manufacturing to service, and expanding technology. However, with regard to human resources, which is becoming the most important for sustainable value creation in a changing era, efforts to enable practical innovation are lacking as they are still in a simple transition. Therefore, in this study, after recognizing the importance of human resources, we verified the relationship between the elements of the human resource in the service economy era according to organizational culture and organizational structure. The relationship between organizational culture and organizational structure by type was verified using the items of human resources, we verified the relationship between the elements of the human resource in the service economy era that were derived and verified in recent research. As a result, there were some significant differences in the image of human resources, we verified the relationship between the elements of the human resource by organizational culture and type of organization, but when the two factors were combined and interpreted, it was found that all of the human resources, we verified the relationship between the elements of the human resource in the service economy era were necessary. However, in order to overcome the limitation that the indicators of this study were limited, it is necessary to continue research through samples that consider various factors in the future and systematic classification by type of organization and industry by industry.

• Journal of Service Research and Studies
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• v.12 no.1
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• pp.36-48
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• 2022

As the use of smartphones has rapidly increased due to the development of digital technology, the expansion of smartphones, and the COVID-19 incident, dependence on smartphones and the Internet is emerging as a serious social problem. As one of the solutions to the smartphone overdependence problem, the government and companies are releasing smartphone overdependence prevention applications. However, research on the effectiveness of smartphone overdependence prevention applications is insufficient. Therefore, this study selects 25 applications serviced in Korea as analysis targets and evaluates smartphone overdependence prevention applications in terms of function and service using the FGI survey method to identify problems and propose improvements. In the function evaluation, the functions of blocking illegal/harmful apps/websites, limiting smartphone usage time, and monitoring smartphone usage status are provided in most applications, so satisfaction scores are also highly evaluated. However, functions such as location check, smombie prevention, and body camphishing prevention served by some applications are evaluated low due to poor performance and poor accuracy. Classified by service provider, government-providing applications need to accurately perform functions and improve convenience of use. Mobile-Carrier-providing applications need to improve connectivity with other carriers and compatibility with other smart devices like smartphone, tablet, etc. Other private enterprise-providing applications need to open AS channels such as customer service centre and chatbot to improve service.

• 한국노년학
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• v.30 no.3
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• pp.1005-1020
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• 2010

This study was conducted to explore and understand the meaning of stigma of families having old people admitted to nursing home within the Korean culture. Data collection was performed through in-depth interviews and participant observations which were recorded and transcribed verbatim with the consent of the participants. The key informants were 12 people having the aged family member in nursing home. The data was collected from October 2008 to February 2009 until completed. Data were analyzed utilizing the taxonomic analysis method developed by Spradley. As a result, 24 themes, 8 categories and 4 cultural domains are founded from the cases. The cultural domains resulted from the analysis are: 『Incompetence of Oneself: 'Adaptation to Inevitable Realities', 'Difficulty of Economic Independence', 'Difficulty of the Subjective Self-assertion'』, 『Contradictoriness of Decision Making: 'Decision Making Different from Own Mind', 'Conflicts between Neighboring'』, 『Self-rationalization of Decision Making: 'Self-comfort of Decision Making'』, 『Shifting Responsibility: 'Services Different from that of Family', 'Laking in Sincerity of Responsible Institution'』. Theoretical model about stigma of the family having old people admitted to nursing home by the research result in the above was able to be confirmed that it was expressed with the original form of thought of recursive system which continuously showing the inconsistency of decision making, rationalizing decision making, and shifting one's own responsibility in the process of accomplishing the duty of supporting old people. Based on the results, I discussed the meaning of stigma of families having old people admitted to nursing home and provided recommendations for future research.

• Korean Journal of Social Welfare Studies
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• v.40 no.2
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• pp.33-58
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• 2009

The main purpose of this study is to explore the structure of local government social welfare finance and tendency of changing structure and what affects the change. We select GuRoGu budget from 2000 to 2007 as one of local governments in Korea to perform the study goal. After we analyzed the contents of the budget, we have developed the framework of analysis for reclassifying local government welfare budget. First of all, we find utility of the framework of analysis which classify local government social welfare budget as target groups, properties, and the source of the finance. Secondly, the structure of local government welfare finance has changed for 8 years. The rate of finance for direct service has risen more than that for indirect service, and the rate of finance providing material(or service) type has risen more than that of providing monetary type. The rate of the finance from central government has grown up rapidly, whereas that from local government has fallen off. The hypotheses that the rate of financial self-reliance and the increase rate of social welfare expenditure to the previous year play a significant role to the rate of social welfare expenditure are not clear in our study. But we find the central government's effects to the local government welfare budget has grown up. So, we propose if we analyze the hypothesis of incrementalism, we must divide the effects of the previous year expenditure from the effects of central government's policy.