• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.372-378
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• 2021

A body armor vest is a form of munition related directly to the safety and life of combatants. Therefore, it must meet the requirements for ballistic resistance. The ROK demands the performance of body armor vest meet the Level IIIA specified by the NIJ STD-0101.06 published by the US National Institute of Justice. This study performed acceptance tests on body armor vests. The factors for evaluating the ballistic resistance evaluated were not only whether it penetrates when shooting but also whether the BFS (Backface Signature) depth does not exceed 44 mm when it does not penetrate. The factors were assessed to determine if they were consistent or not. The BFS depth is affected by various test factors, such as the physical properties of the backing material and the changes in the amount of impact with the bullet velocity. In this study, an analysis of the bulletproof performance was performed by extracting the data with the same conditions using ANOVA to remove the influence of these external factors. The analysis revealed a correlation between the BFS depth, bullet velocity, vest conditions, and protection area. The mass production process was analyzed by estimating the Interval of BFS on each lot. Through this, a new methodology for ballistic resistance evaluation and paradigm for future quality assurance is suggested.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.9 no.2
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• pp.37-48
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• 1999

The Internet has been used as the academic researching purposes. Nowadays accordance with improving and being familiar with the World-Wide Web Many people are giving it a try to use the Internet as commerce markets. The noticeable example of internet-based use of the commerce is the Internet shopping mall. Using the WWW companies exhibit their products and users select the ones and take the payment for ones in the on-line Increasing the the Internet shopping mall there needs to be the countermeasure that companies and clients must verify each other. In this paper there are explained the development credit authentication system of the Internet shopping mall and the construction of the trusted environment clients can use Internet shopping mall. That is to develop the credit authentication system the credit-rating of Internet shopping mall can be sent securely and easily to clients and the information of credit-ranting cannot be eavesdropped.

• Journal of the Korean Society of Radiology
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• v.15 no.3
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• pp.307-312
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• 2021

In nuclear medicine, radioactive isotope tracers are administered to the human body to obtain and evaluate disease morphological information and biological function information. Dose calibrator is a device used to measure the radioactivity of a single nuclide in medical institutions. Administration of the correct dose to the human body acts as an important factor in diagnosis and treatment, and measurement through a dose calibrator before administration is the most important factor. Dose calibrator performs daily quality control after installation in each medical institution. Quality control is a means of guaranteeing quality control after installation, and is essential for improving the quality of treatment and promoting patient safety. Therefore, accurate and standardized performance evaluation methods should be established. In this study, 3D printing was used for quantitative evaluation of quality control by increasing the accuracy and standardization of quality control. When the 3D printer was installed and reproducibility was tested, the error range of the expected value and reading value decreased by 0.302% in the F-18 nuclide and 0.09% in the ^99mTc-pertechnate nuclide than when the 3D printer was installed. The error rate for other nuclides was also found to have a low error rate for reproducibility tests when 3D printing was installed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.76-84
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• 2021

The quality assurance activities can detect the factors that affect the quality based on risk identification in the course of mass production. Risk identification is conducted with risk analysis, and the risk analysis method for the rotorcraft landing system is selected by failure mode effects analysis (FMEA). FMEA is a method that detects the factors that can affect the product quality by combining severity, occurrence, and detectability. The results of FMEA were prioritized using the risk priority number. On the other hand, these methods have certain shortcomings because the severity, occurrence, detectability are weighted equally. Dempster-Shafer evidence theory can conduct uncertainty analysis for the opinions with personal reflections and subjectivity. Based on the theory, the belief function and the plausibility function can be formed. Moreover, the functions can be utilized to evaluate the belief rate and credibility. The system is exposed to impact during take-off and landing. Therefore, experts should manage failure modes in the course of mass production. In this paper, FMEA based on the Dempster-Shafer evidence theory is discussed to perform risk analysis regarding the failure mode of the rotorcraft landing system. The failure priority was evaluated depending on the factor values. The results were derived using belief and plausibility function graphs.

• Korean Journal of Construction Engineering and Management
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• v.23 no.2
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• pp.65-75
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• 2022

On 11 June 2021, the Supreme Court ruled that the judgment of the lower court was justified for the subject case, that the plaintiff could assert the defendant's liability for default due to incomplete performance even though the warranty period for defects which stipulated in the particular condition of the contract has expired. In Korean civil law, the concurrent between the exclusion period for defect warranty and the extinctive prescription for default liability is conceded, since the exclusion period and the extinctive prescription have their respective purposes in law, therefore these two should be judged by harmonizing them based on that they are mutually related. If the subject judgment is generalized, there is no reason to exist for the provisions of defect liability in the construction contract any longer. This study examines the subject judgments through the general theory and precedent case studies on the defect liability and default liability, then derived any problems that may arise if the subject judgment is generalized. In addition, based on a realistic model, it was suggested for a practical improvement method that both the provisions of the warranty period shall be changed realistic and to stipulate the character of its nature as written provisions in the contract.

