• Journal of Positioning, Navigation, and Timing
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• v.12 no.2
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• pp.185-200
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• 2023

The Korea Augmentation Satellite System (KASS) is the first satellite navigation enhancement system in Korea developed in compliance with international standards. Technologies accumulated during the development process should be spread to industries such as academia and serve as the basis for developing the domestic satellite navigation field. This paper introduces the development process from design to implementation, testing, and verification of KASS control systems (KCS). First, development standards, milestones, requirements, and interface standards are presented as KCS development methods, and major functional design, physical design, and hardware/software implementation are described based on the allocated requirements. Subsequently, the verification environment, procedures, and results of the development product are covered and the developed operational and maintenance procedures are described. In addition, based on the experience gained through the development, suggestions were made for beneficial technology development and organization when promoting satellite navigation projects in the future. Since this work has important historical value for the development of domestic satellite navigation, it is expected that the development results will be shared with academia and industry in the future and be used as basic data for similar development.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.8
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• pp.694-701
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• 2018

Civil aircraft noise certification standard is based on the ICAO Annex 16 Vol. 1. And, the standard uses A-Weighted SPL, EPNL and SEL method depending on the aircraft category. Korean noise standards, KAS 36 and other nation's CS 36 and FAR 36 noise standards were developed and revised according to the international noise standards, ICAO Annex 16. And, the national noise requirements are equivalent each other. The small airplane noise certification requires only take-off noise level with A-Weighted SPL in dB(A) unit. The first Korean aircraft noise certification was performed for the KC-100 certification in August 2012 with Korean authority and U.S. FAA. The noise certification requires much knowledge and experience in flight tests and noise data processing. In this study, the noise test requirements, test conditions and data correcting methods are shown with the test examples.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.3
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• pp.53-62
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• 2020

The study aims to provide some plausible explanation for why Vietnamese listed companies only stop at the level of truthful presentation of information related to accounting data through the opinion of independent auditors. The information is only at the level of compliance with the requirements of Circular 155/2015/TT-BTC in form, but in essence is sketchy. What factors affect the level of voluntary disclosure of listed companies in Vietnam? In order to identify the factors affecting voluntary information disclosure on annual reports of listed companies, the study collected data on annual reports of 122 companies listed on the stock market in Ho Chi Minh City in the period 2015-2018 and uses regression analysis methods. The research presents 8 factors affecting the level of voluntary information disclosure including: Firm size, Listed time, Profitability, Solvency, Separation of board of directors and executive director, Board size, Organizational ownership and Foreign ownership. Next, the study conducted descriptive statistical analysis correlation coefficient analysis to examine the correlation and relevance of independent variables measured by the scale ratio, testing multiple linear regression model. The results of the study show that factors listed time, profitability and organizational ownership affecting voluntary information disclosure on annual reports of listed companies in Vietnam.

• International Journal of Naval Architecture and Ocean Engineering
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• v.3 no.3
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• pp.181-192
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• 2011

Recently, the speed of change related with enterprise management is getting faster than ever owing to the competition among companies, technique diffusion, shortening of product lifecycle, excessive supply of market. For the example, the compliance condition (such as delivery date, product quality, etc.) from the ship owner is getting complicated and the needs for the new product such as FPSO, FSRU are coming to fore. This paradigm shift emphasize the rapid response rather than the competitive price, flexibility and agility rather than effective and optimal perspective for the domestic shipbuilding company. So, domestic shipbuilding companies have to secure agile and flexible ship production environment that could respond change of market and requirements of customers in order to continue a competitive edge in the world market. In this paper, I'm going to define a standard shipbuilding production management system by investigating the environment of domestic major shipbuilding companies. Also, I'm going to propose a unified ship production management and system for the operation of unified management through detail analysis of the activities and the data flow of ship production management. And, the system functions for the strategic approach of ship production management are investigated through the business administration tools such as performance pyramid, VDT and BSC. Lastly, the research of applying strategic KPI to the digital shipyard as virtual execution platform is conducted.

• Safety and Health at Work
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• v.10 no.4
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• pp.476-481
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• 2019

Background: Mystery shopping is a method in which a company monitors quality of service and employee conduct and compliance with regulations using an evaluator posing as a customer. It is a typical tool of customer-centered bureaucratic control insofar as it provides overall and standardized evaluation of intangible elements of customer service as well as physical elements of service environments. The purpose of this study is to examine how mystery shopping is related to the health status of service workers in South Korea. Methods: Data from semistructured interviews with 15 workers were collected from January to April 2019 to obtain information on service worker experiences with mystery shopping. Data were analyzed using the constant comparison method. Results: Mystery shopping limits worker autonomy and stiffens the workplace environment by standardizing and monitoring labor processes for service workers. In addition, mystery shopping heightens work stress through increased labor intensity. Five mechanisms by which mystery shopping affects service worker health are identified and comprise (1) multifaceted and multilayered surveillance, (2) evaluator subjectivity and irrational requirements, (3) standardized rules combined with high pressure to achieve sales, (4) self-esteem degradation because of evaluator results, and (5) musculoskeletal disorders because of strict adherence to labor processes based on evaluator results. Conclusion: Mystery shopping as an evaluation method should be reconsidered not only in terms of health problems but also in terms of organizational efficiency and issues of human rights.

