• Journal of Advanced Navigation Technology
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• v.26 no.3
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• pp.160-165
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• 2022

In this paper, we have proposed a magnetic resonant 6.78MHz WPT(wireless power transfer) technique which can be applied to a fixed transmitter and a receiver of varying relative distance and coil alignment, Power transmission characteristics are studied with the relative distance and misalignment ration of coil area between the transmitting and receiving coils. The coils are designed with the size of 60×80mm² by direct feeding method, and the characteristics are derived with the maximum relative distance of 50mm and horizontal area misalignment state of 0-40mm misalignment of coil center axis in the XY plane. The power transmission characteristics are compared between the 3D EM simulation and the measured data, and the power transmission shows larger than -3dB performance with the vertical distance of up to 30mm and 50% area misalignmment ratio. This work showsthe transmission characteristics according to relative distance and misalignment state between the cols and that direct feeding has advantage for the short relative distance and small misalignment ratio.

• Journal of the Korean Institute of Gas
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• v.26 no.3
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• pp.27-37
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• 2022

With the recent increase in the spread of ESS (Electric Storage System), the damage to human life and property is also rapidly increasing due to continuous fires caused by ESS. In the manufacture of urethane sandwich panels used in ESS, it is necessary to improve the flame retardant performance. In this study, in order to realize the flame retardant properties of flexible polyurethane foam, the effect of the tissue density of the product due to the change of the isocyanate functional group parameter that changes the physical properties of the product on the fire performance was studied. The product was manufactured by changing the density of the urethane structure, and combustion performance tests, gas toxicity tests, and smoke density tests were performed. As a result, it was confirmed that the total amount of heat released had excellent performance when the isocyanate functional group was high, and had no correlation with the maximum heat release rate. When the value of the isocyanate functional group was 2.7 or more, the collapse of the shape could be prevented. In the gas hazard test, the performance was increased when the isocyanate functional group was relatively high, so a flame retardant for the Char system, which had a dense structure and easy to form a carbonized film, was added. confirmed to be. Therefore, as a result of this study, it is thought that it will be possible to lay the foundation for the development of a flame retardant to replace the cheap urethane sandwich panel used in the past.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.1
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• pp.109-128
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• 2022

The precise inspection for safety and diagnosis (PISD) of tunnel has been conducted by the special act on safety control of public structures. However, the present assessment for the segmental lining of TBM tunnel has limitation such as: NDTs for integrity, segmental configuration for field inspection, and consideration for jacking system. Even if the number of TBM tunnel is less than 1% of enrolled facility in FMS, more attention to maintenance should be necessary due to its usage such as multi-use facility and national important facility. Compared to NATM tunnel, excavated by drilling and blasting and then installed lining by cast-in-place within 6~12 m, TBM tunnel is cut out ground by disk and cutter-bit and then assembled 7 pieces of precast segment, 1.2~1.4 m wide. Different features of design, construction, and maintenance should be considered to be more exact evaluation of TBM tunnel. The characteristics of defect is categorized and analyzed with 11 operational TBM tunnels in domestic subway. To be more comprehend various particular defects, foreign studies have been also adapted. Crack and leakage are categorized in 7 patterns. Breakage/spalling and corrosion are also grouped into 3 patterns. Patterned defects or damages are fed back in design, construction, and are useful guidelines for maintenance stage in future.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.705-712
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• 2021

The purpose of this study is to propose the features of autonomous DRT UX design based on level 5 autonomous vehicle applicable in 2027. As the scope of the study, the system focused on the interaction between the elderly and the in/outside of the vehicle, and the level 5 autonomous vehicle was the subject of the study. As of 2021, the targets for application were set from 60s to 90s. This study is different from previous studies in that it is a study on the features of autonomous DRT UX design that derives practical insights through direct communication with the elderly. As a research method, autonomous vehicle and DRT were theoretically considered through literature research, and based on this, cases of autonomous vehicle and DRT were analyzed. As a case study, generalization was conducted through interviews with the elderly, test-drive of autonomous vehicle, video production, survey, and VR test-drive of autonomous vehicle for the elderly. Ten features of autonomous DRT UX design were derived through focus group interview(FGI), and the derived features were classified into reservation, get on, input, driving, emergency, and get off. Through this study, I hope that it will contribute to improving mobility of the elderly and further accelerate the practical use of autonomous DRT.

• Journal of Appropriate Technology
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• v.6 no.2
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• pp.126-135
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• 2020

Recently, with the development of the 4th Industrial Revolution era and the popularization of technologies the maker movement is spreading worldwide in various ways for education, entrepreneurship, and solving social problems. This paper introduces a case of establishing and operating a maker space in Tanzania, East Africa, one of the developing countries. iTEC Tech-shop was established in the first half of 2018 at the Nelson Mandela African Institution of Science and Technology (NM-AIST) in Arusha, Tanzania by Innovative Technology and Energy Center (iTEC), and has been operating for nearly two years. With the allocation of empty warehouse space from NM-AIST, physical facilities were established through the purchase and installation of equipment and hand tools. Based on the advice from Idea Factory of Seoul National University and Fab-Lab Seoul, iTEC Tech-shop operational system were established. Through a total of 7 technical workshops, iTEC Tech-shop provided training courses for about 180 local personnel. In addition, the smart Techshop test-bed project was promoted in order to improve the operation level along with securing sustainability of the Techshop. The case of the iTEC Tech-shop could be a useful case for institutions or organizations promoting the maker movement to developing countries.