• Journal of Korea Entertainment Industry Association
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• v.14 no.3
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• pp.139-148
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• 2020

Through this study, the policy proposals were intended to be presented to the head of the farming policy. Therefore, the meaning of this study is as follows. First, rather than judging the returning farmer on his own, he should provide sufficient information to consult with his family and increase access to agriculture. Second, by opening up SNS and YouTube to returning farmers, they should instill confidence in rural areas by providing them with information about the joy of rural life and the success of farming so that they can easily access information about rural life through villages, youth associations and women's associations. Efforts should be made to create vibrant rural areas by providing infrastructure around farmland, providing various amenities for settling young people and forming a family farmers' association. Third, the head of the return farming policy should come up with customized support policies for the return farming (e.g., one-year farm support, free farm support, institutional sales guarantee, tourism in advanced countries, modernization of farmland facilities). Public relations strategies should also be strengthened so that such policies can lead to agriculture. Finally, the government should provide subsidized economic activities (e.g. Airbnb, donation of expertise and work-related personnel before returning home, rural experience, etc.).

• The Journal of the Acoustical Society of Korea
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• v.41 no.5
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• pp.570-588
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• 2022

We scrutinized the acoustic outputs from the 70 shock wave generators of the 15 product models whose technical documents were available, among the 46 ballistic extracorporeal shock wave therapeutic devices of 11 domestic and 6 foreign manufacturers, approved by the Minster of Food & Drug Safety (Rep. Korea). We found that the acoustic Energy Flux Density (EFD), the most popular exposure parameter, was different by up to 563.64 times among shock wave generators at their minimum output settings and by up to 74.62 times at their maximum settings. In the same product model, the EFD was shown to vary depending on shock wave transmitters by up to 81.82 times at its minimum output setting and by up to 46.15 times at its maximum setting. The lowest EFD 0.013 mJ/mm² at the maximum output settings was much lower (2.1 %) than the maximum value 0.62 mJ/mm² at the minimum settings. The Large acoustic output differences (tens to hundreds of times)from the therapeutic devices approved for the same clinical indications imply that their therapeutic efficacy & safety may not be assured. The findings suggest the regulatory authority to revise her guideline to give clearer criteria for clinical approval and equality in performance, and recommend the authority to initiate a post-approval surveillance as well as a test in conformance between the data in technical documents and the real acoustic outputs clinically used.

• Korean small business review
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• v.42 no.4
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• pp.309-326
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• 2020

There often is information asymmetry between start-ups and the investors, which is because start-up companies in the early stages do not have track records. Meanwhile, since the government grants programs go through a fair and the intense competition process, the government grants can provide a more objective information for start-ups in the early stages and perform a signal function that guarantees a company's capabilities and potential. This study confirms the quantitative relationship between government grants and investment attraction by using the hurdler model. We found that, although there is the proportionate relationship between the scale of government grants and that of external funds, more than a certain amount of government grants is required for technology-based start-ups to exceed the stage of attracting their first external funds. Our findings suggest that it is necessary to consider the hurdles structure in the study of signaling theory perspective, as the mechanisms for determining whether or not to attract external funds are different from determining the level of external funds. In addition, differentiated policy support is needed to help early-stage technology start-ups go beyond the threshold of investment attraction-the creation of a 'threshold effect'.

• Journal of the Korea Computer Graphics Society
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• v.28 no.5
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• pp.1-11
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• 2022

Game engines have the advantage of enabling efficient content production, such as reducing development time, with minimal visual quality guarantees and support for multi-platforms. Recently, game engines have provided various functions that can easily, quickly, and effectively produce immersive content using virtual reality (VR) HMD. Therefore, this study conducts a comparative study on the development environment in VR content production using Oculus Quest 2 HMD, focusing on Unity and Unreal game engines, which are widely used in the content production industry, including games. First, we compare the basic setup process of building a development environment using Oculus Quest 2 HMD and a dedicated controller based on a VR template project that includes the minimum functions and settings provided by each engine. Next, we present a simple experience environment that can interact in a virtual environment and compare the development environment to use a dedicated controller and the process of building a development environment that directly utilizes hands through the hand tracking function provided by Oculus Quest 2. Through this process, we will understand the basic process of building a VR development environment, and at the same time, we will check the characteristics and differences of the engine and use it as a research that can be applied to various immersive content production.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.4
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• pp.293-297
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• 2022

In 2022, Korea reported a total of 224 perfusionists, employing nurses or clinical laboratory technologists (also known as medical technologists) to provide hospital self-education or reliable education. In 2021, the total number of perfusionists in Japan was 2,100, mainly supported by clinical engineering technologists. During the same period, the number of perfusionists reported in the United States was 4,212, who had received training in the master's program, post-bachelor certificate program, and bachelor's program. Most personnel in the USA were graduates of healthcare sciences or life sciences. Perfusionists must be knowledgeable in heart anatomy, physiology, pharmacology, pathology, hemodynamics, laboratory analysis, and quality assurance, as well as techniques to operate the cardiopulmonary bypass machine (heart-lung bypass machine). These are jobs similarly handled by clinical laboratory technologists. The importance of perfusionists became more prominent during two major crises: the MERS-CoV and COVID-19 pandemic. Currently, perfusionists play a significant role in the rapidly expanding field of extracorporeal membrane oxygenation (ECMO) and extracorporeal circulation during cardiac surgery. Results of the current study indicate that hospitals offering cardiac surgery and infectious disease hospitalization need to be institutionalized to secure a certain number of qualified perfusionists. In the future, we look forward to establishing a perfusion technology association under the Korean Society for Clinical Laboratory Physiology to provide academic exchanges.