• Journal of Biomedical Engineering Research
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• v.44 no.2
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• pp.99-108
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• 2023

According to the COVID-19, development of various medical software based on IoT(Internet of Things) was accelerated. Especially, interest in a central software system that can remotely monitor and control ventilators is increasing to solve problems related to the continuous increase in severe COVID-19 patients. Since medical device software is closely related to human life, this study aims to develop central monitoring system that can remotely monitor and control multiple ventilators in compliance with medical device software development standards and to verify performance of system. In addition, to ensure the safety and reliability of this central monitoring system, this study also specifies risk management requirements that can identify hazardous situations and evaluate potential hazards and confirms the implementation of cybersecurity to protect against potential cyber threats, which can have serious consequences for patient safety. As a result, we obtained medical device software manufacturing certificates from MFDS(Ministry of Food and Drug Safety) through technical documents about performance verification, risk management and cybersecurity application.

• Journal of the Korea Society of Computer and Information
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• v.20 no.3
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• pp.75-80
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• 2015

Vulnerability management is in compliance with security policies, and then, this is to ensure the continuity and availability of the business. In this paper, the application vulnerability management and IT infrastructure of the system is that it must be identified. And a viable vulnerability management plan should be drawn from the development phase. There are many that are not defined vulnerability in the area of identification and authentication, encryption, access control in identification and classification of vulnerabilities. They define the area without missing much in technical, managerial, and operational point of view. Determining whether the response of the identified vulnerability, and to select a countermeasure for eliminating the vulnerability.

• Steel and Composite Structures
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• v.2 no.3
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• pp.209-222
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• 2002

This paper describes the buckling phenomenon of a tubular truss with unsupported length through a full-scale test and presents a practical computational method for the design of the trusses allowing for the contribution of torsional stiffness against buckling, of which the effect has never been considered previously by others. The current practice for the design of a planar truss has largely been based on the linear elastic approach which cannot allow for the contribution of torsional stiffness and tension members in a structural system against buckling. The over-simplified analytical technique is unable to provide a realistic and an economical design to a structure. In this paper the stability theory is applied to the second-order analysis and design of the structural form, with detailed allowance for the instability and second-order effects in compliance with design code requirements. Finally, the paper demonstrates the application of the proposed method to the stability design of a commonly adopted truss system used in support of glass panels in which lateral bracing members are highly undesirable for economical and aesthetic reasons.

• Korea-Australia Rheology Journal
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• v.20 no.3
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• pp.165-173
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• 2008

Multiple particle tracking microrheology is used to characterize the viscoelastic properties of biomaterial and synthetic polymer gels near the liquid-solid transition. Probe particles are dispersed in the gel precursors, and their dynamics are measured as a function of the extent of reaction during gel formation. We interpret the dynamics using the generalized Stokes-Einstein relationship (GSER), using a form of the GSER that emphasizes the relationship between the probe particle mean-squared displacement and the material creep compliance. We show that long-standing concepts in gel bulk rheology are applicable to microrheological data, including time-cure superposition to identify the gel point and critical scaling exponents, and the power-law behavior of incipient network's viscoelastic response. These experiments provide valuable insight into the rheology, structure, and kinetics of gelling materials, and are especially powerful for studying the weak incipient networks of dilute gelators, as well as scarce materials, due to the small sample size requirements and rapid data acquisition.

• International Journal of Advanced Culture Technology
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• v.9 no.2
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• pp.72-79
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• 2021

This study is to develop a strategy to prepare an improvement strategy according to the environmental change of the hotel. Currently, domestic hotels are implementing marketing through food and beverage as a countermeasure against the sales decrease, and in order to develop effective marketing plan, 5 Force Model environmental analysis and STP analysis are analyzed. 5 Force Model Environmental Analysis showed that domestic hotels are facing various difficulties such as the expansion of accommodation sharing system, the decrease of Chinese tourists due to the THAAD problem, the increase of hotels, the introduction of PMS, the increase of minimum wage, the introduction of 52 hours work week, and the increase in product preference As an STP response strategy to correspond these difficulties, it is necessary to develop products for the main customers of the hotel food and beverage, such as those in the 20s-30s, the workers, smartphones and SNS users. And also hotels should seek ways to lower price of the product to the level desired by the user to compete against substitutes. In conclusion we suggest that hotels are committed to fulfilling their role by meeting guest safety and COVID-19 compliance requirements, but a focus on immediate cleanliness and quarantine against infectious diseases, like Airbnb, will enable greater growth.