• Journal of Appropriate Technology
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• v.7 no.1
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• pp.51-58
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• 2021

This study proposes the design and implementation of a low-cost emergency ventilator which can be helpful during the COVID-19 pandemic where the supply of automatic ventilators is not smooth compared with the urgent demand worldwide. Easy implementation and lower price were made possible by using AMBU-bag and off-the-shelf embedded micro-controller board. Moreover, while 3D printing is used by companies and experts around the world to build prototype hardware, materials which are readily available from surrounding environments so that people in countries where it is difficult to access many advanced technologies could manufacture the system. The design features AMBU-bag automation, not use 3D printing, and it can contrl speed. By allowing speed control, ventilation can be performed according to the conditions of the patient being used. A complementary point in the study is that it is difficult to fix the start point of the wiper motor used first. A method for complementing this is a method for replacing the brush DC motor with a position feedback function. Secondly, the AMBU-bag may wear out in the long-term process of compressing the AMBU-bag because the arm and the fixing frame are made of wood. To complement this, the part of fixing frame and arm parts that the AMBU-bag touches need to be wrapped in a material such as silicon to minimize friction.

• Journal of Popular Narrative
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• v.27 no.1
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• pp.53-98
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• 2021

This paper examines the ways in which Hollywood feature films produced and widely circulated with the establishment of the studio system was consumed in the ethnically segregated Korean movie theaters in Kyǒngsǒng in the 1920s. Focusing on how those theaters appropriated what Hollywood represented, this paper has three objectives. First, from a historical and economic perspective, I will historicize the emergence of so-called prestige pictures and how movies became a branded product in that process. Second, I will also loot at how Chosǒn Theater, one of the earliest movie theaters in the Korean-resident area in Kyǒngsǒng who sought to be a prestigious movie palace actively exploited Hollywood brand, by foregrounding its Paramount connection, in particular. Lastly, through a close reading of weekly programmes and handbills, I will examine how these promotional print materials, as an intermediating medium, helped to supplement the audiences' viewing of Hollywood movies while creating loyal audiences.

• Korean Association of Arts Management
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• no.60
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• pp.69-92
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• 2021

This study was designed to insist on the need of introducing the position of dramaturgs as professionals at performance venues. A dramaturg is a professional staff member that proposes an artistic orientation in the making process of performing arts works such as play and dance. Dramaturgs are divided into production dramaturgs participating in individual works and permanent dramaturgs resident in the theater. In the present study, discussions developed around plans to make use of permanent dramaturgs at local public theaters. The study introduced the advantages of the dramaturg position at culture and arts centers serving as a public theater in the community and proposed institutional improvement measures for it. At a culture and arts center, a dramaturg will play the roles of expanding culture and arts service to local residents, increasing creative chances for local artists, contribution to the vitalization of local culture, and narrowing the cultural gap between the Seoul metropolitan region and the rest of the nation. The introduction of a permanent dramaturg system should be supported by efforts across various aspects including the revision of Culture and Arts Promotion Act and Public Performance Act, improvement of the management system of culture and arts centers, change of performance evaluation methods for performance venues, and introduction of a cultivation course for the public sector.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.1
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• pp.67-75
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• 2022

When acquiring a product having an OS, it is very important to identify the exact kernel version of the OS. This is because the product's administrator needs to keep checking whether a new vulnerability is found in the kernel version. Also, if there is an acquisition requirement for exclusion or inclusion of a specific kernel version, the kernel identification becomes critical to the acquisition decision. In the case of the Linux kernel used in various equipment, sometimes it becomes difficult to pinpoint the device's exact version. The reason is that many manufacturers often modify the kernel to produce their own firmware optimized for their device. Furthermore, if a kernel patch is applied to the modified kernel, it will be very different from its base kernel. Therefore, it is hard to identify the Linux kernel accurately by simple methods such as a specific file existence test. In this paper, we propose a static method to classify a specific kernel version by analyzing function names stored in the symbol table. In an experiment with 100 Linux devices, we correctly identified the Linux kernel version with 99% accuracy.

• Journal of the Korean Institute of Gas
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• v.26 no.6
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• pp.9-15
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• 2022

In order to verify the durability of the high-pressure hydrogen tank in the operating pressure range, a hydraulic rupture test should be performed. However, if the bubbles generated by the initial injection process of water are attached to the inner wall of the tank and remain, a sudden pressure change of the bubbles during the rupture of the pressurized tank may cause shock and noise. Therefore, in this study, the flow velocity required to remove the bubbles remaining on the inner wall of the tank was predicted through simplified formulas, and the shape of the injection nozzle to maintain the flow velocity was determined based on the shape of the hydrogen tank for the hydrogen bus. In addition, a numerical model was developed to predict the change in flow velocity according to the inlet pressure, and an experiment was performed through a model tank to prove the validity of the prediction result. As a result of the experiment, the flow velocity near the tank wall was similar to the predicted value of the analysis model, and when the inlet pressure was 1.5 to 5.5 bar, the minimum size of the removable bubble was predicted to be about 2.2 to 4.6 mm.